Science.gov

Sample records for deep sea multi-locus

  1. Deep sea waste disposal

    SciTech Connect

    Kester, D.R.; Burt, W.V.; Capuzzo, J.M.; Park, P.K.; Ketchum, B.W.; Duedall, I.W.

    1985-01-01

    The book presents papers on the marine disposal of wastes. Topics considered include incineration at sea, the modelling and biological effects of industrial wastes, microbial studies of ocean dumping, deep-sea mining wastes, the chemical analysis of ferromanganese nodules, and economic aspects of deep-sea disposal.

  2. A Deep-Sea Simulation.

    ERIC Educational Resources Information Center

    Montes, Georgia E.

    1997-01-01

    Describes an activity that simulates exploration techniques used in deep-sea explorations and teaches students how this technology can be used to take a closer look inside volcanoes, inspect hazardous waste sites such as nuclear reactors, and explore other environments dangerous to humans. (DDR)

  3. Ploughing the deep sea floor.

    PubMed

    Puig, Pere; Canals, Miquel; Company, Joan B; Martín, Jacobo; Amblas, David; Lastras, Galderic; Palanques, Albert

    2012-09-13

    Bottom trawling is a non-selective commercial fishing technique whereby heavy nets and gear are pulled along the sea floor. The direct impact of this technique on fish populations and benthic communities has received much attention, but trawling can also modify the physical properties of seafloor sediments, water–sediment chemical exchanges and sediment fluxes. Most of the studies addressing the physical disturbances of trawl gear on the seabed have been undertaken in coastal and shelf environments, however, where the capacity of trawling to modify the seafloor morphology coexists with high-energy natural processes driving sediment erosion, transport and deposition. Here we show that on upper continental slopes, the reworking of the deep sea floor by trawling gradually modifies the shape of the submarine landscape over large spatial scales. We found that trawling-induced sediment displacement and removal from fishing grounds causes the morphology of the deep sea floor to become smoother over time, reducing its original complexity as shown by high-resolution seafloor relief maps. Our results suggest that in recent decades, following the industrialization of fishing fleets, bottom trawling has become an important driver of deep seascape evolution. Given the global dimension of this type of fishery, we anticipate that the morphology of the upper continental slope in many parts of the world’s oceans could be altered by intensive bottom trawling, producing comparable effects on the deep sea floor to those generated by agricultural ploughing on land.

  4. Deep-sea soundings

    NASA Astrophysics Data System (ADS)

    Brooks, David A.

    Bathymetric charts for many areas of the ocean are cheap and accurate, and we usually take their availability for granted. In these times of abundant information, it is easy to forget the wonder and excitement of the last century, when mechanical sounding machines revealed for the first time the major features of the ocean depths. Who would not be awed by the graceful sweep of the Blake Plateau or the plunging depths of the Puerto Rico Trench, and who could remain unimpressed by undersea mountain ranges more majestic than any in view? In his 1888 book, entitled Three Cruises of the Blake, Alexander Agassiz has this to say about the spectacular Caribbean bottom topography: “Compared to such panoramas the finest views of the range of the Alps sink into insignificance; it is only when we get a view of portions of the Andes from the sea-coast…that we get anything approximating to it in grandeur.”

  5. Biogeography of Persephonella in deep-sea hydrothermal vents of the Western Pacific.

    PubMed

    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

    2013-01-01

    Deep-sea hydrothermal vent 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 vents. Although this group of bacteria has cosmopolitan distribution in deep-sea hydrothermal 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 hydrothermal vent bacteria.

  6. Biogeography of Persephonella in deep-sea hydrothermal vents of the Western Pacific

    PubMed Central

    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

    2013-01-01

    Deep-sea hydrothermal vent 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 vents. Although this group of bacteria has cosmopolitan distribution in deep-sea hydrothermal 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 hydrothermal vent bacteria. PMID:23630523

  7. Advanced deep sea diving equipment

    NASA Technical Reports Server (NTRS)

    Danesi, W. A.

    1972-01-01

    Design requirements are generated for a deep sea heavy duty diving system to equip salvage divers with equipment and tools that permit work of the same quality and in times approaching that done on the surface. The system consists of a helmet, a recirculator for removing carbon dioxide, and the diver's dress. The diver controls the inlet flow by the recirculatory control valve and is able to change closed cycle operation to open cycle if malfunction occurs. Proper function of the scrubber in the recirculator minimizes temperature and humidity effects as it filters the returning air.

  8. Microplastic pollution in deep-sea sediments.

    PubMed

    Van Cauwenberghe, Lisbeth; Vanreusel, Ann; Mees, Jan; Janssen, Colin R

    2013-11-01

    Microplastics are small plastic particles (<1 mm) originating from the degradation of larger plastic debris. These microplastics have been accumulating in the marine environment for decades and have been detected throughout the water column and in sublittoral and beach sediments worldwide. However, up to now, it has never been established whether microplastic presence in sediments is limited to accumulation hot spots such as the continental shelf, or whether they are also present in deep-sea sediments. Here we show, for the first time ever, that microplastics have indeed reached the most remote of marine environments: the deep sea. We found plastic particles sized in the micrometre range in deep-sea sediments collected at four locations representing different deep-sea habitats ranging in depth from 1100 to 5000 m. Our results demonstrate that microplastic pollution has spread throughout the world's seas and oceans, into the remote and largely unknown deep sea.

  9. Temperature Impacts on Deep-Sea Biodiversity

    NASA Astrophysics Data System (ADS)

    Yasuhara, M.; Danovaro, R.

    2015-12-01

    Temperature is considered to be a fundamental factor controlling biodiversity in marine ecosystems, but precisely what role temperature plays in modulating diversity is still not clear. The deep ocean, lacking light and in situ photosynthetic primary production, is an ideal model system to test the effects of temperature changes on biodiversity. Here we synthesize current knowledge on temperature-diversity relationships in the deep sea. Our results from both present and past deep-sea assemblages suggest that, when a wide range of deep-sea bottom-water temperatures is considered, a unimodal relationship exists between temperature and diversity (that may be right skewed). It is possible that temperature is important only when at relatively high and low levels but does not play a major role in the intermediate temperature range. Possible mechanisms explaining the temperature-biodiversity relationship include the physiological-tolerance hypothesis, the metabolic hypothesis, island biogeography theory, or some combination of these. The possible unimodal relationship discussed here may allow us to identify tipping points at which on-going global change and deep-water warming may increase or decrease deep-sea biodiversity. Predicted changes in deep-sea temperatures due to human-induced climate change may have more adverse consequences than expected considering the sensitivity of deep-sea ecosystems to temperature changes.

  10. Temperature impacts on deep-sea biodiversity.

    PubMed

    Yasuhara, Moriaki; Danovaro, Roberto

    2016-05-01

    Temperature is considered to be a fundamental factor controlling biodiversity in marine ecosystems, but precisely what role temperature plays in modulating diversity is still not clear. The deep ocean, lacking light and in situ photosynthetic primary production, is an ideal model system to test the effects of temperature changes on biodiversity. Here we synthesize current knowledge on temperature-diversity relationships in the deep sea. Our results from both present and past deep-sea assemblages suggest that, when a wide range of deep-sea bottom-water temperatures is considered, a unimodal relationship exists between temperature and diversity (that may be right skewed). It is possible that temperature is important only when at relatively high and low levels but does not play a major role in the intermediate temperature range. Possible mechanisms explaining the temperature-biodiversity relationship include the physiological-tolerance hypothesis, the metabolic hypothesis, island biogeography theory, or some combination of these. The possible unimodal relationship discussed here may allow us to identify tipping points at which on-going global change and deep-water warming may increase or decrease deep-sea biodiversity. Predicted changes in deep-sea temperatures due to human-induced climate change may have more adverse consequences than expected considering the sensitivity of deep-sea ecosystems to temperature changes.

  11. Population structure of deep-sea chemolithoautotrophs: identification of phenotypic and genotypic correlations

    NASA Astrophysics Data System (ADS)

    Mino, S.; Nakagawa, S.; Sawabe, T.; Miyazaki, J.; Makita, H.; Nunoura, T.; Yamamoto, M.; Takai, K.

    2012-12-01

    Deep-sea hydrothermal fields are areas on the seafloor of high biological productivity fueled primarily by microbial chemosynthesis. Chemolithoautotrophic Epsilonproteobacteria and Persephonella with an ability to utilize inorganic substrates such as elemental sulfur and hydrogen are important members in wide range of temperature conditions in deep-sea hydrothermal vents. However, little is known about their population genetic structure such as intraspecific genetic diversity, distribution pattern, and phenotypic characteristics. Previously, using genetic approach based on multi-locus sequence analysis (MLSA), we clarified that Epsilonproteobacteria Group A, B, F, and Persephonella populations were geographically separated, and Epsilonproteobacteria appeared to diverge by mutation rather than recombination. Contrary to genetic evidence for allopatric segregation in deep-sea chemoautotrophs, however, phenotypic evidence has never been found. In addition, analyzing such a phenotypic characteristic may lead to a better understanding of the interactions microbes have with their environment. In this study, we present a metabolomic approach based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) to reveal phenotypic biogeographical discrimination. We demonstrated the whole-cell MALDI-TOF MS method on Epsilonproteobacteria and Persephonella populations. These chemoautotrophic strains used in this study were isolated from chimney structures, vent fluids, and hydrothermal sediments. These hydrothermal samples were collected from geographically separated hydrothermal areas of the South Mariana Trough, Okinawa Trough and Central Indian Ridge. Based on mass peaks (signal/noise >10) within the m/z range of 2000-14000, phenotypic analysis was carried out by cluster analysis. The result of phenotypic analysis was compared with the genotypic clusters. The whole-cell MALDI-TOF MS revealed that Persephonella population was identified to

  12. The South China Sea Deep: Introduction

    NASA Astrophysics Data System (ADS)

    Wang, Pinxian; Li, Qianyu; Dai, Minhan

    2015-12-01

    The South China Sea (SCS) has increasingly become a global focus in ocean research and hydrocarbon explorations. Over the last two decades, at least 17 international cruises including two ODP/IODP expeditions were conducted in the SCS, and more than 2000 exploratory wells were drilled (Wang et al., 2014a). While its sedimentary basins on the continental shelf and slope are explored for offshore resources, the deep basin below 3500 m in depth that overlies the basaltic oceanic crust preserves the key to understanding their formation and development. In order to better understand the life history and functional system of the marginal sea, a major research program "Deep Sea Processes and Evolution of the South China Sea", or "The South China Sea Deep" for short, was launched in January 2011 by the National Natural Science Foundation (NSFC) of China. This venture represents the first ever large-scale basic-research program in ocean science in the country (Wang, 2012).

  13. 47 CFR 32.2424 - Submarine & deep sea cable.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic...

  14. 47 CFR 32.2424 - Submarine & deep sea cable.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic...

  15. 47 CFR 32.2424 - Submarine & deep sea cable.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic...

  16. 47 CFR 32.2424 - Submarine & deep sea cable.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic...

  17. 47 CFR 32.2424 - Submarine & deep sea cable.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic...

  18. Measurement of light scattering in deep sea

    NASA Astrophysics Data System (ADS)

    Maragos, N.; Balasi, K.; Domvoglou, T.; Kiskiras, I.; Lenis, D.; Maniatis, M.; Stavropoulos, G.

    2016-04-01

    The deep-sea neutrino telescope in the Mediterranean Sea, being prepared by the KM3NET collaboration, will contain thousands of optical sensors to readout. The accurate knowledge of the optical properties of deep-sea water is of great importance for the neutrino event reconstruction process. In this study we describe our progress in designing an experimental setup and studying a method to measure the parameters describing the absorption and scattering characteristics of deep-sea water. Three PMTs will be used to measure in situ the scattered light emitted from six laser diodes in three different wavelengths covering the Cherenkov radiation spectrum. The technique for the evaluation of the parameters is based on Monte Carlo simulations and our results show that we are able to determine these parameters with satisfying precision.

  19. Colonization of the deep sea by fishes

    PubMed Central

    Priede, I G; Froese, R

    2013-01-01

    Analysis of maximum depth of occurrence of 11 952 marine fish species shows a global decrease in species number (N) with depth (x; m): log10N = −0·000422x + 3·610000 (r2 = 0·948). The rate of decrease is close to global estimates for change in pelagic and benthic biomass with depth (−0·000430), indicating that species richness of fishes may be limited by food energy availability in the deep sea. The slopes for the Classes Myxini (−0·000488) and Actinopterygii (−0·000413) follow this trend but Chondrichthyes decrease more rapidly (−0·000731) implying deficiency in ability to colonize the deep sea. Maximum depths attained are 2743, 4156 and 8370 m for Myxini, Chondrichthyes and Actinopterygii, respectively. Endemic species occur in abundance at 7–7800 m depth in hadal trenches but appear to be absent from the deepest parts of the oceans, >9000 m deep. There have been six global oceanic anoxic events (OAE) since the origin of the major fish taxa in the Devonian c. 400 million years ago (mya). Colonization of the deep sea has taken place largely since the most recent OAE in the Cretaceous 94 mya when the Atlantic Ocean opened up. Patterns of global oceanic circulation oxygenating the deep ocean basins became established coinciding with a period of teleost diversification and appearance of the Acanthopterygii. Within the Actinopterygii, there is a trend for greater invasion of the deep sea by the lower taxa in accordance with the Andriashev paradigm. Here, 31 deep-sea families of Actinopterygii were identified with mean maximum depth >1000 m and with >10 species. Those with most of their constituent species living shallower than 1000 m are proposed as invasive, with extinctions in the deep being continuously balanced by export of species from shallow seas. Specialized families with most species deeper than 1000 m are termed deep-sea endemics in this study; these appear to persist in the deep by virtue of global distribution enabling

  20. Colonization of the deep sea by fishes.

    PubMed

    Priede, I G; Froese, R

    2013-12-01

    Analysis of maximum depth of occurrence of 11 952 marine fish species shows a global decrease in species number (N) with depth (x; m): log10 N = -0·000422x + 3·610000 (r(2)  = 0·948). The rate of decrease is close to global estimates for change in pelagic and benthic biomass with depth (-0·000430), indicating that species richness of fishes may be limited by food energy availability in the deep sea. The slopes for the Classes Myxini (-0·000488) and Actinopterygii (-0·000413) follow this trend but Chondrichthyes decrease more rapidly (-0·000731) implying deficiency in ability to colonize the deep sea. Maximum depths attained are 2743, 4156 and 8370 m for Myxini, Chondrichthyes and Actinopterygii, respectively. Endemic species occur in abundance at 7-7800 m depth in hadal trenches but appear to be absent from the deepest parts of the oceans, >9000 m deep. There have been six global oceanic anoxic events (OAE) since the origin of the major fish taxa in the Devonian c. 400 million years ago (mya). Colonization of the deep sea has taken place largely since the most recent OAE in the Cretaceous 94 mya when the Atlantic Ocean opened up. Patterns of global oceanic circulation oxygenating the deep ocean basins became established coinciding with a period of teleost diversification and appearance of the Acanthopterygii. Within the Actinopterygii, there is a trend for greater invasion of the deep sea by the lower taxa in accordance with the Andriashev paradigm. Here, 31 deep-sea families of Actinopterygii were identified with mean maximum depth >1000 m and with >10 species. Those with most of their constituent species living shallower than 1000 m are proposed as invasive, with extinctions in the deep being continuously balanced by export of species from shallow seas. Specialized families with most species deeper than 1000 m are termed deep-sea endemics in this study; these appear to persist in the deep by virtue of global distribution enabling recovery

  1. Climate Influence on Deep Sea Populations

    PubMed Central

    Company, Joan B.; Puig, Pere; Sardà, Francesc; Palanques, Albert; Latasa, Mikel; Scharek, Renate

    2008-01-01

    Dynamics of biological processes on the deep-sea floor are traditionally thought to be controlled by vertical sinking of particles from the euphotic zone at a seasonal scale. However, little is known about the influence of lateral particle transport from continental margins to deep-sea ecosystems. To address this question, we report here how the formation of dense shelf waters and their subsequent downslope cascade, a climate induced phenomenon, affects the population of the deep-sea shrimp Aristeus antennatus. We found evidence that strong currents associated with intense cascading events correlates with the disappearance of this species from its fishing grounds, producing a temporary fishery collapse. Despite this initial negative effect, landings increase between 3 and 5 years after these major events, preceded by an increase of juveniles. The transport of particulate organic matter associated with cascading appears to enhance the recruitment of this deep-sea living resource, apparently mitigating the general trend of overexploitation. Because cascade of dense water from continental shelves is a global phenomenon, we anticipate that its influence on deep-sea ecosystems and fisheries worldwide should be larger than previously thought. PMID:18197243

  2. Climate influence on deep sea populations.

    PubMed

    Company, Joan B; Puig, Pere; Sardà, Francesc; Palanques, Albert; Latasa, Mikel; Scharek, Renate

    2008-01-16

    Dynamics of biological processes on the deep-sea floor are traditionally thought to be controlled by vertical sinking of particles from the euphotic zone at a seasonal scale. However, little is known about the influence of lateral particle transport from continental margins to deep-sea ecosystems. To address this question, we report here how the formation of dense shelf waters and their subsequent downslope cascade, a climate induced phenomenon, affects the population of the deep-sea shrimp Aristeus antennatus. We found evidence that strong currents associated with intense cascading events correlates with the disappearance of this species from its fishing grounds, producing a temporary fishery collapse. Despite this initial negative effect, landings increase between 3 and 5 years after these major events, preceded by an increase of juveniles. The transport of particulate organic matter associated with cascading appears to enhance the recruitment of this deep-sea living resource, apparently mitigating the general trend of overexploitation. Because cascade of dense water from continental shelves is a global phenomenon, we anticipate that its influence on deep-sea ecosystems and fisheries worldwide should be larger than previously thought.

  3. Deep Circulation in the South China Sea

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaolong; Zhao, Wei; Xu, Xiaobiao; Tian, Jiwei; Zhou, Chun

    2016-04-01

    The South China Sea (SCS) is the largest marginal sea of the northwest Pacific. The deep circulation in the SCS is investigated on the basis of the Hybrid Coordinate Ocean Model (HYCOM). All the experiments show reasonable agreement with observation from mooring arrays. Analysis of these results provides a detailed spatial structure and temporal variability of the deep circulation in the SCS. The major features of the SCS deep circulation are basin-scale cyclonic gyre and concentrated deep western boundary current (DWBC). The transport of the DWBC is ~2 Sv at 16.5°N with a width of ~53 km. As flowing southwestward, the DWBC becomes weaker with a wider range. Deep upwelling in the SCS is estimated of 0.19 to 1.15 m d-1 with the strongest area around the DWBC. The model results reveal the existence of 80 to 120 days oscillation in the deep northeastern circulation and the DWBC, which are also the areas with large eddy kinetic energy. This seasonal oscillation is northwestward with a velocity amplitude of ~1.0~1.5 cm s-1. The distribution of mixing parameters in the deep SCS plays a role in both spatial structure and volume transport of the deep circulation. Compared with the north shelf of the SCS with the Luzon Strait, deep circulation in the SCS is more sensitive to the large vertical mixing parameters of the Zhongsha Island Chain area.

  4. In Brief: Deep-sea observatory

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2008-11-01

    The first deep-sea ocean observatory offshore of the continental United States has begun operating in the waters off central California. The remotely operated Monterey Accelerated Research System (MARS) will allow scientists to monitor the deep sea continuously. Among the first devices to be hooked up to the observatory are instruments to monitor earthquakes, videotape deep-sea animals, and study the effects of acidification on seafloor animals. ``Some day we may look back at the first packets of data streaming in from the MARS observatory as the equivalent of those first words spoken by Alexander Graham Bell: `Watson, come here, I need you!','' commented Marcia McNutt, president and CEO of the Monterey Bay Aquarium Research Institute, which coordinated construction of the observatory. For more information, see http://www.mbari.org/news/news_releases/2008/mars-live/mars-live.html.

  5. Deep-sea Hexactinellida (Porifera) of the Weddell Sea

    NASA Astrophysics Data System (ADS)

    Janussen, Dorte; Tabachnick, Konstantin R.; Tendal, Ole S.

    2004-07-01

    New Hexactinellida from the deep Weddel Sea are described. This moderately diverse hexactinellid fauna includes 14 species belonging to 12 genera, of which five species and one subgenus are new to science: Periphragella antarctica n. sp., Holascus pseudostellatus n. sp., Caulophacus (Caulophacus) discohexactinus n. sp., C. ( Caulodiscus) brandti n. sp., C. ( Oxydiscus) weddelli n. sp., and C. ( Oxydiscus) n. subgen. So far, 20 hexactinellid species have been reported from the deep Weddell Sea, 15 are known from the northern part and 10 only from here, while 10 came from the southern area, and five of these only from there. However, this apparent high "endemism" of Antarctic hexactinellid sponges is most likely the result of severe undersampling of the deep-sea fauna. We find no reason to believe that a division between an oceanic and a more continental group of species exists. The current poor database indicates that a substantial part of the deep hexactinellid fauna of the Weddell Sea is shared with other deep-sea regions, but it does not indicate a special biogeographic relationship with any other ocean.

  6. Autonomous, Retrievable, Deep Sea Microbial Fuel Cell

    NASA Astrophysics Data System (ADS)

    Richter, K.

    2014-12-01

    Microbial fuel cells (MFCs) work by providing bacteria in anaerobic sediments with an electron acceptor (anode) that stimulates metabolism of organic matter. The buried anode is connected via control circuitry to a cathode exposed to oxygen in the overlying water. During metabolism, bacteria release hydrogen ions into the sediment and transfer electrons extra-cellularly to the anode, which eventually reduce dissolved oxygen at the cathode, forming water. The open circuit voltage is approximately 0.8 v. The voltage between electrodes is operationally kept at 0.4 v with a potentiastat. The current is chiefly limited by the rate of microbial metabolism at the anode. The Office of Naval Research has encouraged development of microbial fuel cells in the marine environment at a number of academic and naval institutions. Earlier work in shallow sediments of San Diego Bay showed that the most important environmental parameters that control fuel cell power output in San Diego Bay were total organic carbon in the sediment and seasonal water temperature. Current MFC work at SPAWAR includes extension of microbial fuel cell tests to the deep sea environment (>1000 m) and, in parallel, testing microbial fuel cells in the laboratory under deep sea conditions. One question we are asking is whether MFC power output from deep water sediments repressurized and chilled in the laboratory comparable to those measured in situ. If yes, mapping the power potential of deep sea sediments may be made much easier, requiring sediment grabs and lab tests rather than deployment and retrieval of fuel cells. Another question we are asking is whether in situ temperature and total organic carbon in the deep sea sediment can predict MFC power. If yes, then we can make use of the large collection of publicly available, deep sea oceanographic measurements to make these predictions, foregoing expensive work at sea. These regressions will be compared to those derived from shallow water measurements.

  7. The study of deep-sea cephalopods.

    PubMed

    Hoving, Henk-Jan T; Perez, Jose Angel A; Bolstad, Kathrin S R; Braid, Heather E; Evans, Aaron B; Fuchs, Dirk; Judkins, Heather; Kelly, Jesse T; Marian, José E A R; Nakajima, Ryuta; Piatkowski, Uwe; Reid, Amanda; Vecchione, Michael; Xavier, José C C

    2014-01-01

    "Deep-sea" cephalopods are here defined as cephalopods that spend a significant part of their life cycles outside the euphotic zone. In this chapter, the state of knowledge in several aspects of deep-sea cephalopod research are summarized, including information sources for these animals, diversity and general biogeography and life cycles, including reproduction. Recommendations are made for addressing some of the remaining knowledge deficiencies using a variety of traditional and more recently developed methods. The types of oceanic gear that are suitable for collecting cephalopod specimens and images are reviewed. Many groups of deep-sea cephalopods require taxonomic reviews, ideally based on both morphological and molecular characters. Museum collections play a vital role in these revisions, and novel (molecular) techniques may facilitate new use of old museum specimens. Fundamental life-cycle parameters remain unknown for many species; techniques developed for neritic species that could potentially be applied to deep-sea cephalopods are discussed. Reproductive tactics and strategies in deep-sea cephalopods are very diverse and call for comparative evolutionary and experimental studies, but even in the twenty-first century, mature individuals are still unknown for many species. New insights into diet and trophic position have begun to reveal a more diverse range of feeding strategies than the typically voracious predatory lifestyle known for many cephalopods. Regular standardized deep-sea cephalopod surveys are necessary to provide insight into temporal changes in oceanic cephalopod populations and to forecast, verify and monitor the impacts of global marine changes and human impacts on these populations.

  8. Mass extinctions in the deep sea

    NASA Technical Reports Server (NTRS)

    Thomas, E.

    1988-01-01

    The character of mass extinctions can be assessed by studying extinction patterns of organisms, the fabric of the extinction, and assessing the environmental niche and mode of life of survivors. Deep-sea benthic foraminifera have been listed as little affected by the Cretaceous-Tertiary (K-T) mass extinction, but very few quantitative data are available. New data on deep-sea Late Maestrichtian-Eocene benthic foraminifera from Maud Rise (Antractica) indicate that about 10 percent of the species living at depths of 2000 to 2500 m had last appearances within 1 my of the Cretaceous-Tertiary (K-T) boundary, versus about 25 percent of species at 1000 to 1500 m. Many survivors from the Cretaceous became extinct in a period of global deep-sea benthic foraminiferal extinction at the end of the Paleocene, a time otherwise marked by very few extinctions. Preliminary conclusions suggest that the deep oceanic environment is essentially decoupled from the shallow marine and terrestrial environment, and that even major disturbances of one of these will not greatly affect the other. This gives deep-sea benthic faunas a good opportunity to recolonize shallow environments from greater depths and vice versa after massive extinctions. The decoupling means that data on deep-sea benthic boundary was caused by the environmental effects of asteriod impact or excessive volcanism. The benthic foraminiferal data strongly suggest, however, that the environmental results were strongest at the Earth's surface, and that there was no major disturbance of the deep ocean; this pattern might result both from excessive volcanism and from an impact on land.

  9. Experimental investigation of deep sea riser interaction

    SciTech Connect

    Huse, E.

    1996-12-31

    In future deep sea field developments the drag force and corresponding static deflections of the risers due to current can become quite large. The prevention of mechanical contact (collision) between the risers will need more careful evaluation than in moderate water depths. The paper describes a series of model experiments in a Norwegian fjord to determine criteria for on-set of collisions between the risers of a deep sea TLP. The current was modeled using the natural tidal current in the fjord. Results from the tests are summarized and used for verification of numerical calculations of collision criteria.

  10. Deep sea tides determination from GEOS-3

    NASA Technical Reports Server (NTRS)

    Maul, G. A.; Yanaway, A.

    1978-01-01

    GEOS 3 altimeter data in a 5 degree X 5 degree square centered at 30 deg N, 70 deg W were analyzed to evaluate deep sea tide determination from a spacecraft. The signal to noise ratio of known tidal variability to altimeter measurement of sea level above the ellipsoid was 0.1. A sample was obtained in a 5 deg x 5 deg area approximately once every four days. The randomly spaced time series was analyzed using two independent least squares techniques.

  11. Mesoscale eddies transport deep-sea sediments.

    PubMed

    Zhang, Yanwei; Liu, Zhifei; Zhao, Yulong; Wang, Wenguang; Li, Jianru; Xu, Jingping

    2014-08-04

    Mesoscale eddies, which contribute to long-distance water mass transport and biogeochemical budget in the upper ocean, have recently been taken into assessment of the deep-sea hydrodynamic variability. However, how such eddies influence sediment movement in the deepwater environment has not been explored. Here for the first time we observed deep-sea sediment transport processes driven by mesoscale eddies in the northern South China Sea via a full-water column mooring system located at 2100 m water depth. Two southwestward propagating, deep-reaching anticyclonic eddies passed by the study site during January to March 2012 and November 2012 to January 2013, respectively. Our multiple moored instruments recorded simultaneous or lagging enhancement of suspended sediment concentration with full-water column velocity and temperature anomalies. We interpret these suspended sediments to have been trapped and transported from the southwest of Taiwan by the mesoscale eddies. The net near-bottom southwestward sediment transport by the two events is estimated up to one million tons. Our study highlights the significance of surface-generated mesoscale eddies on the deepwater sedimentary dynamic process.

  12. Extreme Longevity in Proteinaceous Deep-Sea Corals

    SciTech Connect

    Roark, E B; Guilderson, T P; Dunbar, R B; Fallon, S J; Mucciarone, D A

    2009-02-09

    Deep-sea corals are found on hard substrates on seamounts and continental margins world-wide at depths of 300 to {approx}3000 meters. Deep-sea coral communities are hotspots of deep ocean biomass and biodiversity, providing critical habitat for fish and invertebrates. Newly applied radiocarbon age date from the deep water proteinaceous corals Gerardia sp. and Leiopathes glaberrima show that radial growth rates are as low as 4 to 35 {micro}m yr{sup -1} and that individual colony longevities are on the order of thousands of years. The management and conservation of deep sea coral communities is challenged by their commercial harvest for the jewelry trade and damage caused by deep water fishing practices. In light of their unusual longevity, a better understanding of deep sea coral ecology and their interrelationships with associated benthic communities is needed to inform coherent international conservation strategies for these important deep-sea ecosystems.

  13. Total nitrogen content of deep sea basalts

    NASA Technical Reports Server (NTRS)

    Norris, T. L.; Schaeffer, O. A.

    1982-01-01

    An estimate of the total nitrogen content of the earth's mantle, aimed at furnishing a further constraint for earth atmosphere origin and evolution models, was attempted through thermal neutron activation analysis via N-14(n,p)C-14 for the case of deep sea basalt glasses from the East Pacific Rise, the Mid-Atlantic Rift, and the Juan de Fuca Ridge. The increased nitrogen abundance of matrix material from the same samples as the glasses may be due to the incorporation of chemically-bound nitrogen from sea water, rather than dissolved molecular nitrogen. A discussion is presented of factors affecting observed basalt nitrogen content and its interpretation in terms of mantle nitrogen abundance. A 2 ppm N lower limit is estimated for the mantle.

  14. Oxygen isotopes in deep-sea spherules

    NASA Technical Reports Server (NTRS)

    Clayton, Robert N.; Mayeda, Toshiko K.; Brownlee, Donald E.

    1986-01-01

    Oxygen isotopic compositions have been measured on several size fractions of deep-sea spherules of extraterrestrial origin. The silicate spherules have an isotopic composition unlike that of any known macrometeorite. Their pre-terrestrial compositions may have been similar to those of C3 chondrites or the anhydrous component of C2 chondrites, the latter being preferred on chemical grounds. Metallic particles oxidize in the upper atmosphere, and sample a region for which no previous oxygen isotope data exist. This part of the atmosphere, above about 100 km, is apparently strongly enriched in the heavy isotopes of oxygen.

  15. Modeling deep convection in the Greenland Sea

    NASA Technical Reports Server (NTRS)

    Hakkinen, S.; Mellor, G. L.; Kantha, L. H.

    1992-01-01

    The development of deep convective events in the high-latitude ocean is studied using a three-dimensional, coupled ice-ocean model. Oceanic mixing is described according to the level 2.5 turbulence closure scheme in which convection occurs in a continuous way, i.e., convective adjustment is not invoked. The model is forced by strong winds and surface cooling. Strong upwelling at the multilyear ice edge and consequent entrainment of warm Atlantic waters into the mixed layer is produced by winds parallel to the ice edge. Concomitant cooling drives deep convection and produces chimneylike structures. Inclusion of a barotropic mean flow over topography to the model provides important preconditioning and selects the location of deep convection. The most efficient preconditioning occurs at locations where the flow ascends a slope. In a stratified environment similar to the Greenland Sea with a 12 m/s wind the model simulations show that localized deep convection takes place after about 10 days to depths of 1000 m.

  16. A Deep Hydrographic Section Across the Tasman Sea.

    DTIC Science & Technology

    1985-09-01

    RESEARCH LABORATORY RANRL TECHNICAL MEMORANDUM (EXTERNAL) 18/85 A DEEP HYDROGRAPHIC SECTION ACROSS THE TASMAN SEA P.J. Mulhearn -’I ’ THE UNITED STATES...NTIS GRA&IDTIC TAB Unannouncei El JUstif icatio A DEEP HYDROGRAPHIC SECTIONACROSS THE TASMAN SEA By Distribution/ P.J. MULHEARN Availability Codes...Avail andor Dit Special ABSTRACT D *,n [ins memorandum reports on the results obtained from a deep hydrographic section across the Tasman Sea in December

  17. Factors controlling ebro deep-sea fan growth, Mediterranean Sea

    SciTech Connect

    Nelson, C.H.; Maldonado, A.; Alonso, B.; Palanques, A.; Ryan, W.B.F.; Kastens, K.; O'Connel, S.

    1985-01-01

    Tectonic, sediment-source and sea-level factors control depositional patterns of the Ebro deep-sea fan system. In unstable, steep continental slope terrain, mass movement of material results in wide gullied canyons and formation of non-channelized debris aprons. These fan channels develop low sinuosity and generally traverse the continental rise without feeding into depositional lobes because of steep gradients (1:50 to 1:100) and sediment draining into the subsiding Valencia Valley graben. An abundance of sediment input points from mass failure and many river-fed canyons contributes to a depositional pattern of side-by-side debris aprons and separate channel-levee complexes. When a large sediment supply feeds a channel for a relatively long period 1) fan valley sinuosity increases: 2) channel walls are modified through undercutting, slumping, and crevasse splays: 3) channel bifurcation occurs: 4) incipient depositional lobe formation begins. Lowering of sea levels in Late Pleistocene time permitted the access of coarse river sediment to slope valleys and promoted deposition of numerous turbidites and active growth of the fan. During the Holocene, when sea levels have been high, a regime of hemipelagic sedimentation, mass movement, and debris apron sedimentation has dominated.

  18. Archaeal Diversity Associated with Deep Sea Whalefalls

    NASA Astrophysics Data System (ADS)

    Wilpiszeski, R.; Goffredi, S.; Turk, K.; Vrijenhoek, R.; House, C. H.; Orphan, V.

    2005-12-01

    Deep sea whale fall sites support a diverse population of organisms in an otherwise sparsely populated environment. While the macro- and megafauna of these ecosystems have been investigated in some detail, less is known about the nature of associated microbial populations. 16S rRNA gene surveys were used to evaluate the diversity of Archaea in the sediment below one such whale fall at 2800 m water depth and at a nearby control site. A variety of Archaea were identified, including diverse uncultured marine crenarchaeota, phylotypes related to hydrogenotrophic methanogens (Methanogenium spp.), and methylotrophic methanogens associated with the Methanococcoides. No methanogens were discovered at the control site, while hydrogenotrophic methanogens accounted for approximately 20% of the samples from surface sediments below the whale and 35% of the Archaea identified from 12.5 to 15 cm below the whale; the single methylotrophic methanogen was identified within the 12.5 to 15 cm depth sample. The presence of methanogenic phylotypes associated with the whale fall corroborates geochemical observations of elevated methane concentrations observed in the shallow sediments directly beneath the whale fall. This combined geochemical and microbiological evidence suggests that near surface organic matter remineralization is occurring via a methanogenic pathway within this deep sea whale fall habitat rather than the typical sulfidogenic dominated diagenesis commonly observed at other whale fall locations and within shallow marine sediments worldwide.

  19. Deep-Sea Submarine 'Ben Franklin'

    NASA Technical Reports Server (NTRS)

    1969-01-01

    The deep-sea submarine 'Ben Franklin' is being docked in the harbor. Named for American patriot and inventor Ben Franklin, who discovered the Gulf Steam, the 50-foot Ben Franklin was built between 1966 and 1968 in Switzerland for deep-ocean explorer Jacques Piccard and the Grumman Aircraft Engineering Corporation. The submersible made a famous 30-day drift dive off the East Coast of the United States and Canada in 1969 mapping the Gulf Stream's currents and sea life. It also made space exploration history by studying the behavior of aquanauts in a sealed, self-contained, self-sufficient capsule for NASA. On July 14, 1969, the Ben Franklin was towed to the high-velocity center of the Stream off the coast of Palm Beach, Florida. With a NASA observer on board, the sub descended to 1,000 feet off of Riviera Beach, Florida and drifted 1,400 miles north with the current for more than four weeks, reemerging near Maine. During the course of the dive, NASA conducted exhaustive analyses of virtually every aspect of onboard life. They measured sleep quality and patterns, sense of humor and behavioral shifts, physical reflexes, and the effect of a long-term routine on the crew. The submarine's record-shattering dive influenced the design of Apollo and Skylab missions and continued to guide NASA scientists as they devised future marned space-flight missions.

  20. Deep-Sea Research Submarine 'Ben Franklin'

    NASA Technical Reports Server (NTRS)

    1969-01-01

    This is an aerial view of the deep-sea research submarine 'Ben Franklin' at dock. Named for American patriot and inventor Ben Franklin, who discovered the Gulf Steam, the 50-foot Ben Franklin was built between 1966 and 1968 in Switzerland for deep-ocean explorer Jacques Piccard and the Grumman Aircraft Engineering Corporation. The submersible made a famous 30-day drift dive off the East Coast of the United States and Canada in 1969 mapping the Gulf Stream's currents and sea life, and also made space exploration history by studying the behavior of aquanauts in a sealed, self-contained, self-sufficient capsule for NASA. On July 14, 1969, the Ben Franklin was towed to the high-velocity center of the Stream off the coast of Palm Beach, Florida. With a NASA observer on board, the sub descended to 1,000 feet off of Riviera Beach, Florida and drifted 1,400 miles north with the current for more than four weeks, reemerging near Maine. During the course of the dive, NASA conducted exhaustive analyses of virtually every aspect of onboard life. They measured sleep quality and patterns, sense of humor and behavioral shifts, physical reflexes, and the effects of a long-term routine on the crew. The submarine's record-shattering dive influenced the design of Apollo and Skylab missions and continued to guide NASA scientists as they devised future marned space-flight missions.

  1. First biological measurements of deep-sea corals from the Red Sea.

    PubMed

    Roder, C; Berumen, M L; Bouwmeester, J; Papathanassiou, E; Al-Suwailem, A; Voolstra, C R

    2013-10-03

    It is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with 'deep-sea' and 'cold-water' corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red Sea but occurs in deep cold waters outside the Red Sea raising interesting questions about presumed environmental constraints for other deep-sea corals. Our findings suggest that the present understanding of deep-sea coral persistence and resilience needs to be revisited.

  2. Ancient origin of the modern deep-sea fauna.

    PubMed

    Thuy, Ben; Gale, Andy S; Kroh, Andreas; Kucera, Michal; Numberger-Thuy, Lea D; Reich, Mike; Stöhr, Sabine

    2012-01-01

    The origin and possible antiquity of the spectacularly diverse modern deep-sea fauna has been debated since the beginning of deep-sea research in the mid-nineteenth century. Recent hypotheses, based on biogeographic patterns and molecular clock estimates, support a latest Mesozoic or early Cenozoic date for the origin of key groups of the present deep-sea fauna (echinoids, octopods). This relatively young age is consistent with hypotheses that argue for extensive extinction during Jurassic and Cretaceous Oceanic Anoxic Events (OAEs) and the mid-Cenozoic cooling of deep-water masses, implying repeated re-colonization by immigration of taxa from shallow-water habitats. Here we report on a well-preserved echinoderm assemblage from deep-sea (1000-1500 m paleodepth) sediments of the NE-Atlantic of Early Cretaceous age (114 Ma). The assemblage is strikingly similar to that of extant bathyal echinoderm communities in composition, including families and genera found exclusively in modern deep-sea habitats. A number of taxa found in the assemblage have no fossil record at shelf depths postdating the assemblage, which precludes the possibility of deep-sea recolonization from shallow habitats following episodic extinction at least for those groups. Our discovery provides the first key fossil evidence that a significant part of the modern deep-sea fauna is considerably older than previously assumed. As a consequence, most major paleoceanographic events had far less impact on the diversity of deep-sea faunas than has been implied. It also suggests that deep-sea biota are more resilient to extinction events than shallow-water forms, and that the unusual deep-sea environment, indeed, provides evolutionary stability which is very rarely punctuated on macroevolutionary time scales.

