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1

Quantifying diffuse and discrete venting at the Tour Eiffel vent site, Lucky Strike hydrothermal field  

NASA Astrophysics Data System (ADS)

The relative heat carried by diffuse versus discrete venting of hydrothermal fluids at mid-ocean ridges is poorly constrained and likely varies among vent sites. Estimates of the proportion of heat carried by diffuse flow range from 0% to 100% of the total axial heat flux. Here, we present an approach that integrates imagery, video, and temperature measurements to accurately estimate this partitioning at a single vent site, Tour Eiffel in the Lucky Strike hydrothermal field along the Mid-Atlantic Ridge. Fluid temperatures, photographic mosaics of the vent site, and video sequences of fluid flow were acquired during the Bathyluck'09 cruise (Fall, 2009) and the Momarsat'10 cruise (Summer, 2010) to the Lucky Strike hydrothermal field by the ROV Victor6000 aboard the French research vessel the "Pourquoi Pas"? (IFREMER, France). We use two optical methods to calculate the velocities of imaged hydrothermal fluids: (1) for diffuse venting, Diffuse Flow Velocimetry tracks the displacement of refractive index anomalies through time, and (2) for discrete jets, Particle Image Velocimetry tracks eddies by cross-correlation of pixel intensities between subsequent images. To circumvent video blurring associated with rapid velocities at vent orifices, exit velocities at discrete vents are calculated from the best fit of the observed velocity field to a model of a steady state turbulent plume where we vary the model vent radius and fluid exit velocity. Our results yield vertical velocities of diffuse effluent between 0.9 cm s-1 and 11.1 cm s-1 for fluid temperatures between 3°C and 33.5°C above that of ambient seawater, and exit velocities of discrete jets between 22 cm s-1 and 119 cm s-1 for fluid temperatures between 200°C and 301°C above ambient seawater. Using the calculated fluid velocities, temperature measurements, and photo mosaics of the actively venting areas, we calculate a heat flux due to diffuse venting from thin fractures of 3.15 ± 2.22 MW, discrete venting of 1.07 ± 0.66 MW, and, by incorporating previous estimates of diffuse heat flux density from Tour Eiffel, diffuse flux from the main sulfide mound of ˜15.6 MW. We estimate that the total integrated heat flux from the Tour Eiffel site is 19.82 ± 2.88 MW and that the ratio of diffuse to discrete heat flux is ˜18. We discuss the implication of these results for the characterization of different vent sites within Lucky Strike and in the context of a compilation of all available measurements of the ratio of diffuse to discrete heat flux.

Mittelstaedt, Eric; EscartíN, Javier; Gracias, Nuno; Olive, Jean-Arthur; Barreyre, Thibaut; Davaille, Anne; Cannat, Mathilde; Garcia, Rafael

2012-04-01

2

Diffuse versus discrete venting at the Tour Eiffel vent site, Lucky Strike hydrothermal field  

NASA Astrophysics Data System (ADS)

Two styles of fluid flow at the seafloor are widely recognized: (1) localized outflows of high temperature (>300°C) fluids, often black or grey color in color (“black smokers”) and (2) diffuse, lower temperature (<100°C), fluids typically transparent and which escape through fractures, porous rock, and sediment. The partitioning of heat flux between these two types of hydrothermal venting is debated and estimates of the proportion of heat carried by diffuse flow at ridge axes range from 20% to 90% of the total axial heat flux. Here, we attempt to improve estimates of this partitioning by carefully characterizing the heat fluxes carried by diffuse and discrete flows at a single vent site, Tour Eiffel in the Lucky Strike hydrothermal field along the Mid-Atlantic Ridge. Fluid temperature and video data were acquired during the recent Bathyluck’09 cruise to the Lucky Strike hydrothermal field (September, 2009) by Victor aboard “Pourquoi Pas?” (IFREMER, France). Temperature measurements were made of fluid exiting discrete vents, of diffuse effluents immediately above the seafloor, and of vertical temperature gradients within discrete hydrothermal plumes. Video data allow us to calculate the fluid velocity field associated with these outflows: for diffuse fluids, Diffuse Flow Velocimetry tracks the displacement of refractive index anomalies through time; for individual hydrothermal plumes, Particle Image Velocimetry tracks eddies by cross-correlation of pixels intensities between subsequent images. Diffuse fluids exhibit temperatures of 8-60°C and fluid velocities of ~1-10 cm s-1. Discrete outflows at 204-300°C have velocities of ~1-2 m s-1. Combined fluid flow velocities, temperature measurements, and full image mosaics of the actively venting areas are used to estimate heat flux of both individual discrete vents and diffuse outflow. The total integrated heat flux and the partitioning between diffuse and discrete venting at Tour Eiffel, and its implications for the nature of hydrothermal activity across the Lucky Strike site are discussed along with the implications for crustal permeability, associated ecosystems, and mid-ocean ridge processes.

Mittelstaedt, E. L.; Escartin, J.; Gracias, N.; Olive, J. L.; Barreyre, T.; Davaille, A. B.; Cannat, M.

2010-12-01

3

Stabilization of dissolved trace metals at hydrothermal vent sites: Impact on their marine biogeochemical cycles  

NASA Astrophysics Data System (ADS)

Hydrothermal vents have long been neglected as a significant source of several bioactive trace metals as it was assumed that elements such as Fe, Mn, and Cu etc., precipitate in extensor forming poly-metallic sulfide and oxy-hydroxy sediments in the relative vicinity of the emanation site. However, recently this paradigm has been reviewed since the stabilization of dissolved Fe and Cu from hydrothermal vents was observed [1, 2] and increased concentrations of trace metals can be traced from their hydrothermal source thousands of kilometres through the ocean basins [3]. Furthermore several independent modelling attempts have shown that not only a stabilization of dissolved hydrothermal Fe and Cu is possible [4] but also that hydrothermalism must be a significant source of Fe to be able to balance the Fe-biogeochemical cycle [5]. Here we present new data that gives further evidence of the presence of copper stabilising organic and inorganic compounds in samples characterized by hydrothermal input. We can show that there are systematic differences in copper-complexing ligands at different vent sites such as 5°S on the Mid Atlantic Ridge, Brother Volcano on the Kermadec Arc, and some shallow hydrothermal CO2 seeps in the Bay of Plenty, New Zealand and the Mediterranean Sea. Quantitative and qualitative voltammetric data convincingly indicates that inorganic sulphur and organic thiols form the majority of the strong copper-complexing ligand pool in many of these hydrothermal samples. On average, the high temperature vents had a significantly higher copper binding capacity than the diffuse vents due to higher inorganic sulphur species concentrations. References: [1] Sander, S. G., et al. 2007. Organic complexation of copper in deep-sea hydrothermal vent systems. Environmental Chemistry 4: 81-89 [2] Bennett, S. A., et al. 2008. The distribution and stabilisation of dissolved Fe in deep-sea hydrothermal plumes. Earth and Planetary Science Letters 270: 157-167. [3] Wu J. et al. 2011. Dissolved iron anomaly in the deep tropical-subtropical Pacific: Evidence for long-range transport of hydrothermal iron. Geochimica et Cosmochimica Acta 75: 460-468. [4] Sander, S. G., and A. Koschinsky. 2011. Metal flux from hydrothermal vents increased by organic complexation. Nature Geoscience 4: 145-150 DOI:10.1038/ngeo1088. [5] Tagliabue, A. et al. 2010. Hydrothermal contribution to the oceanic dissolved iron inventory. Nature Geoscience 3: 252-256 DOI: 10.1038/NGEO818

Sander, Sylvia G.; Powell, Zach D.; Koschinsky, Andrea; Kuzmanovski, Stefan; Kleint, Charlotte

2014-05-01

4

Dive and Discover's Deeper Discovery: Hydrothermal Vents  

NSDL National Science Digital Library

Dive and Discover is an interactive distance learning web site designed to immerse you in the excitement of discovery and exploration of the deep seafloor. On this particular website, Dive and Discover takes you on a deeper discovery of hydrothermal vents. This site features an introduction to hydrothermal vent systems, including vent basics, vents around the world, chemistry, boiling points, interactive diagrams, videos, a quiz, and links to selected Dive and Discover hydrothermal vent-related seafloor expeditions. This web page also provides links to other Deeper Discovery topics, Dive and Discover seafloor expeditions, a teacher's page, and further Dive and Discover information.

2010-04-12

5

Food Web Structure at South Su, Solwara 1 and Solwara 8 Hydrothermal Vent Sites (Manus Basin)  

NASA Astrophysics Data System (ADS)

A robust understanding of food webs in chemoautotrophically based hydrothermal vent ecosystems requires quantifying the input of local bacterial chemoautoptrophic production vs. photosynthetically derived debris from surface waters. As an initial step towards this goal for vent communities in Papua New Guinea's Manus Basin, we use isotopic ratios of carbon, nitrogen and sulfur to describe trophic relations among 17 invertebrate genera collected in July 2008 at the Solwara 1, Solwara 8 and South Su hydrothermal vent beds. Prior stable isotope work by Erickson, Macko and Van Dover (unpublished) at Manus Basin vent sites suggests that we will see relatively depleted ä13C and ä15N values for the primary consumers Ifremeria, Alviniconcha and Olgasolaris compared to secondary consumers like the mobile, scavenging genera Munidopsis, Austinograea, Alvinocaris and Chorocaris, sessile suspension feeders of the genera Eochinolasmus and Vulcanolepas, and the predatory sponge Abyssocladia. We further hypothesize that mobile fauna will exhibit greater within-genus variance of ä13C, ä15N and ä34S values than sessile genera due to mobile organisms' ability to forage for photosynthetically derived detritus.

Honig, D. L.; Hsing, P.; Jones, R.; Schultz, T.; Sobel, A.; Thaler, A.; van Dover, C. L.

2008-12-01

6

Liquid Carbon Dioxide Venting at the Champagne Hydrothermal Site, NW Eifuku Volcano, Mariana Arc  

NASA Astrophysics Data System (ADS)

In March/April 2004, submersible dives with the remotely-operated vehicle ROPOS discovered an unusual CO2-rich hydrothermal system near the summit of NW Eifuku, a submarine volcano located at 21.49° N, 144.04° E in the northern Mariana Arc. Although several sites of hydrothermal discharge were located on NW Eifuku, the most intense venting was found at 1600-m depth at the Champagne site, slightly west of the volcano summit. The Champagne site was found to be discharging two distinct fluids into the ocean: a) several small white chimneys were emitting milky 103° C gas-rich hydrothermal fluid with at least millimolar levels of H2S and b) cold (< 4° C) droplets coated with a milky skin were rising slowly from the sediment. These droplets were later determined to consist mainly of liquid CO2, with H2S as a probable secondary component. The droplets were sticky, and did not tend to coalesce into larger droplets, even though they adhered to the ROV like clumps of grapes. The film coating the droplets was assumed to be CO2 hydrate (or clathrate) which is known to form whenever liquid CO2 contacts water under these P,T conditions. Samples of the 103° C hydrothermal fluids were collected in special gas-tight titanium sampling bottles that were able to withstand the high internal pressures created by the dissolved gases. The Champagne hydrothermal fluids contained a surprising 2.3 moles/kg of CO2, an order of magnitude higher than any CO2 values previously reported for submarine hydrothermal fluids. The overall gas composition was 87% CO2, < 0.1% CH4, < 2 ppm H2, 0.012 mM/kg 4He, with the remaining 13% (322 mM/kg) assumed to be sulfur gases (H2S, SO2, etc.). (Additional analyses planned will confirm the speciation of this sulfur gas component). The helium had R/RA = 7.3, typical of subduction zone systems (R = 3He/4He and RA = Rair). Isotopic analysis of the CO2 yielded ? 13C = -1.75 ‰ , much heavier than the -6.0 ‰ typical for carbon in MOR vent fluids. The C/3He ratio was ~2.2 x 1010, an order of magnitude higher than the average value of 2 x 109 found in MOR vent fluids. The ? 13C and C/3He values suggest a substantial contribution to the carbon from subducted carbonates rather than mantle carbon. The Champagne site is only the second locality where liquid CO2 has been observed venting into the deep sea (the other reported location is in the Okinawa Trough, see Sakai et al., 1990). Because of the presence of liquid CO2 in proximity to hydrothermal organisms, the Champagne site may prove to be a valuable natural laboratory for studying the effects of high CO2 concentrations on marine ecosystems.

Lupton, J.; Lilley, M.; Butterfield, D.; Evans, L.; Embley, R.; Olson, E.; Proskurowski, G.; Resing, J.; Roe, K.; Greene, R.; Lebon, G.

2004-12-01

7

Microbial Utilization of Naturally Occurring Hydrocarbons at the Guaymas Basin Hydrothermal Vent Site  

PubMed Central

The Guaymas Basin (Gulf of California; depth, 2,000 m) is a site of hydrothermal activity in which petroliferous material is formed by thermal alteration of deposited planktonic and terrestrial organic matter. We investigated certain components of these naturally occurring hydrocarbons as potential carbon sources for a specific microflora at these deep-sea vent sites. Respiratory conversion of [1-14C]hexadecane and [1(4,5,8)-14C]naphthalene to 14CO2 was observed at 4°C and 25°C, and some was observed at 55°C, but none was observed at 80°C. Bacterial isolates were capable of growing on both substrates as the sole carbon source. All isolates were aerobic and mesophilic with respect to growth on hydrocarbons but also grew at low temperatures (4 to 5°C). These results correlate well with previous geochemical analyses, indicating microbial hydrocarbon degradation, and show that at least some of the thermally produced hydrocarbons at Guaymas Basin are significant carbon sources to vent microbiota.

Bazylinski, Dennis A.; Wirsen, Carl O.; Jannasch, Holger W.

1989-01-01

8

Hydrothermal vents: a novel theory of illumination  

Microsoft Academic Search

There are many theories revolving around the source of non-thermally based visible light emissions from deep-sea hydrothermal vents. Although many of these theories have been proven possible in a controlled laboratory environment, none have been directly linked to hydrothermal vents through on-site experimentation and evaluation. Nor have any of them conclusively lain to rest the unanswerable and unpredictable source and

D. J. Bogorff

2005-01-01

9

Iron (II) distribution and oxidation kinetics in hydrothermal plumes at the Kairei and Edmond vent sites, Indian Ocean  

NASA Astrophysics Data System (ADS)

Deep-sea hydrothermal activity cycles the entire volume of the global ocean through deep-sea hydrothermal plumes at least every 4-8 × 10 3 a, a rapid timescale that is comparable to global deep-ocean mixing. An important process within hydrothermal plumes is the oxidation of dissolved iron discharged with vent fluids, leading to the co-precipitation of many other vent-sourced metals, thus, modifying gross hydrothermal fluxes to the deep ocean, and acting as a net sink in the ocean chemical budgets of certain key tracers. Here, we report direct measurements of dissolved Fe(II) oxidation rates from two recently discovered Indian Ocean vent sites that are intermediate between Pacific and Atlantic values, thus demonstrating that the rate of iron oxidation and formation of scavenging Fe(III) solid phases, in hydrothermal plumes varies systematically along the global deep-ocean "conveyor." The average pseudo first-order rate constant for the oxidation reaction is 0.303 h -1 and the corresponding half-life 2.31 h. The rate plots show some curvature, however, indicating additional processes, possibly interactions with organic matter, may also influence the net oxidation/removal rate. Different rates of oxidation of iron in hydrothermal plumes in different ocean basins have important implications for the dispersion of produced oxide phases, which in turn may impact on uptake of other metals from seawater and deposition into underlying ridge-crest and ridge flank sediments.

Statham, P. J.; German, C. R.; Connelly, D. P.

2005-08-01

10

Dominance of one bacterial phylotype at a Mid-Atlantic Ridge hydrothermal vent site.  

PubMed

Microbial community structure in natural environments has remained largely unexplored yet is generally considered to be complex. It is shown here that in a Mid-Atlantic Ridge hydrothermal vent habitat, where food webs depend on prokaryotic primary production, the surface microbial community consists largely of only one bacterial phylogenetic type (phylotype) as indicated by the dominance of a single 16S rRNA sequence. The main part of its population occurs as an ectosymbiont on the dominant animals, the shrimp Rimicaris exoculata, where it grows as a monoculture within the carapace and on the extremities. However, the same bacteria are also the major microbial component of the free-living substrate community. Phylogenetically, this type forms a distinct branch within the epsilon-Proteobacteria. This is different from all previously studied chemoautotrophic endo- and ectosymbioses from hydrothermal vents and other sulfidic habitats in which all the bacterial members cluster within the gamma-Proteobacteria. PMID:7543678

Polz, M F; Cavanaugh, C M

1995-08-01

11

Lithosphere-biosphere interaction at a shallow-sea hydrothermal vent site; Hot Lake, Panarea, Italy  

NASA Astrophysics Data System (ADS)

Deep-Sea hydrothermal systems are unique habitats for microbial life with primary production based on chemosynthesis and are considered to be windows to the subsurface biosphere. It is often overlooked, however, that their far more accessible shallow-sea counterparts are also valuable targets to study the effects of hydrothermal activity on geology, seawater chemistry and finally, on microbial life. Such an area of shallow marine hydrothermal venting is observed approximately 2.5 km east of Panarea Island (Sicily, Italy). This system is characterized by fluid temperatures of up to 135° C, gas emissions dominated by CO2 and precipitation of elemental sulfur on the seafloor. In an interdisciplinary project to investigate the influence of geofuels on marine microbiota, sediment cores and pore fluids were sampled for geological and geochemical analyses. An attempt was made to link these geochemical data with a characterization of the microbial community. One of the investigated sites (Lago Caldo, Hot Lake) is an oval-shaped (~10 by 6 meters) shallow (~2.5 m deep) depression covered by elemental sulfur. The sediments in this depression are strongly affected by hydrothermal activity: the pH of pore fluids is in a range between 5 and 6; the salinity is approximately two times higher than seawater. In situ temperatures of 36° C and 74° C (10 cm sediment depth) at two different locations within Hot Lake indicate variability in hydrothermal flux. The sediment surface layer is anoxic, and with increasing depth from the sediment-water interface, sulfate concentrations decrease from ~30 mM to less than 10 mM, whereas sulfide concentrations increase from less than 50 ?m to ~1000 ?m at 25 cm sediment depth, thus suggesting a higher potential for energy gain based on sulfur disequilibrium. As indicated by the variability in the sediment temperatures at 10 cm, fluid fluxes and mixing with seawater is not found to be uniform at Hot Lake. This is reflected in variability of the pore fluids geochemistry (anions, cations and stable isotope composition of water and sulfate) of depth profiles. DNA-fingerprinting techniques (DGGE, ARISA) revealed distinctly different bacterial 16S rRNA gene patterns for three separate sediment cores taken at Hot Lake. Intact polar lipid (IPL) biomarker analysis revealed a dominance of bacterial over archaeal biomass. The bacterial IPLs were mainly comprised of diether and diester phospholipids and ornithine lipids, indicative of viable thermophilic sulfate-reducing and acidophilic sulfide-oxidizing bacteria. Bacterial IPL abundance was highest in the sediment surface layer. Fluorescence in situ hybridization showed that with increasing depth and temperature, the abundance of archaea increased relative to that of bacteria. Comparative 16S rRNA gene analysis revealed a moderate diversity of bacteria, and a dominance of epsilonproteobacterial sequences. Cultured representatives of the detected epsilonproteobacterial classes are known to catalyze elemental sulfur reduction and oxidation reactions and to mediate the formation of iron-sulfides, including framboidal pyrite, which was found in sediment samples. We conclude that mixing between hydrothermal fluids and seawater leads to distinctly different temperature gradients and ecological niches in Hot Lake sediments. From the geochemical profiles and a preliminary characterization of the microbiological community, we found strong evidence of sulfur-related metabolism. Further investigation of certain clusters of bacteria and archaea as well as gene expression analysis will give us a deeper understanding of the interaction between geosphere and biosphere at this site in the future.

Huang, Chia-I.; Amann, Rudolf; Amend, Jan P.; Bach, Wolfgang; Brunner, Benjamin; Meyerdierks, Anke; Price, Roy E.; Schubotz, Florence; Summons, Roger; Wenzhöfer, Frank

2010-05-01

12

Dominance of One Bacterial Phylotype at a Mid-Atlantic Ridge Hydrothermal Vent Site  

Microsoft Academic Search

Microbial community structure in natural environments has remained largely unexplored yet is generally considered to be complex. It is shown here that in a Mid-Atlantic Ridge hydrothermal vent habitat, where food webs depend on prokaryotic primary production, the surface microbial community consists largely of only one bacterial phylogenetic type (phylotype) as indicated by the dominance of a single 16S rRNA

Martin F. Polz; Colleen M. Cavanaugh

1995-01-01

13

The Discovery of Marine Hydrothermal Vents  

NSDL National Science Digital Library

As part of OceanLink, a website dedicated to ocean education, this site gives an overview of the discovery, geology and ecology of marine hydrothermal vents. The site also provides a menu of links to access other OceanLink pages for further ocean-related information.

Oceanlink

14

Vision in hydrothermal vent shrimp.  

PubMed

Bresiliid shrimp from hydrothermal vents on the Mid-Atlantic Ridge have non-imaging eyes adapted for photodetection in light environments of very low intensity. Comparison of retinal structures between both vent shrimp and surface-dwelling shrimp with imaging eyes, and between juvenile and adult vent shrimp, suggests that vent shrimp have evolved from ancestors that lived in a light environment with bright cyclic lighting. Whether the vent shrimp live in swarms and have large dorsal eyes or live in sparse groupings and have large anterior eyes, the basic retinal adaptations are the same across species. Retinal adaptations in adult vent shrimp include the loss of dioptrics, enlargement of both the rhabdomeral segment of the photoreceptors and the light-sensitive rhabdomere therein, attenuation of the arhabdomeral segment of the photoreceptors, reduction of black screening pigment, development of a white diffusing layer behind the photoreceptors, and the loss of rhabdom turnover. PMID:11079388

Chamberlain, S C

2000-09-29

15

Vision in hydrothermal vent shrimp.  

PubMed Central

Bresiliid shrimp from hydrothermal vents on the Mid-Atlantic Ridge have non-imaging eyes adapted for photodetection in light environments of very low intensity. Comparison of retinal structures between both vent shrimp and surface-dwelling shrimp with imaging eyes, and between juvenile and adult vent shrimp, suggests that vent shrimp have evolved from ancestors that lived in a light environment with bright cyclic lighting. Whether the vent shrimp live in swarms and have large dorsal eyes or live in sparse groupings and have large anterior eyes, the basic retinal adaptations are the same across species. Retinal adaptations in adult vent shrimp include the loss of dioptrics, enlargement of both the rhabdomeral segment of the photoreceptors and the light-sensitive rhabdomere therein, attenuation of the arhabdomeral segment of the photoreceptors, reduction of black screening pigment, development of a white diffusing layer behind the photoreceptors, and the loss of rhabdom turnover.

Chamberlain, S C

2000-01-01

16

Mantle to hydrothermal vent sites of the Southern Mariana Trough back-arc Basin: Results from the Taiga Project  

NASA Astrophysics Data System (ADS)

The southern Mariana Trough back-arc basin shows an EPR type axial relief in morphology and constant low mantle Bouguer anomaly along the spreading axis (Kitada et al., 2006), suggesting abundance of magma supply, even though the full spreading rate of 40 km/Myr is categorized as slow spreading. Further, five hydrothermal vent sites exist within 5 km near the spreading axis at 13 N; two sites on the spreading axis, one site at the eastern foot of the axial high, and two sites on an off-axis knoll. We selected this area as one of three integrated target sites for the Taiga Project, and we conducted series of JAMSTEC research cruises for four different types of geophysical surveys, together with dive observation and samplings by the submersible Shinkai6500. The geophysical surveys consists of 1) a marine magnetotelluric (MT) survey of a 130 km length transect across the spreading axis using 10 ocean bottom electro-magnetometers, 2) a 15 km scale seismic reflection/refraction survey and seismicity observation using 9 ocean bottom seismometers (OBS), 3) near-bottom acoustic and magnetic mapping around all the hydrothermal sites using the AUV Urashima, and 4) a magnetometric resistivity (MMR) survey around the on-axis hydrothermal sites. Two-dimensional electrical resistivity structure of the upper mantle from the MT analysis shows highly asymmetry, which may be affected by hydration driven by water release from the subducting slab; that may result in abundant magma supply to support EPR type axial morphology. Three months OBS observation shows that the seismicity near the hydrothermal vent sites is very low, suggesting that hydrothermal activities are not related to tectonic stress. Moreover, the morphology of the mound and knoll near the three off-axis hydrothermal sites shows undeformed features without any faults, suggesting that their formation is closely related to an off-axis magma upwelling system rather than fault systems. The two on-axis hydrothermal sites (the Yamanaka and Snail sites) are located near the end of a 4th order spreading segment based on the observed offset of the neo-volcanic zone, suggesting that they are possibly locally developed in association with diking events in the segment. But the diking is probably an episodic event to provide heat source for each hydrothermal site, because of very low seismicity. Clear magnetization low at four hydrothermal vent sites except the Yamanaka site suggests that the hydrothermal activities have continued for long enough periods in wide enough areas to reduce the magnetic remanence of the crustal rocks. The different feature in the Yamanaka site suggests its activity has been short and/or small. The MMR results support this difference because low electrical resistivity region with 200 meter scale is located only at the Snail site but not at the Yamanaka site; the low resistivity region is probably due to the existence of hot crustal pore fluid.

Seama, N.; Okino, K.; Nogi, Y.; Sato, T.; Matsuno, T.; Yoshikawa, S.; Mochizuki, N.; Shinohara, M.

2012-12-01

17

Dispatch from the Deep: Hydrothermal Vent Formation  

NSDL National Science Digital Library

This dispatch from the research vessel Atlantis discusses how hydrothermal vents are formed and why scientists monitor minute temperature changes around them. It includes an account of preparing temperature probes to be deployed for a year-long study, an explanation of deep sea vents and their hydrothermal nature and an explanation of why deep sea vents seem to spew black smoke.

18

Chemosynthetic microbial activity at Mid-Atlantic Ridge hydrothermal vent sites  

NASA Astrophysics Data System (ADS)

Chemosynthetic production of microbial biomass, determined by 14CO2 fixation and enzymatic (RuBisCo) activity, at the Mid-Atlantic Ridge (MAR) 23° and 26°N vent sites was found in various niches: warm water emissions, loosely rock-attached flocculent material, dense morphologically diverse bacterial mats covering the surfaces of polymetal sulfide deposits, and filamentous microbes on the carapaces of shrimp (Rimicaris exoculata). The bacterial mats on polymetal sulfide surfaces contained unicellular and filamentous bacteria which appeared to use as their chemolithotrophic electron or energy source either dissolved reduced minerals from vent emissions, mainly sulfur compounds, or solid metal sulfide deposits, mainly pyrite. Moderately thermophilic Chemosynthetic activity was observed in carbon dioxide fixation experiments and in enrichments, but no thermophilic aerobic sulfur oxidizers could be isolated. Both obligate and facultative chemoautotrophs growing at mesophilic temperatures were isolated from all chemosynthetically active surface scrapings. The obligate autotrophs could oxidize sterilized MAR natural sulfide deposits as well as technical pyrite at near neutral pH, in addition to dissolved reduced sulfur compounds. While the grazing by shrimp on the surface mats of MAR metal sulfide deposits was observed and deemed important, the animals' primary occurrence in dense swarms near vent emissions suggests that they were feeding at these sites, where conditions for Chemosynthetic growth of their filamentous microbial epiflora were optimal. The data show that the transformation of geothermal energy at the massive polymetal sulfide deposits of the MAR is based on the lithoautotrophic oxidation of soluble sulfides and pyrites into microbial biomass.

Wirsen, Carl O.; Jannasch, Holger W.; Molyneaux, Stephen J.

1993-06-01

19

Tonga - Kermadec Arc Calderas as Sites of Hydrothermal Venting: A Review of Caldera Morphology and Structure  

NASA Astrophysics Data System (ADS)

Within the 870 km long sector of the Tonga - Kermadec arc (between 35°S and 21°S), submarine hydrothermal venting is dominantly hosted within calderas associated with silicic eruptives. Over 50 individual >1 km wide calderas have been identified from five multibeam mapping surveys from 2002 - 2007. Caldera distribution is mostly, though not exclusively, along the central - northern Kermadec and southern Tonga arc sectors. In contrast, metrics of caldera morphology are mostly consistent along the arc; average caldera floor water-depth is 1050 m (range 1860 - 260 m), average caldera long axis is 4.9 km (range 11.6 - 1 km), and average caldera rim water-depth is 800 m (range 1500 - 160 m). As in the onshore extension of the arc (Taupo Volcanic Zone), regional arc and backarc extension strongly controls caldera structure; caldera elongation (average length:width ratio of 1.26) is orientated predominantly orthogonal to the basement rift fabric. Various styles of caldera collapse (including trap-door and funnel structures) are recognised from both multibeam and multi-channel seismic reflection data. More than half of the calderas show evidence of repetitive and nested collapse. Caldera breaching and rim collapse are common, and can be associated with mass-gravity pyroclastic debris flows, imaged as large-scale sediment bed-forms in multibeam and multi-channel seismic data. Similarly, post-collapse volcanism (but not structural resurgence) is common with both intra-caldera dome construction, and formation of cone vents and explosion pits around the caldera rim. Such post-collapse volcanism is variable in composition, however, intra-caldera dome and rim eruptives are commonly rhyolitic and basaltic, respectively.

Wright, I. C.; Graham, I. J.; Stoffers, P.; Wilson, C. J.

2007-12-01

20

Post-drilling hydrothermal vent and associated biological activities seen through artificial hydrothermal vents in the Iheya North field, Okinawa Trough  

NASA Astrophysics Data System (ADS)

In 2010, IODP Expedition 331 was conducted in the Iheya North Field, the Okinawa Trough and drilled several sites in hydrothermally active subseafloor. In addition, during the IODP Expedition 331, four new hydrothermal vents were created. These post-drilling artificial hydrothermal vents provide excellent opportunities to investigate the physical, chemical and microbiological characteristics of the previously unexplored subseafloor hydrothermal fluid reservoirs, and to monitor and estimate how the anthropogenic drilling behaviors affect the deep-sea hydrothermal vent ecosystem. We were very much interested in the difference of hydrothermal fluid chemistry between the natural hydrothermal vents and the artificial hydrothermal vents. The IODP porewater chemistry of the cores pointed to the density-driven stratification of the phase-separated hydrothermal fluids and the natural vent fluids were likely derived only from the shallower vapor-enriched phases. However, the artificial hydrothermal vents had deeper fluid sources in the subseafloor hydrothermal fluid reservoirs composed of vapor-lost (Cl-enriched) phases. The fluids from the artificial hydrothermal vents were sampled by ROV at 5, 12 and 18 months after the IODP expedition. The artificial hydrothermal vent fluids were slightly enriched with Cl as compared to the natural hydrothermal vent fluids. Thus, the artificial hydrothermal vents successfully entrained the previously unexplored subseafloor hydrothermal fluids. The newly created hydrothermal vents also hosted the very quickly grown, enormous chimney structures, of which mineral compositions were highly variable among the vents. However, the quickly grown C0016B and C0016D vent chimneys were found to be typical Kuroko ore even though the chimney growth rates in the artificial vents were extremely faster than those in the natural vents. In addition, the IODP drilling operation not only created new hydrothermal vents by deep drilling but also induced the newly generated diffusing flows by many short drillings in the seafloor where no apparent hydrothermal fluid discharge was observed (e.g., C0013 and C0014). The new widespread diffusing flows altered the habitat condition, and provided post-drilling propagation and colonization of indigenous hydrothermal chemosynthetic animals. Interestingly, the first colonizers were shrimps and polychaeta, which were identified at C0013 and C0016 in 6 months after the IODP expedition, while the most drastic propagation and colonization were conducted by the most predominant chemosynthetic animal species in the Iheya North field, vent crab Shinkaia crosnieri. It appeared at C0014 site (500 m distant from their large colonies) in a year and dominated the new diffusing flow sites. It seems likely that IODP drilling operation and the post-drilling hydrothermal activities would have an impact on increasing biomass production and widespread propagation of hydrothermal vent ecosystem in the Iheya North field.

Takai, K.; Kawagucci, S.; Miyazaki, J.; Watsuji, T.; Ishibashi, J.; Yamamoto, H.; Nozaki, T.; Kashiwabara, T.; Shibuya, T.

2012-12-01

21

Arsenic speciation in shrimp and mussel from the Mid-Atlantic hydrothermal vents  

Microsoft Academic Search

Specimens of shrimp (Rimicaris exoculata) and mussel (Bathymodiolus puteoserpentis) were collected 3500 m below the ocean surface at the hydrothermal vents of the mid-Atlantic Ridge (TAG and Snake Pit sites, respectively). Arsenic, a potentially toxic element, is among the substances emitted by the hydrothermal vents. The hydrothermal vent shrimp, which are known to be a primary consumer of the primary

Erik H. Larsen; Christophe R. Quétel; Riansares Munoz; Aline Fiala-Medioni; Olivier F. X. Donard

1997-01-01

22

Hydrothermal Vent Animals: Distribution and Biology  

Microsoft Academic Search

Hydrothermal vent communities characterized by large clams, mussels, and vestimentiferan worms thrive on chemosynthetic microbial production. There are similarities in the animal distributions at vent communities from 20 degrees S to 46 degrees N on the Mid-Ocean Ridge in the Pacific Ocean and at cold sulfide seeps in the Gulf of Mexico. Vent communities, consisting of at least 16 previously

J. Frederick Grassle

1985-01-01

23

The NeMO Explorer Web Site: Interactive Exploration of a Recent Submarine Eruption and Hydrothermal Vents, Axial Volcano, Juan de Fuca Ridge  

NASA Astrophysics Data System (ADS)

To help visualize the submarine volcanic landscape at NOAA's New Millennium Observatory (NeMO), we have created the NeMO Explorer web site: http://www.pmel.noaa.gov/vents/nemo/explorer.html. This web site takes visitors a mile down beneath the ocean surface to explore Axial Seamount, an active submarine volcano 300 miles off the Oregon coast. We use virtual reality to put visitors in a photorealistic 3-D model of the seafloor that lets them view hydrothermal vents and fresh lava flows as if they were really on the seafloor. At each of six virtual sites there is an animated tour and a 360o panorama in which users can view the volcanic landscape and see biological communities within a spatially accurate context. From the six sites there are hyperlinks to 50 video clips taken by a remotely operated vehicle. Each virtual site concentrates on a different topic, including the dynamics of the 1998 eruption at Axial volcano (Rumbleometer), high-temperature hydrothermal vents (CASM and ASHES), diffuse hydrothermal venting (Marker33), subsurface microbial blooms (The Pit), and the boundary between old and new lavas (Castle vent). In addition to exploring the region geographically, visitors can also explore the web site via geological concepts. The concepts gallery lets you quickly find information about mid-ocean ridges, hydrothermal vents, vent fauna, lava morphology, and more. Of particular interest is an animation of the January 1998 eruption, which shows the rapid inflation (by over 3 m) and draining of the sheet flow. For more info see Fox et al., Nature, v.412, p.727, 2001. This project was funded by NOAA's High Performance Computing and Communication (HPCC) and Vents Programs. Our goal is to present a representative portion of the vast collection of NOAA's multimedia imagery to the public in a way that is easy to use and understand. These data are particularly challenging to present because of their high data rates and low contextual information. The 3-D models create effective context and new video technology allows us to present good quality video at lower data rates. Related curriculum materials for middle- and high-school students are also available from the NeMO web site at http://www.pmel.noaa.gov/vents/nemo/education.html. >http://www.pmel.noaa.gov/vents/nemo/explorer.html

Weiland, C.; Chadwick, W. W.; Embley, R. W.

2001-12-01

24

Modelling of hydrothermal fluid circulation in a heterogeneous medium: Application to the Rainbow Vent site (Mid-Atlantic-Ridge, 36°14N)  

NASA Astrophysics Data System (ADS)

Hydrothermal activity at the axis of mid-ocean ridges is a key driver for energy and matter transfer from the interior of the Earth to the ocean floor. At mid-ocean ridges, seawater penetrates through the permeable young crust, warms at depth and exchanges chemicals with the surrounding rocks. This hot fluid focuses and flows upwards, then is expelled from the crust at hydrothermal vent sites in the form of black or white smokers completed by diffusive emissions. We developed a new numerical tool in the Cast3M software framework to model such hydrothermal circulations. Thermodynamic properties of one-phase pure water were calculated from the IAPWS formulation. This new numerical tool was validated on several test cases of convection in closed-top and open-top boxes. Simulations of hydrothermal circulation in a homogeneous-permeability porous medium also gave results in good agreement with already published simulations. We used this new numerical tool to construct a geometric and physical model configuration of the Rainbow Vent site at 36°14'N on the Mid-Atlantic Ridge. In this presentation, several configurations will be discussed, showing that high temperatures and high mass fluxes measured at the Rainbow site cannot be modelled with hydrothermal circulation in a homogeneous-permeability porous medium. We will show that these high values require the presence of a fault or a preferential pathway right below the venting site. We will propose and discuss a 2-D one-path model that allows us to simulate both high temperatures and high mass fluxes. This modelling of the hydrothermal circulation at the Rainbow site constitutes a first but necessary step to understand the origin of high concentrations of hydrogen issued from this ultramafic-hosted vent field.

Perez, F.; Mügler, C.; Jean-Baptiste, P.; Charlou, J. L.

2012-04-01

25

Trophic regions of a hydrothermal plume dispersing away from an ultramafic-hosted vent-system: Von Damm vent-site, Mid-Cayman Rise  

NASA Astrophysics Data System (ADS)