  3. Ancient Origin of the Modern Deep-Sea Fauna

    PubMed Central

    Thuy, Ben; Gale, Andy S.; Kroh, Andreas; Kucera, Michal; Numberger-Thuy, Lea D.; Reich, Mike; Stöhr, Sabine

    2012-01-01

    The origin and possible antiquity of the spectacularly diverse modern deep-sea fauna has been debated since the beginning of deep-sea research in the mid-nineteenth century. Recent hypotheses, based on biogeographic patterns and molecular clock estimates, support a latest Mesozoic or early Cenozoic date for the origin of key groups of the present deep-sea fauna (echinoids, octopods). This relatively young age is consistent with hypotheses that argue for extensive extinction during Jurassic and Cretaceous Oceanic Anoxic Events (OAEs) and the mid-Cenozoic cooling of deep-water masses, implying repeated re-colonization by immigration of taxa from shallow-water habitats. Here we report on a well-preserved echinoderm assemblage from deep-sea (1000–1500 m paleodepth) sediments of the NE-Atlantic of Early Cretaceous age (114 Ma). The assemblage is strikingly similar to that of extant bathyal echinoderm communities in composition, including families and genera found exclusively in modern deep-sea habitats. A number of taxa found in the assemblage have no fossil record at shelf depths postdating the assemblage, which precludes the possibility of deep-sea recolonization from shallow habitats following episodic extinction at least for those groups. Our discovery provides the first key fossil evidence that a significant part of the modern deep-sea fauna is considerably older than previously assumed. As a consequence, most major paleoceanographic events had far less impact on the diversity of deep-sea faunas than has been implied. It also suggests that deep-sea biota are more resilient to extinction events than shallow-water forms, and that the unusual deep-sea environment, indeed, provides evolutionary stability which is very rarely punctuated on macroevolutionary time scales. PMID:23071660

  4. The Deep Seas--Unexpectedly, An Astounding Variety of Life

    ERIC Educational Resources Information Center

    MOSAIC, 1976

    1976-01-01

    As oceanographic technology advances, the study of deep-sea environments is accelerating. Numerous ecological theories concerning deep-sea food relationships, environmental extremes, and life forms are changing as the environments of the deepest ocean trenches are studied. Thousands of new species are being discovered and studied constantly. (MA)

  5. Platinum group nuggets in deep sea sediments

    NASA Technical Reports Server (NTRS)

    Brownlee, D. E.; Bates, B. A.; Wheelock, M. M.

    1984-01-01

    The existence of iron meteor oblation spheres in deep sea sediments was known for over a century. These spheres generally were believed to be composed of either pure magnetite and wustite or an oxide shell surrounding a NiFe metal core. A large number of 300 micron to 600 micron spheres found were pure oxide spheres, usually containing a solitary 10 micron platinum group nugget (pgn) composed almost entirely of group VIII metals. Twelve PGN's were analyzed and most had chondritic abundances with some depletions that correlate with element volatility. PGN formation by oxidation of a molten metal sphere entering the atmosphere cannot occur if the oxygen abundance in the atmosphere is less than half of its present value. The first appearance of PGN's in the geological record should mark when, in the Earth's history, oxygen rose to this level.

  6. New Waves in Marine Science Symposium: Deep Sea !Discoveries!

    ERIC Educational Resources Information Center

    Allen, Betty, Comp.

    1989-01-01

    Presented are the abstracts from three research projects involving deep sea technology which were a part of a marine science symposium. Five sets of activities on deep sea science are included, one each for grades K-2, 3-5, 6-8 and 9-12, and informal education. (CW)

  7. The dynamics of biogeographic ranges in the deep sea.

    PubMed

    McClain, Craig R; Hardy, Sarah Mincks

    2010-12-07

    Anthropogenic disturbances such as fishing, mining, oil drilling, bioprospecting, warming, and acidification in the deep sea are increasing, yet generalities about deep-sea biogeography remain elusive. Owing to the lack of perceived environmental variability and geographical barriers, ranges of deep-sea species were traditionally assumed to be exceedingly large. In contrast, seamount and chemosynthetic habitats with reported high endemicity challenge the broad applicability of a single biogeographic paradigm for the deep sea. New research benefiting from higher resolution sampling, molecular methods and public databases can now more rigorously examine dispersal distances and species ranges on the vast ocean floor. Here, we explore the major outstanding questions in deep-sea biogeography. Based on current evidence, many taxa appear broadly distributed across the deep sea, a pattern replicated in both the abyssal plains and specialized environments such as hydrothermal vents. Cold waters may slow larval metabolism and development augmenting the great intrinsic ability for dispersal among many deep-sea species. Currents, environmental shifts, and topography can prove to be dispersal barriers but are often semipermeable. Evidence of historical events such as points of faunal origin and climatic fluctuations are also evident in contemporary biogeographic ranges. Continued synthetic analysis, database construction, theoretical advancement and field sampling will be required to further refine hypotheses regarding deep-sea biogeography.

  8. Adapting to the Deep Sea: A Fun Activity with Bioluminescence

    ERIC Educational Resources Information Center

    Rife, Gwynne

    2006-01-01

    Over the past decade, much has been learned about the ocean's secrets and especially about the creatures of the deep sea. The deepest parts of the oceans are currently the focus of many new discoveries in both the physical and biological sciences. Middle school students find the deep sea fascinating and especially seem to enjoy its mysterious and…

  9. Taxonomic research on deep-sea macrofauna in the South China Sea using the Chinese deep-sea submersible Jiaolong.

    PubMed

    Li, Xinzheng

    2017-01-05

    This paper reviews the taxonomic and biodiversity studies of the deep-sea invertebrates in the South China Sea based on the samples collected by the Chinese manned deep-sea submersible Jiaolong. To date, six new species were described, including the sponges Lophophysema eversa Gong, Li & Qiu, 2014, Saccocalyx microhexactin Gong, Li & Qiu, 2015, and Semperella jiaolongae Gong, Li & Qiu, 2015 as well as the crustaceans Uroptychus jiaolongae Dong & Li, 2015, Uroptychus spinulosus Dong & Li, 2015 and Globospongicola jiaolongi Jiang, Kou & Li, 2015, and some newly recorded species from the South China Sea were reported. The Bathymodiolus platifrons-Shinkaia crosnieri deep-sea cold seep community was reported (Li, 2015), as was the mitochondrial genome of the glass sponge Lophophysema eversa Gong, Li & Qiu, 2014 (Zhang et al., 2015). The population structures of two dominant species, the shrimp Shinkaia crosnieri and the mussel Bathymodiolus platifrons, from the cold seep Bathymodiolus platifrons-Shinkaia crosnieri community in the South China Sea and the hydrothermal vents in the Okinawa Trough, were compared using molecular analysis. The systematic position of the shrimp genus Globospongicola was discussed based on 16S rRNA gene sequences. This article is protected by copyright. All rights reserved.

  10. U.S. Deep-Sea Tsunameter Network Fully Operational

    DTIC Science & Technology

    2008-09-01

    southeast. On April 16, 2007, DART II station 55401 was established in the Tasman Sea . In March 2008, the DART team assisted in the second Australian...U.S. Deep- Sea Tsunameter Network Fully Operational Douglas Maxwell, Shannon McArthur, William Hansen, Richard Bouchard, Ian Sears, Jack Higgs and...of deep- sea tsunameters. This effort was an integral part of the National Tsunami Hazard Mitigation Program. The Tsunami Program is part of a

  11. A checklist of the deep sea fishes of the Levant Sea, Mediterranean Sea.

    PubMed

    Goren, Menachem; Galil, Bella S

    2015-08-04

    We list sixty five fish species collected at depths greater than 500 m in the Levant Basin, including 10 depth records. The Levantine bathyal ichthyofauna is characterized by its eurybathy, with an upper bathymetric boundary that permitted penetration of the shallow Gibraltar and Siculo-Tunisian sills, and a much lower bathymetric boundary than recorded for conspecifics elsewhere. The opportunistic and resilient ichthyofauna re-colonized recently the deep-sea following the last anoxic event (~ 6 kyr), forming assemblages notably distinct from those in the western Mediterranean. The exploration and production of deep seabed hydrocarbons have raised the specter of severe direct impacts to the deep habitats. There is an urgent need for documenting the full extent of deep-sea biodiversity, and for providing information for the development of competent and pragmatic management plans and effective conservation policies.

  12. Fisheries: deep-sea fishes qualify as endangered.

    PubMed

    Devine, Jennifer A; Baker, Krista D; Haedrich, Richard L

    2006-01-05

    Criteria from the World Conservation Union (IUCN) have been used to classify marine fish species as endangered since 1996, but deep-sea fish have not so far been evaluated--despite their vulnerability to aggressive deepwater fishing as a result of certain life-history traits. Here we use research-survey data to show that five species of deep-sea fish have declined over a 17-year period in the Canadian waters of the northwest Atlantic to such an extent that they meet the IUCN criteria for being critically endangered. Our results indicate that urgent action is needed for the sustainable management of deep-sea fisheries.

  13. Oxygen isotopes in deep sea spherules

    NASA Technical Reports Server (NTRS)

    Mayeda, T. K.; Clayton, R. N.; Brownlee, D. E.

    1984-01-01

    The determination of the genetic relationships between the dust and small particles in the solar system, and the meteorites and larger bodies are examined. Oxygen isotopes proved useful in the identification of such relationships between one meteorite group and another. Of the various samples of submillimeter extraterrestrial particles available for laboratory study, only the deep sea spherules are abundant enough for precise oxygen isotope analysis using existing techniques. Complications arise in interpretation of the isotopic data, since these particles were melted during passage through the Earth's atmosphere, and have been in contact with seawater for prolonged periods. Spherules that were originally silicates are considered with the originally metallic ones to deduce their preterrestrial isotopic compositions. The type 1 spherules which enter the atmosphere as metallic particles, contain only atmospheric oxygen. The type S spherules contain a mixture of atmospheric oxygen and their original extraterrestrial oxygen. It is suggested that the Earth's mesosphere is strongly enriched in heavy isotopes of oxygen at altitudes near 90 km at which the iron particles are oxidized. Fractionation due to the combined diffusion of O atoms and O2 molecules may be responsible.

  14. Low incidence of clonality in cold water corals revealed through the novel use of standardized protocol adapted to deep sea sampling

    USGS Publications Warehouse

    Becheler, Ronan; Cassone, Anne-Laure; Noel, Philippe; Mouchel, Olivier; Morrison, Cheryl; Arnaud-Haond, Sophie

    2016-01-01

    Sampling in the deep sea is a technical challenge, which has hindered the acquisition of robust datasets that are necessary to determine the fine-grained biological patterns and processes that may shape genetic diversity. Estimates of the extent of clonality in deep-sea species, despite the importance of clonality in shaping the local dynamics and evolutionary trajectories, have been largely obscured by such limitations. Cold-water coral reefs along European margins are formed mainly by two reef-building species, Lophelia pertusa and Madrepora oculata. Here we present a fine-grained analysis of the genotypic and genetic composition of reefs occurring in the Bay of Biscay, based on an innovative deep-sea sampling protocol. This strategy was designed to be standardized, random, and allowed the georeferencing of all sampled colonies. Clonal lineages discriminated through their Multi-Locus Genotypes (MLG) at 6–7 microsatellite markers could thus be mapped to assess the level of clonality and the spatial spread of clonal lineages. High values of clonal richness were observed for both species across all sites suggesting a limited occurrence of clonality, which likely originated through fragmentation. Additionally, spatial autocorrelation analysis underlined the possible occurrence of fine-grained genetic structure in several populations of both L. pertusa and M. oculata. The two cold-water coral species examined had contrasting patterns of connectivity among canyons, with among-canyon genetic structuring detected in M. oculata, whereas L. pertusa was panmictic at the canyon scale. This study exemplifies that a standardized, random and georeferenced sampling strategy, while challenging, can be applied in the deep sea, and associated benefits outlined here include improved estimates of fine grained patterns of clonality and dispersal that are comparable across sites and among species.

  15. Challenging Oil Bioremediation at Deep-Sea Hydrostatic Pressure.

    PubMed

    Scoma, Alberto; Yakimov, Michail M; Boon, Nico

    2016-01-01

    The Deepwater Horizon accident has brought oil contamination of deep-sea environments to worldwide attention. The risk for new deep-sea spills is not expected to decrease in the future, as political pressure mounts to access deep-water fossil reserves, and poorly tested technologies are used to access oil. This also applies to the response to oil-contamination events, with bioremediation the only (bio)technology presently available to combat deep-sea spills. Many questions about the fate of petroleum-hydrocarbons within deep-sea environments remain unanswered, as well as the main constraints limiting bioremediation under increased hydrostatic pressures and low temperatures. The microbial pathways fueling oil bioassimilation are unclear, and the mild upregulation observed for beta-oxidation-related genes in both water and sediments contrasts with the high amount of alkanes present in the spilled oil. The fate of solid alkanes (tar), hydrocarbon degradation rates and the reason why the most predominant hydrocarbonoclastic genera were not enriched at deep-sea despite being present at hydrocarbon seeps at the Gulf of Mexico have been largely overlooked. This mini-review aims at highlighting the missing information in the field, proposing a holistic approach where in situ and ex situ studies are integrated to reveal the principal mechanisms accounting for deep-sea oil bioremediation.

  16. Challenging Oil Bioremediation at Deep-Sea Hydrostatic Pressure

    PubMed Central

    Scoma, Alberto; Yakimov, Michail M.; Boon, Nico

    2016-01-01

    The Deepwater Horizon accident has brought oil contamination of deep-sea environments to worldwide attention. The risk for new deep-sea spills is not expected to decrease in the future, as political pressure mounts to access deep-water fossil reserves, and poorly tested technologies are used to access oil. This also applies to the response to oil-contamination events, with bioremediation the only (bio)technology presently available to combat deep-sea spills. Many questions about the fate of petroleum-hydrocarbons within deep-sea environments remain unanswered, as well as the main constraints limiting bioremediation under increased hydrostatic pressures and low temperatures. The microbial pathways fueling oil bioassimilation are unclear, and the mild upregulation observed for beta-oxidation-related genes in both water and sediments contrasts with the high amount of alkanes present in the spilled oil. The fate of solid alkanes (tar), hydrocarbon degradation rates and the reason why the most predominant hydrocarbonoclastic genera were not enriched at deep-sea despite being present at hydrocarbon seeps at the Gulf of Mexico have been largely overlooked. This mini-review aims at highlighting the missing information in the field, proposing a holistic approach where in situ and ex situ studies are integrated to reveal the principal mechanisms accounting for deep-sea oil bioremediation. PMID:27536290

  17. Nuclear astrophysics: Deep-sea diving for stellar debris

    NASA Astrophysics Data System (ADS)

    Thielemann, Friedrich-Karl

    2015-12-01

    Deep-sea sediments reveal the production sites of the heaviest chemical elements in the Universe to be neutron star mergers -- rare events that eject large amounts of mass -- and not core-collapse supernovae.

  18. Challenging the paradigms of deep-sea ecology.

    PubMed

    Danovaro, Roberto; Snelgrove, Paul V R; Tyler, Paul

    2014-08-01

    Deep-sea ecosystems represent Earth's major ecological research frontier. Focusing on seafloor ecosystems, we demonstrate how new technologies underpin discoveries that challenge major ecological hypotheses and paradigms, illuminating new deep-sea geosphere-biosphere interactions. We now recognize greater habitat complexity, new ecological interactions and the importance of 'dark energy', and chemosynthetic production in fuelling biodiversity. We also acknowledge functional hotspots that contradict a food-poor, metabolically inactive, and minor component of global carbon cycles. Symbioses appear widespread, revealing novel adaptations. Populations show complex spatial structure and evolutionary histories. These new findings redefine deep-sea ecology and the role of Earth's largest biome in global biosphere functioning. Indeed, deep-sea exploration can open new perspectives in ecological research to help mitigate exploitation impacts.

  19. Engineering for Deep Sea Drilling for Scientific Purposes

    DTIC Science & Technology

    1980-01-01

    Atmospheric Leonard C. Heoer Administration Center for Law and Social Policy National Fisheries Service Washington, D.C. Seattle, Washington J. Robert...the Gulf of Mexico appears to have released some 3 million barrels of crude oil. 394 Site selection for scientific deep sea drilling should be...the horizon that can meet the demands of the deep sea drilling programas described by NSF to the committee in September 1979. Thus, sucha vessel would

  20. Deep-Sea Hydrothermal-Vent Sampler

    NASA Technical Reports Server (NTRS)

    Behar, Alberto E.; Venkateswaran, Kasthur; Matthews, Jaret B.

    2008-01-01

    An apparatus is being developed for sampling water for signs of microbial life in an ocean hydrothermal vent at a depth of as much as 6.5 km. Heretofore, evidence of microbial life in deep-sea hydrothermal vents 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 hydrothermal- vent 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 hydrothermal 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 vent 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

  1. A ubiquitous thermoacidophilic archaeon from deep-sea hydrothermal vents

    USGS Publications Warehouse

    Reysenbach, A.-L.; Liu, Yajing; Banta, A.B.; Beveridge, T.J.; Kirshtein, J.D.; Schouten, S.; Tivey, M.K.; Von Damm, Karen L.; Voytek, M.A.

    2006-01-01

    Deep-sea hydrothermal vents are important in global biogeochemical cycles, providing biological oases at the sea floor that are supported by the thermal and chemical flux from the Earth's interior. As hot, acidic and reduced hydrothermal fluids mix with cold, alkaline and oxygenated sea water, minerals precipitate to form porous sulphide-sulphate deposits. These structures provide microhabitats for a diversity of prokaryotes that exploit the geochemical and physical gradients in this dynamic ecosystem. It has been proposed that fluid pH in the actively venting sulphide structures is generally low (pH < 4.5), yet no extreme thermoacidophile has been isolated from vent deposits. Culture-independent surveys based on ribosomal RNA genes from deep-sea hydrothermal deposits have identified a widespread euryarchaeotal lineage, DHVE2 (deep-sea hydrothermal vent euryarchaeotic 2). Despite the ubiquity and apparent deep-sea endemism of DHVE2, cultivation of this group has been unsuccessful and thus its metabolism remains a mystery. Here we report the isolation and cultivation of a member of the DHVE2 group, which is an obligate thermoacidophilic sulphur- or iron-reducing heterotroph capable of growing from pH 3.3 to 5.8 and between 55 and 75??C. In addition, we demonstrate that this isolate constitutes up to 15% of the archaeal population, providing evidence that thermoacidophiles may be key players in the sulphur and iron cycling at deep-sea vents. ?? 2006 Nature Publishing Group.

  2. 46 CFR 167.40-20 - Deep-sea sounding apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SHIPS Certain Equipment Requirements § 167.40-20 Deep-sea sounding apparatus. Nautical school ships shall be equipped with an efficient or electronic deep-sea sounding apparatus. The electronic deep-sea... 46 Shipping 7 2011-10-01 2011-10-01 false Deep-sea sounding apparatus. 167.40-20 Section...

  3. 46 CFR 167.40-20 - Deep-sea sounding apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SHIPS Certain Equipment Requirements § 167.40-20 Deep-sea sounding apparatus. Nautical school ships shall be equipped with an efficient or electronic deep-sea sounding apparatus. The electronic deep-sea... 46 Shipping 7 2010-10-01 2010-10-01 false Deep-sea sounding apparatus. 167.40-20 Section...

  4. Deep-sea channel/submarine-yazoo system of the Labrador Sea: A new deep-water facies model

    SciTech Connect

    Hesse, R.; Rakofsky, A. )

    1992-05-01

    The deep-sea channel/submarine-yazoo system is a newly recognized deep-water depositional environment that is significantly different from previously documented turbidite environments. The new system is in many ways the antithesis of classical deep-sea fans. The purpose of this paper is to present the characteristics and elements of the system, develop a facies model for it, establish the system variables, and discuss its possible significance in the geologic record and in subsurface exploration. Previous investigators of deepwater turbidite sediments often faced difficulties in trying to fit their sequences into traditional single-source, deep-sea fan models. The present model fills part of an obvious gap in interpretation schemes for deep-water clastic sediments.

  5. [Four cases of pulmonary tuberculosis among deep-sea fishermen].

    PubMed

    Ono, Hidemaro; Murakami, Reiko; Tsuruwaka, Mia; Suzuki, Yoshihiko

    2003-06-01

    Pulmonary tuberculosis among deep-sea fishermen was reported. Four pulmonary tuberculosis cases among fishing boat members engaged in deep-sea fishing were registered at the Kesennuma Health Center during three years period from 2000 to 2002. Crew engaging in deep-sea fishing live together in a narrow cabin with inadequate airconditioning for a long period of time, about 1 year. It is difficult to consult with a medical institution in an open sea. If a tuberculosis patient breaks out in a boat, the risk of transmission of tuberculosis to other members is high. In boats of all four cases in this report, about 30 to 70 percent of crew were Indonesian. Indonesia is one of the high burden countries of tuberculosis in the world. The Japanese fishing boat members have received the medical checkup every year. Indonesians have also received the pre-employment medical checkup, however, the improvement in the quality of this medical checkup is required.

  6. Dining in the Deep: The Feeding Ecology of Deep-Sea Fishes.

    PubMed

    Drazen, Jeffrey C; Sutton, Tracey T

    2017-01-03

    Deep-sea fishes inhabit ∼75% of the biosphere and are a critical part of deep-sea food webs. Diet analysis and more recent trophic biomarker approaches, such as stable isotopes and fatty-acid profiles, have enabled the description of feeding guilds and an increased recognition of the vertical connectivity in food webs in a whole-water-column sense, including benthic-pelagic coupling. Ecosystem modeling requires data on feeding rates; the available estimates indicate that deep-sea fishes have lower per-individual feeding rates than coastal and epipelagic fishes, but the overall predation impact may be high. A limited number of studies have measured the vertical flux of carbon by mesopelagic fishes, which appears to be substantial. Anthropogenic activities are altering deep-sea ecosystems and their services, which are mediated by trophic interactions. We also summarize outstanding data gaps.

  7. Dining in the Deep: The Feeding Ecology of Deep-Sea Fishes

    NASA Astrophysics Data System (ADS)

    Drazen, Jeffrey C.; Sutton, Tracey T.

    2017-01-01

    Deep-sea fishes inhabit ˜75% of the biosphere and are a critical part of deep-sea food webs. Diet analysis and more recent trophic biomarker approaches, such as stable isotopes and fatty-acid profiles, have enabled the description of feeding guilds and an increased recognition of the vertical connectivity in food webs in a whole-water-column sense, including benthic-pelagic coupling. Ecosystem modeling requires data on feeding rates; the available estimates indicate that deep-sea fishes have lower per-individual feeding rates than coastal and epipelagic fishes, but the overall predation impact may be high. A limited number of studies have measured the vertical flux of carbon by mesopelagic fishes, which appears to be substantial. Anthropogenic activities are altering deep-sea ecosystems and their services, which are mediated by trophic interactions. We also summarize outstanding data gaps.

  8. Environmental Adaptation of Dihydrofolate Reductase from Deep-Sea Bacteria.

    PubMed

    Ohmae, Eiji; Gekko, Kunihiko; Kato, Chiaki

    2015-01-01

    In order to elucidate the molecular adaptation mechanisms of enzymes to the high hydrostatic pressure of the deep sea, we cloned, purified, and characterized more than ten dihydrofolate reductases (DHFRs) from bacteria living in deep-sea and ambient atmospheric pressure environments. The nucleotide and amino acid sequences of these DHFRs indicate the deep-sea bacteria are adapted to their environments after the differentiation of their genus from ancestors inhabiting atmospheric pressure environments. In particular, the backbone structure of the deep-sea DHFR from Moritella profunda (mpDHFR) almost overlapped with the normal homolog from Escherichia coli (ecDHFR). Thus, those of other DHFRs would also overlap on the basis of their sequence similarities. However, the structural stability of both DHFRs was quite different: compared to ecDHFR, mpDHFR was more thermally stable but less stable against urea and pressure unfolding. The smaller volume changes due to unfolding suggest that the native structure of mpDHFR has a smaller cavity and/or enhanced hydration compared to ecDHFR. High hydrostatic pressure reduced the enzymatic activity of many DHFRs, but three deep-sea DHFRs and the D27E mutant of ecDHFR exhibited pressure-dependent activation. The inverted activation volumes from positive to negative values indicate the modification of their structural dynamics, conversion of the rate-determining step of the enzymatic reaction, and different contributions of the cavity and hydration to the transition-state structure. Since the cavity and hydration depend on amino acid side chains, DHFRs would adapt to the deep-sea environment by regulating the cavity and hydration by substituting their amino acid side chains without altering their backbone structure. The results of this study clearly indicate that the cavity and hydration play important roles in the adaptation of enzymes to the deep-sea environment.

  9. Fungi and macroaggregation in deep-sea sediments.

    PubMed

    Damare, Samir; Raghukumar, Chandralata

    2008-07-01

    Whereas fungi in terrestrial soils have been well studied, little is known of them in deep-sea sediments. Recent studies have demonstrated the presence of fungal hyphae in such sediments but in low abundance. We present evidence in this study that one of the apparent reasons for the poor detection of fungi in deep-sea sediments is their cryptic presence in macroaggregates. Fungal biomass carbon from different core sections of deep-sea sediments from approximately 5000 m depth in the Central Indian Ocean was estimated based on direct microscopic detection of fungal mycelia. Treatment of sediment samples with ethylenediamine tetra-acetic acid (EDTA) enabled more frequent detection and significantly higher biomass than in samples without such treatment. Treatment with EDTA resulted in detecting various stages of breakdown of aggregates in the sediments, gradually revealing the presence of fungal hyphae within them. Experimental studies of a deep-sea, as well as three terrestrial isolates of fungi, showed that all could grow at 200 bar and 5 degrees C in a nutrient medium and in deep-sea sediment extract. Hyphae of fungi grown in sediment extract under the above conditions showed various stages of accretion of particles around them, leading to the formation of aggregates. Such aggregates showed the presence of humic material, carbohydrate, and proteins. We suggest that fungi in deep-sea sediments may be involved in humic aggregate formation by processes very similar to those in terrestrial sediments. The importance of such a process in carbon sequestration and food web in the deep sea needs to be examined.

  10. Review of Deep-Sea Ecology and Monitoring as They Relate to Deep-Sea Oil and Gas Operations

    SciTech Connect

    Kropp, Roy K.

    2004-01-30

    This review summarizes available information concerning deep-sea benthic ecology and how that information might be used to monitor and eventually reduce the potential impacts resulting from oil and gas production activities. The paper provides a brief overview of deep-sea ecology and benthic faunal groups and summarizes some of the physical and biological features that may be important in evaluating potential impacts. In addition, presented is a synopsis of issues related to the design of a sampling program and a discussion of analytical considerations related to the uncertain knowledge of deep faunas. Also included is an overview of some of the variety of sampling techniques and equipment available to study the deep sea. The review concludes with management considerations and recommendations.

  11. Light and vision in the deep-sea benthos: II. Vision in deep-sea crustaceans.

    PubMed

    Frank, Tamara M; Johnsen, Sönke; Cronin, Thomas W

    2012-10-01

    Using new collecting techniques with the Johnson-Sea-Link submersible, eight species of deep-sea benthic crustaceans were collected with intact visual systems. Their spectral sensitivities and temporal resolutions were determined shipboard using electroretinography. Useable spectral sensitivity data were obtained from seven species, and in the dark-adapted eyes, the spectral sensitivity peaks were in the blue region of the visible spectrum, ranging from 470 to 497 nm. Under blue chromatic adaptation, a secondary sensitivity peak in the UV portion of the spectrum appeared for two species of anomuran crabs: Eumunida picta (λ(max)363 nm) and Gastroptychus spinifer (λ(max)383 nm). Wavelength-specific differences in response waveforms under blue chromatic adaptation in these two species suggest that two populations of photoreceptor cells are present. Temporal resolution was determined in all eight species using the maximum critical flicker frequency (CFF(max)). The CFF(max) for the isopod Booralana tricarinata of 4 Hz proved to be the lowest ever measured using this technique, and suggests that this species is not able to track even slow-moving prey. Both the putative dual visual pigment system in the crabs and the extremely slow eye of the isopod may be adaptations for seeing bioluminescence in the benthic environment.

  12. Drivers of foraminiferal evolution and extinction in the deep sea

    NASA Astrophysics Data System (ADS)

    van Kerckhoven, L.; Hayward, B. W.

    2009-04-01

    This PhD research aims to increase understanding of the causes of global evolution and extinction in the deep sea. This is addressed by focusing on the enigmatic extinction of a distinctive group of cosmopolitan deep-sea benthic foraminifera during the late Pliocene-Middle Pleistocene "Last Global Extinction" (LGE) (3 - 0.12 Ma). This so-called "Extinction Group", comprising nearly 100 species (c. 25% of deep-sea foraminiferal diversity at that time), all shared a similar morphology of elongate, cylindrical and uniserial tests with small, specialised apertures. To find out what type of change could have been so all-encompassing to decimate and wipe out this abundant and cosmopolitan group of foraminifera, even precluding them to re-immigrate from refugia, we extend the studies back in time. The LGE was coeval with the pulsed expansion of the northern hemisphere ice cap, rendering deep-sea conditions colder and more oxygenated during increasingly severe glacials. The dominant hypothesis states that the extinct taxa and/or their food supply, both adapted to a Greenhouse World (65 - 33.5 Ma), were unable to cope with these large and rapid changes in the deep-sea environment. To test this proposition, we obtained a record of the occurrence and abundance of the "Extinction Group" species in ODP Sites 689 (Southern Ocean) and 1211 (North Pacific Ocean) throughout the Cenozoic, allowing the investigation of palaeoenvironmental drivers of abundance, extinctions and originations of species.

  13. Deep-sea diversity patterns are shaped by energy availability.

    PubMed

    Woolley, Skipton N C; Tittensor, Derek P; Dunstan, Piers K; Guillera-Arroita, Gurutzeta; Lahoz-Monfort, José J; Wintle, Brendan A; Worm, Boris; O'Hara, Timothy D

    2016-05-19

    The deep ocean is the largest and least-explored ecosystem on Earth, and a uniquely energy-poor environment. The distribution, drivers and origins of deep-sea biodiversity remain unknown at global scales. Here we analyse a database of more than 165,000 distribution records of Ophiuroidea (brittle stars), a dominant component of sea-floor fauna, and find patterns of biodiversity unlike known terrestrial or coastal marine realms. Both patterns and environmental predictors of deep-sea (2,000-6,500 m) species richness fundamentally differ from those found in coastal (0-20 m), continental shelf (20-200 m), and upper-slope (200-2,000 m) waters. Continental shelf to upper-slope richness consistently peaks in tropical Indo-west Pacific and Caribbean (0-30°) latitudes, and is well explained by variations in water temperature. In contrast, deep-sea species show maximum richness at higher latitudes (30-50°), concentrated in areas of high carbon export flux and regions close to continental margins. We reconcile this structuring of oceanic biodiversity using a species-energy framework, with kinetic energy predicting shallow-water richness, while chemical energy (export productivity) and proximity to slope habitats drive deep-sea diversity. Our findings provide a global baseline for conservation efforts across the sea floor, and demonstrate that deep-sea ecosystems show a biodiversity pattern consistent with ecological theory, despite being different from other planetary-scale habitats.

  14. Deep-sea diversity patterns are shaped by energy availability

    NASA Astrophysics Data System (ADS)

    Woolley, Skipton N. C.; Tittensor, Derek P.; Dunstan, Piers K.; Guillera-Arroita, Gurutzeta; Lahoz-Monfort, José J.; Wintle, Brendan A.; Worm, Boris; O'Hara, Timothy D.

    2016-05-01

    The deep ocean is the largest and least-explored ecosystem on Earth, and a uniquely energy-poor environment. The distribution, drivers and origins of deep-sea biodiversity remain unknown at global scales. Here we analyse a database of more than 165,000 distribution records of Ophiuroidea (brittle stars), a dominant component of sea-floor fauna, and find patterns of biodiversity unlike known terrestrial or coastal marine realms. Both patterns and environmental predictors of deep-sea (2,000-6,500 m) species richness fundamentally differ from those found in coastal (0-20 m), continental shelf (20-200 m), and upper-slope (200-2,000 m) waters. Continental shelf to upper-slope richness consistently peaks in tropical Indo-west Pacific and Caribbean (0-30°) latitudes, and is well explained by variations in water temperature. In contrast, deep-sea species show maximum richness at higher latitudes (30-50°), concentrated in areas of high carbon export flux and regions close to continental margins. We reconcile this structuring of oceanic biodiversity using a species-energy framework, with kinetic energy predicting shallow-water richness, while chemical energy (export productivity) and proximity to slope habitats drive deep-sea diversity. Our findings provide a global baseline for conservation efforts across the sea floor, and demonstrate that deep-sea ecosystems show a biodiversity pattern consistent with ecological theory, despite being different from other planetary-scale habitats.

  15. The deep sea is a major sink for microplastic debris

    PubMed Central

    Woodall, Lucy C.; Sanchez-Vidal, Anna; Canals, Miquel; Paterson, Gordon L.J.; Coppock, Rachel; Sleight, Victoria; Calafat, Antonio; Rogers, Alex D.; Narayanaswamy, Bhavani E.; Thompson, Richard C.

    2014-01-01

    Marine debris, mostly consisting of plastic, is a global problem, negatively impacting wildlife, tourism and shipping. However, despite the durability of plastic, and the exponential increase in its production, monitoring data show limited evidence of concomitant increasing concentrations in marine habitats. There appears to be a considerable proportion of the manufactured plastic that is unaccounted for in surveys tracking the fate of environmental plastics. Even the discovery of widespread accumulation of microscopic fragments (microplastics) in oceanic gyres and shallow water sediments is unable to explain the missing fraction. Here, we show that deep-sea sediments are a likely sink for microplastics. Microplastic, in the form of fibres, was up to four orders of magnitude more abundant (per unit volume) in deep-sea sediments from the Atlantic Ocean, Mediterranean Sea and Indian Ocean than in contaminated sea-surface waters. Our results show evidence for a large and hitherto unknown repository of microplastics. The dominance of microfibres points to a previously underreported and unsampled plastic fraction. Given the vastness of the deep sea and the prevalence of microplastics at all sites we investigated, the deep-sea floor appears to provide an answer to the question—where is all the plastic? PMID:26064573

  16. The deep sea is a major sink for microplastic debris.

    PubMed

    Woodall, Lucy C; Sanchez-Vidal, Anna; Canals, Miquel; Paterson, Gordon L J; Coppock, Rachel; Sleight, Victoria; Calafat, Antonio; Rogers, Alex D; Narayanaswamy, Bhavani E; Thompson, Richard C

    2014-12-01

    Marine debris, mostly consisting of plastic, is a global problem, negatively impacting wildlife, tourism and shipping. However, despite the durability of plastic, and the exponential increase in its production, monitoring data show limited evidence of concomitant increasing concentrations in marine habitats. There appears to be a considerable proportion of the manufactured plastic that is unaccounted for in surveys tracking the fate of environmental plastics. Even the discovery of widespread accumulation of microscopic fragments (microplastics) in oceanic gyres and shallow water sediments is unable to explain the missing fraction. Here, we show that deep-sea sediments are a likely sink for microplastics. Microplastic, in the form of fibres, was up to four orders of magnitude more abundant (per unit volume) in deep-sea sediments from the Atlantic Ocean, Mediterranean Sea and Indian Ocean than in contaminated sea-surface waters. Our results show evidence for a large and hitherto unknown repository of microplastics. The dominance of microfibres points to a previously underreported and unsampled plastic fraction. Given the vastness of the deep sea and the prevalence of microplastics at all sites we investigated, the deep-sea floor appears to provide an answer to the question-where is all the plastic?

  17. Deep-Sea Biodiversity in the Mediterranean Sea: The Known, the Unknown, and the Unknowable

    PubMed Central

    Danovaro, Roberto; Company, Joan Batista; Corinaldesi, Cinzia; D'Onghia, Gianfranco; Galil, Bella; Gambi, Cristina; Gooday, Andrew J.; Lampadariou, Nikolaos; Luna, Gian Marco; Morigi, Caterina; Olu, Karine; Polymenakou, Paraskevi; Ramirez-Llodra, Eva; Sabbatini, Anna; Sardà, Francesc; Sibuet, Myriam; Tselepides, Anastasios

    2010-01-01

    Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna) in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth), including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes) reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components investigated

  18. Deep-sea biodiversity in the Mediterranean Sea: the known, the unknown, and the unknowable.

    PubMed

    Danovaro, Roberto; Company, Joan Batista; Corinaldesi, Cinzia; D'Onghia, Gianfranco; Galil, Bella; Gambi, Cristina; Gooday, Andrew J; Lampadariou, Nikolaos; Luna, Gian Marco; Morigi, Caterina; Olu, Karine; Polymenakou, Paraskevi; Ramirez-Llodra, Eva; Sabbatini, Anna; Sardà, Francesc; Sibuet, Myriam; Tselepides, Anastasios

    2010-08-02

    Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna) in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth), including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes) reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components investigated

  19. Ichnology of pelagic carbonate in New Zealand and Denmark: Shelf Sea or Deep Sea

    SciTech Connect

    Ekdale, A.A. )

    1990-05-01

    Today, pelagic carbonate ooze is an exclusive feature of deep-sea environments 1 km or more in depth. In contrast, the extensive epicratonic seas that characterized the Late Cretaceous and early Tertiary received great thicknesses of pelagic carbonate sediment in environments only a few hundred meters deep. Distinguishing between deep-sea and shelf-sea carbonate is not an easy task, but ichnologic investigation helps. Biogenic sedimentary structures, ichnofacies, and ichnofabrics in Cretaceous-Tertiary epicratonic pelagic deposits display many similarities to those in deep-sea sediment. Ichnologic features in shelf-sea chalk and limestone in both New Zealand and northern Europe reveal some interesting paleobathymetric trends. These trends include a general decrease in crustacean traces (Thalassinoides, etc.) and bioerosion traces (Trypanites, etc.) with increasing water depth, accompanied by a concomitant increase in worm burrows (Zoophycos, etc.). Maastrichtian-Oligocene pelaic limestone in New Zealand and Maastrichtian-Paleocene chalk in Denmark neither of which represent a truly deep-sea setting, exhibit similar ichnofacies and ichnofabrics. Some notable differences exist because the New Zealand platform was less extensive and more tectonically active than the northern European shelf. Pelagic strata in New Zealand are associated with shallow-water quartzose sandstone beneath and fossiliferous calcarenite above, as well as deep-water bedded chert within, the pelagic carbonate sequence. In New Zealand strata Zoophycos-rich facies dominate Thalassinoides-rich facies, and bored hardgrounds are uncommon; in Danish chalk sequences the opposite is true in both cases.

  20. First biological measurements of deep-sea corals from the Red Sea

    PubMed Central

    Roder, C.; Berumen, M. L.; Bouwmeester, J.; Papathanassiou, E.; Al-Suwailem, A.; Voolstra, C. R.

    2013-01-01

    It is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with ‘deep-sea’ and ‘cold-water’ corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red Sea but occurs in deep cold waters outside the Red Sea raising interesting questions about presumed environmental constraints for other deep-sea corals. Our findings suggest that the present understanding of deep-sea coral persistence and resilience needs to be revisited. PMID:24091830

  1. Orbital forcing of deep-sea benthic species diversity

    USGS Publications Warehouse

    Cronin, T. M.; Raymo, M.E.

    1997-01-01

    Explanations for the temporal and spatial patterns of species biodiversity focus on stability-time, disturbance-mosaic (biogenic microhabitat heterogeneity) and competition-predation (biotic interactions) hypotheses. The stability-time hypothesis holds that high species diversity in the deep sea and in the tropics reflects long-term climatic stability. But the influence of climate change on deep-sea diversity has not been studied and recent evidence suggests that deep-sea environments undergo changes in climatically driven temperature and flux of nutrients and organic-carbon during glacial-interglacial cycles. Here we show that Pliocene (2.85-2.40 Myr) deep-sea North Atlantic benthic ostracod (Crustacea) species diversity is related to solar insolation changes caused by 41,000-yr cycles of Earth's obliquity (tilt). Temporal changes in diversity, as measured by the Shannon- Weiner index, H(S), correlate with independent climate indicators of benthic foraminiferal oxygen-isotope ratios (mainly ice volume) and ostracod Mg:Ca ratios (bottomwater temperature). During glacial periods, H(S) = 0.2-0.6, whereas during interglacials, H(S) = 1.2-1.6, which is three to four times as high. The control of deep-sea benthic diversity by cyclic climate change at timescales of 103-104 yr does not support the stability-time hypothesis because it shows that the deep sea is a temporally dynamic environment. Diversity oscillations reflect large-scale response of the benthic community to climatically driven changes in either thermohaline circulation, bottom temperature (or temperature-related factors) and food, and a coupling of benthic diversity to surface productivity.

  2. Species distribution models of tropical deep-sea snappers.

    PubMed

    Gomez, Céline; Williams, Ashley J; Nicol, Simon J; Mellin, Camille; Loeun, Kim L; Bradshaw, Corey J A

    2015-01-01

    Deep-sea fisheries provide an important source of protein to Pacific Island countries and territories that are highly dependent on fish for food security. However, spatial management of these deep-sea habitats is hindered by insufficient data. We developed species distribution models using spatially limited presence data for the main harvested species in the Western Central Pacific Ocean. We used bathymetric and water temperature data to develop presence-only species distribution models for the commercially exploited deep-sea snappers Etelis Cuvier 1828, Pristipomoides Valenciennes 1830, and Aphareus Cuvier 1830. We evaluated the performance of four different algorithms (CTA, GLM, MARS, and MAXENT) within the BIOMOD framework to obtain an ensemble of predicted distributions. We projected these predictions across the Western Central Pacific Ocean to produce maps of potential deep-sea snapper distributions in 32 countries and territories. Depth was consistently the best predictor of presence for all species groups across all models. Bathymetric slope was consistently the poorest predictor. Temperature at depth was a good predictor of presence for GLM only. Model precision was highest for MAXENT and CTA. There were strong regional patterns in predicted distribution of suitable habitat, with the largest areas of suitable habitat (> 35% of the Exclusive Economic Zone) predicted in seven South Pacific countries and territories (Fiji, Matthew & Hunter, Nauru, New Caledonia, Tonga, Vanuatu and Wallis & Futuna). Predicted habitat also varied among species, with the proportion of predicted habitat highest for Aphareus and lowest for Etelis. Despite data paucity, the relationship between deep-sea snapper presence and their environments was sufficiently strong to predict their distribution across a large area of the Pacific Ocean. Our results therefore provide a strong baseline for designing monitoring programs that balance resource exploitation and conservation planning, and

  3. Species Distribution Models of Tropical Deep-Sea Snappers

    PubMed Central

    Gomez, Céline; Williams, Ashley J.; Nicol, Simon J.; Mellin, Camille; Loeun, Kim L.; Bradshaw, Corey J. A.

    2015-01-01

    Deep-sea fisheries provide an important source of protein to Pacific Island countries and territories that are highly dependent on fish for food security. However, spatial management of these deep-sea habitats is hindered by insufficient data. We developed species distribution models using spatially limited presence data for the main harvested species in the Western Central Pacific Ocean. We used bathymetric and water temperature data to develop presence-only species distribution models for the commercially exploited deep-sea snappers Etelis Cuvier 1828, Pristipomoides Valenciennes 1830, and Aphareus Cuvier 1830. We evaluated the performance of four different algorithms (CTA, GLM, MARS, and MAXENT) within the BIOMOD framework to obtain an ensemble of predicted distributions. We projected these predictions across the Western Central Pacific Ocean to produce maps of potential deep-sea snapper distributions in 32 countries and territories. Depth was consistently the best predictor of presence for all species groups across all models. Bathymetric slope was consistently the poorest predictor. Temperature at depth was a good predictor of presence for GLM only. Model precision was highest for MAXENT and CTA. There were strong regional patterns in predicted distribution of suitable habitat, with the largest areas of suitable habitat (> 35% of the Exclusive Economic Zone) predicted in seven South Pacific countries and territories (Fiji, Matthew & Hunter, Nauru, New Caledonia, Tonga, Vanuatu and Wallis & Futuna). Predicted habitat also varied among species, with the proportion of predicted habitat highest for Aphareus and lowest for Etelis. Despite data paucity, the relationship between deep-sea snapper presence and their environments was sufficiently strong to predict their distribution across a large area of the Pacific Ocean. Our results therefore provide a strong baseline for designing monitoring programs that balance resource exploitation and conservation planning, and

  4. Ecosystem function and services provided by the deep sea

    NASA Astrophysics Data System (ADS)

    Thurber, A. R.; Sweetman, A. K.; Narayanaswamy, B. E.; Jones, D. O. B.; Ingels, J.; Hansman, R. L.

    2014-07-01

    The deep sea is often viewed as a vast, dark, remote, and inhospitable environment, yet the deep ocean and seafloor are crucial to our lives through the services that they provide. Our understanding of how the deep sea functions remains limited, but when treated synoptically, a diversity of supporting, provisioning, regulating and cultural services becomes apparent. The biological pump transports carbon from the atmosphere into deep-ocean water masses that are separated over prolonged periods, reducing the impact of anthropogenic carbon release. Microbial oxidation of methane keeps another potent greenhouse gas out of the atmosphere while trapping carbon in authigenic carbonates. Nutrient regeneration by all faunal size classes provides the elements necessary for fueling surface productivity and fisheries, and microbial processes detoxify a diversity of compounds. Each of these processes occur on a very small scale, yet considering the vast area over which they occur they become important for the global functioning of the ocean. The deep sea also provides a wealth of resources, including fish stocks, enormous bioprospecting potential, and elements and energy reserves that are currently being extracted and will be increasingly important in the near future. Society benefits from the intrigue and mystery, the strange life forms, and the great unknown that has acted as a muse for inspiration and imagination since near the beginning of civilization. While many functions occur on the scale of microns to meters and timescales up to years, the derived services that result are only useful after centuries of integrated activity. This vast dark habitat, which covers the majority of the globe, harbors processes that directly impact humans in a variety of ways; however, the same traits that differentiate it from terrestrial or shallow marine systems also result in a greater need for integrated spatial and temporal understanding as it experiences increased use by society. In

  5. Abrupt climate change and collapse of deep-sea ecosystems

    USGS Publications Warehouse

    Yasuhara, Moriaki; Cronin, T. M.; Demenocal, P.B.; Okahashi, H.; Linsley, B.K.

    2008-01-01

    We investigated the deep-sea fossil record of benthic ostracodes during periods of rapid climate and oceanographic change over the past 20,000 years in a core from intermediate depth in the northwestern Atlantic. Results show that deep-sea benthic community "collapses" occur with faunal turnover of up to 50% during major climatically driven oceanographic changes. Species diversity as measured by the Shannon-Wiener index falls from 3 to as low as 1.6 during these events. Major disruptions in the benthic communities commenced with Heinrich Event 1, the Inter-Aller??d Cold Period (IACP: 13.1 ka), the Younger Dryas (YD: 12.9-11.5 ka), and several Holocene Bond events when changes in deep-water circulation occurred. The largest collapse is associated with the YD/IACP and is characterized by an abrupt two-step decrease in both the upper North Atlantic Deep Water assemblage and species diversity at 13.1 ka and at 12.2 ka. The ostracode fauna at this site did not fully recover until ???8 ka, with the establishment of Labrador Sea Water ventilation. Ecologically opportunistic slope species prospered during this community collapse. Other abrupt community collapses during the past 20 ka generally correspond to millennial climate events. These results indicate that deep-sea ecosystems are not immune to the effects of rapid climate changes occurring over centuries or less. ?? 2008 by The National Academy of Sciences of the USA.

  6. Abrupt climate change and collapse of deep-sea ecosystems.

    PubMed

    Yasuhara, Moriaki; Cronin, Thomas M; Demenocal, Peter B; Okahashi, Hisayo; Linsley, Braddock K

    2008-02-05

    We investigated the deep-sea fossil record of benthic ostracodes during periods of rapid climate and oceanographic change over the past 20,000 years in a core from intermediate depth in the northwestern Atlantic. Results show that deep-sea benthic community "collapses" occur with faunal turnover of up to 50% during major climatically driven oceanographic changes. Species diversity as measured by the Shannon-Wiener index falls from 3 to as low as 1.6 during these events. Major disruptions in the benthic communities commenced with Heinrich Event 1, the Inter-Allerød Cold Period (IACP: 13.1 ka), the Younger Dryas (YD: 12.9-11.5 ka), and several Holocene Bond events when changes in deep-water circulation occurred. The largest collapse is associated with the YD/IACP and is characterized by an abrupt two-step decrease in both the upper North Atlantic Deep Water assemblage and species diversity at 13.1 ka and at 12.2 ka. The ostracode fauna at this site did not fully recover until approximately 8 ka, with the establishment of Labrador Sea Water ventilation. Ecologically opportunistic slope species prospered during this community collapse. Other abrupt community collapses during the past 20 ka generally correspond to millennial climate events. These results indicate that deep-sea ecosystems are not immune to the effects of rapid climate changes occurring over centuries or less.

  7. Development and Evaluation of Deep-Sea Swimsuit Materials.

    DTIC Science & Technology

    1973-06-01

    great sea depths for long periods of time . Two chemically distinct, flexible, syntactic foams--a Unit-developed, polyurethane, hollow-glass-microsphere...applications in deep-sea environments down to 1000 FSW. Tests showed that both materials were essentially incompressible to depths of 1000 FSW (less than 3...verification of sample thermal-conductivity data. Suit conductivity tests performed on an instrumented copper manikin substantially confirmed the

  8. Characterization of Deep Sea Fish Gut Bacteria with Antagonistic Potential, from Centroscyllium fabricii (Deep Sea Shark).

    PubMed

    Bindiya, E S; Tina, K J; Raghul, Subin S; Bhat, Sarita G

    2015-06-01

    The bacterial isolates from Centroscyllium fabricii (deep sea shark) gut were screened for antagonistic activity by cross-streak method and disc diffusion assay. This study focuses on strain BTSS-3, which showed antimicrobial activity against pathogenic bacteria including Salmonella Typhimurium, Proteus vulgaris, Clostridium perfringens, Staphylococcus aureus, Bacillus cereus, Bacillus circulans, Bacillus macerans and Bacillus pumilus. BTSS3 was subjected to phenotypic characterization using biochemical tests, SEM imaging, exoenzyme profiling and antibiotic susceptibility tests. Comparative 16S rDNA gene sequence analysis indicated that this strain belonged to the genus Bacillus, with high (98%) similarity to 16S rDNA sequences of Bacillus amyloliquefaciens. The chemical nature of the antibacterial substance was identified by treatment with proteolytic enzymes. The antibacterial activity was reduced by the action of these enzymes pointing out its peptide nature. It was observed from the growth and production kinetics that the bacteriocin was produced in the eighth hour of incubation, i.e., during the mid-log growth phase of the bacteria.

  9. Analytical calculation of muon intensities under deep sea-water

    NASA Technical Reports Server (NTRS)

    Inazawa, H.; Kobayakawa, K.

    1985-01-01

    The study of the energy loss of high energy muons through different materials, such as rock and sea-water can cast light on characteristics of lepton interactions. There are less ambiguities for the values of atomic number (Z) and mass number (A) in sea-water than in rock. Muon intensities should be measured as fundamental data and as background data for searching the fluxes of neutrino. The average range energy relation in sea-water is derived. The correction factors due to the range fluctuation is also computed. By applying these results, the intensities deep under sea are converted from a given muon energy spectra at sea-level. The spectra of conventional muons from eta, K decays have sec theta enhancement. The spectrum of prompt muons from charmed particles is almost isotropic. The effect of prompt muons is examined.

  10. Using near infrared light for deep sea mining observation systems

    NASA Astrophysics Data System (ADS)

    Lu, Huimin; Li, Yujie; Li, Xin; Yang, Jianmin; Serikawa, Seiichi

    2015-10-01

    In this paper, we design a novel deep-sea near infrared light based imaging equipment for deep-sea mining observation systems. The spectral sensitivity peaks are in the red region of the invisible spectrum, ranging from 750nm to 900nm. In addition, we propose a novel underwater imaging model that compensates for the attenuation discrepancy along the propagation path. The proposed model fully considered the effects of absorption, scattering and refraction. We also develop a locally adaptive Laplacian filtering for enhancing underwater transmission map after underwater dark channel prior estimation. Furthermore, we propose a spectral characteristic-based color correction algorithm to recover the distorted color. In water tank experiments, we made a linear scale of eight turbidity steps ranging from clean to heavily scattered by adding deep sea soil to the seawater (from 500 to 2000 mg/L). We compared the results of different turbidity underwater scene, illuminated alternately with near infrared light vs. white light. Experiments demonstrate that the enhanced NIR images have a reasonable noise level after the illumination compensation in the dark regions and demonstrates an improved global contrast by which the finest details and edges are significantly enhanced. We also demonstrate that the effective distance of the designed imaging system is about 1.5 meters, which can meet the requirement of micro-terrain observation around the deep-sea mining systems. Remotely Operated Underwater Vehicle (ROV)-based experiments also certified the effectiveness of the proposed method.

  11. Deep-sea primary production at the Galapagos hydrothermal vents

    SciTech Connect

    Karl, D.M.; Wirsen, C.O.; Jannasch, H.W.

    1980-03-21

    Dense animal populations surrounding recently discovered hydrothermal vents at the Galapagos Rift sea-floor spreading center, 2550 meters deep, are probably sustained by microbial primary production. Energy in the form of geothermically reduced sulfur compounds emitted from the vents is liberated during oxidation and used for the reduction of carbon dioxide to organic matter by chemosynthetic bacteria.

  12. Antarctic marine biodiversity and deep-sea hydrothermal vents.

    PubMed

    Chown, Steven L

    2012-01-01

    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 hydrothermal vents. Vent ecosystems have been documented from many sites 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 vent ecosystems are very different to those elsewhere, though the microbiota, which form the basis of vent food webs, show less differentiation. Much of the biological significance of deep-sea hydrothermal vents 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 hydrothermal vent ecosystems provides opportunities for new understanding in these fields. Moreover, the Antarctic vents 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 hydrothermal vents located in international waters are not protected and may be threatened by growing interests in deep-sea mining.

  13. Potential biomass in deep-sea hydrothermal vent ecosystem

    NASA Astrophysics Data System (ADS)

    Nakamura, K.; Takai, K.

    2012-12-01

    Since the first discovery of black smoker vents hosting chemosynthetic macrofaunal communities (Spiess et al., 1980), submarine hydrothermal 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 hydrothermal vent-endemic animal communities as the primary producer. This type of microorganisms obtains energy from inorganic substances (e.g., sulfur, hydrogen, and methane) derived from hydrothermal vent 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 hydrothermal vent ecosystem is largely unknown. Here, we present geophysical and geochemical constraints on potential biomass in the deep-sea hydrothermal vent ecosystem. The estimation of the potential biomass in the deep-sea hydrothermal vent ecosystem is based on hydrothermal fluid flux calculated from heat flux (Elderfield and Schltz, 1996), maximum chemical energy available from metabolic reactions during mixing between hydrothermal vent 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 hydrothermal vent 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 hydrothermal vent ecosystem is calculated to be much smaller than that in terrestrial ecosystems including terrestrial plants. The big difference in biomass between the

  14. Possible Sea Ice Impacts on Oceanic Deep Convection

    NASA Technical Reports Server (NTRS)

    Parkinson, C. L.

    1984-01-01

    Many regions of the world ocean known or suspected to have deep convection are sea-ice covered for at least a portion of the annual cycle. As this suggests that sea ice might have some impact on generating or maintaining this phenomenon, several mechanisms by which sea ice could exert an influence are presented in the following paragraphs. Sea ice formation could be a direct causal factor in deep convection by providing the surface density increase necessary to initiate the convective overturning. As sea ice forms, either by ice accretion or by in situ ice formation in open water or in lead areas between ice floes, salt is rejected to the underlying water. This increases the water salinity, thereby increasing water density in the mixed layer under the ice. A sufficient increase in density will lead to mixing with deeper waters, and perhaps to deep convection or even bottom water formation. Observations are needed to establish whether this process is actually occurring; it is most likely in regions with extensive ice formation and a relatively unstable oceanic density structure.

  15. Plastic microfibre ingestion by deep-sea organisms

    NASA Astrophysics Data System (ADS)

    Taylor, M. L.; Gwinnett, C.; Robinson, L. F.; Woodall, L. C.

    2016-09-01

    Plastic waste is a distinctive indicator of the world-wide impact of anthropogenic activities. Both macro- and micro-plastics are found in the ocean, but as yet little is known about their ultimate fate and their impact on marine ecosystems. In this study we present the first evidence that microplastics are already becoming integrated into deep-water organisms. By examining organisms that live on the deep-sea floor we show that plastic microfibres are ingested and internalised by members of at least three major phyla with different feeding mechanisms. These results demonstrate that, despite its remote location, the deep sea and its fragile habitats are already being exposed to human waste to the extent that diverse organisms are ingesting microplastics.

  16. Plastic microfibre ingestion by deep-sea organisms

    PubMed Central

    Taylor, M. L.; Gwinnett, C.; Robinson, L. F.; Woodall, L. C.

    2016-01-01

    Plastic waste is a distinctive indicator of the world-wide impact of anthropogenic activities. Both macro- and micro-plastics are found in the ocean, but as yet little is known about their ultimate fate and their impact on marine ecosystems. In this study we present the first evidence that microplastics are already becoming integrated into deep-water organisms. By examining organisms that live on the deep-sea floor we show that plastic microfibres are ingested and internalised by members of at least three major phyla with different feeding mechanisms. These results demonstrate that, despite its remote location, the deep sea and its fragile habitats are already being exposed to human waste to the extent that diverse organisms are ingesting microplastics. PMID:27687574

  17. Law of the sea: Deep-ocean mining

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    It has taken 14 years for the Law of the Sea Convention to adopt an agreement to control and regulate activities by nations on the world's ocean floors. Of particular concern to the United States was the subject of deep ocean mining; adoption of the convention's draft was voted on at United Nations headquarters this past April 30th (see Eos, June 1, p. 523). The United States voted not to adopt the draft; the Reagan administration announced that the President will not sign the Law of the Sea Convention later this year when it is opened for signature in Caracas, Venezuela. There is a lot at stake from the standpoint of both the need for strategic metals, such as manganese, that exist on the deep-ocean floor and the protection of the technology of ocean-floor mining. Regulations on deep-ocean mining practices could threaten the interests of the major nations.

  18. Diverse deep-sea fungi from the South China Sea and their antimicrobial activity.

    PubMed

    Zhang, Xiao-Yong; Zhang, Yun; Xu, Xin-Ya; Qi, Shu-Hua

    2013-11-01

    We investigated the diversity of fungal communities in nine different deep-sea sediment samples of the South China Sea by culture-dependent methods followed by analysis of fungal internal transcribed spacer (ITS) sequences. Although 14 out of 27 identified species were reported in a previous study, 13 species were isolated from sediments of deep-sea environments for the first report. Moreover, these ITS sequences of six isolates shared 84-92 % similarity with their closest matches in GenBank, which suggested that they might be novel phylotypes of genera Ajellomyces, Podosordaria, Torula, and Xylaria. The antimicrobial activities of these fungal isolates were explored using a double-layer technique. A relatively high proportion (56 %) of fungal isolates exhibited antimicrobial activity against at least one pathogenic bacterium or fungus among four marine pathogenic microbes (Micrococcus luteus, Pseudoaltermonas piscida, Aspergerillus versicolor, and A. sydowii). Out of these antimicrobial fungi, the genera Arthrinium, Aspergillus, and Penicillium exhibited antibacterial and antifungal activities, while genus Aureobasidium displayed only antibacterial activity, and genera Acremonium, Cladosporium, Geomyces, and Phaeosphaeriopsis displayed only antifungal activity. To our knowledge, this is the first report to investigate the diversity and antimicrobial activity of culturable deep-sea-derived fungi in the South China Sea. These results suggest that diverse deep-sea fungi from the South China Sea are a potential source for antibiotics' discovery and further increase the pool of fungi available for natural bioactive product screening.

  19. Controls on the distribution of deep-sea sediments

    NASA Astrophysics Data System (ADS)

    Dutkiewicz, A.; O'Callaghan, S.; Müller, R. D.

    2016-08-01

    Deep-sea sediments represent the largest geological deposit on Earth and provide a record of our planet's response to conditions at the sea surface from where the bulk of material originates. We use a machine learning method to analyze how the distribution of 14,400 deep-sea sediment sample lithologies is connected to bathymetry and surface oceanographic parameters. Our probabilistic Gaussian process classifier shows that the geographic occurrence of five major lithologies in the world's ocean can be predicted using just three parameters. Sea-surface salinity and temperature provide a major control for the growth and composition of plankton and specific ranges are also associated with the influx of non-aerosol terrigenous material into the ocean, while bathymetry is an important parameter for discriminating the occurrence of calcareous sediment, clay and coarse lithogenous sediment from each other. We find that calcareous and siliceous oozes are not linked to high surface productivity. Diatom and radiolarian oozes are associated with low salinities at the surface but with discrete ranges of temperatures, reflecting the diversity of planktonic species in different climatic zones. Biosiliceous sediments cannot be used to infer paleodepth, but are good indicators of paleotemperature and paleosalinity. Our analysis provides a new framework for constraining paleosurface ocean environments from the geological record of deep-sea sediments. It shows that small shifts in salinity and temperature significantly affect the lithology of seafloor sediment. As deep-sea sediments represent the largest carbon sink on Earth these shifts need to be considered in the context of global ocean warming.

  20. 46 CFR 167.40-20 - Deep-sea sounding apparatus.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Deep-sea sounding apparatus. 167.40-20 Section 167.40-20... SHIPS Certain Equipment Requirements § 167.40-20 Deep-sea sounding apparatus. Nautical school ships shall be equipped with an efficient or electronic deep-sea sounding apparatus. The electronic...

  1. 46 CFR 167.40-20 - Deep-sea sounding apparatus.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Deep-sea sounding apparatus. 167.40-20 Section 167.40-20... SHIPS Certain Equipment Requirements § 167.40-20 Deep-sea sounding apparatus. Nautical school ships shall be equipped with an efficient or electronic deep-sea sounding apparatus. The electronic...

  2. 46 CFR 167.40-20 - Deep-sea sounding apparatus.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Deep-sea sounding apparatus. 167.40-20 Section 167.40-20... SHIPS Certain Equipment Requirements § 167.40-20 Deep-sea sounding apparatus. Nautical school ships shall be equipped with an efficient or electronic deep-sea sounding apparatus. The electronic...

  3. 77 FR 35850 - Safety Zone; F/V Deep Sea, Penn Cove, WA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; F/V Deep Sea, Penn Cove, WA AGENCY: Coast... the Fishing Vessel (F/V) Deep Sea, located in Penn Cove, WA. This action is necessary to ensure the... materials associated with the sunken F/V Deep Sea. B. Basis and Purpose On the evening of May 13, 2012,...

  4. 75 FR 49420 - Fisheries of the Northeastern United States; Atlantic Deep-Sea Red Crab Fisheries; 2010 Atlantic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-13

    ... United States; Atlantic Deep-Sea Red Crab Fisheries; 2010 Atlantic Deep-Sea Red Crab Specifications In... (TAC) and corresponding fleet days-at-sea (DAS) allocation for the Atlantic deep- sea red crab fishery... the implementing regulations for the Atlantic Deep- Sea Red Crab Fishery Management Plan...

  5. Global deep-sea extinctions during the Pleistocene ice ages

    NASA Astrophysics Data System (ADS)

    Hayward, Bruce W.

    2001-07-01

    The dark, near-freezing environment of the deep oceans is regarded as one of the most stable habitats on Earth, and this stability is generally reflected in the slow turnover rates (extinctions and appearances) of the organisms that live there. By far the best fossil record of deep-sea organisms is provided by the shells of benthic foraminifera (Protista). A little-known global extinction of deep-sea benthic foraminifera occurred during the Pleistocene ice ages. In the southwest Pacific, it caused the disappearance of at least two families, 15 genera, and 48 species (˜15% 25% of the fauna) of dominantly uniserial, elongate foraminifera with distinctive apertural modifications. These forms progressively died back and became extinct during glacial periods in the late Pliocene to middle Pleistocene (ca. 2.5 0.6 Ma); most extinctions occurred between 1.0 and 0.6 Ma, at the time of the middle Pleistocene climatic revolution. This first high-resolution study of this extinction event indicates that it was far more significant for deep-sea diversity loss than previously reported (10 species). The middle Pleistocene extinction was the most dramatic last phase of a worldwide decline in the abundance of these elongate forms, a phase that began during cooling near the Eocene-Oligocene boundary and continued during the middle Miocene. Clearly these taxa declined when the world cooled, but the reason is yet to be resolved.

  6. Pleistocene Deep Sea ostracods from the Bering Sea (IODP expedition 323)

    NASA Astrophysics Data System (ADS)

    Alvarez Zarikian, Carlos A.

    2016-03-01

    The study presents the first Pleistocene (0-1.9 Ma) record of Deep Sea ostracods from the Bering Sea, derived primarily from Integrated Ocean Drilling Program Expedition 323, Site U1344 (59°3.0‧N, 179°12.2‧W, 3171 m of water depth). Deep Sea ostracod abundances in the Bering Sea sediments are some of the lowest that have been recorded in bathyal and abyssal marine environments (<1 specimen per sediment gram). In comparison, benthic foraminifera are several orders of magnitude more abundant in the same samples. The humble ostracod assemblage at Site U1344 is predominantly composed of deep water species Krithe sawanensis, Fallacihowella sp. A, Cytheropteron spp., Eucytherura sp., Argilloecia toyamaensis, and Bradleya mesembrina. Less abundant taxa include Munseyella melzeri, Munseyella ristveti, Cluthia sp., Robertsonites hanaii, and Microcythere mediostriata. Some of these taxa (e.g. Fallacihowella sp. A, Bradleya mesembrina, Microcythere mediostriata) are reported for the first time in the North Pacific. The predominance of the genera Krithe, Fallacihowella, Cytheropteron and Argilloecia indicates cold, ventilated bottom waters. The deep Bering Sea ostracod assemblage shares many common and closely related species with continental slope faunas from the Gulf of Alaska, the Okhotsk Sea, the Arctic Ocean, and even the subpolar North Atlantic. A few continental shelf ostracods, such as species of Munseyella and Robertsonites, are present at Sites U1344 and U1343, in the northern slope of the Aleutian Basin. The presence of shallow water ostracods at the Bering Sea slope sites is possibly explained by sea ice rafting. Exceptionally low ostracod abundance in the U1344 record did not permit evaluating links between ostracod faunas and paleoceanographic conditions; however, an increase in ostracod occurrences throughout the middle Pleistocene at Site U1344 appears to correlate with general sea ice expansion in the Bering Sea. High primary surface productivity, high

  7. Practical application of a sea-water battery in deep-sea basin and its performance

    NASA Astrophysics Data System (ADS)

    Shinohara, Masanao; Araki, Eiichiro; Mochizuki, Masashi; Kanazawa, Toshihiko; Suyehiro, Kiyoshi

    Stable power supply is essential for various long-term sea floor geophysical observations. Due to a simple structure and a large energy capacity, sea-water batteries have been developed and used for such observations. However, the characteristics of sea-water batteries have not been well known in the case of installations at depths more than 5000 m in deep-sea basin. In 2000, a sea floor borehole broadband seismic observatory was installed in the northwestern Pacific basin where the water depth is 5577 m. For electric power supply, a Sea-Water Battery (SWB) system with monitoring and control was developed and used. The SWB system consists of four sea-water battery cells, a DC/DC converter, the Power Control System, the Data Logger, and an accumulator. The conditions of the SWB system were recorded more than 1 year, and the monitoring data was recovered. The SWB system generated enough power for the observation system consuming power of 6 W in average and continued to supply power for at least 5 years. From the monitoring data, the SWB can supply up to the long-term average of at least 13 W. The energy density is estimated to be 318 Wh kg -1. The sea-water battery is useful for application of long-term power consumption even in the deep-sea basin.

  8. Sediment reworking rates in deep sediments of the Mediterranean Sea.

    PubMed

    Barsanti, M; Delbono, I; Schirone, A; Langone, L; Miserocchi, S; Salvi, S; Delfanti, R

    2011-07-01

    Different pelagic areas of the Mediterranean Sea have been investigated in order to quantify physical and biological mixing processes in deep sea sediments. Herein, results of eleven sediment cores sampled at different deep areas (> 2000 m) of the Western and Eastern Mediterranean Sea are presented. ²¹⁰Pb(xs) and ¹³⁷Cs vertical profiles, together with ¹⁴C dating, are used to identify the main processes characterising the different areas and, finally, controlling mixing depths (SML) and bioturbation coefficients (D(b)). Radionuclide vertical profiles and inventories indicate that bioturbation processes are the dominant processes responsible for sediment reworking in deep sea environments. Results show significant differences in sediment mixing depths and bioturbation coefficients among areas of the Mediterranean Sea characterised by different trophic regimes. In particular, in the Oran Rise area, where the Almeria-Oran Front induces frequent phytoplankton blooms, we calculate the highest values of sediment mixing layers (13 cm) and bioturbation coefficients (0.187 cm² yr⁻¹), and the highest values of ²¹⁰Pb(xs) and ¹³⁷Cs inventories. Intermediate values of SML and D(b) (~6 cm and ~0.040 cm² yr⁻¹, respectively) characterise the mesothrophic Algero-Balearic basin, while in the Southern Tyrrhenian Sea mixing parameters (SML of 3 cm and D(b) of 0.011 cm² yr⁻¹ are similar to those calculated for the oligotrophic Eastern Mediterranean (SML of 2 cm and D(b) of ~0.005 cm² yr⁻¹).

  9. Risk assessment of a deep sea pipeline

    SciTech Connect

    Egan, G.R.; Zebroski, E.L.; Kaplan, S.

    1996-12-31

    A unique design of subsea gas pipeline has been under consideration for several years. It would traverse the Arabian Sea for 1,100 kilometers with a large part of it at depths over 3,000 meters and temperatures near 2 C. A Probabilistic Risk Analysis has been performed with special attention to the novel technical features of the design, construction and operating environments. The factors considered to date have included: pipe and materials design for internal pressures to 500 bar and external pressures to 430 bar, laydown processes, materials quality and QA/QC, piping stress and strain levels in laydown and spans, route selection, and other factors. The methods used to screen, rank, and quantify the risks are described. The scenarios involving the principal hazards are described and the risks are quantified. Options for further risk control and reduction measures are also identified. The results at this stage show relatively low expected values for the principal risks. Assuming effective implementation of the available control measures, the proposed design is calculated to have risk levels lower than the historical average for similar mega-projects.

  10. Deep Sea Benthic Foraminifera: Love Cold, Fear Warm

    NASA Astrophysics Data System (ADS)

    Thomas, E.

    2007-12-01

    The fossil record provides understanding of possible linkages between long-term environmental changes and evolution of assemblages and morphological species of deep-sea benthic foraminifera, of which the phylogeny is still little known. Deep-sea benthic foraminifera have long morphological species lives and do not commonly suffer massive extinctions: they live in the largest habitat on earth, species have large geographic ranges or are cosmopolitan, and they use motile propagules to rapidly re-populate regions where populations have been destroyed. Extinction occurs only when rapid and severe environmental change affects such a large part of the deep ocean that no refugia exist, even for common species. Deep-sea benthic foraminifera reacted to global cooling (in the earliest Oligocene, middle Miocene and middle Pleistocene) not by extinction, but by a gradual turnover of species. The most extensive turnover occurred in the late Eocene through earliest Oligocene, when some presently important ecological niches were first filled. In contrast, deep-sea benthic foraminifera suffered severe extinction (30-50% of species, including common, cosmopolitan, long-lived species) during the rapid global warming of the Paleocene-Eocene Thermal Maximum (PETM), a time of high CO2 levels and potential ocean acidification. The extinction was followed by slow recovery of faunas, but diversity never returned to pre-extinction levels. The PETM and later, less severe short-term periods of global warming (hyperthermals ETM1 and ETM2) were characterized by low diversity faunas dominated by small, thin-walled individuals. No significant net extinction occurred during the later hyperthermals. Such faunas might reflect dissolution, low oxygen conditions, or blooming of opportunistic species after environmental disturbance. Most commonly cited causes of the PETM extinction are: 1. low oxygen concentrations, 2. acidification of the oceans, 3. increase or decrease in oceanic productivity and

  11. Biofilm transplantation in the deep sea.

    PubMed

    Wagner-Döbler, Irene

    2016-05-01

    A gold rush is currently going on in microbial ecology, which is powered by the possibility to determine the full complexity of microbial communities through next-generation sequencing. Accordingly, enormous efforts are underway to describe microbiomes worldwide, in humans, animals, plants, soil, air and the ocean. While much can be learned from these studies, only experiments will finally unravel mechanisms. One of the key questions is how a microbial community is assembled from a pool of bacteria in the environment, and how it responds to change - be it the increase in CO2 concentration in the ocean, or antibiotic treatment of the gut microbiome. The study by Zhang et al. () in this issue is one of the very few that approaches this problem experimentally in the natural environment. The authors selected a habitat which is both extremely interesting and difficult to access. They studied the Thuwal Seep in the Red Sea at 850 m depth and used a remotely operated vehicle (ROV) to place a steel frame carrying substrata for biofilm growth into the brine pool and into the adjacent normal bottom water (NBW). Biofilms were allowed to develop for 3 days, and then those that had been growing in the brine pool were transported to normal bottom water and stayed there for another 3 days, and vice versa. The 'switched' biofilms were then compared with their source communities by metagenome sequencing. Strikingly, both 'switched' biofilms were now dominated by the same two species. These species were able to cope with conditions in both source ecosystems, as shown by assembly of their genomes and detection of expression of key genes. The biofilms had adapted to environmental change, rather than to brine pools or NBW. The study shows both the resilience and adaptability of biofilm communities and has implications for microbial ecology in general and even for therapeutic approaches such as transplantation of faecal microbiomes.

  12. Food web structure and vulnerability of a deep-sea ecosystem in the NW Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Tecchio, Samuele; Coll, Marta; Christensen, Villy; Company, Joan B.; Ramírez-Llodra, Eva; Sardà, Francisco

    2013-05-01

    There is increasing fishing pressure on the continental margins of the oceans, and this raises concerns about the vulnerability of the ecosystems thriving there. The current knowledge of the biology of deep-water fish species identifies potential reduced resilience to anthropogenic disturbance. However, there are extreme difficulties in sampling the deep sea, resulting in poorly resolved and indirectly obtained food-web relationships. Here, we modelled the flows and biomasses of a Mediterranean deep-sea ecosystem, the Catalan Sea continental slope at depths of 1000-1400 m. This is the first model of a deep-water ecosystem in the Mediterranean Sea. The objectives were to (a) quantitatively describe the food web structure of the ecosystem, (b) examine the role of key species in the ecosystem, and (c) explore the vulnerability of this deep-sea ecosystem to potential future fishing exploitation. We used the Ecopath with Ecosim (EwE) modelling approach and software to model the ecosystem. The trophic model included 18 consumers, a marine snow group, and a sediment detritus group. Trophic network analysis identified low levels of consumer biomass cycling and low system omnivory index when compared with expected values of marine ecosystems, and higher cycling and omnivory when compared with available EwE models of shallower areas of the Mediterranean Sea. The majority of flows in the ecosystem were concentrated at the trophic level of first-order consumers (TL 2). Benthic invertebrates and demersal sharks were identified to have key ecological roles in the ecosystem. We used the dynamic temporal model Ecosim to simulate expansion of the red-shrimp benthic trawl fishery that currently operates at shallower depths, down to 800 m depth. The simulations showed reductions in fish biomass and that the state of the deep continental slope ecosystem in the western Mediterranean seems to be the result of a long-term succession process, which has reached ecological stability, and is

  13. The deep-sea hub of the ANTARES neutrino telescope

    NASA Astrophysics Data System (ADS)

    Anghinolfi, M.; Calzas, A.; Dinkespiler, B.; Cuneo, S.; Favard, S.; Hallewell, G.; Jaquet, M.; Musumeci, M.; Papaleo, R.; Raia, G.; Valdy, P.; Vernin, P.

    2006-11-01

    The ANTARES neutrino telescope, currently under construction at 2500 m depth off the French Mediterranean coast, will contain 12 detection lines, powered and read out through a deep-sea junction box (JB) hub. Electrical energy from the shore station is distributed through a transformer with multiple secondary windings and a plugboard with 16 deep sea-mateable electro-optic connectors. Connections are made to the JB outputs using manned or remotely operated submersible vehicles. The triply redundant power management and slow control system is based on two identical AC-powered systems, communicating with the shore through 160 Mb/s fibre G-links and a third battery-powered system using a slower link. We describe the power and slow control systems of the underwater hub.

  14. In Brief: Deep-sea observatory gets undersea cable

    NASA Astrophysics Data System (ADS)

    Zielinski, Sarah

    2007-04-01

    More than 50 kilometers of cable have been buried about a meter beneath the seafloor of Monterey Bay, Calif., to provide power and carry data for the first U.S. deep-sea cabled observatory. When finished later this year, the Monterey Accelerated Research System (MARS) observatory will provide scientists with constant access to any instrumentation, such as seismographs or oceanographic monitoring stations, plugged into its science node. Later this fall, a trawl-resistant frame will be installed at the end of the cable and provide a home for a computer network hub and electrical substation to which instrumentation can be attached. MARS will support oceanographic research within Monterey Bay and provide a testing ground for technology that can be used in future deep-sea observatories. MARS (http://www.mbari.org/mars/) is a multiinstitutional effort led by the Monterey Bay Aquarium Research Institute and funded by the U.S. National Science Foundation.

  15. Alchemy or Science? Compromising Archaeology in the Deep Sea

    NASA Astrophysics Data System (ADS)

    Adams, Jonathan

    2007-06-01

    In the torrid debate between archaeology and treasure hunting, compromise is often suggested as the pragmatic solution, especially for archaeology carried out either in deep water or beyond the constraints that commonly regulate such activities in territorial seas. Both the wisdom and the need for such compromise have even been advocated by some archaeologists, particularly in forums such as the internet and conferences. This paper argues that such a compromise is impossible, not in order to fuel confrontation but simply because of the nature of any academic discipline. We can define what archaeology is in terms of its aims, theories, methods and ethics, so combining it with an activity founded on opposing principles must transform it into something else. The way forward for archaeology in the deep sea does not lie in a contradictory realignment of archaeology’s goals but in collaborative research designed to mesh with emerging national and regional research and management plans.

  16. Antarctic Marine Biodiversity and Deep-Sea Hydrothermal Vents

    PubMed Central

    Chown, Steven L.

    2012-01-01

    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 hydrothermal vents. Vent ecosystems have been documented from many sites 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 vent ecosystems are very different to those elsewhere, though the microbiota, which form the basis of vent food webs, show less differentiation. Much of the biological significance of deep-sea hydrothermal vents 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 hydrothermal vent ecosystems provides opportunities for new understanding in these fields. Moreover, the Antarctic vents 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 hydrothermal vents located in international waters are not protected and may be threatened by growing interests in deep-sea mining. PMID:22235192

  17. Ecosystem function and services provided by the deep sea

    NASA Astrophysics Data System (ADS)

    Thurber, A. R.; Sweetman, A. K.; Narayanaswamy, B. E.; Jones, D. O. B.; Ingels, J.; Hansman, R. L.