Abstract Deep-sea ultramafic-hosted <span class="hlt">vent</span> systems have the potential to provide large amounts of metabolic energy to both autotrophic and heterotrophic microorganisms in their dispersing <span class="hlt">hydrothermal</span> plumes. Such <span class="hlt">vent</span>-systems release large quantities of hydrogen and methane to the water column, both of which can be exploited by autotrophic microorganisms. Carbon cycling in these <span class="hlt">hydrothermal</span> plumes may, therefore, have an important influence on open-ocean biogeochemistry. In this study, we investigated an ultramafic-hosted system on the Mid-Cayman Rise, emitting metal-poor and hydrogen sulfide-, methane-, and hydrogen-rich <span class="hlt">hydrothermal</span> fluids. Total organic carbon concentrations in the plume ranged between 42.1 and 51.1 ?M (background = 43.2 ± 0.7 ?M (n = 5)) and near-field plume samples with elevated methane concentrations imply the presence of chemoautotrophic primary production and in particular methanotrophy. In parts of the plume characterized by persistent potential temperature anomalies but lacking elevated methane concentrations, we found elevated organic carbon concentrations of up to 51.1 ?M, most likely resulting from the presence of heterotrophic communities, their extracellular products and <span class="hlt">vent</span> larvae. Elevated carbon concentrations up to 47.4 ?M were detected even in far-field plume samples. Within the Von Damm <span class="hlt">hydrothermal</span> plume, we have used our data to hypothesize a microbial food web in which chemoautotrophy supports a heterotrophic community of microorganisms. Such an active microbial food web would provide a source of labile organic carbon to the deep ocean that should be considered in any future studies evaluating sources and sinks of carbon from <span class="hlt">hydrothermal</span> <span class="hlt">venting</span> to the deep ocean.</p> <div class="credits"> <p class="dwt_author">Bennett, Sarah A.; Coleman, Max; Huber, Julie A.; Reddington, Emily; Kinsey, James C.; McIntyre, Cameron; Seewald, Jeffrey S.; German, Christopher R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-02-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">26</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.sb-roscoff.fr/Ecchis/pdf/07-Cravo-EnvInt.pdf"> <span id="translatedtitle">Metals in the shell of Bathymodiolus azoricus from a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span> on the Mid-Atlantic Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Specimens of the mussel Bathymodiolus azoricus were collected from Menez Gwen, a relatively shallow (850 m) <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field on the Mid-Atlantic Ridge. Each bivalve shell (n=21) was individually cleaned by selective chemical. The residual crystal matrix of each shell was individually analysed for the concentrations of the minor elements magnesium and strontium and the trace elements iron, manganese, copper and</p> <div class="credits"> <p class="dwt_author">A. Cravo; P. Foster; C. Almeida; R. P. Cosson; M. J. Bebianno</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">27</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2007AGUFM.V34B..04P"> <span id="translatedtitle">Volatile Chemistry at Lau Basin <span class="hlt">Hydrothermal</span> <span class="hlt">Sites</span>: Basin-Wide Trends of Slab Carbonate Influence and Suggestions of Abiotic Methane Oxidation at the Mariner <span class="hlt">Vent</span> <span class="hlt">Site</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Lau Basin is actively spreading along three major spreading centers: the Central Lau Spreading Center (CLSC) in the north, the Eastern Lau Spreading Center (ELSC), and the Valu Fa Ridge (VFR) to the south. A southward progression along these spreading centers reveals decreasing spreading rates, decreasing distance to the arc, and a corresponding increase in the influence of the subducted Pacific plate slab (1, 2). Analysis of the d13CO2 and He data from volatile samples collected during a 2005 expedition to six <span class="hlt">hydrothermal</span> <span class="hlt">sites</span> along the ELSC and VFR reveals a systematic and continuous relationship between latitude (distance from the arc) and the arc-derived component of the signal. This smooth and linear transition from arc-like <span class="hlt">hydrothermal</span> volatiles in the south to more MORB-like <span class="hlt">hydrothermal</span> volatiles in the north contrasts the interpretation from the dredged geologic record that suggests an extremely sharp andesite-basalt transition occurring along the southern portion of the ESLC (3). The Mariner <span class="hlt">vent</span> <span class="hlt">site</span>, the southernmost high-temperature <span class="hlt">site</span> visited in 2005, exhibits an arc-influenced volatile chemistry that is different from the other Lau Basin <span class="hlt">sites</span>. The ESLC and northern VFR <span class="hlt">vents</span> are characterized by CO2 concentrations ranging from 1-12 mmol/kg while the Mariner <span class="hlt">site</span> has higher CO2 values, up to 60 mmol/kg. The opposite trend is seen in the methane concentrations as the northern <span class="hlt">vents</span> range from 25-55 ?mol/kg while Mariner methane values are much lower, at 5-7 ?mol/kg. Isotopic results also illustrate the unique chemistry of the Mariner <span class="hlt">site</span>: d13CO2 values are in the typical MOR-<span class="hlt">hydrothermal</span> range of -7 to -4 per mil at northern <span class="hlt">vents</span> and near 0 per mil at Mariner, and d13CH4 values are in the typical MOR-<span class="hlt">hydrothermal</span> range of - 25 to -20 per mil at northern <span class="hlt">vents</span>, and highly enriched, -7 to +0.7 per mil at Mariner. The CO2/3He ratio and the d13CO2 values at Mariner suggest that 80 percent of the CO2 at Mariner is sourced from carbonates, presumably from authigenically formed carbonates in the downgoing slab. The low CH4 concentrations and uniquely enriched d13CH4 signatures at Mariner are hypothesized to be the result of abiotic methane oxidation at <span class="hlt">hydrothermal</span> temperatures. 1. Jacobs, A.M., A. J. Harding, G. M. Kent, Earth and Planetary Science Letters 259, 239 (2007). 2. Martinez, F., B. Taylor, E. T. Baker, J. A. Resing, S. L. Walker, Earth and Planetary Science Letters 245, 655 (2006). 3. Bezos, A., et al., Eos, Transactions, American Geophysical Union 86, Abstract V41C (2005).</p> <div class="credits"> <p class="dwt_author">Proskurowski, G.; Seewald, J. S.; Reeves, E.; McCollom, T. M.; Lupton, J.; Sylva, S.; Tivey, M. K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">28</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3250503"> <span id="translatedtitle">Antarctic Marine Biodiversity and Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The diversity of many marine benthic groups is unlike that of most other taxa. Rather than declining from the tropics to the poles, much of the benthos shows high diversity in the Southern Ocean. Moreover, many species are unique to the Antarctic region. Recent work has shown that this is also true of the communities of Antarctic deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. <span class="hlt">Vent</span> ecosystems have been documented from many <span class="hlt">sites</span> across the globe, associated with the thermally and chemically variable habitats found around these, typically high temperature, streams that are rich in reduced compounds and polymetallic sulphides. The animal communities of the East Scotia Ridge <span class="hlt">vent</span> ecosystems are very different to those elsewhere, though the microbiota, which form the basis of <span class="hlt">vent</span> food webs, show less differentiation. Much of the biological significance of deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> lies in their biodiversity, the diverse biochemistry of their bacteria, the remarkable symbioses among many of the marine animals and these bacteria, and the prospects that investigations of these systems hold for understanding the conditions that may have led to the first appearance of life. The discovery of diverse and unusual Antarctic <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystems provides opportunities for new understanding in these fields. Moreover, the Antarctic <span class="hlt">vents</span> south of 60°S benefit from automatic conservation under the Convention on the Conservation of Antarctic Marine Living Resources and the Antarctic Treaty. Other deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> located in international waters are not protected and may be threatened by growing interests in deep-sea mining.</p> <div class="credits"> <p class="dwt_author">Chown, Steven L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">29</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=91328"> <span id="translatedtitle">Rapid Microbial Production of Filamentous Sulfur Mats at <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span>†</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">During recent oceanographic cruises to Pacific <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> (9°N and the Guaymas Basin), the rapid microbial formation of filamentous sulfur mats by a new chemoautotrophic, hydrogen sulfide-oxidizing bacterium was documented in both in situ and shipboard experiments. Observations suggest that formation of these sulfur mats may be a factor in the initial colonization of <span class="hlt">hydrothermal</span> surfaces by macrofaunal Alvinella worms. This novel metabolic capability, previously shown to be carried out by a coastal strain in H2S continuous-flow reactors, may be an important, heretofore unconsidered, source of microbial organic matter production at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</p> <div class="credits"> <p class="dwt_author">Taylor, Craig D.; Wirsen, Carl O.; Gaill, Francoise</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">30</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/53328884"> <span id="translatedtitle">Light at deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We usually think of the bottom of the sea as a dark environment, lit only by flashes of bioluminescent light. Discovery of light associated with geothermal processes at deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> forces us to qualify our textbook descriptions of the seafloor as a uniformly dark environment. While a very dim glow emitted from high temperature (350°) <span class="hlt">vents</span> (black smokers)</p> <div class="credits"> <p class="dwt_author">Cindy Lee Van Dover; J. R. Cann; Colleen Cavanaugh; Steven Chamberlain; John R. Delaney; David Janecky; Johannes Imhoff; J. Anthony Tyson</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">31</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/2150322"> <span id="translatedtitle">Fine-Scale Three-Dimensional Mapping of a Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> <span class="hlt">Site</span> Using the Jason ROV System</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Using precise navigation, a computer-controlled remotely operated vehicle, and a variety of optical and acoustic imaging sensors, we created the most precise three-dimensional renderings ever made of an active <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field at a depth of 2400 meters on the deep sea floor. Data products included electronic and film photographs as well as three-dimensional sonar scans. We used these to</p> <div class="credits"> <p class="dwt_author">Dana R. Yoerger; Deborah S. Kelley; John R. Delaney</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">32</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41388824"> <span id="translatedtitle">Biological factors influencing tissue compartmentalization of trace metals in the deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> bivalve Bathymodiolus azoricus at geochemically distinct <span class="hlt">vent</span> <span class="hlt">sites</span> of the Mid-Atlantic Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In this study, we investigated on concentrations of trace metals (Al,\\u000a Cd, Mn, Co, and Hg) in the <span class="hlt">hydrothermal</span> bivalve Bathymodiolus azoricus,\\u000a a dominant species at most <span class="hlt">vent</span> <span class="hlt">sites</span> along the Mid-Atlantic Ridge\\u000a (MAR), and in its endosymbiont bacteria and commensal parasite\\u000a Branchipolynoe seepensis. Comparison of our results with data from the\\u000a literature on nonhydrothermal bivalves suggests lack of ``extreme{''}</p> <div class="credits"> <p class="dwt_author">E Kadar; RS Santos; Jonathan J. Powell</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">33</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24882018"> <span id="translatedtitle"><span class="hlt">Site</span>-related differences in gene expression and bacterial densities in the mussel Bathymodiolus azoricus from the Menez Gwen and Lucky Strike deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus is a symbiont bearing bivalve that is found in great abundance at the Menez Gwen and Lucky Strike <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> and in close vicinity of the Azores region near the Mid-Atlantic Ridge (MAR). The physiological relationships that <span class="hlt">vent</span> mussels have developed with their physical and chemical environments are likely to influence global gene expression profiles providing thus the means to investigate distinct biological markers predicting the origin of Bathymodiolus sp. irrespectively of their geographical localization. Differences found at gene expression levels, and between fluorescence in situ hybridization (FISH) and 16S rRNA amplicon sequencing results provided experimental evidence for the distinction of both Menez Gwen and Lucky Strike <span class="hlt">vent</span> mussel individuals based on bacterial and <span class="hlt">vent</span> mussel gene expression signatures and on the constitutive distribution and relative abundance of endosymbiotic bacteria within gill tissues. Our results confirmed the presence of methanotroph endosymbionts in Menez Gwen <span class="hlt">vent</span> mussels whereas Lucky Strike specimens seem to harbor a different bacterial morphotype when a methane monooxygenase gene specific probe was used. No qualitative differences could be visualized between Menez Gwen and Lucky Strike individuals when tested with a sulfur-oxidizing-related probe. Quantitative PCR (qPCR) studies revealed different gene expression profiles in both Menez Gwen and Lucky Strike mussel gill tissues for the immune genes selected. Genes encoding transcription factors presented noticeably low levels of fold expression whether in Menez Gwen or Lucky Strike animals whereas the genes encoding effector molecules appeared to have higher levels expression in gill tissues from Menez Gwen animals. The peptidoglycan recognition molecule encoding gene, PGRP, presented the highest level of transcriptional activity among the genes analyzed in Menez Gwen mussel gill tissues, seconded by carcinolectin and thus denoting the relevance of immune recognition molecules in early stage of the immune responses onset. Genes regarded as encoding molecules involved in signaling pathways were consistently expressed in both Menez Gwen and Lucky Strike mussel gill tissues. Remarkably, the immunity-related GTPase encoding gene demonstrated, in Lucky Strike samples, the highest level of expression among the signaling molecule encoding genes tested when expressions levels were compared between Menez Gwen and Lucky Strike animals. A differential expression analysis of bacterial genes between Menez Gwen and Lucky Strike mussels indicated a clear expression signature in the latter animal gill tissues. The bacterial community structure ensued from the 16S rRNA sequencing analyses pointed at an unpredicted conservation of endosymbiont bacterial loads between Menez Gwen and Lucky Strike samples. Taken together, our results support the hypothesis that B. azoricus exhibits different transcriptional statuses while living in distinct <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> may result in distinct gene expressions because of physico-chemical and/or symbiont densities differences. PMID:24882018</p> <div class="credits"> <p class="dwt_author">Bettencourt, Raul; Rodrigues, Mónica; Barros, Inês; Cerqueira, Teresa; Freitas, Cátia; Costa, Valentina; Pinheiro, Miguel; Egas, Conceição; Santos, Ricardo Serrão</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">34</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/21833083"> <span id="translatedtitle">Hydrogen is an energy source for <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> symbioses.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The discovery of deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in 1977 revolutionized our understanding of the energy sources that fuel primary productivity on Earth. <span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> ecosystems are dominated by animals that live in symbiosis with chemosynthetic bacteria. So far, only two energy sources have been shown to power chemosynthetic symbioses: reduced sulphur compounds and methane. Using metagenome sequencing, single-gene fluorescence in situ hybridization, immunohistochemistry, shipboard incubations and in situ mass spectrometry, we show here that the symbionts of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus from the Mid-Atlantic Ridge use hydrogen to power primary production. In addition, we show that the symbionts of Bathymodiolus mussels from Pacific <span class="hlt">vents</span> have hupL, the key gene for hydrogen oxidation. Furthermore, the symbionts of other <span class="hlt">vent</span> animals such as the tubeworm Riftia pachyptila and the shrimp Rimicaris exoculata also have hupL. We propose that the ability to use hydrogen as an energy source is widespread in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> symbioses, particularly at <span class="hlt">sites</span> where hydrogen is abundant. PMID:21833083</p> <div class="credits"> <p class="dwt_author">Petersen, Jillian M; Zielinski, Frank U; Pape, Thomas; Seifert, Richard; Moraru, Cristina; Amann, Rudolf; Hourdez, Stephane; Girguis, Peter R; Wankel, Scott D; Barbe, Valerie; Pelletier, Eric; Fink, Dennis; Borowski, Christian; Bach, Wolfgang; Dubilier, Nicole</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-08-11</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">35</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008AGUFM.V41B2076G"> <span id="translatedtitle">Bacterial Diets of Primary Consumers at <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Chemical energy produced by mixing <span class="hlt">hydrothermal</span> fluids and seawater supports dense biological communities on mid-ocean ridges. The base of the food web at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> is formed by chemolithoautotrophic bacteria that use the energy from the oxidation of reduced chemicals to fix inorganic carbon into simple sugars. With the exception of a few species that have chemolithoautotropic bacterial symbionts, most of the <span class="hlt">vent</span>-endemic macrofauna are heterotrophs that feed on free-living bacteria, protists, and other invertebrates. The most abundant and diverse group of primary consumers in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> communities belong to the Gastropoda, particularly the patellomorph limpets. Gastropod densities can be as high as 2000 individuals m-2, and there can be as many as 13 species of gastropods in a single aggregation of the siboglinid tubeworm Riftia pachyptila and more than 40 species along the East Pacific Rise. Some gastropods are ubiquitous and others are found in specific microhabitats, stages of succession, or associated with different foundation species. To determine the mechanisms of species coexistence (e.g. resource partitioning or competition) among <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> primary consumers and to track the flow of energy in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> communities, we employed molecular genetic techniques to identify the gut contents of four species of co-occurring <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> gastropods, Eulepetopsis vitrea, Lepetodrilus elevatus, Lepetodrilus ovalis and Lepetodrilus pustulosus, collected from a single diffuse-flow <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span> on the East Pacific Rise. Unique haplotypes of the 16S gene that fell among the epsilon-proteobacteria were found in the guts of every species, and two species had gut contents that were similar only to epsilon-proteobacteria. Two species had gut contents that also included haplotypes that clustered with delta-proteobacteria, and one species had gut contents that clustered with alpha- proteobacteria. Differences in the diets of these four <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> gastropods may reflect microhabitat conditions where these species typically occur or where they were located at the time of the collection. Results from this work provide insights to the "bottom-up" regulation of primary consumers and tracking chemical fluxes through biological communities at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</p> <div class="credits"> <p class="dwt_author">Govenar, B.; Shank, T. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">36</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://edition.cnn.com/2001/TECH/science/07/11/hydrothermal.vents/"> <span id="translatedtitle">New Type of <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> Found</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://nsdl.org/nsdl_dds/services/ddsws1-1/service_explorer.jsp">NSDL National Science Digital Library</a></p> <p class="result-summary">This CNN news article discusses the discovery of a new class of <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in the mid-Atlantic Ocean, called the Lost City, formed by heat generated when seawater reacts with mantle rocks rather than by volcanic activity. The article also notes the importance of the discovery to microbiologists, as some of these new <span class="hlt">vents</span> were inhabited by single-cell organisms called thermophiles. Links to other CNN.com articles and resources are provided as well.</p> <div class="credits"> <p class="dwt_author">Walker, Alex</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-07-07</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">37</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011EOSTr..92..169R"> <span id="translatedtitle">Sonar images <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in seafloor observatory</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> plumes <span class="hlt">venting</span> from black smokers and diffuse flow discharging from the surrounding area of the seafloor are important as agents of transfer of heat, chemicals, and biological material from the crust into the ocean in quantitatively significant amounts [Elderfield and Schultz, 1996]. An unprecedented time series of three-dimensional (3-D) volume images of plumes rising tens of meters from black smoker <span class="hlt">vents</span> and of concurrent 2-D maps of diffuse flow discharging from surrounding areas of the seafloor illuminates the turbulent behavior of <span class="hlt">hydrothermal</span> fluid transfer into the ocean (see Figure 1).</p> <div class="credits"> <p class="dwt_author">Rona, Peter; Light, Russ</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">38</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17291587"> <span id="translatedtitle">Metals in the shell of Bathymodiolus azoricus from a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span> on the Mid-Atlantic Ridge.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Specimens of the mussel Bathymodiolus azoricus were collected from Menez Gwen, a relatively shallow (850 m) <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field on the Mid-Atlantic Ridge. Each bivalve shell (n = 21) was individually cleaned by selective chemical. The residual crystal matrix of each shell was individually analysed for the concentrations of the minor elements magnesium and strontium and the trace elements iron, manganese, copper and zinc. The chemical composition of the crystal matrix is unusual. B. azoricus is identified as a species having one of the most strontium impoverished shells amongst the marine molluscs. For a bimineral species the magnesium concentration is also extraordinary low. Despite originating from a trace metal rich environment; the metal concentrations in the shells were exceptionally low. Mean concentrations of iron, manganese, copper and zinc were 20.6, 3.7, 0.6 and 9.4 microg g(-1) respectively. Minor and trace element concentrations exhibited a marked intra-population variability. Copper concentrations increased and iron and zinc concentrations decreased with increasing shell weight. Due to its insensitivity to the high environmental levels of trace elements and the variability in intra-population concentrations induced by shell weight the crystal matrix of the shell of B. azoricus has little potential for use in environmental trace metal monitoring in areas contiguous to deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. PMID:17291587</p> <div class="credits"> <p class="dwt_author">Cravo, A; Foster, P; Almeida, C; Company, R; Cosson, R P; Bebianno, M J</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">39</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004LPI....35.2055C"> <span id="translatedtitle">Optical Detection of Organic Chemical Biosignatures at <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We've developed a non-contact optical instrument for the rapid detection of organic chemical biosignatures. This tool is suitable for use on dry land, shallow aqueous, deep marine or ice environments. Here we report results from its deployment at <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> in the Pacific Ocean.</p> <div class="credits"> <p class="dwt_author">Conrad, P. G.; Lane, A. L.; Bhartia, R.; Hug, W. H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">40</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1993Geo....21..499T"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> in Lake Tanganyika, East African, Rift system</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Sublacustrine <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> with associated massive sulfides were discovered during April 1987 at Pemba and Cape Banza on the Zaire side of the northern basin of Lake Tanganyika, East African Rift system. New investigations by a team of ten scuba divers during the multinational (France, Zaire, Germany, and Burundi) TANGANYDRO expedition (August-October 1991) found <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> down to a depth of 46 m along north-trending active faults bounding the Tanganyika rift on the western side. Temperatures from 53 to 103 °C were measured in <span class="hlt">hydrothermal</span> fluids and sediments. Veins of massive sulfides 1-10 cm thick (pyrite and marcasite banding) were found associated with <span class="hlt">vents</span> at the Pemba <span class="hlt">site</span>. At Cape Banza,active <span class="hlt">vents</span> are characterized by 1-70-cm-high aragonite chimneys, and there are microcrystalline pyrite coatings on the walls of <span class="hlt">hydrothermal</span> pipes. <span class="hlt">Hydrothermal</span> fluid end members show distinctive compositions at the two <span class="hlt">sites</span>. The Pemba end member is a NaHCO3-enriched fluid similar to the NaHCO3 thermal fluids from lakes Magadi and Bogoria in the eastern branch off the rift. The Cape Banza end member is a solution enriched in NaCl. Such brines may have a deep-seated basement origin, as do the Uvinza NaCl brines on the eastern flank of the Tanganyika basin. Geothermometric calculations have yielded temperatures of fluid-rock interaction off 219 and 179 °C in the Pemba and Cape Banza systems, respectively. Abundant white or reddish-brown microbial colonies resembling Beggiatoa</em> mats were found surrounding the active <span class="hlt">vents</span>. Thermal fluid circulation is permitted by opening of cracks related to 130 °N normal-dextral faults that intersect the north- south major rift trend. The source of heat for such <span class="hlt">hydrothermal</span> systems may relate to the existence of magmatic bodies under the rift, which is suggested by the isotopic composition of carbon dioxide released at Pemba and Cape Banza.</p> <div class="credits"> <p class="dwt_author">Tiercelin, Jean-Jacques; Pflumio, Catherine; Castrec, Maryse; Boulégue, Jacques; Gente, Pascal; Rolet, Joël; Coussement, Christophe; Stetter, Karl O.; Huber, Robert; Buku, Sony; Mifundu, Wafula</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-06-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a 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href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_4");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">41</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010AGUFMNS33A..02N"> <span id="translatedtitle">Evidence for <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> as "Biogeobatteries" (Invited)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> are unique systems that play an important role in oceanic biogeochemical cycles. As chemically reduced <span class="hlt">hydrothermal</span> fluid mixes with cold oxic seawater, minerals precipitate out of solution resulting in chimney structures composed largely of metal sulfides and anhydrite. Pyrite, which is a natural semi-conductor, is the primary sulfide mineral, but other minerals within chimneys are also conductive (e.g. chalcopyrite, wurtzite, and some iron oxides). Sulfide chimneys are also known to host an extensive endolithic microbial community. Accordingly, submarine <span class="hlt">hydrothermal</span> systems appear to be examples of biogeobatteries, wherein conductive mineral assemblages span naturally occuring redox gradients and enable anaerobic microbes to access oxygen as an oxidant via extracellular electron transfer (or EET). To test this hypothesis, we ran a series of electrochemical laboratory experiments in which pyrite was used as an anode (in a vessel flushed with <span class="hlt">hydrothermal</span>-like fluid). When placed in continuity with a carbon fiber cathode, pyrite was found to accept and conduct electrons from both abiotic and biological processes (microbial EET). Specifically, electrical current increased 4-fold (5 nA/m2 to 20 nA/m2) in response to inoculation with a slurry prepared from a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> sample. Inspection of the pyrite anode with SEM revealed ubiquitous coverage by microbes. DNA was extracted from the anodes and the inoculum, and was subjected to pyrosequencing to examine prokaryotic diversity. These data suggest that key microbial phylotypes were enriched upon the pyrite, implicating them in EET. In addition, we deployed an in situ experiment based on microbial fuel cell architecture with a graphite anode inserted into a <span class="hlt">vent</span> wall coupled to a carbon fiber cathode outside the <span class="hlt">vent</span>. We observed current production over the course of one year, implying microbial EET in situ. Via pyrosequencing, we observed that the microbial community on the anode was significantly enriched in gammaproteobacteria (with respect to the community on an inert substrate deployed in the same <span class="hlt">vent</span>, which was dominated by epsilonproteobacteria). The observation of electrical current and the enrichment of distinct microbial communities in both laboratory and in situ experiments provide evidence that <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> enable microbes capable of EET to access molecular oxygen in the surrounding seawater as an oxidant. This geochemical and microbial phenomenon may influence the chemistry and mineralogy of <span class="hlt">vent</span> systems, resulting in localized variations in pH that can influence metal mobilization on a global scale.</p> <div class="credits"> <p class="dwt_author">Nielsen, M. E.; Girguis, P. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">42</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/46796877"> <span id="translatedtitle">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> animals seek cool fluids in a highly variable thermal environment</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The thermal characteristics of an organism's environment affect a multitude of parameters, from biochemical to evolutionary processes. <span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> on mid-ocean ridges are created when warm <span class="hlt">hydrothermal</span> fluids are ejected from the seafloor and mixed with cold bottom seawater; many animals thrive along these steep temperature and chemical gradients. Two-dimensional temperature maps at <span class="hlt">vent</span> <span class="hlt">sites</span> have demonstrated order of magnitude</p> <div class="credits"> <p class="dwt_author">Raymond W Lee; Verena Tunnicliffe; Miles D Lamare; Amanda E Bates</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">43</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/16199029"> <span id="translatedtitle">Biological factors influencing tissue compartmentalization of trace metals in the deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> bivalve Bathymodiolus azoricus at geochemically distinct <span class="hlt">vent</span> <span class="hlt">sites</span> of the Mid-Atlantic Ridge.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">In this study, we investigated on concentrations of trace metals (Al, Cd, Mn, Co, and Hg) in the <span class="hlt">hydrothermal</span> bivalve Bathymodiolus azoricus, a dominant species at most <span class="hlt">vent</span> <span class="hlt">sites</span> along the Mid-Atlantic Ridge (MAR), and in its endosymbiont bacteria and commensal parasite Branchipolynoe seepensis. Comparison of our results with data from the literature on non-<span class="hlt">hydrothermal</span> bivalves suggests lack of "extreme" uptake of trace metals by B. azoricus, except for Hg concentration which exceeded manyfold previously reported values. Mussels collected from three geochemically distinct <span class="hlt">vent</span> <span class="hlt">sites</span>, Menez Gwen, Lucky Strike, and Rainbow, along the MAR showed significant differences in tissue concentration of metals. Proportionality of metals in soft tissues of mussels reflected variation of water chemistry at different <span class="hlt">vents</span>, which in turn conserved the order of trace metal prevalence in undiluted fluids. There were significant tissue-specific differences in trace metal compartmentalization for all metals investigated. Byssus thread contained the highest metal concentration among examined tissues, and thus it is suggested to be an important detoxification route. Size-dependent differences in metal concentrations were detected only for Hg, revealing a general trend of small mussels accumulating more metal than big mussels. Endosymbiont bacteria are shown to exclusively sequester Al from the host gill and contribute to removal of other toxic metals in mussels from Menez Gwen. The commensal parasite present in all mussels from Lucky Strike had higher tissue concentrations of Mn, Al, and Co than the host gill, unlike Cd and Hg which were considerably lower in the former, and thus its role in detoxification remains unclear. Bioaccumulation potential of <span class="hlt">vent</span> bivalves and associated organisms are quantified as concentration factors and compared to make inferences on the putative role of the endosymbiont bacteria and the commensal parasite in detoxification of trace metals. PMID:16199029</p> <div class="credits"> <p class="dwt_author">Kádár, Enikõ; Santos, Ricardo S; Powell, Jonathan J</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">44</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013BGD....10.2013B"> <span id="translatedtitle">Differential gene expression in the mussel Bathymodiolus azoricus from the Menez Gwen and Lucky Strike deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus is a symbiont bearing bivalve that is found in great abundance at the Menez Gwen and Lucky Strike <span class="hlt">vent</span> <span class="hlt">sites</span> and in close vicinity off the Azores region near the Mid-Atlantic Ridge (MAR). The distinct relationships that <span class="hlt">vent</span> mussels have developed with their physical and chemical environments are likely reflected in global gene expression profiles providing thus a means to distinguish geographically distinct <span class="hlt">vent</span> mussels on the basis of gene expression studies, fluorescence in situ hybridization (FISH) experiments and 16S rRNA amplicon sequencing, to assess the natural expression of bacterial genes and <span class="hlt">vent</span> mussel immune genes and the constitutive distribution and relative abundance of endosymbiotic bacteria within gill tissues. Our results confirmed the presence of methanotroph-related endosymbionts in Menez Gwen <span class="hlt">vent</span> mussels whereas Lucky Strike specimens seem to harbor a different bacterial morphotype when a methane monooxygenase gene specific probe was used. No qualitative differences could be visualized between Menez Gwen and Lucky Strike individuals when tested with sulfur-oxidizing-related nucleic-acid probe. Quantitative PCR (qPCR) studies revealed varied gene expression profiles in both Menez Gwen and Lucky Strike mussel gill tissues for the immune genes selected. Genes encoding transcription factors presented noticeably low levels of fold expression whether in MG or LS animals whereas the genes encoding effector molecules appeared to have higher levels expression in MG gill tissues. The peptidoglycan recognition molecule, encoding gene, PGRP presented the highest level of transcriptional activity among the genes analyzed in MG gill tissues, seconded by carcinolectin and thus denoting the relevance of immune recognition molecules in early stage of the immune responses onset. Genes regarded as encoding molecules involved in signaling pathways were consistently expressed in both MG and LS gill tissues. Remarkably, the immunity-related GTPase encoding gene demonstrated in LS samples, the highest level of expression among the signaling molecule encoding genes tested when expressions levels were compared between MG and LG animals. A differential expression analysis of bacterial genes between MG and LS indicated a clear expression signature in LS gill tissues. The bacterial community structure ensued from the 16S rRNA sequencing analyses pointed at a unpredicted conservation of endosymbiont bacterial loads between MG and LS samples. Taken together, our results support the premise that Bathymodiolus azoricus exhibits different transcriptional statuses depending on which <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span> it is collected from and within the same collection <span class="hlt">site</span> while exhibiting differential levels of expression of genes corresponding to different immune functional categories. The present study represents a first attempt to characterize gene expression signatures in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> animals issued from distinct deep-sea environmental <span class="hlt">sites</span> based on immune and bacterial genes expressions.</p> <div class="credits"> <p class="dwt_author">Bettencourt, R.; Rodrigues, M. I.; Barros, I.; Cerqueira, T.; Freitas, C.; Costa, V.; Pinheiro, M.; Egas, C.; Santos, R. S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-02-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">45</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=https://amser.org/index.php?P=AMSER--ResourceFrame&resourceId=11308"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> system unlike any seen before found in Atlantic</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://nsdl.org/nsdl_dds/services/ddsws1-1/service_explorer.jsp">NSDL National Science Digital Library</a></p> <p class="result-summary">This web page is a press release form the University of Washington relating that a team of scientists led by Deborah Kelly, on Dec. 4 2000, discovered a new <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> system that has been named �The Lost City�. This unique <span class="hlt">hydrothermal</span> field is located on an undersea mountain in the Atlantic Ocean and contains towers reaching180 feet above the sea floor composed of silica and carbonate minerals. This is more than 100 feet taller than the average <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> previously observed which are composed of iron and sulfur-based minerals. The web <span class="hlt">site</span> has high-resolution images of these unique underwater features and has links to the investigators that participated in the discovery.</p> <div class="credits"> <p class="dwt_author">Hines, Sandra; Meredith, Dennis; Clark, Cindy; Dybas, Cheryl; University Of Washington, Office O.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">46</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40204213"> <span id="translatedtitle">Vacuolate-attached filaments: highly productive Ridgeia piscesae epibionts at the Juan de Fuca <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Vacuolate sulfur bacteria with high morphological similarity to vacuolate-attached filaments previously described from shallow\\u000a <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> (White Point, CA) were found at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. These filamentous bacteria grow in dense mats\\u000a that cover surfaces and potentially provide a significant source of organic carbon where they occur. Vacuolate-attached filaments\\u000a were collected near <span class="hlt">vents</span> at the Clam Bed <span class="hlt">site</span> of the</p> <div class="credits"> <p class="dwt_author">Karen M. KalanetraDouglas; Douglas C. Nelson</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">47</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012EGUGA..14.3504M"> <span id="translatedtitle">The use of photo-mosaics, bathymetry and sensor data into geographic information system for <span class="hlt">site</span> description and faunal distribution analysis at the Menez Gwen <span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Menez Gwen <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> is located on the Mid-Atlantic Ridge at a depth of about 800m. Although it has been the focus of several expeditions and studies, the <span class="hlt">sites</span> of active <span class="hlt">venting</span> at Menez Gwen are still under described, and it is not possible to get a global picture of the <span class="hlt">sites</span> from the published data. Exploration of deep-sea environments is commonly performed using remotely operated vehicles (ROV) equipped with sensors, cameras and powerful lights. But strong attenuation of light in the deep-sea constrains visual surveys to be carried out from a few meters only above the seafloor, thus limiting the extent of the field of view. Moreover, ROV-mounted positioning systems usually lack accuracy and cannot be relied on for accurate relative positioning of sensor measurements, samplings, and features of interest. Such limitations are hindrances for many applications. In particular, <span class="hlt">site</span> description or mapping of deep-sea benthic fauna over an area of study usually requires lengthy surveys, and reliability of navigation data becomes a major issue. Also, studying small-scale spatial variations of a physicochemical parameter needs positions of sensor measurements or samplings to be known precisely. To overcome this problem, maps of the seafloor can be generated in the form of geo-referenced video- or photo-mosaics. Mosaics are constructed by assembling overlapping images together into a larger image of the scene. To reduce the effects of drift in the navigation data, the construction of the mosaics uses robust feature detection and mapping capabilities to precisely relate consecutive images together. After geo-referencing in a Geographic Information System (GIS), points of measurements and sampling can be accurately pinpointed onto the mosaics to allow for spatial analyses. During cruise M82/3 to the Menez Gwen <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> system, high-resolution photo-mosaics of several <span class="hlt">sites</span> of <span class="hlt">hydrothermal</span> activity were constructed and geo-referenced into GIS systems. The mosaics, together with high-resolution ship-borne bathymetry, allowed unravelling the layout and morphology of the system at different scales. Through GIS analyses, the distribution of the faunal communities in relation to the fluid emission points was mapped and sensor data were integrated to allow describing the spatial variation of water temperature based on CTD measurements. Results include calculation of mussel beds surfaces and inferred estimates of biomass of Bathymodiolus azoricus. Acknowledgements: This work is supported by the European Commission under the EU Framework 7 funded Marie Curie Initial Training Network (ITN) SENSEnet (contract n°237868), and funded through DFG Research Center / Excellence Cluster "The Ocean in the Earth System".</p> <div class="credits"> <p class="dwt_author">Marcon, Y.; Sahling, H.; Bohrmann, G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">48</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ntis.gov/search/product.aspx?ABBR=ADA489201"> <span id="translatedtitle">Spatial and Temporal Population Genetics at Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> Along the East Pacific Rise and Galapagos Rift.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ntis.gov/search/index.aspx">National Technical Information Service (NTIS)</a></p> <p class="result-summary">Ecological processes at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> on fast- spreading mid-ocean ridges are punctuated by frequent physical disturbance. Larval dispersal among disjunct <span class="hlt">vent</span> <span class="hlt">sites</span> facilitates the persistence of sessile invertebrate species in these geolog...</p> <div class="credits"> <p class="dwt_author">A. J. Fusaro</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">49</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008E%26PSL.269...17J"> <span id="translatedtitle">Zinc stable isotopes in seafloor <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fluids and chimneys</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Many of the heaviest and lightest natural zinc (Zn) isotope ratios have been discovered in <span class="hlt">hydrothermal</span> ore deposits. However, the processes responsible for fractionating Zn isotopes in <span class="hlt">hydrothermal</span> systems are poorly understood. In order to better assess the total range of Zn isotopes in <span class="hlt">hydrothermal</span> systems and to understand the factors which are responsible for this isotopic fractionation, we have measured Zn isotopes in seafloor <span class="hlt">hydrothermal</span> fluids from numerous <span class="hlt">vents</span> at 9-10°N and 21°N on the East Pacific Rise (EPR), the TAG <span class="hlt">hydrothermal</span> field on the Mid-Atlantic Ridge, and in the Guaymas Basin. Fluid ?66Zn values measured at these <span class="hlt">sites</span> range from + 0.00‰ to + 1.04‰. Of the many physical and chemical parameters examined, only temperature was found to correlate with fluid ?66Zn values. Lower temperature fluids (< 250 °C) had both heavier and more variable ?66Zn values compared to higher temperature fluids from the same <span class="hlt">hydrothermal</span> fields. We suggest that subsurface cooling of <span class="hlt">hydrothermal</span> fluids leads to precipitation of isotopically light sphalerite (Zn sulfide), and that this process is a primary cause of Zn isotope variation in <span class="hlt">hydrothermal</span> fluids. Thermodynamic calculations carried out to determine saturation state of sphalerite in the <span class="hlt">vent</span> fluids support this hypothesis with isotopically heaviest Zn found in fluids that were calculated to be saturated with respect to sphalerite. We have also measured Zn isotopes in chimney sulfides recovered from a high-temperature (383 °C) and a low-temperature (203 °C) <span class="hlt">vent</span> at 9-10°N on the EPR and, in both cases, found that the ?66Zn of chimney minerals was lighter or similar to the fluid ?66Zn. The first measurements of Zn isotopes in <span class="hlt">hydrothermal</span> fluids have revealed large variations in <span class="hlt">hydrothermal</span> fluid ?66Zn, and suggest that subsurface Zn sulfide precipitation is a primary factor in causing variations in fluid ?66Zn. By understanding how chemical processes that occur beneath the seafloor affect <span class="hlt">hydrothermal</span> fluid ?66Zn, Zn isotopes may be used as a tracer for studying <span class="hlt">hydrothermal</span> processes.</p> <div class="credits"> <p class="dwt_author">John, Seth G.; Rouxel, Olivier J.; Craddock, Paul R.; Engwall, Alison M.; Boyle, Edward A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">50</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003AGUFMOS32A0231R"> <span id="translatedtitle">High-Resolution Photo-Mosaicing of the Rosebud <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> <span class="hlt">Site</span> and Surrounding Lava Flows, Galapagos Rift 86W: Techniques and Interpretations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Rosebud <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field was discovered in May 2002 in the Galapagos Rift near 86W during a series of Alvin dives and ABE autonomous vehicle surveys. Vertical-incidence digital imaging using a 3.1 Mpixel digital camera and strobe illumination from altitudes of 3-5m was carried out during the Alvin dives. A complete survey of the Rosebud <span class="hlt">vent</span> <span class="hlt">site</span> was carried out on Alvin Dive 3790. Submersible position was determined by post-cruise integration of 1.2 MHz bottom-lock Doppler sonar velocity data logged at 5Hz, integrated with heading and attitude data from a north-seeking fiber-optic gyroscope logged at 10Hz, and initialized with a surveyed-in long-baseline transponder navigation system providing geodetic position fixes at 15s intervals. The photo-mosaicing process consisted of three main stages: pre-processing, pair-wise image co-registration, and global alignment. Excellent image quality allowed us to avoid lens distortion correction, so images only underwent histogram equalization. Pair-wise co-registration of sequential frames was done partially automatically (where overlap exceeded 70 percent we employed a frequency-domain based technique), and partially manually (when overlap did not exceed 15 percent and manual feature extraction was the only way to find transformations relating the frames). Partial mosaics allowed us to determine which non-sequential frames had substantial overlap, and the corresponding transformations were found via feature extraction. Global alignment of the images consisted of construction of a sparse, nonlinear over-constrained system of equations reflecting positions of the frames in real-world coordinates. This system was solved using least squares, and the solution provided globally optimal positions of the frames in the overall mosaic. Over 700 images were mosaiced resulting in resolution of ~3 mm per pixel. The mosaiced area covers approximately 50 m x 60 m and clearly shows several biological zonations and distribution of lava flow morphologies, including what is interpreted as the contact between older lobate lava and the young sheet flow that hosts Rosebud <span class="hlt">vent</span> communities. Recruitment of tubeworms, mussels, and clams is actively occurring at more than five locations oriented on a NE-SW trend where <span class="hlt">vent</span> emissions occur through small cracks in the sheet flow. Large-scale views of seafloor <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span>, such as the one produced for Rosebud, are critical to properly understanding spatial relationships between <span class="hlt">hydrothermal</span> biological communities, <span class="hlt">sites</span> of focused and diffuse fluid flow, and the complex array of volcanic and tectonic features at mid-ocean ridge crests. These high-resolution perspectives are also critical to time-series studies where quantitative documentation of changes can be related to variations in <span class="hlt">hydrothermal</span>, magmatic and tectonic processes.</p> <div class="credits"> <p class="dwt_author">Rzhanov, Y.; Mayer, L.; Fornari, D.; Shank, T.; Humphris, S.; Scheirer, D.; Kinsey, J.; Whitcomb, L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">51</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2001AGUFMOS41A0444H"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> in an Unusual Geotectonic Setting: the Kairei and Edmond <span class="hlt">Vent</span> Fields, Central Indian Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Over the past 25 years, field investigations along the global mid-ocean ridge (MOR) system have indicated that <span class="hlt">hydrothermal</span> activity occurs in a range of geotectonic settings and is characterized by different styles of <span class="hlt">venting</span> and mineralization. In March-May 2001, we conducted multidisciplinary investigations of two <span class="hlt">hydrothermally</span> active areas on the Central Indian Ridge -- an intermediate-rate spreading system ( ~50-60 mm/yr). The Kairei <span class="hlt">vent</span> field (about 25° 20'S) is located in the first segment north of the Rodriguez Triple Junction (RTJ) and was discovered by Japanese scientists in August 2000. The Edmond <span class="hlt">vent</span> field (about 23° 53'S) is located two segments north of Kairei. Both <span class="hlt">vent</span> fields occur at the northern ends of segments with very straight rift valley walls, in the vicinity of rounder plan-view basins at non-transform discontinuities. The Kairei <span class="hlt">vent</span> field is located on a bench high on the stair-step eastern rift valley wall, nearly 7 km from the ridge axis, and at a depth range (2415-2460 m) ~1800 m shallower than the rift valley floor. Similarly, the Edmond <span class="hlt">vent</span> field is located high on the eastern rift valley wall about 6 km from the adjacent rift axis at a depth range of 3290-3320 m. It is constructed on a small protrusion that extends south from the eastern rift wall and that forms the northeast corner of a ~60 m deep basin. The Kairei and Edmond <span class="hlt">vent</span> fields are built on seafloor with a slope typically of 10-45° . High temperature <span class="hlt">venting</span> at both <span class="hlt">sites</span> is focused along a NW-SE trend (typically 100-120 m long and 80-90 m wide) and is likely fault-controlled. Both fields also include peripheral relict sulfide chimneys, old disaggregated sulfide structures, and massive sulfide talus, indicating that <span class="hlt">hydrothermal</span> activity has been focused at these <span class="hlt">sites</span> over long periods of time. Edmond is distinct from Kairei in its abundance of orange-brown, Fe-oxyhydroxide sediments that are several cm thick in depressions, and coat sulfide structures and talus. High-temperature <span class="hlt">venting</span> at both <span class="hlt">sites</span> is manifest as discrete clusters of large (up to 20 m tall, 2 m in diameter) chimneys with vigorous black smoker fluids emanating from multiple orifices, similar to the black smoker complex at the TAG <span class="hlt">hydrothermal</span> field. Within and between the clusters at Edmond, smaller (up to 5 m high), branched structures ornament the seafloor and discharge black smoker fluids at slower flow rates. "Beehive" structures, similar to those at the Snake Pit <span class="hlt">hydrothermal</span> field, are common at Edmond. Like many other MOR <span class="hlt">vent</span> fields, diffuse flow is widespread at Edmond - unlike Kairei, where it is largely restricted to the flanks of the black smoker complexes. The location of the Kairei and Edmond <span class="hlt">vent</span> fields high up on the walls of the rift valley is unusual. The only other known <span class="hlt">site</span> in a similar setting is the Sea Cliff <span class="hlt">hydrothermal</span> field on the Gorda Ridge. However, both Kairei and Edmond are noteworthy in being further away from the ridge axis (>6 km compared with ~2.5 km at Sea Cliff) and having higher temperature <span class="hlt">hydrothermal</span> fluids (382° C compared with 305° C at Sea Cliff). Such high temperatures require a relatively shallow heat source, which raises important questions about the nature of both the heat source and the fault-controlled permeability structure of the rift valley walls.</p> <div class="credits"> <p class="dwt_author">Humphris, S. E.; Fornari, D. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">52</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40202368"> <span id="translatedtitle">Trophic relationships among invertebrates at the Kairei <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field (Central Indian Ridge)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">.   Exploration of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> systems in locations remote from well-studied <span class="hlt">sites</span> allows ecologists to determine the degree\\u000a of <span class="hlt">site</span>-specific variation in trophic relationships among communities. A preliminary outline of the trophic structure of the\\u000a Kairei <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> community on the Central Indian Ridge (25°19.23?S; 70°02.42?E) is provided here, based on analysis\\u000a of collections from an April 2001 expedition. Invertebrate</p> <div class="credits"> <p class="dwt_author">C. L. Van Dover</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">53</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/543373"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> is Lake Tanganyika, East African Rift system</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Sublacustrine <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> with associated massive sulfides were discovered during April 1987 at Pemba and Cape Banza on the Zaire side of the northern basin of Lake Tanganyika, East African Rift system. New investigations by a team of ten scuba divers during the multinational (France, Zaire, Germany, and Burundi) TANGANYDRO expedition (August-October 1991) found <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> down to a depth of 46 m along north-trending active faults bounding the Tanganyika rift on the western side. Temperatures from 53 to 103 {degrees}C were measured in <span class="hlt">hydrothermal</span> fluids and sediments. Veins of massive sulfides 1-10 cm thick (pyrite and marcasite banding) were found associated with <span class="hlt">vents</span> at the Pemba <span class="hlt">site</span>. At Cape Banza, active <span class="hlt">vents</span> are characterized by 1-70-cm-high aragonite chimneys, and there are microcrystalline pyrite coatings on the walls of <span class="hlt">hydrothermal</span> pipes. <span class="hlt">Hydrothermal</span> fluid end members show distinctive compositions at the two <span class="hlt">sites</span>. The Pemba end member is a NaHCO{sub 3}-enriched fluid similar to the NaHCO{sub 3} thermal fluids form lakes Magadi and Bogoria in the eastern branch of the rift. The Cape Banza end member is a solution enriched in NaCl. Such brines may have a deep-seated basement origin, as do the Uvinza NaCl brines on the eastern flank of the Tanganyika basin. Geothermometric calculations have yielded temperatures of fluid-rock interaction of 219 and 179 {degrees}C in the Pemba and Cape Banza systems, respectively. Abundant white or reddish-brown microbial colonies resembling Beggiatoa mats were found surrounding the active <span class="hlt">vents</span>. Thermal fluid circulation is permitted by opening of cracks related to 130{degrees}N normal-dextral faults that intersect the north-south major rift trend. The sources of heat for such <span class="hlt">hydrothermal</span> systems may relate to the existence of magmatic bodies under the rift, which is suggested by the isotopic composition of carbon dioxide released at Pemba and Cape Banza. 21 refs., 2 figs.</p> <div class="credits"> <p class="dwt_author">Tiercelin, J.J. [Universite de Bretagne Occidentale, Brest (France)] [Universite de Bretagne Occidentale, Brest (France); Pflumio, C.; Castrec, M. [Universite Paris VI, Paris (France)] [and others] [Universite Paris VI, Paris (France); and others</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">54</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/42046319"> <span id="translatedtitle">Liquid CO2 <span class="hlt">venting</span> on the seafloor: Yonaguni Knoll IV <span class="hlt">hydrothermal</span> system, Okinawa Trough</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We determined the chemical and isotopic compositions of the liquid CO2 found on Yonaguni IV knoll <span class="hlt">hydrothermal</span> <span class="hlt">site</span>, as well as those in <span class="hlt">hydrothermal</span> fluid <span class="hlt">venting</span> from the surrounding chimneys. The delta13C of both CO2 and CH4 in the liquid CO2 almost coincide with those in the <span class="hlt">hydrothermal</span> fluid, suggesting that the liquid CO2 must be derived from the <span class="hlt">hydrothermal</span></p> <div class="credits"> <p class="dwt_author">Uta Konno; Urumu Tsunogai; Fumiko Nakagawa; Miwako Nakaseama; Jun-ichiro Ishibashi; Takuro Nunoura; Ko-ichi Nakamura</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">55</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/44255082"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> in Lake Tanganyika, East African, Rift system</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Sublacustrine <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> with associated massive sulfides were discovered during April 1987 at Pemba and Cape Banza on the Zaire side of the northern basin of Lake Tanganyika, East African Rift system. New investigations by a team of ten scuba divers during the multinational (France, Zaire, Germany, and Burundi) TANGANYDRO expedition (August-October 1991) found <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> down to a depth</p> <div class="credits"> <p class="dwt_author">Jean-Jacques Tiercelin; Catherine Pflumio; Maryse Castrec; Jacques Boulégue; Pascal Gente; Joël Rolet; Christophe Coussement; Karl O. Stetter; Robert Huber; Sony Buku; Wafula Mifundu</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">56</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/55358138"> <span id="translatedtitle">Hydrogen is an energy source for <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> symbioses</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The discovery of deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in 1977 revolutionized our understanding of the energy sources that fuel primary productivity on Earth. <span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> ecosystems are dominated by animals that live in symbiosis with chemosynthetic bacteria. So far, only two energy sources have been shown to power chemosynthetic symbioses: reduced sulphur compounds and methane. Using metagenome sequencing, single-gene fluorescence in situ</p> <div class="credits"> <p class="dwt_author">Jillian M. Petersen; Frank U. Zielinski; Thomas Pape; Richard Seifert; Cristina Moraru; Rudolf Amann; Stephane Hourdez; Peter R. Girguis; Scott D. Wankel; Valerie Barbe; Eric Pelletier; Dennis Fink; Christian Borowski; Wolfgang Bach; Nicole Dubilier</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">57</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/r87487773343vh77.pdf"> <span id="translatedtitle">Dispersal at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>: a summary of recent progress</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The discovery of <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> along the Galapagos Rift in 1977 opened up one of the most dynamic and productive research themes in marine biology. In the intervening 25 years, <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> faunas have been described from the eastern, northeastern and western Pacific, the mid-Atlantic Ridge and the Indian Ocean in the region of the Rodriguez Triple Junction. In addition,</p> <div class="credits"> <p class="dwt_author">Paul A. Tyler; Craig M. Young</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">58</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/11557843"> <span id="translatedtitle">Biogeography and ecological setting of Indian Ocean <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Within the endemic invertebrate faunas of <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, five biogeographic provinces are recognized. Invertebrates at two Indian Ocean <span class="hlt">vent</span> fields (Kairei and Edmond) belong to a sixth province, despite ecological settings and invertebrate-bacterial symbioses similar to those of both western Pacific and Atlantic <span class="hlt">vents</span>. Most organisms found at these Indian Ocean <span class="hlt">vent</span> fields have evolutionary affinities with western Pacific <span class="hlt">vent</span> faunas, but a shrimp that ecologically dominates Indian Ocean <span class="hlt">vents</span> closely resembles its Mid-Atlantic counterpart. These findings contribute to a global assessment of the biogeography of chemosynthetic faunas and indicate that the Indian Ocean <span class="hlt">vent</span> community follows asymmetric assembly rules biased toward Pacific evolutionary alliances. PMID:11557843</p> <div class="credits"> <p class="dwt_author">Van Dover, C L; Humphris, S E; Fornari, D; Cavanaugh, C M; Collier, R; Goffredi, S K; Hashimoto, J; Lilley, M D; Reysenbach, A L; Shank, T M; Von Damm, K L; Banta, A; Gallant, R M; Gotz, D; Green, D; Hall, J; Harmer, T L; Hurtado, L A; Johnson, P; McKiness, Z P; Meredith, C; Olson, E; Pan, I L; Turnipseed, M; Won, Y; Young, C R; Vrijenhoek, R C</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-10-26</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">59</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.sb-roscoff.fr/Ecchis/pdf/07-Company-MarEcol.pdf"> <span id="translatedtitle">Adaptation of the antioxidant defence system in <span class="hlt">hydrothermal-vent</span> mussels (Bathymodiolus azoricus) transplanted between two Mid-Atlantic Ridge <span class="hlt">sites</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The <span class="hlt">vent</span> mussel Bathymodiolus azoricus is the dominant member of the Nor- thern Mid-Atlantic Ridge (MAR) <span class="hlt">hydrothermal</span> megafauna, and lives in an environment characterized by temporal and spatial variations in the levels of heavy metals, methane and hydrogen sulphide, substances which are known to increase reactive oxygen species levels in the tissues of exposed organisms. To evaluate the effects of</p> <div class="credits"> <p class="dwt_author">Angela Serafim; Richard Cosson; Aline Fiala-Médioni; David R. Dixon; Maria João Bebianno</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">60</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002JVGR..115..257D"> <span id="translatedtitle">Discovery of active <span class="hlt">hydrothermal</span> <span class="hlt">venting</span> in Lake Taupo, New Zealand</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Horomatangi geothermal system of Lake Taupo, New Zealand, is a sub-lacustrine equivalent of subaerial geothermal activity nearby in the Taupo Volcanic Zone (TVZ). The setting of this system is rare within the TVZ as it is directly associated with an individual volcanic feature, that of the 1.8 ka Taupo eruption <span class="hlt">vent</span>. Two distinct <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> areas, named Te Hoata and Te Pupu, have been discovered during dives with the submersible Jago. <span class="hlt">Venting</span> of gases was seen at both <span class="hlt">sites</span> and hot water (up to 45°C) discharges at the Te Pupu <span class="hlt">site</span>. Dilute water samples have concentrations of SO 4, Cl, Na and SiO 2 above ambient lake water values. Gas samples have compositions similar to other TVZ geothermal systems. Gas geothermometers indicate the existence of a high-temperature <span class="hlt">hydrothermal</span> environment beneath the lake with reservoir temperatures in excess of 300°C. Chimney structures were found at the Te Pupu <span class="hlt">site</span>. They are up to 30 cm tall and mineralized by an 'epithermal' suite of elements, including S, Hg, As, Sb and Tl. The walls of the chimneys are largely composed of diatoms and strands of silicified filamentous bacteria embedded in an amorphous silica groundmass. Bacterial mats are commonly associated with the gas <span class="hlt">vents</span> and also occur at two hot springs. Close to the <span class="hlt">vents</span>, commonly perched on top of dead chimneys and/or exposed outcrops, are dense assemblages of what are probably a new species of sponge of the genus Heterorotula. The sponges host a notably diversified, associated invertebrate fauna and represent a previously unseen biomass on the lake floor. The sponges appear to have bored into the mineralized chimneys.</p> <div class="credits"> <p class="dwt_author">de Ronde, C. E. J.; Stoffers, P.; Garbe-Schönberg, D.; Christenson, B. W.; Jones, B.; Manconi, R.; Browne, P. R. L.; Hissmann, K.; Botz, R.; Davy, B. W.; Schmitt, M.; Battershill, C. N.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-06-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_2");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a style="font-weight: bold;">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a 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src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_3");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a style="font-weight: bold;">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_5");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">61</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012GGG....13.7007S"> <span id="translatedtitle">Fluid and gas fluxes from the Logatchev <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> area</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Logatchev <span class="hlt">hydrothermal</span> field at 14°45'N on the MAR is characterized by gas plumes that are enriched in methane and helium compared to the oceanic background. We investigated CH4 concentration and ?13C together with ?3He in the water column of that region. These data and turbidity measurements indicate that apart from the known <span class="hlt">vent</span> fields, another <span class="hlt">vent</span> <span class="hlt">site</span> exists northeast of the <span class="hlt">vent</span> field Logatchev 1. The distribution of methane and 3He concentrations along two sections were used in combination with current measurements from lowered acoustic Doppler current profilers (LADCP) to calculate the horizontal plume fluxes of these gases. According to these examinations 0.02 ?mol s-1 of 3He and 0.21 mol s-1 of methane are transported in a plume that flows into a southward direction in the central part of the valley. Based on 3He measurements of <span class="hlt">vent</span> fluid (22 ± 6 pM), we estimate a total <span class="hlt">vent</span> flux in this region of about 900 L s-1 and a total flux of CH4 of 3.2 mol s-1.</p> <div class="credits"> <p class="dwt_author">Schmale, Oliver; Walter, Maren; Schneider von Deimling, Jens; Sültenfuß, Jürgen; Walker, Sharon; Rehder, Gregor; Keir, Robin</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">62</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/53367987"> <span id="translatedtitle">Raman Spectroscopy at Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In this presentation we will describe the development and optimization of a custom submersible Raman instrument that was successfully deployed in one of the harshest environments on the planet, <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> systems. The primary objective of this project was to develop a multi-platform, broad spectral chemical sensor for investigating <span class="hlt">hydrothermal</span> processes in the deep ocean. Mid-ocean ridge <span class="hlt">hydrothermal</span> systems are</p> <div class="credits"> <p class="dwt_author">W. J. Thompson; B. J. Marquardt; M. D. Lilley</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">63</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20080047210&hterms=dive+computers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddive%2Bcomputers"> <span id="translatedtitle">Deep-Sea <span class="hlt">Hydrothermal-Vent</span> Sampler</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">An apparatus is being developed for sampling water for signs of microbial life in an ocean <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> at a depth of as much as 6.5 km. Heretofore, evidence of microbial life in deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> has been elusive and difficult to validate. Because of the extreme conditions in these environments (high pressures and temperatures often in excess of 300 C), deep-sea <span class="hlt">hydrothermal</span>- <span class="hlt">vent</span> samplers must be robust. Because of the presumed low density of biomass of these environments, samplers must be capable of collecting water samples of significant volume. It is also essential to prevent contamination of samples by microbes entrained from surrounding waters. Prior to the development of the present apparatus, no sampling device was capable of satisfying these requirements. The apparatus (see figure) includes an intake equipped with a temperature probe, plus several other temperature probes located away from the intake. The readings from the temperature probes are utilized in conjunction with readings from flowmeters to determine the position of the intake relative to the <span class="hlt">hydrothermal</span> plume and, thereby, to position the intake to sample directly from the plume. Because it is necessary to collect large samples of water in order to obtain sufficient microbial biomass but it is not practical to retain all the water from the samples, four filter arrays are used to concentrate the microbial biomass (which is assumed to consist of particles larger than 0.2 m) into smaller volumes. The apparatus can collect multiple samples per dive and is designed to process a total volume of 10 L of <span class="hlt">vent</span> fluid, of which most passes through the filters, leaving a total possibly-microbe-containing sample volume of 200 mL remaining in filters. A rigid titanium nose at the intake is used for cooling the sample water before it enters a flexible inlet hose connected to a pump. As the water passes through the titanium nose, it must be cooled to a temperature that is above a mineral-precipitation temperature of 100 C but below the upper working temperature (230 C) of switching valves and tubes in the apparatus. The sample water then passes into a manifold tube, from whence the switching valves can direct the water through either a bypass tube or any one of the filter arrays, without contamination from a previous sample. Each filter array consists of series of filters having pore sizes decreasing in the direction of flow: 90-, 60-, 15-, and 7-micron prefilters and a large-surface-area 0.2-micron collection filter. All the filter taps are located between the intake and the bypass tube so that each time the bypass tube is used, the entire manifold tube is flushed as well.</p> <div class="credits"> <p class="dwt_author">Behar, Alberto E.; Venkateswaran, Kasthur; Matthews, Jaret B.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">64</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009DSRII..56.1577E"> <span id="translatedtitle">Evidence for a chemoautotrophically based food web at inactive <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> (Manus Basin)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> are ephemeral systems. When <span class="hlt">venting</span> shuts down, sulfide-dependent taxa die off, and non-<span class="hlt">vent</span> taxa can colonize the hard substrata. In Manus Basin (Papua New Guinea), where <span class="hlt">hydrothermally</span> active and inactive <span class="hlt">sites</span> are interspersed, hydroids, cladorhizid sponges, barnacles, bamboo corals, and other invertebrate types may occupy inactive <span class="hlt">sites</span>. Carbon and nitrogen isotopic compositions of animals occupying inactive <span class="hlt">sites</span> are consistent with nutritional dependence on either chemoautotrophically or photosynthetically produced organic material, but sulfur isotopic compositions of these animals point to a chemoautotrophic source of sulfur from dissolved sulfide in <span class="hlt">vent</span> fluids rather than sulfur derived from seawater sulfate through photosynthesis. Given that suspension-feeding and micro-carnivorous invertebrates are the biomass dominants at inactive <span class="hlt">sites</span>, the primary source of chemoautotrophic nutrition is likely suspended particulates and organisms delivered from nearby active <span class="hlt">vents</span>.</p> <div class="credits"> <p class="dwt_author">Erickson, K. L.; Macko, S. A.; Van Dover, C. L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-09-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">65</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1994EOSTr..75...44V"> <span id="translatedtitle">Light at deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We usually think of the bottom of the sea as a dark environment, lit only by flashes of bioluminescent light. Discovery of light associated with geothermal processes at deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> forces us to qualify our textbook descriptions of the seafloor as a uniformly dark environment. While a very dim glow emitted from high temperature (350°) <span class="hlt">vents</span> (black smokers) at mid-oceanic ridge spreading centers has been documented [Van Dover et al, 1988], the source of this light and its role, if any, in the evolution and adaptation of photobiochemical processes have yet to be determined. Preliminary studies indicate that thermal radiation alone may account for the “glow” ]Smith and Delaney, 1989] and that a novel photoreceptor in shrimp-colonizing black smoker chimneys may detect this “glow” [Van Dover et al., 1989; Pelli and Chamberlain, 1989]. A more controversial question, posed by C. L. Van Dover, J. R. Cann, and J. R. Delaney at the 1993 LITE Workshop at the Woods Hole Oceanographic Institution in Massachusetts, is whether there may be sufficient light of appropriate wavelengths to support geothermally driven photosynthesis by microorganisms.</p> <div class="credits"> <p class="dwt_author">Van Dover, Cindy Lee; Cann, J. R.; Cavanaugh, Colleen; Chamberlain, Steven; Delaney, John R.; Janecky, David; Imhoff, Johannes; Tyson, J. Anthony</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">66</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010AGUFM.V23A2385I"> <span id="translatedtitle">Geomicrobiology of <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> in Yellowstone Lake: Phylogenetic and Functional Analysis suggest Importance of Geochemistry (Invited)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Yellowstone Lake (Yellowstone National Park, WY, USA) is a large, high-altitude, fresh-water lake that straddles the most recent Yellowstone caldera, and is situated on top of significant <span class="hlt">hydrothermal</span> activity. An interdisciplinary study is underway to evaluate the geochemical and geomicrobiological characteristics of several <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> environments sampled using a remotely operated vehicle, and to determine the degree to which these <span class="hlt">vents</span> may influence the biology of this young freshwater ecosystem. Approximately six different <span class="hlt">vent</span> systems (locations) were sampled during 2007 and 2008, and included water obtained directly from the <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> as well as biomass and sediment associated with these high-temperature environments. Thorough geochemical analysis of these <span class="hlt">hydrothermal</span> environments reveals variation in pH, sulfide, hydrogen and other potential electron donors that may drive primary productivity. The concentrations of dissolved hydrogen and sulfide were extremely high in numerous <span class="hlt">vents</span> sampled, especially the deeper (30-50 m) <span class="hlt">vents</span> located in the Inflated Plain, West Thumb, and Mary Bay. Significant dilution of <span class="hlt">hydrothermal</span> fluids occurs due to mixing with surrounding lake water. Despite this, the temperatures observed in many of these <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> range from 50-90 C, and elevated concentrations of constituents typically associated with geothermal activity in Yellowstone are observed in waters sampled directly from <span class="hlt">vent</span> discharge. Microorganisms associated with elemental sulfur mats and filamentous ‘streamer’ communities of Inflated Plain and West Thumb (pH range 5-6) were dominated by members of the deeply-rooted bacterial Order Aquificales, but also contain thermophilic members of the domain Archaea. Assembly of metagenome sequence from the Inflated Plain <span class="hlt">vent</span> biomass and to a lesser extent, West Thumb <span class="hlt">vent</span> biomass reveal the importance of Sulfurihydrogenibium-like organisms, also important in numerous terrestrial geothermal outflow channels of YNP. Analysis of functional genes present in the consensus metagenome sequence representing these populations indicate metabolic potential for oxidation of reduced sulfur and hydrogen, both of which are present at high concentrations in these <span class="hlt">vent</span> ecosystems. Metagenome sequence of biomass associated with sediments from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> at Mary Bay (50 m depth) suggest greater archaeal and bacterial diversity in this environment, which may be due to higher concentrations of hydrogen, iron, and manganese measured in these environments. Results from metagenome sequence and modest 16S rRNA gene surveys from <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> biomass indicate that several groups of novel thermophilic archaea inhabit these <span class="hlt">sites</span>, and in many cases, are represented by organisms not found in YNP terrestrial geothermal environments that have been characterized to date. The <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> from Inflated Plain and West Thumb indicate a linkage between various geochemical attributes (sulfide, hydrogen) and the metabolic potential associated with dominant Aquificales populations present in these communities.</p> <div class="credits"> <p class="dwt_author">Inskeep, W. P.; Macur, R.; Jay, Z.; Clingenpeel, S.; Tenney, A.; Lavalvo, D.; Shanks, W. C.; McDermott, T.; Kan, J.; Gorby, Y.; Morgan, L. A.; Yooseph, S.; Varley, J.; Nealson, K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">67</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/53990330"> <span id="translatedtitle">Energy Filtering Transmission Electron Tomography (EFTET) of Bacteria-Mineral Associations within the Deep sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Shrimp Rimicaris exoculata</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The chemical and temperature conditions around deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> are both dynamic and extreme, yet the shrimp Rimicaris exoculata flourishes around these environments on the Mid--Atlantic Ridge (MAR). Epibiotic bacteria and minerals found within the branchial chamber (BC) of the shrimp are of great interest in the search for a chemical model for the Rainbow MAR <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span>.</p> <div class="credits"> <p class="dwt_author">L. M. Anderson; S. Halary; J. Lechaire; G. Frébourg; T. Boudier; M. Zbinden; J. Laval; S. Marco; F. Gaill</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">68</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFMOS22A..05N"> <span id="translatedtitle">Potential biomass in deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystem</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Since the first discovery of black smoker <span class="hlt">vents</span> hosting chemosynthetic macrofaunal communities (Spiess et al., 1980), submarine <span class="hlt">hydrothermal</span> systems and associated biota have attracted interest of many researchers (e.g., Humphris et al., 1995; Van Dover, 2000; Wilcock et al., 2004). In the past couple of decades, particular attention has been paid to chemolithoautotrophic microorganisms that sustain the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span>-endemic animal communities as the primary producer. This type of microorganisms obtains energy from inorganic substances (e.g., sulfur, hydrogen, and methane) derived from <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fluids, and is often considered as an important modern analogue to the early ecosystems of the Earth as well as the extraterrestrial life in other planets and moons (e.g., Jannasch and Mottl, 1985; Nealson et al., 2005; Takai et al., 2006). Even today, however, the size of this type of chemosynthetic deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystem is largely unknown. Here, we present geophysical and geochemical constraints on potential biomass in the deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystem. The estimation of the potential biomass in the deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystem is based on <span class="hlt">hydrothermal</span> fluid flux calculated from heat flux (Elderfield and Schltz, 1996), maximum chemical energy available from metabolic reactions during mixing between <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fluids and seawater (McCollom, 2007), and maintenance energy requirements of the chemolithoautotrophic microorganisms (Hoehler, 2004). The result shows that the most of metabolic energy sustaining the deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystem is produced by oxidation reaction of reduced sulfur, although some parts of the energy are derived from hydrogenotrophic and methanotrophic reactions. The overall total of the potential biomass in deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystem is calculated to be much smaller than that in terrestrial ecosystems including terrestrial plants. The big difference in biomass between the chemosynthetic deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystem and the photosynthetic terrestrial ecosystems could reflect the difference between energy fluxes from the Sun and the Earth's interior. Based on the result, it can be concluded that the deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystem is quite minor (although interesting and important) component of the modern Earth's biosphere.</p> <div class="credits"> <p class="dwt_author">Nakamura, K.; Takai, K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">69</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://alrlab.pdx.edu/media/longnecker2001.pdf"> <span id="translatedtitle">Expansion of the geographic distribution of a novel lineage of O-Proteobacteria to a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span> on the Southern East Paci¢c Rise</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The diversity associated with a microbial mat sample collected from a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> on the Southern East Pacific Rise was determined using a molecular phylogenetic approach based on the comparison of sequences from the small subunit ribosomal RNA gene (16S rDNA). The DNA was extracted from the sample and the 16S rDNA was amplified by PCR. Sixteen different phylotypes</p> <div class="credits"> <p class="dwt_author">Krista Longnecker; Anna-Louise Reysenbach</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">70</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUFMOS43C..05X"> <span id="translatedtitle">Heat flux measured acoustically at Grotto <span class="hlt">Vent</span>, a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> cluster on the Endeavour Segment, Juan de Fuca Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Over the past several decades, quantifying the heat output has been a unanimous focus of studies at <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields discovered around the global ocean. Despite their importance, direct measurements of <span class="hlt">hydrothermal</span> heat flux are very limited due to the remoteness of most <span class="hlt">vent</span> <span class="hlt">sites</span> and the complexity of <span class="hlt">hydrothermal</span> <span class="hlt">venting</span>. Moreover, almost all the heat flux measurements made to date are snapshots and provide little information on the temporal variation that is expected from the dynamic nature of a <span class="hlt">hydrothermal</span> system. The Cabled Observatory <span class="hlt">Vent</span> Imaging Sonar (COVIS, https://<span class="hlt">sites</span>.google.com/a/uw.edu/covis/) is currently connected to the Endeavour node of the NEPTUNE Canada observatory network (http://www.neptunecanada.ca) to monitor the <span class="hlt">hydrothermal</span> plumes issuing from a <span class="hlt">vent</span> cluster (Grotto) on the Endeavour Segment of the Juan de Fuca Ridge. COVIS is acquiring a long-term (20-months to date) time series of the vertical flow rate and volume flux of the <span class="hlt">hydrothermal</span> plume above Grotto through the Doppler analysis of the acoustic backscatter data (Xu et al., 2013). We then estimate the plume heat flux from vertical flow rate and volume flux using our newly developed inverse method. In this presentation, we will briefly summarize the derivation of the inverse method and present the heat-flux time series obtained consequently with uncertainty quantification. In addition, we compare our heat-flux estimates with the one estimated from the plume in-situ temperatures measured using a Remotely Operative Vehicle (ROV) in 2012. Such comparison sheds light on the uncertainty of our heat flux estimation. Xu, G., Jackson, D., Bemis, K., and Rona, P., 2013, Observations of the volume flux of a seafloor <span class="hlt">hydrothermal</span> plume using an acoustic imaging sonar, Geochemistry, Geophysics Geosystems, 2013 (in press).