    2013-11-01

    The deep sea is often viewed as a vast, dark, remote, and inhospitable environment, yet the deep ocean and seafloor are crucial to our lives through the services and provisions that they provide. Our understanding of how the deep sea functions remains limited, but when treated synoptically, a diversity of provisioning, regulating and cultural services become apparent. The biological pump transports carbon from the atmosphere into deep-ocean water masses which are separated over prolonged periods, reducing the impact of anthropogenic carbon release. Microbial oxidation of methane keeps another potent greenhouse gas out of the atmosphere while trapping carbon in authigenic carbonates. Nutrient regeneration by all faunal size classes provides the elements necessary to fuel surface productivity and fisheries, and microbial processes detoxify a diversity of compounds. Each of these processes occur on a very small scale, yet considering the vast area over which they occur they become important for the global functioning of the ocean. The deep sea also provides a diversity of resources, including fish stocks, enormous bioprospecting potential, and elements and energy reserves that are currently being extracted and will be increasingly important in the near future. Society benefits from the intrigue and mystery, the strange life forms, and the great unknown which has acted as a muse for inspiration and imagination since near the beginning of civilization. While many functions occur on the scale of microns to meters and time scales up to years, the derived services that result are only useful after centuries of integrated activity. This vast dark habitat, that covers the majority of the globe, harbors processes that directly impact humans in a diversity of ways, however the same traits that differentiate it from terrestrial or shallow marine systems also result in a greater need for integrated spatial and temporal understanding as it experiences increased use by society.

  18. Russian deep-sea investigations of Antarctic fauna

    NASA Astrophysics Data System (ADS)

    Malyutina, Marina

    2004-07-01

    A review of the Russian deep-sea investigation of Antarctic fauna beginning from the first scientific collection of Soviet whaling fleet expeditions 1946-1952 is presented. The paper deals with the following expeditions, their main tasks and results. These expeditions include three cruises of research vessel (R.V.) Ob in the Indian sector of the Antarctic and in the Southern Pacific (1955-1958); 11 cruises of the R.V. Akademik Kurchatov in the southern Atlantic (November-December 1971); 16 cruises of the R.V. Dmitriy Mendeleev in the Australia-New Zealand area and adjacent water of the Antarctic (December 1975-March 1976); 43 cruises of the R.V. Akademik Kurchatov in the southern Atlantic (October 1985-February 1986); and 43 cruises of the R.V. Dmitriy Mendeleev in the Atlantic sector of the South Ocean (January-May 1989). A list of the main publications on the benthic taxa collected during these expeditions with data of their distribution is presented. The results of Russian explorations of the Antarctic fauna are presented as theoretical conclusions in the following topics: (1) Vertical zonation in the distribution of the Antarctic deep-sea fauna; (2) Biogeographic division of the abyssal and hadal zones; (3) Origin of the Antarctic deep-sea fauna; (4) Distributional pathways of the Antarctic abyssal fauna through the World Ocean.

  19. Deep-sea smokers: windows to a subsurface biosphere?

    PubMed

    Deming, J W; Baross, J A

    1993-07-01

    Since the discovery of hyperthermophilic microbial activity in hydrothermal fluids recovered from "smoker" vents on the East Pacific Rise, the widely accepted upper temperature limit for life (based on pure culture data) has risen from below the boiling point of water at atmospheric pressure to approximately 115 degrees C. Many microbiologists seem willing to speculate that the maximum may be closer to 150 degrees C. We have postulated not only higher temperatures than these (under deep-sea hydrostatic pressures), but also the existence of a biosphere subsurface to accessible seafloor vents. New geochemical information from the Endeavour Segment of the Juan de Fuca Ridge indicative of subsurface organic material caused us to re-examine both the literature on hyperthermophilic microorganisms cultured from deep-sea smoker environments and recent results of microbial sampling efforts at actively discharging smokers on the Endeavour Segment. Here we offer the case for a subsurface biosphere based on an interdisciplinary view of microbial and geochemical analyses of Endeavour smoker fluids, a case in keeping with rapidly evolving geophysical understanding of organic stability under deep-sea hydrothermal conditions.

  20. Late Eocene impact events recorded in deep-sea sediments

    NASA Technical Reports Server (NTRS)

    Glass, B. P.

    1988-01-01

    Raup and Sepkoski proposed that mass extinctions have occurred every 26 Myr during the last 250 Myr. In order to explain this 26 Myr periodicity, it was proposed that the mass extinctions were caused by periodic increases in cometary impacts. One method to test this hypothesis is to determine if there were periodic increases in impact events (based on crater ages) that correlate with mass extinctions. A way to test the hypothesis that mass extinctions were caused by periodic increases in impact cratering is to look for evidence of impact events in deep-sea deposits. This method allows direct observation of the temporal relationship between impact events and extinctions as recorded in the sedimentary record. There is evidence in the deep-sea record for two (possibly three) impact events in the late Eocene. The younger event, represented by the North American microtektite layer, is not associated with an Ir anomaly. The older event, defined by the cpx spherule layer, is associated with an Ir anomaly. However, neither of the two impact events recorded in late Eocene deposits appears to be associated with an unusual number of extinctions. Thus there is little evidence in the deep-sea record for an impact-related mass extinction in the late Eocene.

  1. How Deep-Sea Wood Falls Sustain Chemosynthetic Life

    PubMed Central

    Bienhold, Christina; Pop Ristova, Petra; Wenzhöfer, Frank; Dittmar, Thorsten; Boetius, Antje

    2013-01-01

    Large organic food falls to the deep sea – such as whale carcasses and wood logs – are known to serve as stepping stones for the dispersal of highly adapted chemosynthetic organisms inhabiting hot vents and cold seeps. Here we investigated the biogeochemical and microbiological processes leading to the development of sulfidic niches by deploying wood colonization experiments at a depth of 1690 m in the Eastern Mediterranean for one year. Wood-boring bivalves of the genus Xylophaga played a key role in the degradation of the wood logs, facilitating the development of anoxic zones and anaerobic microbial processes such as sulfate reduction. Fauna and bacteria associated with the wood included types reported from other deep-sea habitats including chemosynthetic ecosystems, confirming the potential role of large organic food falls as biodiversity hot spots and stepping stones for vent and seep communities. Specific bacterial communities developed on and around the wood falls within one year and were distinct from freshly submerged wood and background sediments. These included sulfate-reducing and cellulolytic bacterial taxa, which are likely to play an important role in the utilization of wood by chemosynthetic life and other deep-sea animals. PMID:23301092

  2. Rhone deep-sea fan: morphostructure and growth pattern

    SciTech Connect

    Droz, L.; Bellaiche, G.

    1985-03-01

    A detailed bathymetric survey of the Rhone deep-sea fan and its feeder canyon using Sea-Beam, reveals morphologic features such as very tight meanders of the canyon and channel courses, cutoff meanders, and downslope narrowing of the inner channel floor. Striking similarities exist between these deep-sea features and some continental landforms, especially in alluvial plain areas or desert environments. Sea-Beam also reveals evidence of huge slump scars affecting the slope and fan. The superficial structure of the Rhone Fan results from the stacking of numerous lenticular acoustic units displaying specific seismic characters in which the authors recognized channel and levee facies. Except in the upper fan area, these units have not been constant; they have generally migrated, owing to shifting of the channel throughout fan evolution. Construction of the fan probably began as early as the early Pliocene and continued to the close of the Wurmian (late Wisconsinian). The fan's growth pattern could be associated with climatic fluctuations. The principal sedimentary mechanism responsible for the growth of the fan appears to be turbidity currents, but mass gravity flows have also been an important factor in building the fan by occasionally blocking the main channel and forcing it to migrate.

  3. Evolution of recombination rates in a multi-locus, haploid-selection, symmetric-viability model.

    PubMed

    Chasnov, J R; Ye, Felix Xiaofeng

    2013-02-01

    A fast algorithm for computing multi-locus recombination is extended to include a recombination-modifier locus. This algorithm and a linear stability analysis is used to investigate the evolution of recombination rates in a multi-locus, haploid-selection, symmetric-viability model for which stable equilibria have recently been determined. When the starting equilibrium is symmetric with two selected loci, we show analytically that modifier alleles that reduce recombination always invade. When the starting equilibrium is monomorphic, and there is a fixed nonzero recombination rate between the modifier locus and the selected loci, we determine analytical conditions for which a modifier allele can invade. In particular, we show that a gap exists between the recombination rates of modifiers that can invade and the recombination rate that specifies the lower stability boundary of the monomorphic equilibrium. A numerical investigation shows that a similar gap exists in a weakened form when the starting equilibrium is fully polymorphic but asymmetric.

  4. Deep-sea pennatulaceans (sea pens) - recent discoveries, morphological adaptations, and responses to benthic oceanographic parameters

    NASA Astrophysics Data System (ADS)

    Williams, G. C.

    2015-12-01

    Pennatulaceans are sessile, benthic marine organisms that are bathymetrically wide-ranging, from the intertidal to approximately 6300 m in depth, and are conspicuous constituents of deep-sea environments. The vast majority of species are adapted for anchoring in soft sediments by the cylindrical peduncle - a muscular hydrostatic skeleton. However, in the past decade a few species ("Rockpens") have been discovered and described that can attach to hard substratum such as exposed rocky outcrops at depths between 669 and 1969 m, by a plunger-like adaptation of the base of the peduncle. Of the thirty-six known genera, eleven (or 30%) have been recorded from depths greater than 1000 m. The pennatulacean depth record holders are an unidentified species of Umbellula from 6260 m in the Peru-Chile Trench and a recently-discovered and described genus and species, Porcupinella profunda, from 5300 m the Porcupine Abyssal Plain of the northeastern Atlantic. A morphologically-differentiated type of polyp (acrozooid) have recently been discovered and described in two genera of shallow-water coral reef sea pens. Acrozooids apparently represent asexual buds and presumably can detach from the adult to start clonal colonies through asexual budding. Acrozooids are to be expected in deep-sea pennatulaceans, but so far have not been observed below 24 m in depth. Morphological responses at depths greater than 1000 m in deep-sea pennatulaceas include: fewer polyps, larger polyps, elongated stalks, and clustering of polyps along the rachis. Responses to deep-ocean physical parameters and anthropogenic changes that could affect the abundance and distribution of deep-sea pennatulaceans include changes in bottom current flow and food availability, changes in seawater temperature and pH, habitat destruction by fish trawling, and sunken refuse pollution. No evidence of the effects of ocean acidification or other effects of anthropogenic climate change in sea pens of the deep-sea has been

  5. Consensus multi-locus sequence typing scheme for Cryptococcus neoformans and Cryptococcus gattii

    PubMed Central

    Meyer, Wieland; Aanensen, David M.; Boekhout, Teun; Cogliati, Massimo; Diaz, Mara R.; Esposto, Maria Carmela; Fisher, Matthew; Gilgado, Felix; Hagen, Ferry; Kaocharoen, Sirada; Litvintseva, Anastasia P.; Mitchell, Thomas G.; Simwami, Sitali P.; Trilles, Luciana; Viviani, Maria Anna; Kwon-Chung, June

    2010-01-01

    This communication describes the consensus multi-locus typing scheme established by the Cryptococcal Working Group I (Genotyping of Cryptococcus neoformans and C. gattii) of the International Society for Human and Animal Mycology (ISHAM) using seven unlinked genetic loci for global strain genotyping. These genetic loci include the housekeeping genes CAP59, GPD1, LAC1, PLB1, SOD1, URA5 and the IGS1 region. Allele and sequence type information are accessible at http://www.mlst.net/. PMID:19462334

  6. First glimpse into Lower Jurassic deep-sea biodiversity: in situ diversification and resilience against extinction.

    PubMed

    Thuy, Ben; Kiel, Steffen; Dulai, Alfréd; Gale, Andy S; Kroh, Andreas; Lord, Alan R; Numberger-Thuy, Lea D; Stöhr, Sabine; Wisshak, Max

    2014-07-07

    Owing to the assumed lack of deep-sea macrofossils older than the Late Cretaceous, very little is known about the geological history of deep-sea communities, and most inference-based hypotheses argue for repeated recolonizations of the deep sea from shelf habitats following major palaeoceanographic perturbations. We present a fossil deep-sea assemblage of echinoderms, gastropods, brachiopods and ostracods, from the Early Jurassic of the Glasenbach Gorge, Austria, which includes the oldest known representatives of a number of extant deep-sea groups, and thus implies that in situ diversification, in contrast to immigration from shelf habitats, played a much greater role in shaping modern deep-sea biodiversity than previously thought. A comparison with coeval shelf assemblages reveals that, at least in some of the analysed groups, significantly more extant families/superfamilies have endured in the deep sea since the Early Jurassic than in the shelf seas, which suggests that deep-sea biota are more resilient against extinction than shallow-water ones. In addition, a number of extant deep-sea families/superfamilies found in the Glasenbach assemblage lack post-Jurassic shelf occurrences, implying that if there was a complete extinction of the deep-sea fauna followed by replacement from the shelf, it must have happened before the Late Jurassic.

  7. Seqestration of dissolved organic carbon in the deep sea

    SciTech Connect

    Daniel J. Repeta

    2006-03-01

    There are 600 GT of dissolved organic carbon (DOC) sequestered in seawater. The marine inventory of DOC is set by its concentration in the deep sea, which is nearly constant at 35+2µM C, irrespective of sample location or depth. Isotopic measurements show deep sea DOC to be depleted in radiocarbon, with an apparent radiocarbon age of between 4000ybp (Atlantic) and 6000ybp (Pacific). From the radiocarbon data, we can infer that deep sea DOC is inert and does not cycle on less than millennial time scales. However, high precision DOC measurements show deep sea concentrations are variable at the + 1-2µM DOC level, suggesting a fraction of deep sea DOC, equivalent to 15-30Gt C, is cycling on short time scales, acting as a sink for new, atmospheric carbon. This project is designed to identify and quantify the biological and physical processes that sequester DOM in the deep sea by making compound specific radiocarbon measurements on sugars and proteins extracted from deep sea DOC. Our Hawaii surface seawater sample has a DIC Δ14C value of 72 + 7 ‰ and shows the influence of bomb radiocarbon on surface water DIC values. HMWDOC Δ14C is 10 ‰, significantly depleted in radiocarbon relative to DIC. Purification of HMWDOC by reverse phase HPLC yields seven neutral sugars with radiocarbon values of 47 – 67‰. Assuming the radiocarbon determinations of individual sugars in HMWDOC serve as replicates, then the average Δ14C for neutral sugars in HMWDOC is 57 + 6 ‰(1 SD, n=11), only slightly depleted in 14C relative to DIC. There has been a sharp decrease in radiocarbon values for DIC in the North Pacific Ocean over the past few decades. If neutral sugars cycle more slowly than DIC, we would expect them to have correspondingly higher radiocarbon values. Previous studies have modeled upper ocean DOC as a two component mixture of newly synthesized DOC with a radiocarbon value equal to DIC, and an old component with a radiocarbon value equal to deep sea DO14C. In order to

  8. Sea-level and deep-sea-temperature variability over the past 5.3 million years.

    PubMed

    Rohling, E J; Foster, G L; Grant, K M; Marino, G; Roberts, A P; Tamisiea, M E; Williams, F

    2014-04-24

    Ice volume (and hence sea level) and deep-sea temperature are key measures of global climate change. Sea level has been documented using several independent methods over the past 0.5 million years (Myr). Older periods, however, lack such independent validation; all existing records are related to deep-sea oxygen isotope (δ(18)O) data that are influenced by processes unrelated to sea level. For deep-sea temperature, only one continuous high-resolution (Mg/Ca-based) record exists, with related sea-level estimates, spanning the past 1.5 Myr. Here we present a novel sea-level reconstruction, with associated estimates of deep-sea temperature, which independently validates the previous 0-1.5 Myr reconstruction and extends it back to 5.3 Myr ago. We find that deep-sea temperature and sea level generally decreased through time, but distinctly out of synchrony, which is remarkable given the importance of ice-albedo feedbacks on the radiative forcing of climate. In particular, we observe a large temporal offset during the onset of Plio-Pleistocene ice ages, between a marked cooling step at 2.73 Myr ago and the first major glaciation at 2.15 Myr ago. Last, we tentatively infer that ice sheets may have grown largest during glacials with more modest reductions in deep-sea temperature.

  9. Reduced enzymatic antioxidative defense in deep-sea fish.

    PubMed

    Janssens, B J; Childress, J J; Baguet, F; Rees, J F

    2000-12-01

    Oxygen, while being an obligate fuel for aerobic life, has been shown to be toxic through its deleterious reactive species, which can cause oxidative stress and lead ultimately to cell and organism death. In marine organisms, reactive oxygen species (ROS), such as the superoxide anion and hydrogen peroxide, are generated within respiring cells and tissues and also by photochemical processes in sea water. Considering both the reduced metabolic rate of nektonic organisms thriving in the deep sea and the physico-chemical conditions of this dark, poorly oxygenated environment, the meso- and bathypelagic waters of the oceans might be considered as refuges against oxidative dangers. This hypothesis prompted us to investigate the activities of the three essential enzymes (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase, GPX) constitutive of the antioxidative arsenal of cells in the tissues of 16 species of meso- and bathypelagic fishes occurring between the surface and a depth of 1300 m. While enzymatic activities were detected in all tissues from all species, the levels of SOD and GPX decreased in parallel with the exponential reduction in the metabolic activity as estimated by citrate synthase activity. In contrast, CAT was affected neither by the metabolic activity nor by the depth of occurrence of the fishes. High levels of metabolic and antioxidative enzymes were detected in the light organs of bioluminescent species. The adjustment of the activity of SOD and GPX to the decreased metabolic activity associated with deep-sea living suggests that these antioxidative defense mechanisms are used primarily against metabolically produced ROS, whereas the maintenance of CAT activity throughout all depths could be indicative of another role. The possible reasons for the occurrence of such a reduced antioxidative arsenal in deep-sea species are discussed.

  10. Identification of new deep sea sinuous channels in the eastern Arabian Sea.

    PubMed

    Mishra, Ravi; Pandey, D K; Ramesh, Prerna; Clift, Peter D

    2016-01-01

    Deep sea channel systems are recognized in most submarine fans worldwide as well as in the geological record. The Indus Fan is the second largest modern submarine fan, having a well-developed active canyon and deep sea channel system. Previous studies from the upper Indus Fan have reported several active channel systems. In the present study, deep sea channel systems were identified within the middle Indus Fan using high resolution multibeam bathymetric data. Prominent morphological features within the survey block include the Raman Seamount and Laxmi Ridge. The origin of the newly discovered channels in the middle fan has been inferred using medium resolution satellite bathymetry data. Interpretation of new data shows that the highly sinuous deep sea channel systems also extend to the east of Laxmi Ridge, as well as to the west of Laxmi Ridge, as previously reported. A decrease in sinuosity southward can be attributed to the morphological constraints imposed by the elevated features. These findings have significance in determining the pathways for active sediment transport systems, as well as their source characterization. The geometry suggests a series of punctuated avulsion events leading to the present array of disconnected channels. Such channels have affected the Laxmi Basin since the Pliocene and are responsible for reworking older fan sediments, resulting in loss of the original erosional signature supplied from the river mouth. This implies that distal fan sediments have experienced significant signal shredding and may not represent the erosion and weathering conditions within the onshore basin at the time of sedimentation.

  11. Sea-surface and deep-magnetic data at Vavilov Seamount, Tyrrhenian Sea

    NASA Astrophysics Data System (ADS)

    Muccini, Filippo; Cocchi, Luca; Locritani, Marina; Carmisciano, Cosmo

    2016-04-01

    Sea surface and deep magnetic data were acquired at Vavilov seamount, in the Tyrrhenian sea. Vavilov seamount is located in the central portion of the homonymous Vavilov basin. The seamount stands about 2800 meters above the seafloor at 3600 meters depth, with the top at about 800 meters below the sea level. Oceanization of the basin occurred during the Late Miocene-Early Pliocene. The magnetic data were collected in 2011 on board the Nave Ammiraglio Magnaghi by using a Marine Magnetics Seaspy magnetometer. The sea surface magnetic survey was realized with two different grids: the first regional one, with 13 parallel lines about 43 Km long, 3 Km spaced (104° N oriented) and 6 tie control lines about 40 Km long, 5 Km spaced (014° N oriented). The second one was realized to better define the volcanic structure of the seamount, and was achieved by acquiring 12 magnetic parallel lines (104° N), 18 Km long and 1 Km spaced. The deep magnetic data were collected by towing a magnetic sensor coupled with a L3 sidescan sonar Klein 3000. A set of 5 parallel lines were acquired in correspondence of the bathymetric top of the seamount with the sensor flying at about constant depth of 700 meters. These data represents the first near-bottom magnetic data collected for Vavilov seamount and it allows comparison between sea-surface and deep magnetic data.

  12. Antifouling potentials of eight deep-sea-derived fungi from the South China Sea.

    PubMed

    Zhang, Xiao-Yong; Xu, Xin-Ya; Peng, Jiang; Ma, Chun-Feng; Nong, Xu-Hua; Bao, Jie; Zhang, Guang-Zhao; Qi, Shu-Hua

    2014-04-01

    Marine-derived microbial secondary metabolites are promising potential sources of nontoxic antifouling agents. The search for environmentally friendly and low-toxic antifouling components guided us to investigate the antifouling potentials of eight novel fungal isolates from deep-sea sediments of the South China Sea. Sixteen crude ethyl acetate extracts of the eight fungal isolates showed distinct antibacterial activity against three marine bacteria (Loktanella hongkongensis UST950701-009, Micrococcus luteus UST950701-006 and Pseudoalteromonas piscida UST010620-005), or significant antilarval activity against larval settlement of bryozoan Bugula neritina. Furthermore, the extract of Aspergillus westerdijkiae DFFSCS013 displayed strong antifouling activity in a field trial lasting 4 months. By further bioassay-guided isolation, five antifouling alkaloids including brevianamide F, circumdatin F and L, notoamide C, and 5-chlorosclerotiamide were isolated from the extract of A. westerdijkiae DFFSCS013. This is the first report about the antifouling potentials of metabolites of the deep-sea-derived fungi from the South China Sea, and the first stage towards the development of non- or low-toxic antifouling agents from deep-sea-derived fungi.

  13. Exploitation of deep-sea resources: the urgent need to understand the role of high pressure in the toxicity of chemical pollutants to deep-sea organisms.

    PubMed

    Mestre, Nélia C; Calado, Ricardo; Soares, Amadeu M V M

    2014-02-01

    The advent of industrial activities in the deep sea will inevitably expose deep-sea organisms to potentially toxic compounds. Although international regulations require environmental risk assessment prior to exploitation activities, toxicity tests remain focused on shallow-water model species. Moreover, current tests overlook potential synergies that may arise from the interaction of chemicals with natural stressors, such as the high pressures prevailing in the deep sea. As pressure affects chemical reactions and the physiology of marine organisms, it will certainly affect the toxicity of pollutants arising from the exploitation of deep-sea resources. We emphasize the need for environmental risk assessments based on information generated from ecotoxicological trials that mimic, as close as possible, the deep-sea environment, with emphasis to a key environmental factor - high hydrostatic pressure.

  14. Global diversity and biogeography of deep-sea pelagic prokaryotes.

    PubMed

    Salazar, Guillem; Cornejo-Castillo, Francisco M; Benítez-Barrios, Verónica; Fraile-Nuez, Eugenio; Álvarez-Salgado, X Antón; Duarte, Carlos M; Gasol, Josep M; Acinas, Silvia G

    2016-03-01

    The deep-sea is the largest biome of the biosphere, and contains more than half of the whole ocean's microbes. Uncovering their general patterns of diversity and community structure at a global scale remains a great challenge, as only fragmentary information of deep-sea microbial diversity exists based on regional-scale studies. Here we report the first globally comprehensive survey of the prokaryotic communities inhabiting the bathypelagic ocean using high-throughput sequencing of the 16S rRNA gene. This work identifies the dominant prokaryotes in the pelagic deep ocean and reveals that 50% of the operational taxonomic units (OTUs) belong to previously unknown prokaryotic taxa, most of which are rare and appear in just a few samples. We show that whereas the local richness of communities is comparable to that observed in previous regional studies, the global pool of prokaryotic taxa detected is modest (~3600 OTUs), as a high proportion of OTUs are shared among samples. The water masses appear to act as clear drivers of the geographical distribution of both particle-attached and free-living prokaryotes. In addition, we show that the deep-oceanic basins in which the bathypelagic realm is divided contain different particle-attached (but not free-living) microbial communities. The combination of the aging of the water masses and a lack of complete dispersal are identified as the main drivers for this biogeographical pattern. All together, we identify the potential of the deep ocean as a reservoir of still unknown biological diversity with a higher degree of spatial complexity than hitherto considered.

  15. Global diversity and biogeography of deep-sea pelagic prokaryotes

    PubMed Central

    Salazar, Guillem; Cornejo-Castillo, Francisco M; Benítez-Barrios, Verónica; Fraile-Nuez, Eugenio; Álvarez-Salgado, X Antón; Duarte, Carlos M; Gasol, Josep M; Acinas, Silvia G

    2016-01-01

    The deep-sea is the largest biome of the biosphere, and contains more than half of the whole ocean's microbes. Uncovering their general patterns of diversity and community structure at a global scale remains a great challenge, as only fragmentary information of deep-sea microbial diversity exists based on regional-scale studies. Here we report the first globally comprehensive survey of the prokaryotic communities inhabiting the bathypelagic ocean using high-throughput sequencing of the 16S rRNA gene. This work identifies the dominant prokaryotes in the pelagic deep ocean and reveals that 50% of the operational taxonomic units (OTUs) belong to previously unknown prokaryotic taxa, most of which are rare and appear in just a few samples. We show that whereas the local richness of communities is comparable to that observed in previous regional studies, the global pool of prokaryotic taxa detected is modest (~3600 OTUs), as a high proportion of OTUs are shared among samples. The water masses appear to act as clear drivers of the geographical distribution of both particle-attached and free-living prokaryotes. In addition, we show that the deep-oceanic basins in which the bathypelagic realm is divided contain different particle-attached (but not free-living) microbial communities. The combination of the aging of the water masses and a lack of complete dispersal are identified as the main drivers for this biogeographical pattern. All together, we identify the potential of the deep ocean as a reservoir of still unknown biological diversity with a higher degree of spatial complexity than hitherto considered. PMID:26251871

  16. Distribution and assessment of marine debris in the deep Tyrrhenian Sea (NW Mediterranean Sea, Italy).

    PubMed

    Angiolillo, Michela; di Lorenzo, Bianca; Farcomeni, Alessio; Bo, Marzia; Bavestrello, Giorgio; Santangelo, Giovanni; Cau, Angelo; Mastascusa, Vincenza; Cau, Alessandro; Sacco, Flavio; Canese, Simonepietro

    2015-03-15

    Marine debris is a recognized global ecological concern. Little is known about the extent of the problem in the Mediterranean Sea regarding litter distribution and its influence on deep rocky habitats. A quantitative assessment of debris present in the deep seafloor (30-300 m depth) was carried out in 26 areas off the coast of three Italian regions in the Tyrrhenian Sea, using a Remotely Operated Vehicle (ROV). The dominant type of debris (89%) was represented by fishing gears, mainly lines, while plastic objects were recorded only occasionally. Abundant quantities of gears were found on rocky banks in Sicily and Campania (0.09-0.12 debris m(-2)), proving intense fishing activity. Fifty-four percent of the recorded debris directly impacted benthic organisms, primarily gorgonians, followed by black corals and sponges. This work provides a first insight on the impact of marine debris in Mediterranean deep ecosystems and a valuable baseline for future comparisons.

  17. Deep sea mega-geomorphology: Progress and problems

    NASA Technical Reports Server (NTRS)

    Bryan, W. B.

    1985-01-01

    Historically, marine geologists have always worked with mega-scale morphology. This is a consequence both of the scale of the ocean basins and of the low resolution of the observational remote sensing tools available until very recently. In fact, studies of deep sea morphology have suffered from a serious gap in observational scale. Traditional wide-beam echo sounding gave images on a scale of miles, while deep sea photography has been limited to scales of a few tens of meters. Recent development of modern narrow-beam echo sounding coupled with computer-controlled swath mapping systems, and development of high-resolution deep-towed side-scan sonar, are rapidly filling in the scale gap. These technologies also can resolve morphologic detail on a scale of a few meters or less. As has also been true in planetary imaging projects, the ability to observe phenomena over a range of scales has proved very effective in both defining processes and in placing them in proper context.

  18. Age, growth rates, and paleoclimate studies of deep sea corals

    USGS Publications Warehouse

    Prouty, Nancy G; Roark, E. Brendan; Andrews, Allen; Robinson, Laura; Hill, Tessa; Sherwood, Owen; Williams, Branwen; Guilderson, Thomas P.; Fallon, Stewart

    2015-01-01

    Deep-water corals are some of the slowest growing, longest-lived skeletal accreting marine organisms. These habitat-forming species support diverse faunal assemblages that include commercially and ecologically important organisms. Therefore, effective management and conservation strategies for deep-sea corals can be informed by precise and accurate age, growth rate, and lifespan characteristics for proper assessment of vulnerability and recovery from perturbations. This is especially true for the small number of commercially valuable, and potentially endangered, species that are part of the black and precious coral fisheries (Tsounis et al. 2010). In addition to evaluating time scales of recovery from disturbance or exploitation, accurate age and growth estimates are essential for understanding the life history and ecology of these habitat-forming corals. Given that longevity is a key factor for population maintenance and fishery sustainability, partly due to limited and complex genetic flow among coral populations separated by great distances, accurate age structure for these deep-sea coral communities is essential for proper, long-term resource management.

  19. Characterization of plutonium in deep-sea sediments of the Sulu and South China Seas.

    PubMed

    Dong, Wei; Zheng, Jian; Guo, Qiuju; Yamada, Masatoshi; Pan, Shaoming

    2010-08-01

    Anthropogenic Pu isotopes are important geochemical tracers for sediment studies. Their distributions and sources in the water columns as well as the sediments of the North Pacific have been intensively studied; however, information about Pu in the Southeast Asian seas is limited. To study the isotopic composition of Pu, and thus to identify its sources, we collected sediment core samples in the South China Sea and the Sulu Sea during the KH-96-5 Cruise of the R/V Hakuho Maru. We analysed the activities of (239+240)Pu and the atom ratios of (240)Pu/(239)Pu using isotope dilution sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS). The (240)Pu/(239)Pu atom ratios in the sediments of both areas (inventory weighted mean: 0.251 for the South China Sea and 0.280 for the Sulu Sea) were higher than the global fallout value (0.178+/-0.019), suggesting the existence of Pu from the Pacific Proving Grounds in the North Pacific. Low inventories of (239+240)Pu in sediments were observed in the South China Sea (3.75 Bq/m(2)) and the Sulu Sea (1.38 Bq/m(2)). Most of the Pu input is still present in the water column. Scavenging and benthic mixing processes were considered to be the main processes controlling the distribution of Pu in the deep-sea sediments of both study areas.

  20. Deep-sea benthic footprint of the deepwater horizon blowout.

    PubMed

    Montagna, Paul A; Baguley, Jeffrey G; Cooksey, Cynthia; Hartwell, Ian; Hyde, Larry J; Hyland, Jeffrey L; Kalke, Richard D; Kracker, Laura M; Reuscher, Michael; Rhodes, Adelaide C E

    2013-01-01

    The Deepwater Horizon (DWH) accident in the northern Gulf of Mexico occurred on April 20, 2010 at a water depth of 1525 meters, and a deep-sea plume was detected within one month. Oil contacted and persisted in parts of the bottom of the deep-sea in the Gulf of Mexico. As part of the response to the accident, monitoring cruises were deployed in fall 2010 to measure potential impacts on the two main soft-bottom benthic invertebrate groups: macrofauna and meiofauna. Sediment was collected using a multicorer so that samples for chemical, physical and biological analyses could be taken simultaneously and analyzed using multivariate methods. The footprint of the oil spill was identified by creating a new variable with principal components analysis where the first factor was indicative of the oil spill impacts and this new variable mapped in a geographic information system to identify the area of the oil spill footprint. The most severe relative reduction of faunal abundance and diversity extended to 3 km from the wellhead in all directions covering an area about 24 km(2). Moderate impacts were observed up to 17 km towards the southwest and 8.5 km towards the northeast of the wellhead, covering an area 148 km(2). Benthic effects were correlated to total petroleum hydrocarbon, polycyclic aromatic hydrocarbons and barium concentrations, and distance to the wellhead; but not distance to hydrocarbon seeps. Thus, benthic effects are more likely due to the oil spill, and not natural hydrocarbon seepage. Recovery rates in the deep sea are likely to be slow, on the order of decades or longer.

  1. Radiocarbon Based Ages and Growth Rates: Hawaiian Deep Sea Corals

    SciTech Connect

    Roark, E B; Guilderson, T P; Dunbar, R B; Ingram, B L

    2006-01-13

    The radial growth rates and ages of three different groups of Hawaiian deep-sea 'corals' were determined using radiocarbon measurements. Specimens of Corallium secundum, Gerardia sp., and Leiopathes glaberrima, were collected from 450 {+-} 40 m at the Makapuu deep-sea coral bed using a submersible (PISCES V). Specimens of Antipathes dichotoma were collected at 50 m off Lahaina, Maui. The primary source of carbon to the calcitic C. secundum skeleton is in situ dissolved inorganic carbon (DIC). Using bomb {sup 14}C time markers we calculate radial growth rates of {approx} 170 {micro}m y{sup -1} and ages of 68-75 years on specimens as tall as 28 cm of C. secundum. Gerardia sp., A. dichotoma, and L. glaberrima have proteinaceous skeletons and labile particulate organic carbon (POC) is their primary source of architectural carbon. Using {sup 14}C we calculate a radial growth rate of 15 {micro}m y{sup -1} and an age of 807 {+-} 30 years for a live collected Gerardia sp., showing that these organisms are extremely long lived. Inner and outer {sup 14}C measurements on four sub-fossil Gerardia spp. samples produce similar growth rate estimates (range 14-45 {micro}m y{sup -1}) and ages (range 450-2742 years) as observed for the live collected sample. Similarly, with a growth rate of < 10 {micro}m y{sup -1} and an age of {approx}2377 years, L. glaberrima at the Makapuu coral bed, is also extremely long lived. In contrast, the shallow-collected A. dichotoma samples yield growth rates ranging from 130 to 1,140 {micro}m y{sup -1}. These results show that Hawaiian deep-sea corals grow more slowly and are older than previously thought.

  2. Deep-Sea Benthic Footprint of the Deepwater Horizon Blowout

    PubMed Central

    Montagna, Paul A.; Baguley, Jeffrey G.; Cooksey, Cynthia; Hartwell, Ian; Hyde, Larry J.; Hyland, Jeffrey L.; Kalke, Richard D.; Kracker, Laura M.; Reuscher, Michael; Rhodes, Adelaide C. E.

    2013-01-01

    The Deepwater Horizon (DWH) accident in the northern Gulf of Mexico occurred on April 20, 2010 at a water depth of 1525 meters, and a deep-sea plume was detected within one month. Oil contacted and persisted in parts of the bottom of the deep-sea in the Gulf of Mexico. As part of the response to the accident, monitoring cruises were deployed in fall 2010 to measure potential impacts on the two main soft-bottom benthic invertebrate groups: macrofauna and meiofauna. Sediment was collected using a multicorer so that samples for chemical, physical and biological analyses could be taken simultaneously and analyzed using multivariate methods. The footprint of the oil spill was identified by creating a new variable with principal components analysis where the first factor was indicative of the oil spill impacts and this new variable mapped in a geographic information system to identify the area of the oil spill footprint. The most severe relative reduction of faunal abundance and diversity extended to 3 km from the wellhead in all directions covering an area about 24 km2. Moderate impacts were observed up to 17 km towards the southwest and 8.5 km towards the northeast of the wellhead, covering an area 148 km2. Benthic effects were correlated to total petroleum hydrocarbon, polycyclic aromatic hydrocarbons and barium concentrations, and distance to the wellhead; but not distance to hydrocarbon seeps. Thus, benthic effects are more likely due to the oil spill, and not natural hydrocarbon seepage. Recovery rates in the deep sea are likely to be slow, on the order of decades or longer. PMID:23950956

  3. Power, fresh water, and food from cold, deep sea water.

    PubMed

    Othmer, D F; Roels, O A

    1973-10-12

    Many times more solar heat energy accumulates in the vast volume of warm tropic seas than that produced by all of our power plants. The looming energy crisis causes a renewal of interest in utilizing this stored solar heat to give, in addition to electric power, vast quantities of fresh water. Warm surface water, when evaporated, generates steam, to power a turbine, then fresh water when the steam is condensed by the cold water. A great increase in revenues over that from power and fresh water is shown by a substantial mariculture pilot plant. Deep sea water contains large quantities of nutrients. These feed algae which feed shellfish, ultimately shrimps and lobsters, in shallow ponds. Wastes grow seaweed of value; and combined revenues from desalination, power generation, and mariculture will give substantial profit.

  4. Ubiquitous healthy diatoms in the deep sea confirms deep carbon injection by the biological pump

    NASA Astrophysics Data System (ADS)

    Agustí, Susana; González-Gordillo, Jose I.; Vaqué, Dolors; Estrada, Marta; Cerezo, Maria I.; Salazar, Guillem; Gasol, Josep M.; Duarte, Carlos M.

    2016-04-01

    The role of the ocean as a sink for CO2 is partially dependent on the downward transport of phytoplankton cells packaged within fast-sinking particles. However, whether such fast-sinking mechanisms deliver fresh organic carbon down to the deep bathypelagic sea and whether this mechanism is prevalent across the ocean awaits confirmation. Photosynthetic plankton, directly responsible for trapping CO2 in organic form in the surface layer, are a key constituent of the flux of sinking particles and are assumed to die and become detritus upon leaving the photic layer. Research in the 1960-70's reported the occasional presence of well-preserved phytoplankton cells in the deep ocean, but these observations, which could signal at rapid sinking rates, were considered anecdotal. Using new developments we tested the presence of healthy phytoplankton cells in the deep sea (2000 to 4000 m depth) along the Malaspina 2010 Circumnavigation Expedition, a global expedition sampling the bathypelagic zone of the Atlantic, Indian and Pacific Oceans. In particular, we used a new microplankton sampling device, the Bottle-Net, 16S rDNA sequences, flow cytometric counts, vital stains and experiments to explore the abundance and health status of photosynthetic plankton cells between 2,000 and 4,000 m depth along the Circumnavigation track. We described the community of microplankton (> 20μm) found at the deep ocean (2000-4000 m depth), surprisingly dominated by phytoplankton, and within this, by diatoms. Moreover, we report the ubiquitous presence of healthy photosynthetic cells, dominated by diatoms, down to 4,000 m in the deep dark sea. Decay experiments with surface phytoplankton suggested that the large proportion (18%) of healthy photosynthetic cells observed, on average, in the dark ocean, requires transport times from few days to few weeks, corresponding to sinking rates of 124 to 732 m d-1, comparable to those of fast sinking aggregates and faecal pellets. These results confirm the

  5. Deep sea AUV navigation using multiple acoustic beacons

    NASA Astrophysics Data System (ADS)

    Ji, Da-xiong; Song, Wei; Zhao, Hong-yu; Liu, Jian

    2016-04-01

    Navigation is a critical requirement for the operation of Autonomous Underwater Vehicles (AUVs). To estimate the vehicle position, we present an algorithm using an extended Kalman filter (EKF) to integrate dead-reckoning position with acoustic ranges from multiple beacons pre-deployed in the operating environment. Owing to high latency, variable sound speed multipath transmissions and unreliability in acoustic measurements, outlier recognition techniques are proposed as well. The navigation algorithm has been tested by the recorded data of deep sea AUV during field operations in a variety of environments. Our results show the improved performance over prior techniques based on position computation.

  6. Space Suit Technologies Protect Deep-Sea Divers

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Working on NASA missions allows engineers and scientists to hone their skills. Creating devices for the high-stress rigors of space travel pushes designers to their limits, and the results often far exceed the original concepts. The technologies developed for the extreme environment of space are often applicable here on Earth. Some of these NASA technologies, for example, have been applied to the breathing apparatuses worn by firefighters, the fire-resistant suits worn by racecar crews, and, most recently, the deep-sea gear worn by U.S. Navy divers.

  7. Meteoroid ablation spheres from deep-sea sediments

    NASA Technical Reports Server (NTRS)

    Blanchard, M. B.; Brownlee, D. E.; Bunch, T. E.; Hodge, P. W.; Kyte, F. T.

    1980-01-01

    The paper deals with an examination of spheres that are magnetically extracted from mid-Pacific abyssal clays that are up to half a million years old. The spheres are divided into three groups using their dominant mineralogy - namely, iron, glassy, and silicate. Most spheres were formed from particles that completely melted as they separated from their parent meteoroids during the ablation process. It is concluded that the mineralogy and composition of the deep-sea spheres are identical in many respects to the meteorite fusion crusts, laboratory-created ablation debris, and the ablated interplanetary dust particles in the stratospheric collection.

  8. Paleoceanographic implications of Miocene deep-sea hiatuses.

    USGS Publications Warehouse

    Keller, G.; Barron, J.A.

    1983-01-01

    Miocene paleoceanographic evolution exhibits major changes resulting from the opening and closing of passages, the subsequent changes in oceanic circulation, and development of major Antarctic glaciation. The consequences and timing of these events can be observed in variations in the distribution of deep-sea hiatuses, sedimentation patterns, and biogeographic distribution of planktic organisms. The main aspects of the present oceanic circulation system and sediment distribution pattern were established by 13.5 to 12.5 Ma (hiatus NH 3), coincident with the establishment of a major East Antarctic ice cap. -from Authors

  9. Deep-Sea Mining: Integrating Geology, Oceanography, and Engineering

    NASA Astrophysics Data System (ADS)

    Meyer, F. Michael; Halbach, Peter E.; Martens, Peer N.; Hein, James R.; Scott, Steve

    2008-09-01

    Shaping the Future: Deep-Sea Minerals and Mining Congress; Aachen, Germany, 9-13 March 2008; A strong increase in the global demand for metallic raw materials, coupled with rising market prices, has heightened interest in marine seabed mineral deposits and the feasibility of their extraction for many marine scientists, engineers, and mining companies. This interest focuses not only on base and precious metals but also on strategically important elements needed for high-technology applications, such as cobalt, nickel, molybdenum, titanium, gallium, selenium, telurium, indium, and the rare earth elements.

  10. Migrations and growth of deep-sea lobsters, Homarus americanus.

    PubMed

    Cooper, R A; Uzmann, J R

    1971-01-22

    In distinct contrast to the restricted movements of coastal stocks of lobsters (Homarus americanus), those inhabiting the outer continental shelf undertake extensive seasonal migrations. Of 5710 tagged lobsters released on the outer continental shelf off New England from April 1968 to June 1969, 400 had been recaptured by April 1970. The distribution of the recoveries demonstrated shoalward migration in spring and summer and a return to the edge of the shelf in fall and winter. Deep-sea lobsters have a faster rate of growth than coastal lobsters; growth increments at molting and the frequency of molting are greater.

  11. Deep-sea methane seep sediments in the Okhotsk Sea sustain diverse and abundant anammox bacteria.

    PubMed

    Shao, Sudong; Luan, Xiwu; Dang, Hongyue; Zhou, Haixia; Zhao, Yakun; Liu, Haitao; Zhang, Yunbo; Dai, Lingqing; Ye, Ying; Klotz, Martin G

    2014-02-01

    Marginal sea methane seep sediments sustain highly productive chemosynthetic ecosystems and are hotspots of intense biogeochemical cycling. Rich methane supply stimulates rapid microbial consumption of oxygen; these systems are thus usually hypoxic to anoxic. This and reported evidence for resident nitrogen fixation suggest the presence of an anaerobic ammonium-oxidizing (anammox) bacterial community in methane seep sediments. To test this hypothesis, we employed detection of genes encoding 16S rRNA gene and hydrazine dehydrogenase (hzo) to investigate the structure, abundance and distribution of the anammox bacterial community in the methane seep sediments of the Okhotsk Sea. Diverse complements of Candidatus Scalindua-related 16S rRNA and hzo gene sequences were obtained. Most of the deep-sea sites harbored abundant hzo genes with copy numbers as high as 10(7)  g(-1) sediment. In general, anammox bacterial signatures were significantly more abundant in the deep-water sediments. Sediment porewater NO3-, NOx- (i.e. NO3- + NO2-), NOx-/NH4+ and sediment silt content correlated with in situ distribution patterns of anammox bacterial marker genes, likely because they determine anammox substrate availability and sediment geochemistry, respectively. The abundance and distribution of anammox bacterial gene markers indicate a potentially significant contribution of anammox bacteria to the marine N cycle in the deep-sea methane seep sediments.

  12. Global ocean conveyor lowers extinction risk in the deep sea

    USGS Publications Warehouse

    Henry, Lea-Anne; Frank, Norbert; Hebbeln, Dierk; Weinberg, Claudia; Robinson, Laura; van de Flierdt, Tina; Dahl, Mikael; Douarin, Melanie; Morrison, Cheryl; Correa, Matthias Lopez; Rogers, Alex D.; Ruckelshausen, Mario; Roberts, J. Murray

    2014-01-01

    General paradigms of species extinction risk are urgently needed as global habitat loss and rapid climate change threaten Earth with what could be its sixth mass extinction. Using the stony coral Lophelia pertusa as a model organism with the potential for wide larval dispersal, we investigated how the global ocean conveyor drove an unprecedented post-glacial range expansion in Earth׳s largest biome, the deep sea. We compiled a unique ocean-scale dataset of published radiocarbon and uranium-series dates of fossil corals, the sedimentary protactinium–thorium record of Atlantic meridional overturning circulation (AMOC) strength, authigenic neodymium and lead isotopic ratios of circulation pathways, and coral biogeography, and integrated new Bayesian estimates of historic gene flow. Our compilation shows how the export of Southern Ocean and Mediterranean waters after the Younger Dryas 11.6 kyr ago simultaneously triggered two dispersal events in the western and eastern Atlantic respectively. Each pathway injected larvae from refugia into ocean currents powered by a re-invigorated AMOC that led to the fastest postglacial range expansion ever recorded, covering 7500 km in under 400 years. In addition to its role in modulating global climate, our study illuminates how the ocean conveyor creates broad geographic ranges that lower extinction risk in the deep sea.

  13. Amphipods on a deep-sea hydrothermal treadmill

    NASA Astrophysics Data System (ADS)

    Kaartvedt, S.; Van Dover, C. L.; Mullineaux, L. S.; Wiebe, P. H.; Bollens, S. M.

    1994-01-01

    Conspicuous swarms of a pardaliscid amphipod were observed at about 2520 and 2580 m depth in the East Pacific Rise vent field during dives with the submersible Alvin. Swarms occurred in association with mussels, clams and tubeworms, and were located above, and immediately downstream of cracks with emanating hydrothermal water. Numerical density sometimes exceeded 1000 individuals 1 -1, which is 3 orders of magnitude greater than any previous report on pelagic crustaceans from the deep sea. The amphipods, however, were not obligatory swarmers, and thin-layered shoals and scattered individuals were observed. Orientation of individuals was often polarized as they headed into the venting flow, swimming vigorously at 5-10 cm s -1 to maintain their position in the current. Retention within the preferred habitat requires an average swimming speed corresponding to the average current speed, suggesting a sustained swimming of > 10 body lengths s -1. These observations contrast with the general concept of low swimming activity in deep-sea crustaceans.

  14. Symbioses of methanotrophs and deep-sea mussels (Mytilidae: Bathymodiolinae).

    PubMed

    DeChaine, Eric G; Cavanaugh, Colleen M

    2006-01-01

    The symbioses between invertebrates and chemosynthetic bacteria allow both host and symbiont to colonize and thrive in otherwise inhospitable deep-sea habitats. Given the global distribution of the bathymodioline symbioses, this association is an excellent model for evaluating co-speciation and evolution of symbioses. Thus far, the methanotroph and chemoautotroph endosymbionts of mussels are tightly clustered within two independent clades of gamma Proteobacteria, respectively. Further physiological and genomic studies will elucidate the ecological and evolutionary roles that these bacterial clades play in the symbiosis and chemosynthetic community. Due to the overall abundance of the methanotrophic symbioses at hydrothermal vents and hydrocarbon seeps, they likely play a significant, but as of yet unquantified, role in the biogeochemical cycling of methane. With this in mind, the search for methanotrophic symbioses should not be restricted to these known deep-sea habitats, but rather should be expanded to include methane-rich coastal marine and freshwater environments inhabited by methanotrophs and bivalves. Our current understanding of the bathymodioline symbioses provides a strong foundation for future explorations into the origin, ecology, and evolution of methanotroph symbioses, which are now becoming possible through a combination of classical and advanced molecular techniques.

  15. Activity rhythms in the deep-sea: a chronobiological approach.

    PubMed

    Aguzzi, Jacopo; Company, Joan Batista; Costa, Corrado; Menesatti, Paolo; Garcia, Jose Antonio; Bahamon, Nixon; Puig, Pere; Sarda, Francesc

    2011-01-01

    Ocean waters deeper than 200 m cover 70% of the Earth's surface. Light intensity gets progressively weaker with increasing depth and internal tides or inertial currents may be the only remaining zeitgebers regulating biorhythms in deep-sea decapods. Benthopelagic coupling, exemplified by vertically moving shrimps within the water column, may also act as a source of indirect synchronisation to the day-night cycle for species living in permanently dark areas. At the same time, seasonal rhythms in growth and reproduction may be an exogenous response to spring-summer changes in upper layer productivity (via phytoplankton) or, alternatively, may be provoked by the synchronisation mediated by an endogenous controlling mechanism (via melatonin). In our review, we will focus on the behavioural rhythms of crustacean decapods inhabiting depths where the sun light is absent. Potential scenarios for future research on deep-sea decapod behaviour are suggested by new in situ observation technologies. Permanent video observatories are, to date, one of the most important tools for marine chronobiology in terms of species recognition and animals' movement tracking.

  16. Global ocean conveyor lowers extinction risk in the deep sea

    NASA Astrophysics Data System (ADS)

    Henry, Lea-Anne; Frank, Norbert; Hebbeln, Dierk; Wienberg, Claudia; Robinson, Laura; van de Flierdt, Tina; Dahl, Mikael; Douarin, Mélanie; Morrison, Cheryl L.; López Correa, Matthias; Rogers, Alex D.; Ruckelshausen, Mario; Roberts, J. Murray

    2014-06-01

    General paradigms of species extinction risk are urgently needed as global habitat loss and rapid climate change threaten Earth with what could be its sixth mass extinction. Using the stony coral Lophelia pertusa as a model organism with the potential for wide larval dispersal, we investigated how the global ocean conveyor drove an unprecedented post-glacial range expansion in Earth's largest biome, the deep sea. We compiled a unique ocean-scale dataset of published radiocarbon and uranium-series dates of fossil corals, the sedimentary protactinium-thorium record of Atlantic meridional overturning circulation (AMOC) strength, authigenic neodymium and lead isotopic ratios of circulation pathways, and coral biogeography, and integrated new Bayesian estimates of historic gene flow. Our compilation shows how the export of Southern Ocean and Mediterranean waters after the Younger Dryas 11.6 kyr ago simultaneously triggered two dispersal events in the western and eastern Atlantic respectively. Each pathway injected larvae from refugia into ocean currents powered by a re-invigorated AMOC that led to the fastest postglacial range expansion ever recorded, covering 7500 km in under 400 years. In addition to its role in modulating global climate, our study illuminates how the ocean conveyor creates broad geographic ranges that lower extinction risk in the deep sea.

  17. Adaptation to deep-sea methane seeps from Cretaceous shallow-water black shale environments?

    NASA Astrophysics Data System (ADS)

    Kiel, Steffen; Wiese, Frank; Titus, Alan

    2013-04-01

    Sulfide-enriched environments in shallow water were considered as sites where animals acquire pre-adaptations enabling them to colonize deep-sea hydrothermal vents and seeps or where they survived extinction events in their deep-sea habitats. Here we present upper Cenomanian (early Late Cretaceous) shallow-water seep communities from the Tropic Shale in the Western Interior Seaway, USA, that lived during a time of extremely warm deep-water temperatures, which supposedly facilitates adaptations to the deep sea, and time-equivalent with a period of widespread oceanic and photic zone anoxia (OAE 2) that supposedly extinguished deep-water vent and seep faunas. Contrary to the expectation, the taxa inhabiting the Tropic Shale seeps were not found at any coeval or younger deep-water seep or vent deposit. This suggests that (i) pre-adaptations for living at deep-sea vents and seeps do not evolve at shallow-water methane seeps, and probably also not in sulfide-rich shallow-water environments in general; (ii) a low temperature gradient from shallow to deep water does not facilitate onshore-offshore adaptations to deep-sea vents and seeps; and (iii) shallow-water seeps did not act as refuges for deep-sea vent and seep animals. We hypothesize that the vast majority of adaptations to successfully colonize deep-sea vents and seeps are acquired below the photic zone.

  18. Activity syndromes and metabolism in giant deep-sea isopods

    NASA Astrophysics Data System (ADS)

    Wilson, Alexander D. M.; Szekeres, Petra; Violich, Mackellar; Gutowsky, Lee F. G.; Eliason, Erika J.; Cooke, Steven J.

    2017-03-01

    Despite growing interest, the behavioural ecology of deep-sea organisms is largely unknown. Much of this scarcity in knowledge can be attributed to deepwater animals being secretive or comparatively 'rare', as well as technical difficulties associated with accessing such remote habitats. Here we tested whether two species of giant marine isopod (Bathynomus giganteus, Booralana tricarinata) captured from 653 to 875 m in the Caribbean Sea near Eleuthera, The Bahamas, exhibited an activity behavioural syndrome across two environmental contexts (presence/absence of food stimulus) and further whether this syndrome carried over consistently between sexes. We also measured routine metabolic rate and oxygen consumption in response to a food stimulus in B. giganteus to assess whether these variables are related to individual differences in personality. We found that both species show an activity syndrome across environmental contexts, but the underlying mechanistic basis of this syndrome, particularly in B. giganteus, is unclear. Contrary to our initial predictions, neither B. giganteus nor B. tricarinata showed any differences between mean expression of behavioural traits between sexes. Both sexes of B. tricarinata showed strong evidence of an activity syndrome underlying movement and foraging ecology, whereas only male B. giganteus showed evidence of an activity syndrome. Generally, individuals that were more active and bolder, in a standard open arena test were also more active when a food stimulus was present. Interestingly, individual differences in metabolism were not related to individual differences in behaviour based on present data. Our study provides the first measurements of behavioural syndromes and metabolism in giant deep-sea isopods.

  19. Temporal latitudinal-gradient dynamics and tropical instability of deep-sea species diversity

    USGS Publications Warehouse

    Yasuhara, Moriaki; Hunt, G.; Cronin, T. M.; Okahashi, H.

    2009-01-01

    A benthic microfaunal record from the equatorial Atlantic Ocean over the past four glacial-interglacial cycles was investigated to understand temporal dynamics of deep-sea latitudinal species diversity gradients (LSDGs). The results demonstrate unexpected instability and high amplitude fluctuations of species diversity in the tropical deep ocean that are correlated with orbital-scale oscillations in global climate: Species diversity is low during glacial and high during interglacial periods. This implies that climate severely influences deep-sea diversity, even at tropical latitudes, and that deep-sea LSDGs, while generally present for the last 36 million years, were weakened or absent during glacial periods. Temporally dynamic LSDGs and unstable tropical diversity require reconsideration of current ecological hypotheses about the generation and maintenance of biodiversity as they apply to the deep sea, and underscore the potential vulnerability and conservation importance of tropical deep-sea ecosystems.

  20. Ultra-deep sequencing of foraminiferal microbarcodes unveils hidden richness of early monothalamous lineages in deep-sea sediments.

    PubMed

    Lecroq, Béatrice; Lejzerowicz, Franck; Bachar, Dipankar; Christen, Richard; Esling, Philippe; Baerlocher, Loïc; Østerås, Magne; Farinelli, Laurent; Pawlowski, Jan

    2011-08-09

    Deep-sea floors represent one of the largest and most complex ecosystems on Earth but remain essentially unexplored. The vastness and remoteness of this ecosystem make deep-sea sampling difficult, hampering traditional taxonomic observations and diversity assessment. This problem is particularly true in the case of the deep-sea meiofauna, which largely comprises small-sized, fragile, and difficult-to-identify metazoans and protists. Here, we introduce an ultra-deep sequencing-based metagenetic approach to examine the richness of benthic foraminifera, a principal component of deep-sea meiofauna. We used Illumina sequencing technology to assess foraminiferal richness in 31 unsieved deep-sea sediment samples from five distinct oceanic regions. We sequenced an extremely short fragment (36 bases) of the small subunit ribosomal DNA hypervariable region 37f, which has been shown to accurately distinguish foraminiferal species. In total, we obtained 495,978 unique sequences that were grouped into 1,643 operational taxonomic units, of which about half (841) could be reliably assigned to foraminifera. The vast majority of the operational taxonomic units (nearly 90%) were either assigned to early (ancient) lineages of soft-walled, single-chambered (monothalamous) foraminifera or remained undetermined and yet possibly belong to unknown early lineages. Contrasting with the classical view of multichambered taxa dominating foraminiferal assemblages, our work reflects an unexpected diversity of monothalamous lineages that are as yet unknown using conventional micropaleontological observations. Although we can only speculate about their morphology, the immense richness of deep-sea phylotypes revealed by this study suggests that ultra-deep sequencing can improve understanding of deep-sea benthic diversity considered until now as unknowable based on a traditional taxonomic approach.

  1. Modelling the circulation and deep water formation in the Labrador Sea: sensitivity to Nordic Sea exchange

    NASA Astrophysics Data System (ADS)

    Czeschel, L.; Böning, C. W.

    2003-04-01

    Using an eddy-permitting model of the North Atlantic Ocean (part of the FLAME hierarchy) we investigate the impact of variable freshwater fluxes on the circulation, deep convection and the mixing between the boundary currents and the interior of the Labrador Sea. In this study, we use different forcing functions at the northern boundary (70N) to simulate variable freshwater (heat) exchanges with the Nordic Seas. In contrast to restoring to a climatology in a sponge layer, model versions with a prescribed streamfunction in an open boundary formulation give a better agreement with observational estimates of the circulation in this area. Varying the strength of the streamfunction at the northern boundary leads to fluctuations in the transport of the western boundary currents (East/West Greenland Current and Labrador Current) and thus to different freshwater budgets in the Labrador Sea.

  2. Characterization of bacterial diversity associated with deep sea ferromanganese nodules from the South China Sea.

    PubMed

    Zhang, De-Chao; Liu, Yan-Xia; Li, Xin-Zheng

    2015-09-01

    Deep sea ferromanganese (FeMn) nodules contain metallic mineral resources and have great economic potential. In this study, a combination of culture-dependent and culture-independent (16S rRNA genes clone library and pyrosequencing) methods was used to investigate the bacterial diversity in FeMn nodules from Jiaolong Seamount, the South China Sea. Eleven bacterial strains including some moderate thermophiles were isolated. The majority of strains belonged to the phylum Proteobacteria; one isolate belonged to the phylum Firmicutes. A total of 259 near full-length bacterial 16S rRNA gene sequences in a clone library and 67,079 valid reads obtained using pyrosequencing indicated that members of the Gammaproteobacteria dominated, with the most abundant bacterial genera being Pseudomonas and Alteromonas. Sequence analysis indicated the presence of many organisms whose closest relatives are known manganese oxidizers, iron reducers, hydrogen-oxidizing bacteria and methylotrophs. This is the first reported investigation of bacterial diversity associated with deep sea FeMn nodules from the South China Sea.

  3. Microbial Evolution at High Pressure: Deep Sea and Laboratory Studies

    NASA Astrophysics Data System (ADS)

    Bartlett, D. H.

    2011-12-01

    Elevated hydrostatic pressures are present in deep-sea and deep-Earth environments where this physical parameter has influenced the evolution and characteristics of life. Piezophilic (high-pressure-adapted) microbes have been isolated from diverse deep-sea settings, and would appear likely to occur in deep-subsurface habitats as well. In order to discern the factors enabling life at high pressure my research group has explored these adaptations at various levels, most recently including molecular analyses of deep-sea trench communities, and through the selective evolution of the model microbe Escherichia coli in the laboratory to progressively higher pressures. Much of the field work has focused on the microbes present in the deeper portions of the Puerto Rico Trench (PRT)and in the Peru-Chile Trench (PCT), from 6-8.5 km below the sea surface (~60-85 megapascals pressure). Culture-independent phylogenetic data on the Bacteria and Archaea present on particles or free-living, along with data on the microeukarya present was complemented with genomic analyses and the isolation and characterization of microbes in culture. Metagenomic analyses of the PRT revealed increased genome sizes and an overrepresentation at depth of sulfatases for the breakdown of sulfated polysaccharides and specific categories of transporters, including those associated with the transport of diverse cations or carboxylate ions, or associated with heavy metal resistance. Single-cell genomic studies revealed several linneages which recruited to the PRT metagenome far better than existing marine microbial genome sequences. analyses. Novel high pressure culture approaches have yielded new piezophiles including species preferring very low nutrient levels, those living off of hydrocarbons, and those adapted to various electron donor/electron acceptor combinations. In order to more specifically focus on functions enabling life at increased pressure selective evolution experiments were performed with

  4. Automated Video Quality Assessment for Deep-Sea Video

    NASA Astrophysics Data System (ADS)

    Pirenne, B.; Hoeberechts, M.; Kalmbach, A.; Sadhu, T.; Branzan Albu, A.; Glotin, H.; Jeffries, M. A.; Bui, A. O. V.

    2015-12-01

    Video provides a rich source of data for geophysical analysis, often supplying detailed information about the environment when other instruments may not. This is especially true of deep-sea environments, where direct visual observations cannot be made. As computer vision techniques improve and volumes of video data increase, automated video analysis is emerging as a practical alternative to labor-intensive manual analysis. Automated techniques can be much more sensitive to video quality than their manual counterparts, so performing quality assessment before doing full analysis is critical to producing valid results.Ocean Networks Canada (ONC), an initiative of the University of Victoria, operates cabled ocean observatories that supply continuous power and Internet connectivity to a broad suite of subsea instruments from the coast to the deep sea, including video and still cameras. This network of ocean observatories has produced almost 20,000 hours of video (about 38 hours are recorded each day) and an additional 8,000 hours of logs from remotely operated vehicle (ROV) dives. We begin by surveying some ways in which deep-sea video poses challenges for automated analysis, including: 1. Non-uniform lighting: Single, directional, light sources produce uneven luminance distributions and shadows; remotely operated lighting equipment are also susceptible to technical failures. 2. Particulate noise: Turbidity and marine snow are often present in underwater video; particles in the water column can have sharper focus and higher contrast than the objects of interest due to their proximity to the light source and can also influence the camera's autofocus and auto white-balance routines. 3. Color distortion (low contrast): The rate of absorption of light in water varies by wavelength, and is higher overall than in air, altering apparent colors and lowering the contrast of objects at a distance.We also describe measures under development at ONC for detecting and mitigating

  5. Deep oceanic currents and sea floor interactions offshore SE Africa

    NASA Astrophysics Data System (ADS)

    Raisson, François; Cazzola, Carlo; Ferry, Jean-Noel

    2016-04-01

    The Pamela Research program, which involves Total and Ifremer and their associated partners (French Universities, CNRS, IFPEN), is currently working to acquire new multidisciplinary data in the Mozambique Channel, in order to improve our knowledge and use this area as "laboratory" for comprehension of sedimentary/stratigraphical/geodynamical/structural and biological processes. The area comprised between the austral ocean and the southern tip of the African continent is a major place for Atlantic and Indian waters exchange, with high impact on the global climate (de Rujiter et al., 1999, Beal et al., 2011). Its prolongation toward the Mozambique Channel is a great playground to study effects of bottom currents on the sea floor. In this synthesis, we compile information about the major oceanic currents that occur at different water depth in the area, and we started listing the main published or ongoing studies, some of them in the scope of the Pamela project, related to sea floor interactions with bottom currents. These interactions are characterized by erosional features: submarine erosions, truncations, stratigraphic hiatuses, associated to depositional features: various types of contouritic drifts, sediment waves, asymmetric turbiditic levees etc. (Simpson et al., 1974, Uenzelmann-Neben et al., 2007, Uenzelmann-Neben & Huhn, 2009, Palermo et al., 2014). Movements of the main water masses in the Mozambique basin are strongly driven by thermohaline circulation but also sea floor topography and coast configuration: the Mozambique Current is not a persistent current but composed by southward moving anticyclonic eddies (De Rujiter et al., 2002, Ridderinkhof & de Rujiter, 2003, Swart et al., 2010, Halo et al., 2014). Deep currents flow northward along the western edge of the Mozambique basin: the North Atlantic Deep Waters (NADW) and the Antarctic Intermediate Waters (AAIW) flow along the Mozambican continental slope and form the Mozambique Undercurrent. A portion of

  6. Development of a multi-locus sequence typing scheme for avian isolates of Pasteurella multocida.

    PubMed

    Subaaharan, S; Blackall, L L; Blackall, P J

    2010-03-24

    A total of 63 isolates of Pasteurella multocida from Australian poultry, all associated with fowl cholera outbreaks, and three international reference strains, representing the three subspecies within P. multocida were used to develop a multi-locus sequence typing scheme. Primers were designed for conserved regions of seven house-keeping enzymes -adk, est, gdh, mdh, pgi, pmi and zwf - and internal fragments of 570-784 bp were sequenced for all isolates and strains. The number of alleles at the different loci ranged from 11 to 20 and a total of 29 allelic profiles or sequence types were recognised amongst the 66 strains. There was a strong concordance between the MLST data and the existing multi-locus enzyme electrophoresis and ribotyping data. When used to study a sub-set of isolates with a known detailed epidemiological history, the MLST data matched the results given by restriction endonuclease analysis, pulsed-field gel electrophoresis, ribotyping and REP-PCR. The MLST scheme provides a high level of resolution and is an excellent tool for studying the population structure and epidemiology of P. multocida.

  7. Deep-sea foraging behavior: its bathymetric potential in the fossil record.

    PubMed

    Kitchell, J A; Kitchell, J F; Clark, D L; Dangeard, L

    1978-06-16

    Spiral and meander foraging traces in the deep sea are not distributed in proportion to assumed food availability. Data collected by means of deep-sea photography failed to reveal a bathymetric gradient in behavioral complexity or sensitivity. The foraging paradigm developed by numerous trace fossil studies does not adequately predict the modern environment.

  8. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Submarine and deep sea cable expense. 32.6424 Section 32.6424 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine...

  9. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Submarine and deep sea cable expense. 32.6424 Section 32.6424 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine...

  10. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Submarine and deep sea cable expense. 32.6424 Section 32.6424 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine...

  11. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Submarine and deep sea cable expense. 32.6424 Section 32.6424 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine...

  12. 47 CFR 32.6424 - Submarine and deep sea cable expense.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Submarine and deep sea cable expense. 32.6424 Section 32.6424 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... Submarine and deep sea cable expense. (a) This account shall include expenses associated with submarine...

  13. Potential Health Benefits of Deep Sea Water: A Review

    PubMed Central

    Jaafar, A. B.; Mahdzir, A.; Musa, M. N.

    2016-01-01

    Deep sea water (DSW) commonly refers to a body of seawater that is pumped up from a depth of over 200 m. It is usually associated with the following characteristics: low temperature, high purity, and being rich with nutrients, namely, beneficial elements, which include magnesium, calcium, potassium, chromium, selenium, zinc, and vanadium. Less photosynthesis of plant planktons, consumption of nutrients, and organic decomposition have caused lots of nutrients to remain there. Due to this, DSW has potential to become a good source for health. Research has proven that DSW can help overcome health problems especially related to lifestyle-associated diseases such as cardiovascular disease, diabetes, obesity, cancer, and skin problems. This paper reviews the potential health benefits of DSW by referring to the findings from previous researches. PMID:28105060

  14. Catalysis of carbon monoxide methanation by deep sea manganate minerals

    NASA Technical Reports Server (NTRS)

    Cabrera, A. L.; Maple, M. B.; Arrhenius, G.

    1990-01-01

    The catalytic activity of deep sea manganese nodule minerals for the methanation of carbon monoxide was measured with a microcatalytic technique between 200 and 460 degrees C. The manganate minerals were activated at 248 degrees C by immersion into a stream of hydrogen in which pulses of carbon monoxide were injected. Activation energies for the methanation reaction and hydrogen desorption from the manganate minerals were obtained and compared with those of pure nickel. Similar energy values indicate that the activity of the nodule materials for the reaction appears to be related to the amount of reducible transition metals present in the samples (ca. 11 wt.-%). Since the activity of the nodule minerals per gram is comparable to that of pure nickel, most of the transition metal ions located between manganese oxide layers appear to be exposed and available to catalyze the reaction.

  15. Microbiology to 10,500 meters in the deep sea.

    PubMed

    Yayanos, A A

    1995-01-01

    Microorganisms in the deep sea live at high pressures, low and high temperatures, and in darkness. These parameters and their food supply govern their lives. The study of these creatures gives us an opportunity to see how life processes work at some of the highest temperatures and pressures of the biosphere. Cultured bacterial isolates can grow to over 100 MPa at 2 degrees C and to over 40 MPa at over 100 degrees C. These cultures comprise the foundation for the study of the molecular biology and biotechnology of these isolates. The PTk diagram shows how temperature and pressure affect the growth rate of a bacterium and helps in the search for relationships among bacteria from habitats differing in temperature and pressure.

  16. Potential Health Benefits of Deep Sea Water: A Review.

    PubMed

    Mohd Nani, Samihah Zura; Majid, F A A; Jaafar, A B; Mahdzir, A; Musa, M N

    2016-01-01

    Deep sea water (DSW) commonly refers to a body of seawater that is pumped up from a depth of over 200 m. It is usually associated with the following characteristics: low temperature, high purity, and being rich with nutrients, namely, beneficial elements, which include magnesium, calcium, potassium, chromium, selenium, zinc, and vanadium. Less photosynthesis of plant planktons, consumption of nutrients, and organic decomposition have caused lots of nutrients to remain there. Due to this, DSW has potential to become a good source for health. Research has proven that DSW can help overcome health problems especially related to lifestyle-associated diseases such as cardiovascular disease, diabetes, obesity, cancer, and skin problems. This paper reviews the potential health benefits of DSW by referring to the findings from previous researches.

  17. Abyssal and deep circulation in the Eastern Mediterranean Sea (Ionian Sea)

    NASA Astrophysics Data System (ADS)

    Artale, Vincenzo; Bensi, Manuel; Falcini, Federico; Marullo, Salvatore; Rubino, Angelo

    2016-04-01

    In the mid-1990s, experimental evidences on the Eastern Mediterranean Transient (EMT) were presented and it was shown that the Mediterranean abyssal circulation is not in a steady state but can be subjected to episodic sudden changes (Roether et al., 1996). In the last 10 years the Ionian Sea, the central and deepest part of the Mediterranean Sea, was subjected to relevant scientific interests from a theoretical and experimental point of view. Among these, there is the discovery of the BiOS (Bimodal Oscillating System), one new mechanism that drives a periodic (almost decadal) redistribution of surface and subsurface waters in the Eastern Mediterranean, with considerable feedbacks in the variability of the deep-water formation both in the southern Adriatic and in the Levantine and Aegean sub-basins (Gačić et al., 2010). In the Ionian Sea, numerous recent observational campaigns have been conducted to investigate the behaviour of deep and abyssal waters, at depths between 2000-4000m that are comparable to the mean global ocean depth (Rubino and Hainbucher, 2007; Bensi et al., 2013). There, advection, diffusion and vertical stability of the water masses can assume an important role on the internal quasi-periodical variability, creating the preconditions for catastrophic events such as the EMT or reversals of the Ionian circulation (Pisacane et al., 2006). Since there are no significant deep heat sources in the world ocean, waters that fill the deep ocean can only return to the sea surface as a result of downward mixing of heat from the sea surface to the bottom and vice versa and this occurs through eddy diffusion. Along our presentation, mainly through the analysis of the deepest CTD casts taken from 2009 to 2011 in the eastern basins and in particular in the Ionian Sea, we will show a significant change in the deep thermohaline structure (including its biogeochemical and hydrological characteristics), giving an indication on the time scale of the renewal of deep

  18. Beta-diversity on deep-sea wood falls reflects gradients in energy availability.

    PubMed

    McClain, Craig; Barry, James

    2014-01-01

    Wood falls on the deep-sea floor represent a significant source of energy into the food-limited deep sea. Unique communities of primarily wood- and sulfide-obligate species form on these wood falls. However, little is known regarding patterns and drivers of variation in the composition of wood fall communities through space and time, and thus, how wood falls contribute to deep-sea biodiversity. Eighteen Acacia logs varying in size were placed and retrieved after five years at a 3200 m site in the Pacific Ocean. We found that the taxonomic composition and structure of deep-sea wood fall communities varied considerably and equated with considerable differences in energy usage and availability. Our findings suggest that natural variability in wood falls may contribute significantly to deep-sea diversity.

  19. Virtual Investigations of an Active Deep Sea Volcano

    NASA Astrophysics Data System (ADS)

    Sautter, L.; Taylor, M. M.; Fundis, A.; Kelley, D. S.; Elend, M.

    2013-12-01

    Axial Seamount, located on the Juan de Fuca spreading ridge 300 miles off the Oregon coast, is an active volcano whose summit caldera lies 1500 m beneath the sea surface. Ongoing construction of the Regional Scale Nodes (RSN) cabled observatory by the University of Washington (funded by the NSF Ocean Observatories Initiative) has allowed for exploration of recent lava flows and active hydrothermal vents using HD video mounted on the ROVs, ROPOS and JASON II. College level oceanography/marine geology online laboratory exercises referred to as Online Concept Modules (OCMs) have been created using video and video frame-captured mosaics to promote skill development for characterizing and quantifying deep sea environments. Students proceed at their own pace through a sequence of short movies with which they (a) gain background knowledge, (b) learn skills to identify and classify features or biota within a targeted environment, (c) practice these skills, and (d) use their knowledge and skills to make interpretations regarding the environment. Part (d) serves as the necessary assessment component of the laboratory exercise. Two Axial Seamount-focused OCMs will be presented: 1) Lava Flow Characterization: Identifying a Suitable Cable Route, and 2) Assessing Hydrothermal Vent Communities: Comparisons Among Multiple Sulfide Chimneys.

  20. Deep structure and isostasy of the central Scotia Sea

    NASA Astrophysics Data System (ADS)

    Teterin, D. E.; Dubinin, E. P.; Udintsev, G. B.

    2015-07-01

    About 30 Ma ago in the Early Oligocene, the Drake Passage started to open and the Scotia lithospheric plate started to form. Although extensively studied during the past decade, the tectonic structure and evolution of the plate are still largely unclear. According to present-day notions, three large blocks—western, central, and eastern—are distinguished within the plate by the morphological features of undersea topography and anomalous geophysical fields in different reductions. From the standpoint of the origin and evolution, the central block is most interesting. In this work, we have studied the peculiar features of the deep structure and mechanism of isostatic equilibration for the central part of this plate using density modeling and cross-spectral analyzing. The density model has been constructed along the free-air gravity profile that intersects the central part of the Scotia Sea from the southeast to the northwest. The model estimates of crustal density are slightly lower than the average density of the oceanic crust and vary within 2.65 to 2.75 g/cm3. The transfer functions between the bathymetry and free-air gravity anomalies (gravitational admittance) have been calculated. By comparing the predicted and empirical transfer functions, we determined the mechanism of isostatic compensation and estimated the depths of the compensating boundaries. Together with the results of morphological analysis on undersea topography and geophysical fields (Teterin et al., 2015), these estimates suggest that the central Scotia Sea probably followed a different evolution scenario than the commonly accepted spreading model. This part of the Scotia Sea is probably a large fragment of the continental bridge that connected the South America with Antarctic and sank due to the heating and extension of the continental lithosphere.

  1. Widespread Miocene deep-sea hiatuses: coincidence with periods of global cooling.

    USGS Publications Warehouse

    Barron, J.A.; Keller, G.

    1982-01-01

    High-resolution biostratigraphic analyses of Miocene deep-sea cores reveal eight intervals of widespread hiatuses in the world ocean. In complete sections these hiatuses correspond to intervals of cool faunal and floral assemblages, rapid enrichment of delta 18O, and sea-level regressions. These factors suggest that Miocene deep-sea hiatuses result from an increased intensity of circulation and corrosiveness of bottom currents during periods of increased polar refrigeration.-Authors

  2. Simply actuated closure for a pressure vessel - Design for use to trap deep-sea animals

    NASA Technical Reports Server (NTRS)

    Yayanos, A. A.

    1977-01-01

    A pressure vessel is described that can be closed by a single translational motion within 1 sec. The vessel is a key component of a trap for small marine animals and operates automatically on the sea floor. As the vessel descends to the sea floor, it is subjected both internally and externally to the high pressures of the deep sea. The mechanism for closing the pressure vessel on the sea floor is activated by the timed release of the ballast which was used to sink the trap. As it rises to the sea surface, the internal pressure of the vessel remains near the value present on the sea floor. The pressure vessel has been used in simulated ocean deployments and in the deep ocean (9500 m) with a 75%-85% retention of the deep-sea pressure. Nearly 100% retention of pressure can be achieved by using an accumulator filled with a gas.

  3. A multi-locus approach to barcoding in the Anopheles strodei subgroup (Diptera: Culicidae)

    PubMed Central

    2013-01-01

    Background The ability to successfully identify and incriminate pathogen vectors is fundamental to effective pathogen control and management. This task is confounded by the existence of cryptic species complexes. Molecular markers can offer a highly effective means of species identification in such complexes and are routinely employed in the study of medical entomology. Here we evaluate a multi-locus system for the identification of potential malaria vectors in the Anopheles strodei subgroup. Methods Larvae, pupae and adult mosquitoes (n = 61) from the An. strodei subgroup were collected from 21 localities in nine Brazilian states and sequenced for the COI, ITS2 and white gene. A Bayesian phylogenetic approach was used to describe the relationships in the Strodei Subgroup and the utility of COI and ITS2 barcodes was assessed using the neighbor joining tree and “best close match” approaches. Results Bayesian phylogenetic analysis of the COI, ITS2 and white gene found support for seven clades in the An. strodei subgroup. The COI and ITS2 barcodes were individually unsuccessful at resolving and identifying some species in the Subgroup. The COI barcode failed to resolve An. albertoi and An. strodei but successfully identified approximately 92% of all species queries, while the ITS2 barcode failed to resolve An. arthuri and successfully identified approximately 60% of all species queries. A multi-locus COI-ITS2 barcode, however, resolved all species in a neighbor joining tree and successfully identified all species queries using the “best close match” approach. Conclusions Our study corroborates the existence of An. albertoi, An. CP Form and An. strodei in the An. strodei subgroup and identifies four species under An. arthuri informally named A-D herein. The use of a multi-locus barcode is proposed for species identification, which has potentially important utility for vector incrimination. Individuals previously found naturally infected with Plasmodium

  4. Community structure of archaea from deep-sea sediments of the South China Sea.

    PubMed

    Wang, Peng; Li, Tao; Hu, Anyi; Wei, Yuli; Guo, Wenting; Jiao, Nianzhi; Zhang, Chuanlun

    2010-11-01

    Using the archaeal 16S rRNA gene, we determined the community structures of archaea of subseafloor sediments (∼9-11 m below seafloor) from two geographically distant cores (MD05-2896, south, water depth 1,657 m; MD05-2902, north, water depth 3,697 m) in the South China Sea. Euryarchaeota accounted for 61.4% of total archaeal clone libraries at MD05-2896 and 56.2% at MD05-2902. At both locations, the Euryarchaeota-related sequences were dominated by Marine Benthic Group D, Terrestrial Miscellaneous Eryarchaeotal Group, and South African GoldMine Euryarchaeotal Group; the Crenarchaeota-related sequences were dominated by Marine Benthic Group B, Marine Group I, pSL12, and C3. The community structure showed no significant difference with depth at each location, suggesting the lack of stratification of archaeal populations in the deep-sea marine sediments in the South China Sea. On the other hand, the community structure is significantly different between the two sites, which may be related to geographical difference in the South China Sea.

  5. Radiocarbon in the Weddell Sea as observed in a deep-sea coral and in krill

    SciTech Connect

    Michel, R.L.; Druffel, E.M.