</p> <div class="credits"> <p class="dwt_author">Xu, G.; Jackson, D. R.; Bemis, K. G.; Rona, P. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">71</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40779797"> <span id="translatedtitle">A multi-isotope study of deep-sea mussels at three different <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> in the northwestern Pacific</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">To investigate symbiotic bacterial ecosystems at different deep-sea <span class="hlt">hydrothermal</span> systems in the northwestern Pacific, compound-specific carbon and hydrogen isotope analyses of lipid biomarkers have been performed in addition to bulk C, H, N, S and O isotope analyses on Bathymodiolus mussels from the Hatoma seamount (B. platifrons), the Daiyon-Yonaguni (Yonaguni) knoll (B. platifrons), and the Suiyo seamount (B. septemdierum). The</p> <div class="credits"> <p class="dwt_author">Hiroshi Naraoka; Taku Naito; Toshiro Yamanaka; Urumu Tsunogai; Katsunori Fujikura</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">72</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/52665520"> <span id="translatedtitle">Bacterial Diets of Primary Consumers at <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Chemical energy produced by mixing <span class="hlt">hydrothermal</span> fluids and seawater supports dense biological communities on mid-ocean ridges. The base of the food web at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> is formed by chemolithoautotrophic bacteria that use the energy from the oxidation of reduced chemicals to fix inorganic carbon into simple sugars. With the exception of a few species that have chemolithoautotropic bacterial symbionts,</p> <div class="credits"> <p class="dwt_author">B. Govenar; T. M. Shank</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">73</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1998DSRI...45.2105H"> <span id="translatedtitle">Extensive deep-sea dispersal of postlarval shrimp from a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> fields on the Mid-Atlantic Ridge (MAR) are small (no more than 0.1-1.0 km 2) and widely spaced (a reported average of one field per 175 km between 11°N and 40°N). Their faunas are similar and usually dominated by shrimp of the family Bresiliidae. Little is known about the way these animals (and other members of the <span class="hlt">vent</span> fauna) disperse and colonize new <span class="hlt">vents</span>. <span class="hlt">Vent</span> shrimp juveniles have been taken close to certain <span class="hlt">vent</span> <span class="hlt">sites</span>, and in midwater, but their larvae and postlarvae have not been captured. We report here that bresiliid shrimp postlarvae are very widely dispersed around the Broken Spur <span class="hlt">vent</span> field and extend into the next MAR segment and the Atlantis Fracture Zone beyond. The populations show density gradients declining both vertically and horizontally from the <span class="hlt">vent</span> <span class="hlt">site</span>, in contrast to the overall pelagic biomass. This is the furthest recorded dispersal (>100 km) of identified larvae from a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> and is sufficient to give them access to adjacent <span class="hlt">vent</span> fields and thus the scope for colonising new <span class="hlt">sites</span>.</p> <div class="credits"> <p class="dwt_author">Herring, P. J.; Dixon, D. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">74</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2001AGUFMOS21B0440T"> <span id="translatedtitle">High-resolution geophysical mapping of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> systems at Endeavour Ridge, Juan de Fuca</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A detailed and systematic geophysical mapping program was carried out over the Endeavour <span class="hlt">hydrothermal</span> observatory area in 2000 and 2001 using the remotely operated vehicle (ROV) Jason. The ROV collected high-resolution swath bathymetry using a Simrad SM2000 sonar system and three-component magnetic field data using a vector magnetometer. The survey mapped an area ~3.5 km along the spreading axis and 1 km across-axis with a trackline spacing of ~40 m at an altitude of ~20 m. The survey covers both the Main Endeavour <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> Field (MEF) and the High Rise (HR) <span class="hlt">vent</span> field ~2 km to the north. The SM2000 bathymetry is detailed enough to resolve all of the major <span class="hlt">hydrothermal</span> edifices present within these two main <span class="hlt">vent</span> fields, presenting for the first time, a quantitative assessment of the location and size of these <span class="hlt">vent</span> edifices. In addition, the bathymetry provides information on the presence of other <span class="hlt">venting</span> areas and relict <span class="hlt">vent</span> areas. These new bathymetry data provide a benchmark basemap for future studies of the <span class="hlt">vent</span> systems at MEF and HR. While bathymetry data provide the location and surficial extent of <span class="hlt">venting</span> structures, the magnetic field data provides an estimate of the subsurface structure. The magnetic field data show that each of the known <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> areas are associated with strong and well-defined circular magnetic anomaly lows. Other zones of <span class="hlt">hydrothermal</span> activity, previously not known to exist and relict areas of past <span class="hlt">hydrothermal</span> activity, are also found to be associated with magnetic anomaly lows. The MEF <span class="hlt">vent</span> field has two main <span class="hlt">venting</span> fields: the northern <span class="hlt">vent</span> group composed of Grotto, Dante, Crypto and Hulk and the southern <span class="hlt">vent</span> group comprised of Bastille, S&M, and Milli-Q. These two <span class="hlt">vent</span> groups have clearly separate and discretely defined circular (~100 m in diameter) magnetic low zones associated with them. These anomalies imply a pipe-like source region beneath each of the <span class="hlt">vent</span> areas. This pipe geometry is compatible with ophiolite observations and suggests a narrow zone of highly altered crust produced by channelized subsurface upflow zone of hot fluid. The location of the two anomalies adjacent, but separate from one another suggests that these upflow zones are clearly independent between the two <span class="hlt">venting</span> areas at least to a depth in the crust that forms the magnetic layer. Anomaly lows were also found associated with <span class="hlt">venting</span> along the western rift valley wall just to the northwest of MEF. A new <span class="hlt">vent</span> <span class="hlt">site</span> was discovered ~500 m north of the northern edge of MEF associated with a large circular anomaly low, ~150 m in diameter. To the north, the HR <span class="hlt">vent</span> field is also associated with two magnetic low regions, each ~75 m in diameter. In this case, the magnetic lows are offset slightly to the west, implying a dipping zone perhaps associated with normal faults that bound the central horst block. Another magnetic low to the southeast of the HR horst block is associated with a well-developed stockwork zone. The almost one-to-one correspondence between magnetization lows and <span class="hlt">hydrothermal</span> <span class="hlt">venting</span> suggests that the magnetic properties of ocean crust are intimately related to the presence of <span class="hlt">hydrothermal</span> activity. The volcanic crust is either being severely attenuated by <span class="hlt">hydrothermal</span> alteration or it is above the Curie temperature and not magnetized. The association of anomaly lows with zones of relict <span class="hlt">hydrothermal</span> activity suggests that alteration rather than thermal demagnetization is the primary source of these anomalies.</p> <div class="credits"> <p class="dwt_author">Tivey, M. A.; Johnson, H. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">75</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008AGUFM.B53D..08O"> <span id="translatedtitle">Isolation and Stability of Distinct Subsurface Microbial Communities Associated with Two <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Systems</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Subseafloor microbial communities may be important in global primary production and biogeochemical cycling. However, too little is known about the physiological and phylogenetic diversity and activity of these communities to assess this potential, and understanding the temporal and spatial variability in microbial community structure is critical. The microbial community structure of five geographically distinct <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> located within the Axial Seamount caldera, and four geographically distinct <span class="hlt">vents</span> within the Main Endeavour Field, Juan de Fuca Ridge, were examined over six years. Terminal restriction fragment length polymorphism (tRFLP) and 16S rRNA gene sequence analyses were used to determine the bacterial and archaeal diversity, and the statistical software Primer was used to compare <span class="hlt">vent</span> microbiology, temperature and fluid chemistry. Statistical analysis of <span class="hlt">vent</span> fluid temperature and chemical composition shows that there are significant differences between <span class="hlt">vents</span> in any year, and persistent differences in composition between one of the Axial <span class="hlt">vents</span> compared to the rest of the <span class="hlt">vents</span>. For the majority of <span class="hlt">vents</span>, however, the fluid composition changed over time such that separate <span class="hlt">vents</span> do not maintain a statistically distinct composition. In contrast, the subseafloor microbial communities associated with individual <span class="hlt">vents</span> also changed from year to year but each location maintained a distinct community structure (based on tRFLP and 16S rRNA gene sequence analyses) that was significantly different and greater than 60-percent dissimilar from all other <span class="hlt">vents</span> included in this study. At Axial, epsilon-proteobacterial microdiversity is shown to be important in distinguishing <span class="hlt">vent</span> communities. The deeper, high-temperature archaeal communities have more overlap between <span class="hlt">sites</span>. We propose that persistent <span class="hlt">venting</span> at many diffuse <span class="hlt">sites</span> over time creates the potential to isolate and stabilize diverse microbial community structures between <span class="hlt">vents</span>. Variation in dilution patterns along discrete flow channels feeding diffuse seafloor <span class="hlt">vents</span> promotes microbial diversity and uniqueness of different diffuse <span class="hlt">vent</span> <span class="hlt">sites</span>, especially among the thermophilic Bacteria within the 5-50°C sub-seafloor temperature range.</p> <div class="credits"> <p class="dwt_author">Opatkiewicz, A. D.; Butterfield, D. A.; Baross, J. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">76</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002AGUFM.V72A1282O"> <span id="translatedtitle">Euryhaline Halophilic Microorganisms From the Suiyo Seamount <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The euryhaline halophilic microorganisms grow in a wide salinity range from <3% NaCl (seawater equivalent) to >15% NaCl or to even saturation (about 30% NaCl). A number of euryhaline halophiles have been found in a wide range of habitats from oceanic and terrestrial regimes, from deep-sea <span class="hlt">vents</span> and seeps, and from Antarctic sea ice and terrains. We have isolated the euryhaline strains independently from a Mid-Atlantic Ridge <span class="hlt">vent</span> fluids and Antarctic terrains are closely related species of the genus Halomonas. Some euryhaline halophiles maintain intracellular osmotic balance by controlling the concentration of compatible solute such as ectoine. This compatible solute not only stabilizes the proteins from denaturation caused by high salt concentration but also serves as a protectant against stresses such as heating, freezing and drying. The sub-seafloor structure of a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> is highly complicated with mosaic heterogeneity of physicochemical parameters such as temperature and salinity. This premise led us to the hypothesis that some euryhaline halophiles including Halomonas species well adapt to a wide salinity-ranged habitat in the sub-<span class="hlt">vent</span>. To test this hypothesis, isolation and characterization of euryhaline halophiles from the Suiyo Seamount <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> were conducted the drill-cored rock samples from the <span class="hlt">sites</span> APSK-02, 03, and 07 and the filter-trapped fluid particle samples from the <span class="hlt">sites</span> APSK-01 and 05 were used. For initial cultivation, a heterotrophic bacterial medium of 15% NaCl was used. The samples was added to the medium and incubated under both aerobic and anaerobic conditions at room temperature. A total of 5 euryhaline halophilic strains were obtained and phylogenetically characterized: two strains (both related to Marinobacter) from APSK-02 core section 2; one strain (related to H. meridiana) from APSK-07 core section 3; and two strains (related to H. meridiana and H. variabilis) from APSK-01 trapped particles. In addition, some thermophilic halophiles that grow at 20% NaCl and 90 degree C were isolated from APSK-02, although phylogenetic and physioloigcal studies are under way. This research was supported by Archean Park project.</p> <div class="credits"> <p class="dwt_author">Okamoto, T.; Kimura, H.; Maruyama, A.; Naganuma, T.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">77</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2001AGUFM.T52A0923M"> <span id="translatedtitle">First Survey For Submarine <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> In NE Sulawesi, Indonesia</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The IASSHA-2001 cruise (Indonesia-Australia Survey for Submarine <span class="hlt">Hydrothermal</span> Activity) was successfully conducted from June 1 to June 29 on board Baruna Jaya VIII. Preliminary results are reported of the first expedition to locate and study submarine <span class="hlt">hydrothermal</span> activity in north east Sulawesi. Leg A focussed on Tomini Bay, a virtually unexplored Neogene sedimentary basin. Its objective was to test whether modern sediment-hosted <span class="hlt">hydrothermal</span> activity occurred on the sea floor. The results of new bathymetric mapping, sediment coring and CTD/transmissometer hydrocasts negate the likely presence in central Tomini Bay of large-scale modern analogues of <span class="hlt">hydrothermal</span> massive sulfide environments involving <span class="hlt">hydrothermal</span> <span class="hlt">venting</span> of basinal or magma-derived fluids into reduced sediments. It is possible that the "heat engine" required to drive circulation of basinal and <span class="hlt">hydrothermal</span> fluids is today too weak. Surveys around Colo volcano indicate that it may be in its final stage of evolution. Leg B studied the arc and behind-arc sectors of the Sangihe volcanic island chain extending northwards from Quaternary volcanoes on the northeastern tip of Sulawesi's North Arm, near Manado. West of the main active chain and extending northwards from Manado there is a subparallel ridge surmounted by a number of high (>2000 m) seamounts of uncertain age. Fifteen relatively high-standing submarine edifices were crossed during this leg, of which nine were tested for <span class="hlt">hydrothermal</span> activity by hydrocast and dredging. Eight <span class="hlt">sites</span> were known from previous bathymetric surveys, and seven are new discoveries made by narrow-beam or multibeam echo sounding. Two submarine edifices at least 1000 m high were discovered in the strait immediately north of Awu volcano on Sangihe Island. One, with crest at 206 m, is surrounded by a circular platform 300m deep which we infer to be a foundered fringing reef to a formerly emergent island. The other, lacking such a platform, appears relatively young and may be parasitic to Awu volcano. It has a summit crater or small caldera, about 800 m across and breached to the northwest. A dredge hauled within the caldera returned numerous un-abraded fragments of fresh pumiceous dacite glass with prominent phenocrysts of plagioclase, orthopyroxene and clinopyroxene, plus small angular fragments of a similar but less vesicular lithology. Coatings of soft ferruginous deposit on some fragments suggest that the caldera is <span class="hlt">hydrothermally</span> active. A highlight of the expedition was a visit to Banua Wuhu, classed as an active volcano (eruption in 1919) whose summit is just exposed at low tide. Gas bubbling, subsurface sonic activity, and <span class="hlt">venting</span> of <span class="hlt">hydrothermal</span> fluids with temperatures around 50ºC are known to occur on the summit at around 10 m depth, and ferruginous oxide deposits several mm thick are common. A multibeam bathymetric chart to 1000 m was prepared and deeper narrow-beam echo sounding show that Banua Wuhu is a parasitic feature on the north-western side of adjacent Mahenetang Island, also a volcanic construction, the combined edifice exceeding 3000 m in height. We recovered thoroughly altered porphyritc andesite containing disseminated pyrite and a carbonate-chlorite-clay mineral assemblage. In summary, while the IASSHA cruise located only a single but potentially significant example of modern seafloor <span class="hlt">hydrothermal</span> activity, we collected much valuable new geological and oceanographic data on two contrasted areas in northeastern Sulawesi that with on going post-cruise processing will greatly expand our knowledge of these regions. Binns and Permana Co-Chief Scientists</p> <div class="credits"> <p class="dwt_author">McConachy, T.; Binns, R.; Permana, H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">78</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41000727"> <span id="translatedtitle">Heat shock protein expression pattern (HSP70) in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We previously reported evidence of increased levels of DNA damage in the <span class="hlt">hydrothermal</span> mussel Bathymodiolus azoricus, which suggested that the species was not fully resistant to the natural toxicity of its deep-sea <span class="hlt">vent</span> environment. In the present study, HSP70 was used as a biomarker of sub-cellular stress. Differences in HSP70 expression pattern were observed between <span class="hlt">vent</span> <span class="hlt">sites</span>, typified by different</p> <div class="credits"> <p class="dwt_author">A. M. Pruski; D. R. Dixon</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">79</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/23426152"> <span id="translatedtitle">Tomography of bacteria–mineral associations within the deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp Rimicaris exoculata</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Rimicaris exoculata flourishes around deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> environments along the Mid-Atlantic Ridge (MAR). Epibiotic bacteria and minerals found within the branchial chamber of the shrimp are of interest in the search for the metabolic energy pathways sustaining shrimp swarms at the Rainbow <span class="hlt">vent</span> <span class="hlt">site</span> (MAR). Here we examine the three-dimensional (3D) relationships between epibionts and their associated minerals. The morphology</p> <div class="credits"> <p class="dwt_author">Louise Anderson; Sébastien Halary; Jean-Pierre Lechaire; Thomas Boudier; Ghislaine Frébourg; Sergio Marco; Magali Zbinden; Françoise Gaill</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">80</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/16537128"> <span id="translatedtitle">Identification of differentially expressed genes in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp Rimicaris exoculata exposed to heat stress</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The deep-sea <span class="hlt">vent</span> shrimp Rimicaris exoculata dominates the vagile megafauna at most <span class="hlt">vent</span> <span class="hlt">sites</span> along the Mid-Atlantic Ridge. This shrimp swarms around the hot end of the <span class="hlt">hydrothermal</span> biotope where temperature can exceed its critical maximal temperature (33–38.5±2°C). It may therefore be subjected to a thermal regime that is assumed to be stressful for animals. In this study, we used</p> <div class="credits"> <p class="dwt_author">Delphine Cottin; Bruce Shillito; Thomas Chertemps; Arnaud Tanguy; Nelly Léger; Juliette Ravaux</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_3");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' 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showDiv("page_6");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">81</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3695286"> <span id="translatedtitle">Characterizing the distribution and rates of microbial sulfate reduction at Middle Valley <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Few studies have directly measured sulfate reduction at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, and relatively little is known about how environmental or ecological factors influence rates of sulfate reduction in <span class="hlt">vent</span> environments. A better understanding of microbially mediated sulfate reduction in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystems may be achieved by integrating ecological and geochemical data with metabolic rate measurements. Here we present rates of microbially mediated sulfate reduction from three distinct <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in the Middle Valley <span class="hlt">vent</span> field along the Juan de Fuca Ridge, as well as assessments of bacterial and archaeal diversity, estimates of total biomass and the abundance of functional genes related to sulfate reduction, and in situ geochemistry. Maximum rates of sulfate reduction occurred at 90?°C in all three deposits. Pyrosequencing and functional gene abundance data revealed differences in both biomass and community composition among <span class="hlt">sites</span>, including differences in the abundance of known sulfate-reducing bacteria. The abundance of sequences for Thermodesulfovibro-like organisms and higher sulfate reduction rates at elevated temperatures suggests that Thermodesulfovibro-like organisms may have a role in sulfate reduction in warmer environments. The rates of sulfate reduction presented here suggest that—within anaerobic niches of <span class="hlt">hydrothermal</span> deposits—heterotrophic sulfate reduction may be quite common and might contribute substantially to secondary productivity, underscoring the potential role of this process in both sulfur and carbon cycling at <span class="hlt">vents</span>.</p> <div class="credits"> <p class="dwt_author">Frank, Kiana L; Rogers, Daniel R; Olins, Heather C; Vidoudez, Charles; Girguis, Peter R</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">82</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1992DSRA...39.1067V"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> ostracoda and faunal association in the deep sea</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Ostracod faunas from Pacific <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> include eucytherurine and pontocypridid Podocopa and are very similar to those previously recorded from experimental wood islands. Both <span class="hlt">vent</span> and wood-island ostracods may belong to a single deep-sea faunal association that is adapted to a eutrophic regime. This regime, which is quite distinct from normal deep-sea conditions, is probably widespread in the world's ocean, although individual manifestations tent to be localized and ephemeral.</p> <div class="credits"> <p class="dwt_author">van Harten, Dick</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">83</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41000993"> <span id="translatedtitle">Variation in physiological indicators in Bathymodiolus azoricus (Bivalvia: Mytilidae) at the Menez Gwen Mid-Atlantic Ridge deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span> within a year</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Bathymodiolus azoricus, thriving at Mid-Atlantic Ridge deep <span class="hlt">vents</span>,\\u000a benefits from a symbiosis with methane- and sulphide-oxidising (MOX and\\u000a SOX) bacteria, and feeds on particulate and dissolved organic matter. To\\u000a investigate the temporal evolution in their nutrition adult mussels were\\u000a collected from one location at the Menez Gwen <span class="hlt">vent</span> <span class="hlt">site</span> (817 m depth) on\\u000a four occasions between 2006 and 2007 and</p> <div class="credits"> <p class="dwt_author">Virginie Riou; Sebastien Duperron; Sebastien Halary; Frank Dehairs; Steven Bouillon; Ines Martins; Ana Colaco; Ricardo Serrao Santos</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">84</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013DSRI...74....1N"> <span id="translatedtitle">Discovery of a new <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> based on an underwater, high-resolution geophysical survey</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A new <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span> in the Southern Mariana Trough has been discovered using acoustic and magnetic surveys conducted by the Japan Agency for Marine-Earth Science and Technology's (JAMSTEC) autonomous underwater vehicle (AUV), Urashima. The high-resolution magnetic survey, part of a near-bottom geophysical mapping around a previously known <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span>, the Pika <span class="hlt">site</span>, during the YK09-08 cruise in June-July 2009, found that a clear magnetization low extends ˜500 m north from the Pika <span class="hlt">site</span>. Acoustic signals, suggesting <span class="hlt">hydrothermal</span> plumes, and 10 m-scale chimney-like topographic highs were detected within this low magnetization zone by a 120 kHz side-scan sonar and a 400 kHz multibeam echo sounder. In order to confirm the seafloor sources of the geophysical signals, seafloor observations were carried out using the deep-sea manned submersible Shinkai 6500 during the YK 10-10 cruise in August 2010. This discovered a new <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span> (12°55.30'N, 143°38.89'E; at a depth of 2922 m), which we have named the Urashima <span class="hlt">site</span>. This <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span> covers an area of approximately 300 m×300 m and consists of black and clear smoker chimneys, brownish-colored shimmering chimneys, and inactive chimneys. All of the fluids sampled from the Urashima and Pika <span class="hlt">sites</span> have chlorinity greater than local ambient seawater, suggesting subseafloor phase separation or leaching from rocks in the <span class="hlt">hydrothermal</span> reaction zone. End-member compositions of the Urashima and Pika fluids suggest that fluids from two different sources feed the two <span class="hlt">sites</span>, even though they are located on the same knoll and separated by only ˜500 m. We demonstrate that investigations on <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> located in close proximity to one another can provide important insights into subseafloor <span class="hlt">hydrothermal</span> fluid flow, and also that, while such <span class="hlt">hydrothermal</span> <span class="hlt">sites</span> are difficult to detect by conventional plume survey methods, high-resolution underwater geophysical surveys provide an effective means.</p> <div class="credits"> <p class="dwt_author">Nakamura, Kentaro; Toki, Tomohiro; Mochizuki, Nobutatsu; Asada, Miho; Ishibashi, Jun-ichiro; Nogi, Yoshifumi; Yoshikawa, Shuro; Miyazaki, Jun-ichi; Okino, Kyoko</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-04-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">85</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/16346061"> <span id="translatedtitle">Anaerobic spirochete from a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">An obligately anaerobic spirochete, designated strain GS-2, was selectively isolated from samples collected at a deep-sea (2,550 m) <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> of the Galapagos Rift ocean floor spreading center. The morphological and physiological characteristics of strain GS-2 resembled those of Spirochaeta strains. However, strain GS-2 failed to grow consistently in any liquid medium tested. In addition, strain GS-2 grew more slowly and to lower yields than other Spirochaeta species. The occurrence of obligately anaerobic bacteria in <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> indicates that the water in at least some of the <span class="hlt">vent</span> areas is anoxic. The presence of strain GS-2 shows that these areas are favorable for anaerobic marine spirochetes. PMID:16346061</p> <div class="credits"> <p class="dwt_author">Harwood, C S; Jannasch, H W; Canale-Parola, E</p> <p class="dwt_publisher"></p> <p class="publishDate">1982-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">86</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2000ECSS...51..627P"> <span id="translatedtitle">The Sponge Community of a Subtidal Area with <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span>: Milos Island, Aegean Sea</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Sponges were sampled by SCUBA diving at six subtidal rocky <span class="hlt">sites</span>, three of which were close to <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, a common feature on the sea-floor off the south-east coast of Milos. Twenty-five species (2 Calcarea and 23 Demospongiae) were found, few compared with the 589 recorded for the Mediterranean, but an important addition to the scant information on the sponge fauna of the Aegean Sea. The number of species found at <span class="hlt">vent</span> <span class="hlt">sites</span> was consistently higher than that found at non-<span class="hlt">vent</span> <span class="hlt">sites</span>, but no <span class="hlt">vent</span>-obligate species could be identified. However, Geodia cydonium and three species of Cliona ( C. copiosa, C. nigricans and C. rhodensis) showed a tendency to colonize <span class="hlt">vent</span> areas. The former might take advantage of increased silica availability, the latter of the enhanced deposition of carbonates near <span class="hlt">vents</span>. Substratum cover by sponges (estimated from wire-framed photographs of 0·7 m 2), varied greatly both among and within <span class="hlt">sites</span>, mostly according to slope. Most sponge species preferred vertical to overhanging, shaded substrata. Proximity to <span class="hlt">vents</span> seemed to have little or no influence on sponge cover, notwithstanding a primary effect on species diversity.</p> <div class="credits"> <p class="dwt_author">Pansini, M.; Morri, C.; Bianchi, C. N.</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">87</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3250512"> <span id="translatedtitle">The Discovery of New Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Communities in the Southern Ocean and Implications for Biogeography</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Since the first discovery of deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> along the Galápagos Rift in 1977, numerous <span class="hlt">vent</span> <span class="hlt">sites</span> and endemic faunal assemblages have been found along mid-ocean ridges and back-arc basins at low to mid latitudes. These discoveries have suggested the existence of separate biogeographic provinces in the Atlantic and the North West Pacific, the existence of a province including the South West Pacific and Indian Ocean, and a separation of the North East Pacific, North East Pacific Rise, and South East Pacific Rise. The Southern Ocean is known to be a region of high deep-sea species diversity and centre of origin for the global deep-sea fauna. It has also been proposed as a gateway connecting <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in different oceans but is little explored because of extreme conditions. Since 2009 we have explored two segments of the East Scotia Ridge (ESR) in the Southern Ocean using a remotely operated vehicle. In each segment we located deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> hosting high-temperature black smokers up to 382.8°C and diffuse <span class="hlt">venting</span>. The chemosynthetic ecosystems hosted by these <span class="hlt">vents</span> are dominated by a new yeti crab (Kiwa n. sp.), stalked barnacles, limpets, peltospiroid gastropods, anemones, and a predatory sea star. Taxa abundant in <span class="hlt">vent</span> ecosystems in other oceans, including polychaete worms (Siboglinidae), bathymodiolid mussels, and alvinocaridid shrimps, are absent from the ESR <span class="hlt">vents</span>. These groups, except the Siboglinidae, possess planktotrophic larvae, rare in Antarctic marine invertebrates, suggesting that the environmental conditions of the Southern Ocean may act as a dispersal filter for <span class="hlt">vent</span> taxa. Evidence from the distinctive fauna, the unique community structure, and multivariate analyses suggest that the Antarctic <span class="hlt">vent</span> ecosystems represent a new <span class="hlt">vent</span> biogeographic province. However, multivariate analyses of species present at the ESR and at other deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> globally indicate that <span class="hlt">vent</span> biogeography is more complex than previously recognised.</p> <div class="credits"> <p class="dwt_author">Rogers, Alex D.; Tyler, Paul A.; Connelly, Douglas P.; Copley, Jon T.; James, Rachael; Larter, Robert D.; Linse, Katrin; Mills, Rachel A.; Garabato, Alfredo Naveira; Pancost, Richard D.; Pearce, David A.; Polunin, Nicholas V. C.; German, Christopher R.; Shank, Timothy; Boersch-Supan, Philipp H.; Alker, Belinda J.; Aquilina, Alfred; Bennett, Sarah A.; Clarke, Andrew; Dinley, Robert J. J.; Graham, Alastair G. C.; Green, Darryl R. H.; Hawkes, Jeffrey A.; Hepburn, Laura; Hilario, Ana; Huvenne, Veerle A. I.; Marsh, Leigh; Ramirez-Llodra, Eva; Reid, William D. K.; Roterman, Christopher N.; Sweeting, Christopher J.; Thatje, Sven; Zwirglmaier, Katrin</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">88</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1988DSRA...35.1811F"> <span id="translatedtitle">Variation in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> clam, Calyptogen magnifica, at the Rose Garden <span class="hlt">vent</span> on the Galapagos spreading center</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Calyptogena magnifica occupy a relatively restricted habitat at the Rose Garden <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span> on the Galapagos Rift. These clams are found in areas with very low flow of <span class="hlt">vent</span> water and gain exposure to hydrogen sulfide by inserting their well-vascularized foot into cracks that contain this flow. <span class="hlt">Vent</span> water is undetectable around the siphons of many of the individuals, and they therefore probably take up sulfide through their foot, and oxygen and inorganic carbon through their gills. Age estimates indicate that the bulk of the recruitment of C. magnifica occured between 1971 and 1976. Isotopic evidence indicates that symbionts are the main source of both nutritional carbon and nitrogen for the clams, and that the symbionts assimilate both of these substrates from inorganic sources. Carbohydrate and protein in the clam soft tissues, as well as the elemental sulfur content of their gills, decrease with increasing clam size. There is only slight variation in most of the parameters measured, and none of the parameters show nearly the variation seen in the other <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> bivalve, Bathymodiolus thermophilus. However, several parameters, such as ?13C, condition index, and some bacterial enzyme activities, vary significantly with habitat.</p> <div class="credits"> <p class="dwt_author">Fisher, C. R.; Childress, J. J.; Arp, A. J.; Brooks, J. M.; Distel, D. L.; Dugan, J. A.; Felbeck, H.; Fritz, L. W.; Hessler, R. R.; Johnson, K. S.; Kennicutt, M. C.; Lutz, R. A.; Macko, S. A.; Newton, A.; Powell, M. A.; Somero, G. N.; Soto, T.</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-10-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">89</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003AGUFM.B12A0758P"> <span id="translatedtitle">Microbial Diversity at the Low-Temperature <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> of the Galapagos Rift</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> were discovered more than 20 years ago at the Galapagos Rift. However, no systematic assessment of the microbial diversity has been done at this historic <span class="hlt">site</span>. In May 2002, we revisited the Galapagos Rift, noted many changes at the former active <span class="hlt">sites</span> and discovered new <span class="hlt">vent</span> fields. The microbial diversity associated with water and rock samples was determined using a molecular phylogenetic approach based on the small subunit rRNA. Both typical <span class="hlt">vent</span> and non-<span class="hlt">vent</span> microbes were detected, such as epsilon- and gamma-Proteobacteria respectively. The archaeal diversity included members of the marine crenarchaeal group I, and euryarchaeal group II and III. Similar microbial diversity has been observed at other low-temperature deep-sea <span class="hlt">vent</span> <span class="hlt">sites</span> of the Juan de Fuca Ridge, Mid-Atlantic Ridge, and Loihi Seamount. Such communities are probably restricted to areas where low temperature fluids are discharged at low velocities. In these conditions, opportunistic seawater microbes may share the same ecological niches as <span class="hlt">vent</span> microorganisms. The presence of epsilon-Proteobacteria at the Galapagos Rift further confirm the global distribution of this group at deep-sea <span class="hlt">vents</span>.</p> <div class="credits"> <p class="dwt_author">Page, A.; Ward, N.; Shank, T. M.; Farhang, B.; Reysenbach, A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">90</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1995GMS....91...72H"> <span id="translatedtitle">The deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> community: An overview</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Few discoveries in science come as a complete shock. The discovery of the first <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> communities in the deep sea off the coast of Ecuador in the winter of 1977 astonished scientists around the world [Kaharl, 1990]. Entire communities of bizarre creatures were observed thriving in the so-called desert of the deep sea. While there is still much to learn about these geothermally-driven communities, we have gained a basic idea of their natural history.</p> <div class="credits"> <p class="dwt_author">Hessler, Robert R.; Kaharl, Victoria A.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">91</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/d8j01q78664x1881.pdf"> <span id="translatedtitle">Sulfide Oxidation across Diffuse Flow Zones of <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The sulfide (H2S\\/HS?) that is emitted from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> begins to oxidize abiotically with oxygen upon contact with ambient bottom water,\\u000a but the reaction kinetics are slow. Here, using in situ voltammetry, we report detection of the intermediate sulfur oxidation\\u000a products polysulfides [$$ {\\\\text{S}}_{\\\\text{x}}^{2 - } $$] and thiosulfate [$$ {\\\\text{S}}_{ 2} {\\\\text{O}}_{ 3}^{ 2- } $$], along with contextual</p> <div class="credits"> <p class="dwt_author">Amy Gartman; Mustafa Yücel; Andrew S. Madison; David W. Chu; Shufen Ma; Christopher P. Janzen; Erin L. Becker; Roxanne A. Beinart; Peter R. Girguis; George W. Luther</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">92</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002GeoRL..29.1744W"> <span id="translatedtitle">Ambient light emission from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> on the Mid-Atlantic Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A spectral imaging camera was used to observe light emission from high-temperature, deep-sea <span class="hlt">vents</span> at three <span class="hlt">hydrothermal</span> <span class="hlt">sites</span> on the Mid-Atlantic Ridge (MAR): Logatchev, Snake Pit, and Lucky Strike. Ambient light measured at these <span class="hlt">sites</span> is similar to that observed at <span class="hlt">sites</span> along the East Pacific Rise and the Juan de Fuca Ridge, with components from both thermal and non-thermal sources. The shrimp species Rimicaris exoculata, which is found on the MAR but not in the Eastern Pacific, possesses a unique photoreceptor capable of detecting low light levels. It is not yet known if R. exoculata ``sees'' <span class="hlt">vent</span> light. However, since the characteristics of <span class="hlt">vent</span> light appear to be unrelated to geographical location, the exclusion of R. exoculata from the Eastern Pacific is probably unrelated to differences in ambient light conditions.</p> <div class="credits"> <p class="dwt_author">White, Sheri N.; Chave, Alan D.; Reynolds, George T.; Van Dover, Cindy L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-08-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">93</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/20605205"> <span id="translatedtitle">Variation in physiological indicators in Bathymodiolus azoricus (Bivalvia: Mytilidae) at the Menez Gwen Mid-Atlantic Ridge deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span> within a year.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Bathymodiolus azoricus, thriving at Mid-Atlantic Ridge deep <span class="hlt">vents</span>, benefits from a symbiosis with methane- and sulphide-oxidising (MOX and SOX) bacteria, and feeds on particulate and dissolved organic matter. To investigate the temporal evolution in their nutrition adult mussels were collected from one location at the Menez Gwen <span class="hlt">vent</span> <span class="hlt">site</span> (817 m depth) on four occasions between 2006 and 2007 and studied using different techniques, including stable isotope analyses and FISH. Gill and mantle tissues delta13C and delta15N signatures varied by 2-3 per thousand during the year and these variations were linked to fluctuations in tissue condition index, C and N contents and SOX/MOX volume ratios as quantified by 3D-FISH. October and January mussels presented a particularly poor condition, possibly related with the prolonged summer period of low sea-surface primary production and/or with the stress of the transplant to acoustically retrievable cages for the October mussels, and with their reproductive state in January mussels, since they were spawning. Our results point to the possibility that May mussels benefited from a pulse of sinking sea-surface plankton material. Results underline the dependency of stable isotopic signatures on the physiological state of the mussel at the time of collection, and on the type of tissue analyzed. PMID:20605205</p> <div class="credits"> <p class="dwt_author">Riou, Virginie; Duperron, Sébastien; Halary, Sébastien; Dehairs, Frank; Bouillon, Steven; Martins, Inès; Colaço, Ana; Serrão Santos, Ricardo</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">94</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1992GeCoA..56.3643S"> <span id="translatedtitle">Chemistry of <span class="hlt">hydrothermal</span> solutions from Pele's <span class="hlt">Vents</span>, Loihi Seamount, Hawaii</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> fluids were sampled from Pele's <span class="hlt">Vents</span> on the summit of Loihi Seamount, an intraplate, hotspot volcano, on four occasions from February 1987 to September 1990. The warm (? 31°C) <span class="hlt">vent</span> solutions are enriched in dissolved Si, CO 2, H 2S, alkalinity, K +, Li +, Rb +, Ca 2+, Sr 2+, Ba 2+, Fe 2+, Mn 2+, NH 4+, and possibly Ni 2+, and depleted in SO 42-, O 2, Mg 2+, 87Sr /86Sr , NO 3-, and sometimes Cl - and Na + (calculated), relative to ambient seawater. Dissolved Si correlates linearly with sample temperature, suggesting that the solutions sampled from numerous <span class="hlt">vents</span> in the ~ 20 m diameter field have a common source and that Si can be used as a conservative tracer for mixing of the <span class="hlt">vent</span> fluids with ambient seawater. There are general similarities of the <span class="hlt">vent</span> waters with ridge-axis warm springs on the Galapagos Rift and Axial Seamount, but also striking differences: very high total dissolved CO 2 (> 200 mmol/kg), high alkalinity (> 8 meq/kg) and dissolved Fe 2+ (almost 1 mmol/kg), and relatively low pH (~ 4.2-4.4 estimated, in situ, sws) and dissolved H 2S (several ?mol/kg). The Mg 2+ and SO 42- data are inconsistent with the "Galapagos model" proposed for the warm springs at 86°W, Galapagos Rift, whereby the warm fluids result from sub-seafloor mixing of a high-temperature (~ 350°C) <span class="hlt">hydrothermal</span> endmember with essentially unaltered seawater. The variable Cl - depletions in the <span class="hlt">vent</span> fluids, however, suggest that the warm <span class="hlt">vent</span> fluids do contain a high-temperature (> 200°C) component. The fluid history can be qualitatively described by a modified "Galapagos model" which includes the overprint of reactions resulting from the addition of juvenile CO 2 and SO 2 to the circulating fluids; the CO 2 attacks the basalt releasing metal cations, HCO 3- and possibly Si into solution, and the SO 2 is hydrolyzed to SO 42-. These juvenile inputs likely reflect the shallow, hotspot setting of this <span class="hlt">hydrothermal</span> system. A simple quantitative fluidhistory model is considered and shown to be consistent with mass-balance constraints and saturationstate calculations, which suggest that the Si concentration of the fluids may be controlled by amorphous silica saturation at ~ 31°C. Observed temporal variations in fluid composition between expeditions - specifically, in Cl -, AT, CT, Na + (calculated), Mg 2+, Ca 2+, Sr 2+, 87Sr /86Sr , Fe 2+, Mn 2+ and perhaps NH 4+, relative to Si - are, excepting Mg 2+, 87Sr /86Sr , and Mn 2+, consistent with the effects of variable phase segregation at the proposed high-temperature endmember.</p> <div class="credits"> <p class="dwt_author">Sedwick, P. N.; McMurtry, G. M.; Macdougall, J. D.</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-10-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">95</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFMOS13A1715S"> <span id="translatedtitle">Biodiversity and biogeography of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> species in the western Pacific: a biological perspective of TAIGA project</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> are scientifically interesting environments where strong interactions of geology, chemistry, and biology can be observed. The <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> are geologically controlled in association with magmatic activities while diversity of chemicals (such as hydrogen sulfide) contained in <span class="hlt">hydrothermal</span> fluid is controlled by geochemical interaction between heated seawater and surrounding rocks. In addition to those geological and chemical characters of <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, high biomasses of chemosynthetic community have been known around many <span class="hlt">vents</span> since the first discovery in the 1970s. To understand the unique system and diversity of biological communities associated with <span class="hlt">vents</span> is highly valuable in geological, chemical, and biological sciences. As an activity of the research project "TAIGA (Trans-crustal Advection & In-situ bio-geochemical processes of Global sub-seafloor Aquifer)" (Representative: Tetsuro Urabe, Department of Earth & Planetary Science, the University of Tokyo), we analyzed population structures and connectivity as well as larval ecology of various <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> species in the Okinawa Trough and the Mariana Trough in an attempt to estimate faunal transitional history associated with <span class="hlt">hydrothermal</span> activities. The specimens analyzed in the present study were collected by R/V Yokosuka with manned submersible Shinkai6500 and R/V Natsushima with ROV Hyper-Dolphin during YK10-11 and NT11-20 cruises, respectively. In the Mariana Trough (YK10-11), benthic and planktonic faunas were investigated by multiple sampling and use of plankton samplers in three <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> (Snail, Archaean, and Urashima-Pika fields). Faunal compositions were then compared as well as size compositions and genetic diversities of major <span class="hlt">vent</span> species among local populations. In the Okinawa Trough (NT11-20), multiple quantitative sampling was made with simultaneous environmental measurements at more than two <span class="hlt">sites</span> in five <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> (Minami-Ensei Knoll, Yoron Knoll, Izena Hole, Irabu Knoll, and Hatoma Knoll). Among the local populations, biodiversities were analyzed and compared in consideration of abiotic environmental factors including temperature and chemical compositions. Ecological aspects of larvae were examined by laboratory experiments in addition to the genetic approaches and population dynamics. Preliminary results of the ongoing studies suggested that the biodiversity of <span class="hlt">vents</span> may be consistent with geographical history. By accumulating results of diversified approaches, we progress our study to reveal not only biological characters but also geological and chemical aspects of those <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</p> <div class="credits"> <p class="dwt_author">Seo, M.; Watanabe, H.; Nakamura, M.; Sasaki, T.; Ogura, T.; Yahagi, T.; Takahashi, Y.; Ishibashi, J.; Kojima, S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">96</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/56583620"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> fields and chemosynthetic biota on the world's deepest seafloor spreading centre</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The Mid-Cayman spreading centre is an ultraslow-spreading ridge in the Caribbean Sea. Its extreme depth and geographic isolation from other mid-ocean ridges offer insights into the effects of pressure on <span class="hlt">hydrothermal</span> <span class="hlt">venting</span>, and the biogeography of <span class="hlt">vent</span> fauna. Here we report the discovery of two <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields on the Mid-Cayman spreading centre. The Von Damm <span class="hlt">Vent</span> Field is located</p> <div class="credits"> <p class="dwt_author">Bramley J. Murton; Kate Stansfield; Paul A. Tyler; Christopher R. German; Cindy L. Van Dover; Diva Amon; Maaten Furlong; Nancy Grindlay; Nicholas Hayman; Veit Hühnerbach; Maria Judge; Tim Le Bas; Stephen McPhail; Alexandra Meier; Ko-ichi Nakamura; Verity Nye; Miles Pebody; Rolf B. Pedersen; Sophie Plouviez; Carla Sands; Roger C. Searle; Peter Stevenson; Sarah Taws; Sally Wilcox; Douglas P. Connelly; Jonathan T. Copley</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">97</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://aem.asm.org/cgi/reprint/67/1/110.pdf"> <span id="translatedtitle">Characterization of a Novel Spirochete Associated with the <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Polychaete Annelid, Alvinella pompejana</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">A highly integrated, morphologically diverse bacterial community is associated with the dorsal surface of Alvinella pompejana, a polychaetous annelid that inhabits active high-temperature deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> along the East Pacific Rise (EPR). Analysis of a previously prepared bacterial 16S ribosomal DNA (rDNA) library identified a spirochete most closely related to an endosymbiont of the oligochete Olavius loisae. This spirochete</p> <div class="credits"> <p class="dwt_author">BARBARA J. CAMPBELL; S. CRAIG CARY</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">98</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/49025345"> <span id="translatedtitle">Ecology and Biogeography of the <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Fauna of the Mid-Atlantic Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Six <span class="hlt">sites</span> of <span class="hlt">hydrothermal</span> activity with associated specialized fauna have been studied, lying between 14°45? and 37°51?N along the Mid-Atlantic Ridge (MAR). To date about 100 species have been recorded, but the number increases with each expedition. There are common patterns in the distribution of the animals. The community organization usually changes with distance from the centre of <span class="hlt">venting</span>, and</p> <div class="credits"> <p class="dwt_author">A. V. Gebruk; S. V. Galkin; A. L. Vereshchaka; L. I. Moskalev; A. J. Southward</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">99</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFM.B41F..03H"> <span id="translatedtitle">Subseafloor Microbial Life in <span class="hlt">Venting</span> Fluids from the Mid Cayman Rise <span class="hlt">Hydrothermal</span> System</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In hard rock seafloor environments, fluids emanating from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> are one of the best windows into the subseafloor and its resident microbial community. The functional consequences of an extensive population of microbes living in the subseafloor remains unknown, as does our understanding of how these organisms interact with one another and influence the biogeochemistry of the oceans. Here we report the abundance, activity, and diversity of microbes in <span class="hlt">venting</span> fluids collected from two newly discovered deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> along the ultra-slow spreading Mid-Cayman Rise (MCR). Fluids for geochemical and microbial analysis were collected from the Von Damm and Piccard <span class="hlt">vent</span> fields, which are located within 20 km of one another, yet have extremely different thermal, geological, and depth regimes. Geochemical data indicates that both fields are highly enriched in volatiles, in particular hydrogen and methane, important energy sources for and by-products of microbial metabolism. At both <span class="hlt">sites</span>, total microbial cell counts in the fluids ranged in concentration from 5 x 10 4 to 3 x 10 5 cells ml-1 , with background seawater concentrations of 1-2 x 10 4 cells ml-1 . In addition, distinct cell morphologies and clusters of cells not visible in background seawater were seen, including large filaments and mineral particles colonized by microbial cells. These results indicate local enrichments of microbial communities in the <span class="hlt">venting</span> fluids, distinct from background populations, and are consistent with previous enumerations of microbial cells in <span class="hlt">venting</span> fluids. Stable isotope tracing experiments were used to detect utilization of acetate, formate, and dissolve inorganic carbon and generation of methane at 70 °C under anaerobic conditions. At Von Damm, a putatively ultra-mafic hosted <span class="hlt">site</span> located at ~2200 m with a maximum temperature of 226 °C, stable isotope tracing experiments indicate methanogenesis is occurring in most fluid samples. No activity was detected in Piccard <span class="hlt">vent</span> fluids, a basalt-hosted black smoker <span class="hlt">site</span> located at ~4950 m with a maximum temperature of 403 °C. However, hyperthermophilic and thermophilic heterotrophs of the genus Thermococcus were isolated from Piccard <span class="hlt">vent</span> fluids, but not Von Damm. These obligate anaerobes, growing optimally at 55-90 °C, are ubiquitous at <span class="hlt">hydrothermal</span> systems and serve as a readily cultivable indicator organism of subseafloor populations. Finally, molecular analysis of <span class="hlt">vent</span> fluids is on-going and will define the microbial population structure in this novel ecosystem and allow for direct comparisons with other deep-sea and subsurface habitats as part of our continuing efforts to explore the deep microbial biosphere on Earth.</p> <div class="credits"> <p class="dwt_author">Huber, J. A.; Reveillaud, J.; Reddington, E.; McDermott, J. M.; Sylva, S. P.; Breier, J. A.; German, C. R.; Seewald, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">100</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/21966914"> <span id="translatedtitle">Dual symbiosis of the <span class="hlt">vent</span> shrimp Rimicaris exoculata with filamentous gamma- and epsilonproteobacteria at four Mid-Atlantic Ridge <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The shrimp Rimicaris exoculata from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> on the Mid-Atlantic Ridge (MAR) harbours bacterial epibionts on specialized appendages and the inner surfaces of its gill chamber. Using comparative 16S rRNA sequence analysis and fluorescence in situ hybridization (FISH), we examined the R. exoculata epibiosis from four <span class="hlt">vents</span> <span class="hlt">sites</span> along the known distribution range of the shrimp on the MAR. Our results show that R. exoculata lives in symbiosis with two types of filamentous epibionts. One belongs to the Epsilonproteobacteria, and was previously identified as the dominant symbiont of R. exoculata. The second is a novel gammaproteobacterial symbiont that belongs to a clade consisting exclusively of sequences from epibiotic bacteria of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> animals, with the filamentous sulfur oxidizer Leucothrix mucor as the closest free-living relative. Both the epsilon- and the gammaproteobacterial symbionts dominated the R. exoculata epibiosis at all four MAR <span class="hlt">vent</span> <span class="hlt">sites</span> despite striking differences between <span class="hlt">vent</span> fluid chemistry and distances between <span class="hlt">sites</span> of up to 8500 km, indicating that the symbiosis is highly stable and specific. Phylogenetic analyses of two mitochondrial host genes showed little to no differences between hosts from the four <span class="hlt">vent</span> <span class="hlt">sites</span>. In contrast, there was significant spatial structuring of both the gamma- and the epsilonproteobacterial symbiont populations based on their 16S rRNA gene sequences that was correlated with geographic distance along the MAR. We hypothesize that biogeography and host-symbiont selectivity play a role in structuring the epibiosis of R. exoculata. PMID:21966914</p> <div class="credits"> <p class="dwt_author">Petersen, Jillian M; Ramette, Alban; Lott, Christian; Cambon-Bonavita, Marie-Anne; Zbinden, Magali; Dubilier, Nicole</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-08-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_4");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return 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showDiv("page_7");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">101</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011AGUFMOS11B1500E"> <span id="translatedtitle">Multiple sulfur isotope composition of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> precipitates in western Pacific</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Seafloor <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> are the most suitable places to investigate the interactions between the ocean and lithosphere because of their fast, active, and visible characteristics in addition to having rich repositories of natural resources such as metallic minerals. Recent development in the analytical technique of multiple sulfur isotopes has led to a growing interest in sulfur tracing in geochemical processes as well as an expanded understanding of sulfur systematics. By process-specific characteristics of the multiple sulfur isotope system, current seafloor <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> sulfides from mid-oceanic ridges have shown isotope fractionation following the mixing of basaltic sulfide and seawater sulfate in the multiple sulfur isotope system. We report results for sulfur isotopes (32S, 33S, 34S) of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> precipitates from the Eastern Manus Basin, the North Fiji Basin, the Northeastern Lau basin, and Tonga arc in the southwestern Pacific boundary. We analyzed ?34S and ?33S values using a continuous flow - isotope ratio mass spectrometer. The ?34S values are similar to those from previous studies in western pacific areas while the ?33S values show wide ranges which may depend on the degree of disequilibrium. Most pyrite samples are higher in ?33S values than those of coexisting chalcopyrite due to fluid evolution during <span class="hlt">hydrothermal</span> circulation. Our result also conforms to the trend of seafloor <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> sulfides from the mid-oceanic ridge. However, Susu Knolls had anomalously high ?33S values above 33? = 0.515, which might indicate different processes of evolution in the multiple sulfur isotope system.</p> <div class="credits"> <p class="dwt_author">Eom, J.; Lee, I.; Kim, J.; Moon, J.; Lee, S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">102</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2006DSRI...53.1363Z"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> meiobenthos associated with mytilid mussel aggregations from the Mid-Atlantic Ridge and the East Pacific Rise</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> occur along the mid-ocean ridges and back-arc basins around the globe. There are very few community analyses of <span class="hlt">vent</span> meiobenthos. The central objectives of this study were to identify and quantify for the first time the entire metazoan meiobenthic community associated with mussel aggregations of Bathymodiolus thermophilus Kenk and Wilson, 1985 from the EPR, 11°N and of Bathymodiolus puteoserpentis Cosel et al., 1994 from the Mid-Atlantic Ridge (MAR), 23°N. Using a quantitative sampling method, abundance, biomass, sex ratio, species richness, diversity, evenness, and trophic structure were studied based on three samples from each <span class="hlt">site</span>. Meiobenthic abundance in each sample was unexpectedly low, but similar between <span class="hlt">sites</span>. The community was composed of nematodes, copepods, ostracods, and mites, with a total of 24 species at EPR <span class="hlt">vents</span>, and 15 species at MAR <span class="hlt">vents</span>. While most copepod species were <span class="hlt">vent</span> endemics within the family Dirivultidae, nematodes and harpacticoid copepods belonged to generalist genera, which occur at a variety of habitats and are not restricted to <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> or the deep sea. The meiobenthos of <span class="hlt">hydrothermal-vent</span> mussel beds constitutes a unique community unlike those of other sulfidic habitats, including the thiobios of shallow-water sediments and the meiobenthos of deep-sea, cold-seep sediments. The trophic structure was dominated by primary consumers, mainly deposit feeders, followed by parasites. Predatory meiofaunal species were absent.</p> <div class="credits"> <p class="dwt_author">Zekely, J.; Van Dover, C. L.; Nemeschkal, H. L.; Bright, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-08-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">103</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009AGUFMOS12A..03D"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> flow and turbulence measurements with acoustic scintillation instrumentation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Acoustically derived measurements of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> flow and turbulence were obtained from the active black smoker Dante in the Main Endeavour <span class="hlt">vent</span> field, using scintillation analysis from one-way transmissions. The scintillation transmitter and receiver array formed a 93 m acoustic path through the buoyant plume 20 m above the structure. The acoustic path was parallel to the valley sidewall where the M2 tidal currents are approximately aligned along ridge due to topographic steering by the valley walls and hence most of the plume displacement is expected to occur along the acoustic path. On one deployment, data were collected for 6.5 weeks and vertical velocities range from 0.1 to 0.2 m/s showing a strong dependence on the spring/neap tidal cycle. The refractive index fluctuations which can be paramaterized in terms of the root-mean-square temperature fluctuations also shows a strong tidal modulation during spring tide.</p> <div class="credits"> <p class="dwt_author">di Iorio, D.; Xu, G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">104</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=106600"> <span id="translatedtitle">Comparison of a New Thiomicrospira Strain from the Mid-Atlantic Ridge with Known <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Isolates†</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">A new autotrophic Thiomicrospira strain, MA-3, was isolated from the surface of a polymetal sulfide deposit collected at a Mid-Atlantic Ridge <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span>. The DNA homology among three <span class="hlt">vent</span> isolates, Thiomicrospira crunogena, Thiomicrospira sp. strain L-12, and Thiomicrospira sp. strain MA-3, was 99.3% or higher, grouping them as the same species, T. crunogena (type strain, ATCC 35932). The fact that T. crunogena and Thiomicrospira sp. strain L-12 were isolated from Pacific <span class="hlt">vent</span> <span class="hlt">sites</span> demonstrates a cosmopolitan distribution of this species.</p> <div class="credits"> <p class="dwt_author">Wirsen, C. O.; Brinkhoff, T.; Kuever, J.; Muyzer, G.; Molyneaux, S.; Jannasch, H. W.</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">105</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014EGUGA..1616710Y"> <span id="translatedtitle">Dynamic drivers of a shallow-water <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecogeochemical system (Milos, Eastern Mediterranean)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Shallow-water <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> share many characteristics with their deep-sea analogs. However, despite ease of access, much less is known about the dynamics of these systems. Here, we report on the spatial and temporal chemical variability of a shallow-water <span class="hlt">vent</span> system at Paleochori Bay, Milos Island, Greece, and on the bacterial and archaeal diversity of associated sandy sediments. Our multi-analyte voltammetric profiles of dissolved O2 and <span class="hlt">hydrothermal</span> tracers (e.g. Fe2+, FeSaq, Mn2+) on sediment cores taken along a transect in <span class="hlt">hydrothermally</span> affected sediments indicate three different areas: the central <span class="hlt">vent</span> area (highest temperature) with a deeper penetration of oxygen into the sediment, and a lack of dissolved Fe2+ and Mn2+; a middle area (0.5 m away) rich in dissolved Fe2+ and Mn2+ (exceeding 2 mM) and high free sulfide with potential for microbial sulfide oxidation as suggested by the presence of white mats at the sediment surface; and, finally, an outer rim area (1-1.5 m away) with lower concentrations of Fe2+ and Mn2+ and higher signals of FeSaq, indicating an aged <span class="hlt">hydrothermal</span> fluid contribution. In addition, high-frequency temperature series and continuous in situ H2S measurements with voltammetric sensors over a 6-day time period at a distance 0.5 m away from the <span class="hlt">vent</span> center showed substantial temporal variability in temperature (32 to 46 ºC ) and total sulfide (488 to 1329 µM) in the upper sediment layer. Analysis of these data suggests that tides, winds, and abrupt geodynamic events generate intermittent mixing conditions lasting for several hours to days. Despite substantial variability, the concentration of sulfide available for chemoautotrophic microbes remained high. These findings are consistent with the predominance of Epsilonproteobacteria in the <span class="hlt">hydrothermally</span> influenced sediments Diversity and metagenomic analyses on sediments and biofilm collected along a transect from the center to the outer rim of the <span class="hlt">vent</span> provide further insights on the metabolic activities and the environmental factors shaping these microbial communities . Both bacterial and archaeal diversity changed along the transect as well as with sediment depth, in line with the geochemical measurements. Beside the fact that it harbors an unexpected diversity of yet undescribed bacteria and archaea, this <span class="hlt">site</span> is also a relevant model to investigate the link between ecological and abiotic dynamics in such instable <span class="hlt">hydrothermal</span> environments. Our results provide evidence for the importance of transient geodynamic and hydrodynamic events in the dynamics and distribution of chemoautotrophic communities in the <span class="hlt">hydrothermally</span> influenced sediments of Paleochori Bay.</p> <div class="credits"> <p class="dwt_author">Yücel, Mustafa; Sievert, Stefan; Giovanelli, Donato; Foustoukos, Dionysis; DeForce, Emelia; Thomas, François; Vetriani, Constantino; Le Bris, Nadine</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">106</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/48807008"> <span id="translatedtitle">Spatial structures of <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and <span class="hlt">vent</span>-associated megafauna in the back-arc basin system of the Okinawa Trough, western Pacific</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Spatial patterns and morphology of <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and the occurrence of <span class="hlt">vent</span>-associated megafauna were investigated in\\u000a the back-arc basin system of the Okinawa Trough, western Pacific. Amongst <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields located on the rising slopes\\u000a to the NE and S of the basin, the Iheya North area has been subjected to a series of intensive diving surveys. <span class="hlt">Hydrothermal</span>\\u000a <span class="hlt">vents</span> demonstrated</p> <div class="credits"> <p class="dwt_author">M. Tokeshi</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">107</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/52868012"> <span id="translatedtitle">Tomography of Bacteria-Mineral Associations Within the Deep sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Shrimp Rimicaris exoculata</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The chemical and temperature conditions around deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> are both dynamic and extreme, yet the shrimp Rimicaris exoculata flourishes around these environments on the Mid-Atlantic Ridge (MAR) . The epibiotic bacteria and minerals found within the branchial chamber of the shrimp are of great interest in the search for a chemical model for the Rainbow MAR <span class="hlt">hydrothermal</span> <span class="hlt">vent</span></p> <div class="credits"> <p class="dwt_author">L. Anderson; J. Lechaire; G. Frebourg; T. Boudier; M. Zbinden; F. Gaill</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">108</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ifremer.fr/docelec/doc/2006/publication-2305.pdf"> <span id="translatedtitle">Bioaccumulation of Hg, Cu, and Zn in the Azores triple junction <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields food web</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In this work, mercury (Hg), copper (Cu) and zinc (Zn) concentrations and tissue distribution are determined in seven benthic invertebrates species (the key species) from the Mid Atlantic Ridge (MAR) <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields. The samples were collected from three <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields - Menez Gwen, 840 m; Lucky Strike, 1700 m and Rainbow, 2300 m - near the Azores Triple</p> <div class="credits"> <p class="dwt_author">A. Colaço; P. Bustamante; Y. Fouquet; R. Serrão-Santos</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">109</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1618913"> <span id="translatedtitle">Occurrence and recent long-distance dispersal of deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimps</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and methane seeps are extreme environments that have a high concentration of hydrogen sulphide. However, abundant unique invertebrates including shrimps of the family Bresiliidae have been found in such environments. The bresiliid shrimps are believed to have radiated in the Miocene (less than 20?Myr); however, the period when and the mechanisms by which they dispersed across the <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and cold seeps in oceans worldwide have not been clarified. In the present study, we collected the deep-sea blind shrimp Alvinocaris longirostris from the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span> in the Okinawa Trough and carried out the first investigation of the 18S rRNA gene of a bresiliid shrimp. The phylogenetic analysis revealed that the bresiliid shrimp is situated at an intermediate lineage within the infraorder Caridea and shows monophyly with palaemonid shrimps, which live in shallow sea and freshwater. Furthermore, the mitochondrial cytochrome oxidase I (COI) gene sequences were analysed to determine the phylogenetic relationship with known bresiliid shrimps. A. longirostris of the Okinawa Trough had two haplotypes of the COI gene, one of which was identical to the Alvinocaris sp. of the cold seeps in Sagami Bay. These results indicate that a long-distance dispersal of A. longirostris occurred possibly within the last 100?000 years.</p> <div class="credits"> <p class="dwt_author">Tokuda, Gaku; Yamada, Akinori; Nakano, Kazuma; Arita, Nao; Yamasaki, Hideo</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">110</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17148377"> <span id="translatedtitle">Occurrence and recent long-distance dispersal of deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimps.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and methane seeps are extreme environments that have a high concentration of hydrogen sulphide. However, abundant unique invertebrates including shrimps of the family Bresiliidae have been found in such environments. The bresiliid shrimps are believed to have radiated in the Miocene (less than 20 Myr); however, the period when and the mechanisms by which they dispersed across the <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and cold seeps in oceans worldwide have not been clarified. In the present study, we collected the deep-sea blind shrimp Alvinocaris longirostris from the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span> in the Okinawa Trough and carried out the first investigation of the 18S rRNA gene of a bresiliid shrimp. The phylogenetic analysis revealed that the bresiliid shrimp is situated at an intermediate lineage within the infraorder Caridea and shows monophyly with palaemonid shrimps, which live in shallow sea and freshwater. Furthermore, the mitochondrial cytochrome oxidase I (COI) gene sequences were analysed to determine the phylogenetic relationship with known bresiliid shrimps. A. longirostris of the Okinawa Trough had two haplotypes of the COI gene, one of which was identical to the Alvinocaris sp. of the cold seeps in Sagami Bay. These results indicate that a long-distance dispersal of A. longirostris occurred possibly within the last 100,000 years. PMID:17148377</p> <div class="credits"> <p class="dwt_author">Tokuda, Gaku; Yamada, Akinori; Nakano, Kazuma; Arita, Nao; Yamasaki, Hideo</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-06-22</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">111</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/51952637"> <span id="translatedtitle">Characterization of Dissolved Organic Matter from Deep-sea Floor <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> in South Mariana Backarc Spreading Center</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In South Mariana Backarc Spreading Center, a few active <span class="hlt">hydrothermal</span> fields are located. We investigated a characterization of dissolved organic matter (DOM) from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in this area, in order to clarify the biosphere beneath deep-sea floor. Hot water sample was collected from a drilled hole (APM01 located in Fryer <span class="hlt">site</span>, 12o 55.22fN, 143o 37.16fE, depth 2850m) during the ROPOS\\/TN167A</p> <div class="credits"> <p class="dwt_author">F. Kitajima; T. Yamanaka</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">112</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2007GeCoA..71.1170O"> <span id="translatedtitle">S-33 constraints on the seawater sulfate contribution in modern seafloor <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> sulfides</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Sulfide sulfur in mid-oceanic ridge <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> is derived from leaching of basaltic-sulfide and seawater-derived sulfate that is reduced during high temperature water rock interaction. Conventional sulfur isotope studies, however, are inconclusive about the mass-balance between the two sources because 34S/ 32S ratios of <span class="hlt">vent</span> fluid H 2S and chimney sulfide minerals may reflect not only the mixing ratio but also isotope exchange between sulfate and sulfide. Here, we show that high-precision analysis of S-33 can provide a unique constraint because isotope mixing and isotope exchange result in different ? 33S (?? 33S-0.515 ? 34S) values of up to 0.04‰ even if ? 34S values are identical. Detection of such small ? 33S differences is technically feasible by using the SF 6 dual-inlet mass-spectrometry protocol that has been improved to achieve a precision as good as 0.006‰ (2 ?). Sulfide minerals (marcasite, pyrite, chalcopyrite, and sphalerite) and <span class="hlt">vent</span> H 2S collected from four active seafloor <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span>, East Pacific Rise (EPR) 9-10°N, 13°N, and 21°S and Mid-Atlantic Ridge (MAR) 37°N yield ? 33S values ranging from -0.002 to 0.033 and ? 34S from -0.5‰ to 5.3‰. The combined ? 34S and ? 33S systematics reveal that 73 to 89% of <span class="hlt">vent</span> sulfides are derived from leaching from basaltic sulfide and only 11 to 27% from seawater-derived sulfate. Pyrite from EPR 13°N and marcasite from MAR 37°N are in isotope disequilibrium not only in ? 34S but also in ? 33S with respect to associated sphalerite and chalcopyrite, suggesting non-equilibrium sulfur isotope exchange between seawater sulfate and sulfide during pyrite precipitation. Seafloor <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> sulfides are characterized by low ? 33S values compared with biogenic sulfides, suggesting little or no contribution of sulfide from microbial sulfate reduction into <span class="hlt">hydrothermal</span> sulfides at sediment-free mid-oceanic ridge systems. We conclude that 33S is an effective new tracer for interplay among seawater, oceanic crust and microbes in subseafloor <span class="hlt">hydrothermal</span> sulfur cycles.</p> <div class="credits"> <p class="dwt_author">Ono, Shuhei; Shanks, Wayne C.; Rouxel, Olivier J.; Rumble, Douglas</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">113</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17014490"> <span id="translatedtitle">Off-axis symbiosis found: Characterization and biogeography of bacterial symbionts of Bathymodiolus mussels from Lost City <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Organisms at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> inhabit discontinuous chemical 'islands' along mid-ocean ridges, a scenario that may promote genetic divergence among populations. The 2003 discovery of mussels at the Lost City <span class="hlt">Hydrothermal</span> Field provided a means of evaluating factors that govern the biogeography of symbiotic bacteria in the deep sea. The unusual chemical composition of <span class="hlt">vent</span> fluids, the remote location, and paucity of characteristic <span class="hlt">vent</span> macrofauna at the <span class="hlt">site</span>, raised the question of whether microbial symbioses existed at the extraordinary Lost City. If so, how did symbiotic bacteria therein relate to those hosted by invertebrates at the closest known <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> along the Mid-Atlantic Ridge (MAR)? To answer these questions, we performed microscopic and molecular analyses on the bacteria found within the gill tissue of Bathymodiolus mussels (Mytilidae, Bathymodiolinae) that were discovered at the Lost City. Here we show that Lost City mussels harbour chemoautotrophic and methanotrophic endosymbionts simultaneously. Furthermore, populations of the chemoautotrophic symbionts from the Lost City and two <span class="hlt">sites</span> along the MAR are genetically distinct from each other, which suggests spatial isolation of bacteria in the deep sea. These findings provide new insights into the processes that drive diversification of bacteria and evolution of symbioses at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. PMID:17014490</p> <div class="credits"> <p class="dwt_author">DeChaine, Eric G; Bates, Amanda E; Shank, Timothy M; Cavanaugh, Colleen M</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">114</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003EAEJA....12021P"> <span id="translatedtitle">Sediment volcanoes and <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> complexes in pierced sedimentary basins</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Sedimentary basins with a considerable amount of piercement structures can be classified as pierced basins. Piercement structures include <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> complexes and mud volcanoes. The need to distinguish between sedimentary basins with and without significant amounts of piercement structures arise when considering the importance of these structures for the basin hydrology. We have studied sedimentary basins in South Africa (the Karoo basin), in Azerbaijan (the South Caspian basin), and in the Norwegian Sea (the Vøring and Møre basins) to characterize and constrain the effect of piercing processes. Our approach integrates seismic data, fieldwork, well studies, petrography, geochemistry, and numerical modelling. We have mapped and studied several hundred <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> complexes in the Karoo, Vøring and Møre basins. These piercement structures were formed as a consequence of intrusions of magmatic melt in sills and dikes. Numerical modelling suggest that creation of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> complexes may partly be related to overpressure generation as a consequence of boiling of pore fluids and hydrofracturing on a very short timescale after sill emplacement (10's of years). Seep carbonates, veins with petroleum, and mounds above the <span class="hlt">vent</span> complexes suggest that the structures act as permeability zones after their formation. Several hundred active mud volcanoes are located in Azerbaijan. The tectonics in this region is very dynamic, with extreme sediment accumulation (5 km in 5 Ma). The mud volcanoes are commonly located on anticlines and are associated with petroleum reservoirs. The formation of these piercement structures is related to overpressure generated by teconic forces and maturation. In summary, piercement structures are present both in volcanic and non-volcanic sedimentary basins. However, the composition of the piercement structures is similar in both basin settings, suggesting that they are formed by similar physical processes. Boiling of pore fluids is important in volcanic basins, as the volcanic intrusions heat the pore fluids in the sedimentary strata, whereas the piercing process is controlled by overpressure resulting from factors such as rapid burial of clays, decomposition of organic material, and tectonic compression in non-volcanic basins.</p> <div class="credits"> <p class="dwt_author">Planke, S.; Svensen, H.; Jamtveit, B.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-04-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">115</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://atiniui.nhm.org/pdfs/10203/10203.pdf"> <span id="translatedtitle">A new species of the shrimp genus Chorocaris (Decapoda: Caridea: Alvinocarididae) from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in the eastern Pacific Ocean</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Chorocaris paulexa, new species, the first member of the genus Chorocaris Martin & Hessler, 1990 reported from the eastern Pacific, is de­ scribed based primarily on two specimens, one of which is ovigerous, collected by the DSV Alvin at the Homer <span class="hlt">hydrothermal</span> (black smoker) <span class="hlt">vent</span> <span class="hlt">site</span> (17°S) on the southern East Pacific Rise (SEPR). Seven additional (non-type) speci­ mens from</p> <div class="credits"> <p class="dwt_author">Joel W. Martin; Timothy M. Shank</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">116</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014EGUGA..16.3929B"> <span id="translatedtitle">The influence of <span class="hlt">vent</span> fluid chemistry on trophic structure at two deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields on the Mid-Cayman Rise</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The two known deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields along the Mid-Cayman Rise are separated by a distance of only 21 km, yet their chemistry and faunal diversity are distinct. The deeper of the two <span class="hlt">vent</span> fields, Piccard (with active <span class="hlt">venting</span> from Beebe <span class="hlt">Vents</span>, Beebe Woods and Beebe Sea), at 4980 m is basalt hosted. The shallower <span class="hlt">vent</span> field, Von Damm, at 2300 m appears to have an ultramafic influence. The Von Damm <span class="hlt">vent</span> field can be separated into two <span class="hlt">sites</span>: The Spire and The Tubeworm Field. The dominant <span class="hlt">vent</span> fluids at the Tubeworm Field are distinct from those at the Spire, as a result of fluid modification in the sub-surface. Von Damm and Piccard <span class="hlt">vent</span> fields support abundant invertebrates, sharing the same biomass-dominant shrimp species, Rimicaris hybisae. Although there are some other shared species (squat lobsters (Munidopsis sp.) and gastropods (Provanna sp. and Iheyaspira sp.)) between the <span class="hlt">vent</span> fields, they are much more abundant at one <span class="hlt">site</span> than the other. In this study we have examined the bulk carbon, nitrogen and sulfur isotope composition of microbes and fauna at each <span class="hlt">vent</span> field. With these data we have deduced the trophic structure of the communities and the influence of <span class="hlt">vent</span> fluid chemistry. From stable isotope data and end-member <span class="hlt">vent</span> fluid chemistry, we infer that the basis of the trophic structure at Piccard is dominated by sulfur, iron, and hydrogen-oxidizing microbial communities. In comparison, the basis of the Von Damm trophic structure is dominated by microbial communities of sulfur and hydrogen oxidizers, sulfate reducers and methanotrophs. This microbial diversity at the base of the trophic structure is a result of chemical variations in <span class="hlt">vent</span> fluids and processes in the sub-surface that alter the <span class="hlt">vent</span> fluid chemistry. These differences influence higher trophic levels and can be used to explain some of the variability as well as similarity in fauna at the <span class="hlt">vent</span> <span class="hlt">sites</span>. Part of this work was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with National Aeronautics and Space Administration (NASA).