    1983-03-01

    Radiocarbon mesurements were performed on krill and coral samples collected from the Weddell Sea during IWSOE '80. These are the first radiocarbon measurements available from this area since 1973. These data reveal carbon-14 levels for Weddell surface water and southern Weddell Shelf water. These data indicate that the radiocarbon levels in surface waters in 1980 were the same or slightly lower than those present in 1973. In addition, an unusually low ..delta../sup 14/C value for shelf water (from coral) at 500 m is evidence that Warm Deep Water (WDW) may penetrate much further and more frequently onto the shelf region than had previously been expected.

  6. Persistence of Pristine Deep-Sea Coral Gardens in the Mediterranean Sea (SW Sardinia)

    PubMed Central

    Bo, Marzia; Bavestrello, Giorgio; Angiolillo, Michela; Calcagnile, Lucio; Canese, Simonepietro; Cannas, Rita; Cau, Alessandro; D’Elia, Marisa; D’Oriano, Filippo; Follesa, Maria Cristina; Quarta, Gianluca; Cau, Angelo

    2015-01-01

    Leiopathes glaberrima is a tall arborescent black coral species structuring important facies of the deep-sea rocky bottoms of the Mediterranean Sea that are severely stifled by fishing activities. At present, however, no morphological in vivo description, ecological characterization, age dating and evaluation of the possible conservation actions have ever been made for any population of this species in the basin. A dense coral population was reported during two Remotely Operated Vehicle (ROV) surveys conducted on a rocky bank off the SW coasts of Sardinia (Western Mediterranean Sea). L. glaberrima forms up to 2 m-tall colonies with a maximal observed basal diameter of nearly 7 cm. The radiocarbon dating carried out on a colony from this site with a 4 cm basal diameter revealed an approximately age of 2000 years. Considering the size-frequency distribution of the colonies in the area it is possible to hypothesize the existence of other millennial specimens occupying a supposedly very stable ecosystem. The persistence of this ecosystem is likely guaranteed by the heterogeneous rocky substrate hosting the black coral population that represents a physical barrier against the mechanical impacts acted on the surrounding muddy areas, heavily exploited as trawling fishing grounds. This favorable condition, together with the existence of a nursery area for catsharks within the coral ramifications and the occurrence of a meadow of the now rare soft bottom alcyonacean Isidella elongata in small surviving muddy enclaves, indicates that this ecosystem have to be considered a pristine Mediterranean deep-sea coral sanctuary that would deserve special protection. PMID:25790333

  7. Increasing presence of Arctic Ocean deep waters in the Greenland Sea

    NASA Astrophysics Data System (ADS)

    Somavilla Cabrillo, Raquel; Schauer, Ursula; Budeus, Gedeon

    2013-04-01

    Deep convection has been known to provide the coldest and freshest waters to the deep Greenland Sea, whose properties are balanced with the advection of warmer and saltier waters from the deep Arctic Ocean. However, during the last three decades, deep convection has come to a halt in the Greenland Sea. As previously reported and updated in this work through the analysis of the free available hydrographic data in the central Greenland Sea and in the Arctic Ocean from 1950 to 2010 (Pangaea and ICES data bases), as a consequence of this, two major hydrographic changes are observed: (1) the appearance and deepening of an intermediate temperature maximum and (2) a continuous warming and saltening of the deep Greenland Sea. The origin of both findings is found in the advection of Arctic Ocean deep waters from the Amerasian and Eurasian basins, respectively, into the central Greenland Sea. Associated to the first, a temperature increase of 0.35° C from 1993 to 2009 is observed at 1700 m. Below 2000 m, the temperature and salinity have increased at a mean rate of 0.136° C/decade and 0.01decade-1 in the last three decades. Overall, the stop of deep convection and the advection of Arctic Ocean deep waters result among the highest deep warming and saltening trends of the World Ocean in the Greenland Sea. In addition to the described update of the state of these changes, two new accomplishments are fulfilled in this study. First, in absence of deep convection, the continuous changing of the thermohaline properties of the deep Greenland Sea requires exchanges with adjacent ocean basins. This scenario enables us the estimation of the necessary transports from the deep Arctic to explain the observed changes. A transport of Eurasian Basin Deep Water of 0.31±0.04 Sv is obtained. Secondly, the warming and saltening of the deep Greenland Sea contributes, as any other ocean basin, to the World Ocean heat content and sea level rise. The estimation of these contributions shows larger

  8. Measuring Meiotic Crossovers via Multi-Locus Genotyping of Single Pollen Grains in Barley.

    PubMed

    Dreissig, Steven; Fuchs, Jörg; Cápal, Petr; Kettles, Nicola; Byrne, Ed; Houben, Andreas

    2015-01-01

    The detection of meiotic crossovers in crop plants currently relies on scoring DNA markers in a segregating population or cytological visualization. We investigated the feasibility of using flow-sorted haploid nuclei, Phi29 DNA polymerase-based whole-genome-amplification (WGA) and multi-locus KASP-genotyping to measure meiotic crossovers in individual barley pollen grains. To demonstrate the proof of concept, we used 24 gene-based physically mapped single nucleotide polymorphisms to genotype the WGA products of 50 single pollen nuclei. The number of crossovers per chromosome, recombination frequencies along chromosome 3H and segregation distortion were analysed and compared to a doubled haploid (DH) population of the same genotype. The number of crossovers and chromosome wide recombination frequencies show that this approach is able to produce results that resemble those obtained from other methods in a biologically meaningful way. Only the segregation distortion was found to be lower in the pollen population than in DH plants.

  9. Causes and Consequences of Multi-Locus Imprinting Disturbances in Humans.

    PubMed

    Sanchez-Delgado, Marta; Riccio, Andrea; Eggermann, Thomas; Maher, Eamonn R; Lapunzina, Pablo; Mackay, Deborah; Monk, David

    2016-07-01

    Eight syndromes are associated with the loss of methylation at specific imprinted loci. There has been increasing evidence that these methylation defects in patients are not isolated events occurring at a given disease-associated locus but that some of these patients may have multi-locus imprinting disturbances (MLID) affecting additional imprinted regions. With the recent advances in technology, methylation profiling has revealed that imprinted loci represent only a small fraction of the methylation differences observed between the gametes. To figure out how imprinting anomalies occur at multiple imprinted domains, we have to understand the interplay between DNA methylation and histone modifications in the process of selective imprint protection during pre-implantation reprogramming, which, if disrupted, leads to these complex imprinting disorders (IDs).

  10. Deep-Sea, Deep-Sequencing: Metabarcoding Extracellular DNA from Sediments of Marine Canyons

    PubMed Central

    Guardiola, Magdalena; Uriz, María Jesús; Taberlet, Pierre; Coissac, Eric; Wangensteen, Owen Simon; Turon, Xavier

    2015-01-01

    Marine sediments are home to one of the richest species pools on Earth, but logistics and a dearth of taxonomic work-force hinders the knowledge of their biodiversity. We characterized α- and β-diversity of deep-sea assemblages from submarine canyons in the western Mediterranean using an environmental DNA metabarcoding. We used a new primer set targeting a short eukaryotic 18S sequence (ca. 110 bp). We applied a protocol designed to obtain extractions enriched in extracellular DNA from replicated sediment corers. With this strategy we captured information from DNA (local or deposited from the water column) that persists adsorbed to inorganic particles and buffered short-term spatial and temporal heterogeneity. We analysed replicated samples from 20 localities including 2 deep-sea canyons, 1 shallower canal, and two open slopes (depth range 100–2,250 m). We identified 1,629 MOTUs, among which the dominant groups were Metazoa (with representatives of 19 phyla), Alveolata, Stramenopiles, and Rhizaria. There was a marked small-scale heterogeneity as shown by differences in replicates within corers and within localities. The spatial variability between canyons was significant, as was the depth component in one of the canyons where it was tested. Likewise, the composition of the first layer (1 cm) of sediment was significantly different from deeper layers. We found that qualitative (presence-absence) and quantitative (relative number of reads) data showed consistent trends of differentiation between samples and geographic areas. The subset of exclusively benthic MOTUs showed similar patterns of β-diversity and community structure as the whole dataset. Separate analyses of the main metazoan phyla (in number of MOTUs) showed some differences in distribution attributable to different lifestyles. Our results highlight the differentiation that can be found even between geographically close assemblages, and sets the ground for future monitoring and conservation efforts on

  11. Deep-Sea, Deep-Sequencing: Metabarcoding Extracellular DNA from Sediments of Marine Canyons.

    PubMed

    Guardiola, Magdalena; Uriz, María Jesús; Taberlet, Pierre; Coissac, Eric; Wangensteen, Owen Simon; Turon, Xavier

    2015-01-01

    Marine sediments are home to one of the richest species pools on Earth, but logistics and a dearth of taxonomic work-force hinders the knowledge of their biodiversity. We characterized α- and β-diversity of deep-sea assemblages from submarine canyons in the western Mediterranean using an environmental DNA metabarcoding. We used a new primer set targeting a short eukaryotic 18S sequence (ca. 110 bp). We applied a protocol designed to obtain extractions enriched in extracellular DNA from replicated sediment corers. With this strategy we captured information from DNA (local or deposited from the water column) that persists adsorbed to inorganic particles and buffered short-term spatial and temporal heterogeneity. We analysed replicated samples from 20 localities including 2 deep-sea canyons, 1 shallower canal, and two open slopes (depth range 100-2,250 m). We identified 1,629 MOTUs, among which the dominant groups were Metazoa (with representatives of 19 phyla), Alveolata, Stramenopiles, and Rhizaria. There was a marked small-scale heterogeneity as shown by differences in replicates within corers and within localities. The spatial variability between canyons was significant, as was the depth component in one of the canyons where it was tested. Likewise, the composition of the first layer (1 cm) of sediment was significantly different from deeper layers. We found that qualitative (presence-absence) and quantitative (relative number of reads) data showed consistent trends of differentiation between samples and geographic areas. The subset of exclusively benthic MOTUs showed similar patterns of β-diversity and community structure as the whole dataset. Separate analyses of the main metazoan phyla (in number of MOTUs) showed some differences in distribution attributable to different lifestyles. Our results highlight the differentiation that can be found even between geographically close assemblages, and sets the ground for future monitoring and conservation efforts on

  12. A Brief Review of Bioactive Metabolites Derived from Deep-Sea Fungi

    PubMed Central

    Wang, Yan-Ting; Xue, Ya-Rong; Liu, Chang-Hong

    2015-01-01

    Deep-sea fungi, the fungi that inhabit the sea and the sediment at depths of over 1000 m below the surface, have become an important source of industrial, agricultural, and nutraceutical compounds based on their diversities in both structure and function. Since the first study of deep-sea fungi in the Atlantic Ocean at a depth of 4450 m was conducted approximately 50 years ago, hundreds of isolates of deep-sea fungi have been reported based on culture-dependent methods. To date more than 180 bioactive secondary metabolites derived from deep-sea fungi have been documented in the literature. These include compounds with anticancer, antimicrobial, antifungal, antiprotozoal, and antiviral activities. In this review, we summarize the structures and bioactivities of these metabolites to provide help for novel drug development. PMID:26213949

  13. A Brief Review of Bioactive Metabolites Derived from Deep-Sea Fungi.

    PubMed

    Wang, Yan-Ting; Xue, Ya-Rong; Liu, Chang-Hong

    2015-07-23

    Deep-sea fungi, the fungi that inhabit the sea and the sediment at depths of over 1000 m below the surface, have become an important source of industrial, agricultural, and nutraceutical compounds based on their diversities in both structure and function. Since the first study of deep-sea fungi in the Atlantic Ocean at a depth of 4450 m was conducted approximately 50 years ago, hundreds of isolates of deep-sea fungi have been reported based on culture-dependent methods. To date more than 180 bioactive secondary metabolites derived from deep-sea fungi have been documented in the literature. These include compounds with anticancer, antimicrobial, antifungal, antiprotozoal, and antiviral activities. In this review, we summarize the structures and bioactivities of these metabolites to provide help for novel drug development.

  14. Mechanism of Deep-Sea Fish α-Actin Pressure Tolerance Investigated by Molecular Dynamics Simulations

    PubMed Central

    Wakai, Nobuhiko; Takemura, Kazuhiro; Morita, Takami; Kitao, Akio

    2014-01-01

    The pressure tolerance of monomeric α-actin proteins from the deep-sea fish Coryphaenoides armatus and C. yaquinae was compared to that of non-deep-sea fish C. acrolepis, carp, and rabbit/human/chicken actins using molecular dynamics simulations at 0.1 and 60 MPa. The amino acid sequences of actins are highly conserved across a variety of species. The actins from C. armatus and C. yaquinae have the specific substitutions Q137K/V54A and Q137K/L67P, respectively, relative to C. acrolepis, and are pressure tolerant to depths of at least 6000 m. At high pressure, we observed significant changes in the salt bridge patterns in deep-sea fish actins, and these changes are expected to stabilize ATP binding and subdomain arrangement. Salt bridges between ATP and K137, formed in deep-sea fish actins, are expected to stabilize ATP binding even at high pressure. At high pressure, deep-sea fish actins also formed a greater total number of salt bridges than non-deep-sea fish actins owing to the formation of inter-helix/strand and inter-subdomain salt bridges. Free energy analysis suggests that deep-sea fish actins are stabilized to a greater degree by the conformational energy decrease associated with pressure effect. PMID:24465747

  15. Mechanism of deep-sea fish α-actin pressure tolerance investigated by molecular dynamics simulations.

    PubMed

    Wakai, Nobuhiko; Takemura, Kazuhiro; Morita, Takami; Kitao, Akio

    2014-01-01

    The pressure tolerance of monomeric α-actin proteins from the deep-sea fish Coryphaenoides armatus and C. yaquinae was compared to that of non-deep-sea fish C. acrolepis, carp, and rabbit/human/chicken actins using molecular dynamics simulations at 0.1 and 60 MPa. The amino acid sequences of actins are highly conserved across a variety of species. The actins from C. armatus and C. yaquinae have the specific substitutions Q137K/V54A and Q137K/L67P, respectively, relative to C. acrolepis, and are pressure tolerant to depths of at least 6000 m. At high pressure, we observed significant changes in the salt bridge patterns in deep-sea fish actins, and these changes are expected to stabilize ATP binding and subdomain arrangement. Salt bridges between ATP and K137, formed in deep-sea fish actins, are expected to stabilize ATP binding even at high pressure. At high pressure, deep-sea fish actins also formed a greater total number of salt bridges than non-deep-sea fish actins owing to the formation of inter-helix/strand and inter-subdomain salt bridges. Free energy analysis suggests that deep-sea fish actins are stabilized to a greater degree by the conformational energy decrease associated with pressure effect.

  16. Deep-sea water improves cardiovascular hemodynamics in Kurosawa and Kusanagi-Hypercholesterolemic (KHC) rabbits.

    PubMed

    Katsuda, Shin-Ichiro; Yasukawa, Takeshi; Nakagawa, Koji; Miyake, Masao; Yamasaki, Masao; Katahira, Kiyoaki; Mohri, Motohiko; Shimizu, Tsuyoshi; Hazama, Akihiro

    2008-01-01

    Deep-sea water is rich in minerals, e.g., Mg, Ca, and K which have been considered to be associated with prevention of cardiovascular disease. We investigated the effect of deep-sea water on cardiovascular hemodynamics in Kurosawa and Kusanagi-Hypercholesterolemic (KHC) rabbits. Deep-sea water was pumped in the offing of Cape Muroto in Japan and the mineral constituents were refined to a degree of hardness of 1,000. Twenty four 4-month-old KHC rabbits were given refined deep-sea water (n=12) and tap water (n=12) for 6 months. Pressure and flow waves at the ascending aorta were recorded under pentobarbital anesthesia. Systolic, diastolic, pulse and mean arterial pressures and total peripheral resistance were significantly lower in the deep-sea water group than in the control group. There were no significant differences in changes in serum lipid levels, plasma renin and angiotensin converting enzyme activities and electrolyte levels except for Mg(2+) after the feeding of the water between the two groups. A slight increase in serum Mg(2+) level in the deep-sea water group may not account for the inhibition of mild hypertension. From our results, we conclude that deep-sea water could improve cardiovascular hemodynamics, even though the factors which affect the blood pressure are still unknown.

  17. Optimization of DNA Extraction from Deep-sea Basalt

    NASA Astrophysics Data System (ADS)

    Wang, H.; Edwards, K. J.

    2007-12-01

    Studies on the microorganisms that inhabit deep-sea basalt can provide information on this dark ecosystem, which will contribution to our understanding of mass transformation and energy flow in the deep ocean. However, molecular methods for use with metal- and clay-rich rock materials such as basalt have not been suitably developed at present, yet are critically required in order to be able to fully evaluate the basalt biotope. For example, inefficient DNA extraction might lead to loss of information about important components of this community, and misinterpretation about the total community diversity and function. In order to investigate the effects of sample pretreated method, particle size, different DNA extraction methods and cell density on extracted DNA yields, two basalt samples were collected from the East Pacific Rise 9° N during research cruise AT11- 20 in Nov 2004. Basalt samples were crushed to different particle size, washed with ddH2O and 100% ethanol respectively, and autoclaved. Marinobacter aquaeolei cultures with different cell densities were inoculated into differently treated basalt samples. Pure culture and basalt samples without inoculation were used as positive and negative control to evaluate the extracting efficiency. FastDNA spin for soil kit, GeneClean for ancient DNA kit and UltraCleanTM soil DNA Kit are used for DNA extraction. Results showed that DNA yields increased with culture density. FastDNA spin for soil kit gave the highest DNA yields, which is almost 10 times more than that of UltraCleanTM soil DNA Kit. Ethanol washing and ddH2O washing did not make big difference to DNA yields. Mineral composition and surface areas might also affect DNA yields.

  18. Phylogenetic relationships in the family Streptomycetaceae using multi-locus sequence analysis.

    PubMed

    Labeda, David P; Dunlap, Christopher A; Rong, Xiaoying; Huang, Ying; Doroghazi, James R; Ju, Kou-San; Metcalf, William W

    2017-04-01

    The family Streptomycetaceae, notably species in the genus Streptomyces, have long been the subject of investigation due to their well-known ability to produce secondary metabolites. The emergence of drug resistant pathogens and the relative ease of producing genome sequences has renewed the importance of Streptomyces as producers of new natural products and resulted in revived efforts in isolating and describing strains from novel environments. A previous large study of the phylogeny in the Streptomycetaceae based on 16S rRNA gene sequences provided a useful framework for the relationships among species, but did not always have sufficient resolution to provide definitive identification. Multi-locus sequence analysis of 5 house-keeping genes has been shown to provide improved taxonomic resolution of Streptomyces species in a number of previous reports so a comprehensive study was undertaken to evaluate evolutionary relationships among species within the family Streptomycetaceae where type strains are available in the ARS Culture Collection or genome sequences are available in GenBank. The results of the analysis supported the distinctiveness of Kitasatospora and Streptacidiphilus as validly named genera since they cluster outside of the phylogenetic radiation of the genus Streptomyces. There is also support for the transfer of a number of Streptomyces species to the genus Kitasatospora as well for reducing at least 31 species clusters to a single taxon. The multi-locus sequence database resulting from the study is a useful tool for identification of new isolates and the phylogenetic analysis presented also provides a road map for planning future genome sequencing efforts in the Streptomycetaceae.

  19. Multi-locus estimates of population structure and migration in a fence lizard hybrid zone.

    PubMed

    Leaché, Adam D

    2011-01-01

    A hybrid zone between two species of lizards in the genus Sceloporus (S. cowlesi and S. tristichus) on the Mogollon Rim in Arizona provides a unique opportunity to study the processes of lineage divergence and merging. This hybrid zone involves complex interactions between 2 morphologically and ecologically divergent subspecies, 3 chromosomal groups, and 4 mitochondrial DNA (mtDNA) clades. The spatial patterns of divergence between morphology, chromosomes and mtDNA are discordant, and determining which of these character types (if any) reflects the underlying population-level lineages that are of interest has remained impeded by character conflict. The focus of this study is to estimate the number of populations interacting in the hybrid zone using multi-locus nuclear data, and to then estimate the migration rates and divergence time between the inferred populations. Multi-locus estimates of population structure and gene flow were obtained from 12 anonymous nuclear loci sequenced for 93 specimens of Sceloporus. Population structure estimates support two populations, and this result is robust to changes to the prior probability distribution used in the Bayesian analysis and the use of spatially-explicit or non-spatial models. A coalescent analysis of population divergence suggests that gene flow is high between the two populations, and that the timing of divergence is restricted to the Pleistocene. The hybrid zone is more accurately described as involving two populations belonging to S. tristichus, and the presence of S. cowlesi mtDNA haplotypes in the hybrid zone is an anomaly resulting from mitochondrial introgression.

  20. A climate-related oxidizing event in deep-sea sediment from the Bering Sea

    USGS Publications Warehouse

    Gardner, J.V.; Dean, W.E.; Klise, D.H.; Baldauf, J.G.

    1982-01-01

    Many cores from the deep basins of the Bering Sea have a thin oxidized zone within otherwise reduced sediment. This oxidized zone began to form about 6000 yr ago and represents an interval of about 3200 yr. Mineralogically, the oxidized and reduced sediments are similar, but chemically they differ. Concentrations of Fe and C are lower, and concentrations of Mn, Ba, Co, Mo, and Ni are higher in the oxidized than in the reduced sediment. Mn is enriched about 10-fold in the oxidized zone relative to its concentration in the reduced sediment, Mo about threefold, and Ba, Co, and Ni about twofold. These data suggest that the oxidized zone developed diagenetically as the result of the balance between the flux of organic matter and the available dissolved oxygen in bottom and interstitial waters. We propose that the Bering Sea was substantially ice covered when global glacial conditions prevailed. during the transition to global interglacial conditions, seasonal meltwater from thawing sea ice formed a lens of fresh water that decreased organic productivity. During the winter seasons, however, sea ice reformed and caused downwelling of dense, oxygen-rich waters to recharge bottom waters. The combination of lower organic productivity and more oxygen-rich bottom water allowed oxidized sediment to accumulate. Once full interglacial conditions were established, the volume of sea ice produced was insufficient to affect either productivity or the supply of dissolved oxygen and so bottom conditions again became reducing. Similar events probably occurred during the onset of global glacial conditions, and similar oxidized layers probably formed at these times. Such oxidized zones are highly unstable, however, in a reducing environment and, once buried beyond the influence of bacterial and infaunal activities, are depleted of their available oxygen and converted to reduced sediment. ?? 1982.

  1. Contrasting population histories of the deep-sea demersal fish, Lycodes matsubarai, in the Sea of Japan and the Sea of Okhotsk.

    PubMed

    Sakuma, Kay; Ueda, Yuji; Hamatsu, Tomonori; Kojima, Shigeaki

    2014-06-01

    Recent studies have revealed the impact of the drastic climate change during the last glacial period on coastal marine and anadromous species in the marginal seas of the northwestern Pacific Ocean; however, its influence on deep-sea species remains poorly understood. To compare the effects of the last glacial period on populations from the Sea of Japan and the Sea of Okhotsk, we examined the mitochondrial control region and cytochrome b gene sequences of Lycodes matsubarai, a deepsea demersal fish that inhabits these two seas. Our results showed clear genetic differentiation of populations between the two seas. The populations may have diverged during the last glacial period, probably as a result of vicariance due to the drastic sea level change. The population in the Sea of Okhotsk was larger than that in the Sea of Japan, but suddenly decreased after the last glacial period. However, the Sea of Japan population expanded after the last glacial period, coincident with high levels of oxygenation in deep-sea areas. These results elucidate regional-scale impacts of climate change on deep-sea organisms.

  2. The geological history of deep-sea colonization by echinoids: roles of surface productivity and deep-water ventilation

    PubMed Central

    Smith, Andrew B; Stockley, Bruce

    2005-01-01

    The origins and geological history of the modern fauna of deep-sea echinoids is explored using a combination of palaeontological and molecular data. We demonstrate that, whereas generalist omnivores have migrated into the deep sea in low numbers over the past 200 Myr, there was a short time-interval between approximately 75 and 55 Myr when the majority of specialist detritivore clades independently migrated off-shelf. This coincides with a marked increase in seasonality, continental run-off and surface water productivity, and suggests that increasing organic carbon delivery into ocean basins was an important controlling factor. Oceanic anoxic events, by contrast, appear to have played a subsidiary role in controlling deep-sea diversity. PMID:15888420

  3. Improving power and accuracy of genome-wide association studies via a multi-locus mixed linear model methodology.

    PubMed

    Wang, Shi-Bo; Feng, Jian-Ying; Ren, Wen-Long; Huang, Bo; Zhou, Ling; Wen, Yang-Jun; Zhang, Jin; Dunwell, Jim M; Xu, Shizhong; Zhang, Yuan-Ming

    2016-01-20

    Genome-wide association studies (GWAS) have been widely used in genetic dissection of complex traits. However, common methods are all based on a fixed-SNP-effect mixed linear model (MLM) and single marker analysis, such as efficient mixed model analysis (EMMA). These methods require Bonferroni correction for multiple tests, which often is too conservative when the number of markers is extremely large. To address this concern, we proposed a random-SNP-effect MLM (RMLM) and a multi-locus RMLM (MRMLM) for GWAS. The RMLM simply treats the SNP-effect as random, but it allows a modified Bonferroni correction to be used to calculate the threshold p value for significance tests. The MRMLM is a multi-locus model including markers selected from the RMLM method with a less stringent selection criterion. Due to the multi-locus nature, no multiple test correction is needed. Simulation studies show that the MRMLM is more powerful in QTN detection and more accurate in QTN effect estimation than the RMLM, which in turn is more powerful and accurate than the EMMA. To demonstrate the new methods, we analyzed six flowering time related traits in Arabidopsis thaliana and detected more genes than previous reported using the EMMA. Therefore, the MRMLM provides an alternative for multi-locus GWAS.

  4. Taxonomic evaluation of putative Streptomyces scabiei strains held in the ARS (NRRL) Culture Collection using multi-locus sequence analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multi-locus sequence analysis has been demonstrated to be a useful tool for identification of Streptomyces species and was previously applied to phylogenetically differentiate the type strains of species pathogenic on potatoes (Solanum tuberosum L.). The ARS Culture Collection (NRRL) contains 43 str...

  5. Improving power and accuracy of genome-wide association studies via a multi-locus mixed linear model methodology

    PubMed Central

    Wang, Shi-Bo; Feng, Jian-Ying; Ren, Wen-Long; Huang, Bo; Zhou, Ling; Wen, Yang-Jun; Zhang, Jin; Dunwell, Jim M.; Xu, Shizhong; Zhang, Yuan-Ming

    2016-01-01

    Genome-wide association studies (GWAS) have been widely used in genetic dissection of complex traits. However, common methods are all based on a fixed-SNP-effect mixed linear model (MLM) and single marker analysis, such as efficient mixed model analysis (EMMA). These methods require Bonferroni correction for multiple tests, which often is too conservative when the number of markers is extremely large. To address this concern, we proposed a random-SNP-effect MLM (RMLM) and a multi-locus RMLM (MRMLM) for GWAS. The RMLM simply treats the SNP-effect as random, but it allows a modified Bonferroni correction to be used to calculate the threshold p value for significance tests. The MRMLM is a multi-locus model including markers selected from the RMLM method with a less stringent selection criterion. Due to the multi-locus nature, no multiple test correction is needed. Simulation studies show that the MRMLM is more powerful in QTN detection and more accurate in QTN effect estimation than the RMLM, which in turn is more powerful and accurate than the EMMA. To demonstrate the new methods, we analyzed six flowering time related traits in Arabidopsis thaliana and detected more genes than previous reported using the EMMA. Therefore, the MRMLM provides an alternative for multi-locus GWAS. PMID:26787347

  6. Marine culturable yeasts in deep-sea hydrothermal vents: species richness and association with fauna.

    PubMed

    Burgaud, Gaëtan; Arzur, Danielle; Durand, Lucile; Cambon-Bonavita, Marie-Anne; Barbier, Georges

    2010-07-01

    Investigations of the diversity of culturable yeasts at deep-sea hydrothermal sites have suggested possible interactions with endemic fauna. Samples were collected during various oceanographic cruises at the Mid-Atlantic Ridge, South Pacific Basins and East Pacific Rise. Cultures of 32 isolates, mostly associated with animals, were collected. Phylogenetic analyses of 26S rRNA gene sequences revealed that the yeasts belonged to Ascomycota and Basidiomycota phyla, with the identification of several genera: Rhodotorula, Rhodosporidium, Candida, Debaryomyces and Cryptococcus. Those genera are usually isolated from deep-sea environments. To our knowledge, this is the first report of yeasts associated with deep-sea hydrothermal animals.

  7. An abyssal mobilome: viruses, plasmids and vesicles from deep-sea hydrothermal vents.

    PubMed

    Lossouarn, Julien; Dupont, Samuel; Gorlas, Aurore; Mercier, Coraline; Bienvenu, Nadege; Marguet, Evelyne; Forterre, Patrick; Geslin, Claire

    2015-12-01

    Mobile genetic elements (MGEs) such as viruses, plasmids, vesicles, gene transfer agents (GTAs), transposons and transpovirions, which collectively represent the mobilome, interact with cellular organisms from all three domains of life, including those thriving in the most extreme environments. While efforts have been made to better understand deep-sea vent microbial ecology, our knowledge of the mobilome associated with prokaryotes inhabiting deep-sea hydrothermal vents remains limited. Here we focus on the abyssal mobilome by reviewing accumulating data on viruses, plasmids and vesicles associated with thermophilic and hyperthermophilic Bacteria and Archaea present in deep-sea hydrothermal vents.

  8. Geologic evolution of the Bering Sea Komandorksy deep basin

    SciTech Connect

    Bogdanov, N.A.

    1986-07-01

    The deep-water Komandorsky basin is located in the southwestern part of the Bering Sea. On the east, it is separated from the Aleutian basin by the submerged Shirshov Ridge; on the west, it is bordered by structures of the north Kamchatka accretionary prism. The Komandorsky basin is characterized by strongly dissected relief of it acoustic basement, which is overlain by a 1.5 to 2.0-km thick sedimentary cover. The western part of the basin is occupied by a rift zone, which is characterized by modern seismicity and high heat flow. It is considered to be the axial zone of Miocene-Pleistocene spreading. On the north terrace of the Komandorsky island arc, traced active volcanos provide evidence that subduction is occurring under the arc from the north. The spreading rift zone is reflected on the continent in Miocene-Pleistocene volcanic rocks, characterized by typical oceanic tholeiitic composition. The Komandorsky basin formed as a result of spreading during the Maestrichtian. Spreading within the basin occurred during the early and middle Oligocene and the late Miocene. East and west of the spreading axis, accretionary prisms formed. The latter are observed along the western flank of the Shirshov Ridge and on the eastern sides of the Kamchatka Peninsula and Koraginsky Island.

  9. Carbon dioxide sequestration in deep-sea basalt.

    PubMed

    Goldberg, David S; Takahashi, Taro; Slagle, Angela L

    2008-07-22

    Developing a method for secure sequestration of anthropogenic carbon dioxide in geological formations is one of our most pressing global scientific problems. Injection into deep-sea basalt formations provides unique and significant advantages over other potential geological storage options, including (i) vast reservoir capacities sufficient to accommodate centuries-long U.S. production of fossil fuel CO2 at locations within pipeline distances to populated areas and CO2 sources along the U.S. west coast; (ii) sufficiently closed water-rock circulation pathways for the chemical reaction of CO2 with basalt to produce stable and nontoxic (Ca(2+), Mg(2+), Fe(2+))CO(3) infilling minerals, and (iii) significant risk reduction for post-injection leakage by geological, gravitational, and hydrate-trapping mechanisms. CO2 sequestration in established sediment-covered basalt aquifers on the Juan de Fuca plate offer promising locations to securely accommodate more than a century of future U.S. emissions, warranting energized scientific research, technological assessment, and economic evaluation to establish a viable pilot injection program in the future.

  10. Pressure response in deep-sea piezophilic bacteria.

    PubMed

    Kato, C; Qureshi, M H

    1999-08-01

    Several piezophilic bacteria have been isolated from deep-sea environments under high hydrostatic pressure. Taxonomic studies of the isolates showed that the piezophilic bacteria are not widely distributed in terms of taxonomic positions, and all were assigned to particular branches of the Proteobacteria gamma-subgroup. A pressure-regulated operon from piezophilic bacteria of the genus Shewanella, S. benthica and S. violacea, was cloned and sequenced, and downstream of this operon another pressure regulated operon, cydD-C, was found. The cydD gene was found to be essential for the bacterial growth under high-pressure conditions, and the product of this gene was found to play a role in their respiratory system. Results obtained later indicated that the respiratory system in piezophilic bacteria may be important for survival in a high-pressure environment, and more studies focusing on other components of the respiratory chain have been conducted. These studies suggested that piezophilic bacteria are capable of changing their respiratory system in response to pressure conditions, and a proposed respiratory chain model has been suggested in this regard.

  11. Deep sea hydrothermal plumes and their interaction with oscillatory flows

    NASA Astrophysics Data System (ADS)

    Xu, Guangyu; di Iorio, Daniela

    2012-09-01

    The acoustic scintillation method is applied to the investigation and monitoring of a vigorous hydrothermal plume from Dante within the Main Endeavour vent field (MEF) in the Endeavour Ridge segment. A 40 day time series of the plume's vertical velocity and temperature fluctuations provides a unique opportunity to study deep sea plume dynamics in a tidally varying horizontal cross flow. An integral plume model that takes into account ambient stratification and horizontal cross flows is established from the conservation equations of mass, momentum and density deficit. Using a linear additive entrainment velocity in the model (E = αUm + βU⊥) that is a function of both the plume relative axial velocity (Um) and the relative ambient flow perpendicular to the plume (U⊥) gives consistent results to the experimental data, suggesting entrainment coefficients α = 0.1 and β = 0.6. Also from the integral model, the plume height in a horizontal cross flow (Ua) is shown to scale as 1.8B1/3Ua-1/3N-2/3 for 0.01 ≤ Ua ≤ 0.1 m/s where B is the initial buoyancy transport and N is the ambient stratification, both of which are assumed constant.

  12. Cellulomonas marina sp. nov., isolated from deep-sea water.

    PubMed

    Zhang, Limin; Xi, Lijun; Qiu, Danheng; Song, Lei; Dai, Xin; Ruan, Jisheng; Huang, Ying

    2013-08-01

    A bacterial strain FXJ8.089(T) was isolated from deep-sea water collected from the southwest Indian Ocean (49° 39' E 37° 47' S) at a depth of 2800 m, and its taxonomic position was investigated by a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain FXJ8.089(T) belonged to the genus Cellulomonas and had the highest similarities with Cellulomonas oligotrophica (96.9 %) and Cellulomonas aerilata (96.6 %). It contained MK-9(H4) as the predominant menaquinone. The polar lipids were diphosphatidylglycerol and phosphatidylinositol mannosides. The cell-wall peptidoglycan type was A4β with an interpeptide bridge L-Orn-D-Glu. The cell-wall sugars were glucose, mannose and ribose. The DNA G+C content was 70.3 mol%. The strain also showed a number of physiological and biochemical characteristics that were distinct from the closely related species. Based on phenotypic and genotypic data, strain FXJ8.089(T) (= CGMCC 4.6945(T) = DSM 24960(T)) represents a novel species of the genus Cellulomonas, for which the name Cellulomonas marina sp. nov. is proposed.

  13. Effect of surface mesoscale eddies on deep-sea currents and mixing in the northeastern South China Sea

    NASA Astrophysics Data System (ADS)

    Zhang, Yanwei; Liu, Zhifei; Zhao, Yulong; Li, Jianru; Liang, Xinfeng

    2015-12-01

    Recent studies suggest that deep-reaching surface-generated eddies result in anomalous current velocities in the deep sea, and ultimately lead to energy transfer from mesoscale to small-scale motions. Here we examine the influence of mesoscale eddies on deep-sea subinertial and near-inertial currents, and on possible enhanced oceanic mixing in the deep South China Sea (SCS). We analyzed current velocity data for nearly a full water column. Data were obtained using acoustic Doppler current profilers and recording current meters on a deep-sea mooring system at a depth of 2100 m in the northeastern SCS from October 2012 to May 2013. A highly nonlinear southwestward-propagating anticyclonic eddy was detected via a resolved sea-surface-level anomaly. This eddy induced pronounced subinertial currents with a characteristic time scale of 1-2 months and a maximum velocity of up to 0.2 m s-1 at the subsurface and 0.1 m s-1 at great depth. Near-inertial energy co-occurring with subinertial flows showed a distinctive vertical propagation trend during strong subinertial oscillations in the deep sea. During periods of strong subinertial and near-inertial kinetic energy, estimates of diapycnal diffusivity in the deep ocean showed approximately 10-fold enhancement, with a mean value of 1.2×10-3 m2 s-1 compared to the background value of 1.4×10-4 m2 s-1. The results provide observational evidence of the effect of surface-observed mesoscale motions on benthic currents and ocean mixing in the deep SCS.

  14. Sperm whale assessment in the Western Ionian Sea using acoustic data from deep sea observatories

    NASA Astrophysics Data System (ADS)

    Caruso, Francesco; Bellia, Giorgio; Beranzoli, Laura; De Domenico, Emilio; Larosa, Giuseppina; Marinaro, Giuditta; Papale, Elena; Pavan, Gianni; Pellegrino, Carmelo; Pulvirenti, Sara; Riccobene, Giorgio; Scandura, Danila; Sciacca, Virginia; Viola, Salvatore

    2015-04-01

    The Italian National Institute of Nuclear Physics (INFN) operates two deep sea infrastructures: Capo Passero, Western Ionian Sea 3,600 meters of depth, and Catania Wester Ionian Sea 2,100 m depth. At the two sites, several research observatories have been run: OnDE, NEMO-SN1, SMO, KM3NeT-Italia most of them jointly operated between INFN and INGV. In all these observatories, passive acoustic sensors (hydrophones) have been installed. Passive Acoustics Monitoring (PAM) is nowadays the main tool of the bioacoustics to study marine mammals. In particular, receiving the sounds emitted by cetaceans from a multi-hydrophones array installed in a cabled seafloor observatory, a research about the ecological dynamics of the species may be performed. Data acquired with the hydrophones installed aboard the OnDE, SMO and KM3NeT-Italia observatories will be reported. Thanks to acquired data, the acoustic presence of the sperm whales was assessed and studied for several years (2005:2013). An "ad hoc" algorithm was also developed to allow the automatic identification of the "clicks" emitted by the sperm whales and measure the size of detected animals. According to the results obtained, the sperm whale population in the area is well-distributed in size, sex and sexual maturity. Although specimens more than 14 meters of length (old males) seem to be absent.

  15. Effect of sea water interaction on strontium isotope composition of deep-sea basalts

    USGS Publications Warehouse

    Julius, Dasch E.; Hedge, C.E.; Dymond, J.

    1973-01-01

    Analyses of rim-to-interior samples of fresh tholeiitic pillow basalts, deuterically altered holocrystalline basalts, and older, weathered tholeiitic basalts from the deep sea indicate that 87Sr 86Sr ratios of the older basalts are raised by low temperature interaction with strontium dissolved in sea water. 87Sr 86Sr correlates positively with H2O in these basalts; however, there is little detectable modification of the strontium isotope composition in rocks with H2O contents less than 1%. The isotope changes appear to be a function of relatively long-term, low-temperature weathering, rather than high-temperature or deuteric alteration. Strontium abundance and isotopic data for these rocks suggest that strontium content is only slightly modified by interaction with sea water, and it is a relatively insensitive indicator of marine alteration. Average Rb-Sr parameters for samples of apparently unaltered basalt are: Rb = 1.11 ppm; Sr = 132 ppm; 87Sr 86Sr = 0.70247. ?? 1973.

  16. Modern Tasman Sea surface reservoir ages from deep-sea black corals

    NASA Astrophysics Data System (ADS)

    Komugabe, Aimée F.; Fallon, Stewart J.; Thresher, Ronald E.; Eggins, Stephen M.