</p> <div class="credits"> <p class="dwt_author">Bennett, Sarah; Van Dover, Cindy; Coleman, Max</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">117</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1988DSRA...35.1759B"> <span id="translatedtitle">Allozymic variability of Riftia pachyptila populations from the Galapagos Rift and 21$deg;N <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Species endemic to <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> environments face difficult ecological and evolutionary conditions, especially since <span class="hlt">vent</span> <span class="hlt">sites</span> are irregularly distributed in space and ephemeral. Theoretical predictions for an optimal life history for an endemic organism may not be matched by one of the <span class="hlt">vent</span> community's prominent species, the vestimentiferan Riftia pachyptila. Population samples were collected by submersible from <span class="hlt">vent</span> <span class="hlt">sites</span> along the Galapagos Rift and at 21°N along the East Pacific Rise. Allozymes were used to examine the population genetics of R. pachyptila, including the estimation of genetic variability of the species and differentiation of populations at different <span class="hlt">vent</span> <span class="hlt">sites</span>. For the 13 enzyme loci assayed by starch-gel electrophoresis, 31% were polymorphic. Heterozygosity was low: 1.5%. Genetic divergence between samples from the two regions was small but significant: genetic distance, Nei's D, was 0.008 and Wright's measure of variance partitioning, FST = 0.025 ( p < 0.05) after correction for small sample sizes. Genotypic frequencies also provided evidence of the differentiation of populations: there was a deficiency of one class of heterozygotes ( Pgm-1 98/100) in the pooled samples. The slight genetic differentiation may result from low genetic variability, which may prevent the use of allozymes as markers of gene flow. Endemic <span class="hlt">vent</span> species may experience bottlenecks during colonization of new <span class="hlt">vent</span> <span class="hlt">sites</span> and extinction as <span class="hlt">vents</span> become inactive. Low variability is a predictable outcome of repeated bouts of colonization and extinction, during which the effects of random genetic drift may rapidly decrease genetic variability.</p> <div class="credits"> <p class="dwt_author">Bucklin, Ann</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-10-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">118</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/55479939"> <span id="translatedtitle">Pathways of Carbon and Energy Metabolism of the Epibiotic Community Associated with the Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Shrimp Rimicaris exoculata</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">BackgroundThe shrimp Rimicaris exoculata dominates the faunal biomass at many deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> at the Mid-Atlantic Ridge. In its enlarged gill chamber it harbors a specialized epibiotic bacterial community for which a nutritional role has been proposed.Methodology\\/Principal FindingsWe analyzed specimens from the Snake Pit <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field on the Mid-Atlantic Ridge by complementing a 16S rRNA gene survey with</p> <div class="credits"> <p class="dwt_author">Michael Hügler; Jillian M. Petersen; Nicole Dubilier; Johannes F. Imhoff; Stefan M. Sievert; Lennart Randau</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">119</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/14892313"> <span id="translatedtitle">Adaptive visual metamorphosis in a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> crab</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> along the mid-ocean ridges host ephemeral ecosystems of diverse endemic fauna including several crustacean species, some of which undergo planktonic development as larvae up to 1,000m above and 100km away from the <span class="hlt">vents</span>. Little is known about the role of vision in the life history of <span class="hlt">vent</span> fauna. Here we report that planktonic zoea larvae of the <span class="hlt">vent</span></p> <div class="credits"> <p class="dwt_author">Robert N. Jinks; Tara L. Markley; Elizabeth E. Taylor; Gina Perovich; Ana I. Dittel; Charles E. Epifanio; Thomas W. Cronin</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">120</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012DSRI...62...10K"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> community zonation along environmental gradients at the Lau back-arc spreading center</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Lau back-arc spreading center exhibits gradients in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> habitat characteristics from north to south. Biological zonation within a few meters of <span class="hlt">vents</span> has been described as temperature driven. We constructed georeferenced photomosaics of the seafloor out to tens of meters beyond <span class="hlt">vents</span> to describe peripheral zonation and explore correlations between environmental conditions and the biological community. Cluster analysis separated northern <span class="hlt">sites</span> from southern <span class="hlt">sites</span>, corresponding to a break in substrate from basalt in the north to andesite in the south. Northern <span class="hlt">sites</span> were dominated by anemones, and southern by sponges. A previous suggestion that dominants may be dependent on friability of the substrate was not supported; when visually distinguishable, individual species within taxa showed different patterns. Northern <span class="hlt">sites</span> hosted proportionally more suspension feeding species. Sulfide that can support microbial food sources is at higher concentrations at these <span class="hlt">sites</span>, though bathymetry that may enhance bottom currents is less rugged. Northern <span class="hlt">sites</span> had higher diversity that may result from the overall northwards flow, which would generally permit easier dispersal downcurrent, though we observed no difference in dispersal strategies at different <span class="hlt">sites</span>.</p> <div class="credits"> <p class="dwt_author">Kim, Stacy; Hammerstrom, Kamille</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-04-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_5");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" 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showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_8");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">121</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23002089"> <span id="translatedtitle">When did decapods invade <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>? Clues from the Western Pacific and Indian Oceans.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> are typically located in midocean ridges and back-arc basins and are usually generated by the movement of tectonic plates. Life thrives in these environments despite the extreme conditions. In addition to chemoautotrophic bacteria, decapod crustaceans are dominant in many of the <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> discovered to date. Contrary to the hypothesis that these species are remnants of relic fauna, increasing evidence supports the notion that <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> decapods have diversified in more recent times with previous research attributing the origin of alvinocarid shrimps to the Miocene. This study investigated seven representative decapod species from four <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> throughout the Western Pacific and Indian Oceans. A partitioned mix-model phylogenomic analysis of mitochondrial DNA produced a consistent phylogenetic topology of these <span class="hlt">vent</span>-endemic species. Additionally, molecular dating analysis calibrated using multiple fossils suggested that both bythograeid crabs and alvinocarid shrimps originated in the late Mesozoic and early Cenozoic. Although of limited sampling, our estimates support the extinction/repopulation hypothesis, which postulates recent diversification times for most <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> species due to their mass extinction by global deep-water anoxic/dysoxic events during the Late Cretaceous and Early Tertiary. The continental-derived property of the West Pacific province is compatible with the possibility that <span class="hlt">vent</span> decapods diversified from ancestors from shallow-water regions such as cold seeps. Our results move us a step closer toward understanding the evolutionary origin of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> species and their distribution in the Western Pacific-Indian Ocean Region. PMID:23002089</p> <div class="credits"> <p class="dwt_author">Yang, Jin-Shu; Lu, Bo; Chen, Dian-Fu; Yu, Yan-Qin; Yang, Fan; Nagasawa, Hiromichi; Tsuchida, Shinji; Fujiwara, Yoshihiro; Yang, Wei-Jun</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-02-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">122</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFM.T43D2704F"> <span id="translatedtitle">Magnetic Structure of Backarc Spreading Axis with <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span>; the Southern Mariana Trough</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Seafloor <span class="hlt">hydrothermal</span> systems are important in relation to global heat and chemical fluxes as well as habitat of microbial communities. The substantial variation of <span class="hlt">hydrothermal</span> systems in various tectonic settings has important implications for the magnetic structure of oceanic crust. It has been very difficult to detect the geophysical signature of <span class="hlt">hydrothermal</span> systems from sea-surface data because the small scale of <span class="hlt">hydrothermal</span> systems is below the limit of resolution. The advance of near-bottom survey methods using a submersible, deep-tow, ROV and AUV has made possible high-resolution geophysical mapping around <span class="hlt">hydrothermal</span> areas. Near-bottom magnetic surveys can provide direct information on the magnetization of the shallower oceanic crust, implying <span class="hlt">hydrothermal</span> alteration both in active and fossil <span class="hlt">vent</span> <span class="hlt">sites</span>. Near-bottom three component magnetic measurements on submersible Shinkai 6500 were carried out at <span class="hlt">hydrothermal</span> fields in the Southern Mariana Trough, a slow spreading backarc basin. Fourteen dive surveys were conducted during cruises YK11-10 and YK10-11. We investigated the magnetic structure of four <span class="hlt">hydrothermal</span> systems located at on- and off-axis to clarify how the geophysical and geological setting controls the fluid circulation at small scale. Recent researches at slow spreading ridges showed a relationship between crustal magnetic structure and host rock around <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> (e.g. Tivey and Dyment, 2010), but no observation at backarc spreading axis has been reported so far. We carefully corrected the effects of induced and permanent magnetizations of the submersible by applying the method of Isezaki [1986] with dumped least-square method (Honsho et al., 2009). After subtracting the IGRF from the corrected observed data, we obtained geomagnetic vector anomalies in geographical coordinate. For three transects of the axis, we applied three methods; 2D inversion technique (Parker and Huestis, 1972), 2D forward modeling technique (Honsho et al, 2009) and 2D direct inversion technique (Hussenoeder et al., 1995). Transect 1 (T1) and transect 2 (T2) are parallel and very closely located, crossing the neo-volcanic zone near an on-axis <span class="hlt">hydrothermal</span> <span class="hlt">site</span> (Snail <span class="hlt">Site</span>) at different altitude, 2m and 30m. Transect 3 (T3) also crosses a large on-axis volcanic mound on which another <span class="hlt">hydrothermal</span> <span class="hlt">site</span> (Yamanaka <span class="hlt">Site</span>) is located. The equivalent magnetization calculated on T1 and T2 are similar although their resolutions are different. The one along T3 shows high values around the large volcanic mound and an area of low magnetization near a <span class="hlt">hydrothermal</span> field recognized from high-resolution bathymetry (Yoshikawa et al., 2012). A similar reduction of magnetization above <span class="hlt">hydrothermal</span> fields was also reported in basalt-hosted <span class="hlt">sites</span> along the Mid Atlantic Ridge. The detailed bathymetry (2m grid) collected by AUV Urashima in the study area allows us to investigate the effect of three dimensional structure. We estimate magnetization using a new technique based on 3D forward modeling (Szitkar et al, this meeting). A preliminary result shows a similar but more detailed magnetic structure around the Yamanaka <span class="hlt">Site</span> compared to results of the 2D methods.</p> <div class="credits"> <p class="dwt_author">Fujii, M.; Okino, K.; Mochizuki, N.; Honsho, C.; Szitkar, F.; Dyment, J.; Nakamura, K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">123</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/1024290"> <span id="translatedtitle">Microbial community structure of <span class="hlt">hydrothermal</span> deposits from geochemically different <span class="hlt">vent</span> fields along the Mid-Atlantic Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">To evaluate the effects of local fluid geochemistry on microbial communities associated with active <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> deposits, we examined the archaeal and bacterial communities of 12 samples collected from two very different <span class="hlt">vent</span> fields: the basalt-hosted Lucky Strike (37 17'N, 32 16.3'W, depth 1600-1750 m) and the ultramafic-hosted Rainbow (36 13'N, 33 54.1'W, depth 2270-2330 m) <span class="hlt">vent</span> fields along the Mid-Atlantic Ridge (MAR). Using multiplexed barcoded pyrosequencing of the variable region 4 (V4) of the 16S rRNA genes, we show statistically significant differences between the archaeal and bacterial communities associated with the different <span class="hlt">vent</span> fields. Quantitative polymerase chain reaction (qPCR) assays of the functional gene diagnostic for methanogenesis (mcrA), as well as geochemical modelling to predict pore fluid chemistries within the deposits, support the pyrosequencing observations. Collectively, these results show that the less reduced, hydrogen-poor fluids at Lucky Strike limit colonization by strict anaerobes such as methanogens, and allow for hyperthermophilic microaerophiles, like Aeropyrum. In contrast, the hydrogen-rich reducing <span class="hlt">vent</span> fluids at the ultramafic-influenced Rainbow <span class="hlt">vent</span> field support the prevalence of methanogens and other hydrogen-oxidizing thermophiles at this <span class="hlt">site</span>. These results demonstrate that biogeographical patterns of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> microorganisms are shaped in part by large scale geological and geochemical processes.</p> <div class="credits"> <p class="dwt_author">Flores, Gilberto E [Portland State University; Campbell, James H [ORNL; Kirshtein, Julie D [United States Geological Survey, Reston, VA; Meneghin, Jennifer [Portland State University; Podar, Mircea [ORNL; Steinberg, Joshua [Oregon Episcopal School, Portland, OR; Seewald, Jeffrey S [Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA; Tivey, Margaret Kingston [Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA; Voytek, Mary A [United States Geological Survey & National Aeronautics and Space Administration; Reysenbach, Anna-Louise [Portland State University; Yang, Zamin Koo [ORNL</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">124</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1988DSRA...35.1793L"> <span id="translatedtitle">A comparison of bivalve ( Calyptogena magnifica) growth at two deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in the eastern Pacific</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Analyses of specimens of a common deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> bivalve, Calyptogena magnifica, from two <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> in the eastern Pacific, have been utilized to develop a mathematical model of the growth of this species based on accurate measurements of: (1) in situ rates of dissolution of the aragonitic outer granular shell layer; and (2) the thickness of the outer shell layer remaining at any given point in time at various distances from the umbo. The model permits the variances of each independently measured variable to be combined into a final confidence limit on age at a given size, making possible statistical comparisons of the calculated parameters of the von Bertalanffy growth equation. This model, in turn, provides a powerful tool for quantifying temporal and spatial variability in rates of biological processes both within and between deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> communities. Ontogenetic growth curves for C. magnifica specimens at both <span class="hlt">hydrothermal</span> <span class="hlt">sites</span> suggest that growth rates of this species are several orders of magnitude greater than those reported for the one bivalve ( Tindaria callistiformis) analysed to date from a deep-sea, non-<span class="hlt">vent</span> habitat. These data provide additional evidence that biological processes at submarine <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> along the mid-oceanic ridge system proceed at rates that are extremely rapid for a deep-sea environment and are comparable with those from some shallow water temperate environments. Rates of shell dissolution decreased markedly with increasing distance from <span class="hlt">vent</span> fluids. In a 20 cm distance spanning 10 cm into a bivalve assemblage atop an active <span class="hlt">vent</span> at Rose Garden (Galapagos Rift) to 10 cm outside the assemblage, dissolution rates of the outer granular layer of C. magnifica declined 100-fold (from 355.4 to 3.5 ?m y -1, respectively) in in situ exposures of approximately 210 days. At distances ranging from 1 to 6 m away from active <span class="hlt">vent</span> <span class="hlt">sites</span>, no measurable thickness (<1 ?m) of C. magnifica shells had dissolved. The latter dissolution rates are far below estimates reported in the literature for shells of this species exposed in situ at comparable depths in the eastern Pacific and these results have profound implications for estimating 'residence' times of empty shell valves at inactive <span class="hlt">vent</span> <span class="hlt">sites</span>.</p> <div class="credits"> <p class="dwt_author">Lutz, Richard A.; Fritz, Lowell W.; Cerrato, Robert M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-10-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">125</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22964374"> <span id="translatedtitle">Comparison of thiol subproteome of the <span class="hlt">vent</span> mussel Bathymodiolus azoricus from different Mid-Atlantic Ridge <span class="hlt">vent</span> <span class="hlt">sites</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Deep-sea <span class="hlt">hydrothermal</span> mussels Bathymodiolus azoricus live in the mixing zone where <span class="hlt">hydrothermal</span> fluid mixes with bottom seawater, creating large gradients in the environmental conditions and are one of the most studied <span class="hlt">hydrothermal</span> species as a model of adaptation to extreme conditions. Thiol proteins, i.e. proteins containing a thiol or sulfhydryl group (SH) play major roles in intracellular stress defense against reactive oxygen species (ROS) and are especially susceptible to oxidation. However, they are not particularly abundant, representing a small percentage of proteins in the total proteome and therefore are difficult to study by proteomic approaches. Activated thiol sepharose (ATS) was used for the rapid and quantitative selection of proteins comprising thiol- or disulfide-containing subproteomes. This study aims to isolate thiol-containing proteins from the gills of B. azoricus collected in distinct <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and to study the thiol-containing subproteome as a function of <span class="hlt">site</span>-specific susceptibility to ROS. Results show that ATS is a powerful tool to isolate the thiol-containing sub-proteome and differently-expressed protein spots showed significant differences among the three <span class="hlt">vent</span> <span class="hlt">sites</span>, supporting previous findings that specific environmental conditions are crucial for ROS formation and that B. azoricus have different susceptibilities to oxidative stress depending on the <span class="hlt">vent</span> <span class="hlt">site</span> they inhabit. PMID:22964374</p> <div class="credits"> <p class="dwt_author">Company, Rui; Torreblanca, Amparo; Cajaraville, Miren; Bebianno, Maria João; Sheehan, David</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-10-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">126</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010GeoJI.180..883V"> <span id="translatedtitle">Application of acoustic noise and self-potential localization techniques to a buried <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> (Waimangu Old Geyser <span class="hlt">site</span>, New Zealand)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A seismo-acoustic and self-potential survey has been performed in the <span class="hlt">hydrothermal</span> area of the old Waimangu Geyser (New Zealand), which was violently erupting a century ago. Nowadays, no surface activity is visible there. We set-up an array of 16 geophones and recorded a high and steady acoustic ambient noise. We applied the matched field processing (MFP) approach to the acoustic data to locate the sources responsible for the ambient noise. The white noise constraint processor reveals the presence of a unique and well-focused acoustic source at a depth of 1.5 m below the seismic array. For this very shallow source, the application of MFP enabled the determination of both the source location and the dispersion curve of seismic velocity. The study was completed by self-potential (SP) measurements on several profiles around the acoustic noise source, which displayed a large positive anomaly above it. The results of the SP inversion gave an electric streaming current density source very close to the acoustic one. Both sources likely belong to a shallow <span class="hlt">hydrothermal</span> structure interpreted as a small convective cell of boiling water beneath an impermeable layer. The joint application of these methods is a promising technique to recognize <span class="hlt">hydrothermal</span> structures and to study their dynamics.</p> <div class="credits"> <p class="dwt_author">Vandemeulebrouck, J.; Roux, P.; Gouédard, P.; Legaz, A.; Revil, A.; Hurst, A. W.; Bolève, A.; Jardani, A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-02-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">127</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23231657"> <span id="translatedtitle">Comparison of intact polar lipid with microbial community composition of <span class="hlt">vent</span> deposits of the Rainbow and Lucky Strike <span class="hlt">hydrothermal</span> fields.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The intact polar lipid (IPL) composition of twelve <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> deposits from the Rainbow (RHF) and Lucky Strike <span class="hlt">hydrothermal</span> fields (LSHF) has been investigated in order to assess its utility as a proxy for microbial community composition associated with deep-sea <span class="hlt">hydrothermal</span> locations. Gene-based culture-independent surveys of the microbial populations of the same <span class="hlt">vent</span> deposits have shown that microbial populations are different in the two locations and appear to be controlled by the geochemical and geological processes that drive <span class="hlt">hydrothermal</span> circulation. Large differences in the IPL composition between these two <span class="hlt">sites</span> are evident. In the ultramafic-hosted RHF, mainly archaeal-IPLs were identified, including those known to be produced by hyperthermophilic Euryarchaeota. More specifically, polyglycosyl derivatives of archaeol and macrocyclic archaeol indicate the presence of hyperthermophilic methanogenic archaea in the <span class="hlt">vent</span> deposits, which are related to members of the Methanocaldococcaceae or Methanococcaceae. In contrast, bacterial IPLs dominate IPL distributions from LSHF, suggesting that bacteria are more predominant at LSHF than at RHF. Bacterial Diacyl glycerol (DAG) IPLs containing phosphocholine, phosphoethanolamine or phosphoglycerol head groups were identified at both <span class="hlt">vent</span> fields. In some <span class="hlt">vent</span> deposits from LSHF ornithine lipids and IPLs containing phosphoaminopentanetetrol head groups were also observed. By comparison with previously characterized bacterial communities at the <span class="hlt">sites</span>, it is likely the DAG-IPLs observed derive from Epsilon- and Gammaproteobacteria. Variation in the relative amounts of archaeal versus bacterial IPLs appears to indicate differences in the microbial community between <span class="hlt">vent</span> <span class="hlt">sites</span>. Overall, IPL distributions appear to be consistent with gene-based surveys. PMID:23231657</p> <div class="credits"> <p class="dwt_author">Gibson, R A; van der Meer, M T J; Hopmans, E C; Reysenbach, A-L; Schouten, S; Sinninghe Damsté, J S</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">128</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004AGUFM.V43F..06C"> <span id="translatedtitle">The Geologic Setting of <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> at Mariana Arc Submarine Volcanoes: High-Resolution Bathymetry and ROV Observations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Remotely operated vehicle (ROV) dives were made at 7 submarine volcanoes between 14-23° N in the Mariana Arc in April 2004 with the ROPOS ROV. Six of these volcanoes were known to be <span class="hlt">hydrothermally</span> active from CTD data collected during a previous expedition in March 2003: NW Rota-1, E Diamante, NW Eifuku, Daikoku, Kasuga-2, and Maug, a partly submerged caldera. The physical setting of <span class="hlt">hydrothermal</span> <span class="hlt">venting</span> varies widely from volcano to volcano. High-resolution bathymetric surveys of the summits of NW Rota-1 and NW Eifuku volcanoes were conducted with an Imagenex scanning sonar mounted on ROPOS. Near bottom observations during ROPOS dives were recorded with digital video and a digital still camera and the dives were navigated acoustically from the R/V Thompson using an ultra-short baseline system. The mapping and dive observations reveal the following: (1) The summits of some volcanoes have pervasive diffuse <span class="hlt">venting</span> (NW Rota-1, Daikoku, NW Eifuku) suggesting that <span class="hlt">hydrothermal</span> fluids are able to circulate freely within a permeable edifice. At other volcanoes, the <span class="hlt">hydrothermal</span> <span class="hlt">venting</span> is more localized (Kasuga-2, Maug, E Diamante), suggesting more restricted permeability pathways. (2) Some volcanoes have both focused <span class="hlt">venting</span> at depth and diffuse <span class="hlt">venting</span> near the summit (E Diamante, NW Eifuku). Where the <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> are focused, fluid flow appears to be localized by massive lava outcrops that form steep cliffs and ridges, or by subsurface structures such as dikes. High-temperature (240° C) <span class="hlt">venting</span> was only observed at E Diamante volcano, where the "Black Forest" <span class="hlt">vent</span> field is located on the side of a constructional cone near the middle of E Diamante caldera at a depth of 350 m. On the side of an adjacent shallower cone, the <span class="hlt">venting</span> style changed to diffuse discharge and it extended all the way up into the photic zone (167 m). At NW Eifuku, the pattern of both deep-focused and shallow-diffuse <span class="hlt">venting</span> is repeated. "Champagne <span class="hlt">vent</span>" is located at 1607 m, ~150 m below the summit, and is characterized by focused flow of CO2-rich fluids, whereas the summit has extensive areas of diffuse <span class="hlt">venting</span> and is covered with thick bacterial mats. (3) Some of the most remarkable <span class="hlt">vent</span> <span class="hlt">sites</span> are deep, narrow volcanic craters at NW Rota-1 and Daikoku volcanoes. The crater at NW Rota-1 volcano (named "Brimstone Pit") is 15-m wide, 20-m deep, funnel shaped, and was actively erupting ash, lapilli, and molten sulfur. The rim of Brimstone Pit is composed of welded spatter and is located at 550 m depth, about 30 m below the summit. Other diffuse <span class="hlt">hydrothermal</span> <span class="hlt">sites</span> at NW Rota-1 are located along the rocky summit ridge. At Daikoku volcano, an extraordinary crater emitting cloudy <span class="hlt">hydrothermal</span> fluid was found at 375 m depth on the north shoulder of the volcano, about 75 m below the summit. This crater was at least 135 m deep and had a remarkably cylindrical cross-section with a diameter of ~50 m. ROPOS descended 75 m into the crater and was still at least 60 m above the bottom, according to the altimeter, when we were forced to cease operations due to weather. In addition, diffuse <span class="hlt">hydrothermal</span> fluids seep from large areas of the summit and upper slopes of Daikoku.</p> <div class="credits"> <p class="dwt_author">Chadwick, W. W.; Embley, R. W.; de Ronde, C. E.; Stern, R. J.; Hein, J.; Merle, S.; Ristau, S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">129</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17684750"> <span id="translatedtitle">Shell nacre ultrastructure and depressurisation dissolution in the deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">This study describes the micro-morphological features of the shell nacre in the <span class="hlt">vent</span> mytilid Bathymodiolus azoricus collected along a bathymetric gradient of deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> of the mid-Atlantic ridge (MAR). Pressure-dependent crystallisation patterns were detected in animals subjected to post-capture hydrostatic simulations. We provide evidence for the following: (1) shell micro morphology in B. azoricus is similar to that of several <span class="hlt">vent</span> and cold-seep species, but the prismatic shell layers may vary among bathymodiolids; (2) nacre micro-morphology of mussels from three <span class="hlt">vent</span> <span class="hlt">sites</span> of the MAR did not differ significantly; minor differences do not appear to be related to hydrostatic pressure, but rather to calcium ion availability; (3) decompression stress may cause drop off in pH of the pallial fluid that damages nascent crystals, and in a more advanced phase, the aragonite tablets as well as the continuous layer of mature nacre; and (4) adverse effects of decompression on calcium salt deposition in shells was diminished by re-pressurisation of specimens. The implications of the putative influence of hydrostatic pressure on biomineralisation processes in molluscs are discussed. PMID:17684750</p> <div class="credits"> <p class="dwt_author">Kadar, Eniko; Checa, Antonio G; Damasceno-Oliveira, Alfredo; Oliveira, Alfredo N D P; Machado, Jorge P</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">130</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003AGUFM.B12C0802G"> <span id="translatedtitle">Formation and Stabilization of Mixed Valence Ferrihydrite on Bacterial Surfaces From <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The dynamics of iron oxidation and reduction at <span class="hlt">hydrothermal</span> <span class="hlt">sites</span> is an important biogeochemical process which involves major biomineralization of iron oxides. In this study, we have studied biomineralization by the Rimicaris exoculata shrimp collected at a Mid Atlantic Ridge <span class="hlt">hydrothermal</span> <span class="hlt">vent</span>. The structure, morphology and impurities distributions of the minerals were analyzed by Transmission electron microscopy and electron energy loss spectroscopy. The main minerals observed are clusters of two-lines ferrihydrite, found attached to the bacterial cells present in the organ scaphognatite of the shrimp. EELS measurements at the Fe 2p excitation demonstrate that the ferrihydrite is bearing a mixed valence iron distribution. The stability of this uncommon phase is then discussed based on work previously reported in literature for analogous poorly ordered iron oxides. The specific biomineralization mechanism might be a key to the stabilization of this phase.</p> <div class="credits"> <p class="dwt_author">Gloter, A.; Zbinden, M.; Guyot, F.; Gaill, F.; Colliex, C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">131</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ntis.gov/search/product.aspx?ABBR=ADA436043"> <span id="translatedtitle">Shallow Water <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Survey in Azores With Cooperating ASV and AUV.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ntis.gov/search/index.aspx">National Technical Information Service (NTIS)</a></p> <p class="result-summary">This project report covers the following objectives: (1) Demonstrate two vehicle communication. (2) Obtain Video confirmation of Shallow Water <span class="hlt">Hydro-thermal</span> <span class="hlt">Vent</span> Activity using Video with location obtained from an independent source.</p> <div class="credits"> <p class="dwt_author">A. J. Healey A. M. Pascoal R. Santos C. Silvestre P. Oliveira</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">132</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/61433834"> <span id="translatedtitle">Mercury concentrations in invertebrates from Mid-Atlantic Ridge <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Mercury determinations were carried out in mussels (Bathymodiolus\\u000a azoricus) from three Mid-Atlantic Ridge <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> (Lucky\\u000a Strike, Menez Gwen and Rainbow) and shrimps (Rimicaris exoculata and\\u000a Mirocaris fortunata) from Rainbow. Among the three <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>,\\u000a mussels of Menez Gwen show the highest levels of total Hg and comparing\\u000a mussels and shrimps from Rainbow the former show more Hg than shrimps.</p> <div class="credits"> <p class="dwt_author">I Martins; V Costa; F Porteiro; A Cravo; RS Santos</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">133</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://aem.asm.org/content/68/12/6392.full.pdf"> <span id="translatedtitle">Bacterial Group II Introns in a Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Environment</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://nsdl.org/nsdl_dds/services/ddsws1-1/service_explorer.jsp">NSDL National Science Digital Library</a></p> <p class="result-summary">This Applied and Environmental Microbiology journal article (PDF) reports the discovery of group II introns in a bacterial mat sample collected from a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> near 9°N on the East Pacific Rise. One of the introns was shown to self-splice in vitro. This is the first example of marine bacterial introns from molecular population structure studies of microorganisms that live in the proximity of <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate">2010-03-10</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">134</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFM.B43G0496O"> <span id="translatedtitle">Microbial Primary Productivity in <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Chimneys at Middle Valley, Juan de Fuca Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Chemosynthetic primary productivity supports <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystems, but the extent of that productivity has not been well measured. To examine the role that environmental temperature plays in controlling carbon fixation rates, and to assess the degree to which microbial community composition, in situ geochemistry, and mineralogy influence carbon fixation, we conducted a series of shipboard incubations across a range of temperatures (4, 25, 50 and 90°C) and at environmentally relevant geochemical conditions using material recovered from three <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> chimneys in the Middle Valley <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field (Juan de Fuca Ridge). Net rates of carbon fixation (CFX) were greatest at lower temperatures, and were similar among structures. Rates did not correlate with the mineralogy or the geochemical composition of the high temperature fluids at each chimney. No obvious patterns of association were observed between carbon fixation rates and microbial community composition. Abundance of selected functional genes related to different carbon fixation pathway exhibited striking differences among the three study <span class="hlt">sites</span>, but did not correlate with rates. Natural carbon isotope ratios implicate the Calvin Benson Bassham Cycle as the dominant mechanism of primary production in these systems, despite the abundance of genes related to other pathways (and presumably some degree of activity). Together these data reveal that primary productivity by endolithic communities does not exhibit much variation among these chimneys, and further reveal that microbial activity cannot easily be related to mineralogical and geochemical assessments that are made at a coarser scale. Indeed, the relationships between carbon fixation rates and community composition/functional gene abundance were also likely obfuscated by differences in scale at which these measurements were made. Regardless, these data reveal the degree to which endolithic, anaerobic carbon fixation contributes to regional primary production, and via modeling reveal the role that this process plays in deep-sea and global carbon cycling.</p> <div class="credits"> <p class="dwt_author">Olins, H. C.; Rogers, D.; Frank, K. L.; Girguis, P. R.; Vidoudez, C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">135</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/8924410"> <span id="translatedtitle">The morphology of the dorsal eye of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp, Rimicaris exoculata.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The bresiliid shrimp, Rimicaris exoculata, lives in large masses on the sides of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> chimneys at two <span class="hlt">sites</span> on the Mid-Atlantic Ridge. Although essentially no daylight penetrates to depths of 3500 m, very dim light is emitted from the <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> themselves. To exploit this light, R. exoculata has evolved a modified compound eye on its dorsal surface that occupies about 0.5% of the animal's body volume. The eye's morphology suggests that it is extremely sensitive to light. The cornea of the dorsal eye is smooth with no dioptric apparatus. The retina consists of two wing-shaped lobes that are fused across the midline anteriorly. The rhabdomeral segments of the 7000 ommatidia form a compact layer of photosensitive membrane with an entrance aperture of more than 26 mm2. Within this layer, the volume density of rhabdom is more than 70%. Below the rhabdomeral segments, a thick layer of white diffusing cells scatters light upward into the photoreceptors. The arhabdomeral segments of the five to seven photoreceptors of each ommatidium are mere strands of cytoplasm that expand to accommodate the photoreceptor nuclei. The rhabdom is comprised of well-organized arrays of microvilli, each with a cytoskeletal core. The rhabdomeral segment cytoplasm contains mitochondria, but little else. The perikaryon contains a band of mitochondria, but has only small amounts of endoplasmic reticulum. There is no ultrastructural indication of photosensitive membrane cycling in these photoreceptors. Vestigial screening pigment cells and screening pigment granules within the photoreceptors are both restricted to the inner surface of the layer of the white diffusing cells. Below the retina, photoreceptor axons converge in a fanshaped array to enter the dorsal surface of the brain. The eye's size and structure are consistent with a role for vision in shrimp living at abyssal <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. PMID:8924410</p> <div class="credits"> <p class="dwt_author">O'Neill, P J; Jinks, R N; Herzog, E D; Battelle, B A; Kass, L; Renninger, G H; Chamberlain, S C</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">136</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/k5981862m6743835.pdf"> <span id="translatedtitle">Extensive gene flow among mytilid ( Bathymodiolus thermophilus ) populations from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> of the eastern Pacific</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Prior studies of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus thermophilus (Bivalvia: Mytilidae), provided conflicting predictions about the dispersal ability and population structure of this highly specialized species. Analyses of morphological features associated with its larval shells revealed a feeding larval stage that might facilitate dispersal between ephemeral <span class="hlt">vent</span> habitats. In contrast, an allozyme study revealed substantial genetic differentiation between samples taken</p> <div class="credits"> <p class="dwt_author">C. Craddock; W. R. Hoeh; R. A. Lutz; R. C. Vrijenhoek</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">137</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.mbari.org/staff/vrijen/PDFS/Goffredi_2004AEM.pdf"> <span id="translatedtitle">Novel Forms of Structural Integration between Microbes and a <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Gastropod from the Indian Ocean</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Here we describe novel forms of structural integration between endo- and episymbiotic microbes and an unusual new species of snail from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in the Indian Ocean. The snail houses a dense population of -proteobacteria within the cells of its greatly enlarged esophageal gland. This tissue setting differs from that of all other <span class="hlt">vent</span> mollusks, which harbor sulfur-oxidizing endosymbionts in</p> <div class="credits"> <p class="dwt_author">Shana K. Goffredi; Anders Waren; Victoria J. Orphan; Cindy L. Van Dover; Robert C. Vrijenhoek</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">138</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/34807428"> <span id="translatedtitle">Bacterial and archaeal populations at two shallow <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> off Panarea Island (Eolian Islands, Italy)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The aim of this study was to investigate the microbial community thriving at two shallow <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> off Panarea Island\\u000a (Italy). Physico-chemical characteristics of thermal waters were examined in order to establish the effect of the <span class="hlt">vents</span> on\\u000a biodiversity of both Bacteria and Archaea. Water and adjacent sediment samples were collected at different times from two\\u000a <span class="hlt">vents</span>, characterised by different</p> <div class="credits"> <p class="dwt_author">Teresa Luciana Maugeri; Valeria Lentini; Concetta Gugliandolo; Francesco Italiano; Sylvie Cousin; Erko Stackebrandt</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">139</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24430487"> <span id="translatedtitle">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> Epsilonproteobacteria encode a conserved and widespread nitrate reduction pathway (Nap).</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Despite the frequent isolation of nitrate-respiring Epsilonproteobacteria from deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, the genes coding for the nitrate reduction pathway in these organisms have not been investigated in depth. In this study we have shown that the gene cluster coding for the periplasmic nitrate reductase complex (nap) is highly conserved in chemolithoautotrophic, nitrate-reducing Epsilonproteobacteria from deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. Furthermore, we have shown that the napA gene is expressed in pure cultures of <span class="hlt">vent</span> Epsilonproteobacteria and it is highly conserved in microbial communities collected from deep-sea <span class="hlt">vents</span> characterized by different temperature and redox regimes. The diversity of nitrate-reducing Epsilonproteobacteria was found to be higher in moderate temperature, diffuse flow <span class="hlt">vents</span> than in high temperature black smokers or in low temperatures, substrate-associated communities. As NapA has a high affinity for nitrate compared with the membrane-bound enzyme, its occurrence in <span class="hlt">vent</span> Epsilonproteobacteria may represent an adaptation of these organisms to the low nitrate concentrations typically found in <span class="hlt">vent</span> fluids. Taken together, our findings indicate that nitrate reduction is widespread in <span class="hlt">vent</span> Epsilonproteobacteria and provide insight on alternative energy metabolism in <span class="hlt">vent</span> microorganisms. The occurrence of the nap cluster in <span class="hlt">vent</span>, commensal and pathogenic Epsilonproteobacteria suggests that the ability of these bacteria to respire nitrate is important in habitats as different as the deep-sea <span class="hlt">vents</span> and the human body. PMID:24430487</p> <div class="credits"> <p class="dwt_author">Vetriani, Costantino; Voordeckers, James W; Crespo-Medina, Melitza; O'Brien, Charles E; Giovannelli, Donato; Lutz, Richard A</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">140</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2001AGUFM.V32A0959O"> <span id="translatedtitle">Study of <span class="hlt">Hydrothermal</span> Particulate Matter from a Shallow <span class="hlt">Venting</span> System, offshore Nayarit, Mexico</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A shallow (30 ft) <span class="hlt">hydrothermal</span> <span class="hlt">site</span> named ``Cora'' (after the indigenous people thereby) was surveyed and sampled throughout direct observation with SCUBA diving during November 25 to December 4, 2000. A total of 10 dives were conducted in order to obtain representative samples from an 85oC fluid source of approximately 10 cm in diameter. Inherent difficulties to the sampling, such as poor visibility and strong bottom currents were overcome and samples of <span class="hlt">hydrothermal</span> fluid, gas, rocks, and particulate matter were collected directly from the <span class="hlt">vent</span>. Water samples and <span class="hlt">hydrothermal</span> fluid were taken with a homemade 1 l cylindrical bottles of two lines by flushing in from the bottom for about ten minutes until total displacement of the seawater; similar procedure was carried out for gas samples. Particulate matter was collected with 0.4mm polycarbonate membrane filters and preserved in a desiccators at a fridge temperature until analysis onshore. Preliminary description of the rock samples suggest that pyritization is the main mineralisation process. Filters containing <span class="hlt">hydrothermal</span> particulate matter were surveyed under the scanning electron microscope in order to identify the nature (inorganic and organic), as well as the chemistry of the particles. SEM examination revealed the presence of particles of different kind that suggests high degree of mixing and re-suspension: Planctonic organisms and organic matter appeared to be abundant; 25 micron particles of different carbonate faces and inorganic particles of silicates were also recognized. Distinctive euhedral colloidal grains were identified as the resulting process of precipitation from the solution. Microanalysis of iron and sulfur content of 10 micron particles indicate a very likely sulphide mineral face (greigite); 8 micron cinnabar particles are consistent with the mineralization conditions, observed as well in the inner walls of the <span class="hlt">vent</span>. Analyses of dissolved and particulate trace metals are still ongoing at labs in New Zealand and Mexico and will be incorporated in a near future.</p> <div class="credits"> <p class="dwt_author">Ortega-Osorio, A.; Prol-Ledesma, R. M.; Reyes, A. G.; Rubio-Ramos, M. A.; Torres-Vera, M. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-12-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_6");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">141</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17813375"> <span id="translatedtitle">Carbon-13 depletion in a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel: suggestion of a chemosynthetic food source.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Tissues of a mytilid mussel from the Clambake I <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> in the Galápagos Rift zone are strikingly depleted in carbon-13 relative to the tissues of other marine organisms. The stable carbon isotope composition of this mussel suggests that chemoautotrophic bacteria present in the <span class="hlt">hydrothermal</span> waters are a major food source for filter-feeding organisms in this abyssal environment. PMID:17813375</p> <div class="credits"> <p class="dwt_author">Rau, G H; Hedges, J I</p> <p class="dwt_publisher"></p> <p class="publishDate">1979-02-16</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">142</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/53617739"> <span id="translatedtitle">Geomicrobiology of <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> in Yellowstone Lake: Phylogenetic and Functional Analysis suggest Importance of Geochemistry (Invited)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Yellowstone Lake (Yellowstone National Park, WY, USA) is a large, high-altitude, fresh-water lake that straddles the most recent Yellowstone caldera, and is situated on top of significant <span class="hlt">hydrothermal</span> activity. An interdisciplinary study is underway to evaluate the geochemical and geomicrobiological characteristics of several <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> environments sampled using a remotely operated vehicle, and to determine the degree to which these</p> <div class="credits"> <p class="dwt_author">W. P. Inskeep; R. Macur; Z. Jay; S. Clingenpeel; A. Tenney; D. Lavalvo; W. C. Shanks; T. McDermott; J. Kan; Y. Gorby; L. A. Morgan; S. Yooseph; J. Varley; K. Nealson</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">143</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1988DSRA...35..985W"> <span id="translatedtitle">Deep-water zooplankton of the Guaymas basin <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Zooplankton from the Guaymas Basin deep-sea <span class="hlt">vent</span> field were collected with a 1 m 2 MOCNESS to examine the distribution of total standing stock, taxonomic composition, size-frequency distribution of zooplankton, and the species composition of calanoid copepods. Low altitude (˜ 100 m above the bottom) horizontal tows along and across the axis of the basin's southern trough, and oblique tows from the bottom of the basin (˜ 2000 m) to the surface were made. Total biomass in near-bottom samples (range: 13-46 cc/1000 m 3) was only about a factor of 10 lower than in the upper 100 m. However, there was little or no evidence for enrichment of biomass in the ˜ 100 m zone above the <span class="hlt">vent</span> <span class="hlt">site</span> relative to biomass at the same depth horizon over non-<span class="hlt">vent</span> areas. Total numbers of individuals ranged between 2600 and 4800/1000 m 3. Calanoid copepods consistently ranked first in abundance of counts of the taxa, followed by cyclopoid copepods, ostracods, chaetognaths, and amphipods. Other less abundant taxa, but in some cases important contributors to total biomass, were coelenterates (siphonophores, medusae), decapod shrimp, and polychaetes. Size-frequency analysis of individuals from each taxon indicated that the biomass and abundance spectra do not fit the theoretically expected spectra based on weight-dependent metabolism and growth. The pyramid of biomass was substantially different from the pyramid of numbers in this deep-sea community. Of the 67 species of copepods identified in two samples taken on low altitude tows, only 15 co-occurred in both samples. Many of the species in this relatively diverse community remain to be described. Larval and post-larval forms of benthic clams, gastropods, polychaetes, and crustaceans associated with the <span class="hlt">vents</span> were collected 100-200 m above the southern trough, indicating the post-larvae may play an active role in dispersal of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> species.</p> <div class="credits"> <p class="dwt_author">Wiebe, Peter H.; Copley, Nancy; Van Dover, Cindy; Tamse, Armando; Manrique, Fernando</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">144</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/10390825"> <span id="translatedtitle">Genetic and morphometric characterization of mussels (Bivalvia: Mytilidae) from mid-atlantic <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Mussels were collected from deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> along the Mid-Atlantic Ridge. Specimens from the Snake Pit <span class="hlt">site</span> were previously identified genetically and anatomically as Bathymodiolus puteoserpentis, but the relationships of mussels from other <span class="hlt">sites</span> (Logatchev and Lucky Strike) were unclear. Molecular genetic and morphological techniques were used to assess differences among these mussel populations. The results indicate that the range for B. puteoserpentis extends from Snake Pit to Logatchev, and that an unnamed second species, B. n. sp., occurs at Lucky Strike. Analysis of mitochondrial NADH dehydrogenase subunit 4 (ND4) revealed 13% sequence divergence between the two species. Nei's genetic distance (D) based on 14 allozyme loci was 0.112. A multivariate morphometric analysis yielded a canonical discriminant function that correctly identified individuals from these <span class="hlt">sites</span> to species 95% of the time. PMID:10390825</p> <div class="credits"> <p class="dwt_author">Maas, P A; O'Mullan, G D; Lutz, R A; Vrijenhoek, R C</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">145</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1690812"> <span id="translatedtitle">Life in the extreme environment at a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span>: haemoglobin in a deep-sea copepod.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">This is the first study, to my knowledge, quantifying the respiratory pigment haemoglobin discovered in a deep-sea copepod. Haemoglobin in copepods has previously been documented in only one other species from the deep water of an Italian lake. Specimens of the siphonostomatoid Scotoecetes introrsus Humes were collected during submersible dives at 2500 m depth near a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> at the East Pacific Rise (9 degrees N). The haemoglobin content in the copepods' haemolymph was 4.3 +/- 0.6 micrograms per individual female (n = 6) and 1.8 +/- 0.1 micrograms per individual male (n = 6). Weight-specific concentrations of haemoglobin were identical for females and males (0.25 +/- 0.04 and 0.26 +/- 0.02 microgram per microgram dry weight, respectively). These haemoglobin concentrations are higher than those found in other small crustaceans. Activity of the electron transport system indicated that the respiration rates in S. introrsus (13.7 +/- 7.7 microliters O2 per milligram dry weight per hour) were similar to those in the shallow-water copepod Acartia tonsa (9.1 +/- 1.3 microliters O2 per milligram dry weight per hour). It was concluded that the possession of highly concentrated haemoglobin allows S. introrsus to colonize a geologically young, thermally active <span class="hlt">site</span> such as the vicinity of a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span>, despite the prevailing oxygen depletion.</p> <div class="credits"> <p class="dwt_author">Sell, A F</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">146</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3187469"> <span id="translatedtitle">Complete Genome Sequence of Thermococcus sp. Strain 4557, a Hyperthermophilic Archaeon Isolated from a Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Area</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Thermococcus sp. strain 4557 is a hyperthermophilic anaerobic archaeon isolated from the deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> Guaymas Basin <span class="hlt">site</span> in the Gulf of California at a depth of 2,000 m. Here, we present the complete genome sequence of Thermococcus sp. 4557, which consists of a single circular chromosome of 2,011,320 bp with a G+C content of 56.08%.</p> <div class="credits"> <p class="dwt_author">Wang, Xingna; Gao, Zhaoming; Xu, Xun; Ruan, Lingwei</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">147</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/42550633"> <span id="translatedtitle">Four-Hundred-and-Ninety-Million-Year Record of Bacteriogenic Iron Oxide Precipitation at Sea-Floor <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Fe oxide deposits are commonly found at <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> at mid-ocean ridge and back-arc sea floor spreading centers, seamounts associated with these spreading centers, and intra-plate seamounts, and can cover extensive areas of the seafloor. These deposits can be attributed to several abiogenic processes and commonly contain micron-scale filamentous textures. Some filaments are cylindrical casts of Fe oxyhydroxides formed</p> <div class="credits"> <p class="dwt_author">Crispin T. S. Little; Sarah E. J. Glynn; Rachel A. Mills</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">148</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17255002"> <span id="translatedtitle">On the origin of biochemistry at an alkaline <span class="hlt">hydrothermal</span> <span class="hlt">vent</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">A model for the origin of biochemistry at an alkaline <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> has been developed that focuses on the acetyl-CoA (Wood-Ljungdahl) pathway of CO2 fixation and central intermediary metabolism leading to the synthesis of the constituents of purines and pyrimidines. The idea that acetogenesis and methanogenesis were the ancestral forms of energy metabolism among the first free-living eubacteria and archaebacteria, respectively, stands in the foreground. The synthesis of formyl pterins, which are essential intermediates of the Wood-Ljungdahl pathway and purine biosynthesis, is found to confront early metabolic systems with steep bioenergetic demands that would appear to link some, but not all, steps of CO2 reduction to geochemical processes in or on the Earth's crust. Inorganically catalysed prebiotic analogues of the core biochemical reactions involved in pterin-dependent methyl synthesis of the modern acetyl-CoA pathway are considered. The following compounds appear as probable candidates for central involvement in prebiotic chemistry: metal sulphides, formate, carbon monoxide, methyl sulphide, acetate, formyl phosphate, carboxy phosphate, carbamate, carbamoyl phosphate, acetyl thioesters, acetyl phosphate, possibly carbonyl sulphide and eventually pterins. Carbon might have entered early metabolism via reactions hardly different from those in the modern Wood-Ljungdahl pathway, the pyruvate synthase reaction and the incomplete reverse citric acid cycle. The key energy-rich intermediates were perhaps acetyl thioesters, with acetyl phosphate possibly serving as the universal metabolic energy currency prior to the origin of genes. Nitrogen might have entered metabolism as geochemical NH3 via two routes: the synthesis of carbamoyl phosphate and reductive transaminations of alpha-keto acids. Together with intermediates of methyl synthesis, these two routes of nitrogen assimilation would directly supply all intermediates of modern purine and pyrimidine biosynthesis. Thermodynamic considerations related to formyl pterin synthesis suggest that the ability to harness a naturally pre-existing proton gradient at the <span class="hlt">vent</span>-ocean interface via an ATPase is older than the ability to generate a proton gradient with chemistry that is specified by genes. PMID:17255002</p> <div class="credits"> <p class="dwt_author">Martin, William; Russell, Michael J</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-10-29</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">149</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013GGG....14.3352T"> <span id="translatedtitle">Cemented mounds and <span class="hlt">hydrothermal</span> sediments on the detachment surface at Kane Megamullion: A new manifestation of <span class="hlt">hydrothermal</span> <span class="hlt">venting</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Long-lived detachment faults are now known to be important in tectonic evolution of slow-spreading mid-ocean ridges, and there is increasing evidence that fluid flow plays a critical role in development of detachment systems. Here we document a new manifestation of low-temperature <span class="hlt">hydrothermal</span> <span class="hlt">venting</span> associated with the detachment fault that formed Kane Megamullion ˜3.3-2.1 m.y. ago in the western rift-valley wall of the Mid-Atlantic Ridge. <span class="hlt">Hydrothermal</span> effects on the detachment surface include (1) cemented mounds of igneous rock and chalk debris containing <span class="hlt">hydrothermal</span> Mn oxides and Fe oxyhydroxides, and (2) layered deposits of similar Fe-Mn minerals ± interbedded chalks. Mounds are roughly conical, ˜1-10 m high, and contain primarily basalts with lesser gabbro, serpentinite, and polymict breccia. The layered Fe-Mn-rich sediments are flat-bedded to contorted and locally are buckled into low-relief linear or polygonal ridges. We propose that the mounds formed where <span class="hlt">hydrothermal</span> fluids discharged through the detachment hanging wall near the active fault trace. <span class="hlt">Hydrothermal</span> precipitates cemented hanging-wall debris and welded it to the footwall, and this debris persisted as mounds as the footwall was exhumed and surrounding unconsolidated material sloughed off the sloping detachment surface. Some of the layered Fe-Mn-rich deposits may have precipitated from fluids discharging from the hanging-wall <span class="hlt">vents</span>, but they also precipitated from low-temperature fluids <span class="hlt">venting</span> from the exposed footwall through overlying chalks. Observed natural disturbance and abnormally thin hydrogenous Fe-Mn crusts on some contorted, <span class="hlt">hydrothermal</span> Fe-Mn-rich chalks on ˜2.7 Ma crust suggest diffuse <span class="hlt">venting</span> that is geologically recent. Results of this study imply that there are significant fluid pathways through all parts of detachment systems and that low-temperature <span class="hlt">venting</span> through fractured detachment footwalls may continue for several million years off-axis.</p> <div class="credits"> <p class="dwt_author">Tucholke, Brian E.; Humphris, Susan E.; Dick, Henry J. B.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">150</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1987DSRA...34..379B"> <span id="translatedtitle">Benthopelagic macrozooplankton communities at and near deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in the eastern Pacific ocean and the Gulf of California</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Benthopelagic zooplankton communities at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> on the East Pacific Rise and in Guaymas Basin are enriched in terms of both biomass and abundance with respect to non-<span class="hlt">vent</span> areas, but depleted relative to biomass of surface zooplankton communities. Larval and juvenile stages of many benthic species, including Calyptogena spp., Bathymodiolus thermophilus, Nuculana sp., two undescribed species of limpets, Dahlella caldariensis, Bythograea sp., Munidopsis sp., epicaridean isopods, and lysianassid amphipods, were collected in the water column 1-5 m above <span class="hlt">vent</span> areas. Since much of the zooplankton community is derived from the benthic community, macrozooplankton abundance and composition differ among <span class="hlt">vent</span> <span class="hlt">sites</span> in accordance with the nature and extent of development of the benthic community and depend, ultimately, on the history of <span class="hlt">hydrothermal</span> activity at each <span class="hlt">site</span>.</p> <div class="credits"> <p class="dwt_author">Berg, Carl J.; Van Dover, Cindy Lee</p> <p class="dwt_publisher"></p> <p class="publishDate">1987-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">151</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.nsf.gov/news/overviews/earth-environ/interactive.jsp"> <span id="translatedtitle">Sea <span class="hlt">Vent</span> Viewer</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://nsdl.org/nsdl_dds/services/ddsws1-1/service_explorer.jsp">NSDL National Science Digital Library</a></p> <p class="result-summary">This web <span class="hlt">site</span> serves as an educational overview of National Science Foundation (NSF) earth and environmental science research focusing on <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> systems. It features an interactive viewer which allows users to explore <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> systems with the touch of a mouse. Dragging the cursor around the screen moves the field of view while clicking on numbered items reveals informational pages about each inhabitant.</p> <div class="credits"> <p class="dwt_author">Foundation, National S.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">152</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2006JSR....56...37K"> <span id="translatedtitle">First report on the micro-essential metal concentrations in bivalve shells from deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> bivalve Bathymodiolus azoricus is naturally exposed to elevated levels of trace elements (Fe, Cu and Zn) and is therefore a suitable model organism to study physiological adaptations to extreme environments. Whole shells and various shell compartments of B. azoricus from two geochemically different <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> of the Mid- Atlantic Ridge were analysed regarding their micro-essential metal concentration, and compared with levels in their shore analogues from contaminated <span class="hlt">sites</span> reported in the relevant literature. Concentrations of Cu and Zn in <span class="hlt">hydrothermal</span> shells exceeded many-fold levels reported for polluted areas worldwide, and thus reveal a prominent potential of this organ to accumulate bivalent metals (average concentrations of metals in whole shells of mussels from the Lucky Strike <span class="hlt">vent</span> <span class="hlt">site</span> were above average 280 ?g g - 1 for Fe, 80 ?g g - 1 for Cu and 40 ?g g - 1 for Zn). Moreover, shell metal concentrations reflected fluid composition. In spite of higher metal concentrations in the periostracum than in the nacre, the latter has a higher metal burden because of its greater mass as compared to the thin periostracum. Additionally, metals were shown to bind reversibly to the outer surface of the shell (up to 6% of both total Cu and Zn, and 30% of total Fe from shells were recovered in an acidic solution in which the shells were soaked for 12 hours). It is concluded that shells are good indicators of environmental levels of Fe, Cu and Zn at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and thus may be considered markers of putative changes in metal exposure over the mussel's lifespan.</p> <div class="credits"> <p class="dwt_author">Kádár, Enikõ; Costa, Valentina</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">153</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1988DSRA...35.1681H"> <span id="translatedtitle">Temporal change in megafauna at the Rose Garden <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> (Galapagos Rift; eastern tropical Pacific)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> communities must undergo substantial temporal change because of their dynamic physical milieu. This was verified in March 1985, when the Rose Garden <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> on the Galapagos Rift was revisited after 5 1/4 years' absence. Comparison of photographs from the two visits revealed considerable faunal change. Among the hosts to chemoautotrophic bacteria, vestimentiferans were reduced from dominance to very low numbers. The mytilid was now extremely abundant and dominated <span class="hlt">vent</span> openings. Vesicomyids also were more abundant. In general, <span class="hlt">vent</span>-field suspension feeders had declined; anemones were distinctly less abundant, and siphonophores and enteropneusts were virtually absent. The decline of serpulids was likely, but less obvious. Of the mobile scavengers and carnivores, both galatheids and whelks were distincly more common. These community changes appear to result from both continuing recruitment and changes in the physical milieu. While the growth of some populations could have resulted from expanding opportunities, the population of at least one, the vesicomyid, had not achieved carrying capacity in 1979, and this could have pertained to others as well. The decrease of vestimentiferans may have been caused by declining <span class="hlt">vent</span>-water flux, a process that would favor mytilids, or more complete <span class="hlt">vent</span>-water filtration by the mytilids themselves. The same factors also could explain the reduction of <span class="hlt">vent</span>-field filter feeders. These observations suggest that early stages in the cycle of Galapagos-type <span class="hlt">vent</span> communities are likely to be dominated by vestimentiferans, but that bivalves will replace them with time.</p> <div class="credits"> <p class="dwt_author">Hessler, Robert R.; Smithey, William M.; Boudrias, Michel A.; Keller, Clifford H.; Lutz, Richard A.; Childress, James J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-10-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">154</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/19483771"> <span id="translatedtitle">Survey of genome size in 28 <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> species covering 10 families.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Knowledge of genome size is a useful and necessary prerequisite for the development of many genomic resources. To better understand the origins and effects of DNA gains and losses among species, it is important to collect data from a broad taxonomic base, but also from particular ecosystems. Oceanic thermal <span class="hlt">vents</span> are an interesting model to investigate genome size in very unstable environments. Here we provide data estimated by flow cytometry for 28 <span class="hlt">vent</span>-living species among the most representative from different <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. We also report the genome size of closely related coastal decapods. Haploid C-values were compared with those previously reported for species from corresponding orders or infraorders. This is the first broad survey of 2C values in <span class="hlt">vent</span> organisms. Contrary to expectations, it shows that certain <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> species have particularly large genomes. The <span class="hlt">vent</span> squat lobster Munidopsis recta has the largest genome yet reported for any anomuran: 2C=31.1 pg=30.4x10(9) bp. In several groups, such as Brachyura, Phyllodocida, and Veneroida, <span class="hlt">vent</span> species have genomes that clearly rank at the high end of published values for each group. We also describe the highest DNA content yet recorded for the Brachyura (coastal crabs Xantho pilipes and Necora puber). Finally, analysis of genome size variation across populations revealed unexpected intraspecific variation in the <span class="hlt">vent</span> shrimp Mirocaris fortunata that could not be attributed simply to ploidy changes. PMID:19483771</p> <div class="credits"> <p class="dwt_author">Bonnivard, Eric; Catrice, Olivier; Ravaux, Juliette; Brown, Spencer C; Higuet, Dominique</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">155</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUFM.B12B..04H"> <span id="translatedtitle">Microbial anaerobic methane cycling in the subseafloor at the Von Damm <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field, Mid-Cayman Rise</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Mid-Cayman Rise (MCR) is Earth's deepest and slowest spreading mid-ocean ridge located in the western Caribbean. With an axial rift valley floor at a depth of ~4200-6500 m, it represents one of the deepest sections of ridge crest worldwide. In 2009, the world's deepest <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> (Piccard at 4960 m) and an ultramafic-influenced system only 20 km away on top of an oceanic core complex (Von Damm at 2350 m) were discovered along the MCR. Each <span class="hlt">site</span> is hosted in a distinct geologic setting with different thermal and chemical regimes. The Von Damm <span class="hlt">site</span> is a particularly interesting location to examine chemolithoautotrophic subseafloor microbial communities due to the abundant hydrogen, methane, and organic compounds in the <span class="hlt">venting</span> fluids. Here, we used a combination of stable isotope tracing, next-generation sequencing, and single cell techniques to determine the identity, activity, and genomic repertoire of subseafloor anaerobic archaea involved in methane cycling in <span class="hlt">hydrothermal</span> fluids <span class="hlt">venting</span> at the Von Damm <span class="hlt">site</span>. Molecular sequencing of phylogenetic marker genes revealed the presence of diverse archaea that both generate and consume methane across a geochemical and thermal spectrum of <span class="hlt">vents</span>. Stable isotope tracing experiments were used to detect biological utilization of formate and dissolved inorganic carbon, and methane generation at 70 °C under anaerobic conditions. Results indicate that methanogenesis with formate as a substrate is occurring at 70 °C at two Von Damm <span class="hlt">sites</span>, Ginger Castle and the Main Orifice. The results are consistent with thermodynamic predictions for carbon speciation at the temperatures encountered at the ultramafic-hosted Von Damm, where formate is predicted to be thermodynamically stable, and may thus serve as a an important source of carbon. Diverse thermophilic methanogenic archaea belonging to the genera Methanothermococcus were detected at all <span class="hlt">vent</span> <span class="hlt">sites</span> with both 16S rRNA tag sequencing and single cell sorting. Other methanogenic archaea are also present, including the hyperthermophile Methanopyrus, as well as methanogens that can use acetate, methanol, and other simple carbon compounds for methane generation, such as the genera Methanosaeta and Methermicoccus. In addition, uncultivated lineages related to putative anaerobic methane cycling archaea were detected in the fluids. These include the GOM Arc I clade within the Methanosarcinales, a group previously described from Gulf of Mexico methane seeps and thought to be methanogenic, as well as the ANME-1 and ANME-2 lineages, which are likely anaerobically oxidizing methane. On-going metagenomic sequencing of both mixed microbial communities and single cells from <span class="hlt">venting</span> fluids will reveal the genomic repertoire, evolutionary relationships, and adaptations of these unique methane-cycling anaerobic archaea in the subseafloor at the Von Damm <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field.</p> <div class="credits"> <p class="dwt_author">Huber, J. A.; Reveillaud, J. C.; Stepanauskas, R.; McDermott, J. M.; Sylva, S. P.; Seewald, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">156</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40557469"> <span id="translatedtitle">In situ microsensor studies of a shallow water <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> at Milos, Greece</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The microenvironment and microcirculation of a shallow water <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> system was studied together with the benthic primary production at Milos, Greece. In situ microprofiles of O2, pH, H2S and temperature were obtained using a miniaturised version of a profiling instrument. The sediment temperature increased toward the centre of the <span class="hlt">vent</span> system, reaching a surface maximum of 100°C in the</p> <div class="credits"> <p class="dwt_author">Frank Wenzhöfer; Ola Holby; Ronnie N Glud; Helle K Nielsen; Jens K Gundersen</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">157</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40119835"> <span id="translatedtitle">Shell nacre ultrastructure and depressurisation dissolution in the deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">This study describes the micro-morphological features of the shell nacre in the <span class="hlt">vent</span> mytilid Bathymodiolus azoricus collected along a bathymetric gradient of deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> of the mid-Atlantic ridge (MAR). Pressure-dependent\\u000a crystallisation patterns were detected in animals subjected to post-capture hydrostatic simulations. We provide evidence for\\u000a the following: (1) shell micro morphology in B. azoricus is similar to that of</p> <div class="credits"> <p class="dwt_author">Eniko Kadar; Antonio G. Checa; Alfredo N. D. P. Oliveira; Jorge P. Machado</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">158</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/m4606t1kt8314548.pdf"> <span id="translatedtitle">A new bathymodioline mussel symbiosis at the Juan de Fuca <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Until recently, the only major <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> biogeographic province not known to include bathymodioline mussels was the spreading centers of the northeast Pacific, but deep-sea dives using DSV Alvin on the Endeavor segment of the Juan de Fuca Ridge (47°56N 129°06W; ?2,200 m depth) in August 1999 yielded the only recorded bathymodioline mytilids from these northeastern Pacific <span class="hlt">vents</span>. One specimen in</p> <div class="credits"> <p class="dwt_author">Z. P. McKiness; E. R. McMullin; C. R. Fisher; C. M. Cavanaugh</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">159</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41133086"> <span id="translatedtitle">Extensive deep-sea dispersal of postlarval shrimp from a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> fields on the Mid-Atlantic Ridge (MAR) are small (no more than 0.1–1.0 km2) and widely spaced (a reported average of one field per 175km between 11°N and 40°N). Their faunas are similar and usually dominated by shrimp of the family Bresiliidae. Little is known about the way these animals (and other members of the <span class="hlt">vent</span> fauna) disperse and</p> <div class="credits"> <p class="dwt_author">P. J. Herring; D. R. Dixon</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">160</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.terrapub.co.jp/journals/JO/pdf/5706/57060663.pdf"> <span id="translatedtitle">Submersible Observations of the <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Communities on the Iheya Ridge, Mid Okinawa Trough, Japan</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">During the Dives Nos. 409, 410, 480 and 481 of the Japanese submersible Shinkai 2000, conducted on June 10 and 11, 1989 and on May 16 and 17, 1990, several <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and prosperous <span class="hlt">vent</span> associated\\u000a biological communities were found on the northern slope of the Iheya Ridge in the Mid-Okinawa Trough (27°32.5? N, 126°58.5?\\u000a E: depth 1,400 m). The</p> <div class="credits"> <p class="dwt_author">Suguru Ohta; Dongsung Kim</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_7");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return 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src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">161</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40985661"> <span id="translatedtitle">First report on the micro-essential metal concentrations in bivalve shells from deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> bivalve Bathymodiolus azoricus is naturally exposed to elevated levels of trace elements (Fe, Cu and Zn) and is therefore a suitable model organism to study physiological adaptations to extreme environments. Whole shells and various shell compartments of B. azoricus from two geochemically different <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> of the Mid- Atlantic Ridge were analysed regarding their micro-essential metal concentration,</p> <div class="credits"> <p class="dwt_author">Enikõ Kádár; Valentina Costa</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">162</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003AGUFMGP31B0754L"> <span id="translatedtitle">Rock Magnetic Investigation of Felsic <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> System: Results from ODP Leg 193 to Eastern Manus Basin, Papua New Guinea</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In November-December, 2000, an active <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field in the Eastern Manus back-arc basin, Papua New Guinea, known as the PACMANUS <span class="hlt">vent</span> field, was drilled during ODP Leg 193. This <span class="hlt">vent</span> field has been considered as a modern-day analog of massive volcanogenic sulfide deposits within felsic volcanic sequence. The recovery was generally low due to fragility of rocks. Detailed paleomagnetic and rock magnetic analyses were performed on rock samples recovered from three major <span class="hlt">sites</span> (<span class="hlt">Sites</span> 1188, 1189 and 1191). <span class="hlt">Site</span> 1188, a low-temperature diffused <span class="hlt">venting</span> region, was drilled to 370 mbsf utilizing a combination of RCB, Hammer Drill, ADCB and casing, and <span class="hlt">Site</span> 1189, a black smoker region, was drilled to a depth of 200 mbsf using RCB. Paleomagnetic analysis shows that recovered rock samples have inclination close to the present-day Earth field. The top 35 m of PACMANUS <span class="hlt">vent</span> field consists of fresh to moderately altered dacite-rhyodacite and exhibits moderately high natural remanent magnetization (< 6 A/m). Although there are small intervals of markedly less intensive alteration, the region below this extrusive layer is largely comprised of pervasively altered rocks with little evidence of sulfide deposit and exhibits as a whole a low magnetization intensity. However, two intervals with high remanent magnetization (> 6 A/m) were recognized below the upper extrusive layer at <span class="hlt">Site</span> 1188 (135-211 mbsf and 280-370 mbsf) and one interval at <span class="hlt">Site</span> 1189 (137-190 mbsf). In particular, the samples between 135-211-mbsf interval at <span class="hlt">Site</span> 1188 have extremely high remanence with intensities ranging up to 300-500 A/m. Although pockets of magnetite are not uncommon in the ancient <span class="hlt">hydrothermal</span> ore bodies, they have seldom been documented in modern-day system, and little is known about the physical and chemical condition that allows the magnetite to form in <span class="hlt">hydrothermal</span> systems. Two possibilities of magnetite formation and its apparent alignment with the Earth field are explored: one that these magnetites precipitated from magnetite-rich fluid as it cooled from above the Curie temperature (TRM) and the other that magnetization was acquired by the growth of magnetite grains below the Curie temperature (CRM). Understanding the origin and behavior of these magnetic mineral assemblages may in turn provide a valuable constraint on the physical and chemical conditions of subseafloor <span class="hlt">hydrothermal</span> systems, which are very poorly known at the moment.</p> <div class="credits"> <p class="dwt_author">Lee, S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">163</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010GeoRL..3718303Z"> <span id="translatedtitle">A reduced crustal magnetization zone near the first observed active <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field on the Southwest Indian Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Inversion of near-bottom magnetic data reveals a well-defined low crustal magnetization zone (LMZ) near a local topographic high (37°47?S, 49°39?E) on the ultraslow-spreading Southwest Indian Ridge (SWIR). The magnetic data were collected by the autonomous underwater vehicle ABE on board R/V DaYangYiHao in February-March 2007. The first active <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field observed on the SWIR is located in Area A within and adjacent to the LMZ at the local topographic high, implying that this LMZ may be the result of <span class="hlt">hydrothermal</span> alteration of magnetic minerals. The maximum reduction in crustal magnetization is 3 A/M. The spatial extent of the LMZ is estimated to be at least 6.7 × 104 m2, which is larger than that of the LMZs at the TAG <span class="hlt">vent</span> field on the Mid-Atlantic Ridge (MAR), as well as the Relict Field, Bastille, Dante-Grotto, and New Field <span class="hlt">vent-sites</span> on the Juan de Fuca Ridge (JdF). The calculated magnetic moment, i.e., the product of the spatial extent and amplitude of crustal magnetization reduction is at least -3 × 107 Am2 for the LMZ on the SWIR, while that for the TAG field on the MAR is -8 × 107 Am2 and that for the four individual <span class="hlt">vent</span> fields on the JdF range from -5 × 107 to -3 × 107 Am2. Together these results indicate that crustal demagnetization is a common feature of basalt-hosted <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields at mid-ocean ridges of all spreading rates. Furthermore, the crustal demagnetization of the Area A on the ultraslow-spreading SWIR is comparable in strength to that of the TAG area on the slow-spreading MAR.</p> <div class="credits"> <p class="dwt_author">Zhu, Jian; Lin, Jian; Chen, Yongshun J.; Tao, Chunhui; German, Christopher R.; Yoerger, Dana R.; Tivey, Maurice A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">164</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1986Sci...231.1139J"> <span id="translatedtitle">In Situ Measurements of Chemical Distributions in a Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Large changes in the concentration of sulfide around a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> in the Galapagos Rift provide direct evidence for the consumption of sulfide by the organisms of the <span class="hlt">vent</span> community. These changes were detected with a new chemical analyzer capable of measuring silicate, sulfide, oxygen, and temperature on the sea floor at depths of 2500 meters. More than 10,000 measurements showed systematic variations in the sulfide and oxygen concentrations due to biogenic oxidation of sulfide in the <span class="hlt">hydrothermal</span> solutions. Silicate concentration was highly correlated with temperature, but different trends were observed at different locations.</p> <div class="credits"> <p class="dwt_author">Johnson, Kenneth S.; Beehler, Carl L.; Sakamoto-Arnold, Carole M.; Childress, James J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">165</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17818544"> <span id="translatedtitle">In situ measurements of chemical distributions in a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Large changes in the concentration of sulfide around a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> in the Galápagos Rift provide direct evidence for the consumption of sulfide by the organisms of the <span class="hlt">vent</span> community. These changes were detected with a new chemical analyzer capable of measuring silicate, sulfide, oxygen, and temperature on the sea floor at depths of 2500 meters. More than 10,000 measurements showed systematic variations in the sulfide and oxygen concentrations due to biogenic oxidation of sulfide in the <span class="hlt">hydrothermal</span> solutions. Silicate concentration was highly correlated with temperature, but different trends were observed at different locations. PMID:17818544</p> <div class="credits"> <p class="dwt_author">Johnson, K S; Beehler, C L; Sakamoto-Arnold, C M; Childress, J J</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">166</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=40849"> <span id="translatedtitle">Intracellular coexistence of methano- and thioautotrophic bacteria in a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The coexistence of two phylogenetically distinct symbiont species within a single cell, a condition not previously known in any metazoan, is demonstrated in the gills of a Mid-Atlantic Ridge <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel (family Mytilidae). Large and small symbiont morphotypes within the gill bacteriocytes are shown to be separate bacterial species by molecular phylogenetic analysis and fluorescent in situ hybridization. The two symbiont species are affiliated with thioautotrophic and methanotrophic symbionts previously found in monospecific associations with closely related mytilids from deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and hydrocarbon seeps. Images Fig. 1 Fig. 3</p> <div class="credits"> <p class="dwt_author">Distel, D L; Lee, H K; Cavanaugh, C M</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">167</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002AGUFM.V72A1288D"> <span id="translatedtitle">A Retrievable Mineral Microcosm for Examining Microbial Colonization and Mineral Precipitation at Seafloor <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Although seafloor <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> environments are known to support thriving ecosystems, the microscale physical and chemical environment suitable for microbial colonization and the identity of pioneering organisms is unknown. Because of the fragility of young chimneys and their ephemeral nature, novel methods for sample retrieval and analysis are required. The mineral microcosm consists of four titanium mesh chambers containing crushed minerals mounted on a titanium base that allows for fluid flow through the chambers. The chambers can be filled with different minerals or mineral mixtures (or no minerals) to supply different substrates for microbial colonization and different local microenvironments as minerals react with the surrounding fluids. The device sets on top of an active <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> for a period of days to weeks to allow colonization and mineral reaction. The mineral microcosm was deployed during the Atlantis/Alvin Extreme 2001 Cruise (Oct.- Nov.,2001) to 9° 50'N on the East Pacific Rise a total of three times, for ~ 24, ~ 96, and ~ 48 hours each. It was deployed in two different environments, twice in lower temperature (<300°C), diffuse-flow environments and once (for ~96 hours) in a higher temperature black smoker environment (>350°C).Seed minerals included sulfides, sulfates, magnetite, apatite, and quartz, both individually and in mixtures. In the first 24-hour deployment, dissolution of anhydrite but not sulfide minerals within the chambers indicated high temperatures in chamber interiors and rapid reaction rates. Temperatures measured on chamber exteriors before retrieval ranged from 4° -98°C. The 96-hour deployment on a hot <span class="hlt">vent</span> (fluid ~370°C before deployment) resulted in extensive mineral precipitation and chimney growth inside the mineral chambers, on the outer surfaces of the chambers, and on the platform as a whole, creating micro-chimneys several centimeters tall. The young chimneys were mainly composed of pyrite with lesser amounts of chalcopyrite and sphalerite and with thin veneers of anhydrite on exterior surfaces in contact with seawater. Bulk trace element analyses of the newly formed chimneys show concentrations of Ag, Cd, Co, Cr, Mo, Ni, and Pb (up to ~200 ppm) but a lack of As, Sn, U, and W. On the last deployment in a polychaete-rich, diffuse-flow area (<span class="hlt">vent</span> temperature ~300°C), the microcosm was covered with biofilm and polychaete tubes had formed on the surface during the ~48 hours on the <span class="hlt">vent</span>. Temperatures at chamber exteriors had decreased to 16- 20°C, suggesting that the <span class="hlt">vent</span> was not vigorous enough to maintain a large flow through the chambers. Although no evidence for microbial colonization was obtained in these initial deployments, the device can simulate the mineralogy and temperature gradients of a natural <span class="hlt">hydrothermal</span> chimney. Young chimney samples of known age (~96 hours) obtained from the second deployment were analyzed by synchrotron X-ray computed tomography for porosity and mineralogy and compared with existing chimneys at these <span class="hlt">sites</span> (see companion abstract by Ashbridge, et al.).</p> <div class="credits"> <p class="dwt_author">Dunn, E. E.; Holloway, J. R.; Cary, S.; Voglesonger, K. M.; Ashbridge, D. A.; O'Day, P. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">168</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008JGRB..113.8S06S"> <span id="translatedtitle">Culture-independent characterization of a novel microbial community at a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> at Brothers volcano, Kermadec arc, New Zealand</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The bacterial and archaeal diversity of a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> microbial community at Brothers volcano situated in the Kermadec arc, ˜400 km off the north coast of New Zealand, was examined using culture-independent molecular analysis. An unusual microbial community was detected with only 1% and 40% of the bacterial phylotypes exhibiting >92% small subunit (SSU) rRNA gene sequence similarity with cultivated and noncultivated microbes, respectively. Of the 29 bacterial representative phylotypes, over one third of the SSU rRNA gene sequences retrieved belonged to uncultivated candidate divisions including OP1, OP3, OP5, OP8, OD1, and OP11. All archaeal phylotypes belonged to the phylum Euryarchaeota in the uncultivated groups deep <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> euryarchaeotal (DHVE) I and II or to the phylum Korarchaeota. Like the bacterial clone library, only a small proportion of archaeal SSU rRNA gene sequences (˜2% and 20%) displayed >92% sequence identity with any archaeal isolates or noncultivated microbes, respectively. Although the bacterial phylotypes detected were phylogenetically most similar to microbial communities detected in methane, hydrocarbon, and carbon dioxide-based <span class="hlt">hydrothermal</span> and seep environments, no phylotypes directly associated with anaerobic methane oxidation and mcrA activity could be detected. The geochemical composition of the <span class="hlt">vent</span> fluids at the Brothers-lower cone sample <span class="hlt">site</span> is unusual and we suggest that it may play a prominent role in the species selection of this microbial community.</p> <div class="credits"> <p class="dwt_author">Stott, M. B.; Saito, J. A.; Crowe, M. A.; Dunfield, P. F.; Hou, S.; Nakasone, E.; Daughney, C. J.; Smirnova, A. V.; Mountain, B. W.; Takai, K.; Alam, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-08-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">169</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/14676368"> <span id="translatedtitle">Organics in chimneys and water samples from deep-sea <span class="hlt">hydrothermal</span> systems: implications for sub-<span class="hlt">vent</span> biosphere.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Searching for life in extreme terrestrial environments can be a model of that for extraterrestrial life. Submarine <span class="hlt">hydrothermal</span> system is one of promising <span class="hlt">sites</span> for the frontier of life on the earth. Here seawater and <span class="hlt">vent</span> chimnies were collected from deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> at Suiyo Seamount, Izu-bonin arc, Pacific Ocean as a part of Archaean Park Project. Pure seawater sample of 300 degrees C (purity>97%) could be collected. Dissolved and total hydrolyzable amino acids were determined by ion-exchange HPLC, and their enantiomeric ratio was measured by reversed-phase HPLC for the first time. Glycine and serine were two most abundant amino acids, followed by other proteinous amino acids such as alanine, glutamic acid and aspartic acid. Non-proteinous amino acids were detected as minor constituents. Most of the amino acids detected were of the L-form. Thus amino acids of abiotic origin were quite minor, and most of the amino acids detected were formed biologically. These results, together with analytical results of the <span class="hlt">vent</span> chimney samples, suggest that there is active microbial activities near the <span class="hlt">hydrothermal</span> systems. PMID:14676368</p> <div class="credits"> <p class="dwt_author">Horiuchi, Tsukasa; Kobayashi, Kensei; Takano, Yoshinori; Marumo, Katsumi; Nakashima, Miwako; Yamagishi, Akihiko; Ishibashi, Jun-ichiro; Urabe, Tetsuro</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-10-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">170</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011NatGe...4..367Y"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> as a kinetically stable source of iron-sulphide-bearing nanoparticles to the ocean</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> emit sulphur and metals to the ocean. Particular attention has been paid to <span class="hlt">hydrothermal</span> fluxes of iron, a limiting micronutrient of marine primary production. <span class="hlt">Vent</span>-derived iron was previously thought to rapidly oxidize and precipitate around <span class="hlt">vents</span>. However, organic matter can bind to and stabilize dissolved and particulate iron in <span class="hlt">hydrothermal</span> plumes, facilitating its dispersion into the open ocean. Here, we report measurements of the chemical speciation of sulphide and iron in high-temperature fluids emanating from <span class="hlt">vents</span> in the East Pacific Rise and the Eastern Lau Spreading Center. We show that pyrite nanoparticles--composed of iron and sulphur--account for up to 10% of the filterable iron (less than 200nm in size) in these fluids. We suggest that these particles form before the discharge of the <span class="hlt">vent</span> fluid. We estimate that pyrite nanoparticles sink more slowly than larger plume particles, and are more resistant to oxidation than dissolved Fe(II) and FeS. We suggest that the discharge of iron in the form of pyrite nanoparticles increases the probability that <span class="hlt">vent</span>-derived iron will be transported over long distances in the deep ocean.</p> <div class="credits"> <p class="dwt_author">Yücel, Mustafa; Gartman, Amy; Chan, Clara S.; Luther, George W.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">171</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://aem.asm.org/cgi/reprint/68/9/4613.pdf"> <span id="translatedtitle">Isolation of Tellurite and Selenite-Resistant Bacteria from <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> of the Juan de Fuca Ridge in the Pacific Ocean</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Deep-ocean <span class="hlt">hydrothermal-vent</span> environments are rich in heavy metals and metalloids and present excellent <span class="hlt">sites</span> for the isolation of metal-resistant microorganisms. Both metalloid-oxide-resistant and metalloid-oxide- reducing bacteria were found. Tellurite- and selenite-reducing strains were isolated in high numbers from ocean water near <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, bacterial films, and sulfide-rich rocks. Growth of these isolates in media containing K2TeO3 or Na2SeO3 resulted in</p> <div class="credits"> <p class="dwt_author">Christopher Rathgeber; Natalia Yurkova; Erko Stackebrandt; J. Thomas Beatty; Vladimir Yurkov</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">172</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=183184"> <span id="translatedtitle">Evidence for Methylotrophic Symbionts in a <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Mussel (Bivalvia: Mytilidae) from the Mid-Atlantic Ridge †</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Symbioses between chemolithoautotrophic bacteria and the major macrofaunal species found at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> have been reported for numerous <span class="hlt">sites</span> in the Pacific Ocean. We present microscopical and enzymatic evidence that methylotrophic bacteria occur as intracellular symbionts in a new species of mytilid mussel discovered at the Mid-Atlantic Ridge <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. Two distinct ultrastructural types of gram-negative procaryotic symbionts were observed within gill epithelial cells by transmission electron microscopy: small coccoid or rod-shaped cells and larger coccoid cells with stacked intracytoplasmic membranes typical of methane-utilizing bacteria. Methanol dehydrogenase, an enzyme diagnostic of methylotrophs, was detected in the mytilid gills, while tests for ribulose-1,5-bisphosphate carboxylase, the enzyme diagnostic of autotrophy via the Calvin cycle, were negative. Stable carbon isotope values (?13C) of mytilid tissue (?32.7 and ?32.5% for gill and foot tissues, respectively) fall within the range of values reported for Pacific <span class="hlt">vent</span> symbioses but do not preclude the use of <span class="hlt">vent</span>-derived methane reported to be isotopically heavy relative to biogenically produced methane. Images</p> <div class="credits"> <p class="dwt_author">Cavanaugh, Colleen M.; Wirsen, Carl O.; Jannasch, H. W.</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">173</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008AGUFM.B51D0416V"> <span id="translatedtitle">Evidence for a Chemoautotrophically Based Food Web at Inactive <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> (Manus Basin)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> are ephemeral systems. When <span class="hlt">venting</span> shuts down, sulfide-dependent taxa die off, and non-<span class="hlt">vent</span> taxa can colonize the hard substrata. In Manus Basin (Papua New Guinea), where active and inactive sulfide mounds are interspersed, hydroids, cladorhizid sponges, barnacles, and bamboo sponges, and other invertebrate types may occupy inactive sulfide mounds. Carbon and nitrogen isotopic compositions of animals occupying inactive sulfide mounds are consistent with nutritional dependence on either chemoautotrophically or photosynthetically produced organic material, but sulfur isotopic compositions of these animals point to a chemoautotrophic source of sulfur from dissolved sulfide in <span class="hlt">vent</span> fluids rather than sulfur derived from seawater sulfate through photosynthesis. Given that suspension-feeding and micro- carnivorous invertebrates are the biomass dominants at inactive sulfide mounds, the primary source of chemoautotrophic nutrition is likely suspended particulates and organisms delivered from nearby active <span class="hlt">vents</span>.</p> <div class="credits"> <p class="dwt_author">van Dover, C. L.; Erickson, K.; Macko, S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">174</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.fasebj.org/cgi/reprint/7/6/558.pdf"> <span id="translatedtitle">Aspects of life development at deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Hydrothennal <span class="hlt">vent</span> organisms are living in an unexpected deep-sea environment, several thousand meters below the surface, where the earth's crustal plates are spreading apart. The <span class="hlt">vent</span> fluids are usually hot (350#{176}C), anoxic, and contain high concentrations of hydrogen sulfide. This environment may be considered as extreme given the pressure, the high temperature, the chemical toxicity of the fluids, and the</p> <div class="credits"> <p class="dwt_author">SB GAUL</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">175</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUFM.B13C0512M"> <span id="translatedtitle">High-pressure hydrogen respiration in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> samples from the deep biosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Cultivation of organisms from the deep biosphere has met with many challenges, chief among them the ability to replicate this extreme environment in a laboratory setting. The maintenance of in situ pressure levels, carbon sources, and gas concentrations are important, intertwined factors which may all affect the growth of subsurface microorganisms. Hydrogen in particular is of great importance in <span class="hlt">hydrothermal</span> systems, but in situ hydrogen concentrations are largely disregarded in attempts to culture from these <span class="hlt">sites</span>. Using modified Hungate-type culture tubes (Bowles et al. 2011) within pressure-retaining vessels, which allow for the dissolution of higher concentrations of gas than is possible with other culturing methods, we have incubated <span class="hlt">hydrothermal</span> chimney and <span class="hlt">hydrothermally</span>-altered rock samples from the Lost City and Mid-Cayman Rise <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields. Hydrogen concentrations up to 15 mmol/kg have been reported from Lost City (Kelley et al. 2005), but data are not yet available from the recently-discovered Mid-Cayman <span class="hlt">site</span>, and the elevated concentration of 30 mmol/kg is being used in all incubations. We are using a variety of media types to enrich for various metabolic pathways including iron and sulfur reduction under anoxic or microaerophilic conditions. Incubations are being carried out at atmospheric (0.1 MPa), in situ (9, 23, or 50 MPa, depending on <span class="hlt">site</span>), and elevated (50 MPa) pressure levels. Microbial cell concentrations, taxonomic diversity, and metabolic activities are being monitored during the course of these experiments. These experiments will provide insight into the relationships between microbial activities, pressure, and gas concentrations typical of deep biosphere environments. Results will inform further culturing studies from both fresh and archived samples. References cited: Bowles, M.W., Samarkin, V.A., Joye, S.B. 2011. Improved measurement of microbial activity in deep-sea sediments at in situ pressure and methane concentration. Limnology and Oceanography Methods 9:499-506 Kelley, D.S., Karson, J.A., Früh-Green, G.L., Yoerger, D.R., Shank, T.M., et al. 2005. A Serpentinite-Hosted Ecosystem: The Lost City <span class="hlt">Hydrothermal</span> Field. Science 307:1428-1434</p> <div class="credits"> <p class="dwt_author">Morgan-Smith, D.; Schrenk, M. O.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">176</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004GMS...144..213P"> <span id="translatedtitle">Significance of polysaccharides in microbial physiology and the ecology of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> environments</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Hyperthermophilic microorganisms (those with maximum growth temperatures of 90°C and above) are known to inhabit deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> environments and are suspected of being present in the associated subsurface biosphere. One characteristic of the growth physiology of many heterotrophic hyperthermophiles is the capacity to use complex polysaccharides (e.g., ?- and ?-linked glucans as well as non-glucan hemicellulases) as carbon and energy sources. Polysaccharides may also play an important ecological role in the deep-sea subsurface biosphere as the structural elements of biofilms harboring both heterotrophic and chemolithotrophic microorganisms, representing a range of growth temperatures. Genome sequence analysis of several hyperthermophiles indicates that the enzymatic machinery to synthesize and hydrolyze polysaccharides is present in this group of microorganisms. This is supported by the biochemical characteristics of glycosidases from hyperthermophiles in addition to the observation that several hyperthermophiles form biofilms in pure and co-culture. It remains to be seen if biofilms form the basis for a subsurface biosphere but this possibility seems likely given the physiological characteristics of several hyperthermophiles and mesophiles, representative of microorganisms previously isolated from <span class="hlt">vent</span> <span class="hlt">sites</span>.</p> <div class="credits"> <p class="dwt_author">Pysz, Marybeth A.; Montero, Clemente I.; Chhabra, Swapnil R.; Kelly, Robert M.; Rinker, Kristina D.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">177</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17316784"> <span id="translatedtitle">Heat shock protein expression pattern (HSP70) in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">We previously reported evidence of increased levels of DNA damage in the <span class="hlt">hydrothermal</span> mussel Bathymodiolus azoricus, which suggested that the species was not fully resistant to the natural toxicity of its deep-sea <span class="hlt">vent</span> environment. In the present study, HSP70 was used as a biomarker of sub-cellular stress. Differences in HSP70 expression pattern were observed between <span class="hlt">vent</span> <span class="hlt">sites</span>, typified by different depths/toxicity profiles, and between different mussel tissue types. A comparison of specimens collected by remote operated vehicle (ROV) and acoustically-operated cages showed that less stress (as indicated by changes in HSP70 levels) was induced by the faster cage recovery method. Therefore alternatives to ROV collection should be considered when planning experiments involving live deep sea organisms. Significantly, a positive correlation was found between the levels of DNA strand breakage, as measured using the Comet assay, and HSP70 expression pattern; evidence was also obtained for the constitutive expression of at least one HSP isoform which was located within the cell nucleus. PMID:17316784</p> <div class="credits"> <p class="dwt_author">Pruski, A M; Dixon, D R</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">178</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1392889"> <span id="translatedtitle">Host-Symbiont Relationships in <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Gastropods of the Genus Alviniconcha from the Southwest Pacific</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> gastropods of the genus Alviniconcha are unique among metazoans in their ability to derive their nutrition from chemoautotrophic ?- and ?-proteobacterial endosymbionts. Although host-symbiont relationships in Alviniconcha gastropods from the Central Indian Ridge in the Indian Ocean and the Mariana Trough in the Western Pacific have been studied extensively, host-symbiont relationships in Alviniconcha gastropods from the Southwest Pacific remain largely unknown. Phylogenetic analysis using mitochondrial cytochrome c oxidase subunit I gene sequences of host gastropods from the Manus, North Fiji, and Lau Back-Arc Basins in the Southwest Pacific has revealed a new host lineage in a Alviniconcha gastropod from the Lau Basin and the occurrence of the host lineage Alviniconcha sp. type 2 in the Manus Basin. Based on 16S rRNA gene sequences of bacterial endosymbionts, two ?-proteobacterial lineages and one ?-proteobacterial lineage were identified in the present study. The carbon isotopic compositions of the biomass and fatty acids of the gastropod tissues suggest that the ?- and ?-proteobacterial endosymbionts mediate the Calvin-Benson cycle and the reductive tricarboxylic acid cycle, respectively, for their chemoautotrophic growth. Coupling of the host and symbiont lineages from the three Southwest Pacific basins revealed that each of the Alviniconcha lineages harbors different bacterial endosymbionts belonging to either the ?- or ?-Proteobacteria. The host specificity exhibited in symbiont selection provides support for the recognition of each of the host lineages as a distinct species. The results from the present study also suggest the possibility that Alviniconcha sp. types 1 and 2 separately inhabit <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> approximately 120 m apart in the North Fiji Basin and 500 m apart in the Manus Basin.</p> <div class="credits"> <p class="dwt_author">Suzuki, Yohey; Kojima, Shigeaki; Sasaki, Takenori; Suzuki, Masae; Utsumi, Takashi; Watanabe, Hiromi; Urakawa, Hidetoshi; Tsuchida, Shinji; Nunoura, Takuro; Hirayama, Hisako; Takai, Ken; Nealson, Kenneth H.; Horikoshi, Koki</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">179</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/10593618"> <span id="translatedtitle">Effect of ambient oxygen concentration on activities of enzymatic antioxidant defences and aerobic metabolism in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> worm, Paralvinella grasslei</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The alvinellid Paralvinella grasslei is a common endemic polychaete from the deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> communities located on the East Pacific Rise (EPR). These organisms colonise a large range of microhabitats around active <span class="hlt">sites</span> where physico-chemical conditions are thought to generate reactive oxygen species (ROS). Furthermore, in this aerobic organism, ROS could also be generated by the activity of the mitochondrial</p> <div class="credits"> <p class="dwt_author">Benjamin Marie; Bertrand Genard; Jean-François Rees; Franck Zal</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">180</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ifremer.fr/docelec/doc/2003/publication-883.pdf"> <span id="translatedtitle">Review of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp genus Mirocaris, redescription of M. fortunata and reassessment of the taxonomic status of the family Alvinocarididae (Crustacea: Decapoda: Caridea)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp genus Mirocaris is reviewed. Morphological comparison between the two nominal species in the genus, M. fortunata and M. keldyshi, was made based on the re-examination of the holotype and paratypes of Mirocaris fortunata and the paratypes of M. keldyshi. Samples newly collected from various <span class="hlt">sites</span> on the Mid-Atlantic Ridge were also examined. The validity of the</p> <div class="credits"> <p class="dwt_author">Tomoyuki KOMAI; Michel SEGONZAC</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_8");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a 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onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_11");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">181</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014EGUGA..16.8108D"> <span id="translatedtitle">Carbon fluxes from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> off Milos, Aegean Volcanic Arc, and the influence of <span class="hlt">venting</span> on the surrounding ecosystem.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The island of Milos, in the Aegean Sea, has extensive <span class="hlt">hydrothermal</span> fields to the east and southeast of the island with additional <span class="hlt">venting</span> areas near the entrance to and within the central caldera. A calculation of the total area of the <span class="hlt">vent</span> fields, based on ship and aerial surveys, suggested that the <span class="hlt">hydrothermal</span> fields occupy 70 km2, twice the area previously estimated. The <span class="hlt">vents</span> ranged in water depth from the intertidal to 300 m. As a result of the low depths there was abundant free gas release: in places water boiled on the seabed. The stream of gas bubbles rising through the sandy seabed drove a shallow re-circulation of bottom seawater. The majority of the water released with the gas, with a mean pH of 5.5, was re-circulated bottom water that had become acidified in contact with CO2 gas and was often diluted by admixture with the vapour phase from the deeper fluids. The major component of the free gas, 80%, was CO2, with an estimated total flux of 1.5-7.5 x 1012 g a-1. The methane flux, by comparison, was of the order of 1010 g a.-1 Using methane as a tracer it was shown that the major gas export from the <span class="hlt">vents</span> was below the thermocline towards the southwest, in agreement with the prevailing currents. Areas of <span class="hlt">hydrothermal</span> brine seepage occurred between the gas <span class="hlt">vents</span> and occasional brine pools were observed in seabed depressions. Under relatively calm conditions, many of the brine seeps were covered by thick minero-bacterial mats consisting of silica and sulphur and surrounded by mats of diatoms and cyanobacteria. The minerals were not deposited in the absence of bacteria. Storms disrupted the mats, leading to an export of material to the surrounding area. Stable isotope data from sediments and sediment trap material suggested that exported POM was processed by zooplankton. The combined effects of the geothermal heating of the seabed, the large gas flux, variation in the <span class="hlt">venting</span> and the effect of the brine seeps had a dramatic effect on the surrounding ecosystem. The infaunal biomass and diversity were greatly reduced in the vicinity of the <span class="hlt">vents</span> (up to approximately 8 m away from the <span class="hlt">vents</span>) and seagrass cover was absent from the brine seeps. These changes were a consequence of high sediment temperatures, hydrogen sulphide concentrations, high or low salinities and sediment cementation. In contrast, the species diversity of the hard substrate epibiota surrounding the <span class="hlt">vents</span> was over twice as high as that at nearby areas of equivalent water depth, even though <span class="hlt">vent</span>-obligate fauna were absent. Sediment cementation, caused by reactions with the minerals in the <span class="hlt">vent</span> fluids, decreased the habitat for sediment infauna, but enhanced bioconstruction by coralline algae and corals, and hence habitat provision for epibenthic organisms. Since the water column was typical of the oligotrophic Aegean, with low chlorophyll and phytoplankton production, the diverse and enhanced benthic primary production, by cyanobacteria, diatoms and chemoautotropic bacteria and archaea, in the mats over the hot seeps was believed to provide a large diversity of nutritional niches for the epibenthos.</p> <div class="credits"> <p class="dwt_author">Dando, Paul; Aliani, Stefano; Bianchi, Nike; Kennedy, Hilary; Linke, Peter; Morri, Carla</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">182</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002AGUFM.T11C1261Y"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Plume Discovery and Survey with an Autonomous Underwater Vehicle</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Autonomous Underwater Vehicles (AUVs) can detect and localize deep sea <span class="hlt">hydrothermal</span> plumes, and through the use of on-board intelligence have the potential to significantly improve the efficiency of plume search. The Autonomous Benthic Explorer has encountered both previously known and newly discovered <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in a variety of settings, including the East Pacific Rise (9°N and 18°S), the Juan de Fuca Ridge (47° 54'N), several <span class="hlt">sites</span> along the Galapagos Rift (86°-89°W), and the Explorer Ridge (49° 46'N). Typically, these plumes were encountered during sonar, video, and magnetic survey with the vehicle following the bottom terrain at heights from 6 to 40 meters, which in most cases placed the vehicle in the rising, buoyant portion of the plume. Typical instruments carried aboard the vehicle include CTD and optical backscatter, and ABE has also carried an acoustic current meter and a redox potential sensor. AUVs have great potential for efficiently locating <span class="hlt">vent</span> <span class="hlt">sites</span>. Unlike ship-towed CTDs, ROVs or manned submersibles, AUVs are uniquely suited to carrying out systematic, exhaustive search patterns. The addition of on-board intelligence, allowing the vehicle to alter its survey track based on sensor data, can greatly improve the yield from an AUV dive. For example, after detecting a plume, the vehicle could break off from its broad area survey and perform a fine grid, possibly at different heights off bottom. But before we can take advantage of this potential, we must understand how an AUV "sees" a plume, and how that perspective can change for different types of <span class="hlt">vents</span> in different settings. Our experience with ABE indicates that a successful autonomous plume survey must be based on a detailed understanding of plume physics. The plumes encountered by ABE in these surveys varied widely in terms of the magnitude of their fluid and thermal output, topographic setting, and ambient currents. The AUV-based observations of these plumes also varied widely, and these observations shed considerable light on the use of AUVs to autonomously detect and localize plumes. The Main Endeavor plumes were surveyed at a height of 70 meters off bottom and showed temperature anomalies up to 500 millidegrees, intense optical backscatter signals, and vertical velocities up to 25 cm/s. These velocities were sufficiently strong that they could be measured with a current meter carried on the vehicle or inferred through their effect on the vertical dynamics of the vehicle. At another extreme, at the Galapagos Rift, ABE surveyed a plume (ALR/3791<span class="hlt">Vent</span>) with temperature anomalies as small as 20 millidegrees, and no optical backscatter signal or discernable vertical velocity at a height of 40 meters. This smaller plume was ground-truthed by observations from the deep submersible Alvin. Finally, ABE surveyed the Calyfield on the Galapagos Rift shortly after its discovery by Alvin and observed little or no anomaly. As Calyfield is certainly more vigorous than the ALR/3791 <span class="hlt">vent</span>, the lack of a discernable signature while surveying in the same manner that located the ALR/3791<span class="hlt">vent</span> is noteworthy. This is most likely due to the complex hydrographic setting of the shallower Calyfield environment, including strong and variable tidal currents over abrupt topography and the presence of multiple water masses. These results will be compared to other plume prospecting techniques applied in the Galapagos including classical CTD tow-yo's and a CTD-instrumented towed camera sled.</p> <div class="credits"> <p class="dwt_author">Yoerger, D. R.; Collier, R.; Bradley, A. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">183</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22503949"> <span id="translatedtitle">Spatial and temporal variations in food web structure from newly-opened habitat at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">To highlight the spatio-temporal variability of the food web structure of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fauna from newly-opened habitat, a series of Titanium Ring for Alvinellid Colonization devices (TRACs) was deployed at TICA <span class="hlt">site</span> on the East Pacific Rise in 2006. This experiment was conducted for periods of 4 days, 13 days and one month and deployments were aligned along a gradient from the basaltic bottom to the <span class="hlt">vent</span> openings. ?(13)C values of colonists revealed a narrower range of carbon sources in proximity to <span class="hlt">vent</span> openings in Alvinella pompejana habitat than in Tevnia jerichonana habitat, separated by a distance of four meters. This was possibly due to a spatial change in available food sources with a possible higher contribution of particulate organic matter (POM) to the siboglinid habitat compared to a higher contribution of microbial primary producers such as Epsilonproteobacteria in the alvinellid habitat. Temporal variability was also observed during experimentation in the form of a shift in either ?(13)C and/or ?(15)N values for A. pompejana, Lepetodrilus elevatus, dirivultid copepods and polynoid polychaetes within a one-month window showing first of all, fast tissues turnover and secondly, a possible switch in feeding strategy or food sources. Lepidonotopodium riftense and Branchinotogluma sandersi may have to alternate between detritivorous and predatory feeding strategies. In addition, through the analysis of stable isotope composition of A. pompejana and its episymbionts, we provided evidence that these attached bacteria formed part of the worms' diet during the course of these colonization experiments. PMID:22503949</p> <div class="credits"> <p class="dwt_author">Gaudron, Sylvie Marylène; Lefebvre, Sébastien; Nunes Jorge, Amandine; Gaill, Françoise; Pradillon, Florence</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">184</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014EGUGA..1612092D"> <span id="translatedtitle">Melt Supply, Crustal Structure, Tectonic Rifting, and <span class="hlt">Hydrothermal</span> <span class="hlt">Venting</span> at the Rainbow Area, 36°N MAR</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The MARINER (Mid-Atlantic Ridge INtegrated Experiments at Rainbow) seismic and geophysical mapping experiment was designed to examine the relationship between tectonic rifting, heat/melt supply, and oceanic core complex formation along the Mid-Atlantic Ridge at 36° N, the <span class="hlt">site</span> of the Rainbow core complex and <span class="hlt">hydrothermal</span> system. The 5-week experiment was carried out aboard the R/V M. G. Langseth in April-May 2013, and consisted of a 3D active-source seismic tomography experiment, a quasi-3D multi-channel seismic experiment, a 9-month seismicity study using seafloor instruments, dense acoustic mapping of the seafloor, gravity field mapping, and magnetic field mapping. During the tomography experiment, we deployed 46 ocean bottom seismometers in a grid pattern centered on Rainbow. Twenty-six seismic lines were carried out using the Langseth's 36-element source, generating 175,000 seismic records. Overall, the experiment extended across two sections of the Mid-Atlantic Ridge separated by the Rainbow core complex (an 80x105 sq. km area). MARINER seismic, gravity, bathymetry, and acoustic imagery data provide both broad and detailed views of the geologic and geophysical character of the ridge system, emphasizing the strong variability of ridge morphology, tectonics, and lava emplacement. The data indicate that the Rainbow area has been the <span class="hlt">site</span> of low magma supply for over 1 Myr. The seismic tomography images reveal undulations in crustal structure and thickness across the Rainbow area, indicating temporal variations in melt supply, magmatic processes, and crustal construction. Patterns of seismic anisotropy, which arise from aligned cracks in the subsurface due to tension, suggest a broad semi-circular region of heavily cracked crust surrounding the Rainbow massif, that focuses upwards to a narrow chimney below the Rainbow <span class="hlt">vent</span> field, potentially indicating the recharge and discharge zones for <span class="hlt">hydrothermal</span> circulation. The current heat source for the <span class="hlt">vents</span> may be a small melt lens intruded below the Rainbow massif (as suggested by reflection data), but the tomography does not indicate a significant magmatic system or high-temperature region beneath the Rainbow area. Only one area shows evidence for a ridge-centered high-temperature region at shallow depth, but it occurs beneath the southern ridge section and many kilometers south of the <span class="hlt">vent</span> field.</p> <div class="credits"> <p class="dwt_author">Dunn, Robert; Canales, J. Pablo; Sohn, Robert; Arai, Ryuta; Paulatto, Michele</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">185</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003EAEJA.....4666S"> <span id="translatedtitle">Evidence of off-axis volcanism and <span class="hlt">hydrothermal</span> <span class="hlt">venting</span> along the cleft segment of the southern Juan de Fuca Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">High-resolution mapping and systematic ROV-based geological observation and sampling, of the Cleft Segment, Juan de Fuca Ridge, provide a unique perspective on crustal evolution and off-axis <span class="hlt">hydrothermal</span> activity along this moderate spreading-rate ridge. Simrad EM300 multibeam bathymetric maps with a 30- m pixel size provide sufficiently high resolution to trace magmatic, tectonic, and <span class="hlt">hydrothermal</span> events over geologically short time scales (50--100,000 years). During a series of 13 dives in 2000 and 2002 using the MBARI ROV Tiburon, we collected samples of basalt and <span class="hlt">hydrothermal</span> precipitates along six transects across the ridge axis extending up to 5 km off-axis. The rift-valley walls consist of a series of inward-facing bounding faults, separated by blocks of oceanic crust that exhibit little or no deformation. Unlike the axial valley where sheetflows are predominant, these off-axis blocks are unfaulted constructional pillow ridges, mounds, and hornitos. Field observations provide evidence for off-axis volcanism along eruptive fissures and from point-sources related to rift-bounding faults. Other volcanic constructions in the first series of abyssal hills are interpreted to be syntectonic lava flows erupted along "volcanic growth faults". Thick ridge-flank flows of intact pillows originated from near-axis bounding faults. The contact between the massive pillowed units and the older sheet flows (approximately three kilometers to the east) is clearly delineated by both sediment cover and lava-flow morphology and is the <span class="hlt">site</span> of diffusive low-temperature <span class="hlt">hydrothermal</span> <span class="hlt">venting</span>. Measured temperatures of shimmering fluids at this eastern <span class="hlt">site</span> were 3--20^oC above ambient. A large Fe-Mn mound with dramatic chemical gradients was discovered 4 km west of the spreading axis on the flank of a ridge-parallel horst capped with syntectonic pillowed flows. The <span class="hlt">hydrothermal</span> mounds are characterized by layered flocculent masses of microbial filaments encrusted with amorphous and poorly crystalline Fe oxyhydroxides and silicates intermixed with pelagic debris. The greenish Fe-, Si-, and microbial-rich layers are capped by successive cm-thick layers of colloform <span class="hlt">hydrothermal</span> Mn oxide. SEM images of microbial sheaths and stalks from precipitates at off-axis <span class="hlt">hydrothermal</span> <span class="hlt">sites</span> are similar in morphology to known Fe-oxidizing bacteria. The low-temperature <span class="hlt">vents</span> may represent secondary <span class="hlt">hydrothermal</span> systems associated with off-axis volcanic episodes. Alternatively, they may represent the distal outflow of high-temperature <span class="hlt">hydrothermal</span> fluids channeled laterally for several kilometers beneath off-axis volcanic units.</p> <div class="credits"> <p class="dwt_author">Stakes, D.; Perfit, M.; Wheat, C.; Ramirez, T.; Koski, R.; Hein, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">186</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.com.univ-mrs.fr/~boudouresque/Master_Oceanographie_Biologie_Ecologie_Marine/Cours_BENT_Chevaldonne_pub_Jenkins.pdf"> <span id="translatedtitle">The digestive system of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> polychaete Galapagomystides aristata (Phyllodocidae): evidence for hematophagy?</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Anatomical, histological, and ultrastructural investigation of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> phyllodocid Galupagomystides aristata shows that this unusual polychaete has a normal mouth and foregut but a highly modified midgut with a blood-filled lumen. The foregut includes a protrusible proboscis armed distally with minute spines. Midgut tissues contain concentrically banded spherocrystals, composed mainly of iron, phosphorus, and silicon, and abundant lipid droplets.</p> <div class="credits"> <p class="dwt_author">Cheryl D. Jenkins; Megan E. Ward; Mary Turnipseed; Joshua Osterberg; Cindy Lee Van Dover</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">187</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/51846642"> <span id="translatedtitle">Longterm monitoring of pressure, tilt and temperature at Logatchev <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Field, Mid-Atlantic Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The geophysical parameters of pressure, tilt, acceleration and temperature at the Logatchev <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Field (LHF) which is located in 3050m water depth at about 15Ë? N at the Mid-Atlantic Ridge, were monitored with high resolution for more than two and a half years, from May 2005 until December 2007. An autonomously operating Ocean Bottom Pressure Station (OBP; resolution of</p> <div class="credits"> <p class="dwt_author">H. W. Villinger; H.-H. Gennerich; M. Fabian</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">188</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/53986802"> <span id="translatedtitle">A Retrievable Mineral Microcosm for Examining Microbial Colonization and Mineral Precipitation at Seafloor <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Although seafloor <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> environments are known to support thriving ecosystems, the microscale physical and chemical environment suitable for microbial colonization and the identity of pioneering organisms is unknown. Because of the fragility of young chimneys and their ephemeral nature, novel methods for sample retrieval and analysis are required. The mineral microcosm consists of four titanium mesh chambers containing crushed</p> <div class="credits"> <p class="dwt_author">E. E. Dunn; J. R. Holloway; S. Cary; K. M. Voglesonger; D. A. Ashbridge; P. A. O'Day</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">189</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/dv05e953jn8903fd.pdf"> <span id="translatedtitle">Genetic heterogeneity among New Zealand species of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussels (Mytilidae: Bathymodiolus )</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Molecular systematic studies provide evidence for three new species of Bathymodiolus-like <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussels (Bivalvia: Mytilidae) from relatively shallow waters (depth less than 750 m) associated with the Kermadec Arc off northern New Zealand. Mitochondrial COI sequences from the three putative new species differed substantially from those of other known bathymodiolin species from the Pacific and Indian Oceans. Population genetic analysis</p> <div class="credits"> <p class="dwt_author">P. J. Smith; S. M. McVeagh; Y. Won; R. C. Vrijenhoek</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">190</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/5384822455t83214.pdf"> <span id="translatedtitle">Post-capture investigations of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> macro-invertebrates to study adaptations to extreme environments</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Typical survival strategies, developed by macro-invertebrates at a variety of reducing marine habitats including deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, have been the subject of the laboratory experimentation over the past three decades. This review provides an insight into the international efforts that have converged on the area of laboratory maintenance of such species whose nutritional requirements are outside the usual scope of</p> <div class="credits"> <p class="dwt_author">Eniko Kadar; Jonathan J. Powell</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">191</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41000825"> <span id="translatedtitle">Detoxification mechanisms in shrimp: Comparative approach between <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields and estuarine environments</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> are extreme deep-sea habitats that, due to their singular features, still intrigue scientific communities. Swift growth rates and profuse biomass of biological communities can be observed, despite of their inherently unstable physical–chemical and toxic conditions, indicating that organisms inhabiting this environment must be well adapted to these inhospitable conditions. The caridean shrimp, Chorocaris chacei, Mirocaris fortunata and Rimicaris</p> <div class="credits"> <p class="dwt_author">Maria Gonzalez-Rey; Angela Serafim; Tânia Gomes; Maria João Bebianno</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">192</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://atiniui.nhm.org/pdfs/11509/11509.pdf"> <span id="translatedtitle">Are midwater shrimp trapped in the craters of submarine volcanoes by <span class="hlt">hydrothermal</span> <span class="hlt">venting</span>?</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The biology of Kick’em Jenny (KEJ) submarine volcano, part of the Lesser Antilles volcanic arc and located off the coast of Grenada in the Caribbean Sea, was studied during a cruise in 2003. <span class="hlt">Hydrothermal</span> <span class="hlt">venting</span> and an associated biological assemblage were discovered in the volcanic crater (?250m depth). Warm water with bubbling gas emanated through rock fissures and sediments. Shrimp</p> <div class="credits"> <p class="dwt_author">Karen F. Wishner; Jason R. Graff; Joel W. Martin; S. Carey; H. Sigurdsson; B. A. Seibel</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">193</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFMOS22B..01B"> <span id="translatedtitle">On the global distribution of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields: One decade later</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Since the last global compilation one decade ago, the known number of active submarine <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields has almost doubled. At the end of 2009, a total of 518 active <span class="hlt">vent</span> fields was catalogued, with about half (245) visually confirmed and others (273) inferred active at the seafloor. About half (52%) of these <span class="hlt">vent</span> fields are at mid-ocean ridges (MORs), 25% at volcanic arcs, 21% at back-arc spreading centers (BASCs), and 2% at intra-plate volcanoes and other settings. One third are in high seas, and the nations with the most known active <span class="hlt">vent</span> fields within EEZs are Tonga, USA, Japan, and New Zealand. The increase in known <span class="hlt">vent</span> fields reflects a number of factors, including increased national and commercial interests in seafloor <span class="hlt">hydrothermal</span> deposits as mineral resources. Here, we have comprehensively documented the percentage of strike length at MORs and BASCs that has been systematically explored for <span class="hlt">hydrothermal</span> activity. As of the end of 2009, almost 30% of the ~60,000 km of MORs had been surveyed at least with spaced vertical profiles to detect <span class="hlt">hydrothermal</span> plumes. A majority of the <span class="hlt">vents</span> discovered at MORs in the past decade occurred at segments with < 60 mm/yr full spreading rate. Discoveries at ultra-slow MORs in the past decade included the deepest known <span class="hlt">vent</span> (Beebe at Mid-Cayman Rise) and high-temperature black smoker <span class="hlt">vents</span> (e.g., Dragon at SWIR and Loki's Castle at Mohns Ridge), and the highest temperature <span class="hlt">vent</span> was measured at the slow-spreading S MAR (Turtle Pits). Using a previously published equation for the linear relationship between the number of active <span class="hlt">vent</span> fields per 100 km strike length (F_s) vs. weighted-average full spreading rate (u_s), we predicted 676 <span class="hlt">vent</span> fields remaining to be discovered at MORs. Even accounting for the lower F_s at slower spreading rates, almost half of the <span class="hlt">vents</span> that are predicted remaining to be discovered at MORs are at ultra-slow to slow spreading rates (< 40 mm/yr) and about 1/3 at intermediate rates (40-80 mm/yr). MOR regions that are little explored tend to be at high latitudes, such as the ultra-slow to slow spreading Arctic MORs (e.g., Kolbeinsey and Mohns Ridges), the ultra-slow American-Antarctic Ridge, and the intermediate spreading Pacific-Antarctic Ridge. Although a greater percentage of the ~11,000 km of BASCs has been surveyed for <span class="hlt">hydrothermal</span> activity, the discoveries at BASCs in the past decade were mainly at segments with intermediate to fast spreading rates. Using the same equation for F_s vs. u_s, we predicted 71 <span class="hlt">vent</span> fields remaining to be discovered at BASCs, and most are likely to be found at ultra-slow and slow spreading segments (e.g., Andaman Basin, and central to northern Mariana Trough). With 2/3 of our overall predicted total <span class="hlt">vent</span> fields at spreading ridges remaining to be discovered, we expect that the next decade of exploration will continue to yield new discoveries, leading to new insights into biogeography of <span class="hlt">vent</span> fauna and the global impacts of fluxes of heat and materials from <span class="hlt">vents</span> into our oceans.</p> <div class="credits"> <p class="dwt_author">Beaulieu, S. E.; Baker, E. T.; German, C. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">194</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3647119"> <span id="translatedtitle">The pH and pCO2 dependence of sulfate reduction in shallow-sea <span class="hlt">hydrothermal</span> CO2 - <span class="hlt">venting</span> sediments (Milos Island, Greece)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Microbial sulfate reduction (SR) is a dominant process of organic matter mineralization in sulfate-rich anoxic environments at neutral pH. Recent studies have demonstrated SR in low pH environments, but investigations on the microbial activity at variable pH and CO2 partial pressure are still lacking. In this study, the effect of pH and pCO2 on microbial activity was investigated by incubation experiments with radioactive 35S targeting SR in sediments from the shallow-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> system of Milos, Greece, where pH is naturally decreased by CO2 release. Sediments differed in their physicochemical characteristics with distance from the main <span class="hlt">site</span> of fluid discharge. Adjacent to the <span class="hlt">vent</span> <span class="hlt">site</span> (T ~40–75°C, pH ~5), maximal sulfate reduction rates (SRR) were observed between pH 5 and 6. SR in <span class="hlt">hydrothermally</span> influenced sediments decreased at neutral pH. Sediments unaffected by <span class="hlt">hydrothermal</span> <span class="hlt">venting</span> (T ~26°C, pH ~8) expressed the highest SRR between pH 6 and 7. Further experiments investigating the effect of pCO2 on SR revealed a steep decrease in activity when the partial pressure increased from 2 to 3 bar. Findings suggest that sulfate reducing microbial communities associated with <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> system are adapted to low pH and high CO2, while communities at control <span class="hlt">sites</span> required a higher pH for optimal activity.</p> <div class="credits"> <p class="dwt_author">Bayraktarov, Elisa; Price, Roy E.; Ferdelman, Timothy G.; Finster, Kai</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">195</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://dx.doi.org/10.1016/j.rgg.2006.04.001"> <span id="translatedtitle">Bottom sediments and pore waters near a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> in Lake Baikal (Frolikha Bay)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">We discuss the redox environments and the compositions of bottom sediments and sedimentary pore waters in the region of a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> in Frolikha Bay, Lake Baikal. According to our results, the submarine <span class="hlt">vent</span> and its companion nearby spring on land originate from a common source. The most convincing evidence for their relation comes from the proximity of stable oxygen and hydrogen isotope compositions in pore waters and in the spring water. The isotope composition indicates a meteoric origin of pore waters, but their major- and minor-element chemistry bears imprint of deep water which may seep through permeable faulted crust. Although pore waters near the submarine <span class="hlt">vent</span> have a specific enrichment in major and minor constituents, <span class="hlt">hydrothermal</span> discharge at the Baikal bottom causes a minor impact on the lake water chemistry, unlike the case of freshwater geothermal lakes in the East-African Rift and North America. ?? 2007.</p> <div class="credits"> <p class="dwt_author">Granina, L. Z.; Klerkx, J.; Callender, E.; Leermakers, M.; Golobokova, L. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">196</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23091033"> <span id="translatedtitle">Evidence for the role of endosymbionts in regional-scale habitat partitioning by <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> symbioses.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> are populated by dense communities of animals that form symbiotic associations with chemolithoautotrophic bacteria. To date, our understanding of which factors govern the distribution of host/symbiont associations (or holobionts) in nature is limited, although host physiology often is invoked. In general, the role that symbionts play in habitat utilization by <span class="hlt">vent</span> holobionts has not been thoroughly addressed. Here we present evidence for symbiont-influenced, regional-scale niche partitioning among symbiotic gastropods (genus Alviniconcha) in the Lau Basin. We extensively surveyed Alviniconcha holobionts from four <span class="hlt">vent</span> fields using quantitative molecular approaches, coupled to characterization of high-temperature and diffuse <span class="hlt">vent</span>-fluid composition using gastight samplers and in situ electrochemical analyses, respectively. Phylogenetic analyses exposed cryptic host and symbiont diversity, revealing three distinct host types and three different symbiont phylotypes (one ?-proteobacteria and two ?-proteobacteria) that formed specific associations with one another. Strikingly, we observed that holobionts with ?-proteobacterial symbionts were dominant at the northern fields, whereas holobionts with ?-proteobacterial symbionts were dominant in the southern fields. This pattern of distribution corresponds to differences in the <span class="hlt">vent</span> geochemistry that result from deep subsurface geological and geothermal processes. We posit that the symbionts, likely through differences in chemolithoautotrophic metabolism, influence niche utilization among these holobionts. The data presented here represent evidence linking symbiont type to habitat partitioning among the chemosynthetic symbioses at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and illustrate the coupling between subsurface geothermal processes and niche availability. PMID:23091033</p> <div class="credits"> <p class="dwt_author">Beinart, Roxanne A; Sanders, Jon G; Faure, Baptiste; Sylva, Sean P; Lee, Raymond W; Becker, Erin L; Gartman, Amy; Luther, George W; Seewald, Jeffrey S; Fisher, Charles R; Girguis, Peter R</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-11-20</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">197</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003EAEJA....11202U"> <span id="translatedtitle">Molecular isotopic evidence for anaerobic oxidation of methane in deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> environment in Okinawa Trough</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Large amount of methane in anoxic marine sediments as well as cold seeps and <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> is recycled through for an anoxic oxidation of methane processes. Now that combined results of field and laboratory studies revealed that microbiological activity associated with syntrophic consortium of archaea performing reversed methanogenesis and sulfate-reducing bacteria is significant roles in methane recycling, anaerobic oxidation of methane (AOM). In this study, we examined the diversity of archaeal and bacterial assemblages of AOM using compound-specific stable carbon isotopic and phylogenetic analyses. "Iheya North" in Okinawa Trough is sediment-rich, back arc type <span class="hlt">hydrothermal</span> system (27^o47'N, 126^o53'E). Sediment samples were collected from three <span class="hlt">sites</span> where are "bubbling <span class="hlt">sites</span>", yellow-colored microbial mats are formed with continuous bubbling from the seafloor bottom, <span class="hlt">vent</span> mussel's colonies <span class="hlt">site</span> together with slowly <span class="hlt">venting</span> and simmering, and control <span class="hlt">site</span> off 100 m distance from thermal <span class="hlt">vent</span>. This subsea floor structure has important effect in the microbial ecosystem and interaction between their activity and geochemical processes in the subseafloor habitats. Culture-independent, molecular biological analysis clearly indicated the presence of thermophilic methanogens in deeper area having higher temperatures and potential activity of AMOs consortium in the shallower area. AMO is composed with sulfate-reducing bacterial components (Desulfosarcina spp.) and anoxic methane oxidizing archaea (ANME-2). These results were consistent with the results of compound-specific carbon analysis of archaeal biomarkers. They showed extremely depleted 13C contents (-80 ppm ˜ -100 ppm), which also appeared to be capable of directly oxidizing methane.</p> <div class="credits"> <p class="dwt_author">Uchida, M.; Takai, K.; Inagaki, F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">198</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014EGUGA..16..208V"> <span id="translatedtitle">Previously unsuspected dietary habits of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fauna: the bactivorous shrimp Rimicaris hybisae can be carnivorous or even cannibalistic</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Most <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> support productive communities, with chemosynthetic bacteria at the base of the food web. They form a potentially important link in global geochemical cycles. However, few data yet exist on their significance in ocean biogeochemistry and related ecological processes. We present results on the structure of part of the food web around <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> of the Mid-Cayman Rise (MCR), revealing previously unknown life-history traits of the alvinocarid shrimp species Rimicaris hybisae. We also demonstrate that stable carbon isotope ratios (?13C values) are an excellent tracer of trophic positions in these ecosystems, in spite of recent findings arguing otherwise. Two <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields have been described at the ultra-slow spreading ridge of the MCR. These include the world's deepest <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> (Piccard field ~4985 m), which support a food web, which includes bactivorous shrimp and carnivorous anemones. The nearby Von Damm <span class="hlt">vent</span> field (~2300 m) supports a more complex food web, with more primary producers, and probably some influx of photosynthetically produced carbon. Rimicaris hybisae is abundant at both known MCR <span class="hlt">vent</span> fields and shows a high degree of spatial variability in population structure and reproductive features. In previous work it has been considered bactivorous. Large variations in tissue ?13C values remained largely unexplained, and it has been argued that ?13C values are not a good food web tracer in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystems. We observed that shrimp tended to be either in dense aggregations on active chimneys or more sparsely distributed, peripheral shrimp in ambient or near-ambient temperatures. With the hypothesis that varying ?13C values show real differences in food sources between individuals and that shrimp in different locales might have different diets, we collected shrimp from both environments at the Von Damm <span class="hlt">site</span> during E/V Nautilus (NA034, August 2013) and examined their gut contents. Stomach contents of all shrimp from dense aggregations at the Von Damm field (n=18) consisted of white, amorphous material that resembled bacteria. Sparsely distributed peripheral shrimp (~1 m from dense aggregations) had stomachs filled with fragments of crustacean exoskeleton (5/13), a mixture of bacteria-like material and crustacean exoskeleton (3/13), or bacteria-like material only (5/13). We then analyzed the ?13C, ?15N and ?34S compositions of the shrimp gut contents. We show that R. hybisae switches its diet from exclusively chemosynthetic bacteria to crustacea during its life history. This is reflected in dramatically lower ?13C values of shrimp tissues, and slightly elevated ?15N values. To further support our findings, measurements of ?34S values on the same individuals and their gut contents are ongoing. Our contribution to disentangling the food web around the MCR <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> fields helps quantify their carbon budget and determine their role in ocean carbon cycling.</p> <div class="credits"> <p class="dwt_author">Versteegh, Emma; Van Dover, Cindy; Coleman, Max</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">199</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003AGUFM.T32A0920W"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> <span class="hlt">Venting</span> in the Southern Most Portion of the Mariana Backarc Spreading Center at 12.57 Degrees N</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The southernmost portion of the Mariana Trough is a complex zone of deformation and magmatism. The centerpiece of the trough is the Malaguana-Gadao Spreading Center Ridge, which has a morphology that is inflated relative to all of the other spreading segments in the Mariana Backarc Basin. This inflated morphology is similar to that of the EPR and is consistent with a high rate of eruption. Samples of lavas from the spreading center are island arc tholeiites, which typically contain higher concentrations of CO2 relative to MORBs. In February 2003 the NOAA <span class="hlt">VENTS</span> program conducted two CTD tow-yos in this area, revealing a <span class="hlt">hydrothermal</span> plume consistent with the presence of a high temperature <span class="hlt">hydrothermal</span> <span class="hlt">site</span>. In May 2003 we used the ROV Jason II to survey a <span class="hlt">hydrothermal</span> <span class="hlt">site</span> at 12 degrees 57.214'N, 143 degrees 37.147'E in a water depth of ~2860 m. Here we collected <span class="hlt">vent</span> fluids, sulfides, basalt, microbial mats, and macrofauna. Two styles of <span class="hlt">venting</span> were identified within an 80 m by 70 m area. Higher temperature <span class="hlt">venting</span> was located in cracks among extinct mounds that were 2-5 m high and wide and are nearly monomineralic (sphalerite) in composition. The exterior is soft and vuggy in contrast to the interior that has crystalline layers with bladed habit lining the orifices. Maximum temperatures of 248 degrees C were recorded 30 cm into these cracks, which were covered with abundant large provannid snails, Alvinoconcha Hessleri, and crabs. In contrast, lower temperature diffuse <span class="hlt">venting</span> (77 degrees C) emanated from mounds that have a porous structure that is composed of amorphous iron oxide and opal. These mounds are covered with microbial mats, which exhibit a high degree of biomass as detected by Cyto-13 nucleic acid epifluorescent staining. Filament and amorphous particulate morphotypes are observed in association with microbial cells, but sheaths have not been detected. These mats have a morphology that is similar to that of neutrophilic Fe-oxidizing bacteria. Fluid chemistry is consistent with a single source and with other back-arc derived <span class="hlt">hydrothermal</span> fluids that are enriched in alkalinity relative to bottom seawater. Extrapolated concentrations per kg of seawater are 0 mmol Mg, 36.2 mmol Ca, 7.3 mmol alkalinity, 544 chlorinity, 414 mmol Na, 32.2 mmol K, 0 mmol sulfate, 165 umol Sr, and 575 umol Li. Additional analyses are ongoing.</p> <div class="credits"> <p class="dwt_author">Wheat, C. G.; Fryer, P.; Hulme, S.; Becker, N.; Curtis, A.; Moyer, C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">200</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/57565566"> <span id="translatedtitle">Oogenesis characteristics in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> polychaete Alvinella pompejana</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The morphology of the female genital tract and mechanisms of oogenesis were investigated through light and transmission electron microscopy in the <span class="hlt">vent</span> polychaete Alvinella pompejana. We showed that the genital pore exhibits different morphologies in males and females and can be used for sex identification. The female genital tract consists of two oviducts that contain mature oocytes and spermathecae, which</p> <div class="credits"> <p class="dwt_author">FLORENCE PRADILLON; FRANÇOISE GAILL</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_9");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return 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id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_10");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a 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showDiv("page_12");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">201</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4077841"> <span id="translatedtitle">Comparative Population Structure of Two Deep-Sea <span class="hlt">Hydrothermal-Vent</span>-Associated Decapods (Chorocaris sp. 2 and Munidopsis lauensis) from Southwestern Pacific Back-Arc Basins</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Studies of genetic connectivity and population structure in deep-sea chemosynthetic ecosystems often focus on endosymbiont-hosting species that are directly dependent on chemical energy extracted from <span class="hlt">vent</span> effluent for survival. Relatively little attention has been paid to <span class="hlt">vent</span>-associated species that are not exclusively dependent on chemosynthetic ecosystems. Here we assess connectivity and population structure of two <span class="hlt">vent</span>-associated invertebrates—the shrimp Chorocaris sp. 2 and the squat lobster Munidopsis lauensis—that are common at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in the western Pacific. While Chorocaris sp. 2 has only been observed at <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span>, M. lauensis can be found throughout the deep sea but occurs in higher abundance around the periphery of active <span class="hlt">vents</span> We sequenced mitochondrial COI genes and deployed nuclear microsatellite markers for both species at three <span class="hlt">sites</span> in Manus Basin and either North Fiji Basin (Chorocaris sp. 2) or Lau Basin (Munidopsis lauensis). We assessed genetic differentiation across a range of spatial scales, from approximately 2.5 km to more than 3000 km. Population structure for Chorocaris sp. 2 was comparable to that of the <span class="hlt">vent</span>-associated snail Ifremeria nautilei, with a single seemingly well-mixed population within Manus Basin that is genetically differentiated from conspecifics in North Fiji Basin. Population structure for Munidopsis lauensis was more complex, with two genetically differentiated populations in Manus Basin and a third well-differentiated population in Lau Basin. The unexpectedly high level of genetic differentiation between M. lauensis populations in Manus Basin deserves further study since it has implications for conservation and management of diversity in deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystems.</p> <div class="credits"> <p class="dwt_author">Thaler, Andrew David; Plouviez, Sophie; Saleu, William; Alei, Freddie; Jacobson, Alixandra; Boyle, Emily A.; Schultz, Thomas F.; Carlsson, Jens; Van Dover, Cindy Lee</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">202</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24983244"> <span id="translatedtitle">Comparative Population Structure of Two Deep-Sea <span class="hlt">Hydrothermal-Vent</span>-Associated Decapods (Chorocaris sp. 2 and Munidopsis lauensis) from Southwestern Pacific Back-Arc Basins.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Studies of genetic connectivity and population structure in deep-sea chemosynthetic ecosystems often focus on endosymbiont-hosting species that are directly dependent on chemical energy extracted from <span class="hlt">vent</span> effluent for survival. Relatively little attention has been paid to <span class="hlt">vent</span>-associated species that are not exclusively dependent on chemosynthetic ecosystems. Here we assess connectivity and population structure of two <span class="hlt">vent</span>-associated invertebrates-the shrimp Chorocaris sp. 2 and the squat lobster Munidopsis lauensis-that are common at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in the western Pacific. While Chorocaris sp. 2 has only been observed at <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span>, M. lauensis can be found throughout the deep sea but occurs in higher abundance around the periphery of active <span class="hlt">vents</span> We sequenced mitochondrial COI genes and deployed nuclear microsatellite markers for both species at three <span class="hlt">sites</span> in Manus Basin and either North Fiji Basin (Chorocaris sp. 2) or Lau Basin (Munidopsis lauensis). We assessed genetic differentiation across a range of spatial scales, from approximately 2.5 km to more than 3000 km. Population structure for Chorocaris sp. 2 was comparable to that of the <span class="hlt">vent</span>-associated snail Ifremeria nautilei, with a single seemingly well-mixed population within Manus Basin that is genetically differentiated from conspecifics in North Fiji Basin. Population structure for Munidopsis lauensis was more complex, with two genetically differentiated populations in Manus Basin and a third well-differentiated population in Lau Basin. The unexpectedly high level of genetic differentiation between M. lauensis populations in Manus Basin deserves further study since it has implications for conservation and management of diversity in deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystems. PMID:24983244</p> <div class="credits"> <p class="dwt_author">Thaler, Andrew David; Plouviez, Sophie; Saleu, William; Alei, Freddie; Jacobson, Alixandra; Boyle, Emily A; Schultz, Thomas F; Carlsson, Jens; Van Dover, Cindy Lee</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">203</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011AGUFMOS11B1471L"> <span id="translatedtitle">Zones of life in the subsurface of <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>: A synthesis</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Subsurface microbial communities in Mid-ocean Ridge (MOR) <span class="hlt">hydrothermal</span> systems host a wide array of unique metabolic strategies, but the spatial distribution of biogeochemical transformations is poorly constrained. Here we present an approach that reexamines chemical measurements from diffuse fluids with models of convective transport to delineate likely reaction zones. Chemical data have been compiled from bare basalt surfaces at a wide array of mid-ocean ridge systems, including 9°N, East Pacific Rise, Axial Seamount, Juan de Fuca, and Lucky Strike, Mid-Atlantic Ridge. Co-sampled end-member fluid from Ty (EPR) was used to constrain reaction path models that define diffuse fluid compositions as a function of temperature. The degree of mixing between hot <span class="hlt">vent</span> fluid (350 deg. C) and seawater (2 deg. C) governs fluid temperature, Fe-oxide mineral precipitation is suppressed, and aqueous redox reactions are prevented from equilibrating, consistent with sluggish kinetics. Quartz and pyrite are predicted to precipitate, consistent with field observations. Most reported samples of diffuse fluids from EPR and Axial Seamount fall along the same predicted mixing line only when pyrite precipitation is suppressed, but Lucky Strike fluids do not follow the same trend. The predicted fluid composition as a function of temperature is then used to calculate the free energy available to autotrophic microorganisms for a variety of catabolic strategies in the subsurface. Finally, the relationships between temperature and free energy is combined with modeled temperature fields (Lowell et al., 2007 Geochem. Geophys., Geosys.) over a 500 m x 500 m region extending downward from the seafloor and outward from the high temperature focused <span class="hlt">hydrothermal</span> flow to define areas that are energetically most favorable for a given metabolic process as well as below the upper temperature limit for life (~120 deg. C). In this way, we can expand the relevance of geochemical model predictions of bioenergetics by predicting functionally-defined 'Zones of Life' and placing them spatially within the boundary of the 120 deg. C isotherm, estimating the extent of subsurface biosphere beneath mid-ocean ridge <span class="hlt">hydrothermal</span> systems. Preliminary results indicate that methanogenesis yields the most energy per kg of <span class="hlt">vent</span> fluid, consistent with the elevated CH4(aq) seen at all three <span class="hlt">sites</span>, but may be constrained by temperatures too hot for microbial life while available energy from the oxidation of Fe(II) peaks near regions of the crust that are more hospitable.</p> <div class="credits"> <p class="dwt_author">Larson, B. I.; Houghton, J.; Meile, C. D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">204</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2006GGG.....7.6018G"> <span id="translatedtitle">Geochemical controls on <span class="hlt">hydrothermal</span> fluids from the Kairei and Edmond <span class="hlt">Vent</span> Fields, 23°-25°S, Central Indian Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Prior to 2000, no mid-ocean ridge <span class="hlt">hydrothermal</span> systems were identified and sampled in the Indian Ocean. The Kairei field, Central Indian Ridge, was discovered and sampled in 2000 (Gamo et al., 2001; Hashimoto et al., 2001). This paper reports the chemical composition of <span class="hlt">hydrothermal</span> fluids collected in 2001 from both the Kairei and newly discovered Edmond <span class="hlt">hydrothermal</span> systems. Data are used to infer subsurface processes and conditions at the two <span class="hlt">sites</span>, as well as to place them within the global context of known <span class="hlt">hydrothermal</span> <span class="hlt">sites</span> on the mid-ocean ridge system. While both <span class="hlt">sites</span> are located on the intermediate spreading Central Indian Ridge, their hydrologic systems have affinities with those observed on slow spreading ridges. Although the compositions of fluids from the four individual <span class="hlt">vents</span> sampled at Edmond and the three individual <span class="hlt">vents</span> sampled at Kairei vary respectively, our interpretation is that a single source fluid at each <span class="hlt">site</span> is subsequently modified by processes including phase separation, subsurface mixing with seawater, and deposition and/or remobilization of metal-sulfide deposits to generate the observed range of compositions. Both fields are located ?6 km from the neovolcanic zone, on steps on the east wall of the axial valley, with the Edmond field ˜160 km north of Kairei and almost 1000 m deeper (3300 versus 2450 m). The Edmond fluids are extremely hot, with maximum measured temperatures of 382°C compared to 365°C for Kairei. All of the fluids sampled have chlorinities greater than local ambient seawater due to phase separation of seawater at supercritical conditions. Visual observations suggest both <span class="hlt">sites</span> have been active for a substantial period of time, again similar to observations of slow spreading ridges. Our chemical data suggest that the substrate underlying Kairei is highly altered, while that at Edmond is not. Significant albitization appears to be occurring below the Edmond field, but not at Kairei. The Edmond fluids are by far the hottest brines yet observed <span class="hlt">venting</span> from a mid-ocean ridge <span class="hlt">hydrothermal</span> <span class="hlt">site</span>, resulting in unusually high concentrations of several transition metals.</p> <div class="credits"> <p class="dwt_author">Gallant, R. M.; von Damm, K. L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">205</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004AGUFMGP23A0166L"> <span id="translatedtitle">Magnetic and Electron Microscopic Investigation on Rock Samples from the PACMANUS <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Field in Papua New Guinea</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The PACMANUS <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field in the Eastern Manus back-arc basin, Papua New Guinea, is considered as a modern-day analog of massive volcanogenic sulfide deposits within felsic volcanic sequence. This active <span class="hlt">vent</span> field was drilling in November-December 2003 by Ocean Drilling Program Leg 193. The recovery was generally low with less than 15% due to fragility of rocks. Paleomagnetic measurements and scanning electron microscope observations were performed on samples from three major <span class="hlt">sites</span> (<span class="hlt">Sites</span> 1188, 1189 and 1191). <span class="hlt">Site</span> 1188, a low-temperature diffused <span class="hlt">venting</span> region, was drilled to 370 mbsf. <span class="hlt">Site</span> 1189, a black smoker region, was drilled to a depth of 200 mbsf using RCB. The recovered rock samples have inclination close to the present-day Earth field (-7° ), but those near the seafloor have much steeper inclination of up to -25° . The upper 35 m of the <span class="hlt">sites</span> consists of fresh to moderately altered dacite-rhyodacite, which exhibits moderately high natural remanent magnetization (< 6 A/m). The region below this extrusive layer largely comprises of pervasively altered rocks with little evidence of sulfide deposit and as a whole exhibits a low magnetization intensity. However, two intervals with extremely high remanent magnetization were discovered below the upper extrusive layer at <span class="hlt">Site</span> 1188 (135-211 mbsf and 280-370 mbsf) and one interval at <span class="hlt">Site</span> 1189 (137-190 mbsf). In particular, the samples between 135-211-mbsf interval at <span class="hlt">Site</span> 1188 have extremely high remanence with intensities ranging up to 300-500 A/m. Although pockets of magnetite are not uncommon in the ancient <span class="hlt">hydrothermal</span> ore bodies, they have seldom been documented in modern-day system, and little is known about the physical and chemical condition that allows the magnetite to form in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> systems. Two possibilities of magnetite formation are explored: one that these magnetites precipitated from magnetite-rich fluid as it cooled from above the Curie temperature (TRM) and the other that magnetization was acquired by the growth of magnetite grains below the Curie temperature (CRM).</p> <div class="credits"> <p class="dwt_author">Lee, S.; Doh, S.; Kim, Y.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">206</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014EGUGA..16.1522K"> <span id="translatedtitle">Magnetic characteristics of possible <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in TA 25 and TA26 seamounts, the Lau Basin</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The deep sea three component magnetic survey was conducted in the western (<span class="hlt">site</span> A) and eastern (<span class="hlt">site</span> B) slopes of the caldera of TA25 seamount and the summit area of TA26 seamount, the Lau Basin, the southwestern Pacific, at Jan. 2012, using German R/V SONNE and ROV (Remotely Operated Vehicle) of ROPOS Co. The magnetic survey lines were the 29 N-S lines (TA25-East : 12 lines, TA25-West : 11 lines, TA26 : 6 lines) with about 100 m spacing and about 50 m above seafloor. For the magnetic survey, the magnetometer sensor was attached with the line frame of ROV and the data logger and motion sensor in ROV. A motion sensor (Octans) provided us the data of pitch, roll, yaw for the correction of the magnetic data to the motion of ROV. The data of the magnetometer and motion sensors and the USBL(Ultra Short Base Line) data of the position of ROV were recorded on a notebook through the optical cable of ROV. <span class="hlt">Hydrothermal</span> fluids over Curie temperature can quickly alter or replace the iron-rich magnetic minerals, reducing the magnetic remanence of the crustal rocks, in some cases to near 0 A/m magnetization. The magnetic anomaly map of TA25 <span class="hlt">site</span> A shows high anomalies in the central part and low anomalies in the northern part, ranging from about -500 to 500 nT. The magnetization map, calculated by the inversion of the bathymetry and the magnetic anomaly, represents low anomalous zones over the south-western part and the northern part of the area. The magnetic anomaly map of TA25 <span class="hlt">site</span> B displays high anomalies in the southeastern part and low anomalies in the central and eastern parts, ranging from about -700 to 800 nT. The low magnetization zones occur over the western part and central part of the area. The high magnetic anomalies of the survey area of TA26 are located in the north and northeastern parts and low anomalies in the southeastern part, with the magnetic anomaly range from about -2000 to 1600 nT. The magnetization map shows east-west trend low anomalous zones in the area. The low anomalous magnetization zones of the survey areas usually appear in groups. Some of these low magnetization zones are well matched with the chimney <span class="hlt">sites</span> or <span class="hlt">hydrothermal</span> altered areas, based on the previous results of video or rock sampling. The low magnetization zones are likely to be the possible <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</p> <div class="credits"> <p class="dwt_author">Kim, Chang Hwan; Choi, Soon Young; Park, Chan Hong</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">207</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3522073"> <span id="translatedtitle">Widespread Occurrence of Two Carbon Fixation Pathways in Tubeworm Endosymbionts: Lessons from <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Associated Tubeworms from the Mediterranean Sea</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Vestimentiferan tubeworms (siboglinid polychetes) of the genus Lamellibrachia are common members of cold seep faunal communities and have also been found at sedimented <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> in the Pacific. As they lack a digestive system, they are nourished by chemoautotrophic bacterial endosymbionts growing in a specialized tissue called the trophosome. Here we present the results of investigations of tubeworms and endosymbionts from a shallow <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field in the Western Mediterranean Sea. The tubeworms, which are the first reported <span class="hlt">vent</span>-associated tubeworms outside the Pacific, are identified as Lamellibrachia anaximandri using mitochondrial ribosomal and cytochrome oxidase I (COI) gene sequences. They harbor a single gammaproteobacterial endosymbiont. Carbon isotopic data, as well as the analysis of genes involved in carbon and sulfur metabolism indicate a sulfide-oxidizing chemoautotrophic endosymbiont. The detection of a hydrogenase gene fragment suggests the potential for hydrogen oxidation as alternative energy source. Surprisingly, the endosymbiont harbors genes for two different carbon fixation pathways, the Calvin-Benson-Bassham (CBB) cycle as well as the reductive tricarboxylic acid (rTCA) cycle, as has been reported for the endosymbiont of the <span class="hlt">vent</span> tubeworm Riftia pachyptila. In addition to RubisCO genes we detected ATP citrate lyase (ACL – the key enzyme of the rTCA cycle) type II gene sequences using newly designed primer sets. Comparative investigations with additional tubeworm species (Lamellibrachia luymesi, Lamellibrachia sp. 1, Lamellibrachia sp. 2, Escarpia laminata, Seepiophila jonesi) from multiple cold seep <span class="hlt">sites</span> in the Gulf of Mexico revealed the presence of acl genes in these species as well. Thus, our study suggests that the presence of two different carbon fixation pathways, the CBB cycle and the rTCA cycle, is not restricted to the Riftia endosymbiont, but rather might be common in vestimentiferan tubeworm endosymbionts, regardless of the habitat.</p> <div class="credits"> <p class="dwt_author">Thiel, Vera; Hugler, Michael; Blumel, Martina; Baumann, Heike I.; Gartner, Andrea; Schmaljohann, Rolf; Strauss, Harald; Garbe-Schonberg, Dieter; Petersen, Sven; Cowart, Dominique A.; Fisher, Charles R.; Imhoff, Johannes F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">208</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40471865"> <span id="translatedtitle">Spermatogenesis of Bathymodiolus azoricus in captivity matching reproductive behaviour at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">This study aims to improve our knowledge on the reproduction cycles of\\u000a invertebrates from deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, which is fragmentary to\\u000a date, owing to the prohibitive costs of regular time series sampling\\u000a required for a complete assessment. However, new technologies such as\\u000a acoustically retrievable cages and the long-term laboratory maintenance\\u000a of <span class="hlt">vent</span> species enabled sampling at relatively low costs. Reproductive</p> <div class="credits"> <p class="dwt_author">E Kadar; Alexandre Lobo-da-Cunha; Ricardo S. Santos; Paul Dando</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">209</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2005AGUFM.B21A1008A"> <span id="translatedtitle">Tomography of Bacteria-Mineral Associations Within the Deep sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Shrimp Rimicaris exoculata.