    2014-01-01

    Marine reservoir ages are a key element in calculating and constraining uncertainty in radiocarbon age estimates and are also essential to better understand regional ocean circulation. In this study, we present a new method to reconstruct long-term, high-resolution sea surface reservoir ages based on analysis of the organic skeleton of deep-sea (560 m) black coral (Anthozoa, Antipatharia). Our results confirm that antipatharians are extremely slow growing (typical radial growth rate for a South Pacific specimen around 0.03 mm/yr). Coupled uranium series and radiocarbon measurements were made on black coral collected live from the Norfolk Ridge (north Tasman Sea) to provide the first modern reservoir ages for this region. At the Norfolk Ridge, the average reservoir age between 1790 AD and 1900 AD was ∼330 years. This was followed by a steep decrease over time of about 70 years to 1950 AD (our most modern value). This indicates an increase in surface ocean ventilation of water masses in this region. These results are consistent with observational studies for the early twentieth century, which suggest significant changes in regional circulation of the southwest pacific.

  17. Deep-sea macrourid fishes scavenge on plant material: Evidence from in situ observations

    NASA Astrophysics Data System (ADS)

    Jeffreys, Rachel M.; Lavaleye, Marc S. S.; Bergman, Magda J. N.; Duineveld, Gerard C. A.; Witbaard, Rob; Linley, Thom

    2010-04-01

    Deep-sea benthic communities primarily rely on an allochthonous food source. This may be in the form of phytodetritus or as food falls e.g. sinking carcasses of nekton or debris of marine macrophyte algae. Deep-sea macrourids are the most abundant demersal fish in the deep ocean. Macrourids are generally considered to be the apex predators/scavengers in deep-sea communities. Baited camera experiments and stable isotope analyses have demonstrated that animal carrion derived from the surface waters is an important component in the diets of macrourids; some macrourid stomachs also contained vegetable/plant material e.g. onion peels, oranges, algae. The latter observations led us to the question: is plant material an attractive food source for deep-sea scavenging fish? We simulated a plant food fall using in situ benthic lander systems equipped with a baited time-lapse camera. Abyssal macrourids and cusk-eels were attracted to the bait, both feeding vigorously on the bait, and the majority of the bait was consumed in <30 h. These observations indicate (1) plant material can produce an odour plume similar to that of animal carrion and attracts deep-sea fish, and (2) deep-sea fish readily eat plant material. This represents to our knowledge the first in situ documentation of deep-sea fish ingesting plant material and highlights the variability in the scavenging nature of deep-sea fishes. This may have implications for food webs in areas where macrophyte/seagrass detritus is abundant at the seafloor e.g. canyon systems and continental shelves close to seagrass meadows (Bahamas and Mediterranean).

  18. [Microbial diversity of deep-sea extremophiles--Piezophiles, Hyperthermophiles, and subsurface microorganisms].

    PubMed

    Kato, C; Takai, K

    2000-12-01

    Knowledge of our Planet's biosphere has increased tremendously during the last 10 to 20 years. In the field of Microbiology in particular, scientists have discovered novel "extremophiles", microorganisms capable of living in extreme environments such as highly acidic or alkaline conditions, at high salt concentration, with no oxygen, extreme temperatures (as low as -20 degrees C and as high as 300 degrees C), at high concentrations of heavy metals and in high pressure environments such as the deep-sea. It is apparent that microorganisms can exist in any extreme environment of the Earth, yet already scientists have started to look for life on other planets; the so-called "Exobiology" project. But as yet we have little knowledge of the deep-sea and subsurface biosphere of our own planet. We believe that we should elucidate the Biodiversity of Earth more thoroughly before exploring life on other planets, and these attempts would provide deeper insight into clarifying the existence of extraterrestrial life. We focused on two deep-sea extremophiles in this article; one is "Piezophiles", and another is "Hyperthermophiles". Piezophiles are typical microorganisms adapted to high-pressure and cold temperature environments, and located in deep-sea bottom. Otherwise, hyperthermophiles are living in high temperature environment, and located at around the hydrothermal vent systems in deep-sea. They are not typical deep-sea microorganisms, but they can grow well at high-pressure condition, just like piezophiles. Deming and Baross mentioned that most of the hyperthermophilic archaea isolated from deep-sea hydrothermal vents are able to grow under conditions of high temperature and pressure, and in most cases their optimal pressure for growth was greater than the environmental pressure they were isolated from. It is possible that originally their native environment may have been deeper than the sea floor and that there had to be a deeper biosphere. This implication suggests that

  19. Deep-sea bioluminescence blooms after dense water formation at the ocean surface.

    PubMed

    Tamburini, Christian; Canals, Miquel; Durrieu de Madron, Xavier; Houpert, Loïc; Lefèvre, Dominique; Martini, Séverine; D'Ortenzio, Fabrizio; Robert, Anne; Testor, Pierre; Aguilar, Juan Antonio; Samarai, Imen Al; Albert, Arnaud; André, Michel; Anghinolfi, Marco; Anton, Gisela; Anvar, Shebli; Ardid, Miguel; Jesus, Ana Carolina Assis; Astraatmadja, Tri L; Aubert, Jean-Jacques; Baret, Bruny; Basa, Stéphane; Bertin, Vincent; Biagi, Simone; Bigi, Armando; Bigongiari, Ciro; Bogazzi, Claudio; Bou-Cabo, Manuel; Bouhou, Boutayeb; Bouwhuis, Mieke C; Brunner, Jurgen; Busto, José; Camarena, Francisco; Capone, Antonio; Cârloganu, Christina; Carminati, Giada; Carr, John; Cecchini, Stefano; Charif, Ziad; Charvis, Philippe; Chiarusi, Tommaso; Circella, Marco; Coniglione, Rosa; Costantini, Heide; Coyle, Paschal; Curtil, Christian; Decowski, Patrick; Dekeyser, Ivan; Deschamps, Anne; Donzaud, Corinne; Dornic, Damien; Dorosti, Hasankiadeh Q; Drouhin, Doriane; Eberl, Thomas; Emanuele, Umberto; Ernenwein, Jean-Pierre; Escoffier, Stéphanie; Fermani, Paolo; Ferri, Marcelino; Flaminio, Vincenzo; Folger, Florian; Fritsch, Ulf; Fuda, Jean-Luc; Galatà, Salvatore; Gay, Pascal; Giacomelli, Giorgio; Giordano, Valentina; Gómez-González, Juan-Pablo; Graf, Kay; Guillard, Goulven; Halladjian, Garadeb; Hallewell, Gregory; van Haren, Hans; Hartman, Joris; Heijboer, Aart J; Hello, Yann; Hernández-Rey, Juan Jose; Herold, Bjoern; Hößl, Jurgen; Hsu, Ching-Cheng; de Jong, Marteen; Kadler, Matthias; Kalekin, Oleg; Kappes, Alexander; Katz, Uli; Kavatsyuk, Oksana; Kooijman, Paul; Kopper, Claudio; Kouchner, Antoine; Kreykenbohm, Ingo; Kulikovskiy, Vladimir; Lahmann, Robert; Lamare, Patrick; Larosa, Giuseppina; Lattuada, Dario; Lim, Gordon; Presti, Domenico Lo; Loehner, Herbert; Loucatos, Sotiris; Mangano, Salvatore; Marcelin, Michel; Margiotta, Annarita; Martinez-Mora, Juan Antonio; Meli, Athina; Montaruli, Teresa; Moscoso, Luciano; Motz, Holger; Neff, Max; Nezri, Emma Nuel; Palioselitis, Dimitris; Păvălaş, Gabriela E; Payet, Kevin; Payre, Patrice; Petrovic, Jelena; Piattelli, Paolo; Picot-Clemente, Nicolas; Popa, Vlad; Pradier, Thierry; Presani, Eleonora; Racca, Chantal; Reed, Corey; Riccobene, Giorgio; Richardt, Carsten; Richter, Roland; Rivière, Colas; Roensch, Kathrin; Rostovtsev, Andrei; Ruiz-Rivas, Joaquin; Rujoiu, Marius; Russo, Valerio G; Salesa, Francisco; Sánchez-Losa, Augustin; Sapienza, Piera; Schöck, Friederike; Schuller, Jean-Pierre; Schussler, Fabian; Shanidze, Rezo; Simeone, Francesco; Spies, Andreas; Spurio, Maurizio; Steijger, Jos J M; Stolarczyk, Thierry; Taiuti, Mauro G F; Toscano, Simona; Vallage, Bertrand; Van Elewyck, Véronique; Vannoni, Giulia; Vecchi, Manuela; Vernin, Pascal; Wijnker, Guus; Wilms, Jorn; de Wolf, Els; Yepes, Harold; Zaborov, Dmitry; De Dios Zornoza, Juan; Zúñiga, Juan

    2013-01-01

    The deep ocean is the largest and least known ecosystem on Earth. It hosts numerous pelagic organisms, most of which are able to emit light. Here we present a unique data set consisting of a 2.5-year long record of light emission by deep-sea pelagic organisms, measured from December 2007 to June 2010 at the ANTARES underwater neutrino telescope in the deep NW Mediterranean Sea, jointly with synchronous hydrological records. This is the longest continuous time-series of deep-sea bioluminescence ever recorded. Our record reveals several weeks long, seasonal bioluminescence blooms with light intensity up to two orders of magnitude higher than background values, which correlate to changes in the properties of deep waters. Such changes are triggered by the winter cooling and evaporation experienced by the upper ocean layer in the Gulf of Lion that leads to the formation and subsequent sinking of dense water through a process known as "open-sea convection". It episodically renews the deep water of the study area and conveys fresh organic matter that fuels the deep ecosystems. Luminous bacteria most likely are the main contributors to the observed deep-sea bioluminescence blooms. Our observations demonstrate a consistent and rapid connection between deep open-sea convection and bathypelagic biological activity, as expressed by bioluminescence. In a setting where dense water formation events are likely to decline under global warming scenarios enhancing ocean stratification, in situ observatories become essential as environmental sentinels for the monitoring and understanding of deep-sea ecosystem shifts.

  20. Deep-Sea Bioluminescence Blooms after Dense Water Formation at the Ocean Surface

    PubMed Central

    Tamburini, Christian; Canals, Miquel; Durrieu de Madron, Xavier; Houpert, Loïc; Lefèvre, Dominique; Martini, Séverine; D'Ortenzio, Fabrizio; Robert, Anne; Testor, Pierre; Aguilar, Juan Antonio; Samarai, Imen Al; Albert, Arnaud; André, Michel; Anghinolfi, Marco; Anton, Gisela; Anvar, Shebli; Ardid, Miguel; Jesus, Ana Carolina Assis; Astraatmadja, Tri L.; Aubert, Jean-Jacques; Baret, Bruny; Basa, Stéphane; Bertin, Vincent; Biagi, Simone; Bigi, Armando; Bigongiari, Ciro; Bogazzi, Claudio; Bou-Cabo, Manuel; Bouhou, Boutayeb; Bouwhuis, Mieke C.; Brunner, Jurgen; Busto, José; Camarena, Francisco; Capone, Antonio; Cârloganu, Christina; Carminati, Giada; Carr, John; Cecchini, Stefano; Charif, Ziad; Charvis, Philippe; Chiarusi, Tommaso; Circella, Marco; Coniglione, Rosa; Costantini, Heide; Coyle, Paschal; Curtil, Christian; Decowski, Patrick; Dekeyser, Ivan; Deschamps, Anne; Donzaud, Corinne; Dornic, Damien; Dorosti, Hasankiadeh Q.; Drouhin, Doriane; Eberl, Thomas; Emanuele, Umberto; Ernenwein, Jean-Pierre; Escoffier, Stéphanie; Fermani, Paolo; Ferri, Marcelino; Flaminio, Vincenzo; Folger, Florian; Fritsch, Ulf; Fuda, Jean-Luc; Galatà, Salvatore; Gay, Pascal; Giacomelli, Giorgio; Giordano, Valentina; Gómez-González, Juan-Pablo; Graf, Kay; Guillard, Goulven; Halladjian, Garadeb; Hallewell, Gregory; van Haren, Hans; Hartman, Joris; Heijboer, Aart J.; Hello, Yann; Hernández-Rey, Juan Jose; Herold, Bjoern; Hößl, Jurgen; Hsu, Ching-Cheng; de Jong, Marteen; Kadler, Matthias; Kalekin, Oleg; Kappes, Alexander; Katz, Uli; Kavatsyuk, Oksana; Kooijman, Paul; Kopper, Claudio; Kouchner, Antoine; Kreykenbohm, Ingo; Kulikovskiy, Vladimir; Lahmann, Robert; Lamare, Patrick; Larosa, Giuseppina; Lattuada, Dario; Lim, Gordon; Presti, Domenico Lo; Loehner, Herbert; Loucatos, Sotiris; Mangano, Salvatore; Marcelin, Michel; Margiotta, Annarita; Martinez-Mora, Juan Antonio; Meli, Athina; Montaruli, Teresa; Motz, Holger; Neff, Max; Nezri, Emma nuel; Palioselitis, Dimitris; Păvălaş, Gabriela E.; Payet, Kevin; Payre, Patrice; Petrovic, Jelena; Piattelli, Paolo; Picot-Clemente, Nicolas; Popa, Vlad; Pradier, Thierry; Presani, Eleonora; Racca, Chantal; Reed, Corey; Riccobene, Giorgio; Richardt, Carsten; Richter, Roland; Rivière, Colas; Roensch, Kathrin; Rostovtsev, Andrei; Ruiz-Rivas, Joaquin; Rujoiu, Marius; Russo, Valerio G.; Salesa, Francisco; Sánchez-Losa, Augustin; Sapienza, Piera; Schöck, Friederike; Schuller, Jean-Pierre; Schussler, Fabian; Shanidze, Rezo; Simeone, Francesco; Spies, Andreas; Spurio, Maurizio; Steijger, Jos J. M.; Stolarczyk, Thierry; Taiuti, Mauro G. F.; Toscano, Simona; Vallage, Bertrand; Van Elewyck, Véronique; Vannoni, Giulia; Vecchi, Manuela; Vernin, Pascal; Wijnker, Guus; Wilms, Jorn; de Wolf, Els; Yepes, Harold; Zaborov, Dmitry; De Dios Zornoza, Juan; Zúñiga, Juan

    2013-01-01

    The deep ocean is the largest and least known ecosystem on Earth. It hosts numerous pelagic organisms, most of which are able to emit light. Here we present a unique data set consisting of a 2.5-year long record of light emission by deep-sea pelagic organisms, measured from December 2007 to June 2010 at the ANTARES underwater neutrino telescope in the deep NW Mediterranean Sea, jointly with synchronous hydrological records. This is the longest continuous time-series of deep-sea bioluminescence ever recorded. Our record reveals several weeks long, seasonal bioluminescence blooms with light intensity up to two orders of magnitude higher than background values, which correlate to changes in the properties of deep waters. Such changes are triggered by the winter cooling and evaporation experienced by the upper ocean layer in the Gulf of Lion that leads to the formation and subsequent sinking of dense water through a process known as “open-sea convection”. It episodically renews the deep water of the study area and conveys fresh organic matter that fuels the deep ecosystems. Luminous bacteria most likely are the main contributors to the observed deep-sea bioluminescence blooms. Our observations demonstrate a consistent and rapid connection between deep open-sea convection and bathypelagic biological activity, as expressed by bioluminescence. In a setting where dense water formation events are likely to decline under global warming scenarios enhancing ocean stratification, in situ observatories become essential as environmental sentinels for the monitoring and understanding of deep-sea ecosystem shifts. PMID:23874425

  1. Natural Products from Deep-Sea-Derived Fungi ̶ a New Source of Novel Bioactive Compounds?

    PubMed

    Daletos, Georgios; Ebrahim, Weaam; Ancheeva, Elena; El-Neketi, Mona; Proksch, Peter

    2017-03-14

    Over the last two decades, deep-sea-derived fungi are considered to be a new source of pharmacologically active secondary metabolites for drug discovery mainly based on the underlying assumption that the uniqueness of the deep sea will give rise to equally unprecedented natural products. Indeed, up to now over 200 new metabolites have been identified from deep-sea fungi, which is in support of the statement made above. This review will summarize the new and/or bioactive compounds reported from deep-sea-derived fungi in the last six years (2010 - present) and will critically evaluate whether the data published so far really support the notion that these fungi are a promising source of new bioactive chemical entities.

  2. Biosurfactant-producing yeast isolated from Calyptogena soyoae (deep-sea cold-seep clam) in the deep sea.

    PubMed

    Konishi, Masaaki; Fukuoka, Tokuma; Nagahama, Takahiko; Morita, Tomotake; Imura, Tomohiro; Kitamoto, Dai; Hatada, Yuji

    2010-08-01

    We describe a detailed structure determination of biosurfactant produced by Pseudozyma hubeiensis SY62, which was newly isolated from Calyptogena soyoae (deep-sea cold-seep clam, Shirouri-gai) at 1156 m in Sagami bay. P. hubeiensis SY62 was taxonomically slightly different from the P. hubeiensis type strain, which produces biosurfactants. Glycolipid production by the strain was also slightly different from those of previously reported strains. BS productivity was estimated to be around 30 g/l from the weight of the crude extract. At least five different spots of glycolipid biosurfactants (BSs) were detected by TLC. Results of nuclear magnetic resonance spectroscopies indicated the major product, namely MEL-C (4-O-[4'-O-acetyl-2',3'-di-O-alka(e)noil-beta-d-mannopyranosyl]-d-erythritol), as a promising BS. By further structural determination, the major fatty acids of MEL-C were estimated to be saturated C(6), C(10), and C(12) acids, which were shorter than those of previously reported MEL-C. Furthermore, (1)H-NMR spectra implied the presence of C(2) acids as acyl groups. According to surface tension determination, the novel MEL-C showed larger critical micelle concentration (1.1x10(-5) M) than conventional MEL-C which bound C(10) and C(12) acids (9.1x10(-6) M). From these results, shorter fatty acids would confer hydrophilicity onto the novel MEL-C.

  3. Paleomagnetic study of antarctic deep-sea cores.

    PubMed

    Opdyke, N D; Glass, B; Hays, J D; Foster, J

    1966-10-21

    detritus, approximately 2.5 million years ago. One can also calculate rates of sedi mentation, which vary in the cores studied from 1.1 to about 8.0 millimeters per 1000 years. Sedimentation rates for the Indian Ocean cores are higher than for the Bellingshausen Sea cores. The near coincidence of faunal changes and reversals in the cores suggests but does not prove a causal relation. We conclude from this study that paleomagnetic stratigraphy is a unique method for correlating and dating deep sea cores, and that future work with such cores may provide a complete or nearly complete record of the history of the earth's magnetic field beyond 4 million years.

  4. The first records of deep-sea fauna - a correction and discussion

    NASA Astrophysics Data System (ADS)

    Etter, W.; Hess, H.

    2015-06-01

    The soundings in deep waters of Baffin Bay, together with the recovery of a basket star by John Ross in 1818, was a milestone in the history of deep-sea research. Although the alleged water depths of up to 1950 m were by far not reached, these were nevertheless the first soundings in deep bathyal (to perhaps uppermost abyssal) depths. Furthermore, the recovery of a benthic animal proved that animal life existed at great depths. Yet this was not the first published record of deep-sea fauna as it is often portrayed. This merit goes to accidental catches of the stalked crinoid Cenocrinus asterius that were recovered with fishing lines from upper bathyal environments near Antillean islands. In addition, the description of several deep-sea fishes considerably predated the John Ross episode.

  5. Reviews and syntheses: the first records of deep-sea fauna - a correction and discussion

    NASA Astrophysics Data System (ADS)

    Etter, W.; Hess, H.

    2015-11-01

    The soundings in deep waters of Baffin Bay, together with the recovery of a basket star by John Ross in 1818, was a milestone in the history of deep-sea research. Although the alleged water depths of up to 1950 m were by far not reached, these were nevertheless the first soundings in deep bathyal (to perhaps uppermost abyssal) depths. Furthermore, the recovery of a benthic animal proved that animal life existed at great depths. Yet this was not the first published record of deep-sea fauna as it is often portrayed. This merit goes to accidental catches of the stalked crinoid Cenocrinus asterius that were recovered with fishing lines from upper bathyal environments near Antillean islands. In addition, the description of several deep-sea fishes considerably predated the John Ross episode.

  6. Genomic and population genetic analysis of deep-sea vent chemoautotrophs

    NASA Astrophysics Data System (ADS)

    Nakagawa, S.; Shimamura, S.; Takaki, Y.; Mino, S.; Makita, H.; Sawabe, T.; Takai, K.

    2012-12-01

    Deep-sea vents are the light-independent, highly productive ecosystems driven primarily by chemoautotrophs. Most of the invertebrates thrive there through their relationship with symbiotic chemoautotrophs. Chemoautotrophs are microorganisms that are able to fix inorganic carbon using a chemical energy obtained through the oxidation of reduced compounds. Following the discovery of deep-sea vent ecosystems in 1977, there has been an increasing knowledge that deep-sea vent chemoautotrophs display remarkable physiological and phylogenetic diversity. Recent microbiological studies have led to an emerging view that the majority of deep-sea vent chemoautotrophs have the ability to derive energy from multiple redox couples other than the conventional sulfur-oxygen couple. Genomic, metagenomic and postgenomic studies have considerably accelerated the comprehensive understanding of molecular mechanisms of deep-sea vent chemoautotrophy, even in unculturable endosymbionts of vent fauna. For example, genomic analysis suggested that there were previously unrecognized evolutionary links between deep-sea vent chemoautotrophs and important human/animal pathogens. However, relatively little is known about the genome of horizontally transmitted endosymbionts. In this study, we sequenced whole genomes of the probably horizontally transmitted endosymbionts of two different gastropod species from a deep-sea hydrothermal field, as an effort to address questions about 1) the genome evolution of horizontally transmitted, facultative endosymbionts, 2) their genomic variability, and 3) genetic differences among symbionts of various deep-sea vent invertebrates. Both endosymbiont genomes display features consistent with ongoing genome reduction such as large proportions of pseudogenes and transposable elements. The genomes encode multiple functions for chemoautotrophic respirations, probably reflecting their adaptation to their niches with continuous changes in environmental conditions. When

  7. Selective erosion by gravity flows in the deep-sea Lofoten Basin, Norwegian Sea

    NASA Astrophysics Data System (ADS)

    Sverre Laberg, Jan; Forwick, Matthias; Johannessen, Hilde B.; Ivanov, Mikhail; Kenyon, Neil H.; Vorren, Tore O.

    2010-05-01

    Deposits from gravity flows form a substantial part of the Lofoten Basin stratigraphy, a deep-water basin offshore Norway. This includes glacigenic debris flows from the shelf edge/upper slope, sandy turbidites from canyon - channel systems and debris flow deposits from submarine landslides. Little is, however, known about the properties of the gravity flows and their interaction with the sea floor sediments. We present newly acquired deep-towed side-scan sonar data co-registered with sub-bottom profiles showing small and large-scale irregularities of the sea floor in two areas relatively recently affected by gravity flows. The first area is located at about 2700 m water depth and is part of the distal Andøya Slide. Here, three several km wide and about 25 m thick lensoid and acoustically transparent deposits with a slightly irregular relief are inferred to represent debris flow deposits from submarine landslides originating from the nearby continental slope. The seafloor both below the debris flows and between and not affected by the debris flows is irregular due to closed seafloor depressions. They occur randomly and with a variety of forms up to 1 km across, 500 m wide and some meters deep. The second area is the Lofoten Basin Channel near its termination at about 3200 m water depth, beyond which laterally extensive sheets of normal graded sand interbedded with thinner mud layers occur. Sea floor depressions appear in several morphological forms on the channel flanks. The largest is more than 1 km long, up to 250 m wide, some meters deep has its longest axis parallel to the flow direction. It becomes less distinct in the down-flow direction. Other features in this area include densely spaced longitudinal features. In both areas the irregular sea floor morphology is inferred to be flute marks (or scours) formed by erosive gravity flows. Erosion of channel flanks by turbidity currents is well known from other studies but is not commonly described from the most

  8. Between land and sea: divergent data stewardship practices in deep-sea biosphere research

    NASA Astrophysics Data System (ADS)

    Cummings, R.; Darch, P.

    2013-12-01

    Data in deep-sea biosphere research often live a double life. While the original data generated on IODP expeditions are highly structured, professionally curated, and widely shared, the downstream data practices of deep-sea biosphere laboratories are far more localized and ad hoc. These divergent data practices make it difficult to track the provenance of datasets from the cruise ships to the laboratory or to integrate IODP data with laboratory data. An in-depth study of the divergent data practices in deep-sea biosphere research allows us to: - Better understand the social and technical forces that shape data stewardship throughout the data lifecycle; - Develop policy, infrastructure, and best practices to improve data stewardship in small labs; - Track provenance of datasets from IODP cruises to labs and publications; - Create linkages between laboratory findings, cruise data, and IODP samples. In this paper, we present findings from the first year of a case study of the Center for Dark Energy Biosphere Investigations (C-DEBI), an NSF Science and Technology Center that studies life beneath the seafloor. Our methods include observation in laboratories, interviews, document analysis, and participation in scientific meetings. Our research uncovers the data stewardship norms of geologists, biologists, chemists, and hydrologists conducting multi-disciplinary research. Our research team found that data stewardship on cruises is a clearly defined task performed by an IODP curator, while downstream it is a distributed task that develops in response to local need and to the extent necessary for the immediate research team. IODP data are expensive to collect and challenging to obtain, often costing $50,000/day and requiring researchers to work twelve hours a day onboard the ships. To maximize this research investment, a highly trained IODP data curator controls data stewardship on the cruise and applies best practices such as standardized formats, proper labeling, and

  9. Nitratireductor indicus sp. nov., isolated from deep-sea water.

    PubMed

    Lai, Qiliang; Yu, Zhiwei; Yuan, Jun; Sun, Fengqin; Shao, Zongze

    2011-02-01

    A taxonomic study was carried out on a novel bacterial strain, designated C115(T), isolated from a crude-oil-degrading consortium, enriched from deep-sea water of the Indian Ocean. Cells were Gram-negative short rods, mobile by means of a monopolar flagellum. Growth was observed at salinities of 0-7 % and at 10-43 °C. It was unable to degrade Tween 80 or gelatin. 16S rRNA gene sequence analysis showed that strain C115(T) was related most closely to Nitratireductor aquibiodomus NL21(T) (96.5 % similarity), Nitratireductor kimnyeongensis KY 101(T) (96.4 %) and Nitratireductor basaltis J3(T) (96.2 %). The predominant fatty acids were summed feature 8 (C(18 : 1)ω7c and/or C(18 : 1)ω6c, 81.8 %) and C(18 : 0) (7.0 %). The G+C content of the chromosomal DNA of strain C115(T) was 59 mol%. Based on its morphology, physiology and fatty acid composition together with 16S rRNA gene sequence comparisons, the novel strain most appropriately belongs to the genus Nitratireductor, but can be distinguished readily from recognized species of the genus. Strain C115(T) is therefore considered to represent a novel species of the genus Nitratireductor, for which the name Nitratireductor indicus sp. nov. is proposed. The type strain is C115(T) (=RC92-7(T) =CCTCC AB 209298(T) =LMG 25540(T) =MCCC 1A01260(T)).

  10. Parvibaculum indicum sp. nov., isolated from deep-sea water.

    PubMed

    Lai, Qiliang; Wang, Liping; Liu, Yuhui; Yuan, Jun; Sun, Fengqin; Shao, Zongze

    2011-02-01

    A taxonomic study was carried out on strain P31(T), which was isolated from a polycyclic aromatic hydrocarbon (PAH)-degrading consortium enriched with deep-sea water of the Indian Ocean. The isolate was Gram-reaction-negative, rod-shaped, motile by means of a polar flagellum and incapable of reducing nitrate to nitrite. Growth was observed at 0.5-8 % NaCl and at 10-41 °C. Strain P31(T) was unable to degrade Tween 80 or gelatin. The major respiratory quinone was ubiquinone 11 (Q-11). The dominant fatty acids were C(18 : 1)ω7c (39.79 %), 11-methyl C(18 : 1)ω7c (17.84 %), C(19 : 0) cyclo ω8c (12.05 %) and C(18 : 0) (6.09 %). The G+C content of the chromosomal DNA was 62.1 mol%. A phylogenetic tree based on 16S rRNA gene sequence analysis showed that strain P31(T) and Parvibaculum lavamentivorans DS-1(T) formed a distinct lineage in the family Phyllobacteriaceae; these two strains showed 95.7 % sequence similarity, while similarities between P31(T) and other members of the genus Parvibaculum were below 93 %. Based on the genotypic and phenotypic data, strain P31(T) represents a novel species of the genus Parvibaculum, for which the name Parvibaculum indicum sp. nov. is proposed. The type strain is P31(T) (=CCTCC AB 208230(T) =LMG 24712(T) =MCCC 1A01132(T)).

  11. Citreicella marina sp. nov., isolated from deep-sea sediment.

    PubMed

    Lai, Qiliang; Fu, Yuanyuan; Wang, Jianning; Chen, Shuangxi; Zhong, Huanzi; Sun, Fengqin; Shao, Zongze

    2011-04-01

    A taxonomic study was carried out on a novel strain, designated CK-I3-6(T), which was isolated from deep-sea sediment of the south-west Indian Ocean Ridge. Cells were Gram-reaction-negative, oxidase- and catalase-positive, rod-shaped and non-motile. Growth was observed at 4-38 °C and in 1-12 % (w/v) NaCl. Cells were able to degrade gelatin and oxidize thiosulfate but did not reduce nitrate. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CK-I3-6(T) belonged to the genus Citreicella with a sequence similarity of 97.3 % to Citreicella thiooxidans CHLG 1(T), while similarities with other taxa were <95.7 %. DNA-DNA hybridization showed that strain CK-I3-6(T) and C. thiooxidans CHLG 1(T) showed a low DNA-DNA relatedness (48±3 %). The principal fatty acids were C(16 : 0) (7.8 %), C(18 : 1)ω7c (66.6 %), summed feature 3 (C(16 : 1)ω6c and/or C(16 : 1)ω7c; 6.3 %) and C(19 : 0)ω8c cyclo (10.0 %). The chromosomal DNA G+C content was 67.5 mol%. On the basis of the combined genotypic and phenotypic data, strain CK-I3-6(T) represents a novel species of the genus Citreicella, for which the name Citreicella marina sp. nov. is proposed. The type strain is CK-I3-6(T) ( = CCTCC AB 209064(T)  = LMG 25230(T)  = MCCC 1A03060(T)).

  12. Evidence for Permo-Triassic colonization of the deep sea by isopods.

    PubMed

    Lins, Luana S F; Ho, Simon Y W; Wilson, George D F; Lo, Nathan

    2012-12-23

    The deep sea is one of the largest ecosystems on Earth and is home to a highly diverse fauna, with polychaetes, molluscs and peracarid crustaceans as dominant groups. A number of studies have proposed that this fauna did not survive the anoxic events that occurred during the Mesozoic Era. Accordingly, the modern fauna is thought to be relatively young, perhaps having colonized the deep sea after the Eocene/Oligocene boundary. To test this hypothesis, we performed phylogenetic analyses of nuclear ribosomal 18S and 28S and mitochondrial cytochrome oxidase I and 16S sequences from isopod crustaceans. Using a molecular clock calibrated with multiple isopod fossils, we estimated the timing of deep-sea colonization events by isopods. Our results show that some groups have an ancient origin in the deep sea, with the earliest estimated dates spanning 232-314 Myr ago. Therefore, anoxic events at the Permian-Triassic boundary and during the Mesozoic did not cause the extinction of all the deep-sea fauna; some species may have gone extinct while others survived and proliferated. The monophyly of the 'munnopsid radiation' within the isopods suggests that the ancestors of this group evolved in the deep sea and did not move to shallow-water refugia during anoxic events.

  13. Trophic dynamics of deep-sea megabenthos are mediated by surface productivity.

    PubMed

    Tecchio, Samuele; van Oevelen, Dick; Soetaert, Karline; Navarro, Joan; Ramírez-Llodra, Eva

    2013-01-01

    Most deep-sea benthic ecosystems are food limited and, in the majority of cases, are driven by the organic matter falling from the surface or advected downslope. Species may adapt to this scarceness by applying a wide variety of responses, such as feeding specialisation, niche width variation, and reduction in metabolic rates. The Mediterranean Sea hosts a gradient of food availability at the deep seafloor over its wide longitudinal transect. In the Mediterranean, broad regional studies on trophic habits are almost absent, and the response of deep-sea benthos to different trophic conditions is still speculative. Here, we show that both primary and secondary production processes taking place at surface layers are key drivers of deep-sea food web structuring. By employing an innovative statistical tool, we interpreted bulk-tissue δ(13)C and δ(15)N isotope ratios in benthic megafauna, and associated surface and mesopelagic components from the 3 basins of the Mediterranean Sea at 3 different depths (1200, 2000, and 3000 m). The trophic niche width and the amplitude of primary carbon sources were positively correlated with both primary and secondary surface production indicators. Moreover, mesopelagic organic matter utilization processes showed an intermediate position between surface and deep benthic components. These results shed light on the understanding of deep-sea ecosystems functioning and, at the same time, they demand further investigation.

  14. Species-energy relationship in the deep sea: A test using the Quaternary fossil record

    USGS Publications Warehouse

    Hunt, G.; Cronin, T. M.; Roy, K.

    2005-01-01

    Little is known about the processes regulating species richness in deep-sea communities. Here we take advantage of natural experiments involving climate change to test whether predictions of the species-energy hypothesis hold in the deep sea. In addition, we test for the relationship between temperature and species richness predicted by a recent model based on biochemical kinetics of metabolism. Using the deep-sea fossil record of benthic foraminifera and statistical meta-analyses of temperature-richness and productivity-richness relationships in 10 deep-sea cores, we show that temperature but not productivity is a significant predictor of species richness over the past c. 130 000 years. Our results not only show that the temperature-richness relationship in the deep-sea is remarkably similar to that found in terrestrial and shallow marine habitats, but also that species richness tracks temperature change over geological time, at least on scales of c. 100 000 years. Thus, predicting biotic response to global climate change in the deep sea would require better understanding of how temperature regulates the occurrences and geographical ranges of species. ??2005 Blackwell Publishing Ltd/CNRS.

  15. Virus decomposition provides an important contribution to benthic deep-sea ecosystem functioning.

    PubMed

    Dell'Anno, Antonio; Corinaldesi, Cinzia; Danovaro, Roberto

    2015-04-21

    Viruses are key biological agents of prokaryotic mortality in the world oceans, particularly in deep-sea ecosystems where nearly all of the prokaryotic C production is transformed into organic detritus. However, the extent to which the decomposition of viral particles (i.e., organic material of viral origin) influences the functioning of benthic deep-sea ecosystems remains completely unknown. Here, using various independent approaches, we show that in deep-sea sediments an important fraction of viruses, once they are released by cell lysis, undergo fast decomposition. Virus decomposition rates in deep-sea sediments are high even at abyssal depths and are controlled primarily by the extracellular enzymatic activities that hydrolyze the proteins of the viral capsids. We estimate that on a global scale the decomposition of benthic viruses releases ∼37-50 megatons of C per year and thus represents an important source of labile organic compounds in deep-sea ecosystems. Organic material released from decomposed viruses is equivalent to 3 ± 1%, 6 ± 2%, and 12 ± 3% of the input of photosynthetically produced C, N, and P supplied through particles sinking to bathyal/abyssal sediments. Our data indicate that the decomposition of viruses provides an important, previously ignored contribution to deep-sea ecosystem functioning and has an important role in nutrient cycling within the largest ecosystem of the biosphere.

  16. Deep-sea hydrothermal vents: potential hot spots for natural products discovery?

    PubMed

    Thornburg, Christopher C; Zabriskie, T Mark; McPhail, Kerry L

    2010-03-26

    Deep-sea hydrothermal vents are among the most extreme and dynamic environments on Earth. However, islands of highly dense and biologically diverse communities exist in the immediate vicinity of hydrothermal vent flows, in stark contrast to the surrounding bare seafloor. These communities comprise organisms with distinct metabolisms based on chemosynthesis and growth rates comparable to those from shallow water tropical environments, which have been rich sources of biologically active natural products. The geological setting and geochemical nature of deep-sea vents that impact the biogeography of vent organisms, chemosynthesis, and the known biological and metabolic diversity of Eukarya, Bacteria, and Archaea, including the handful of natural products isolated to date from deep-sea vent organisms, are considered here in an assessment of deep-sea hydrothermal vents as potential hot spots for natural products investigations. Of critical importance too are the logistics of collecting deep vent organisms, opportunities for re-collection considering the stability and longevity of vent sites, and the ability to culture natural product-producing deep vent organisms in the laboratory. New cost-effective technologies in deep-sea research and more advanced molecular techniques aimed at screening a more inclusive genetic assembly are poised to accelerate natural product discoveries from these microbial diversity hot spots.

  17. Polychlorinated biphenyl and organochlorine pesticide contamination signatures in deep-sea fish from the Mediterranean Sea.

    PubMed

    Storelli, M M; Losada, S; Marcotrigiano, G O; Roosens, L; Barone, G; Neels, H; Covaci, A

    2009-10-01

    Polychlorinated biphenyl (PCB) and OCP concentrations were determined in the livers of two deep-sea fish species, roughsnout grenadier and hollowsnout grenadier, from the Adriatic Sea. In both species, contaminant concentrations were in the following order: PCBs>DDTs>HCB. Contaminant load was higher in roughsnout grenadier (PCB: 12,327ngg(-1); DDTs: 5357ngg(-1); HCB: 13.1ngg(-1)) than in hollowsnout grenadier (PCB: 1234ngg(-1); DDTs: 763ngg(-1); HCB 6.3ngg(-1)). PCB patterns were dominated by higher chlorinated congeners (hexa-CBs: 50.3-52.1%, hepta-CBs: 29.6-35.5%, penta-CBs: 8.0-11.1% and octa-CBs :5.2-5.4%). PCBs 138, 153 180 and 187 were the most abundant. Regarding the DDT pattern, p,p'-DDE was prevalent in both species (roughsnout grenadier: 99.7%, hollowsnout grenadier: 90%), suggesting no recent DDT input. In both species, the total 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalent (TEQ) concentrations (roughsnout grenadier: mean 43.77pg/g, hollowsnout grenadier: mean 20.49pg/g), calculated from non- and mono-ortho PCBs, reached those encountered in marine organisms at higher levels in the trophic chain.

  18. On the origin of multiple BSRs in the Danube deep-sea fan, Black Sea

    NASA Astrophysics Data System (ADS)

    Zander, Timo; Haeckel, Matthias; Berndt, Christian; Chi, Wu-Cheng; Klaucke, Ingo; Bialas, Joerg; Klaeschen, Dirk; Koch, Stephanie; Atgın, Orhan

    2017-03-01

    High-resolution 2D seismic data reveal the character and distribution of up to four stacked bottom simulating reflectors (BSR) within the channel-levee systems of the Danube deep-sea fan. The theoretical base of the gas hydrate stability zone (GHSZ) calculated from regional geothermal gradients and salinity data is in agreement with the shallowest BSR. For the deeper BSRs, BSR formation due to overpressure compartments can be excluded because the necessary gas column would exceed the vertical distance between two overlying BSRs. We show instead that the deeper BSRs are likely paleo BSRs caused by a change in pressure and temperature conditions during different limnic phases of the Black Sea. This is supported by the observation that the BSRs correspond to paleo seafloor horizons located in a layer between a buried channel-levee system and the levee deposits of the Danube channel. The good match of the observed BSRs and the BSRs predicted from deposition of these sediment layers indicates that the multiple BSRs reflect stages of stable sealevel lowstands possibly during glacial times. The observation of sharp BSRs several 10,000 of years but possibly up to 300,000 yr after they have left the GHSZ demonstrates that either hydrate dissociation does not take place within this time frame or that only small amounts of gas are released that can be transported by diffusion. The gas underneath the previous GHSZ does not start to migrate for several thousands of years.

  19. Heterogeneity and lithotype distribution in ancient deep-sea canyons: Point Lobos deep-sea canyon as a reservoir analogue

    NASA Astrophysics Data System (ADS)

    Cronin, Bryan T.; Kidd, Robert B.