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The chemical and temperature conditions around deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> are both dynamic and extreme, yet the shrimp Rimicaris exoculata flourishes around these environments on the Mid-Atlantic Ridge (MAR) . The epibiotic bacteria and minerals found within the branchial chamber of the shrimp are of great interest in the search for a chemical model for the Rainbow MAR <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span>. Here we examine the close three-dimensional (3D) relationship between bacteria (on inner surface of the branchial chamber wall), and the minerals that surround them. The morphology and chemistry of the minerals were analysed by Transmission Electron Microscopy (TEM) and Energy-filtering Transmission Electron Microscopy (EFTEM, LEO 912 Omega) respectively, and the 3D organisation (TOMO) was established using IMAGE-J (public-domain) tomographic reconstruction software. Samples of Rimicaris exoculata were collected from the Rainbow <span class="hlt">site</span> (36° 13' N, 2320 m depth). The cuticle of the branchial chamber was cut into 2mm wide sub-samples, dehydrated and impregnated in resin for cutting. Consecutive thin and semi-thin sections of 80?m (for TEM, EFTEM) and 150?m-200?m (for TOMO) were cut and mounted on standard microscope grids. Thin-section grids were observed initially for morphology, to find broad relationships between bacteria and minerals, and also as a tool to find areas for EFTEM analysis and TOMO. The TOMO reconstruction was produced from a `Tilt Series', comprising a number of images taken at one degree increments between -55° and +55°. Tilt series were obtained using the ESIvision program (Version 3.0, Soft? Imaging Software, SIS GmbH, D-49153 Münster, Germany) with additional in-house scripts for automated acquisition. This same procedure was applied to consecutive semi-thin sections through the same sub-sample. The different series for each sub-sample were then overlain to obtain a 3D overview of the bacteria-mineral associations. In many cases the minerals exhibit a sharp boundary against the bacteria, often with a substantial void between bacterial membrane and mineral boundary. Mineral layering and areas of elemental zoning are also observed. Iron is the most prevalent element, with a close association to the bacteria. Future work will combine the elemental data obtained by EFTEM with tomography to produce a 3D elemental map of the minerals surrounding the bacteria, focussing particularly on the bacteria-mineral interface using recently developed EFTET-J software (http://www.snv.jussieu.fr/~wboudier/softs.html).</p> <div class="credits"> <p class="dwt_author">Anderson, L.; Lechaire, J.; Frebourg, G.; Boudier, T.; Zbinden, M.; Gaill, F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">210</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://decapoda.nhm.org/pdfs/12189/12189.pdf"> <span id="translatedtitle">A deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> community dominated by Stauromedusae</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">A dense population of stauromedusan scyphozoans (morphologically similar to previously described species within the genus Lucernaria) was encountered in a previously undocumented area of <span class="hlt">hydrothermal</span> activity along the crest of the East Pacific Rise (Lat. 20°50.304?N; Long. 109°05.422?W; depth of 2605m). A few galatheid (Munidopsis subsquamosa) and bythograeid (Bythograea thermydron) crabs and occasional anemones (Cyananthea sp.) were the only other</p> <div class="credits"> <p class="dwt_author">Richard A. Lutz; Daniel Desbruyères; Timothy M. Shank; Robert C. Vrijenhoek</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">211</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=92526"> <span id="translatedtitle">Characterization of a Novel Spirochete Associated with the <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Polychaete Annelid, Alvinella pompejana</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">A highly integrated, morphologically diverse bacterial community is associated with the dorsal surface of Alvinella pompejana, a polychaetous annelid that inhabits active high-temperature deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> along the East Pacific Rise (EPR). Analysis of a previously prepared bacterial 16S ribosomal DNA (rDNA) library identified a spirochete most closely related to an endosymbiont of the oligochete Olavius loisae. This spirochete phylotype (spirochete A) comprised only 2.2% of the 16S rDNA clone library but appeared to be much more dominant when the same sample was analyzed by denaturing gradient gel electrophoresis (DGGE) and the terminal restriction fragment length polymorphism procedure (12 to 18%). PCR amplification of the community with spirochete-specific primers used in conjunction with DGGE analysis identified two spirochete phylotypes. The first spirochete was identical to spirochete A but was present in only one A. pompejana specimen. The second spirochete (spirochete B) was 84.5% similar to spirochete A and, more interestingly, was present in the epibiont communities of all of the A. pompejana specimens sampled throughout the geographic range of the worm (13°N to 32°S along the EPR). The sequence variation of the spirochete B phylotype was less than 3% for the range of A. pompejana specimens tested, suggesting that a single spirochete species was present in the A. pompejana epibiotic community. Additional analysis of the environments surrounding the worm revealed that spirochetes are a ubiquitous component of high-temperature <span class="hlt">vents</span> and may play an important role in this unique ecosystem.</p> <div class="credits"> <p class="dwt_author">Campbell, Barbara J.; Cary, S. Craig</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">212</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://pubs.er.usgs.gov/publication/70013515"> <span id="translatedtitle">Biological communities at the Florida Escarpment resemble <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> taxa</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">Dense biological communities of large epifaunal taxa similar to those found along ridge crest <span class="hlt">vents</span> at the East Pacific Rise were discovered in the abyssal Gulf of Mexico. These assemblages occur on a passive continental margin at the base of the Florida Escarpment, the interface between the relatively impermeable hemipelagic clays of the distal Mississippi Fan and the jointed Cretaceous limestone of the Florida Platform. The fauna apparently is nourished by sulfide rich hypersaline waters seeping out at near ambient temperatures onto the sea floor.</p> <div class="credits"> <p class="dwt_author">Paull, C. K.; Hecker, B.; Commeau, R.; Freeman-Lynde, R. P.; Neumann, C.; Corso, W. P.; Golubic, S.; Hook, J. E.; Sikes, E.; Curray, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1984-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">213</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17820171"> <span id="translatedtitle">Percolation Theory, Thermoelasticity, and Discrete <span class="hlt">Hydrothermal</span> <span class="hlt">Venting</span> in the Earth's Crust.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">As <span class="hlt">hydrothermal</span> fluid ascends through a network of cracks into cooler crust, heat is transferred from the fluid to the adjacent rock. The thermal stresses caused by this heating close cracks that are more or less vertical. This heating may affect network connections and destroy the permeable crack network. Thermoelastic stresses caused by a temperature difference of approximately 1000 degrees C can decrease the interconnectivity of a crack network to the percolation threshold. If the temperature is slightly less, thermoelastic stresses may focus the discharge in <span class="hlt">hydrothermal</span> systems into discrete <span class="hlt">vents</span>. PMID:17820171</p> <div class="credits"> <p class="dwt_author">Germanovich, L N; Lowell, R P</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-03-20</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">214</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUFMGP11A..07F"> <span id="translatedtitle">Absolute Magnetization Distribution on Back-arc Spreading Axis Hosting <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span>; Insight from Shinkai 6500 Magnetic Survey</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Near-bottom magnetic profiling using submersible, deep-tow, Remotely Operated Vehicle (ROV) and Autonomous Underwater Vehicle (AUV) make possible to conduct high-resolution surveys and depict detailed magnetic features reflecting, for instance, the presence of fresh lavas or <span class="hlt">hydrothermal</span> alteration, or geomagnetic paleo-intensity variations. We conducted near-bottom three component magnetic measurements onboard submersible Shinkai 6500 in the Southern Mariana Trough, where five active <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields (Snail, Yamanaka, Archean, Pica, and Urashima <span class="hlt">sites</span>) have been found in both on- and off-axis areas of the active back-arc spreading center, to detect signals from <span class="hlt">hydrothermally</span> altered rock and to distinguish old and new submarine lava flows. Fourteen dives were carried out at an altitude of 1-40 m during the R/V Yokosuka YK10-10 and YK10-11 cruises in 2010. We carefully corrected the effect of the induced and permanent magnetizations of the submersible by applying the correction method for the shipboard three-component magnetometer measurement modified for deep-sea measurement, and subtracted the IGRF values from the corrected data to obtain geomagnetic vector anomalies along the dive tracks. We then calculated the synthetic magnetic vector field produced by seafloor, assumed to be uniformly magnetized, using three dimensional forward modeling. Finally, values of the absolute magnetizations were estimated by using a linear transfer function in the Fourier domain from the observed and synthetic magnetic anomalies. The distribution of estimated absolute magnetization generally shows low values around the five <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span>. This result is consistent with the equivalent magnetization distribution obtained from previous AUV survey data. The areas of low magnetization are also consistent with <span class="hlt">hydrothermal</span> deposits identified in video records. These results suggest that low magnetic signals are due to <span class="hlt">hydrothermal</span> alteration zones where host rocks are demagnetized by <span class="hlt">hydrothermal</span> circulation. The low magnetization zones around the off-axis <span class="hlt">vent</span> <span class="hlt">sites</span> are about ten times wider than those surrounding the on-axis <span class="hlt">sites</span>, possibly reflecting the longer duration of <span class="hlt">hydrothermal</span> circulation at these <span class="hlt">sites</span>. Another interesting result is that the absolute magnetization shows extremely high intensities (>80 A/m) at the neo volcanic zones (NVZ) and relatively low intensities (<10 A/m) two to five kilometers away from the NVZ. These variations are quite consistent with those of the Natural Remanent Magnetization measured on basalt samples, suggesting that the low-temperature oxidation of host rock due to the reaction with seawater has completed within a few kilometers distance from the spreading axis. We conclude that the magnetization of the uppermost oceanic crust decreases with age due to the combination of the both <span class="hlt">hydrothermal</span> rapid alteration and the low-temperature gradual alteration processes.</p> <div class="credits"> <p class="dwt_author">Fujii, M.; Okino, K.; Honsho, C.; Mochizuki, N.; Szitkar, F.; Dyment, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">215</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40203071"> <span id="translatedtitle">The effect of cadmium on antioxidant responses and the susceptibility to oxidative stress in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> are a unique environment of extreme physical–chemical characteristics and biological species composition.\\u000a Cd is a toxic non-essential metal present in high concentrations in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> environment, contrary to those found\\u000a in marine coastal areas. Cd toxicity has been related, among other things, with reactive oxygen species production, even though\\u000a this is a non-redox metal. Bathymodiolus azoricus is</p> <div class="credits"> <p class="dwt_author">Angela Serafim; Richard Cosson; Lionel Camus; Bruce Shillito; Aline Fiala-Médioni; Maria João Bebianno</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">216</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/21222464"> <span id="translatedtitle">Bathymodiolamides A and B, ceramide derivatives from a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> invertebrate mussel, Bathymodiolus thermophilus.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Two ceramide derivatives, bathymodiolamides A (1) and B (2), were isolated from the deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> invertebrate mussel Bathymodiolus thermophilus. The molecular structures of these compounds were determined using a combination of NMR spectroscopy, mass spectrometry, and chemical degradation. Biological activities were assessed in a ApopScreen cell-based screen for apoptosis induction and potential anticancer activity. To our knowledge, this is the first report of secondary metabolites from the marine <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel B. thermophilus. PMID:21222464</p> <div class="credits"> <p class="dwt_author">Andrianasolo, Eric H; Haramaty, Liti; McPhail, Kerry L; White, Eileen; Vetriani, Costantino; Falkowski, Paul; Lutz, Richard</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-04-25</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">217</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2001AGUFMOS32C..04E"> <span id="translatedtitle">Hot Springs in a Cold Ocean: Evidence for Abundant <span class="hlt">Hydrothermal</span> <span class="hlt">Venting</span> on the Ultra-Slow Spreading Gakkel Ridge.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Gakkel Ridge, extending through the Eurasian Basin of the Arctic Ocean from north of Greenland to the Laptev Sea, is the slowest spreading mid-ocean ridge on the planet. There has been extensive speculation about crustal generation processes, the presence or absence of extrusive volcanic activity, and high temperature <span class="hlt">hydrothermal</span> <span class="hlt">venting</span> and associated fauna on the Gakkel Ridge, but data have remained scarce due to the relative inaccessibility of the ridge. From the end of July to early October, 2001, a team of scientists aboard the new icebreaker USCGC Healy and the RV Polarstern undertook the first systematic sampling of the Gakkel Ridge, largely for petrological studies. Miniature Autonomous Plume Recorders (MAPRs) were deployed on the trawl wire during dredging and rock coring operations, in order to identify <span class="hlt">sites</span> of <span class="hlt">hydrothermal</span> <span class="hlt">venting</span> through light scattering and temperature anomalies associated with <span class="hlt">hydrothermal</span> plumes. As of August 26, we have surveyed over 200 km of the ridge, from 8 degrees West to 15 degrees East, and identified at least four distinct areas of <span class="hlt">hydrothermal</span> activity: the first ever found on the Gakkel Ridge. The extent of evident <span class="hlt">hydrothermal</span> activity is remarkable, and unexpected in light of previous observations of the covariance between plume incidence (percent of ridge overlain by plumes) and spreading rate. Of 47 successful MAPR deployments so far, 36 show layers of high light scattering, with clearly defined upper and lower boundaries, well above the seafloor. Of these, 14 are large enough to have corresponding temperature anomalies (on the order of 0.01 degrees). Sulfide chimneys have been dredged at one <span class="hlt">site</span>, on the flank of an axial volcanic edifice located near the intersection of the western Gakkel Ridge and Lena Trough. A single CTD cast, performed in a second area identified through three MAPR deployments, reveals that neutrally buoyant <span class="hlt">hydrothermal</span> plumes in the Arctic Ocean exhibit negative anomalies of both potential temperature and salinity, similar to plumes in the Atlantic. Plume water samples have been collected for Mn, methane, and He-3 to confirm the <span class="hlt">hydrothermal</span> nature of the light scattering anomalies and provide some estimate of source strength. Manganese analyses will be completed by the time of this meeting. We plan to sample as far as 85 degrees E, where it is believed a volcanic eruption may have occurred in 1999 (Edwards et al., Nature, 2001). In his life and work, John Edmond encompassed many extremes, including latitude, altitude, temperature and depth. In many ways, his example inspired the present investigation, and will doubtless continue to inspire many more.</p> <div class="credits"> <p class="dwt_author">Edmonds, H. N.; Michael, P. J.; Baker, E. T.; Graham, D. W.; Vock, M.; Snow, J.; Muhe, R.; Connelly, D. P.; German, C. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">218</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013DSRII..92..234S"> <span id="translatedtitle">Thermal adaptations in deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> and shallow-water shrimp</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp Mirocaris fortunata is commonly exposed to acute thermal gradients and rapid fluctuations in water temperature. The shallow-water shrimp Palaemonetes varians experiences less acute but similar magnitude fluctuations in its thermal regime. Acute respiratory response to temperature shock, and temperature preference was assessed for both species. Oxygen consumption rates were assessed across the natural temperature range reported for M. fortunata. Rates increased with temperature for both species. P. varians had a significantly higher rate of oxygen consumption than M. fortunata at all temperatures except 4 °C. The rate of increase in oxygen consumption with increasing temperature was also significantly greater for P. varians. M. fortunata selected a significantly higher temperature than P. varians. Mirocaris fortunata maintains its metabolism at a more stable rate, which is likely an adaptation to acute changes in temperatures occurring at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</p> <div class="credits"> <p class="dwt_author">Smith, Felix; Brown, Alastair; Mestre, Nélia C.; Reed, Adam J.; Thatje, Sven</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-08-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">219</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=134447"> <span id="translatedtitle">Bacterial Group II Introns in a Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Environment†</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Group II introns are catalytic RNAs and mobile retrotransposable elements known to be present in the genomes of some nonmarine bacteria and eukaryotic organelles. Here we report the discovery of group II introns in a bacterial mat sample collected from a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> near 9°N on the East Pacific Rise. One of the introns was shown to self-splice in vitro. This is the first example of marine bacterial introns from molecular population structure studies of microorganisms that live in the proximity of <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. These types of mobile genetic elements may prove useful in improving our understanding of bacterial genome evolution and may serve as valuable markers in comparative studies of bacterial communities.</p> <div class="credits"> <p class="dwt_author">Podar, Mircea; Mullineaux, Lauren; Huang, Hon-Ren; Perlman, Philip S.; Sogin, Mitchell L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">220</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/21856628"> <span id="translatedtitle">Biogeography revisited with network theory: retracing the history of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> communities.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Defining biogeographic provinces to understand the history and evolution of communities associated with a given kind of ecosystem is challenging and usually requires a priori assumptions to be made. We applied network theory, a holistic and exploratory method, to the most complete database of faunal distribution available on oceanic <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, environments which support fragmented and unstable ecosystems, to infer the processes driving their worldwide biogeography. Besides the identification of robust provinces, the network topology allowed us to identify preferential pathways that had hitherto been overlooked. These pathways are consistent with the previously proposed hypothesis of a role of plate tectonics in the biogeographical history of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> communities. A possible ancestral position of the Western Pacific is also suggested for the first time. Finally, this work provides an innovative example of the potential of network tools to unravel the biogeographic history of faunal assemblages and to supply comprehensive information for the conservation and management of biodiversity. PMID:21856628</p> <div class="credits"> <p class="dwt_author">Moalic, Yann; Desbruyères, Daniel; Duarte, Carlos M; Rozenfeld, Alejandro F; Bachraty, Charleyne; Arnaud-Haond, Sophie</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_10");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return 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showDiv("page_13");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">221</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17782446"> <span id="translatedtitle">Growth of bivalves at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> along the galapagos rift.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Direct measurements of shell growth of an unclassified mussel from active <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> along the Galápagos Rift reveal growth rates of approxmately 1 centimeter per year for mature specimens. The largest mussel collected (with shell length of 18.4 centimeters) was estimated to be 19 +/- 7 years old at the time of sampling. Recorded growth rates are among the highest documented for deep-sea species. PMID:17782446</p> <div class="credits"> <p class="dwt_author">Rhoads, D C; Lutz, R A; Revelas, E C; Cerrato, R M</p> <p class="dwt_publisher"></p> <p class="publishDate">1981-11-20</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">222</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41133956"> <span id="translatedtitle">Biotic interactions at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>: Recruitment inhibition by the mussel Bathymodiolus thermophilus</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The structure and dynamics of marine communities are regulated in part by variation in recruitment. As in other ecosystems, recruitment at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> is controlled by the interplay of propagule supply and behavior, gradients in physical–chemical conditions, and biotic interactions during pre- and post-settlement periods. Recent research along the East Pacific Rise indicates that inhibition of recently settled larvae</p> <div class="credits"> <p class="dwt_author">H. S. Lenihan; S. W. Mills; L. S. Mullineaux; C. H. Peterson; C. R. Fisher; F. Micheli</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">223</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/v3lj452740549772.pdf"> <span id="translatedtitle">Genetic diversity and demographic instability in Riftia pachyptila tubeworms from eastern Pacific <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Background  Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> animals occupy patchy and ephemeral habitats supported by chemosynthetic primary production. Volcanic\\u000a and tectonic activities controlling the turnover of these habitats contribute to demographic instability that erodes genetic\\u000a variation within and among colonies of these animals. We examined DNA sequences from one mitochondrial and three nuclear gene\\u000a loci to assess genetic diversity in the siboglinid tubeworm, Riftia</p> <div class="credits"> <p class="dwt_author">D Katharine Coykendall; Shannon B Johnson; Stephen A Karl; Richard A Lutz; Robert C Vrijenhoek</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">224</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/48598066"> <span id="translatedtitle">Microbial Habitats Associated with Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Invertebrates: Insights from Microanalysis and Geochemical Modeling</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">\\u000a Symbioses between <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> invertebrates and chemosynthetic microbes have been recognized to form some of the most\\u000a productive marine communities (Lutz et al. 1994; Halbach et al. 2003). Endosymbiotic organisms, like the giant tubeworm Riftia pachyptila or the Bathymodiolus spp. mussels, flourish in diffuse flow areas of the seafloor. A key to their success is the ability to supply the</p> <div class="credits"> <p class="dwt_author">Nadine Le Bris; Françoise Gaill</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">225</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41000722"> <span id="translatedtitle">Deep sea immunity: Unveiling immune constituents from the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Marine molluscs are subjected to constant microbial threats in their\\u000a natural habitats. As a result, they represent suitable models for the\\u000a study of the molecular mechanisms that govern defense reactions in\\u000a marine organisms. To understand humoral and cellular defense reactions\\u000a in animals defying extreme physical and chemical conditions we set out\\u000a to investigate the deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus</p> <div class="credits"> <p class="dwt_author">Raul Bettencourt; Philippe Roch; Sergio Stefanni; Domitilia Rosa; Ana Colaco; Ricardo Serrao Santos</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">226</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/49648309"> <span id="translatedtitle">Does sulphide detoxication occur in the gills of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp, Rimicaris exoculata ?</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Ultrastructural observations of the gills of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp Rimicaris exoculata reveal that the epithelial cells contain numerous mitochondria clustered around unusual organelles (diameter of 0.7 to 2.5 ?m) containing membrane stacks. These organelles were termed sulphide-oxidising bodies (SOBs) by structural analogy with organelles observed in the tissues of species adapted to sulphide-rich environments. Moreover, in the gills of R. exoculata,</p> <div class="credits"> <p class="dwt_author">Philippe Compère; Anne-Sophie Martinez; Mireille Charmantier-Daures; Jean-Yves Toullec; Gerhard Goffinet; Françoise Gaill</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">227</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/36736582"> <span id="translatedtitle">Adaptations to hypoxia in <span class="hlt">hydrothermal-vent</span> and cold-seep invertebrates</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The deep sea harbors very unusual environments, such as <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and cold seeps, that illustrate an apparent paradox:\\u000a the environmental conditions are very challenging and yet they display a high biomass when compared to the surrounding environment\\u000a at similar depth. Hypoxia is one of the challenges that these species face to live there. Here, we review specific adaptations\\u000a of</p> <div class="credits"> <p class="dwt_author">Stéphane Hourdez; François H. Lallier</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">228</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.biolbull.org/cgi/reprint/162/1/70.pdf"> <span id="translatedtitle">EFFECTS OF PRESSURE AND TEMPERATURE ON THE EKG AND HEART RATE OF THE <span class="hlt">HYDROTHERMAL</span> <span class="hlt">VENT</span> CRAB BYTHOGRAEA THERMYDRON (BRACHYURA)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Effects of pressure and temperature on the electrocardiogram (EKG) and heart rate of crabs from the Galapagos deep-sea (2500 meters) <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> were studied. <span class="hlt">Vent</span> crabs require high hydrostatic pressure for long term survival. During decompression their EKG is disrupted and their heart rate is reduced. Low tem perature reduces these decompression effects. The crabs have a higher temperature tolerance</p> <div class="credits"> <p class="dwt_author">THOMAS J. MICKEL; JAMES J. CHILDRESS</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">229</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.mbari.org/staff/vrijen/PDFS/Won_2003MEa.pdf"> <span id="translatedtitle">Dispersal barriers and isolation among deep-sea mussel populations (Mytilidae: Bathymodiolus ) from eastern Pacific <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> species are widely dispersed among habitat islands found along the global mid-ocean ridge system. We examine factors that affect population struc- ture, gene flow and isolation in <span class="hlt">vent</span>-endemic mussels of the genus Bathymodiolus from the eastern Pacific Ocean. Mussels were sampled from localities including the Galapagos Rift (GAR, 0 ° ° ° ° 48 ''' ' N;</p> <div class="credits"> <p class="dwt_author">Y. WON; C. R. YOUNG; R. A. LUTZ; R. C. VRIJENHOEK</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">230</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1762412"> <span id="translatedtitle">The Sound Generated by Mid-Ocean Ridge Black Smoker <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> flow through seafloor black smoker <span class="hlt">vents</span> is typically turbulent and vigorous, with speeds often exceeding 1 m/s. Although theory predicts that these flows will generate sound, the prevailing view has been that black smokers are essentially silent. Here we present the first unambiguous field recordings showing that these <span class="hlt">vents</span> radiate significant acoustic energy. The sounds contain a broadband component and narrowband tones which are indicative of resonance. The amplitude of the broadband component shows tidal modulation which is indicative of discharge rate variations related to the mechanics of tidal loading. <span class="hlt">Vent</span> sounds will provide researchers with new ways to study flow through sulfide structures, and may provide some local organisms with behavioral or navigational cues.</p> <div class="credits"> <p class="dwt_author">Crone, Timothy J.; Wilcock, William S.D.; Barclay, Andrew H.; Parsons, Jeffrey D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">231</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/11543277"> <span id="translatedtitle">Metazoans in extreme environments: adaptations of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> and hydrocarbon seep fauna.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Some of the most extreme environments where animals survive are associated with active <span class="hlt">vents</span> and seeps in the deep sea. In addition to the extreme pressure, low temperatures, and lack of light that characterize the deep sea in general, a variety of other factors that are hostile to most animals prevail in these environments. <span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> regions show extremes in temperature, areas of very low oxygen, and the presence of toxic hydrogen sulfide and heavy metals. Hydrocarbon seeps, though much cooler than <span class="hlt">vents</span>, also have regions of very low oxygen and high hydrogen sulfide, as well as other potentially harmful substances such as crude oil and supersaturated brine. Specially adapted animals not only tolerate these conditions, they often thrive under them. In most cases this tolerance is due to a combination of physiological and behavioral adaptations that allow animals to avoid the extremes of their habitats and yet benefit from the chemoautotrophic production characteristic of these environments. PMID:11543277</p> <div class="credits"> <p class="dwt_author">McMullin, E R; Bergquist, D C; Fisher, C R</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">232</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=91466"> <span id="translatedtitle">Identification and Characterization of a Flagellin Gene from the Endosymbiont of the <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Tubeworm Riftia pachyptila</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The bacterial endosymbionts of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> tubeworm Riftia pachyptila play a key role in providing their host with fixed carbon. Results of prior research suggest that the symbionts are selected from an environmental bacterial population, although a free-living form has been neither cultured from nor identified in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> environment. To begin to assess the free-living potential of the symbiont, we cloned and characterized a flagellin gene from a symbiont fosmid library. The symbiont fliC gene has a high degree of homology with other bacterial flagellin genes in the amino- and carboxy-terminal regions, while the central region was found to be nonconserved. A sequence that was homologous to that of a consensus ?28 RNA polymerase recognition <span class="hlt">site</span> lay upstream of the proposed translational start <span class="hlt">site</span>. The symbiont protein was expressed in Escherichia coli, and flagella were observed by electron microscopy. A 30,000-Mr protein subunit was identified in whole-cell extracts by Western blot analysis. These results provide the first direct evidence of a motile free-living stage of a chemoautotrophic symbiont and support the hypothesis that the symbiont of R. pachyptila is acquired with each new host generation.</p> <div class="credits"> <p class="dwt_author">Millikan, Deborah S.; Felbeck, Horst; Stein, Jeffrey L.</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">233</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUSMEP31A..03C"> <span id="translatedtitle">Geothermic Potential Assessment of <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> of Township Barranca De Upia - Meta - Colombia</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> have been traditionally exploited in Colombia as a source of tourism revenue such as pools and saunas. Leaving aside its high potential for geothermal power generation in applications like heating, drying, cooling, extensive use in crops, livestock, electricity generation and more. Currently the use given to this natural resource in the town of Barranca de Upia in Meta department, central Colombia, is like Wellness Centre. However, the geothermal gradient for the area where <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> occur, indicates that the water emerges at temperatures above 70 ° C (Alfaro et al., 2003), which opens a window of opportunity to assess their geothermal potential, in order to know the actual energy potential of the region as an option of augmenting their development. this research is the analysis of information gathered from databases in gravimetry and magnetometry of the study area and the temperatures measured in wells derived from the oil industry. Based on that information, a numerical analysis of the data will be performed in order to establish a model to parameterize the energy potential of the study area and identify possible uses of the energy contained by the <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</p> <div class="credits"> <p class="dwt_author">Chica, J.; Chicangana, G.; Eco Energy Research Group</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">234</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23630523"> <span id="translatedtitle">Biogeography of Persephonella in deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> of the Western Pacific.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields are areas on the seafloor with high biological productivity fueled by microbial chemosynthesis. Members of the Aquificales genus Persephonella are obligately chemosynthetic bacteria, and appear to be key players in carbon, sulfur, and nitrogen cycles in high temperature habitats at deep-sea <span class="hlt">vents</span>. Although this group of bacteria has cosmopolitan distribution in deep-sea <span class="hlt">hydrothermal</span> ecosystem around the world, little is known about their population structure such as intraspecific genomic diversity, distribution pattern, and phenotypic diversity. We developed the multi-locus sequence analysis (MLSA) scheme for their genomic characterization. Sequence variation was determined in five housekeeping genes and one functional gene of 36 Persephonella hydrogeniphila strains originated from the Okinawa Trough and the South Mariana Trough (SNT). Although the strains share >98.7% similarities in 16S rRNA gene sequences, MLSA revealed 35 different sequence types (ST), indicating their extensive genomic diversity. A phylogenetic tree inferred from all concatenated gene sequences revealed the clustering of isolates according to the geographic origin. In addition, the phenotypic clustering pattern inferred from whole-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis can be correlated to their MLSA clustering pattern. This study represents the first MLSA combined with phenotypic analysis indicative of allopatric speciation of deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> bacteria. PMID:23630523</p> <div class="credits"> <p class="dwt_author">Mino, Sayaka; Makita, Hiroko; Toki, Tomohiro; Miyazaki, Junichi; Kato, Shingo; Watanabe, Hiromi; Imachi, Hiroyuki; Watsuji, Tomo-O; Nunoura, Takuro; Kojima, Shigeaki; Sawabe, Tomoo; Takai, Ken; Nakagawa, Satoshi</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">235</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3635849"> <span id="translatedtitle">Biogeography of Persephonella in deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> of the Western Pacific</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields are areas on the seafloor with high biological productivity fueled by microbial chemosynthesis. Members of the Aquificales genus Persephonella are obligately chemosynthetic bacteria, and appear to be key players in carbon, sulfur, and nitrogen cycles in high temperature habitats at deep-sea <span class="hlt">vents</span>. Although this group of bacteria has cosmopolitan distribution in deep-sea <span class="hlt">hydrothermal</span> ecosystem around the world, little is known about their population structure such as intraspecific genomic diversity, distribution pattern, and phenotypic diversity. We developed the multi-locus sequence analysis (MLSA) scheme for their genomic characterization. Sequence variation was determined in five housekeeping genes and one functional gene of 36 Persephonella hydrogeniphila strains originated from the Okinawa Trough and the South Mariana Trough (SNT). Although the strains share >98.7% similarities in 16S rRNA gene sequences, MLSA revealed 35 different sequence types (ST), indicating their extensive genomic diversity. A phylogenetic tree inferred from all concatenated gene sequences revealed the clustering of isolates according to the geographic origin. In addition, the phenotypic clustering pattern inferred from whole-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis can be correlated to their MLSA clustering pattern. This study represents the first MLSA combined with phenotypic analysis indicative of allopatric speciation of deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> bacteria.</p> <div class="credits"> <p class="dwt_author">Mino, Sayaka; Makita, Hiroko; Toki, Tomohiro; Miyazaki, Junichi; Kato, Shingo; Watanabe, Hiromi; Imachi, Hiroyuki; Watsuji, Tomo-o; Nunoura, Takuro; Kojima, Shigeaki; Sawabe, Tomoo; Takai, Ken; Nakagawa, Satoshi</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">236</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008E%26PSL.275...61M"> <span id="translatedtitle">First evidence for high-temperature off-axis <span class="hlt">venting</span> of deep crustal/mantle heat: The Nibelungen <span class="hlt">hydrothermal</span> field, southern Mid-Atlantic Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">During segment-scale studies of the southern Mid-Atlantic Ridge (MAR), 7-12° S, we found evidence in the water column for high-temperature <span class="hlt">hydrothermal</span> activity, off-axis, east of Ascension Island. Extensive water column and seafloor work using both standard CTD and deep submergence AUV and ROV deployments led to the discovery and sampling of the "Drachenschlund" ("Dragon Throat") black smoker <span class="hlt">vent</span> at 8°17.87' S/13°30.45' W in 2915 m water depth. The <span class="hlt">vent</span> is flanked by several inactive chimney structures in a field we have named "Nibelungen". The <span class="hlt">site</span> is located 6 km south of a non-transform offset between two adjacent 2nd-order ridge-segments and 9 km east of the presently-active, northward-propagating A2 ridge-segment, on a prominent outward-facing fault scarp. Both <span class="hlt">vent</span>-fluid compositions and host-rock analyses show this <span class="hlt">site</span> to be an ultramafic-hosted system, the first of its kind to be found on the southern MAR. The thermal output of this single <span class="hlt">vent</span>, based on plume rise-height information, is estimated to be 60 ± 15 MW. This value is high for a single "black smoker" <span class="hlt">vent</span> but small for an entire field. The tectonic setting and low He content of the <span class="hlt">vent</span> fluids imply that high-temperature off-axis <span class="hlt">venting</span> at "Drachenschlund" is driven not by magmatic processes, as at the majority of on-axis <span class="hlt">hydrothermal</span> systems, but by residual heat "mined" from the deeper lithosphere. Whether this heat is being extracted from high-temperature mantle peridotites or deep crustal cumulates formed at the "duelling" non-transfrom offset is unclear, in either case the Drachenschlund <span class="hlt">vent</span> provides the first direct observations of how cooling of deeper parts of the lithosphere, at least at slow-spreading ridges, may be occurring.</p> <div class="credits"> <p class="dwt_author">Melchert, B.; Devey, C. W.; German, C. R.; Lackschewitz, K. S.; Seifert, R.; Walter, M.; Mertens, C.; Yoerger, D. R.; Baker, E. T.; Paulick, H.; Nakamura, K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-10-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">237</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/16345831"> <span id="translatedtitle">Chemolithotrophic sulfur-oxidizing bacteria from the galapagos rift <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Three distinct physiological types of sulfur-oxidizing bacteria were enriched and isolated from samples collected at several deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> (2,550 m) of the Galapagos Rift ocean floor spreading center. Twelve strains of the obligately chemolithotrophic genus Thiomicrospira were obtained from <span class="hlt">venting</span> water and from microbial mats covering surfaces in the immediate vicinity of the <span class="hlt">vents</span>. From these and other sources two types of obligately heterotrophic sulfur oxidizers were repeatedly isolated that presumably oxidized thiosulfate either to sulfate (acid producing; 9 strains) or to polythionates (base producing; 74 strains). The former were thiobacilli-like, exhibiting a thiosulfate-stimulated increase in growth and CO(2) incorporation, whereas the latter were similar to previously encountered pseudomonad-like heterotrophs. The presence of chemolithotrophic sulfur-oxidizing bacteria in the sulfide-containing <span class="hlt">hydrothermal</span> water supports the hypothesis that chemosynthesis provides a substantial primary food source for the rich populations of invertebrates found in the immediate vicinity of the <span class="hlt">vents</span>. PMID:16345831</p> <div class="credits"> <p class="dwt_author">Ruby, E G; Wirsen, C O; Jannasch, H W</p> <p class="dwt_publisher"></p> <p class="publishDate">1981-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">238</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=244008"> <span id="translatedtitle">Chemolithotrophic Sulfur-Oxidizing Bacteria from the Galapagos Rift <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> †</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Three distinct physiological types of sulfur-oxidizing bacteria were enriched and isolated from samples collected at several deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> (2,550 m) of the Galapagos Rift ocean floor spreading center. Twelve strains of the obligately chemolithotrophic genus Thiomicrospira were obtained from <span class="hlt">venting</span> water and from microbial mats covering surfaces in the immediate vicinity of the <span class="hlt">vents</span>. From these and other sources two types of obligately heterotrophic sulfur oxidizers were repeatedly isolated that presumably oxidized thiosulfate either to sulfate (acid producing; 9 strains) or to polythionates (base producing; 74 strains). The former were thiobacilli-like, exhibiting a thiosulfate-stimulated increase in growth and CO2 incorporation, whereas the latter were similar to previously encountered pseudomonad-like heterotrophs. The presence of chemolithotrophic sulfur-oxidizing bacteria in the sulfide-containing <span class="hlt">hydrothermal</span> water supports the hypothesis that chemosynthesis provides a substantial primary food source for the rich populations of invertebrates found in the immediate vicinity of the <span class="hlt">vents</span>. Images</p> <div class="credits"> <p class="dwt_author">Ruby, E. G.; Wirsen, C. O.; Jannasch, H. W.</p> <p class="dwt_publisher"></p> <p class="publishDate">1981-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">239</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFM.B42C..07L"> <span id="translatedtitle">Quantifying metabolic rates in submarine <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> chimneys: A reaction transport model</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The fluids emanating from active submarine <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> chimneys provide a window into subseafloor processes and, through mixing with seawater, are responsible for steep thermal and compositional gradients that provide the energetic basis for diverse biological communities. Although several models have been developed to better understand the dynamic interplay of seawater, <span class="hlt">hydrothermal</span> fluid, minerals and microorganisms inside chimney walls, none provide a fully integrated approach to quantifying the biogeochemistry of these <span class="hlt">hydrothermal</span> systems. In an effort to remedy this, a fully coupled biogeochemical reaction transport model of a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> chimney has been developed that explicitly quantifies the rate of microbial catalysis while taking into account geochemical processes such as fluid flow, solute transport and oxidation-reduction reactions associated with fluid mixing as a function of temperature. Methanogenesis, hydrogen oxidation by oxygen and sulfate, sulfide oxidation by oxygen and methane oxidation by oxygen and sulfate are the metabolisms included in the reaction network. Model results indicate that microbial catalysis is fastest in the hottest habitable portion of the <span class="hlt">vent</span> chimney except for methane oxidation by oxygen, which peaks near the seawater-side of the chimney at 20 nmol /cm^3 yr. The dominant metabolisms in the chimney are hydrogen oxidation by sulfate and oxygen and sulfide oxidation at peak rates 3200 , 300 and 900 nmol /cm^3 yr, respectively. The maximum rate of hydrogenotrophic methanogensis is just under 0.07 nmol /cm^3 yr, the slowest of the metabolisms considered. Due to thermodynamic inhibition, there is no anaerobic oxidation of methane by sulfate (AOM). The model developed here provides a quantitative approach to understanding the rates of biogeochemical transformations in <span class="hlt">hydrothermal</span> systems and can be used to better understand the role of microbial activity in the deep subsurface.</p> <div class="credits"> <p class="dwt_author">LaRowe, D.; Dale, A.; Aguilera, D.; Amend, J. P.; Regnier, P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">240</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3218092"> <span id="translatedtitle">Conjugating effects of symbionts and environmental factors on gene expression in deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussels</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Background The deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus harbors thiotrophic and methanotrophic symbiotic bacteria in its gills. While the symbiotic relationship between this <span class="hlt">hydrothermal</span> mussel and these chemoautotrophic bacteria has been described, the molecular processes involved in the cross-talking between symbionts and host, in the maintenance of the symbiois, in the influence of environmental parameters on gene expression, and in transcriptome variation across individuals remain poorly understood. In an attempt to understand how, and to what extent, this double symbiosis affects host gene expression, we used a transcriptomic approach to identify genes potentially regulated by symbiont characteristics, environmental conditions or both. This study was done on mussels from two contrasting populations. Results Subtractive libraries allowed the identification of about 1000 genes putatively regulated by symbiosis and/or environmental factors. Microarray analysis showed that 120 genes (3.5% of all genes) were differentially expressed between the Menez Gwen (MG) and Rainbow (Rb) <span class="hlt">vent</span> fields. The total number of regulated genes in mussels harboring a high versus a low symbiont content did not differ significantly. With regard to the impact of symbiont content, only 1% of all genes were regulated by thiotrophic (SOX) and methanotrophic (MOX) bacteria content in MG mussels whereas 5.6% were regulated in mussels collected at Rb. MOX symbionts also impacted a higher proportion of genes than SOX in both <span class="hlt">vent</span> fields. When host transcriptome expression was analyzed with respect to symbiont gene expression, it was related to symbiont quantity in each field. Conclusions Our study has produced a preliminary description of a transcriptomic response in a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel host of both thiotrophic and methanotrophic symbiotic bacteria. This model can help to identify genes involved in the maintenance of symbiosis or regulated by environmental parameters. Our results provide evidence of symbiont effect on transcriptome regulation, with differences related to type of symbiont, even though the relative percentage of genes involved remains limited. Differences observed between the <span class="hlt">vent</span> <span class="hlt">site</span> indicate that environment strongly influences transcriptome regulation and impacts both activity and relative abundance of each symbiont. Among all these genes, those participating in recognition, the immune system, oxidative stress, and energy metabolism constitute new promising targets for extended studies on symbiosis and the effect of environmental parameters on the symbiotic relationships in B. azoricus.</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_11");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" 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onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a style="font-weight: bold;">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_14");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">241</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2001DSRI...48.1325D"> <span id="translatedtitle">Variations in deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> communities on the Mid-Atlantic Ridge near the Azores plateau</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Near the Azores Triple Junction as the Azores Plateau is approached, the ridge axis becomes shallower; its depth decreases from ca. 2400 m in the R AINBOW <span class="hlt">vent</span> field (36°13'N) to ca. 850 m in the M ENEZ G WEN <span class="hlt">vent</span> field (37°35'N). In this area, extensive mussel beds of the mytilid Bathymodiolus azoricus dominate the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fauna, along with populations of three shrimps ( Rimicaris exoculata, Mirocaris fortunata and Chorocaris chacei). The main physical and chemical characteristics of the <span class="hlt">vent</span> habitat were studied by discrete sampling, in situ analysis and sediment trap moorings. The <span class="hlt">vent</span> fauna is distributed along a variable band where the <span class="hlt">vent</span> fluids and seawater mix, with R. exoculata living in the most concentrated areas and Bathymodiolus azoricus in the most diluted zones. Various non-endemic species live at the border of the <span class="hlt">vent</span> field. The variations observed in structure and composition of the communities along the depth gradient are most likely due to changes in <span class="hlt">vent</span> fluid toxicity (metallic and sulphide content) and suspended mineral particles, which render the fluids harsher for species living there. The main faunal differences observed between L UCKY S TRIKE and M ENEZ G WEN <span class="hlt">hydrothermal</span> fields are due to an impoverishment in the <span class="hlt">hydrothermal</span> endemic species and to the penetration of bathyal species. The comparison of the three studied <span class="hlt">vent</span> fields suggests the existence of a succession of several biogeographic islands rather than a single province.</p> <div class="credits"> <p class="dwt_author">Desbruyères, D.; Biscoito, M.; Caprais, J.-C.; Colaço, A.; Comtet, T.; Crassous, P.; Fouquet, Y.; Khripounoff, A.; Le Bris, N.; Olu, K.; Riso, R.; Sarradin, P.-M.; Segonzac, M.; Vangriesheim, A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">242</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24080408"> <span id="translatedtitle">Proteomic responses to metal-induced oxidative stress in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span>-living mussels, Bathymodiolus sp., on the Southwest Indian Ridge.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Bathymodiolin mussels are amongst the dominant fauna occupying <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystems throughout the World's oceans. This subfamily inhabits a highly ephemeral and variable environment, where exceptionally high concentrations of reduced sulphur species and heavy metals necessitate adaptation of specialised detoxification mechanisms. Whilst cellular responses to common anthropogenic pollutants are well-studied in shallow-water species, they remain limited in deep-sea <span class="hlt">vent</span> fauna. Bathymodiolus sp. were sampled from two newly-discovered <span class="hlt">vent</span> <span class="hlt">sites</span> on the Southwest Indian Ridge (Tiamat and Knuckers Gaff) by the remotely operated vehicle (ROV) Kiel 6000 during the RRS James Cook cruise, JC 067 in November 2011. Here, we use redox proteomics to investigate the effects of tissue metal accumulation on protein expression and thiol oxidation in gill. Following 2D PAGE, we demonstrate a significant difference in intensity in 30 protein spots in this organ between the two <span class="hlt">vent</span> <span class="hlt">sites</span> out of 205 matched spots. We also see significant variations in thiol oxidation in 15 spots, out of 143 matched. At Tiamat, 23 protein spots are up-regulated compared to Knuckers Gaff and we identify 5 of these with important roles in metabolism, cell structure, stress response, and redox homeostasis. We suggest that increased metal exposure triggers changes in the proteome, regulating tissue uptake. This is evident both between <span class="hlt">vent</span> <span class="hlt">sites</span> and across a chemical gradient within the Knuckers Gaff <span class="hlt">vent</span> <span class="hlt">site</span>. Our findings highlight the importance of proteomic plasticity in successful adaptation to the spatially and temporally fluctuating chemical environments that are characteristic of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> habitats. PMID:24080408</p> <div class="credits"> <p class="dwt_author">Cole, Catherine; Coelho, Ana Varela; James, Rachael H; Connelly, Doug; Sheehan, David</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">243</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1990JGR....9512947A"> <span id="translatedtitle">Geological and <span class="hlt">hydrothermal</span> controls on the distribution of megafauna in Ashes <span class="hlt">Vent</span> Field, Juan de Fuca Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A computerized data base was constructed to aid in the interpretation of biological and geological observations recorded from 7662 photographs taken of Ashes <span class="hlt">vent</span> field (located along the SW wall of the summit caldera of Axial Volcano, Juan de Fuca Ridge) during 1985-1986 using the Pisces IV submersible and a towed camera system. The transition region between the locus of high-temperature <span class="hlt">vents</span> in Ashes <span class="hlt">vent</span> field (i.e., Inferno, 326°C; Hell, 301°C; and Virgin Mound, 298°C) and more typical environmental conditions for the summit caldera of Axial Volcano as a whole is zoned spatially with respect to sediment type and organism assemblage. Three general ecological zones are identified within the <span class="hlt">vent</span> field: (1) the central <span class="hlt">vent</span> zone (within 100 m of a high-temperature <span class="hlt">vent</span>), dominated by <span class="hlt">vent</span>-associated organisms (vestimentiferan tube worms, clams, bacterial mats) and sedimentation (high-temperature, plume-derived and low-temperature, in situ deposits); (2) the distal <span class="hlt">vent</span> zone (100-725 m from any high-temperature <span class="hlt">vent</span>), characterized by extensive fields of iron oxide, iron silicate and silica chimneys and sediment (nontronite assemblage material), as well as maximum densities of most nonvent fauna; and (3) the nonvent impact zone (725-1300 m), indicated by elevated densities of nonvent organisms relative to regional (i.e., caldera-wide) values and maximum Bathydorus sp. sponge densities. The distribution of vestimentiferan tube worms is limited to within 90 m of known high-temperature <span class="hlt">venting</span> (central <span class="hlt">vent</span> zone); and anemones were observed only between 30 and 40 m from hot <span class="hlt">vents</span>. Clams and microbial mats are concentrated in the central <span class="hlt">vent</span> zone, as well, but occur sporadically up to 1250 m from the hot <span class="hlt">vents</span> in association with <span class="hlt">hydrothermal</span> nontronite that is probably precipitating in situ from <60°C <span class="hlt">vent</span> fluid; thus megafaunal distributions are a useful indicator of poorly defined, often diffuse low-temperature <span class="hlt">hydrothermal</span> activity on the seafloor. Maximum densities of nonvent echinoderms (i.e., holothurians, sea stars, urchins) are associated with the distal <span class="hlt">venting</span> zone. Distributions of megafauna not endemic to the <span class="hlt">vent</span> environment are sensitive to both local geology (particularly the nature of the substrate) and effects of <span class="hlt">hydrothermal</span> activity such as enhanced food availability or <span class="hlt">hydrothermal</span> sedimentation. Although evidence for active <span class="hlt">venting</span> is not apparent in the nonvent impact zone, photographic data suggest that the type and number of megafauna living in this region are significantly influenced by proximity to low- and high-temperature <span class="hlt">hydrothermal</span> sources that support enhanced microbial production and produce sediment of <span class="hlt">hydrothermal</span> origin, which may be advected to the peripheral environment. Statistical interpretation of photographic data suggests an outer limit to the extent of <span class="hlt">vent</span> influence on benthic megafauna (i.e., Bathydorus sp. sponges) of about 1000-1300 m for the <span class="hlt">hydrothermal</span> system active at Ashes <span class="hlt">vent</span> field in 1985-1986. On the scale of a single <span class="hlt">vent</span> field, <span class="hlt">hydrothermal</span> activity apparently results in a less patchy distribution of benthic, nonvent organisms within the central and distal <span class="hlt">vent</span> zones than is common in the nonvent environment.</p> <div class="credits"> <p class="dwt_author">Arquit, Anne M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1990-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">244</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41134215"> <span id="translatedtitle">Heat, volume and chemical fluxes from submarine <span class="hlt">venting</span>: A synthesis of results from the Rainbow <span class="hlt">hydrothermal</span> field, 36°N MAR</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">High-temperature <span class="hlt">hydrothermal</span> activity occurs in all ocean basins and along ridge crests of all spreading rates. While it has long been recognized that the fluxes associated with such <span class="hlt">venting</span> are large, precise quantification of their impact on ocean biogeochemistry has proved elusive. Here, we report a comprehensive study of heat, fluid and chemical fluxes from a single submarine <span class="hlt">hydrothermal</span> field.</p> <div class="credits"> <p class="dwt_author">C. R. German; A. M. Thurnherr; J. Knoery; J.-L. Charlou; P. Jean-Baptiste; H. N. Edmonds</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">245</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/61433817"> <span id="translatedtitle">Out of the deep-sea into a land-based aquarium environment: Investigating innate immunity in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> are considered as some of the most adverse\\u000a environments in the world, yet the animals dwelling around the <span class="hlt">vent</span>\\u000a <span class="hlt">sites</span> exhibit high productivity and therefore must cope with unusual\\u000a levels of heavy metals, pH, temperature, CO(2) and sulfide, in addition\\u000a to environmental microbes. In an attempt to understand the physiological\\u000a reactions of animals normally set to endure</p> <div class="credits"> <p class="dwt_author">Raul Bettencourt; Valentina Costa; Mario Laranjo; Domitilia Rosa; Luis Pires; Ana Colaco; Pierre Marie Sarradin; Humberto Lopes; Marie Josee Sarrazin; Ricardo Serrao Santos</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">246</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/43375497"> <span id="translatedtitle">Out of the deep sea into a land-based aquarium environment: investigating physiological adaptations in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> are considered to be some of the most\\u000a extreme environments in the world, yet the animals dwelling around the\\u000a <span class="hlt">vent</span> <span class="hlt">sites</span> exhibit high productivity and must therefore deal with\\u000a unusual levels of heavy metals, pH, temperature, CO2, and sulphides, in\\u000a addition to environmental microbes. In an attempt to understand the\\u000a physiological reactions of animals able to endure</p> <div class="credits"> <p class="dwt_author">Raul Bettencourt; Valentina Costa; Mario Laranjo; Domitilia Rosa; Luis Pires; Ana Colaco; Humberto Lopes; Ricardo Serrao Santos</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">247</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2396607"> <span id="translatedtitle">Formation of Zn- and Fe-sulfides near <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> at the Eastern Lau Spreading Center: implications for sulfide bioavailability to chemoautotrophs</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Background The speciation of dissolved sulfide in the water immediately surrounding deep-ocean <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> is critical to chemoautotrophic organisms that are the primary producers of these ecosystems. The objective of this research was to identify the role of Zn and Fe for controlling the speciation of sulfide in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields at the Eastern Lau Spreading Center (ELSC) in the southern Pacific Ocean. Compared to other well-studied <span class="hlt">hydrothermal</span> systems in the Pacific, the ELSC is notable for unique ridge characteristics and gradients over short distances along the north-south ridge axis. Results In June 2005, diffuse-flow (< 50°C) and high-temperature (> 250°C) <span class="hlt">vent</span> fluids were collected from four field <span class="hlt">sites</span> along the ELSC ridge axis. Total and filtered Zn and Fe concentrations were quantified in the <span class="hlt">vent</span> fluid samples using voltammetric and spectrometric analyses. The results indicated north-to-south variability in <span class="hlt">vent</span> fluid composition. In the high temperature <span class="hlt">vent</span> fluids, the ratio of total Fe to total Zn varied from 39 at Kilo Moana, the most northern <span class="hlt">site</span>, to less than 7 at the other three <span class="hlt">sites</span>. The concentrations of total Zn, Fe, and acid-volatile sulfide indicated that oversaturation and precipitation of sphalerite (ZnS(s)) and pyrite (FeS2(s)) were possible during cooling of the <span class="hlt">vent</span> fluids as they mixed with the surrounding seawater. In contrast, most samples were undersaturated with respect to mackinawite (FeS(s)). The reactivity of Zn(II) in the filtered samples was tested by adding Cu(II) to the samples to induce metal-exchange reactions. In a portion of the samples, the concentration of labile Zn2+ increased after the addition of Cu(II), indicating the presence of strongly-bound Zn(II) species such as ZnS clusters and nanoparticles. Conclusion Results of this study suggest that Zn is important to sulfide speciation at ELSC <span class="hlt">vent</span> habitats, particularly at the southern <span class="hlt">sites</span> where Zn concentrations increase relative to Fe. As the <span class="hlt">hydrothermal</span> fluids mix with the ambient seawater, Zn-sulfide clusters and nanoparticles are likely preventing sulfide oxidation by O2 and reducing bioavailability of S(-II) to organisms.</p> <div class="credits"> <p class="dwt_author">Hsu-Kim, Heileen; Mullaugh, Katherine M; Tsang, Jeffrey J; Yucel, Mustafa; Luther, George W</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">248</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/15060286"> <span id="translatedtitle">Hydrocarbons in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fluids: the role of chromium-bearing catalysts.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Fischer-Tropsch type (FTT) synthesis has long been proposed to account for the existence of hydrocarbons in <span class="hlt">hydrothermal</span> fluids. We show that iron- and chromium-bearing minerals catalyze the abiotic formation of hydrocarbons. In addition to production of methane (CH4aq), we report abiotic generation of ethane (C2H6aq) and propane (C3H8aq) by mineral-catalyzed <span class="hlt">hydrothermal</span> reactions at 390 degrees C and 400 bars. Results suggest that the chromium component in ultramafic rocks could be an important factor for FTT synthesis during water-rock interaction in mid-ocean ridge <span class="hlt">hydrothermal</span> systems. This in turn could help to support microbial communities now recognized in the subsurface at deep-sea <span class="hlt">vents</span>. PMID:15060286</p> <div class="credits"> <p class="dwt_author">Foustoukos, Dionysis I; Seyfried, William E</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-05-14</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">249</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFMOS13A1696Y"> <span id="translatedtitle">Structural and functional diversity of microbial communities beneath the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> at the Iheya North field of the Mid-Okinawa Trough (IODP Expedition 331)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Complex and diverse microbial communities in deep-sea <span class="hlt">hydrothermal</span> fluids are apparently different from those in ambient seawater, some of which are predicted to migrate along <span class="hlt">hydrothermal</span> vein from "subvent biosphere". Subseafloor environment just beneath active <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> has been expected to be one of the most conceivable habitats for metabolically active and diverse microbial community. We conducted the scientific ocean drilling (IODP Expedition 331) for the Iheya North <span class="hlt">hydrothermal</span> field in the Mid-Okinawa Trough in Sept. 2010, and collected core samples from the subseafloor biosphere beneath the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span>. IODP <span class="hlt">Site</span> C0014 was located 450 m east off the main <span class="hlt">hydrothermal</span> <span class="hlt">vent</span>. Temperature exceeded the limit of life at the depth of approximately 40 m below the seafloor. Both microscopy and quantitative PCR analyses successfully detected microbial populations in the shallower zone above 15 mbsf. However, the cultivation attempts of (hyper-)thermophiles were unsuccessful all over the depth. Culture-independent molecular biological experiments showed that microbial community composition distinctly changed with depth, possibly because of physicochemical conditions such as methane, sulfate and temperature. Microbial activities of methanogenesis and anaerobic methane oxidation were in accordance with the geochemical profiles of methane and sulfate. These results indicated the presence of functionally active subseafloor microbial communities but those were different from expected members in subvent biosphere. <span class="hlt">Site</span> C0017 located 1.6 km east off the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> is a potential seawater recharge zone of the <span class="hlt">hydrothermal</span> system, where seawater penetrates into the oceanic crust. The lithostratigraphy consists of characteristic coarse angular pumiceous gravel, lying above and below hemipelagic mud, in which high permeability may allow entrainment of seawater. As is the case with sedimentary subsurface environments, uncultivated archaeal groups were dominantly detected in the hemipelagic sediment above and below pumice layer. In contrast, the ammonia-oxidizing archaea (Nitrosopumilales) were outstandingly dominant at pumice layer of around 20 mbsf, possibly related to oxidative seawater transport. At the deeper layer of around 150 mbsf, where high temperature over 90°C was recorded, microbial community structure was similar to that in high temperature zone of <span class="hlt">Site</span> C0014. Our data suggest that the temperature gradient formed by <span class="hlt">hydrothermal</span> activity is one of the important factors controlling changes in subseafloor microbial communities.</p> <div class="credits"> <p class="dwt_author">Yanagawa, K.; Nunoura, T.; Kawagucci, S.; Hirai, M.; Sunamura, M.; Breuker, A.; Brandt, L.; House, C. H.; McAllister, S. M.; Moyer, C. L.; Takai, K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">250</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23741175"> <span id="translatedtitle">Arsenic speciation in food chains from mid-Atlantic <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Arsenic concentration and speciation were determined in benthic fauna collected from the Mid-Atlantic Ridge <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. The shrimp species, Rimicaris exoculata, the <span class="hlt">vent</span> chimney-dwelling mussel, Bathymodiolus azoricus, Branchipolynoe seepensis, a commensal worm of B. azoricus, and the gastropod Peltospira smaragdina showed variations in As concentration and in stable isotope (?(13)C and ?(15)N) signature between species, suggesting different sources of As uptake. Arsenic speciation showed arsenobetaine to be the dominant species in R. exoculata, whereas in B. azoricus and B. seepensis arsenosugars were most abundant, although arsenobetaine, dimethylarsinate, and inorganic arsenic were also observed, along with several unidentified species. Scrape samples from outside the <span class="hlt">vent</span> chimneys, covered with microbial mat, which is a presumed food source for many <span class="hlt">vent</span> organisms, contained high levels of total As, but organic species were not detectable. The formation of arsenosugars in pelagic environments is typically attributed to marine algae, and the pathway to arsenobetaine is still unknown. The occurrence of arsenosugars and arsenobetaine in these deep sea organisms, where primary production is chemolithoautotrophic and stable isotope analyses indicate food sources are of <span class="hlt">vent</span> origin, suggests that organic arsenicals can occur in a food web without algae or other photosynthetic life. PMID:23741175</p> <div class="credits"> <p class="dwt_author">Taylor, Vivien F; Jackson, Brian P; Siegfried, Matthew; Navratilova, Jana; Francesconi, Kevin A; Kirshtein, Julie; Voytek, Mary</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">251</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003EAEJA.....2858T"> <span id="translatedtitle">High-Resolution Magnetic Field and Bathymetric Imaging of <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Areas using Autonomous Underwater Vehicles, Remotely Operated Vehicles and Submersibles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">High-resolution, near-bottom bathymetric and magnetic field surveys have been carried out over <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> areas using the autonomous underwater vehicle ABE, the ROV Jason and ALVIN. Bathymetry is measured using a 675 kHz, scanning pencil-beam altimeter and, most recently, a 200 kHz swath mapping sonar. Vehicle depth is obtained by pressure sensor and vector magnetic field is measured using either a 3-axis fluxgate or, most recently, a digital magneto-resistor sensor. Typical survey altitude ranges from 20 m (Jason, ALVIN) to 40-60 m (ABE), with line spacing ranging from 20 to 40-60 m respectively. This survey geometry provides sufficient resolution for the detection of magnetic anomalies associated with geological features, most notably <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. We present detailed surveys over 5 <span class="hlt">hydrothermal</span> <span class="hlt">sites</span> found at mid-ocean ridges that range from fast to slow spreading. The TAG <span class="hlt">hydrothermal</span> area, on the slow spreading Mid-Atlantic Ridge, was imaged using ALVIN in 1993 and has a magnetic low directly beneath the active chimney complex. On the intermediate-rate Endeavour segment of the Juan de Fuca Ridge (JDF), we imaged individual chimneys of Main Endeavour Field (MEF) and found that they are associated with discrete magnetic lows. On Explorer Ridge, ABE mapping in 2002 revealed that the Magic Mountain <span class="hlt">hydrothermal</span> area is also associated with a region of low magnetization. In 2002, at the intermediate-rate Galapagos Rift at 86W, ABE mapped the original "Rose Garden" <span class="hlt">hydrothermal</span> area, which has now become inactive. This <span class="hlt">site</span> has a magnetic low associated with it while only 200 m NW of this <span class="hlt">site</span>, an area of recent low-T <span class="hlt">hydrothermal</span> activity (i.e. Rosebud <span class="hlt">site</span>) does not produce a magnetic response. A 2001 ABE bathymetric and magnetic survey at the EPR crest at 9 50N shows weak magnetic anomaly lows associated with active high-T <span class="hlt">venting</span> in the axial trough. The observed magnetic anomalies share a number of common features, most notably a circular plan view geometry (typical diameter ˜100m) that indicates a discrete and highly localized anomalous magnetization source (i.e. an up-flow pipe geometry). Magnetic lows are found at both active and inactive (or relict) <span class="hlt">vent</span> <span class="hlt">sites</span> indicating that crustal alteration of the extrusive basalt rather than thermal demagnetization is the likely cause for low magnetization. Near-bottom magnetic and bathymetric surveys can be successful in locating zones of active and inactive <span class="hlt">hydrothermal</span> activity.</p> <div class="credits"> <p class="dwt_author">Tivey, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">252</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004AGUFM.V41B1393K"> <span id="translatedtitle">Characterization of Dissolved Organic Matter from Deep-sea Floor <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> in South Mariana Backarc Spreading Center</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In South Mariana Backarc Spreading Center, a few active <span class="hlt">hydrothermal</span> fields are located. We investigated a characterization of dissolved organic matter (DOM) from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in this area, in order to clarify the biosphere beneath deep-sea floor. Hot water sample was collected from a drilled hole (APM01 located in Fryer <span class="hlt">site</span>, 12o 55.22fN, 143o 37.16fE, depth 2850m) during the ROPOS/TN167A cruise in March 2004. The hole had been drilled during Hakurei-Maru 2 cruise in January 2004. Another hot water sample was collected from a natural black smoker located in Pika <span class="hlt">site</span> (12o 55.15fN, 143o 36.96fE, depth 2773m) during YK03-09 cruise. In this investigation, we developed a standalone filtration system in order to collect and enrich dissolved organic matter of quite low concentration. This system was designed to be put near <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> for at least 24h. This system has an ODS disk (EmporeTM High Performance Extraction Disk C18 90mm?) with a pre-filter (Whatman GMF 1 ?)m filter paper) to adsorb dilute organics. We collected DOM from the APM01 casing pipe for about 30h (Tmax = 25-30 o C, the estimated volume of filtrated water is max. 300L) using this filtration system. Adsorbed organics were eluted with methanol for 12h twice and toluene once using soxhlet extractor. Recovered amounts of methanol eluents are 72.8mg for APM01, and 89.7mg for the black smoker. Prior to GCMS analysis, we carried out high resolution 1 H-NMR measurement (400MHz), together with the DOM samples collected from the Suiyo Seamount in July-August 2001 and August 2002. Most of the samples show signals in the region of 3-4 ppm, and the samples from the <span class="hlt">vents</span> of relatively low temperatures (APM01 and AP04: the natural <span class="hlt">vent</span> at the Suiyo Seamount, temperature 8-48o C ) show signals also in the region of 0.8-1.6 ppm.</p> <div class="credits"> <p class="dwt_author">Kitajima, F.; Yamanaka, T.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">253</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2006E%26PSL.245..202C"> <span id="translatedtitle">Evidence for <span class="hlt">hydrothermal</span> <span class="hlt">venting</span> in Fe isotope compositions of the deep Pacific Ocean through time</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Temporal variations in Fe isotope compositions at three locations in the Pacific Ocean over the last 10 Ma are inferred from high-resolution analyses of three hydrogenetic ferromanganese crusts. Iron pathways to the central deep Pacific Ocean appear to have remained constant over the past 10 Ma, reflected by a remarkably constant Fe isotope composition, despite large changes in the Fe delivery rates to the surface ocean via dust. These results suggest that the Fe cycle in the deep ocean is decoupled from that in surface waters. By contrast, one ferromanganese crust from the Izu-Bonin (IB) back-arc/marginal basin of the W. Pacific exhibits large ? 56Fe variations. In that crust, decreases in ? 56Fe values correlate with increases in Mn, Mg, Ni, Cu, Zn, Mo, and V contents, and consistent with periods of intense <span class="hlt">hydrothermal</span> input and increased growth rates. A second crust located within 100 km of the first IB sample does not record any of these periods of enhanced <span class="hlt">hydrothermal</span> input. This probably reflects the isolated pathways by which <span class="hlt">hydrothermally</span> sourced Fe may have migrated in the back arc, highlighting the high degree of provinciality that Fe isotopes may have in the modern (oxic) oceans. Our results demonstrate that despite efficient removal at the source, <span class="hlt">hydrothermal</span> Fe injected into the deep ocean could account for a significant fraction of the dissolved Fe pool in the deep ocean, and that <span class="hlt">hydrothermally</span> sourced Fe fluxes to the open ocean may have lower ? 56Fe values than those measured so far in situ at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. Correlation between ? 56Fe values and elements enriched in <span class="hlt">hydrothermal</span> fluids may provide a means for distinguishing <span class="hlt">hydrothermal</span> Fe from other low-? 56Fe sources to the oceans such as dissolved riverine Fe or porewaters in continental shelf sediments.</p> <div class="credits"> <p class="dwt_author">Chu, N.-C.; Johnson, C. M.; Beard, B. L.; German, C. R.; Nesbitt, R. W.; Frank, M.; Bohn, Marcel; Kubik, P. W.; Usui, A.; Graham, I.</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">254</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=182849"> <span id="translatedtitle">DNA-DNA Solution Hybridization Studies of the Bacterial Symbionts of <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Tube Worms (Riftia pachyptila and Tevnia jerichonana)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The giant tube worm, Riftia pachyptila (phylum Vestimentifera), is known only from four widely separated sulfide-rich deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> systems. This invertebrate is nourished by intracellular, chemoautotrophic bacterial symbionts which reside in a specialized trophosome tissue. The symbiont has not been cultured independently and is believed to be acquired de novo by host larvae of each generation. In the current study, R. pachyptila symbiont DNA was purified from the two most distant <span class="hlt">sites</span> on the basis of its difference in density versus host DNA. These two standards were hybridized against trophosome DNAs of 13 individuals from the Guaymas Basin, Galapagos Rift, and 13°N <span class="hlt">vents</span>. This indicated that all R. pachyptila symbionts are conspecific and that the variability in DNA-DNA hybridization (relative binding ratio [RBR]) was comparable within or between widely separated <span class="hlt">vents</span>. The symbiont of another tube worm, Tevnia jerichonana, was found to be the same as that of R. pachyptila, the first case in which distinct hosts possess the same sulfur bacterial symbiont. By contrast, Lamellibrachia sp. (same class as T. jerichonana) showed insignificant RBR with the R. pachyptila symbiont. DNA derived from solely eucaryotic tissue of R. pachyptila showed a surprisingly high RBR (20 to 50) with density-separated DNA standards. With DNAs obtained from physically separated symbionts, independent solution hybridization experiments confirmed the above-described conclusions. Possible explanations for this host-symbiont homology are discussed.</p> <div class="credits"> <p class="dwt_author">Edwards, Deeanne B.; Nelson, Douglas C.</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">255</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/16348457"> <span id="translatedtitle">DNA-DNA Solution Hybridization Studies of the Bacterial Symbionts of <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Tube Worms (Riftia pachyptila and Tevnia jerichonana).</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The giant tube worm, Riftia pachyptila (phylum Vestimentifera), is known only from four widely separated sulfide-rich deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> systems. This invertebrate is nourished by intracellular, chemoautotrophic bacterial symbionts which reside in a specialized trophosome tissue. The symbiont has not been cultured independently and is believed to be acquired de novo by host larvae of each generation. In the current study, R. pachyptila symbiont DNA was purified from the two most distant <span class="hlt">sites</span> on the basis of its difference in density versus host DNA. These two standards were hybridized against trophosome DNAs of 13 individuals from the Guaymas Basin, Galapagos Rift, and 13 degrees N <span class="hlt">vents</span>. This indicated that all R. pachyptila symbionts are conspecific and that the variability in DNA-DNA hybridization (relative binding ratio [RBR]) was comparable within or between widely separated <span class="hlt">vents</span>. The symbiont of another tube worm, Tevnia jerichonana, was found to be the same as that of R. pachyptila, the first case in which distinct hosts possess the same sulfur bacterial symbiont. By contrast, Lamellibrachia sp. (same class as T. jerichonana) showed insignificant RBR with the R. pachyptila symbiont. DNA derived from solely eucaryotic tissue of R. pachyptila showed a surprisingly high RBR (20 to 50) with density-separated DNA standards. With DNAs obtained from physically separated symbionts, independent solution hybridization experiments confirmed the above-described conclusions. Possible explanations for this host-symbiont homology are discussed. PMID:16348457</p> <div class="credits"> <p class="dwt_author">Edwards, D B; Nelson, D C</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">256</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFMOS13B1731M"> <span id="translatedtitle">How Disturbance Influences Community Composition at <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span>: a Theoretical Model of Macrofaunal Coexistence</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Biological communities at spreading centers experience a continuum of disturbance regimes, with fast spreading ridges characterized by relatively frequent tectonic and magmatic events, and slow spreading ridges displaying more stable environmental conditions. We develop a theoretical model to show how disturbance (or lack thereof) can influence the composition of biological communities at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. Our model assumptions are based on empirical data, which show that macrofaunal species of interest (Riftia pachyptila, Bathymodiolus thermophilus, Calyptogena magnifica) establish in distinct microhabitats, based on availability of <span class="hlt">vent</span> fluids that nourish endosymbiotic chemoautotrophs. We focus on how these establishment strategies interact with species fecundity, and with disturbance frequency and intensity, to determine what types of strategies can coexist in the system. We find that species must adopt sufficiently different fecundity-establishment strategies to coexist in the community, though strict tradeoffs between fecundity and establishment ability are not required. Additionally, we describe how the strategies that lead to coexistence depend on habitat availability and disturbance regime. Though other coexistence mechanisms may also play a role, our findings suggest why communities within a single biogeographic province may vary with spreading rate (as from N to S along the East Pacific Rise), and what strategies will allow coexistence under different disturbance regimes. Understanding how changes to disturbance regimes influence community composition is very important, as commercial mining interests are rapidly developing plans to exploit the rich mineral resources associated with <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and their activities will change the disturbance regime.</p> <div class="credits"> <p class="dwt_author">Miller, A. D.; Hsing, P.; Roxburgh, S. H.; Shea, K.; Fisher, C. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">257</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1994DSRI...41..993J"> <span id="translatedtitle">Biogeochemistry of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel communities: the deep-sea analogue to the intertidal zone</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Continuous measurements of sulfide, silicate and temperature were made in situ from the submersible Alvin in the Rose Garden and New <span class="hlt">Vent</span> <span class="hlt">hydrothermal</span> fields of the Galapagos Spreading Center. Continuous measurements of temperature also were made for an 18 day period in the Rose Garden field. The results demonstrate several adaptations that appear to have contributed to the success of the <span class="hlt">vent</span> mussel Bathymodiolus thermophilus in the Rose Garden. Dense clusters of B. thermophilus can disperse the <span class="hlt">hydrothermal</span> fluids laterally for distances of several meters. This results in a large increase in the area of the redox transition zone, where both dissolved oxygen and hydrogen sulfide are available. As a result, the animal communities can grow to occupy areas that would not otherwise provide adequate reduced substrates. Measurements of the temperature demonstrate a distinct tidal periodicity. This periodicity will result in a large range of environmental conditions within the <span class="hlt">vent</span> community. The mussel can tolerate these wide ranges in condition because of its ability to accept long periods of anoxia and to filter feed.</p> <div class="credits"> <p class="dwt_author">Johnson, Kenneth S.; Childress, James J.; Beehler, Carl L.; Sakamoto, Carole M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">258</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008JGRB..11311101D"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> sediment alteration at a seafloor <span class="hlt">vent</span> field: Grimsey Graben, Tjörnes Fracture Zone, north of Iceland</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">An active seafloor <span class="hlt">hydrothermal</span> system subjects the background sediments of the Grimsey Graben (Tjörnes Fracture Zone) to alteration that produces dissolution of the primary volcaniclastic matrix and replacement/precipitation of sulfides, sulfates, oxides, oxyhydroxides, carbonates and phyllosilicates. Three types of <span class="hlt">hydrothermal</span> alteration of the sediment are defined on the basis of the dominant <span class="hlt">hydrothermal</span> phyllosilicate formed: smectite, kaolinite, chlorite. The most common alteration is near-total conversion of the volcaniclastic material to smectite (95-116°C). The dominant smectite in the deepest sediments sampled is beidellite, which is replaced by montmorillonite and an intimate mixture of di- and tri-octahedral smectite up core. This gradual vertical change in smectite composition suggests an increase in the Mg supply upward, the result of sediment alteration by the ascending <span class="hlt">hydrothermal</span> fluids mixing with descending seawater. The vertical sequence kaolinite ? kaolinite-smectite mixed-layer ? smectite from bottom to top of a core, as well as the distinct zonation across the veins (kaolinite in the central zone ? kaolinite-smectite in the rim), suggests <span class="hlt">hydrothermal</span> transformation of the initially formed smectite to kaolinite through kaolinite-smectite mixed-layer (150-160°C). The cause of this transformation might have been an evolution of the fluids toward a slightly acidic pH or a relative increase in the Al concentration. Minor amounts of chamosite fill thin veins in the deepest sections of some cores. The gradual change from background clinochlore to chamosite across the veins suggests that chamosite replaces clinochlore as Fe is made available from <span class="hlt">hydrothermal</span> dissolution of detrital Fe-containing minerals. The internal textures, REE distribution patterns and the mode of occurrence of another magnesian phyllosilicate, kerolite, suggest that this mineral is the primary precipitate in the <span class="hlt">hydrothermal</span> chimneys rather than an alteration product in the sediment. Kerolite precipitated after and grew on anhydrite in the chimneys. Oxygen isotope ratios are interpreted to reflect precipitation of kerolite at temperatures of 302° to 336°C. It accumulated in the <span class="hlt">hydrothermal</span> mounds following the collapse of the chimneys and subsequent dissolution of anhydrite, thereby forming highly permeable aquifer layers underlying the <span class="hlt">vent</span> field. Some kerolite was redeposited in the near <span class="hlt">vent</span> field sediments by turbidity flows. The altered sediments are depleted in Mn, Rb and Sr, and enriched in U, Mo, Pb, Ba, As, Bi, Sb, Ag, Tl and Ga, as a result of leaching and precipitation, respectively. Conservative elements (Ti, Zr, Hf, Sc, Cr, Nb and Sn) are depleted or enriched in the altered sediments because of passive (precipitation or leaching of other phases) rather than active (because of their mobility) processes.</p> <div class="credits"> <p class="dwt_author">Dekov, Vesselin; Scholten, Jan; Garbe-SchöNberg, Carl-Dieter; Botz, Reiner; Cuadros, Javier; Schmidt, Mark; Stoffers, Peter</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">259</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/19422930"> <span id="translatedtitle">CHH family peptides from an 'eyeless' deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp, Rimicaris kairei: characterization and sequence analysis.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The crustacean eyestalk synthesizes and secretes several structurally-related peptides belonging to the crustacean hyperglycemic hormone (CHH) family, which are considered major physiological regulators during the crustacean life cycle. However, it is intriguing that eyestalks of many <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> crustaceans prove to have varying degrees of reduction. In the present study, we characterized full-length cDNAs encoding two important eyestalk hormones of the CHH family, CHH and VIH (vitellogenesis-inhibiting hormone), from the 'eyeless' <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp Rimicaris kairei. The two isoforms of Chh cDNA were 1027 and 1877 bp in length, respectively, and the deduced preprohormones contained 137 and 138 aa, respectively. The Vih cDNA was 907 bp in length, encoding a putative preprohormone of 113 aa. When compared with other known protein sequences of CHHs and VIHs, these polypeptides from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> show high similarity with their non-<span class="hlt">vent</span> counterparts. These results may provide evidence for the mechanisms of eyestalk reduction and <span class="hlt">vent</span>-adapting evolution of crustaceans. The <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp with reduced eyestalks may take a different evolutionary pathway than eyestalk-holding crustaceans, and the reduced eyestalks can be considered a good example for the investigation of the diversity of crustacean evolution in different environments. PMID:19422930</p> <div class="credits"> <p class="dwt_author">Qian, Ye-Qing; Dai, Li; Yang, Jin-Shu; Yang, Fan; Chen, Dian-Fu; Fujiwara, Yoshihiro; Tsuchida, Shinji; Nagasawa, Hiromichi; Yang, Wei-Jun</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">260</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1489322"> <span id="translatedtitle">Anaerobic Respiration on Tellurate and Other Metalloids in Bacteria from <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Fields in the Eastern Pacific Ocean</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">This paper reports the discovery of anaerobic respiration on tellurate by bacteria isolated from deep ocean (1,543 to 1,791 m) <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> worms. The first evidence for selenite- and vanadate-respiring bacteria from deep ocean <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> is also presented. Enumeration of the anaerobic metal(loid)-resistant microbial community associated with <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> animals indicates that a greater proportion of the bacterial community associated with certain <span class="hlt">vent</span> fauna resists and reduces metal(loid)s anaerobically than aerobically, suggesting that anaerobic metal(loid) respiration might be an important process in bacteria that are symbiotic with <span class="hlt">vent</span> fauna. Isolates from Axial Volcano and Explorer Ridge were tested for their ability to reduce tellurate, selenite, metavanadate, or orthovanadate in the absence of alternate electron acceptors. In the presence of metal(loid)s, strains showed an ability to grow and produce ATP, whereas in the absence of metal(loid)s, no growth or ATP production was observed. The protonophore carbonyl cyanide m-chlorophenylhydrazone depressed metal(loid) reduction. Anaerobic tellurate respiration will be a significant component in describing biogeochemical cycling of Te at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</p> <div class="credits"> <p class="dwt_author">Csotonyi, Julius T.; Stackebrandt, Erko; Yurkov, Vladimir</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_12");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" 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showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_15");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">261</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/16854265"> <span id="translatedtitle">Characterization and quantitation of a tertiary mixture of salts by Raman spectroscopy in simulated <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fluid.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">This article will demonstrate that Raman spectroscopy can be a useful tool for monitoring the chemical composition of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fluids in the deep ocean. <span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> systems are difficult to study because they are commonly found at depths greater than 1000 m under high pressure (200-300 bar) and <span class="hlt">venting</span> fluid temperatures are up to 400 degrees C. Our goal in this study was to investigate the use of Raman spectroscopy to characterize and quantitate three Raman-active salts that are among the many chemical building blocks of deep ocean <span class="hlt">vent</span> chemistry. This paper presents initial sampling and calibration studies as part of a multiphase project to design, develop, and deploy a submersible deep sea Raman instrument for in situ analysis of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> systems. Raman spectra were collected from designed sets of seawater solutions of carbonate, sulfate, and nitrate under different physical conditions of temperature and pressure. The role of multivariate analysis techniques to preprocess the spectral signals and to develop optimal calibration models to accurately estimate the concentrations of a set of mixtures of simulated seawater are discussed. The effects that the high-pressure and high-temperature environment have upon the Raman spectra of the analytes were also systematically studied. Information gained from these lab experiments is being used to determine design criteria and performance attributes for a deployable deep sea Raman instrument to study <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> systems in situ. PMID:16854265</p> <div class="credits"> <p class="dwt_author">Dable, Brian K; Love, Brooke A; Battaglia, Tina M; Booksh, Karl S; Lilley, Marvin D; Marquardt, Brian J</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">262</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013DSRI...82...73P"> <span id="translatedtitle">Genetic diversity of <span class="hlt">hydrothermal-vent</span> barnacles in Manus Basin</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We evaluated mitochondrial cytochrome oxidase I genetic diversity of two barnacle species (Eochionelasmus ohtai manusensis, Vulcanolepas cf. parensis) at three <span class="hlt">sites</span> in Manus Basin (Solwara 1, South Su, Solwara 8). There was no evidence for within-<span class="hlt">site</span> or between-<span class="hlt">site</span> genetic differentiation for either species. While E. ohtai manusensis showed limited genetic variation, V. cf. parensis showed greater variation, with sequences distributed between two divergent groups. Assuming the cytochrome oxidase I gene is not under selection, significantly negative Tajima's D in E. ohtai manusensis is consistent with a recent population expansion due to a bottleneck or founder effect, whereas V. cf. parensis (combined groups) did not depart from a stable effective population size. Considering the groups separately, V. cf. parensis Group 1 (but not Group 2) showed a negative Tajima's D, indicating these groups may have encountered different historical demographic conditions. Data reported here are part of a baseline study against which recovery of genetic diversity following mineral extraction at Solwara 1 can be measured.</p> <div class="credits"> <p class="dwt_author">Plouviez, Sophie; Schultz, Thomas F.; McGinnis, Gwendolyn; Minshall, Halle; Rudder, Meghan; Van Dover, Cindy L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">263</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22869718"> <span id="translatedtitle">Hydrogen-limited growth of hyperthermophilic methanogens at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Microbial productivity at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> is among the highest found anywhere in the deep ocean, but constraints on microbial growth and metabolism at <span class="hlt">vents</span> are lacking. We used a combination of cultivation, molecular, and geochemical tools to verify pure culture H(2) threshold measurements for hyperthermophilic methanogenesis in low-temperature <span class="hlt">hydrothermal</span> fluids from Axial Volcano and Endeavour Segment in the northeastern Pacific Ocean. Two Methanocaldococcus strains from Axial and Methanocaldococcus jannaschii showed similar Monod growth kinetics when grown in a bioreactor at varying H(2) concentrations. Their H(2) half-saturation value was 66 ?M, and growth ceased below 17-23 ?M H(2), 10-fold lower than previously predicted. By comparison, measured H(2) and CH(4) concentrations in fluids suggest that there was generally sufficient H(2) for Methanocaldococcus growth at Axial but not at Endeavour. Fluids from one <span class="hlt">vent</span> at Axial (Marker 113) had anomalously high CH(4) concentrations and contained various thermal classes of methanogens based on cultivation and mcrA/mrtA analyses. At Endeavour, methanogens were largely undetectable in fluid samples based on cultivation and molecular screens, although abundances of hyperthermophilic heterotrophs were relatively high. Where present, Methanocaldococcus genes were the predominant mcrA/mrtA sequences recovered and comprised ?0.2-6% of the total archaeal community. Field and coculture data suggest that H(2) limitation may be partly ameliorated by H(2) syntrophy with hyperthermophilic heterotrophs. These data support our estimated H(2) threshold for hyperthermophilic methanogenesis at <span class="hlt">vents</span> and highlight the need for coupled laboratory and field measurements to constrain microbial distribution and biogeochemical impacts in the deep sea. PMID:22869718</p> <div class="credits"> <p class="dwt_author">Ver Eecke, Helene C; Butterfield, David A; Huber, Julie A; Lilley, Marvin D; Olson, Eric J; Roe, Kevin K; Evans, Leigh J; Merkel, Alexandr Y; Cantin, Holly V; Holden, James F</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-08-21</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">264</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40471574"> <span id="translatedtitle">Experimentally induced endosymbiont loss and re-acquirement in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> bivalve Bathymodiolus azoricus</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Invertebrates harbouring endosymbiotic chemoautotroph bacteria are\\u000a widely distributed in a variety of reducing marine habitats, including\\u000a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. In these species mechanisms of symbiont\\u000a transmission are likely to be key elements of dispersal strategies that\\u000a remained partially unresolved because the early life stages are not\\u000a available for developmental studies. To study cessation and\\u000a re-establishment of symbiosis in the host</p> <div class="credits"> <p class="dwt_author">E Kadar; Raul Bettencourt; Valentina Costa; Ricardo Serrão Santos; Alexandre Lobo-da-Cunha; Paul Dando</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">265</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://pubs.er.usgs.gov/publication/70014063"> <span id="translatedtitle">Fossils of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> worms from Cretaceous sulfide ores of the Samail ophiolite, Oman</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">Fossil worm tubes of Cretaceous age preserved in the Bayda massive sulfide deposit of the Samail ophiolite, Oman, are apparently the first documented examples of fossils embedded in massive sulfide deposits from the geologic record. The geologic setting of the Bayda deposit and the distinctive mineralogic and textural features of the fossiliferous samples suggest that the Bayda sulfide deposit and fossil fauna are remnants of a Cretaceous sea-floor <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> similar to modern hot springs on the East Pacific Rise and the Juan de Fuca Ridge.</p> <div class="credits"> <p class="dwt_author">Haymon, R. M.; Koski, R. A.; Sinclair, C.</p> <p class="dwt_publisher"></p> <p class="publishDate">1984-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">266</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/7054142"> <span id="translatedtitle">Physiological characteristics of Thiomicrospira sp. Strain L-12 isolated from deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Growth of the obligately chemolithotrophic Thiomicrospira sp. strain L-12, isolated from a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> at a depth of 2,550 m in the Galapagos Rift region, was optimal at pH 8 and required 200 mM Na+ and divalent ions (Ca2+ and Mg2+). The organism was microaerophilic and tolerated 300 microM sulfide without a decrease in the rate of CO2 incorporation. Growth and CO2 incorporation occurred within the temperature range of 10 to 35 degrees C, with both optimal at 25 degrees C. At the in situ pressure of 250 atm. the rate of CO2 incorporation was reduced by 25% relative to that measured at 1 atm: it was entirely suppressed at 500 atm. The results of this physiological characterization suggest that Thiomicrospira sp. strain L-12 can be an active autotroph in the <span class="hlt">hydrothermal</span> environment. PMID:7054142</p> <div class="credits"> <p class="dwt_author">Ruby, E G; Jannasch, H W</p> <p class="dwt_publisher"></p> <p class="publishDate">1982-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">267</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2001AGUFMOS11A0349B"> <span id="translatedtitle">Effects of <span class="hlt">Hydrothermal</span> Alteration on In-situ Physical Properties in an Active <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Field - First Results of log Interpretation in ODP Hole 1189B</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">For the first time in the history of the Ocean Drilling Program (ODP), Leg 193 drilled into an active <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field associated with felsic magmatism at a convergent plate margin. The main scientific objectives were to study the subsurface volcanic architecture of the Pual ridge, delineate the structural and hydrologic characteristics of the PACMANUS active <span class="hlt">hydrothermal</span> system, and understand the mineralization and alteration patterns associated with vigorous high temperature fluid flow. Due to low core recovery, downhole logs provide the only continuous records of in-situ physical properties with depth hence the logs are of prime importance for achieving the scientific objectives of the leg. Downhole and core measurements from three holes located in the high temperature Roman Ruins <span class="hlt">hydrothermal</span> field (<span class="hlt">Site</span> 1189) show intense <span class="hlt">hydrothermal</span> alteration of dacites and rhyodacites and evidence of a mineralized stockwork zone. Downhole measurements from Hole 1189B show characteristic cyclic trends with electrical resistivity logs decreasing upwards. The upper parts of these cycles are characterized by increasing values of the photoelectric factor log, an indicator for the composition of the formation and slightly increased density values. The trends correlate with an increase in fracturing/brecciation observed in the electrical images of the FMS (Formation MicroScanner). However, higher values of density and photoelectric factor indicate an enrichment of heavier minerals in the upper parts of the cycles. Spectral gamma ray logs do not correlate with the cyclic variations in the resistivity logs. Uranium, a mobile element often used as indicator for alteration, gives a large contribution to the total gamma ray spectrum. Thus two different assemblages of logs may be used as indicator for alteration/mineralization in Hole 1189B. No correlation exists between the cyclic trends and the variations in the spectral gamma ray logs. This indicates that different alteration processes may be responsible for the cyclic trends and for the variations in the uranium log, respectively.</p> <div class="credits"> <p class="dwt_author">Bartetzko, A.; Iturrino, G. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">268</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2007AGUFM.B22D..08A"> <span id="translatedtitle">Energy Filtering Transmission Electron Tomography (EFTET) of Bacteria-Mineral Associations within the Deep sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Shrimp Rimicaris exoculata.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The chemical and temperature conditions around deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> are both dynamic and extreme, yet the shrimp Rimicaris exoculata flourishes around these environments on the Mid--Atlantic Ridge (MAR). Epibiotic bacteria and minerals found within the branchial chamber (BC) of the shrimp are of great interest in the search for a chemical model for the Rainbow MAR <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span>. Here we examine the close, three-- dimensional (3D) relationship between bacteria (on the inner surface of the BC wall) and the minerals that surround them. The morphology and chemistry of the minerals were analysed by Energy filtering Transmission Electron Microscopy (EFTEM, on a LEO--912 microscope) and X-ray Nano-analysis (EDXN, on a JEOL--2010 FEG microscope) respectively, and the 3D organization was determined by Transmission Electron Tomography (TET) and EFTET. Consecutive thin and semi--thin sections of 50--80nm (for EFTEM and EDXN) and 200--250nm (for TEM and EFTET) were cut through the BC cuticle and mounted on standard microscope grids. Sections were observed initially for morphology, to find broad relationships between bacteria and minerals. EFTET series acquisition was performed under cryo-conditions (-175°C) using a LEO-912 microscope. At each position of interest four tilt series were taken at two degree increments between -55° and +55° at various energy--losses: 1) zero--loss (ref); 2) 720 eV, 3) 690 eV and 4) 670 eV, to reconstruct the 3D location of iron. Tilted series were obtained using the ESIvision program (Soft--Imaging Software, Münster, Germany) with additional in--house scripts for automated acquisition. The 3D EFTET reconstruction volume was produced from the four tilted series using recently developed EFTET--J software (http://www.snv.jussieu.fr/~wboudier/softs.html). In many cases the observed minerals exhibit a sharp boundary against the bacteria, often with a substantial void between bacterial membrane/cell wall and mineral boundary. Mineral layering and zoning are also present. Our findings highlight the potential importance of iron as an energy source for Rimicaris exoculata epibionts at Rainbow, from their close association. The results from this study are contributing to the formulation of a chemical model for the Rainbow <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">site</span> (MAR).</p> <div class="credits"> <p class="dwt_author">Anderson, L. M.; Halary, S.; Lechaire, J.; Frébourg, G.; Boudier, T.; Zbinden, M.; Laval, J.; Marco, S.; Gaill, F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">269</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2007AGUFM.T23B1412T"> <span id="translatedtitle">Cemented Mounds Perched on the Kane Megamullion Detachment Surface: A New Manifestation of <span class="hlt">Hydrothermal</span> <span class="hlt">Venting</span>?</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">venting</span> has been widely investigated along the axes of mid-ocean ridges, but there has been little evidence of <span class="hlt">hydrothermal</span> flow directly associated with major normal faults. A notable exception is the TAG <span class="hlt">hydrothermal</span> field on the Mid-Atlantic Ridge (MAR), which is nucleated in the hanging wall above such a fault and which suggests that these fault/flow relations may be more common than heretofore recognized. We have encountered a probable example of such an association at Kane megamullion, which was formed by a long-lived (ca. 1.2 m.y.) detachment fault just south of Kane Fracture Zone on the MAR. The detachment fault exhumed sheeted dikes, gabbros, and mantle peridotites. Interpreted <span class="hlt">hydrothermal</span> cementation and sediments occur on the detachment surface and take two forms: 1) consolidated mounds of mixed rock debris and cemented sediment that appears to be enriched in Mn- and Fe-rich <span class="hlt">hydrothermal</span> precipitates, and 2) cemented, slabby sedimentary layers that also are Mn- and Fe-rich. The mounds have variable shapes and sizes. They range from conical to elongate or ridge-like and have heights from ca. 1 to 8 meters, with flank slopes of ca. 30 degrees to near-vertical. Compositions of the mound surfaces range from nearly pure rock debris (primarily basalt, but also occasional gabbro and serpentinite), to polymict breccia, to nearly pure sediment. Some of the sedimentary mounds show flow structures that resemble basalt pillows. The slabby sedimentary layers in some places occur on the flanks or at the bases of mounds and in other places occur on relatively smooth seafloor. The latter form is often cracked in linear to polygonal patterns, with upturned ridges produced at the cracks. We hypothesize that the debris mounds were produced where point-source fluid <span class="hlt">venting</span> occurred through the hanging wall close to the active trace of the detachment fault. The fluids cemented the hanging-wall debris and affixed it to the emerging footwall while the surrounding unconsolidated debris wasted away down the sloping fault surface. The predominantly sedimentary mounds, as well as the cemented slabby sediments, may have formed in association with diffuse <span class="hlt">venting</span> of low-temperature fluids through the footwall as it was exhumed and subjected to extensional bending stresses. If our hypothesis is correct, it indicates that primary pathways of fluid flow are intimately associated with major normal faults and probably also with fracture patterns in the emerging, bending footwalls of the faults.</p> <div class="credits"> <p class="dwt_author">Tucholke, B. E.; Dick, H. J.; Tivey, M. A.; Humphris, S. E.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">270</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFM.B43L..08B"> <span id="translatedtitle">Isotopic Approaches to Allying Productivity and Sulfur Metabolism in Three Symbiotic <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Molluscs</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Symbioses between animals and chemosynthetic bacteria predominate at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. In these associations, the endosymbiotic bacteria utilize chemical reductants for the energy to support autotrophy, providing primary nutrition for the host. Despite their ubiquity at <span class="hlt">vents</span> worldwide, little is known about the rates of productivity of these symbioses under different physico-chemical regimes or how their metabolism effects the local geochemical environment. To address this matter, we used high-pressure flow through incubations and stable isotopic tracers to maintain three genera of symbiotic mollusc - the gastropods Alviniconcha and Ifremeria, and the mussel Bathymodiolus - at <span class="hlt">vent</span>-like conditions. Via the incorporation of isotopically labeled compounds, we assessed their productivity when using different reduced sulfur species as reductants. Using cyclic voltammetry, mass spectrometry and discrete geochemical analyses, we concurrently measured their effect on sulfur flux from the vessels. We found that the symbionts of all three genera can support autotrophy with hydrogen sulfide and thiosulfate, though at different rates. Additionally, by examining the rate of isotopic incorporation into biomass, we revealed intra-generic variability in productivity among the individuals in our experimental assemblages that are likely related to differences in the geochemical regime along the length of reactor. These geochemical gradients are due to the activity of other individuals within the vessel, since those organisms closest to the influent of the <span class="hlt">vent</span>-like water had the highest measured carbon incorporation. Finally, we measured the uptake and excretion of sulfur species, which illustrate the degree to which these symbioses might impact local sulfur chemistry in situ. These experiments show that A) access to particular sulfur species differentially affects the productivity of <span class="hlt">vent</span> symbioses, suggesting that competition for these substrates, both within and between host genera, could play a role in the structure of these communities, and B) that these symbioses could play a role in altering the local geochemical regime, influencing the activity and distribution of other associated microorganisms including free-living bacteria.</p> <div class="credits"> <p class="dwt_author">Beinart, R.; Gartman, A.; Sanders, J. G.; Luther, G. W.; Girguis, P. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">271</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011AGUFM.V11E2547A"> <span id="translatedtitle">Microbially-Mediated Sulfur Oxidation in Diffuse <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Fluids at Axial Seamount, Juan de Fuca Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Diffusely <span class="hlt">venting</span> <span class="hlt">hydrothermal</span> fluids can act as a window to the subseafloor microbial environment, where chemically-reduced <span class="hlt">hydrothermal</span> fluids mixing with oxygenated seawater in the shallow crust creates chemical disequilibria that chemotrophic microorganisms can exploit for energy gain. At Axial Seamount, an active deep-sea volcano located on the Juan de Fuca Ridge, sulfide concentrations have been measured as high as 5770 ?M, and sulfide oxidation is quantitatively the most important chemical energy source for microbial metabolism. In addition, studies of microbial population structure indicate that diffuse fluids at Axial are dominated by putative sulfur- and sulfide-oxidizing bacteria belonging to the Epsilonproteobacteria. To further study this important microbial process, we surveyed diffuse <span class="hlt">vent</span> samples from Axial over a range of temperature, pH, and sulfide concentrations for the presence and expression of sulfide-oxidizing bacteria using a functional gene approach. Dissolved oxygen concentrations decrease exponentially above 40°C and lower the potential for sulfide oxidation, so we identified six <span class="hlt">sites</span> of different temperatures, two each in the low (< 30°C), medium (~30°C), and high temperature (30 - 50°C) range. The low temperature <span class="hlt">sites</span> had sulfide-to-temperature ratios of 1 - 26, the medium from 15 - 29, and the high from 26 - 36. PCR primers were designed to target the sulfur oxidation gene soxB specifically from Epsilonproteobacteria and five of the six <span class="hlt">sites</span> were positive for soxB in the DNA fraction. Bulk RNA was also extracted from the same <span class="hlt">sites</span> to examine in situ expression of soxB. Data from these analyses, along with quantification of the soxB gene abundance and expression using quantitative PCR, are currently being carried out. Together, this data set of soxB gene diversity, expression, and abundance along with geochemical data will allow us to quantitatively determine the functional dynamics of sulfide oxidation in the subseafloor at Axial Seamount. The molecular techniques developed in this project are also being applied to fluid samples collected from many of the same <span class="hlt">sites</span> at Axial following the recent 2011 eruption, as well as fluid samples collected from new snowblower <span class="hlt">vents</span> believed to be rich in sulfide-oxidizing bacteria.</p> <div class="credits"> <p class="dwt_author">Akerman, N. H.; Butterfield, D. A.; Huber, J. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">272</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40472893"> <span id="translatedtitle">Comparison of heat-shock responses between the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp Rimicaris exoculata and the related coastal shrimp Palaemonetes varians</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The deep-sea <span class="hlt">vent</span> shrimp Rimicaris exoculata is believed to occur at the hot end of the <span class="hlt">hydrothermal</span> biotope in order to provide essential elements to its epibiosis. Because it is found close to hot <span class="hlt">venting</span> water, R. exoculata lives in a highly fluctuating environment where temperature (2–40°C in the swarms) can exceed its critical maximal temperature (33–38.5±2°C). In order to</p> <div class="credits"> <p class="dwt_author">Delphine Cottin; Bruce Shillito; Thomas Chertemps; Sven Thatje; Nelly Léger; Juliette Ravaux</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">273</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://aem.asm.org/cgi/reprint/64/1/370.pdf"> <span id="translatedtitle">Stable-Carbon-Isotope Composition of Fatty Acids in <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Mussels Containing Methanotrophic and Thiotrophic Bacterial Endosymbionts</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Fatty acid biomarker analysis coupled with gas chromatography-isotope ratio mass spectrometry was used to confirm the presence of methanotrophic and thiotrophic bacterial endosymbionts in the tissues of a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel (Bathymodiolus sp.), collected from the Menez Gwen <span class="hlt">vent</span> field on the mid-Atlantic ridge. Monounsaturated (n-8) fatty acids, which are diagnostic of methanotrophic bacteria, were detected in all three types</p> <div class="credits"> <p class="dwt_author">DAVID W. POND; MICHAEL V. BELL; DAVID R. DIXON; ANTHONY E. FALLICK; MICHEL SEGONZAC; JOHN R. SARGENT</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">274</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.biomedcentral.com/content/pdf/1467-4866-9-6.pdf"> <span id="translatedtitle">Formation of Zn and Fe-sulfides near <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> at the Eastern Lau Spreading Center: implications for sulfide bioavailability to chemoautotrophs</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">BACKGROUND: The speciation of dissolved sulfide in the water immediately surrounding deep-ocean <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> is critical to chemoautotrophic organisms that are the primary producers of these ecosystems. The objective of this research was to identify the role of Zn and Fe for controlling the speciation of sulfide in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields at the Eastern Lau Spreading Center (ELSC) in</p> <div class="credits"> <p class="dwt_author">Heileen Hsu-Kim; Katherine M Mullaugh; Jeffrey J Tsang; Mustafa Yucel; George W Luther</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">275</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2006AGUFM.B34A..03F"> <span id="translatedtitle">Dissolved Carbon Species in Diffuse and Focused Flow <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> at the Main Endeavour Field, Northern Juan de Fuca Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The magmatic and tectonic event of 1999 had a significant impact on the chemical composition of <span class="hlt">vent</span> fluids issuing from the Main Endeavour Field (MEF), Juan de Fuca Ridge. Here, we report dissolved concentrations of H2, CO2, CO and C1-C3 alkanes measured in low and high-temperature <span class="hlt">hydrothermal</span> fluids collected in August 2005 during an RV Atlantis/DSV Alvin expedition at MEF. In comparison with time series data, temperatures of the 2005 <span class="hlt">vent</span> fluids were slightly lower than those recorded in the aftermaths of the tectonic event of 1999. The possible cooling of the <span class="hlt">hydrothermal</span> subseafloor reaction zone is consistent with the observed increase in dissolved Cl to pre-1999 values. Converging compositional trends to pre-1999 conditions are also suggested for dissolved CO2 concentrations (~20 mmol/kg) in Puffer, Sully, Bastille and S&M <span class="hlt">vent</span> fluids. In these focused flow and high-temperature <span class="hlt">vent</span> fluids, dissolved CO2 is in thermodynamic equilibrium with CO(aq). The systematics of organic species in diffuse flow fluids, however, appears to be closely related to processes occurring within the near-seafloor environment. For example, excess CO(aq) observed in the diffuse flow fluids at Easter Island is attributed to sluggish CO- CO2(aq) equilibria at low temperatures, suggesting <span class="hlt">hydrothermal</span> circulation of short-residence times. Short-lived <span class="hlt">hydrothermal</span> circulation is further supported by the nearly identical C1/(C2+C3) ratios between focused and diffuse flow fluids. Furthermore, alkane distribution in the MEF diffuse flow fluids suggests direct mixing between seawater and <span class="hlt">hydrothermal</span> fluid with minimal biological inputs, in contrast with the greater effect of microbial methanogenesis proposed in other ridge-crest <span class="hlt">hydrothermal</span> environments. Thus, the coupling of CO2(aq)-CO(aq) redox equilibrium with dissolved carbon species in low- temperature <span class="hlt">vent</span> fluids could provide a better understanding of the effect of subsurface microbial communities upon the composition of mid-ocean ridge <span class="hlt">hydrothermal</span> fluids.</p> <div class="credits"> <p class="dwt_author">Foustoukos, D. I.; Seyfried, W. E.; Ding, K.; Pester, N. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">276</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=154811"> <span id="translatedtitle">Coupling of Bacterial Endosymbiont and Host Mitochondrial Genomes in the <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Clam Calyptogena magnifica</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> clam Calyptogena magnifica (Bivalvia: Vesicomyidae) depends for its nutrition on sulfur-oxidizing symbiotic bacteria housed in its gill tissues. This symbiont is transmitted vertically between generations via the clam's eggs; however, it remains uncertain whether occasionally symbionts are horizontally transmitted or acquired from the environment. If symbionts are transmitted strictly vertically through the egg cytoplasm, inheritance of symbiont lineages should behave as if coupled to the host's maternally inherited mitochondrial DNA. This coupling would be obscured, however, with low rates of horizontal or environmental transfers, the equivalent of recombination between host lineages. Population genetic analyses of C. magnifica clams and associated symbionts from eastern Pacific <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> clearly supported the hypothesis of strictly maternal cotransmission. Host mitochondrial and symbiont DNA sequences were coupled in a clam population that was polymorphic for both genetic markers. These markers were not similarly coupled with sequence variation at a nuclear gene locus, as expected for a randomly mating sexual population. Phylogenetic analysis of the two cytoplasmic genes also revealed no evidence for recombination. The tight association between vesicomyid clams and their vertically transmitted bacterial endosymbionts is phylogenetically very young (<50 million years) and may serve as a model for the origin and evolution of eukaryotic organelles.</p> <div class="credits"> <p class="dwt_author">Hurtado, Luis A.; Mateos, Mariana; Lutz, Richard A.; Vrijenhoek, Robert C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">277</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2001AGUFMOS21B0444V"> <span id="translatedtitle">Measurements and Models of Heat Flux Magnitude and Variance from the Main Endeavour <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Precise measurement of the total heat flux from the Main Endeavour <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field (MEF) to the Northeast Pacific Ocean is confounded by tidal and topographically-controlled currents within the axial valley of the Endeavour segment. The magnitude of the total heat flux is dominated by vertical flux through a horizontal plane 75m above the <span class="hlt">vent</span> field, observed to be 590+/-51MW. The variance of the vertical flux, based on 12 surveys of velocity and hydrography over the MEF made by the Autonomous Benthic Explorer (ABE), compares well with the variance expected at the survey elevation from a model of axisymmetric <span class="hlt">hydrothermal</span> plumes. In contrast to the vertical flux, the horizontal flux of heat, advected laterally by currents through the MEF perimeter (<75m above the bottom), has a low observed mean magnitude of order 10MW. The horizontal flux, estimated by interpreting CTD and current data in multiple ways, has a high variance which is explained by an advection/diffusion, or ``puff,'' model initialized with current meter data acquired near the MEF. >http://www2.ocean.washington.edu/ ~scottv/research/2001agu/</a></p> <div class="credits"> <p class="dwt_author">Veirs, S. R.; Stahr, F. R.; McDuff, R. E.; Thomson, R. E.; Yoerger, D. R.; Bradley, A. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">278</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17291578"> <span id="translatedtitle">Deep sea immunity: unveiling immune constituents from the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Marine molluscs are subjected to constant microbial threats in their natural habitats. As a result, they represent suitable models for the study of the molecular mechanisms that govern defense reactions in marine organisms. To understand humoral and cellular defense reactions in animals defying extreme physical and chemical conditions we set out to investigate the deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus found in abundance at the Mid-Atlantic Ridge. In the present study, hemocytes were stimulated with compounds of microbial origin and cellular morphological alterations as well as the production of superoxide assessed. Consequently, zymosan, glucan and peptidoglycan were considered as potent inducers of cellular reactions for inducing drastic cell morphology changes and high levels of superoxide production. Furthermore, we have presented for the first time in a deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> animal, molecular evidence of the Rel-homology domain, a conserved motif present in all members of the Rel/nuclear-factor NF-kappaB family. Additionally we have demonstrated the occurrence of the antibacterial gene mytilin in Bathymodiolus azoricus gill tissues. Our results support the premise of an evolutionary conserved innate immune system in Bathymodiolus. Such system is seemingly homologous to that of Insects and other Bivalves and may involve the participation of NF-kappaB transcription factors and antibacterial genes. PMID:17291578</p> <div class="credits"> <p class="dwt_author">Bettencourt, Raul; Roch, Philippe; Stefanni, Sergio; Rosa, Domitília; Colaço, Ana; Santos, Ricardo Serrão</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-08-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">279</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3100261"> <span id="translatedtitle">Genetic diversity and demographic instability in Riftia pachyptila tubeworms from eastern Pacific <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Background Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> animals occupy patchy and ephemeral habitats supported by chemosynthetic primary production. Volcanic and tectonic activities controlling the turnover of these habitats contribute to demographic instability that erodes genetic variation within and among colonies of these animals. We examined DNA sequences from one mitochondrial and three nuclear gene loci to assess genetic diversity in the siboglinid tubeworm, Riftia pachyptila, a widely distributed constituent of <span class="hlt">vents</span> along the East Pacific Rise and Galápagos Rift. Results Genetic differentiation (FST) among populations increased with geographical distances, as expected under a linear stepping-stone model of dispersal. Low levels of DNA sequence diversity occurred at all four loci, allowing us to exclude the hypothesis that an idiosyncratic selective sweep eliminated mitochondrial diversity alone. Total gene diversity declined with tectonic spreading rates. The southernmost populations, which are subjected to superfast spreading rates and high probabilities of extinction, are relatively homogenous genetically. Conclusions Compared to other <span class="hlt">vent</span> species, DNA sequence diversity is extremely low in R. pachyptila. Though its dispersal abilities appear to be effective, the low diversity, particularly in southern hemisphere populations, is consistent with frequent local extinction and (re)colonization events.</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">280</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3105715"> <span id="translatedtitle">Comparative metagenomics of microbial communities inhabiting deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> chimneys with contrasting chemistries</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> chimneys harbor a high diversity of largely unknown microorganisms. Although the phylogenetic diversity of these microorganisms has been described previously, the adaptation and metabolic potential of the microbial communities is only beginning to be revealed. A pyrosequencing approach was used to directly obtain sequences from a fosmid library constructed from a black smoker chimney 4143-1 in the Mothra <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field at the Juan de Fuca Ridge. A total of 308?034 reads with an average sequence length of 227?bp were generated. Comparative genomic analyses of metagenomes from a variety of environments by two-way clustering of samples and functional gene categories demonstrated that the 4143-1 metagenome clustered most closely with that from a carbonate chimney from Lost City. Both are highly enriched in genes for mismatch repair and homologous recombination, suggesting that the microbial communities have evolved extensive DNA repair systems to cope with the extreme conditions that have potential deleterious effects on the genomes. As previously reported for the Lost City microbiome, the metagenome of chimney 4143-1 exhibited a high proportion of transposases, implying that horizontal gene transfer may be a common occurrence in the deep-sea <span class="hlt">vent</span> chimney biosphere. In addition, genes for chemotaxis and flagellar assembly were highly enriched in the chimney metagenomes, reflecting the adaptation of the organisms to the highly dynamic conditions present within the chimney walls. Reconstruction of the metabolic pathways revealed that the microbial community in the wall of chimney 4143-1 was mainly fueled by sulfur oxidation, putatively coupled to nitrate reduction to perform inorganic carbon fixation through the Calvin–Benson–Bassham cycle. On the basis of the genomic organization of the key genes of the carbon fixation and sulfur oxidation pathways contained in the large genomic fragments, both obligate and facultative autotrophs appear to be present and contribute to biomass production.</p> <div class="credits"> <p class="dwt_author">Xie, Wei; Wang, Fengping; Guo, Lei; Chen, Zeling; Sievert, Stefan M; Meng, Jun; Huang, Guangrui; Li, Yuxin; Yan, Qingyu; Wu, Shan; Wang, Xin; Chen, Shangwu; He, Guangyuan; Xiao, Xiang; Xu, Anlong</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" 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href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_16");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">281</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/21348883"> <span id="translatedtitle">Diversity and function in microbial mats from the Lucky Strike <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Diversity and function in microbial mats from the Lucky Strike <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field (Mid-Atlantic Ridge) were investigated using molecular approaches. DNA and RNA were extracted from mat samples overlaying <span class="hlt">hydrothermal</span> deposits and Bathymodiolus azoricus mussel assemblages. We constructed and analyzed libraries of 16S rRNA gene sequences and sequences of functional genes involved in autotrophic carbon fixation [forms I and II RuBisCO (cbbL/M), ATP-citrate lyase B (aclB)]; methane oxidation [particulate methane monooxygenase (pmoA)] and sulfur oxidation [adenosine-5'-phosphosulfate reductase (aprA) and soxB]. To gain new insights into the relationships between mats and mussels, we also used new domain-specific 16S rRNA gene primers targeting Bathymodiolus sp. symbionts. All identified archaeal sequences were affiliated with a single group: the marine group 1 Thaumarchaeota. In contrast, analyses of bacterial sequences revealed much higher diversity, although two phyla Proteobacteria and Bacteroidetes were largely dominant. The 16S rRNA gene sequence library revealed that species affiliated to Beggiatoa Gammaproteobacteria were the dominant active population. Analyses of DNA and RNA functional gene libraries revealed a diverse and active chemolithoautotrophic population. Most of these sequences were affiliated with Gammaproteobacteria, including <span class="hlt">hydrothermal</span> fauna symbionts, Thiotrichales and Methylococcales. PCR and reverse transcription-PCR using 16S rRNA gene primers targeted to Bathymodiolus sp. symbionts revealed sequences affiliated with both methanotrophic and thiotrophic endosymbionts. PMID:21348883</p> <div class="credits"> <p class="dwt_author">Crépeau, Valentin; Cambon Bonavita, Marie-Anne; Lesongeur, Françoise; Randrianalivelo, Henintsoa; Sarradin, Pierre-Marie; Sarrazin, Jozée; Godfroy, Anne</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">282</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24725254"> <span id="translatedtitle">Barite in <span class="hlt">hydrothermal</span> environments as a recorder of subseafloor processes: a multiple-isotope study from the Loki's Castle <span class="hlt">vent</span> field.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Barite chimneys are known to form in <span class="hlt">hydrothermal</span> systems where barium-enriched fluids generated by leaching of the oceanic basement are discharged and react with seawater sulfate. They also form at cold seeps along continental margins, where marine (or pelagic) barite in the sediments is remobilized because of subseafloor microbial sulfate reduction. We test the possibility of using multiple sulfur isotopes (?(34) S, ?(33) S, ?(36) S) of barite to identify microbial sulfate reduction in a <span class="hlt">hydrothermal</span> system. In addition to multiple sulfur isotopes, we present oxygen (?(18) O) and strontium ((87) Sr/(86) Sr) isotopes for one of numerous barite chimneys in a low-temperature (~20 °C) <span class="hlt">venting</span> area of the Loki's Castle black smoker field at the ultraslow-spreading Arctic Mid-Ocean Ridge (AMOR). The chemistry of the <span class="hlt">venting</span> fluids in the barite field identifies a contribution of at least 10% of high-temperature black smoker fluid, which is corroborated by (87) Sr/(86) Sr ratios in the barite chimney that are less radiogenic than in seawater. In contrast, oxygen and multiple sulfur isotopes indicate that the fluid from which the barite precipitated contained residual sulfate that was affected by microbial sulfate reduction. A sulfate reduction zone at this <span class="hlt">site</span> is further supported by the multiple sulfur isotopic composition of framboidal pyrite in the flow channel of the barite chimney and in the <span class="hlt">hydrothermal</span> sediments in the barite field, as well as by low SO4 and elevated H2 S concentrations in the <span class="hlt">venting</span> fluids compared with conservative mixing values. We suggest that the mixing of ascending H2 - and CH4 -rich high-temperature fluids with percolating seawater fuels microbial sulfate reduction, which is subsequently recorded by barite formed at the seafloor in areas where the flow rate is sufficient. Thus, low-temperature precipitates in <span class="hlt">hydrothermal</span> systems are promising <span class="hlt">sites</span> to explore the interactions between the geosphere and biosphere in order to evaluate the microbial impact on these systems. PMID:24725254</p> <div class="credits"> <p class="dwt_author">Eickmann, B; Thorseth, I H; Peters, M; Strauss, H; Bröcker, M; Pedersen, R B</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">283</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3622997"> <span id="translatedtitle">Draft Genome of Pseudomonas stutzeri Strain NF13, a Nitrogen Fixer Isolated from the Galapagos Rift <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Pseudomonas stutzeri strain NF13 was isolated from a water sample taken at a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> in the Galapagos rift. It was selected for its ability to metabolize sulfur compounds and to grow diazotrophically. Here, we report the first draft genome of a member of genomovar 19 of the species.</p> <div class="credits"> <p class="dwt_author">Pena, Arantxa; Busquets, Antonio; Gomila, Margarita; Mayol, Joan; Bosch, Rafael; Nogales, Balbina; Garcia-Valdes, Elena; Bennasar, Antonio</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">284</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3133302"> <span id="translatedtitle">Complete Genome Sequence of Hyperthermophilic Pyrococcus sp. Strain NA2, Isolated from a Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Area ?</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Pyrococcus sp. strain NA2, isolated from a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> sample, is a novel marine hyperthermophilic archaeon that grows optimally at 93°C. The complete genome sequence of the strain contains all the genes for the tricarboxylic acid cycle except for succinate dehydrogenase/fumarate reductase, but the genome does not encode proteins involved in polysaccharide utilization.</p> <div class="credits"> <p class="dwt_author">Lee, Hyun Sook; Bae, Seung Seob; Kim, Min-Sik; Kwon, Kae Kyoung; Kang, Sung Gyun; Lee, Jung-Hyun</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">285</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.mbari.org/staff/vrijen/PDFS/Won_2003MEb.pdf"> <span id="translatedtitle">Cytonuclear disequilibrium in a hybrid zone involving deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussels of the genus Bathymodiolus</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">A hybrid zone involving the deep-sea mussels, Bathymodiolus azoricus and B. puteoserpen- tis , was recently discovered at Broken Spur <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field (29 ° ° ° ° 10 '''' N, 43 ° ° ° ° 10 '''' W) along an intermediate segment of the Mid-Atlantic Ridge axis. Examination of nuclear (allozymes) and cytoplasmic (mitochondrial DNA) gene markers in a</p> <div class="credits"> <p class="dwt_author">Y. WON; S. J. HALLAM; G. D. OÕMULLAN; R. C. VRIJENHOEK</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">286</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ntis.gov/search/product.aspx?ABBR=ADA505050"> <span id="translatedtitle">Biotic and Abiotic Interactions of Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span>-Endemic Fish on the East Pacific Rise.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ntis.gov/search/index.aspx">National Technical Information Service (NTIS)</a></p> <p class="result-summary">A study of the ecology of fish endemic to <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> on the East Pacific Rise was undertaken utilizing a variety of techniques, focusing on the bythitid Thermichthys hollisi. Stable isotope and gut content analyses were used to elucidate prey choi...</p> <div class="credits"> <p class="dwt_author">K. L. Buckman</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">287</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1999E%26PSL.171...83B"> <span id="translatedtitle">Origin of trace gases in submarine <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> of the Kolbeinsey Ridge, north Iceland</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Two <span class="hlt">hydrothermal</span> fields of the Kolbeinsey Ridge area, north of Iceland, show <span class="hlt">vent</span> gas characteristics which can be related to the subsurface conditions. Helium isotopes ( R/Rair = 9.8, 10.9) indicate a mantle-derived origin and can be considered as a mixture of MORB helium and a deep-mantle plume helium component. The carbon isotope composition of CO 2 ranges between -2.4 and -7.8‰. The less negative ? 13C-CO 2 values were found at Grimsey. The data from Grimsey are very similar to those previously published and regarded as being characteristic for the Icelandic magmatic source. However, small amounts of biogenic CO 2 and/or subsurface calcite precipitation are responsible for the lighter isotope values of CO 2 from Kolbeinsey. CH 4/ 3He ratios which are higher than in MORB indicate an additional (sedimentary) methane source for Kolbeinsey and Grimsey <span class="hlt">hydrothermal</span> gases. The presence of higher hydrocarbons up to butane, together with the carbon isotope values of methane (? 13C = -26.1 to -39.8‰) suggest a probably high-mature organic source within thick sediments of the Tjörnes Fracture Zone and smaller depressions on the west side of the Kolbeinsey Ridge crest. Geochemical characteristics of hydrocarbons present in KR <span class="hlt">hydrothermal</span> fluids are, however, typical for a mixed (thermogenic and high-temperature <span class="hlt">hydrothermal</span>, e.g. EPR-type) origin. Moreover, it is likely that secondary processes such as bacterial oxidation and thermal cracking determined the geochemical characteristics of the gases.</p> <div class="credits"> <p class="dwt_author">Botz, R.; Winckler, G.; Bayer, R.; Schmitt, M.; Schmidt, M.; Garbe-Schönberg, D.; Stoffers, P.; Kristjansson, J. K.</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">288</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/9302103"> <span id="translatedtitle">Retinal anatomy of Chorocaris chacei, a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp from the Mid-Atlantic Ridge.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Exploration of deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> over the past quarter century has revealed that they support unique and diverse biota. Despite the harsh nature of the environment, <span class="hlt">vents</span> along the Mid-Atlantic Ridge are dominated by large masses of highly motile Bresiliid shrimp. Until 1989, when it was discovered that the <span class="hlt">vent</span> shrimp Rimicaris exoculata possesses a hypertrophied dorsal eye, many believed that animals populating <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> were blind. Chorocaris chacei (originally designated Rimicaris chacei) is a Bresiliid shrimp found at <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields along the Mid-Atlantic Ridge. Like R. exoculata, C. chacei has a hypertrophied retina that appears to be specialized to detect the very small amount of light emitted from the orifices of black smoker <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> chimneys. C. chacei lacks the sophisticated compound eyes common to other decapod crustaceans. Instead, it has a smooth cornea, with no dioptric apparatus, apposed by a tightly packed, massive array of photosensitive membrane. Photoreceptors in the C. chacei retina are segmented into a hypertrophied region that contains the photosensitive membrane and an atrophied cell body that is roughly ten times smaller in volume than the photosensitive segment. The microvillar photosensitive membrane is consistent in structure and ultrastructure with the rhabdoms of decapod and other invertebrate retinas. However, the volume density of photosensitive membrane (> or =60%) exceeds that typically observed in invertebrate retinas. The reflecting pigment cells commonly found in decapod retinas are represented in the form of a matrix of white diffusing cells that exhibit Tyndall scattering and form an axial sheath around the photoreceptors. All photoreceptor screening pigment granules and screening pigment cells are restricted to the region below the photoreceptor nuclei and are thereby removed from the path of incident light. No ultrastructural evidence of rhythmic cycling of photosensitive membrane was observed. The morphological adaptations observed in the C. chacei retina suggest that it is a high-sensitivity photodetector that is of functional significance to the animal. PMID:9302103</p> <div class="credits"> <p class="dwt_author">Lakin, R C; Jinks, R N; Battelle, B A; Herzog, E D; Kass, L; Renninger, G H; Chamberlain, S C</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-09-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">289</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012GGG....13.AG14O"> <span id="translatedtitle">Geological context and <span class="hlt">vents</span> morphology of the ultramafic-hosted Ashadze <span class="hlt">hydrothermal</span> areas (Mid-Atlantic Ridge 13°N)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Recent ROV dives and high-resolution bathymetric data acquired over the Ashadze fields on the Mid-Atlantic Ridge (13°N) allow us to derive constraints on the regional and local geological setting of ultramafic-hosted <span class="hlt">hydrothermal</span> fields. The active <span class="hlt">vent</span> fields of Ashadze <span class="hlt">hydrothermal</span> fields are located in the western axial valley wall, downslope from the termination of a prominent corrugated surface and in a transitional domain with respect to ridge segmentation. The study of the shipboard and ROV bathymetry shows that decameter (100 m by 60 m) to kilometer-scaled rockslides shape the axial valley wall slopes in this region. The Ashadze 1 <span class="hlt">vent</span> field occurs on a coherent granular landslide rock mass that is elongated in an E-W direction. The Ashadze 1 <span class="hlt">vent</span> field comprises hundreds of active and inactive sulfide chimneys. The Ashadze 2 <span class="hlt">vent</span> field is located in a NNE-trending linear depression which separates outcrops of gabbros and serpentinized peridotites. Active black smokers in the Ashadze 2 field are located on ultramafic substratum in a 40-m diameter crater, 5-m deep. This crater recalls similar structures described at some <span class="hlt">vents</span> of the Logatchev <span class="hlt">hydrothermal</span> field (Mid-Atlantic Ridge 15°N). We discuss the mode of formation for these craters, as well as that for a breadcrust-like array of radial fissures identified at Ashadze 1. We propose that <span class="hlt">hydrothermalism</span> at Ashadze can be an explosive phenomena associated with geyser-like explosions. Our study also constrains the geological and geophysical context of the ultramafic-hosted Ashadze <span class="hlt">hydrothermal</span> system that may use the oceanic detachment fault as a preferred permeability conduit.</p> <div class="credits"> <p class="dwt_author">OndréAs, HéLèNe; Cannat, Mathilde; Fouquet, Yves; Normand, Alain</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">290</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1166624"> <span id="translatedtitle">An obligately photosynthetic bacterial anaerobe from a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The abundance of life on Earth is almost entirely due to biological photosynthesis, which depends on light energy. The source of light in natural habitats has heretofore been thought to be the sun, thus restricting photosynthesis to solar photic environments on the surface of the Earth. If photosynthesis could take place in geothermally illuminated environments, it would increase the diversity of photosynthetic habitats both on Earth and on other worlds that have been proposed to possibly harbor life. Green sulfur bacteria are anaerobes that require light for growth by the oxidation of sulfur compounds to reduce CO2 to organic carbon, and are capable of photosynthetic growth at extremely low light intensities. We describe the isolation and cultivation of a previously unknown green sulfur bacterial species from a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span>, where the only source of light is geothermal radiation that includes wavelengths absorbed by photosynthetic pigments of this organism.</p> <div class="credits"> <p class="dwt_author">Beatty, J. Thomas; Overmann, Jorg; Lince, Michael T.; Manske, Ann K.; Lang, Andrew S.; Blankenship, Robert E.; Van Dover, Cindy L.; Martinson, Tracey A.; Plumley, F. Gerald</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">291</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2808221"> <span id="translatedtitle">Protection mechanisms of the iron-plated armor of a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> gastropod</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Biological exoskeletons, in particular those with unusually robust and multifunctional properties, hold enormous potential for the development of improved load-bearing and protective engineering materials. Here, we report new materials and mechanical design principles of the iron-plated multilayered structure of the natural armor of Crysomallon squamiferum, a recently discovered gastropod mollusc from the Kairei Indian <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field, which is unlike any other known natural or synthetic engineered armor. We have determined through nanoscale experiments and computational simulations of a predatory attack that the specific combination of different materials, microstructures, interfacial geometries, gradation, and layering are advantageous for penetration resistance, energy dissipation, mitigation of fracture and crack arrest, reduction of back deflections, and resistance to bending and tensile loads. The structure-property-performance relationships described are expected to be of technological interest for a variety of civilian and defense applications.</p> <div class="credits"> <p class="dwt_author">Yao, Haimin; Dao, Ming; Imholt, Timothy; Huang, Jamie; Wheeler, Kevin; Bonilla, Alejandro; Suresh, Subra; Ortiz, Christine</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">292</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009AGUFM.V51D1738P"> <span id="translatedtitle">Biogeography of Thermococcus isolates from five geographically isolated <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> systems</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In terrestrial environments, islands can be restrictive geographic barriers that lead to the divergence of species. In marine environments, <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> systems and the organisms associated with them can exist as island-like ecosystems geographically isolated from one another. Multiple isolates of the thermophilic Archaeal genus Thermococcus, cultured from samples collected from the Juan de Fuca Ridge, East Pacific Rise, Mid-Atlantic Ridge, Loihi Seamount, and Mariana Arc, were analyzed to determine the relationship between geographic distribution and relatedness. DNA extracts from Thermococcus isolates were analyzed through amplified fragment length polymorphism (AFLP) which utilizes genetic markers across an entire genome. This allows for the detection of minor differences in genomes and the differentiation of isolates at the strain level. Recent isolates from Loihi Seamount, Hawaii, and NW Eifuku and Daikoku Seamounts, Mariana Arc are currently being further characterized. Observed genetic variation of isolates supports the general pattern of endemic populations resulting from geographic isolation.</p> <div class="credits"> <p class="dwt_author">Price, M. T.; Moyer, C. L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">293</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/15967984"> <span id="translatedtitle">An obligately photosynthetic bacterial anaerobe from a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The abundance of life on Earth is almost entirely due to biological photosynthesis, which depends on light energy. The source of light in natural habitats has heretofore been thought to be the sun, thus restricting photosynthesis to solar photic environments on the surface of the Earth. If photosynthesis could take place in geothermally illuminated environments, it would increase the diversity of photosynthetic habitats both on Earth and on other worlds that have been proposed to possibly harbor life. Green sulfur bacteria are anaerobes that require light for growth by the oxidation of sulfur compounds to reduce CO2 to organic carbon, and are capable of photosynthetic growth at extremely low light intensities. We describe the isolation and cultivation of a previously unknown green sulfur bacterial species from a deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span>, where the only source of light is geothermal radiation that includes wavelengths absorbed by photosynthetic pigments of this organism. PMID:15967984</p> <div class="credits"> <p class="dwt_author">Beatty, J Thomas; Overmann, Jörg; Lince, Michael T; Manske, Ann K; Lang, Andrew S; Blankenship, Robert E; Van Dover, Cindy L; Martinson, Tracey A; Plumley, F Gerald</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-06-28</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">294</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2005AGUFM.T31A0476F"> <span id="translatedtitle">High-Resolution Micro-Bathymetry Mapping in the Lau Basin: Examples From the Tui Malila and Mariner <span class="hlt">Vent</span> <span class="hlt">Sites</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">High-resolution SM2000 (200 kHz) multibeam sonar data were collected at six <span class="hlt">vent</span> areas on the Lau Basin spreading center in April 2005. Data were acquired during near-bottom surveys conducted with the ROV Jason II at altitudes ranging from 5 to 20 m. High altitude (20 m) bathymetric surveys were complemented by near-bottom visual surveys, which provided ground-truth observations of the seafloor. Combined with Doppler and Long Baseline (LBL) Navigation, these bathymetry data provide sub-meter resolution of seafloor features, and reveal individual <span class="hlt">vent</span> structures, faults and fissures. We present bathymetry data from two <span class="hlt">sites</span> located 22 km apart, which are geologically and biologically distinct and exhibit contrasts in <span class="hlt">venting</span> styles and biota. The Mariner <span class="hlt">vent</span> field contains massive <span class="hlt">vent</span> structures, many of which are taller than 25 m, with active <span class="hlt">venting</span> from their bases and sides. Fluids exit as vigorous, high-temperature (< 363°C) black smoker fluids through chalcopyrite-lined conduits, and as less focused flow from porous beehive structures. Inactive structures are friable and are composed of iron- and copper-oxides. There was little evidence of faulting or fracture at the <span class="hlt">vent</span> field, but we note the presence of collapsed volcanic dome structures. The <span class="hlt">vent</span> fauna at Mariner is very limited; only Bythograeid and Galatheid crabs, and one Brisingid Seastar, were found. Tui Malila, by contrast, is characterized by shorter and wider branched <span class="hlt">vent</span> structures with coalesced spires, the tops of which were actively <span class="hlt">venting</span>. There is extensive faulting and fracture at this <span class="hlt">site</span>, as well as a number of large flanges and areas of diffuse flow. At Tui Malila fluids exit tall structures through chalcopyrite- and zinc-lined conduits (at temperatures < 312°C), from beneath flanges, and directly from andesite. <span class="hlt">Hydrothermal</span> breccias are also present. Tui Malila hosts a more typical <span class="hlt">vent</span> community, with greater abundances of both Bythograeid and Galatheid crabs, mostly within 4 m of the <span class="hlt">vent</span> field. Ifremeria Nautilei and Bathymodiolus Brevior were prolific within 2 m of the <span class="hlt">vent</span> field, and sponges and anemones abundant from 4 to 32 m away.</p> <div class="credits"> <p class="dwt_author">Ferrini, V.; Sterling, A.; Martinez, F.; Tivey, M. K.; Mottl, M.; Kim, S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">295</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/5108416"> <span id="translatedtitle">Distribution and composition of <span class="hlt">hydrothermal</span> plume particles from the ASHES <span class="hlt">vent</span> field at Axial Volcano, Juan de Fuca Ridge. [Axial Seamount <span class="hlt">Hydrothermal</span> Emission Study</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">In 1986 and 1987, buoyant and neutrally buoyant <span class="hlt">hydrothermal</span> plume particles from the ASHES <span class="hlt">vent</span> field within Axial Volcano were sampled to study their variations in composition with height above the seafloor. Individual mineral phases were identified using standard X ray diffraction procedures. Elemental composition and particle morphologies were determined by X ray fluorescence spectrometry and scanning electron microscopy/X ray energy spectrometry techniques. The <span class="hlt">vent</span> particles were primarily composed of sphalerite, anhydrite, pyrite, pyrrhotite, chalcopyrite, barite, hydrous iron oxides, and amorphous silica. Grain size analyses of buoyant plume particles showed rapid particle growth in the first few centimeters above the <span class="hlt">vent</span> orifice, followed by differential sedimentation of the larger sulfide and sulfate minerals out of the buoyant plume. The neutrally buoyant plume consisted of a lower plume, which was highly enriched in Fe, S, Zn, and Cu, and an upper plume, which was highly enriched in Fe and Mn. The upper plume was enriched in Fe and Mn oxyhydroxide particles, and the lower plume was enriched in suspended sulfide particles in addition to the Fe and Mn oxyhydroxide particles. The chemical data for the water column particles indicate that chemical scavenging and differential sedimentation processes are major factors controlling the composition of the dispersing <span class="hlt">hydrothermal</span> particles. Short-term sediment trap experiments indicate that the fallout from the ASHES <span class="hlt">vent</span> field is not as large as some of the other <span class="hlt">vent</span> fields on the Juan de Fuca Ridge.</p> <div class="credits"> <p class="dwt_author">Feely, R.A.; Geiselman, T.L.; Baker, E.T.; Massoth, G.J. (NOAA, Seattle, WA (United States)); Hammond, S.R. (NOAA, Newport, OR (United States))</p> <p class="dwt_publisher"></p> <p class="publishDate">1990-08-10</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">296</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/10603254"> <span id="translatedtitle">Miocene radiation of deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp (Caridea: Bresiliidae): evidence from mitochondrial cytochrome oxidase subunit I.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The evolutionary history of deep-sea shrimp (Caridea: Bresiliidae) inhabiting deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> and hydrocarbon seep environments was assessed using the mitochondrial Cytochrome c Oxidase subunit I (COI) gene (600 bp). Phylogenetic analyses (parsimony, likelihood, and neighbor-joining) recovered three distinct clades (A, Rimicaris/Chorocaris/Opaepele; B, Alvinocaris; and C, Mirocaris) consistent with higher level taxonomy based on morphology. However, robust phylogenetic results suggested that Chorocaris is paraphyletic and that Mirocaris fortunata and M. keldyshi may not be genetically distinct. A Kishino-Hasegawa likelihood approach was used to test alternative phylogenetic hypotheses based on biogeography and morphology. Evolutionary relationships of <span class="hlt">vent</span>-endemic shrimp species did not appear to be correlated either with their extant biogeographic distribution or with the history of sea floor spreading. Additionally, COI data suggested that these <span class="hlt">vent</span>-endemic organisms are not remnants of a Mesozoic <span class="hlt">vent</span> assemblage; instead, they radiated in the Miocene. PMID:10603254</p> <div class="credits"> <p class="dwt_author">Shank, T M; Black, M B; Halanych, K M; Lutz, R A; Vrijenhoek, R C</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">297</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3988086"> <span id="translatedtitle">Exopolysaccharides Isolated from <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Bacteria Can Modulate the Complement System</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The complement system is involved in the defence against bacterial infection, or in the elimination of tumour cells. However, disturbances in this system contributes to the pathogenesis of various inflammatory diseases. The efficiency of therapeutic anti-tumour antibodies is enhanced when the complement system is stimulated. In contrast, cancer cells are able to inhibit the complement system and thus proliferate. Some marine molecules are currently being developed as new drugs for use in humans. Among them, known exopolyssacharides (EPSs) generally originate from fungi, but few studies have been performed on bacterial EPSs and even fewer on EPSs extracted from deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> microbes. For use in humans, these high molecular weight EPSs must be depolymerised. Furthermore, the over-sulphation of EPSs can modify their biological activity. The aim of this study was to investigate the immunodulation of the complement system by either native or over-sulphated low molecular weight EPSs isolated from <span class="hlt">vent</span> bacteria in order to find pro or anti-activators of complement.</p> <div class="credits"> <p class="dwt_author">Courtois, Anthony; Berthou, Christian; Guezennec, Jean</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">298</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003DSRI...50..269Z"> <span id="translatedtitle">Mineralogical gradients associated with alvinellids at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Alvinella pompejana and Alvinella caudata live in organic tubes on active sulphide chimney walls at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. These polychaete annelids are exposed to extreme thermal and chemical gradients and to intense mineral precipitation. This work points out that mineral particles associated with Pompeii worm ( A. pompejana and A. caudata) tubes constitute useful markers for evaluating the chemical characteristics of their micro-environment. The minerals associated with these worm tubes were analysed on samples recovered from an experimental alvinellid colony, at different locations in the <span class="hlt">vent</span> fluid-seawater interface. Inhabited tubes from the most upper and lower parts of the colony were analysed by light and electron microscopies, X-ray microanalysis and X-ray diffraction. A change was observed from a Fe-Zn-S mineral assemblage to a Zn-S assemblage at the millimeter scale from the outer to the inner face of a tube. A similar gradient in proportions of minerals was observed at a decimeter scale from the lower to the upper part of the colony. The marcasite/pyrite ratio of iron disulphides also displays a steep decrease along the few millimeters adjacent to the external tube surface. The occurrence of these gradients indicates that the micro-environment within the tube differs from that outside the tube, and suggests that the tube wall acts as an efficient barrier to the external environment.</p> <div class="credits"> <p class="dwt_author">Zbinden, Magali; Le Bris, Nadine; Compère, Philippe; Martinez, Isabelle; Guyot, François; Gaill, Françoise</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-02-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">299</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/15315674"> <span id="translatedtitle">Distinct patterns of genetic differentiation among annelids of eastern Pacific <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Population genetic and phylogenetic analyses of mitochondrial COI from five deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> annelids provided insights into their dispersal modes and barriers to gene flow. These polychaetes inhabit <span class="hlt">vent</span> fields located along the East Pacific Rise (EPR) and Galapagos Rift (GAR), where hundreds to thousands of kilometers can separate island-like populations. Long-distance dispersal occurs via larval stages, but larval life histories differ among these taxa. Mitochondrial gene flow between populations of Riftia pachyptila, a siboglinid worm with neutrally buoyant lecithothrophic larvae, is diminished across the Easter Microplate region, which lies at the boundary of Indo-Pacific and Antarctic deep-sea provinces. Populations of the siboglinid Tevnia jerichonana are similarly subdivided. Oasisia alvinae is not found on the southern EPR, but northern EPR populations of this siboglinid are subdivided across the Rivera Fracture Zone. Mitochondrial gene flow of Alvinella pompejana, an alvinellid with large negatively buoyant lecithotrophic eggs and arrested embryonic development, is unimpeded across the Easter Microplate region. Gene flow in the polynoid Branchipolynoe symmytilida also is unimpeded across the Easter Microplate region. However, A. pompejana populations are subdivided across the equator, whereas B. symmitilida populations are subdivided between the EPR and GAR axes. The present findings are compared with similar evidence from codistributed species of annelids, molluscs and crustaceans to identify potential dispersal filters in these eastern Pacific ridge systems. PMID:15315674</p> <div class="credits"> <p class="dwt_author">Hurtado, L A; Lutz, R A; Vrijenhoek, R C</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">300</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/11903895"> <span id="translatedtitle">A hybrid zone between <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussels (Bivalvia: Mytilidae) from the Mid-Atlantic Ridge.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">This study provides the first example of a hybrid zone between animal taxa distributed along the mid-ocean ridge system. We examined the distribution and genetic structure of deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussels (Bivalvia: Mytilidae) along a 2888-km portion of the Mid-Atlantic Ridge between 37 degrees 50' N and 14 degrees 45' N latitude. Mitochondrial DNA (mtDNA), allozymes and multivariate-morphometric evidence discriminated between individuals of a northern species, Bathymodiolus azoricus, and a southern species, B. puteoserpentis, that were separated by an intermediate ridge segment almost devoid of mussels. A small sample of mussels from Broken Spur, a <span class="hlt">vent</span> locality along this intermediate zone, revealed a mixed population with gene frequencies and morphology that were broadly intermediate to those of the northern and southern species. Multilocus clines in mtDNA and allozyme frequencies were centred over the intermediate zone. We consider intrinsic and extrinsic processes that might limit genetic exchange across this hybrid zone. PMID:11903895</p> <div class="credits"> <p class="dwt_author">O'Mullan, G D; Maas, P A; Lutz, R A; Vrijenhoek, R C</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-12-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_14");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' 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id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_15");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a style="font-weight: bold;">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_17");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">301</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3721115"> <span id="translatedtitle">Metatranscriptomics reveal differences in in situ energy and nitrogen metabolism among <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> snail symbionts</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Despite the ubiquity of chemoautotrophic symbioses at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, our understanding of the influence of environmental chemistry on symbiont metabolism is limited. Transcriptomic analyses are useful for linking physiological poise to environmental conditions, but recovering samples from the deep sea is challenging, as the long recovery times can change expression profiles before preservation. Here, we present a novel, in situ RNA sampling and preservation device, which we used to compare the symbiont metatranscriptomes associated with Alviniconcha, a genus of <span class="hlt">vent</span> snail, in which specific host–symbiont combinations are predictably distributed across a regional geochemical gradient. Metatranscriptomes of these symbionts reveal key differences in energy and nitrogen metabolism relating to both environmental chemistry (that is, the relative expression of genes) and symbiont phylogeny (that is, the specific pathways employed). Unexpectedly, dramatic differences in expression of transposases and flagellar genes suggest that different symbiont types may also have distinct life histories. These data further our understanding of these symbionts' metabolic capabilities and their expression in situ, and suggest an important role for symbionts in mediating their hosts' interaction with regional-scale differences in geochemistry.</p> <div class="credits"> <p class="dwt_author">Sanders, J G; Beinart, R A; Stewart, F J; Delong, E F; Girguis, P R</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">302</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011GeoRL..3813320A"> <span id="translatedtitle">Strong seismic heterogeneity in layer 2A near <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> at the Mid-Atlantic Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We present a high-resolution 3D seismic image beneath the Lucky Strike volcano on the Mid-Atlantic Ridge using streamer tomography. To obtain a high-resolution ray coverage in layer 2A, we first downward continue the multichannel seismic (MCS) data close to the seafloor generating a synthetic ocean bottom experiment (SOBE) and then apply 3D travel-time tomography. We find that the upper crust is laterally heterogeneous on 2-3 km scale, with unusually low velocities (1.8-2.2 km.s-1) in the upper few hundred meters beneath the Lucky Strike volcanic edifices, but normal layer 2A velocities (2.2-3.0 km.s-1) beneath the lava lake. The low velocities could be due to extremely high porosity (25-50%) in recently erupted, highly fractured pillow lavas. The <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields seem to lie at the boundary between the high-porosity edifices and the lower porosity lava lake. We have also imaged a reflector at the base of the volcanic edifices that is distinct from the deeper high-velocity gradient transition zone from layer 2A to 2B imaged so far. The new technique provides an image of the oceanic crust with resolutions comparable to that of seafloor geology, leading to new insight about volcanic and <span class="hlt">hydrothermal</span> processes.</p> <div class="credits"> <p class="dwt_author">Arnulf, A. F.; Singh, S. C.; Harding, A. J.; Kent, G. M.; Crawford, W.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">303</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1990JGR....9512961T"> <span id="translatedtitle">Observations on the effects of sampling on <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> habitat and fauna of Axial Seamount, Juan de Fuca Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The study of <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> is conducted mostly through samples collected by submersible. Two <span class="hlt">vent</span> fields on Axial Seamount, Juan de Fuca Ridge, have been visited at least three times each between 1983 and 1988 by Canadian, American, and Soviet workers. This study offers some comparative observations, but controlled experimentation was not conducted. After 5 years, unsampled <span class="hlt">vents</span> appeared unchanged in gross aspects such as animal abundance, but those that had been sampled were depleted or gone. Changes at a sulphide deposit inhabited by tube worms were documented by a time-lapse camera over two years during which time both sulphide area and tube worm coverage decreased most dramatically immediately after sampling with submersibles. Vestimentiferans displaced from fluid flows were able to survive several weeks but were rarely seen emergent. Surfaces denuded of tube worms were repopulated by polychaete species previously known at this <span class="hlt">vent</span>. Recruitment by tube worms to either the denuded mound or to settling plates was negligible. Some <span class="hlt">vent</span> animals may be highly sensitive to disruption despite the naturally unstable nature of their habitat. Effects of sampling on long-term studies of <span class="hlt">vent</span> animals, sulphide deposits, and <span class="hlt">vent</span> effluents need serious consideration.</p> <div class="credits"> <p class="dwt_author">Tunnicliffe, Verena</p> <p class="dwt_publisher"></p> <p class="publishDate">1990-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">304</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=107066"> <span id="translatedtitle">Cloning and Sequencing of a Form II Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase from the Bacterial Symbiont of the <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Tubeworm Riftia pachyptila</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The bacterial symbiont of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> tubeworm fixes carbon via the Calvin-Benson cycle and has been shown previously to express a form II ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO). The gene cbbM, which encodes this enzyme, has been cloned and sequenced. The gene has the highest identity with the cbbM gene from Rhodospirillum rubrum, and analysis of the inferred amino acid sequence reveals that all active-<span class="hlt">site</span> residues are conserved. This is the first form II RubisCO cloned and sequenced from a chemoautotrophic symbiont and from a deep-sea organism.</p> <div class="credits"> <p class="dwt_author">Robinson, Jonathan J.; Stein, Jeffrey L.; Cavanaugh, Colleen M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">305</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/9628005"> <span id="translatedtitle">Molecular systematics of shrimp (Decapoda: Bresiliidae) from deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, I: Enigmatic "small orange" shrimp from the Mid-Atlantic Ridge are juvenile Rimicaris exoculata.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Independent species descriptions of a "small orange" caridean shrimp found at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> along the Mid-Atlantic Ridge have created the synonymous names Iorania concordia Vereshchaka 1996b and Rimicaris aurantiaca Martin et al. 1997. Our genetic analyses involving allozymes and mitochondrial DNA sequences reveal that the "small orange" shrimp described in these studies are a juvenile form of Rimicaris exoculata Williams and Rona, a species commonly found at these <span class="hlt">sites</span>. In light of this result, we reconsider the life history and ecologic characteristics of juvenile and adult stages of Rimicaris exoculata. PMID:9628005</p> <div class="credits"> <p class="dwt_author">Shank, T M; Lutz, R A; Vrijenhoek, R C</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">306</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1988DSRA...35.1769F"> <span id="translatedtitle">Microhabitat variation in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel, Bathymodiolus thermophilus, at the Rose Garden <span class="hlt">vent</span> on the Galapagos Rift</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Clumps of Bathymodiolus thermophilus were collected from three discrete areas at the 'Rose Garden' <span class="hlt">site</span> on the Galapagos Rift using the deep submersible Alvin. Two mussel collections were made from the central Riftia mass, an area associated with very active <span class="hlt">venting</span>, and three other collections were of two different peripheral mussel clumps. Before collection the clumps were extensively photographed and the water at two of the 'microhabitats' was analysed in situ for oxygen silica, sulfide and temperature. Sulfide levels of up to 300 ?M were recorded at the central collection <span class="hlt">site</span>, while the highest sulfide level recorded at the peripheral <span class="hlt">site</span> assayed was 35 ?M. Levels of RuBP carboxylase activity in the gills were significantly higher in mussels collected from the central ' Riftia <span class="hlt">site</span>' than in either peripheral <span class="hlt">site</span>. ATP sulfurylase was significantly higher in the gills of mussels from the central clump than in one of the peripheral clump collections. The chemical composition (% water, protein, carbohydrate, lipid and ash) and stable carbon isotope ratios ( ?13C) of the mussels showed the same trends, with highest lipid and carbohydrate and the lowest water content and ?13C in the central <span class="hlt">site</span> mussels. Similarly, the mussels from the central <span class="hlt">site</span> were significantly depleted in stable nitrogen ( ?15N) when compared with the peripheral <span class="hlt">site</span> mussels. Variations between <span class="hlt">sites</span> and tissues of the same animal may be indicative of differential utilization of inorganic or dissolved molecular nitrogen sources. The condition index (CI = soft tissue dry mass / internal shell volume) was similar for all animals collected at Rose Garden. The presence of a commensal polychaete, Branchipolynoe symmytilida, in the mantle cavity of the mussels was also correlated with the collection <span class="hlt">site</span>, with the highest incidence of occurrence in the central clump. Levels of the enzyme RuBP carboxylase are quite variable in B. thermophilus and are on the average much lower (0.001 international units) than either Calyptogena magnifica (0.006 I.U.) or Riftia pachyptila (0.16 I.U.). We conclude that the mussels are able to thrive over a wider range of conditions than either C. magnifica or R. pachypila and that this is due to a lesser reliance on their symbiotic bacteria as a source of nutrition.</p> <div class="credits"> <p class="dwt_author">Fisher, C. R.; Childress, J. J.; Arp, A. J.; Brooks, J. M.; Distel, D.; Favuzzi, J. A.; Felbeck, H.; Hessler, R.; Johnson, K. S.; Kennicutt, M. C.; Macko, S. A.; Newton, A.; Powell, M. A.; Somero, G. N.; Soto, T.</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-10-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">307</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFMOS52A..05B"> <span id="translatedtitle">Event Detection for <span class="hlt">Hydrothermal</span> Plumes: A case study at Grotto <span class="hlt">Vent</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Evidence is mounting that geologic events such as volcanic eruptions (and intrusions) and earthquakes (near and far) influence the flow rates and temperatures of <span class="hlt">hydrothermal</span> systems. Connecting such suppositions to observations of <span class="hlt">hydrothermal</span> output is challenging, but new ongoing time series have the potential to capture such events. This study explores using activity detection, a technique modified from computer vision, to identify pre-defined events within an extended time series recorded by COVIS (Cabled Observatory <span class="hlt">Vent</span> Imaging Sonar) and applies it to a time series, with gaps, from Sept 2010 to the present; available measurements include plume orientation, plume rise rate, and diffuse flow area at the NEPTUNE Canada Observatory at Grotto <span class="hlt">Vent</span>, Main Endeavour Field, Juan de Fuca Ridge. Activity detection is the process of finding a pattern (activity) in a data set containing many different types of patterns. Among many approaches proposed to model and detect activities, we have chosen a graph-based technique, Petri Nets, as they do not require training data to model the activity. They use the domain expert's knowledge to build the activity as a combination of feature states and their transitions (actions). Starting from a conceptual model of how <span class="hlt">hydrothermal</span> plumes respond to daily tides, we have developed a Petri Net based detection algorithm that identifies deviations from the specified response. Initially we assumed that the orientation of the plume would change smoothly and symmetrically in a consistent daily pattern. However, results indicate that the rate of directional changes varies. The present Petri Net detects unusually large and rapid changes in direction or amount of bending; however inspection of Figure 1 suggests that many of the events detected may be artifacts resulting from gaps in the data or from the large temporal spacing. Still, considerable complexity overlies the "normal" tidal response pattern (the data has a dominant frequency of ~12.9 hours). We are in the process of defining several events of particular scientific interest: 1) transient behavioral changes associated with atmospheric storms, earthquakes or volcanic intrusions or eruptions, 2) mutual interaction of neighboring plumes on each other's behavior, and 3) rapid shifts in plume direction that indicate the presence of unusual currents or changes in currents. We will query the existing data to see if these relationships are ever observed as well as testing our understanding of the "normal" pattern of response to tidal currents.Figure 1. Arrows indicate plume orientation at a given time (time axis in days after 9/29/10) and stars indicate times when orientation changes rapidly.</p> <div class="credits"> <p class="dwt_author">Bemis, K. G.; Ozer, S.; Xu, G.; Rona, P. A.; Silver, D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">308</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008GGG.....9.7022F"> <span id="translatedtitle">Variable morphologic expression of volcanic, tectonic, and <span class="hlt">hydrothermal</span> processes at six <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields in the Lau back-arc basin</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Ultrahigh-resolution bathymetric maps (25 cm grid) are used to quantify the physical dimensions of and spatial relationships between tectonic, volcanic, and <span class="hlt">hydrothermal</span> features at six <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields in the Lau back-arc basin. Supplemented with near-bottom photos, and nested within regional DSL-120A side-scan sonar data, these maps provide insight into the nature of <span class="hlt">hydrothermal</span> systems along the Eastern Lau Spreading Center (ELSC) and Valu Fa Ridge (VFR). Along-axis transitions evident in localized volcanic morphology and tectonic characteristics include a change from broad low-relief volcanic domes (hundreds of meters wide, <10 m tall) that are dominated by pillow and lobate lava morphologies and are cut by faults and fissures to higher aspect ratio volcanic domes (tens of meters wide, tens of meters tall) dominated by aa-type lava morphologies, with finger-like flows, and few tectonic structures. These along-axis differences in localized seafloor morphology suggest differences in <span class="hlt">hydrothermal</span> circulation pathways within the shallow crust and correlate with regional transitions in a variety of ridge properties, including the large-scale morphology of the ridge axis (shallow axial valley to axial high), seafloor lava compositions, and seismic properties of the upper crust. Differences in morphologic characteristics of individual flows and lava types were also quantified, providing an important first step toward the remote characterization of complex terrains associated with <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields.</p> <div class="credits"> <p class="dwt_author">Ferrini, Vicki Lynn; Tivey, Margaret K.; Carbotte, Suzanne M.; Martinez, Fernando; Roman, Chris</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">309</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3703532"> <span id="translatedtitle">Diversity and phylogenetic analyses of bacteria from a shallow-water <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> in Milos island (Greece)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Studies of shallow-water <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> have been lagging behind their deep-sea counterparts. Hence, the importance of these systems and their contribution to the local and regional diversity and biogeochemistry is unclear. This study analyzes the bacterial community along a transect at the shallow-water <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> system of Milos island, Greece. The abundance and biomass of the prokaryotic community is comparable to areas not affected by <span class="hlt">hydrothermal</span> activity and was, on average, 1.34 × 108 cells g?1. The abundance, biomass and diversity of the prokaryotic community increased with the distance from the center of the <span class="hlt">vent</span> and appeared to be controlled by the temperature gradient rather than the trophic conditions. The retrieved 16S rRNA gene fragments matched sequences from a variety of geothermal environments, although the average similarity was low (94%), revealing previously undiscovered taxa. Epsilonproteobacteria constituted the majority of the population along the transect, with an average contribution to the total diversity of 60%. The larger cluster of 16S rRNA gene sequences was related to chemolithoautotrophic Sulfurovum spp., an Epsilonproteobacterium so far detected only at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>. The presence of previously unknown lineages of Epsilonproteobacteria could be related to the abundance of organic matter in these systems, which may support alternative metabolic strategies to chemolithoautotrophy. The relative contribution of Gammaproteobacteria to the Milos microbial community increased along the transect as the distance from the center of the <span class="hlt">vent</span> increased. Further attempts to isolate key species from these ecosystems will be critical to shed light on their evolution and ecology.</p> <div class="credits"> <p class="dwt_author">Giovannelli, Donato; d'Errico, Giuseppe; Manini, Elena; Yakimov, Michail; Vetriani, Costantino</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">310</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=143675"> <span id="translatedtitle">Phylogenetic Diversity of Nitrogenase (nifH) Genes in Deep-Sea and <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Environments of the Juan de Fuca Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The subseafloor microbial habitat associated with typical unsedimented mid-ocean-ridge <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystems may be limited by the availability of fixed nitrogen, inferred by the low ammonium and nitrate concentrations measured in diffuse <span class="hlt">hydrothermal</span> fluid. Dissolved N2 gas, the largest reservoir of nitrogen in the ocean, is abundant in deep-sea and <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fluid. In order to test the hypothesis that biological nitrogen fixation plays an important role in nitrogen cycling in the subseafloor associated with unsedimented <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, degenerate PCR primers were designed to amplify the nitrogenase iron protein gene nifH from <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fluid. A total of 120 nifH sequences were obtained from four samples: a nitrogen-poor diffuse <span class="hlt">vent</span> named marker 33 on Axial Volcano, sampled twice over a period of 1 year as its temperature decreased; a nitrogen-rich diffuse <span class="hlt">vent</span> near Puffer on Endeavour Segment; and deep seawater with no detectable <span class="hlt">hydrothermal</span> plume signal. Subseafloor nifH genes from marker 33 and Puffer are related to anaerobic clostridia and sulfate reducers. Other nifH genes unique to the <span class="hlt">vent</span> samples include proteobacteria and divergent Archaea. All of the nifH genes from the deep-seawater sample are most closely related to the thermophilic, anaerobic archaeon Methanococcus thermolithotrophicus (77 to 83% amino acid similarity). These results provide the first genetic evidence of potential nitrogen fixers in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> environments and indicate that at least two sources contribute to the diverse assemblage of nifH genes detected in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fluid: nifH genes from an anaerobic, hot subseafloor and nifH genes from cold, oxygenated deep seawater.</p> <div class="credits"> <p class="dwt_author">Mehta, Mausmi P.; Butterfield, David A.; Baross, John A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">311</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/15648826"> <span id="translatedtitle">Parasitism in species of Bathymodiolus (Bivalvia: Mytilidae) mussels from deep-sea seep and <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Bivalve species, especially mussels, are biomass dominants in many deep-sea chemosynthetic ecosystems. As in shallow-water environments, parasites are likely to be important factors in the population dynamics of bivalve communities in chemosynthetic ecosystems, but there has been little study of parasitism in deep-sea seep or <span class="hlt">vent</span> molluscs. In this study, parasite types, diversity, prevalence, infection density and non-infectious indicators of stress or disease as related to host age, reproductive condition, and endosymbiont density were assessed in mussels (Bathymodiolus heckerae) from 2 seep <span class="hlt">sites</span> and mussels (B. puteoserpentis) from 2 <span class="hlt">vent</span> <span class="hlt">sites</span>. We identified 10 microbial or parasitic agents in histological sections. Parasite types included 3 viral-like gut inclusions, 2 rickettsia-like gill inclusions, a rickettsia-like mantle inclusion, a bacterial gill-rosette, a chlamydia-like gut inclusion, gill-dwelling ciliates, and an unidentified inclusion in gut tissues. Parasite species richness was greater in seep mussels than in <span class="hlt">vent</span> mussels, with the seep mussels possessing 9 types of parasites compared to 2 in the <span class="hlt">vent</span> mussels. One of the viral-like inclusions infecting the seep mussel B. heckerae was pathogenic, causing lysis of the digestive tubules. The prevalence and intensity of infection by this pathogen were greater in hosts with shell lengths less than 100 mm. Mussels from all 4 <span class="hlt">sites</span> also exhibited intense infiltration of tissues and blood spaces by enlarged hemocytes. Hemocytic infiltration (hemocytosis) showed variable degrees of severity that were not associated with other host factors examined. PMID:15648826</p> <div class="credits"> <p class="dwt_author">Ward, Megan E; Shields, Jeffrey D; Van Dover, Cindy L</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-11-23</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">312</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2005AGUFMOS21C..04G"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> Activity on the Southern Mid-Atlantic Ridge: Tectonically- and Volcanically-Hosted High Temperature <span class="hlt">Venting</span> at 2-7 Degrees S</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We have conducted a systematic investigation for <span class="hlt">hydrothermal</span> activity along the southern Mid-Atlantic Ridge, 2°30-6°50 S. Our initial approach was to use a combination of multi-beam swath mapping, deep-tow sidescan sonar imaging and water column plume-detection using MAPRs and CTD-rosette system to locate new <span class="hlt">sites</span> of <span class="hlt">hydrothermal</span> activity immediately south of the Romanche and Chain Fracture zones. We wanted to test whether these geologic features represent a significant barrier to gene-flow along-axis away from northern MAR <span class="hlt">vent</span> ecosystems. During the first leg of our research cruise (RRS Charles Darwin cruise CD169, Feb-Mar 2005) we used this approach to identify two <span class="hlt">hydrothermally</span> active regions, one in a non-transform discontinuity near 4°S and the other in a segment centre characterised by very fresh sheet-flows near 5°S. During Leg 2 we returned to the second of these areas and deployed ABE, WHOI's autonomous underwater vehicle, in a three-phase strategy to prospect for, locate, and image new <span class="hlt">hydrothermal</span> fields. During Phase 1 two discrete target areas were located ca. 1km apart along strike within the segment centre. During Phase 2 these two areas were each mapped in detail using an SM2000 system while in situ optical back scatter, Eh, temperature, Mn and Fe(II) sensors were used to confirm the interception of buoyant <span class="hlt">hydrothermal</span> plumes rising from the seafloor. Finally we redeployed ABE (Phase 3) to collect photo-mosaics of each of two new <span class="hlt">vent</span>-areas whilst simultaneously sampling their buoyant plumes by CTD-rosette for TDMn, Fe and CH4 analyses.</p> <div class="credits"> <p class="dwt_author">German, C. R.; Parson, L. M.; Murton, B. J.; Bennett, S. A.; Connelly, D. P.; Evans, A. J.; Prien, R. D.; Ramirez-Llodra, E. Z.; Shank, T. M.; Yoerger, D. R.; Jakuba, M.; Bradley, A. M.; Baker, E. T.; Nakamura, K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">313</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003EAEJA.....5507L"> <span id="translatedtitle">Paleomagnetic and Rock Magnetic Investigation of Felsic <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> System in Back-Arc Setting: Preliminary Results from ODP Leg 193 to Eastern Manus Basin, Papua New Guinea</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The PACMANUS <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field in the Eastern Manus back-arc basin, Papua New Guinea, has been considered as a modern-day analog of massive volcanogenic sulfide deposits within felsic volcanic sequence. This <span class="hlt">vent</span> field was drilled during ODP Leg 193 in November-December, 2000. The recovery was generally low due to fragility of rocks. Of the four <span class="hlt">sites</span> that were drilled, three (<span class="hlt">Sites</span> 1188, 1189 and 1191) had sufficient recovery for detailed paleomagnetic and rock magnetic study. <span class="hlt">Site</span> 1188, a low-temperature diffused <span class="hlt">venting</span> region, was drilled to 370 mbsf utilizing a combination of RCB, Hammer Drill, ADCB and casing, and <span class="hlt">Site</span> 1189, a black smoker region, was drilled to a depth of 200 mbsf using RCB. Paleomagnetic analysis shows that recovered rock samples have inclination close to the present-day Earth field. The top 35 m of PACMANUS <span class="hlt">vent</span> field consists of fresh to moderately altered dacite-rhyodacite and exhibits moderately high natural remanent magnetization (< 6 A/m). Although there are small intervals of markedly less intensive alteration, the region below this extrusive layer is largely comprised of pervasively altered rocks with little evidence of sulfide deposit and exhibits as a whole a low magnetization intensity. However, two intervals with high remanent magnetization (> 6 A/m) were recognized below the upper extrusive layer at <span class="hlt">Site</span> 1188 (135-211 mbsf and 280-370 mbsf) and one interval at <span class="hlt">Site</span> 1189 (137-190 mbsf). In particular, the samples between 135-211-mbsf interval at <span class="hlt">Site</span> 1188 have extremely high remanence with intensities ranging up to 300-500 A/m. Although pockets of magnetite are not uncommon in the ancient <span class="hlt">hydrothermal</span> ore bodies, they have seldom been documented in modern-day system, and little is known about the condition that allows the magnetite to form in <span class="hlt">hydrothermal</span> systems. Here I explore two possibilities of magnetite formation and its alignment with the Earth field: one that these magnetites precipitated from magnetite-rich fluid as it cooled from above the Curie temperature (TRM) and the other that magnetization was acquired by the growth of magnetite grains below the Curie temperature (CRM).</p> <div class="credits"> <p class="dwt_author">Lee, S.-M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">314</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002AGUFM.T11C1255H"> <span id="translatedtitle">Multidisciplinary Investigations of the Galápagos Rift, 86°W to 89.5°W: 25th Anniversary of the Discovery of <span class="hlt">Hydrothermal</span> <span class="hlt">Venting</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In May-June, 2002, a multidisciplinary expedition comprised of biologists, chemists, geologists and engineers conducted a field program on the Galápagos Rift between 86°W and 89.5°W. Objectives of the expedition included revisiting the <span class="hlt">site</span> of one of the first-discovered low-temperature <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> at Rose Garden (originally found in 1979), and searching for new low- and high-temperature <span class="hlt">vents</span> along the largely unexplored western portion of the Galápagos Rift to 89.5°W. The field work was funded primarily by NOAA's Ocean Exploration Program with additional support from the National Science Foundation and Woods Hole Oceanographic Institution. A synergistic array of deep-ocean vehicles was used for the exploration program. Alvin and a new digital towed camera were used for making seafloor observations, acquiring digital imagery and collecting samples. An autonomous vehicle ABE (Autonomous Benthic Explorer), which acquired meter-scale bathymetry, near-bottom magnetics and bottom water-properties data, was utilized to explore for active <span class="hlt">hydrothermal</span> <span class="hlt">venting</span>. Water-column vertical casts and tow-yos with a CTD/rosette were used to explore for plumes emanating from high-temperature <span class="hlt">vents</span>. Alvin and ABE were used to explore for the Rose Garden <span class="hlt">vent</span> field near 86°13.5'W. Detailed bottom-water temperature maps and seafloor magnetics data, in conjunction with visual and photographic observations from Alvin and the towed camera, confirmed that the Rose Garden <span class="hlt">vent</span> field and associated animal community no longer exists, and that prolonged high-temperature <span class="hlt">venting</span> appears to never have occurred in this area. However, a new low-temperature <span class="hlt">vent</span> field (which was named Rosebud) was discovered nearby at a depth of 2450 m, and was found to be developing on a fresh-looking sheet flow at a location approximately 200 m northwest of the former Rose Garden area. A second <span class="hlt">site</span> of low-temperature <span class="hlt">hydrothermal</span> activity, at 1670 m, was discovered on a portion of the unexplored rift near 89.5°W. This <span class="hlt">venting</span> is the first discovered along this portion of the Galápagos Rift and it hosts a large vesicomyid (C. magnifica) clam community that covers an approximately 60 m x 60 m area. Throughout the cruise, ABE was used during night operations to provide synoptic micro-bathymetry maps, magnetics data and bottom water properties. Early each morning, these data were processed and then provided to the Alvin observers prior to that same day's dive. ABE data were occasionally combined with, or supplanted by, data from the towed camera or the CTD. A total of 9 Alvin dives, 7 ABE dives, 5 camera tows and 6 CTD tows/casts were conducted. Detailed micro-bathymetric maps and mosaics of the <span class="hlt">vent</span> communities will be presented.</p> <div class="credits"> <p class="dwt_author">Hammond, S. R.; Shank, T. M.; Fornari, D. J.; Yoerger, D. R.; Bradley, A. M.; Scheirer, D. S.; Tivey, M. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">315</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/43375495"> <span id="translatedtitle">LabHorta: a controlled aquarium system for monitoring physiological characteristics of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">LabHorta is a facility composed of laboratories and retrievable deep-sea\\u000a cages created to support and expand the capabilities of research\\u000a cruises. It also enhances the ability to conduct experimental studies\\u000a with organisms from deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and other deep-sea\\u000a environments, while keeping them under controlled conditions of pressure\\u000a and water chemistry. This paper presents a case study with the <span class="hlt">vent</span></p> <div class="credits"> <p class="dwt_author">Ana Colaco; Raul Bettencourt; Valentina Costa; Silvia Lino; Humberto Lopes; Ines Martins; Luis Pires; Catarina Prieto; Ricardo Serrao Santos</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">316</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014DSRI...87...70C"> <span id="translatedtitle">First insights into macro- and meiofaunal colonisation patterns on paired wood/slate substrata at Atlantic deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In 2006, paired wood and slate panels, each equipped with a temperature probe, were deployed on three different localities on and around the Eiffel Tower edifice (Lucky Strike <span class="hlt">vent</span> field, Mid-Atlantic Ridge) within close proximity of visible <span class="hlt">hydrothermal</span> activity. Recovery of these panels took place in 2008. For this two-year deployment period, the composition of colonising organisms (both macro-and meiofauna) was assessed, along with image analyses of the deployment <span class="hlt">sites</span> in 2006 and 2008. Very few significant differences in colonisation between organic (wood) and inorganic (slate) panels were revealed. Rather, the locality of deployment and the local environmental conditions and <span class="hlt">hydrothermal</span> activity were found to influence taxonomic composition. Variability in microhabitat conditions and biological interactions were hypothesised to interact jointly in shaping new faunal communities on the colonisation substrata.</p> <div class="credits"> <p class="dwt_author">Cuvelier, Daphne; Beesau, Julie; Ivanenko, Viatcheslav N.; Zeppilli, Daniela; Sarradin, Pierre-Marie; Sarrazin, Jozée</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">317</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002AGUFM.V72A1303N"> <span id="translatedtitle">Tidal bottom current modulation of chemical environment in the Suiyo <span class="hlt">hydrothermal</span> <span class="hlt">site</span> in the Izu-Ogasawara (Bonin) Arc.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Intense seafloor observatory studies were done at the Suiyo <span class="hlt">hydrothermal</span> <span class="hlt">site</span> in the summer of 2001 and 2002. Deployed instruments on the seafloor were CTD (Idronaut, Ocean Seven 316), Digiquartz precision pressure sensor and its recorder, 3-D acoustic current meters (NOBSKA, MAVS3), high temperature and redox recorders at the <span class="hlt">vents</span>, in-situ laser particle analyzer (Sequoia Scientific, LISST-Deep), methane sensor (CAPSUM METS) with its data logger, etc. The Suiyo Seamount <span class="hlt">hydrothermal</span> <span class="hlt">site</span> is located in the summit caldera of Izu-Ogasawara (Bonin) Arc (1380 m deep, 28.572 N, 140.643 E). The tide is mixed type dominant with semi-diurnal component. There is no tidal components in temperature and redox records neither at high temperature <span class="hlt">vents</span> (300 deg C) nor at low temperature <span class="hlt">vents</span> (less than 200 deg C). Whereas the temperature, redox, methane concentration in the seawater, particle characters measured just above the seafloor had strong semi-diurnal components. The methane concentration varies from several micro mol/litter to several tens of micro mol/litter associated with 200 mV redox change in the central part of the <span class="hlt">hydrothermal</span> <span class="hlt">site</span>. Semi-diurnal strong bottom current over 40 cm/sec appeared several hours after high tides introduced entrainment of ambient waters in the marginal part of <span class="hlt">hydrothermal</span> <span class="hlt">site</span> and accelerated mixing of <span class="hlt">vent</span> water with bottom water in the central part of the <span class="hlt">hydrothermal</span> <span class="hlt">site</span>. This research was funded by the "Archaean Park" Project (International research project on interaction between sub-<span class="hlt">vent</span> biosphere and geo environment funded by Special Coordination Fund of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. The R/V Natsushima cruise with the sub "Shinkai 2000" was a part of the Deep Sea Research project of the Japan Marine Science and Technology Center (JAMSTEC).</p> <div class="credits"> <p class="dwt_author">Nakamura, K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">318</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008AGUFM.B51D0403S"> <span id="translatedtitle">Towards a Genome-Enabled Sensor for In Situ Monitoring of Microbial Communities in <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Fields</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We report the progress towards a genome-enabled instrument to monitor variations in microbial community in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields for long durations. Our long-term goal is to deploy an in situ microarray device embedded in a lab-on-a-chip device. The microarray detects both the 16S rRNA to identify prokaryotic species and cDNA (converted from mRNA) of selected functional genes to understand activities and dynamics of ocean microbial communities. Each automated, self-contained instrument contains a stack of disposable lab-on-a-chip devices. All measurements are performed on individual chips, starting with pumping seawater through on-chip filter to collect microbes, lysing cells to release nucleic acids, and then analyzing their genomic information. To aid the effort of building the first functional microarray, we participated in the TN-221 cruise funded by the National Science Foundation's Ocean Observatories Initiative to map the seafloor in areas of high scientific interest. During the cruise, multiple deep-sea water samples were collected. The microbes were filtered, frozen and shipped to our laboratory for molecular analysis. The DNA was isolated from these samples and a detailed metagenomic analysis is ongoing for samples of one <span class="hlt">site</span> (80 km offshore of Oregon coast, 380 km away from the Axial Seamount <span class="hlt">vent</span> field, and 5 meters above the 780- meter deep seafloor). From the isolated chromosomal DNA the 16S rRNA clone library was constructed and resultant clones were sequenced. Although the fluorescence microscopic analyses showed the density of biomass is relatively low, phylogenetic results suggested high diversity in these microbial communities. In addition, efforts were made to isolate mRNA directly from these deep-sea ocean samples. The information obtained from these analyses will be essential for development of oligonucleotide probes for the microarray device. First two authors contributed equally.</p> <div class="credits"> <p class="dwt_author">Shi, X.; Wu, J.; Gao, W.; Chao, S.; Zhang, W.; Meldrum, D. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">319</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/39682498"> <span id="translatedtitle">Prokaryote Diversity and Virus Abundance in Shallow <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> of the Mediterranean Sea (Panarea Island) and the Pacific Ocean (North Sulawesi-Indonesia)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Despite their ubiquitous distribution in tectonically active coastal zones, shallow water <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> have been less\\u000a investigated than deep-sea <span class="hlt">vents</span>. In the present study, we investigated the role of viral control and fluid emissions on prokaryote\\u000a abundance, diversity, and community structure (total Archaea, total Bacteria, and sulphate-reducing bacteria) in waters and\\u000a sediments surrounding the caldera of four different shallow-water <span class="hlt">hydrothermal</span></p> <div class="credits"> <p class="dwt_author">E. Manini; G. M. Luna; C. Corinaldesi; D. Zeppilli; G. Bortoluzzi; G. Caramanna; F. Raffa; R. Danovaro</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">320</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/39682766"> <span id="translatedtitle">Dominance of Epiphytic Filamentous Thiothrix spp. on an Aquatic Macrophyte in a <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Flume in Sedge Bay, Yellowstone Lake, Wyoming</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Sublacustrine <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, geysers, and fumaroles impart regions of Yellowstone Lake with distinctive chemical compositions\\u000a that generate unique freshwater habitats and support diverse microbial life. Some microbial communities within Sedge Bay manifest\\u000a themselves as accumulations of white-colored films on the surfaces of aquatic macrophytes located within the <span class="hlt">hydrothermal</span>\\u000a flow of <span class="hlt">vents</span>. It was hypothesized that the white films were the</p> <div class="credits"> <p class="dwt_author">Nick R. Konkol; James C. Bruckner; Carmen Aguilar; David Lovalvo; James S. Maki</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_15");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">321</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/49483928"> <span id="translatedtitle">Growth increments and stable isotope variation in shells of the deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> bivalve mollusk Bathymodiolus brevior from the North Fiji Basin, Pacific Ocean</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Bathymodiolus brevior [von Cosel, R., Métivier, B., Hashimoto, J., 1994. Three new species of Bathymodiolus (Bivalvia: Mytilidae) from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> in the Lau Basin and the North Fiji Basin, western Pacific, and the Snake Pit Area, mid-Atlantic ridge. Veliger 37, 374–392] a bivalve mollusk living at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, exhibits daily microgrowth structures in its shell. This interpretation is substantiated</p> <div class="credits"> <p class="dwt_author">Bernd R. Schöne; Olav Giere</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">322</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2007AGUSM.S51B..07K"> <span id="translatedtitle">An example of extruded sandstones resulting from <span class="hlt">hydrothermal</span> <span class="hlt">venting</span> associated with igneous intrusions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The presence of anomalous sands within deep water Palaeogene sediments offshore south east India can be explained by the effects of <span class="hlt">hydrothermal</span> <span class="hlt">venting</span>. The sands are found within a deep marine sequence of pelagic shales, with no obvious lateral sedimentary provenance, they are believed to have been extruded at the sea bed via <span class="hlt">hydrothermal</span> <span class="hlt">venting</span>. Seismic examples along with well data of these unusual phenomena are presented which support this origin for their presence within this pelagic section. The Mannar sub basin, which lies off the south east coast of India, has its origin in Mid Cretaceous rifting. It is one of a series of SW-NE trending rift basins which together are collectively referred to as the Cauvery Basin. Sediments in the syn-rift section are in excess of 3000m are comprised of a series of both continental and marine clastics. Late Cretaceous and early Palaeogene drift sediments are comprised of deep marine pelagic shales. The Period from the Maastrichtian to the Early Eocene was one of limited sediment input into the Mannar basin, resulting from a westward tilt of the Indian plate, a time of widespread deposition on the western margin of the sub continent. Within this predominantly shale prone interval there are encountered isolated sandstone intervals. These sands exhibit unusual petrographic and sedimentary characteristics which indicate that they have been transported relatively short distances and not long distance from the shelf edge which in this basin may have been several hundred kilometres to the North and West. Along the entire margin of western and south eastern India there is widespread evidence of igneous activity, the most notable being the Deccan Traps of Central and Western India. This igneous activity has been dated from Late Cretaceous up to Early Eocene. The igneous activity in the Mannar basin is postulated to be Eocene in age. In the Mannar Sub basin the igneous activity can be recognised on 3D seismic data and exhibits the increasingly familiar geometries seen in other similar settings such as the NW margin of the European plate. Within the area being presented one particularly well imaged igneous complex is observed beneath an anomalous high amplitude set of seismic reflections which are interpreted to be extruded clastic sediments, brought to the sea bed be as a result of <span class="hlt">hydrothermal</span> <span class="hlt">venting</span>, triggered by the igneous intrusions. Two wells have been drilled which penetrated intervals with similar seismic responses to those illustrated. These wells penetrated sands with very high GR readings and cores taken in the wells indicate that they are debris flows with many typical debris flow characteristics such as fluid escape features. The lateral extent and thickness of the extruded section can cover several square kilometres and range in thickness up to 50m. These dimensions indicate that these "extrudites" could well be of economic importance as hydrocarbon bearing reservoirs</p> <div class="credits"> <p class="dwt_author">King, S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">323</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004AGUFM.B12B..01Z"> <span id="translatedtitle">Carbon-Isotope Fractionations of Autotrophic Bacteria: Relevance to Primary Production and Microbial Evolution in Hot Springs and <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Terrestrial hot springs and marine <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> are often dominated by autotrophic microorganisms. Species of the Bacteria Domain in these environments are known to use different pathways for CO2 fixation. These may include the Calvin cycle, the Acetyl CoA pathway, the reverse TCA cycle, and the 3-HP pathway. Each cycle or pathway may be characterized by distinct patterns of carbon isotope fractionation. This presentation will summarize isotope fractionation patterns associated with known autotrophic bacteria and to use these patterns for interpreting natural isotopic variations. Examples will include hot springs from the Yellowstone National Park and Nevada desert, USA and Kamchatka, Russia, and <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> from the East Pacific Rise. An attempt will be made to discuss isotopic variations within a particular pathway in the context of species evolution through horizontal gene transfer.</p> <div class="credits"> <p class="dwt_author">Zhang, C. L.; Romanek, C. S.; Mills, G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">324</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3017555"> <span id="translatedtitle">Pathways of Carbon and Energy Metabolism of the Epibiotic Community Associated with the Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Shrimp Rimicaris exoculata</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Background The shrimp Rimicaris exoculata dominates the faunal biomass at many deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> at the Mid-Atlantic Ridge. In its enlarged gill chamber it harbors a specialized epibiotic bacterial community for which a nutritional role has been proposed. Methodology/Principal Findings We analyzed specimens from the Snake Pit <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field on the Mid-Atlantic Ridge by complementing a 16S rRNA gene survey with the analysis of genes involved in carbon, sulfur and hydrogen metabolism. In addition to Epsilon- and Gammaproteobacteria, the epibiotic community unexpectedly also consists of Deltaproteobacteria of a single phylotype, closely related to the genus Desulfocapsa. The association of these phylogenetic groups with the shrimp was confirmed by fluorescence in situ hybridization. Based on functional gene analyses, we hypothesize that the Gamma- and Epsilonproteobacteria are capable of autotrophic growth by oxidizing reduced sulfur compounds, and that the Deltaproteobacteria are also involved in sulfur metabolism. In addition, the detection of proteobacterial hydrogenases indicates the potential for hydrogen oxidation in these communities. Interestingly, the frequency of these phylotypes in 16S rRNA gene clone libraries from the mouthparts differ from that of the inner lining of the gill chamber, indicating potential functional compartmentalization. Conclusions Our data show the specific association of autotrophic bacteria with Rimicaris exoculata from the Snake Pit <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field, and suggest that autotrophic carbon fixation is contributing to the productivity of the epibiotic community with the reductive tricarboxylic acid cycle as one important carbon fixation pathway. This has not been considered in previous studies of carbon fixation and stable carbon isotope composition of the shrimp and its epibionts. Furthermore, the co-occurrence of sulfur-oxidizing and sulfur-reducing epibionts raises the possibility that both may be involved in the syntrophic exchange of sulfur compounds, which could increase the overall efficiency of this epibiotic community.</p> <div class="credits"> <p class="dwt_author">Hugler, Michael; Petersen, Jillian M.; Dubilier, Nicole; Imhoff, Johannes F.; Sievert, Stefan M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">325</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40667035"> <span id="translatedtitle">Radiometric dating of sediment cores from a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> zone off Milos Island in the Aegean Sea</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Sediment cores from a <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> zone off Milos Island in the Aegean Sea were dated using the 210Pb method. The average unsupported 210Pb inventory in the cores was calculated to be 3256 Bq m?2. The corresponding mean annual 210Pb flux of 105 Bq m?2 year?1 is comparable to estimates of the atmospheric flux given in the literature. 210Pb fluxes</p> <div class="credits"> <p class="dwt_author">Aysun Ugur; Juan-Carlos Miquel; Scott W. Fowler; Peter Appleby</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">326</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/36341459"> <span id="translatedtitle">Structural Comparison of Cuticle and Interstitial Collagens from Annelids Living in Shallow Seawater and at Deep-sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Two types of annelid collagens of different sizes were purified, one from acetic acid extracts of the cuticle (length 2.5 ?m) and the other, after pepsin digestion, from interstitial spaces of the body wall (0.3 ?m). They were obtained fromAlvinella pompejana, Alvinella caudataandParalvinella grassleicollected at 2600 m depth around anoxic <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and fromArenicola marinaandNereis diversicolorliving in shallow sea-water habitats.</p> <div class="credits"> <p class="dwt_author">Francoise Gaill; Karlheinz Mann; Hanna Wiedemann; Jürgen Engel; Rupert Timpl</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">327</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/34951122"> <span id="translatedtitle">Possible role of a taurine transporter in the deep-sea mussel Bathymodiolus septemdierum in adaptation to <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Various invertebrates inhabiting <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> possess sulfur-oxidizing bacteria in their tissues; however, the mechanisms by which toxic sulfides are delivered to these endosymbionts remain unknown. Recently, detoxification of sulfides using thiotaurine, a sulfur-containing amino acid, has been suggested. In this study, we propose the involvement of a taurine transporter in sulfide detoxification in the deep-sea mussel Bathymodiolus septemdierum by demonstrating:</p> <div class="credits"> <p class="dwt_author">Koji Inoue; Kimihiko Tsukuda; Tomoko Koito; Yoshiko Miyazaki; Masatomi Hosoi; Ryusuke Kado; Nobuyuki Miyazaki; Haruhiko Toyohara</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">328</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/35603793"> <span id="translatedtitle">CHH family peptides from an ‘eyeless’ deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp, Rimicaris kairei: Characterization and sequence analysis</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The crustacean eyestalk synthesizes and secretes several structurally-related peptides belonging to the crustacean hyperglycemic hormone (CHH) family, which are considered major physiological regulators during the crustacean life cycle. However, it is intriguing that eyestalks of many <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> crustaceans prove to have varying degrees of reduction. In the present study, we characterized full-length cDNAs encoding two important eyestalk hormones of</p> <div class="credits"> <p class="dwt_author">Ye-Qing Qian; Li Dai; Jin-Shu Yang; Fan Yang; Dian-Fu Chen; Yoshihiro Fujiwara; Shinji Tsuchida; Hiromichi Nagasawa; Wei-Jun Yang</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">329</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/48394181"> <span id="translatedtitle">Characterization of 15 polymorphic microsatellite loci in Rimicaris exoculata , and cross-amplification in other <span class="hlt">hydrothermal-vent</span> shrimp</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Rimicaris exoculata is an alvinocarid shrimp endemic to the <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> of the Mid-Atlantic Ridge. In order to study genetic variability\\u000a and connectivity in this species, we developed fifteen polymorphic microsatellite markers. The markers were tested on one\\u000a population and, except for one, all showed no departure from Hardy–Weinberg equilibrium, with an average overall observed\\u000a heterozygosity of 0.63. Two primer</p> <div class="credits"> <p class="dwt_author">Sara Teixeira; Ester A. Serrão; Sophie Arnaud-Haond</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">330</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/34390794"> <span id="translatedtitle">A Novel, Highly Viscous Polysaccharide Excreted by an Alteromonas Isolated from a Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Shrimp</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">A deep-sea, mesophilic, aerobic, and heterotrophic microorganism, able to produce an extracellular polysaccharide, was isolated\\u000a from a shrimp collected near an active <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> of the Mid-Atlantic Ridge. On the basis of phenotypic and phylogenetic\\u000a analyses and DNA\\/DNA relatedness, this strain could be assigned to the species Alteromonas macleodii as a variant of the fijiensis subspecies. It was selected for</p> <div class="credits"> <p class="dwt_author">Gérard Raguénès; Marie Anne Cambon-Bonavita; Jean François Lohier; Claire Boisset; Jean Guezennec</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">331</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/36460198"> <span id="translatedtitle">Miocene Radiation of Deep-Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Shrimp (Caridea: Bresiliidae): Evidence from Mitochondrial Cytochrome Oxidase Subunit I</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The evolutionary history of deep-sea shrimp (Caridea: Bresiliidae) inhabiting deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> and hydrocarbon seep environments was assessed using the mitochondrial Cytochrome c Oxidase subunit I (COI) gene (600 bp). Phylogenetic analyses (parsimony, likelihood, and neighbor-joining) recovered three distinct clades (A, Rimicaris\\/Chorocaris\\/Opaepele; B, Alvinocaris; and C, Mirocaris) consistent with higher level taxonomy based on morphology. However, robust phylogenetic results suggested</p> <div class="credits"> <p class="dwt_author">Timothy M. Shank; Michael B. Black; Kenneth M. Halanych; Richard A. Lutz; Robert C. Vrijenhoek</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">332</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/r74t60nt47832l26.pdf"> <span id="translatedtitle">Specific effects of thiosulphate and L-lactate on hemocyanin-O 2 affinity in a brachyuran <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> crab</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> crab Bythograea thermydron Williams (Brachyura: Bythograeidae) is exposed to high environmental concentrations of hydrogen sulphide. Hydrogen sulphide has previously been shown to be oxidized to a non-toxic form, thiosulphate (S2O32-), that accumulates in the hemolymph (to concentrations>1 mmoll-1). Hemocyanin-oxygen (Hc-O2) affinity was determined in dialysed, fresh or frozen hemolymph samples from B. thermydron. Although freezing is known</p> <div class="credits"> <p class="dwt_author">N. K. Sanders; J. J. Childress</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">333</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.sb-roscoff.fr/Ecchis/pdf/07-Brand-MarEcol.pdf"> <span id="translatedtitle">Hypotaurine and thiotaurine as indicators of sulfide exposure in bivalves and vestimentiferans from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and cold seeps</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Vesicomyid clams, vestimentiferans, and some bathymodiolin mussels from <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> and cold seeps possess thiotrophic endosymbionts, high levels of hypotaurine and, in tissues with symbionts, thiotaurine. The latter, a product of hypotaurine and sulfide, may store and\\/or transport sulfide non-toxically, and the ratio to hypotaurine plus thiotaurine (Th\\/(H+Th)) may reflect an animal's sulfide exposure. To test this, we analyzed seep</p> <div class="credits"> <p class="dwt_author">Garth L. Brand; Robin V. Horak; Nadine Le Bris; Shana K. Goffredi; Susan L. Carney; Breea Govenar; Paul H. Yancey</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">334</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/38612877"> <span id="translatedtitle">Molecular identification of differentially regulated genes in the <span class="hlt">hydrothermal-vent</span> species Bathymodiolus thermophilus and Paralvinella pandorae in response to temperature</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">BACKGROUND: <span class="hlt">Hydrothermal</span> <span class="hlt">vents</span> and cold seeps represent oases of life in the deep-sea environment, but are also characterized by challenging physical and chemical conditions. The effect of temperature fluctuations on <span class="hlt">vent</span> organisms in their habitat has not been well explored, in particular at a molecular level, most gene expression studies being conducted on coastal marine species. In order to better</p> <div class="credits"> <p class="dwt_author">Isabelle Boutet; Didier Jollivet; Bruce Shillito; Dario Moraga; Arnaud Tanguy</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">335</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://gump.auburn.edu/halanych/lab/Pub.pdfs/Hunt2004.pdf"> <span id="translatedtitle">Testing biological control of colonization by vestimentiferan tubeworms at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> (East Pacific Rise, 9°50?N)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Three species of vestimentiferans are found at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> on the East Pacific Rise (EPR). Tevnia jerichonana is an early colonist and Riftia pachyptila has the greatest biomass in established <span class="hlt">vent</span> assemblages, but the role of Oasisia alvinae, a small species that occurs sporadically, is unknown. Anecdotal evidence suggests that O. alvinae may be abundant in the microhabitat underneath mussels.</p> <div class="credits"> <p class="dwt_author">Heather L. Hunt; Anna Metaxas; Robert M. Jennings; Kenneth M. Halanych; Lauren S. Mullineaux</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">336</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/d85v1266w766qn39.pdf"> <span id="translatedtitle">POM in macro-\\/meiofaunal food webs associated with three flow regimes at deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> on Axial Volcano, Juan de Fuca Ridge</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> ecosystems host both symbiotic and non-symbiotic invertebrates. The non-symbiotic <span class="hlt">vent</span> fauna is\\u000a generally assumed to rely on free-living chemoautotrophic bacteria as their main food source but other sources such as detritus\\u000a have recently been suggested to be a part of the invertebrate diets. Little is known about how food availability influences\\u000a the distribution of <span class="hlt">vent</span> organisms on</p> <div class="credits"> <p class="dwt_author">Helene Limén; Christian Levesque; S. Kim Juniper</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">337</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2001E%26PSL.193..381D"> <span id="translatedtitle">Hot <span class="hlt">vents</span> in an ice-cold ocean: Indications for phase separation at the southernmost area of <span class="hlt">hydrothermal</span> activity, Bransfield Strait, Antarctica</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">During the expeditions ANT-XV/2 with R/V Polarstern in 1997/98 and NBP 99-04 with R/V IB N.B. Palmer in 1999, the first samples of <span class="hlt">hydrothermally</span> influenced sediments of Bransfield Strait were obtained at Hook Ridge, a volcanic edifice in the Central Basin of the Strait. The <span class="hlt">vent</span> <span class="hlt">sites</span> are characterized by white siliceous crusts on top of the sediment layer and temperatures measured immediately on deck are up to 48.5°C. The shallow depth of these <span class="hlt">vent</span> <span class="hlt">sites</span> (1050 m) particularly controls the chemistry of the pore fluids that are enriched in silica and sulfide and show low pH values. Chloride is depleted up to 20% and the calculated <span class="hlt">hydrothermal</span> endmember concentration is in the range of 1-84 mM. Since other mechanisms for Cl depletion can be ruled out clearly, the composition of this fluid is attributed to phase separation. While the Cl-depleted fluid is emanating at Hook Ridge, a Cl-enriched fluid can be identified in the adjacent King George Basin. Using a p,x diagram the two corresponding endmember concentrations reveal that the phase separation takes place at subcritical conditions (total depth: ˜2500 m), probably along the whole volcanic edifice.</p> <div class="credits"> <p class="dwt_author">Dählmann, A.; Wallmann, K.; Sahling, H.; Sarthou, G.; Bohrmann, G.; Petersen, S.; Chin, C. S.; Klinkhammer, G. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">338</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/21877264"> <span id="translatedtitle">Molecular biomineralization: toward an understanding of the biogenic origin of polymetallic nodules, seamount crusts, and <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Polymetallic nodules and crusts, <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> from the Deep Sea are economically interesting, since they contain alloying components, e.g., manganese or cobalt, that are used in the production of special steels; in addition, they contain rare metals applied for plasma screens, for magnets in hard disks, or in hybrid car motors. While <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> can regenerate in weeks, polymetallic nodules and seamount crusts grow slowly. Even though the geochemical basis for the growth of the nodules and crusts has been well studied, the contribution of microorganisms to the formation of these minerals remained obscure. Recent HR-SEM (high-resolution scanning electron microscopy) analyses of nodules and crusts support their biogenic origin. Within the nodules, bacteria with surface S-layers are arranged on biofilm-like structures, around which Mn deposition starts. In crusts, coccoliths represent the dominant biologically formed structures that act as bio-seeds for an initial Mn deposition. In contrast, <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> have apparently an abiogenic origin; however, their minerals are biogenically transformed by bacteria. In turn, strategies can now be developed for biotechnological enrichment as well as selective dissolution of metals from such concretions. We are convinced that the recent discoveries will considerably contribute to our understanding of the participation of organic matrices in the enrichment of those metals and will provide the basis for feasibility studies for biotechnological applications. PMID:21877264</p> <div class="credits"> <p class="dwt_author">Wang, Xiaohong; Wiens, Matthias; Schröder, Heinz C; Schloßmacher, Ute; Müller, Werner E G</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">339</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/12467117"> <span id="translatedtitle">Nitrogen reduction under <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> conditions: implications for the prebiotic synthesis of C-H-O-N compounds.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Dinitrogen is reduced in dilute hydrogen sulfide (H2S) solutions to ammonium at 120 degrees C. Experiments with dissolved dinitrogen (partial pressure 50 bar) in a 12 x 10(-3) mol/L H2S(aq) solution yield approximately 10(-5) mol/L NH4+ within 2-7 days. These yields are consistent with the equilibrium NH4+ concentration for the N-S-H system under these conditions. The formation of ammonium is catalyzed by the presence of freshly precipitated iron monosulfide. These results indicate that dinitrogen can be reduced at moderate temperatures in <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> systems. Abiotic nitrogen reduction could have taken place within primordial <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, supplying some ammonia for the synthesis of C-H-O-N compounds via abiotic processes. The yield of ammonia via dinitrogen reduction by hydrogen sulfide, however, is so low that it is doubtful this process could have produced enough ammonia to sustain prebiotic <span class="hlt">hydrothermal</span> synthesis of C-H-O-N compounds in or around <span class="hlt">vent</span> systems. PMID:12467117</p> <div class="credits"> <p class="dwt_author">Schoonen, M A; Xu, Y</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">340</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=168656"> <span id="translatedtitle">A histidine protein kinase homolog from the endosymbiont of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> tubeworm Riftia pachyptila.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The uncultivated bacterial endosymbionts of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> tubeworm Riftia pachyptila play a central role in providing their host with fixed carbon. While this intimate association between host and symbiont indicates tight integration and coordination of function via cellular communication mechanisms, no such systems have been identified. To elucidate potential signal transduction pathways in symbionts that may mediate symbiont-host communication, we cloned and characterized a gene encoding a histidine protein kinase homolog isolated from a symbiont fosmid library. The gene, designated rssA (for Riftia symbiont signal kinase), resembles known sensor kinases and encodes a protein capable of phosphorylating response regulators in Escherichia coli. A second open reading frame, rssB (for Riftia symbiont signal regulator), encodes a protein similar to known response regulators. These results suggest that the symbionts utilize a phosphotransfer signal transduction mechanism to communicate external signals that may mediate recognition of or survival within the host. The specific signals eliciting a response by the signal transduction proteins of the symbiont remain to be elucidated.</p> <div class="credits"> <p class="dwt_author">Hughes, D S; Felbeck, H; Stein, J L</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_16");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a 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showDiv("page_19");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">341</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1389137"> <span id="translatedtitle">Molecular Identification and Localization of Filamentous Symbiotic Bacteria Associated with the <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> Annelid Alvinella pompejana</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Alvinella pompejana is a polychaetous annelid that inhabits high-temperature environments associated with active deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> along the East Pacific Rise. A unique and diverse epibiotic microflora with a prominent filamentous morphotype is found associated with the worm's dorsal integument. A previous study established the taxonomic positions of two epsilon proteobacterial phylotypes, 13B and 5A, which dominated a clone library of 16S rRNA genes amplified by PCR from the epibiotic microbial community of an A. pompejana specimen. In the present study deoxyoligonucleotide PCR primers specific for phylotypes 13B and 5A were used to demonstrate that these phylotypes are regular features of the bacterial community associated with A. pompejana. Assaying of other surfaces around colonies of A. pompejana revealed that phylotypes 13B and 5A are not restricted to A. pompejana. Phylotype 13B occurs on the exterior surfaces of other invertebrate genera and rock surfaces, and phylotype 5A occurs on a congener, Alvinella caudata. The 13B and 5A phylotypes were identified and localized on A. pompejana by in situ hybridization, demonstrating that these two phylotypes are, in fact, the prominent filamentous bacteria on the dorsal integument of A. pompejana. These findings indicate that the filamentous bacterial symbionts of A. pompejana are epsilon Proteobacteria which do not have an obligate requirement for A. pompejana.</p> <div class="credits"> <p class="dwt_author">Cary, S. C.; Cottrell, M. T.; Stein, J. L.; Camacho, F.; Desbruyeres, D.</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">342</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008BGD.....5.1825C"> <span id="translatedtitle">Iron oxide deposits associated with the ectosymbiotic bacteria in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp Rimicaris exoculata</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Rimicaris exoculata shrimp is considered a primary consumer that dominates the fauna of most Mid-Atlantic Ridge (MAR) <span class="hlt">hydrothermal</span> ecosystems. These shrimps harbour in their gill chambers an important ectosymbiotic community of chemoautotrophic bacteria associated with iron oxide deposits. The structure and elemental composition of the minerals associated with these bacteria have been investigated by using X-ray microanalyses, light microscopy, and transmission, environmental scanning and scanning transmission electron microscopy. The nature of the iron oxides in shrimps obtained from the Rainbow <span class="hlt">vent</span> field at 36°14.0' N, has also been determined by Mössbauer spectroscopy. This multidisciplinary approach has revealed that the three step-levels of mineral crust found in the Rimicaris exoculata shrimps consist of heavy concretions formed by nanoparticles of two-line ferrihydrite intermixed with minor inorganic SiO2, (Ca,Mg)SO4, and (Ca,Mg)3(PO4)2 minerals that may stabilise the ferrihydrite form of iron oxides. Morphological observations on the bacteria have revealed their close interactions with these minerals and, thus, indicate the biogenic origin of the iron oxide deposits. The evolution of the bacterial density in the three mineral crust levels is related to the amount of the iron deposits and it is proposed that the lower crust level is the most likely region for the location of the iron-oxidizing bacteria.</p> <div class="credits"> <p class="dwt_author">Corbari, L.; Cambon-Bonavita, M.-A.; Long, G. J.; Grandjean, F.; Zbinden, M.; Gaill, F.; Compère, P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-04-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">343</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008BGeo....5.1295C"> <span id="translatedtitle">Iron oxide deposits associated with the ectosymbiotic bacteria in the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> shrimp Rimicaris exoculata</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Rimicaris exoculata shrimp is considered as a primary consumer that dominates the fauna of most Mid-Atlantic Ridge (MAR) <span class="hlt">hydrothermal</span> ecosystems. These shrimps harbour in their gill chambers an important ectosymbiotic community of chemoautotrophic bacteria associated with iron oxide deposits. The structure and elemental composition of the mineral concretions associated with these bacteria have been investigated by using LM, ESEM, TEM STEM and EDX microanalyses. The nature of the iron oxides in shrimps obtained from the Rainbow <span class="hlt">vent</span> field has also been determined by Mössbauer spectroscopy. This multidisciplinary approach has revealed that the three layers of mineral crust in the Rimicaris exoculata shrimps consist of large concretions formed by aggregated nanoparticles of two-line ferrihydrite and include other minor elements as Si, Ca, Mg, S and P, probably present as silicates cations, sulphates or phosphates respectively that may contribute to stabilise the ferrihydrite form of iron oxides. TEM-observations on the bacteria have revealed their close interactions with these minerals. Abiotic and biotic precipitation could occur within the gill chamber of Rimicaris exoculata, suggesting the biologically-mediated formation of the iron oxide deposits. The difference of the bacterial density in the three-mineral crust layers could be correlated to the importance of the iron oxide concretions and suggest that the first mineral particles precipitates on the lower layer which could be considered as the most likely location of iron-oxidizing bacteria.</p> <div class="credits"> <p class="dwt_author">Corbari, L.; Cambon-Bonavita, M.-A.; Long, G. J.; Grandjean, F.; Zbinden, M.; Gaill, F.; Compère, P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">344</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3695450"> <span id="translatedtitle">Identity and mechanisms of alkane-oxidizing metalloenzymes from deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Six aerobic alkanotrophs (organism that can metabolize alkanes as their sole carbon source) isolated from deep-sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> were characterized using the radical clock substrate norcarane to determine the metalloenzyme and reaction mechanism used to oxidize alkanes. The organisms studied were Alcanivorax sp. strains EPR7 and MAR14, Marinobacter sp. strain EPR21, Nocardioides sp. strains EPR26w, EPR28w, and Parvibaculum hydrocarbonoclasticum strain EPR92. Each organism was able to grow on n-alkanes as the sole carbon source and therefore must express genes encoding an alkane-oxidizing enzyme. Results from the oxidation of the radical-clock diagnostic substrate norcarane demonstrated that five of the six organisms (EPR7, MAR14, EPR21, EPR26w, and EPR28w) used an alkane hydroxylase functionally similar to AlkB to catalyze the oxidation of medium-chain alkanes, while the sixth organism (EPR92) used an alkane-oxidizing cytochrome P450 (CYP)-like protein to catalyze the oxidation. DNA sequencing indicated that EPR7 and EPR21 possess genes encoding AlkB proteins, while sequencing results from EPR92 confirmed the presence of a gene encoding CYP-like alkane hydroxylase, consistent with the results from the norcarane experiments.</p> <div class="credits"> <p class="dwt_author">Bertrand, Erin M.; Keddis, Ramaydalis; Groves, John T.; Vetriani, Costantino; Austin, Rachel Narehood</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">345</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/21673885"> <span id="translatedtitle">The biological deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> as a model to study carbon dioxide capturing enzymes.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> are located along the mid-ocean ridge system, near volcanically active areas, where tectonic plates are moving away from each other. Sea water penetrates the fissures of the volcanic bed and is heated by magma. This heated sea water rises to the surface dissolving large amounts of minerals which provide a source of energy and nutrients to chemoautotrophic organisms. Although this environment is characterized by extreme conditions (high temperature, high pressure, chemical toxicity, acidic pH and absence of photosynthesis) a diversity of microorganisms and many animal species are specially adapted to this hostile environment. These organisms have developed a very efficient metabolism for the assimilation of inorganic CO? from the external environment. In order to develop technology for the capture of carbon dioxide to reduce greenhouse gases in the atmosphere, enzymes involved in CO? fixation and assimilation might be very useful. This review describes some current research concerning CO? fixation and assimilation in the deep sea environment and possible biotechnological application of enzymes for carbon dioxide capture. PMID:21673885</p> <div class="credits"> <p class="dwt_author">Minic, Zoran; Thongbam, Premila D</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">346</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3111178"> <span id="translatedtitle">The Biological Deep Sea <span class="hlt">Hydrothermal</span> <span class="hlt">Vent</span> as a Model to Study Carbon Dioxide Capturing Enzymes</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Deep sea <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> are located along the mid-ocean ridge system, near volcanically active areas, where tectonic plates are moving away from each other. Sea water penetrates the fissures of the volcanic bed and is heated by magma. This heated sea water rises to the surface dissolving large amounts of minerals which provide a source of energy and nutrients to chemoautotrophic organisms. Although this environment is characterized by extreme conditions (high temperature, high pressure, chemical toxicity, acidic pH and absence of photosynthesis) a diversity of microorganisms and many animal species are specially adapted to this hostile environment. These organisms have developed a very efficient metabolism for the assimilation of inorganic CO2 from the external environment. In order to develop technology for the capture of carbon dioxide to reduce greenhouse gases in the atmosphere, enzymes involved in CO2 fixation and assimilation might be very useful. This review describes some current research concerning CO2 fixation and assimilation in the deep sea environment and possible biotechnological application of enzymes for carbon dioxide capture.</p> <div class="credits"> <p class="dwt_author">Minic, Zoran; Thongbam, Premila D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">347</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/6190639"> <span id="translatedtitle">Temporal variation in the antioxidant defence system and lipid peroxidation in the gills and mantle of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> mussel Bathymodiolus azoricus</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Hydrothermal</span> <span class="hlt">vent</span> mussels are exposed continually to toxic compounds, including high metal concentrations and other substances like dissolved sulphide, methane and natural radioactivity. Fluctuations in these parameters appear to be common because of the characteristic instability of the <span class="hlt">hydrothermal</span> environment. Temporal variation in the antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), total glutathione peroxidases (Total GPx), selenium dependent glutathione peroxidases</p> <div class="credits"> <p class="dwt_author">Angela Serafim; Richard Cosson; Aline Fiala-Médioni; David Dixon; Maria João Bebianno</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">348</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3741630"> <span id="translatedtitle">New insights into <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> processes in the unique shallow-submarine arc-volcano, Kolumbo (Santorini), Greece</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">We report on integrated geomorphological, mineralogical, geochemical and biological investigations of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field located on the floor of the density-stratified acidic (pH ~ 5) crater of the Kolumbo shallow-submarine arc-volcano, near Santorini. Kolumbo features rare geodynamic setting at convergent boundaries, where arc-volcanism and seafloor <span class="hlt">hydrothermal</span> activity are occurring in thinned continental crust. Special focus is given to unique enrichments of polymetallic spires in Sb and Tl (±Hg, As, Au, Ag, Zn) indicating a new hybrid seafloor analogue of epithermal-to-volcanic-hosted-massive-sulphide deposits. Iron microbial-mat analyses reveal dominating ferrihydrite-type phases, and high-proportion of microbial sequences akin to "Nitrosopumilus maritimus", a mesophilic Thaumarchaeota strain capable of chemoautotrophic growth on <span class="hlt">hydrothermal</span> ammonia and CO2. Our findings highlight that acidic shallow-submarine <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> nourish marine ecosystems in which nitrifying Archaea are important and suggest ferrihydrite-type Fe3+-(hydrated)-oxyhydroxides in associated low-temperature iron mats are formed by anaerobic Fe2+-oxidation, dependent on microbially produced nitrate.</p> <div class="credits"> <p class="dwt_author">Kilias, Stephanos P.; Nomikou, Paraskevi; Papanikolaou, Dimitrios; Polymenakou, Paraskevi N.; Godelitsas, Athanasios; Argyraki, Ariadne; Carey, Steven; Gamaletsos, Platon; Mertzimekis, Theo J.; Stathopoulou, Eleni; Goettlicher, Joerg; Steininger, Ralph; Betzelou, Konstantina; Livanos, Isidoros; Christakis, Christos; Bell, Katherine Croff; Scoullos, Michael</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">349</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23939372"> <span id="translatedtitle">New insights into <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> processes in the unique shallow-submarine arc-volcano, Kolumbo (Santorini), Greece.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">We report on integrated geomorphological, mineralogical, geochemical and biological investigations of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> field located on the floor of the density-stratified acidic (pH ~ 5) crater of the Kolumbo shallow-submarine arc-volcano, near Santorini. Kolumbo features rare geodynamic setting at convergent boundaries, where arc-volcanism and seafloor <span class="hlt">hydrothermal</span> activity are occurring in thinned continental crust. Special focus is given to unique enrichments of polymetallic spires in Sb and Tl (±Hg, As, Au, Ag, Zn) indicating a new hybrid seafloor analogue of epithermal-to-volcanic-hosted-massive-sulphide deposits. Iron microbial-mat analyses reveal dominating ferrihydrite-type phases, and high-proportion of microbial sequences akin to "Nitrosopumilus maritimus", a mesophilic Thaumarchaeota strain capable of chemoautotrophic growth on <span class="hlt">hydrothermal</span> ammonia and CO2. Our findings highlight that acidic shallow-submarine <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> nourish marine ecosystems in which nitrifying Archaea are important and suggest ferrihydrite-type Fe(3+)-(hydrated)-oxyhydroxides in associated low-temperature iron mats are formed by anaerobic Fe(2+)-oxidation, dependent on microbially produced nitrate. PMID:23939372</p> <div class="credits"> <p class="dwt_author">Kilias, Stephanos P; Nomikou, Paraskevi; Papanikolaou, Dimitrios; Polymenakou, Paraskevi N; Godelitsas, Athanasios; Argyraki, Ariadne; Carey, Steven; Gamaletsos, Platon; Mertzimekis, Theo J; Stathopoulou, Eleni; Goettlicher, Joerg; Steininger, Ralph; Betzelou, Konstantina; Livanos, Isidoros; Christakis, Christos; Bell, Katherine Croff; Scoullos, Michael</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">350</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=123976"> <span id="translatedtitle">Neutrophilic Fe-Oxidizing Bacteria Are Abundant at the Loihi Seamount <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> and Play a Major Role in Fe Oxide Deposition</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">A number of <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> <span class="hlt">sites</span> exist on the summit of the Loihi Seamount, a shield volcano that is part of the Hawaiian archipelago. The <span class="hlt">vents</span> are 1,100 to 1,325 m below the surface and range in temperature from slightly above ambient (10°C) to high temperature (167°C). The <span class="hlt">vent</span> fluid is characterized by high concentrations of CO2 (up to 17 mM) and Fe(II) (up to 268 ?M), but there is a general paucity of H2S. Most of the <span class="hlt">vents</span> are surrounded by microbial mats that have a gelatinous texture and are heavily encrusted with rust-colored Fe oxides. Visually, the Fe oxides appeared homogeneous. However, light microscopy revealed that the oxides had different morphologies, which fell into three classes: (i) sheaths, (ii) twisted or irregular filaments, and (iii) amorphous oxides. A morphological analysis of eight different samples indicated that the amorphous oxides were overall the most abundant; however, five <span class="hlt">sites</span> had >50% sheaths and filamentous oxides. These latter morphologies are most likely the direct result of microbial deposition. Direct cell counts revealed that all of the oxides had abundant microbial populations associated with them, from 6.9 × 107 to 5.3 × 108 cells per ml of mat material. At most <span class="hlt">sites</span>, end point dilution series for lithotrophic Fe oxidizers were successful out to dilutions of 10?6 and 10?7. A pure culture was obtained from a 10?7 dilution tube; this strain, JV-1, was an obligate, microaerophilic Fe oxidizer that grew at 25 to 30°C. A non-cultivation-based molecular approach with terminal-restriction fragment length polymorphism also indicated the common presence of Fe-oxidizing bacteria at Loihi. Together, these results indicate that Fe-oxidizing bacteria are common at the Loihi Seamount and probably play a major role in Fe oxidation. A review of the literature suggests that microbially mediated Fe oxidation at <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> may be important globally.</p> <div class="credits"> <p class="dwt_author">Emerson, David; Moyer, Craig L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">351</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1995DSRI...42..577H"> <span id="translatedtitle">Microdistribution pattern and biogeography of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> communities of the Minami-Ensei Knoll in the mid-Okinawa trough, Western Pacific</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">From 1988 to 1992, a series of deep-sea surveys was conducted to characterize <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> fields on the Minami-Ensei Knoll, approximately 140 km west of Amami-Ohshima Island, southwest Japan, with a multi-narrow beam mapping system (Sea Beam), deep tow observing systems and the submersible Shinkai 2000. The <span class="hlt">vent</span> fields were centered around the depressions on the western slope of the knoll. The <span class="hlt">hydrothermal</span> <span class="hlt">vents</span> emitted superheated water over 269°C through chimneys. Diffuse fluid discharged from fissures in rocks. Numerous patches of grayish white <span class="hlt">hydrothermal</span> stains were observed on the bottom of coarse sand. <span class="hlt">Vent</span>-associated biological communities consisted of sponges, vestimentiferans, alvinellid and polynoid polychaetes, cerithiid and trochid gastropods, lepetrodrillid limpets, vesicomyid clams, mytilid bivalves, bresiliid and hippolytid shrimp, zoarcid and cynoglossid fish, and lithodid and galatheid crabs. The <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> communities of the Minami-Ensei Knoll showed many similarities to those of the Kaikata Seamount, the Mariana Back-Arc Spreading Center, the North Fiji Basin and the Lau Basin, as well as the cold seep communities of Sagami Bay. There may be considerable interchange among the Minami-Ensei knoll communities and other chemosynthetic communities in the Western Pacific despite the 1000 km distance separating these communities and the existence of Ryukyu Trench and Ryukyu Arc. These discoveries, as well as other more recent findings around Japan, contribute significantly to our understanding of the biogeography of the <span class="hlt">hydrothermal</span> <span class="hlt">vent</span> and cold seep communities in the Western Pacific.</p> <div class="credits"> <p class="dwt_author">Hashimoto, Jun; Ohta, Suguru; Fujikura, Katsunori; Miura, Tomoyuki</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">352</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2000E%26PSL.177...89G"> <span id="translatedtitle">Non-transform offsets along the Mid-Atlantic Ridge south of the Azores (38°N-34°N): ultramafic exposures and hosting of <span class="hlt">hydrothermal</span> <span class="hlt">vents</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Ten contiguous non-transform offsets (NTOs) along the Mid-Atlantic Ridge (MAR) south of the Azores (between 38°N and 35°40'N) have been studied in detail using swath bathymetric, acoustic backscatter and deep-tow high-resolution sidescan sonar (TOBI) data. In contrast with discontinuities studied elsewhere at slow-spreading ridges, these left-lateral NTOs are consistently broader and larger, with complex structural fabrics accommodating the offset. They are characterized by a range of elevated and faulted massifs detached from their segment flanks, with an irregular acoustic backscatter pattern. Some of these massifs have been explored and sampled recently during dive cruises revealing that they are composed of upper mantle peridotites and lower crustal rocks, and sometimes associated with high-temperature <span class="hlt">hydrothermal</span> <span class="hlt">venting</span>. Water column surveys adjacent to these massifs show high CH 4 and low TDM (total dissolvable manganese) concentrations, possibly resulting from the process of serpentinization of ultramafic rocks. The correlation between the shallow dome-like shaped massifs and the high concentrations of CH 4 (associated with low levels of Mn) is of particular interest to predict the outcrop of ultramafic rocks within the NTOs where no geological data are available. The exposure of the ultramafic massifs within the NTOs is favored by low magmatic supply and low-angle detachment faulting occurring at segment ends. The pervasive fracturing and faulting at these discontinuities favor circulation of <span class="hlt">hydrothermal</span> fluids and occurrence of high-temperature <span class="hlt">vent</span> <span class="hlt">sites</span>.</p> <div class="credits"> <p class="dwt_author">Gràcia, Eulàlia; Charlou, Jean Luc; Radford-Knoery, Joël; Parson, Lindsay M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-04-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">353</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=124112"> <span id="translatedtitle">Isolation of Tellurite- and Selenite-Resistant Bacteria from <span class="hlt">Hydrothermal</span> <span class="hlt">Vents</span> of the Juan de Fuca Ridge in the Pacific Ocean</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Deep-ocean <span class="hlt">hydrothermal-vent</span> environments are rich in heavy metals and metalloids and present excellent <span class="hlt">sites</span> for the isolation of metal-resistant microorganisms. Both metalloid-oxide-resistant and metalloid-oxide-reducing bacteria were found. Tellurite- and selenite-reducing strains were isolated in high numbers from ocean water near <span class="hlt">hydrothermal</span> <span class="hlt">vents</span>, bacterial films, and sulfide-rich rocks. Growth of these isolates in media containing K2TeO3 or Na2SeO3 resulted in the accumulation of metallic tellurium or selenium. The MIC of K2TeO3 ranged from 1,500 to greater than 2,500 ?g/ml, and the MIC of Na2SeO3 ranged from 6,000 to greater than 7,000 ?g/ml for 10 strains. Phylogenetic analysis of 4 of these 10 strains revealed that they form a branch closely related to members of the genus Pseudoalteromonas, within the ?-3 subclass of the Proteobacteria. All 10 strains were found to be salt tolerant, pH tolerant, and thermotolerant. The metalloid resistance and morphological, physiological, and phylogenetic characteristics of newly isolated strains are described.</p> <div class="credits"> <p class="dwt_author">Rathgeber, Christopher; Yurkova, Natalia; Stackebrandt, Erko; Beatty, J. Thomas; Yurkov, Vladimir</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">354</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFMOS22B..03G"> <span id="translatedtitle"><span class="hlt">Hydrothermal</span> Activity on the Mid-Cayman Rise: ROV Jason sampling and <span class="hlt">site</span> characterization at the Von Damm and Piccard <span class="hlt">hydrothermal</span> fields</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In January 2012 our multi-national and multi-disciplinary team conducted a series of 10 ROV Jason dives to conduct first detailed and systematic sampling of the Mid Cayman Rise <span class="hlt">hydrothermal</span> systems at the Von Damm and Piccard <span class="hlt">hydrothermal</span> fields. At Von Damm, <span class="hlt">hydrothermal</span> <span class="hlt">venting</span> is focused at and around a large conical structure that is approximately 120 m in diameter and rises at least 80m from the surrounding, largely sedimented seafloor. Clear fluids emitted from multiple <span class="hlt">sites</span> around the flanks of the mound fall in the temperature range 110-130°C and fall on a common mixing line with hotter (>200°C) clear fluids emitted from an 8m tall spire at the summit which show clear evidence of ultramafic influence. Outcrop close to the <span class="hlt">vent-site</span> is rare and the cone itself appear to consist of clay minerals derived from highly altered host rock. The dominant fauna at the summit of Von Damm are a new species of chemosynthetic shrimp but elsewhere the <span class="hlt">site</span> also hosts two distinct species of chemosynthetic tube worm as well as at least one species of gastropod. The adjacent Piccard <span class="hlt">site</span>, at ~5000m depth comprises 7 distinct sulfide mounds, 3 of which are currently active: Beebe <span class="hlt">Vents</span>, Beebe Woods and Beebe Sea. Beebe <span class="hlt">Vents</span> consists of 5 vigorous black smoker chimneys with maximum temperatures in the range 400-403°C while at Beebe Woods a more highly colonized thicket of up to 8m tall chimneys includes predominantly beehive diffusers with rare black smokers emitting fluids up to 353°C. Beebe Sea a diffuse <span class="hlt">site</span> emitting fluids at 38°C Tmax, is the largest of the currently active mounds and immediately abuts a tall (8m) rift that strikes NE-SW bisecting the host Axial Volcanic Ridge. The fauna at Piccard are less diverse than at Von Damm and, predominantly, comprise the same species of MCR shrimp, a distinct gastropod species and abundant anemones.</p> <div class="credits"> <p class="dwt_author">German, C. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">355</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.ht