    1998-01-01

    An evolution and history of filling is proposed for an exceptionally exposed ancient deep-sea canyon on a Paleocene oblique-slip tectonic margin which, on a number of scales, reveals, successive phases of canyon activity. The quantitative methods adopted for this study make it of direct use to modellers as an example of reservoir heterogeneity in an ancient canyon fill, where facies distribution from boreholes can be scaled up to reconstruct the reservoir, using the methods outlined in this paper. The Point Lobos submarine canyon, near Carmel in California, provides a complete cross-section of an ancient canyon, with a fill which displays a whole range of channel morphologies, and laterally extensive coverage of the internal architecture of associated conglomerate packages and related debris flows. This paper presents quantitative documentation of the canyon-fill sediments and canyon-wide fill packages, on scales which vary from bed-to-bed analysis, reflecting processes in operation during individual events, to canyon-wide analysis, reflecting the overall evolution of the canyon. The northern and southern canyon margins are both exposed, and the Paleocene fill onlaps the subvertical canyon wall. The canyon was incised into Cretaceous granodiorite. The fill comprises five thick sequences which correspond to five successive phases of sediment deposition within the canyon. Each sequence typically consists of resedimented conglomerates that are stacked and channelised, with a vertical architecture which resembles that of subaerial braided stream deposits. These are overlain by channelised turbidite sandstones, interbedded with intraformational conglomerates and mud-chip breccias. These in turn are overlain by mudstones and shales, which are commonly slumped and disturbed. Published classification schemes that show the range of deep-water facies were found insufficient to describe the Point Lobos canyon fill. Methods were developed for recording the lithologic

  20. A Dataset of Deep-Sea Fishes Surveyed by Research Vessels in the Waters around Taiwan.

    PubMed

    Shao, Kwang-Tsao; Lin, Jack; Yeh, Hsin-Ming; Lee, Mao-Yin; Chen, Lee-Sea; Lin, Hen-Wei

    2014-01-01

    The study of deep-sea fish fauna is hampered by a lack of data due to the difficulty and high cost incurred in its surveys and collections. Taiwan is situated along the edge of the Eurasia fig, at the junction of three Large Marine Ecosystems or Ecoregions of the East China Sea, South China Sea and the Philippines. As nearly two-thirds of its surrounding marine ecosystems are deep-sea environments, Taiwan is expected to hold a rich diversity of deep-sea fish. However, in the past, no research vessels were employed to collect fish data on site. Only specimens, caught by bottom trawl fishing in the waters hundreds of meters deep and missing precise locality information, were collected from Dasi and Donggang fishing harbors. Began in 2001, with the support of National Science Council, research vessels were made available to take on the task of systematically collecting deep-sea fish specimens and occurrence records in the waters surrounding Taiwan. By the end of 2006, a total of 3,653 specimens, belonging to 26 orders, 88 families, 198 genera and 366 species, were collected in addition to data such as sampling site geographical coordinates and water depth, and fish body length and weight. The information, all accessible from the "Database of Taiwan's Deep-Sea Fauna and Its Distribution (http://deepsea.biodiv.tw/)" as part of the "Fish Database of Taiwan," can benefit the study of temporal and spatial changes in distribution and abundance of fish fauna in the context of global deep-sea biodiversity.

  1. A Dataset of Deep-Sea Fishes Surveyed by Research Vessels in the Waters around Taiwan

    PubMed Central

    Shao, Kwang-Tsao; Lin, Jack; Yeh, Hsin-Ming; Lee, Mao-Yin; Chen, Lee-Sea; Lin, Hen-Wei

    2014-01-01

    Abstract The study of deep-sea fish fauna is hampered by a lack of data due to the difficulty and high cost incurred in its surveys and collections. Taiwan is situated along the edge of the Eurasia fig, at the junction of three Large Marine Ecosystems or Ecoregions of the East China Sea, South China Sea and the Philippines. As nearly two-thirds of its surrounding marine ecosystems are deep-sea environments, Taiwan is expected to hold a rich diversity of deep-sea fish. However, in the past, no research vessels were employed to collect fish data on site. Only specimens, caught by bottom trawl fishing in the waters hundreds of meters deep and missing precise locality information, were collected from Dasi and Donggang fishing harbors. Began in 2001, with the support of National Science Council, research vessels were made available to take on the task of systematically collecting deep-sea fish specimens and occurrence records in the waters surrounding Taiwan. By the end of 2006, a total of 3,653 specimens, belonging to 26 orders, 88 families, 198 genera and 366 species, were collected in addition to data such as sampling site geographical coordinates and water depth, and fish body length and weight. The information, all accessible from the “Database of Taiwan’s Deep-Sea Fauna and Its Distribution (http://deepsea.biodiv.tw/)” as part of the “Fish Database of Taiwan,” can benefit the study of temporal and spatial changes in distribution and abundance of fish fauna in the context of global deep-sea biodiversity. PMID:25610339

  2. Man and the Last Great Wilderness: Human Impact on the Deep Sea

    PubMed Central

    Ramirez-Llodra, Eva; Tyler, Paul A.; Baker, Maria C.; Bergstad, Odd Aksel; Clark, Malcolm R.; Escobar, Elva; Levin, Lisa A.; Menot, Lenaick; Rowden, Ashley A.; Smith, Craig R.; Van Dover, Cindy L.

    2011-01-01

    The deep sea, the largest ecosystem on Earth and one of the least studied, harbours high biodiversity and provides a wealth of resources. Although humans have used the oceans for millennia, technological developments now allow exploitation of fisheries resources, hydrocarbons and minerals below 2000 m depth. The remoteness of the deep seafloor has promoted the disposal of residues and litter. Ocean acidification and climate change now bring a new dimension of global effects. Thus the challenges facing the deep sea are large and accelerating, providing a new imperative for the science community, industry and national and international organizations to work together to develop successful exploitation management and conservation of the deep-sea ecosystem. This paper provides scientific expert judgement and a semi-quantitative analysis of past, present and future impacts of human-related activities on global deep-sea habitats within three categories: disposal, exploitation and climate change. The analysis is the result of a Census of Marine Life – SYNDEEP workshop (September 2008). A detailed review of known impacts and their effects is provided. The analysis shows how, in recent decades, the most significant anthropogenic activities that affect the deep sea have evolved from mainly disposal (past) to exploitation (present). We predict that from now and into the future, increases in atmospheric CO2 and facets and consequences of climate change will have the most impact on deep-sea habitats and their fauna. Synergies between different anthropogenic pressures and associated effects are discussed, indicating that most synergies are related to increased atmospheric CO2 and climate change effects. We identify deep-sea ecosystems we believe are at higher risk from human impacts in the near future: benthic communities on sedimentary upper slopes, cold-water corals, canyon benthic communities and seamount pelagic and benthic communities. We finalise this review with a short

  3. Man and the last great wilderness: human impact on the deep sea.

    PubMed

    Ramirez-Llodra, Eva; Tyler, Paul A; Baker, Maria C; Bergstad, Odd Aksel; Clark, Malcolm R; Escobar, Elva; Levin, Lisa A; Menot, Lenaick; Rowden, Ashley A; Smith, Craig R; Van Dover, Cindy L

    2011-01-01

    The deep sea, the largest ecosystem on Earth and one of the least studied, harbours high biodiversity and provides a wealth of resources. Although humans have used the oceans for millennia, technological developments now allow exploitation of fisheries resources, hydrocarbons and minerals below 2000 m depth. The remoteness of the deep seafloor has promoted the disposal of residues and litter. Ocean acidification and climate change now bring a new dimension of global effects. Thus the challenges facing the deep sea are large and accelerating, providing a new imperative for the science community, industry and national and international organizations to work together to develop successful exploitation management and conservation of the deep-sea ecosystem. This paper provides scientific expert judgement and a semi-quantitative analysis of past, present and future impacts of human-related activities on global deep-sea habitats within three categories: disposal, exploitation and climate change. The analysis is the result of a Census of Marine Life--SYNDEEP workshop (September 2008). A detailed review of known impacts and their effects is provided. The analysis shows how, in recent decades, the most significant anthropogenic activities that affect the deep sea have evolved from mainly disposal (past) to exploitation (present). We predict that from now and into the future, increases in atmospheric CO(2) and facets and consequences of climate change will have the most impact on deep-sea habitats and their fauna. Synergies between different anthropogenic pressures and associated effects are discussed, indicating that most synergies are related to increased atmospheric CO(2) and climate change effects. We identify deep-sea ecosystems we believe are at higher risk from human impacts in the near future: benthic communities on sedimentary upper slopes, cold-water corals, canyon benthic communities and seamount pelagic and benthic communities. We finalise this review with a short

  4. North Pacific Acoustic Laboratory: Deep Water Acoustic Propagation in the Philippine Sea

    DTIC Science & Technology

    2016-06-21

    Acoustic Laboratory: Deep Water Acoustic Propagation in the Philippine Sea 5b. GRANT NUMBER NOOO 14-12-1 -0226 5c. PROGRAM ELEMENT NUMBER 6...the "Special Issue on Deep- water Ocean Acoustics" in the Journal of the Acoustical Society of America (Vol. 134, No . 4, Pt. 2 of 2 , October20 13...15. SUBJECT TERMS ocean acoustics, deep water acousti c propagati on 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF a. REPORT b. ABSTRACT c

  5. Bathyal sea urchins of the Bahamas, with notes on covering behavior in deep sea echinoids (Echinodermata: Echinoidea)

    NASA Astrophysics Data System (ADS)

    Pawson, David L.; Pawson, Doris J.

    2013-08-01

    In a survey of the bathyal echinoderms of the Bahama Islands region using manned submersibles, approximately 200 species of echinoderms were encountered and documented; 33 species were echinoids, most of them widespread in the general Caribbean area. Three species were found to exhibit covering behavior, the piling of debris on the upper surface of the body. Active covering is common in at least 20 species of shallow-water echinoids, but it has been reliably documented previously only once in deep-sea habitats. Images of covered deep-sea species, and other species of related interest, are provided. Some of the reasons adduced in the past for covering in shallow-water species, such as reduction of incident light intensity, physical camouflage, ballast in turbulent water, protection from desiccation, presumably do not apply in bathyal species. The main reasons for covering in deep, dark, environments are as yet unknown. Some covering behavior in the deep sea may be related to protection of the genital pores, ocular plates, or madreporite. Covering in some deep-sea species may also be merely a tactile reflex action, as some authors have suggested for shallow-water species.

  6. Ventilation of the deep Greenland and Norwegian seas: evidence from krypton-85, tritium, carbon-14 and argon-39

    NASA Astrophysics Data System (ADS)

    Smethie, W. M.; Ostlund, H. G.; Loosli, H. H.

    1986-05-01

    On leg 5 of the TTO expedition, the distributions of 85Kr, tritium, 14C, 39Ar, temperature, salinity, oxygen, carbon dioxide and nutrients were measured in the Greenland and Norwegian seas. These observations support previous observations that Greenland Sea Deep Water is formed by a deep convective process within the Greenland gyre. They also support AAGAARDet al.'s (1985, Journal of Geophysical Research, 90, 4833-4846) new hypothesis that Norwegian Sea Deep Water forms from a mixture of Greenland Sea Deep Water and Eurasian Basin Deep Water. Volume transports estimated from the distributions of 85Kr, tritium, 14C and 39Ar range from 0.53 to 0.74 Sv for exchange between the surface and deep Greenland Sea and from 0.9 to 1.47 Sv for exchange between the deep Greenland and deep Norwegian seas. The residence time of water in the deep Greenland Sea with respect to exchange with surface water ranges from 24 to 34 years compared to 26-31 years reported by PETERSON and ROOTH (1976, Deep-Sea Research, 23, 273-283) and 35-42 years reported by BULLISTER and WEISSS (1983, Science, 221, 265-268). The residence time of water in the deep Norwegian Sea with respect to exchange with the deep Greenland Sea ranges from 19 to 30 years compared to 97-107 years reported by PETERSON and ROOTH (1976) and 10-28 years reported by BULLISTER and WEISS (1983). The oxygen consumption rate was estimated to be at most 1.04 μM kg -1 y -1 for the deep Greenland Sea and to be between 0.47 and 0.79 μM kg -1 y -1 for the deep Norwegian Sea.

  7. Another bipolar deep-sea anemone: new species of Iosactis (Actiniaria, Endomyaria) from Antarctica

    NASA Astrophysics Data System (ADS)

    Rodríguez, Estefanía

    2012-06-01

    A new species of deep-sea burrowing sea anemone is described and illustrated from Antarctica. Iosactis antarctica sp. nov. is characterised by easily deciduous tentacles with sphincters in the base, smooth column, endodermal marginal sphincter, same mesenteries proximally and distally, 24 perfect mesenteries regularly arranged, diffuse retractor musculature and basilar muscles well developed. Iosactis antarctica sp. nov. is the second species of the deep-sea abyssal genus Iosactis; it differs from I. vagabunda in internal anatomy, cnidae and geographic distribution. The description of I. antarctica sp. nov. provides the opportunity to revaluate the morphology of the proximal end of this genus.

  8. Comparative multi-locus phylogeography confirms multiple vicariance events in co-distributed rainforest frogs

    PubMed Central

    Bell, Rayna C.; MacKenzie, Jason B.; Hickerson, Michael J.; Chavarría, Krystle L.; Cunningham, Michael; Williams, Stephen; Moritz, Craig

    2012-01-01

    Though Pleistocene refugia are frequently cited as drivers of species diversification, comparisons of molecular divergence among sister species typically indicate a continuum of divergence times from the Late Miocene, rather than a clear pulse of speciation events at the Last Glacial Maximum. Community-scale inference methods that explicitly test for multiple vicariance events, and account for differences in ancestral effective population size and gene flow, are well suited for detecting heterogeneity of species' responses to past climate fluctuations. We apply this approach to multi-locus sequence data from five co-distributed frog species endemic to the Wet Tropics rainforests of northeast Australia. Our results demonstrate at least two episodes of vicariance owing to climate-driven forest contractions: one in the Early Pleistocene and the other considerably older. Understanding how repeated cycles of rainforest contraction and expansion differentially affected lineage divergence among co-distributed species provides a framework for identifying evolutionary processes that underlie population divergence and speciation. PMID:21900325

  9. Multi-locus sequence type analysis of Shigellas pp. isolates from Tehran, Iran

    PubMed Central

    Shahsavan, Shadi; Nobakht, Maliheh; Rastegar-Lari, Abdolaziz; Owlia, Parviz; Bakhshi, Bita

    2016-01-01

    Background and Objectives: Strains of Shigella spp. can cause shigellosis, or bacillary dysentery. that is a public health problem worldwide. The aim of this study was to describe the population structure and genetic relatedness of multidrug resistant S. sonnei and S. flexneri isolated during a one year period from children with diarrhea in Tehran, Iran. Materials and Methods: A total of 70 Shigella spp. were detected during the study period. Twenty MDR isolates of Shigella spp. were randomly selected and used in this study. Bacterial identification was performed by conventional biochemical and serological and confirmed by molecular method. After antimicrobial susceptibility testing, we used Multilocus sequence typing (MLST) for subtyping isolates. Results: We found 14 Shigella sonnei and 6 Shigella flexneri isolates. Results of MLST showed five sequence types (ST) (145, 152, 241, 245, 1502) and BURST analysis revealed the largest number of single locus variant (SLV) and highest frequency (FREQ) for ST152. ST 152 with nine members was predicted as the founder by BURST. Frequency for ST 1502 and ST 245 was four isolates and the least frequency was seen for ST 241 and 145 with one and two members, respectively. ST 145 and ST 245 were described as singletons in BURST. All isolates with ST145 and ST245 were identified as Shigella flexneri. Conclusion: Annual Multi locus sequence typing of MDR Shigella would help us in better understanding of dominant species and comparing our results with the same studies in other countries especially our neighbor countries in source tracking purposes. PMID:28149488

  10. Multi-locus Analyses Reveal Four Giraffe Species Instead of One.

    PubMed

    Fennessy, Julian; Bidon, Tobias; Reuss, Friederike; Kumar, Vikas; Elkan, Paul; Nilsson, Maria A; Vamberger, Melita; Fritz, Uwe; Janke, Axel

    2016-09-26

    Traditionally, one giraffe species and up to eleven subspecies have been recognized [1]; however, nine subspecies are commonly accepted [2]. Even after a century of research, the distinctness of each giraffe subspecies remains unclear, and the genetic variation across their distribution range has been incompletely explored. Recent genetic studies on mtDNA have shown reciprocal monophyly of the matrilines among seven of the nine assumed subspecies [3, 4]. Moreover, until now, genetic analyses have not been applied to biparentally inherited sequence data and did not include data from all nine giraffe subspecies. We sampled natural giraffe populations from across their range in Africa, and for the first time individuals from the nominate subspecies, the Nubian giraffe, Giraffa camelopardalis camelopardalis Linnaeus 1758 [5], were included in a genetic analysis. Coalescence-based multi-locus and population genetic analyses identify at least four separate and monophyletic clades, which should be recognized as four distinct giraffe species under the genetic isolation criterion. Analyses of 190 individuals from maternal and biparental markers support these findings and further suggest subsuming Rothschild's giraffe into the Nubian giraffe, as well as Thornicroft's giraffe into the Masai giraffe [6]. A giraffe survey genome produced valuable data from microsatellites, mobile genetic elements, and accurate divergence time estimates. Our findings provide the most inclusive analysis of giraffe relationships to date and show that their genetic complexity has been underestimated, highlighting the need for greater conservation efforts for the world's tallest mammal.

  11. Identification of Coxiella burnetii genotypes in Croatia using multi-locus VNTR analysis.

    PubMed

    Račić, Ivana; Spičić, Silvio; Galov, Ana; Duvnjak, Sanja; Zdelar-Tuk, Maja; Vujnović, Anja; Habrun, Boris; Cvetnić, Zeljko

    2014-10-10

    Although Q fever affects humans and animals in Croatia, we are unaware of genotyping studies of Croatian strains of the causative pathogen Coxiella burnetii, which would greatly assist monitoring and control efforts. Here 3261 human and animal samples were screened for C. burnetii DNA by conventional PCR, and 335 (10.3%) were positive. Of these positive samples, 82 were genotyped at 17 loci using the relatively new method of multi-locus variable number tandem repeat analysis (MLVA). We identified 13 C. burnetii genotypes not previously reported anywhere in the world. Two of these 13 genotypes are typical of the continental part of Croatia and share more similarity with genotypes outside Croatia than with genotypes within the country. The remaining 11 novel genotypes are typical of the coastal part of Croatia and show more similarity to one another than to genotypes outside the country. Our findings shed new light on the phylogeny of C. burnetii strains and may help establish MLVA as a standard technique for Coxiella genotyping.

  12. Distinctive Microbial Community Structure in Highly Stratified Deep-Sea Brine Water Columns

    PubMed Central

    Bougouffa, S.; Yang, J. K.; Lee, O. O.; Wang, Y.; Batang, Z.; Al-Suwailem, A.

    2013-01-01

    Atlantis II and Discovery are two hydrothermal and hypersaline deep-sea pools in the Red Sea rift that are characterized by strong thermohalo-stratification and temperatures steadily peaking near the bottom. We conducted comprehensive vertical profiling of the microbial populations in both pools and highlighted the influential environmental factors. Pyrosequencing of the 16S rRNA genes revealed shifts in community structures vis-à-vis depth. High diversity and low abundance were features of the deepest convective layers despite the low cell density. Surprisingly, the brine interfaces had significantly higher cell counts than the overlying deep-sea water, yet they were lowest in diversity. Vertical stratification of the bacterial populations was apparent as we moved from the Alphaproteobacteria-dominated deep sea to the Planctomycetaceae- or Deferribacteres-dominated interfaces to the Gammaproteobacteria-dominated brine layers. Archaeal marine group I was dominant in the deep-sea water and interfaces, while several euryarchaeotic groups increased in the brine. Across sites, microbial phylotypes and abundances varied substantially in the brine interface of Discovery compared with Atlantis II, despite the near-identical populations in the overlying deep-sea waters. The lowest convective layers harbored interestingly similar microbial communities, even though temperature and heavy metal concentrations were very different. Multivariate analysis indicated that temperature and salinity were the major influences shaping the communities. The harsh conditions and the low-abundance phylotypes could explain the observed correlation in the brine pools. PMID:23542623

  13. Genetic diversity of archaea in deep-sea hydrothermal vent environments.

    PubMed

    Takai, K; Horikoshi, K

    1999-08-01

    Molecular phylogenetic analysis of naturally occurring archaeal communities in deep-sea hydrothermal vent environments was carried out by PCR-mediated small subunit rRNA gene (SSU rDNA) sequencing. As determined through partial sequencing of rDNA clones amplified with archaea-specific primers, the archaeal populations in deep-sea hydrothermal vent environments showed a great genetic diversity, and most members of these populations appeared to be uncultivated and unidentified organisms. In the phylogenetic analysis, a number of rDNA sequences obtained from deep-sea hydrothermal vents were placed in deep lineages of the crenarchaeotic phylum prior to the divergence of cultivated thermophilic members of the crenarchaeota or between thermophilic members of the euryarchaeota and members of the methanogen-halophile clade. Whole cell in situ hybridization analysis suggested that some microorganisms of novel phylotypes predicted by molecular phylogenetic analysis were likely present in deep-sea hydrothermal vent environments. These findings expand our view of the genetic diversity of archaea in deep-sea hydrothermal vent environments and of the phylogenetic organization of archaea.

  14. Impacts on the deep-sea ecosystem by a severe coastal storm.

    PubMed

    Sanchez-Vidal, Anna; Canals, Miquel; Calafat, Antoni M; Lastras, Galderic; Pedrosa-Pàmies, Rut; Menéndez, Melisa; Medina, Raúl; Company, Joan B; Hereu, Bernat; Romero, Javier; Alcoverro, Teresa

    2012-01-01

    Major coastal storms, associated with strong winds, high waves and intensified currents, and occasionally with heavy rains and flash floods, are mostly known because of the serious damage they can cause along the shoreline and the threats they pose to navigation. However, there is a profound lack of knowledge on the deep-sea impacts of severe coastal storms. Concurrent measurements of key parameters along the coast and in the deep-sea are extremely rare. Here we present a unique data set showing how one of the most extreme coastal storms of the last decades lashing the Western Mediterranean Sea rapidly impacted the deep-sea ecosystem. The storm peaked the 26(th) of December 2008 leading to the remobilization of a shallow-water reservoir of marine organic carbon associated with fine particles and resulting in its redistribution across the deep basin. The storm also initiated the movement of large amounts of coarse shelf sediment, which abraded and buried benthic communities. Our findings demonstrate, first, that severe coastal storms are highly efficient in transporting organic carbon from shallow water to deep water, thus contributing to its sequestration and, second, that natural, intermittent atmospheric drivers sensitive to global climate change have the potential to tremendously impact the largest and least known ecosystem on Earth, the deep-sea ecosystem.

  15. Impacts on the Deep-Sea Ecosystem by a Severe Coastal Storm

    PubMed Central

    Sanchez-Vidal, Anna; Canals, Miquel; Calafat, Antoni M.; Lastras, Galderic; Pedrosa-Pàmies, Rut; Menéndez, Melisa; Medina, Raúl; Company, Joan B.; Hereu, Bernat; Romero, Javier; Alcoverro, Teresa

    2012-01-01

    Major coastal storms, associated with strong winds, high waves and intensified currents, and occasionally with heavy rains and flash floods, are mostly known because of the serious damage they can cause along the shoreline and the threats they pose to navigation. However, there is a profound lack of knowledge on the deep-sea impacts of severe coastal storms. Concurrent measurements of key parameters along the coast and in the deep-sea are extremely rare. Here we present a unique data set showing how one of the most extreme coastal storms of the last decades lashing the Western Mediterranean Sea rapidly impacted the deep-sea ecosystem. The storm peaked the 26th of December 2008 leading to the remobilization of a shallow-water reservoir of marine organic carbon associated with fine particles and resulting in its redistribution across the deep basin. The storm also initiated the movement of large amounts of coarse shelf sediment, which abraded and buried benthic communities. Our findings demonstrate, first, that severe coastal storms are highly efficient in transporting organic carbon from shallow water to deep water, thus contributing to its sequestration and, second, that natural, intermittent atmospheric drivers sensitive to global climate change have the potential to tremendously impact the largest and least known ecosystem on Earth, the deep-sea ecosystem. PMID:22295084

  16. Global pulses of organic carbon burial in deep-sea sediments during glacial maxima

    PubMed Central

    Cartapanis, Olivier; Bianchi, Daniele; Jaccard, Samuel L.; Galbraith, Eric D.

    2016-01-01

    The burial of organic carbon in marine sediments removes carbon dioxide from the ocean–atmosphere pool, provides energy to the deep biosphere, and on geological timescales drives the oxygenation of the atmosphere. Here we quantify natural variations in the burial of organic carbon in deep-sea sediments over the last glacial cycle. Using a new data compilation of hundreds of sediment cores, we show that the accumulation rate of organic carbon in the deep sea was consistently higher (50%) during glacial maxima than during interglacials. The spatial pattern and temporal progression of the changes suggest that enhanced nutrient supply to parts of the surface ocean contributed to the glacial burial pulses, with likely additional contributions from more efficient transfer of organic matter to the deep sea and better preservation of organic matter due to reduced oxygen exposure. These results demonstrate a pronounced climate sensitivity for this global carbon cycle sink. PMID:26923945

  17. Spatial distribution of marine crenarchaeota group I in the vicinity of deep-sea hydrothermal systems.

    PubMed

    Takai, Ken; Oida, Hanako; Suzuki, Yohey; Hirayama, Hisako; Nakagawa, Satoshi; Nunoura, Takuro; Inagaki, Fumio; Nealson, Kenneth H; Horikoshi, Koki

    2004-04-01

    Distribution profiles of marine crenarchaeota group I in the vicinity of deep-sea hydrothermal systems were mapped with culture-independent molecular techniques. Planktonic samples were obtained from the waters surrounding two geographically and geologically distinct hydrothermal systems, and the abundance of marine crenarchaeota group I was examined by 16S ribosomal DNA clone analysis, quantitative PCR, and whole-cell fluorescence in situ hybridization. A much higher proportion of marine crenarchaeota group I within the microbial community was detected in deep-sea hydrothermal environments than in normal deep and surface seawaters. The highest proportion was always obtained from the ambient seawater adjacent to hydrothermal emissions and chimneys but not from the hydrothermal plumes. These profiles were markedly different from the profiles of epsilon-Proteobacteria, which are abundant in the low temperatures of deep-sea hydrothermal environments.

  18. Irminger Sea deep convection injects oxygen and anthropogenic carbon to the ocean interior

    PubMed Central

    Fröb, F.; Olsen, A.; Våge, K.; Moore, G. W. K.; Yashayaev, I.; Jeansson, E.; Rajasakaren, B.

    2016-01-01

    Deep convection in the subpolar North Atlantic ventilates the ocean for atmospheric gases through the formation of deep water masses. Variability in the intensity of deep convection is believed to have caused large variations in North Atlantic anthropogenic carbon storage over the past decades, but observations of the properties during active convection are missing. Here we document the origin, extent and chemical properties of the deepest winter mixed layers directly observed in the Irminger Sea. As a result of the deep convection in winter 2014–2015, driven by large oceanic heat loss, mid-depth oxygen concentrations were replenished and anthropogenic carbon storage rates almost tripled compared with Irminger Sea hydrographic section data in 1997 and 2003. Our observations provide unequivocal evidence that ocean ventilation and anthropogenic carbon uptake take place in the Irminger Sea and that their efficiency can be directly linked to atmospheric forcing. PMID:27786263

  19. Irminger Sea deep convection injects oxygen and anthropogenic carbon to the ocean interior

    NASA Astrophysics Data System (ADS)

    Fröb, F.; Olsen, A.; Våge, K.; Moore, G. W. K.; Yashayaev, I.; Jeansson, E.; Rajasakaren, B.

    2016-10-01

    Deep convection in the subpolar North Atlantic ventilates the ocean for atmospheric gases through the formation of deep water masses. Variability in the intensity of deep convection is believed to have caused large variations in North Atlantic anthropogenic carbon storage over the past decades, but observations of the properties during active convection are missing. Here we document the origin, extent and chemical properties of the deepest winter mixed layers directly observed in the Irminger Sea. As a result of the deep convection in winter 2014-2015, driven by large oceanic heat loss, mid-depth oxygen concentrations were replenished and anthropogenic carbon storage rates almost tripled compared with Irminger Sea hydrographic section data in 1997 and 2003. Our observations provide unequivocal evidence that ocean ventilation and anthropogenic carbon uptake take place in the Irminger Sea and that their efficiency can be directly linked to atmospheric forcing.

  20. Hydrothermal mixing: Fuel for life in the deep-sea

    NASA Astrophysics Data System (ADS)

    Hentscher, M.; Bach, W.; Amend, J.; McCollom, T.

    2009-04-01

    Deep-sea hydrothermal vent systems show a wide range of fluid compositions and temperatures. They reach from highly alkaline and reducing, like the Lost City hydrothermal field, to acidic and reducing conditions, (e. g., the Logatchev hydrothermal field) to acidic and oxidizing conditions (e. g., island arc hosted systems). These apparently hostile vent systems are generally accompanied by high microbial activity forming the base of a food-web that often includes higher organisms like mussels, snails, or shrimp. The primary production is boosted by mixing of chemically reduced hydrothermal vent fluids with ambient seawater, which generates redox disequilibria that serve as energy source for chemolithoautotrophic microbial life. We used geochemical reaction path models to compute the affinities of catabolic (energy-harvesting) and anabolic (biosynthesis) reactions along trajectories of batch mixing between vent fluids and 2 °C seawater. Geochemical data of endmember hydrothermal fluids from 12 different vent fields (Lost City, Rainbow, Logatchev, TAG, EPR 21 °N, Manus Basin, Mariana Arc, etc.) were included in this reconnaissance study of the variability in metabolic energetics in global submarine vent systems. The results show a distinction between ultramafic-hosted and basalt-hosted hydrothermal systems. The highest energy yield for chemolithotrophic catabolism in ultramafic-hosted hydrothermal systems is reached at low temperature and under slightly aerobic to aerobic conditions. The dominant reactions, for example at Rainbow or Lost City, are the oxidation of H2, Fe2+ and methane. At temperatures >60 °C, anaerobic metabolic reactions, e. g., sulphate reduction and methanogenesis, become more profitable. In contrast, basalt-hosted systems, such as TAG and 21 °N EPR uniformly indicate H2S oxidation to be the catabolically dominant reaction over the entire microbial-relevant temperature range. Affinities were calculated for the formation of individual cellular

  1. Deep-Sea Origin and In-Situ Diversification of Chrysogorgiid Octocorals

    PubMed Central

    Pante, Eric; France, Scott C.; Couloux, Arnaud; Cruaud, Corinne; McFadden, Catherine S.; Samadi, Sarah; Watling, Les

    2012-01-01

    The diversity, ubiquity and prevalence in deep waters of the octocoral family Chrysogorgiidae Verrill, 1883 make it noteworthy as a model system to study radiation and diversification in the deep sea. Here we provide the first comprehensive phylogenetic analysis of the Chrysogorgiidae, and compare phylogeny and depth distribution. Phylogenetic relationships among 10 of 14 currently-described Chrysogorgiidae genera were inferred based on mitochondrial (mtMutS, cox1) and nuclear (18S) markers. Bathymetric distribution was estimated from multiple sources, including museum records, a literature review, and our own sampling records (985 stations, 2345 specimens). Genetic analyses suggest that the Chrysogorgiidae as currently described is a polyphyletic family. Shallow-water genera, and two of eight deep-water genera, appear more closely related to other octocoral families than to the remainder of the monophyletic, deep-water chrysogorgiid genera. Monophyletic chrysogorgiids are composed of strictly (Iridogorgia Verrill, 1883, Metallogorgia Versluys, 1902, Radicipes Stearns, 1883, Pseudochrysogorgia Pante & France, 2010) and predominantly (Chrysogorgia Duchassaing & Michelotti, 1864) deep-sea genera that diversified in situ. This group is sister to gold corals (Primnoidae Milne Edwards, 1857) and deep-sea bamboo corals (Keratoisidinae Gray, 1870), whose diversity also peaks in the deep sea. Nine species of Chrysogorgia that were described from depths shallower than 200 m, and mtMutS haplotypes sequenced from specimens sampled as shallow as 101 m, suggest a shallow-water emergence of some Chrysogorgia species. PMID:22723855

  2. Molecular evidence that deep-branching fungi are major fungal components in deep-sea methane cold-seep sediments.

    PubMed

    Nagahama, Takahiko; Takahashi, Eriko; Nagano, Yuriko; Abdel-Wahab, Mohamed A; Miyazaki, Masayuki

    2011-08-01

    The motile cells of chytrids were once believed to be relics from the time before the colonization of land by fungi. However, the majority of chytrids had not been found in marine but freshwater environments. We investigated fungal diversity by a fungal-specific PCR-based analysis of environmental DNA in deep-sea methane cold-seep sediments, identifying a total of 35 phylotypes, 12 of which were early diverging fungi (basal fungi, ex 'lower fungi'). The basal fungi occupied a major portion of fungal clones. These were phylogenetically placed into a deep-branching clade of fungi and the LKM11 clade that was a divergent group comprised of only environmental clones from aquatic environments. As suggested by Lara and colleagues, species of the endoparasitic genus Rozella, being recently considered of the earliest branching taxa of fungi, were nested within the LKM11 clade. In the remaining 23 phylotypes identified as the Dikarya, the majority of which were similar to those which appeared in previously deep-sea studies, but also highly novel lineages associated with Soil Clone Group I (SCGI), Entorrhiza sp. and the agaricomycetous fungi were recorded. The fungi of the Dikarya may play a role in the biodegradation of lignin and lignin-derived materials in deep-sea, because the characterized fungal species related to the frequent phylotypes within the Dikarya have been reported to possess an ability to degrade lignin.

  3. Geochemical evidence for anoxic deep water in the Arabian Sea during the last glaciation

    SciTech Connect

    Sarkar, A.; Bhattacharya, S.K.; Sarin, M.M. )

    1993-03-01

    Various paleoceanographic studies have indicated that the deep ocean was probably depleted in dissolved oxygen during the last glacial period ([approximately]18 kyr B.P.; [delta][sup 18]O, stage 2) compared to present time. However, direct evidence of low oxygen content in the deep waters has been lacking. Here, the authors report geochemical evidence of near anoxic conditions in the deep Arabian Sea during the entire last glacial cycle ([delta][sup 18]O; stages 2, 3, and 4). Anoxia is inferred from the concomitant enrichment of organic carbon and authigenic uranium in the glacial sections of a core from the deep eastern Arabian Sea. The anoxic conditions during the last glacial period, probably caused by a change in deep water circulation, evidently enhanced preservation of organic matter and simultaneous removal of uranium from seawater. 57 refs., 3 figs., 2 tabs.

  4. Gravity deposits in deep sea fans and on Continental Slopes, Black Sea

    SciTech Connect

    Ivanov, M.K.; Konyukhov, A.I.

    1988-08-01

    The Danube fan has a classical structure. It is clearly expressed in the bottom relief and traced by reflection profiles for more than 200 km. The fan body is levee valley, which splits in a mid-fan area into numerous meandering distributaries. The fan consists of gravity and hemipelagic deposits. These are mainly turbidites of various compositions. Channels are filled with grain-flow deposits (sand), debris-flow deposits (sandy clay with shells), and slides from valley walls (mud, sapropelic mud). Levees in upper and mid-fan areas are formed by specific turbidite sequences: mudstone crumbs in the base, thinly laminated silt and clays in the middle, blue mud on the top. Hemipelagic sediments increase noticeably on outer slopes of the levees. In the Pleistocene sequences these are mud; in the Holocene, sapropelic mud and coccolith-diatom ooze. Distal turbidites are widespread in the lower fan areas. In the base of each cycle is a thin sand-silt layer with unclear graded bedding; the upper part is represented by mud. Reflection profiles demonstrate an ancient fan system with buried channels and levees. Configurations of these bodies are very similar to those of the modern fans. The sedimentary lens on the sea floor opposite the mouths of submarine canyons of the Rioni, Inguri, Kodori, Supsa, and Chorokh Rivers was formed by overlapped modern and ancient fans. The Inguri and Rioni produced a practically single submarine fan, the largest in this area. It is rather well expressed morphologically and traced by reflection profiles for more than 100 km. In its lower part it overlays a number of small fans. The Rioni-Inguri fan is smaller than the Danube, but the whole system of overlapped fans occupies an area of about 17,000 km/sup 2/, being more than 3 km thick. The composition and structure of sediments in this deep-sea system change sharply, depending on the geomorphological position.

  5. An autonomous underwater telescope for measuring the scattering of light in the deep sea

    NASA Astrophysics Data System (ADS)

    Balasi, K. G.; Domvoglou, T.; Kiskiras, I.; Lenis, D.; Maniatis, M.; Maragos, N.; Stavropoulos, G.

    2016-05-01

    The KM3NeT research infrastructure will be a deep sea multidisciplinary observatory in the Mediterranean Sea housing a neutrino telescope. Accurate knowledge of the optical properties of the sea water is important for the performance evaluation of the telescope. In this work we describe the deployment of the equipment that we had previously examined by Monte Carlo (MC) simulationsl, in the context of the scattering experiment in order to evaluate the parameters describing the scattering characteristics of the sea water. Four photomultipliers (PMTs) were used to measure in situ the scattered light emitted by six laser diodes in three different wavelengths covering the Cherenkov radiation spectrum.

  6. Microsporidia-nematode associations in methane seeps reveal basal fungal parasitism in the deep sea

    PubMed Central

    Sapir, Amir; Dillman, Adler R.; Connon, Stephanie A.; Grupe, Benjamin M.; Ingels, Jeroen; Mundo-Ocampo, Manuel; Levin, Lisa A.; Baldwin, James G.; Orphan, Victoria J.; Sternberg, Paul W.

    2013-01-01

    The deep sea is Earth's largest habitat but little is known about the nature of deep-sea parasitism. In contrast to a few characterized cases of bacterial and protistan parasites, the existence and biological significance of deep-sea parasitic fungi is yet to be understood. Here we report the discovery of a fungus-related parasitic microsporidium, Nematocenator marisprofundi n. gen. n. sp. that infects benthic nematodes at methane seeps on the Pacific Ocean floor. This infection is species-specific and has been temporally and spatially stable over 2 years of sampling, indicating an ecologically consistent host-parasite interaction. A high distribution of spores in the reproductive tracts of infected males and females and their absence from host nematodes' intestines suggests a sexual transmission strategy in contrast to the fecal-oral transmission of most microsporidia. N. marisprofundi targets the host's body wall muscles causing cell lysis, and in severe infection even muscle filament degradation. Phylogenetic analyses placed N. marisprofundi in a novel and basal clade not closely related to any described microsporidia clade, suggesting either that microsporidia-nematode parasitism occurred early in microsporidia evolution or that host specialization occurred late in an ancient deep-sea microsporidian lineage. Our findings reveal that methane seeps support complex ecosystems involving interkingdom interactions between bacteria, nematodes, and parasitic fungi and that microsporidia parasitism exists also in the deep-sea biosphere. PMID:24575084

  7. Microsporidia-nematode associations in methane seeps reveal basal fungal parasitism in the deep sea.

    PubMed

    Sapir, Amir; Dillman, Adler R; Connon, Stephanie A; Grupe, Benjamin M; Ingels, Jeroen; Mundo-Ocampo, Manuel; Levin, Lisa A; Baldwin, James G; Orphan, Victoria J; Sternberg, Paul W

    2014-01-01

    The deep sea is Earth's largest habitat but little is known about the nature of deep-sea parasitism. In contrast to a few characterized cases of bacterial and protistan parasites, the existence and biological significance of deep-sea parasitic fungi is yet to be understood. Here we report the discovery of a fungus-related parasitic microsporidium, Nematocenator marisprofundi n. gen. n. sp. that infects benthic nematodes at methane seeps on the Pacific Ocean floor. This infection is species-specific and has been temporally and spatially stable over 2 years of sampling, indicating an ecologically consistent host-parasite interaction. A high distribution of spores in the reproductive tracts of infected males and females and their absence from host nematodes' intestines suggests a sexual transmission strategy in contrast to the fecal-oral transmission of most microsporidia. N. marisprofundi targets the host's body wall muscles causing cell lysis, and in severe infection even muscle filament degradation. Phylogenetic analyses placed N. marisprofundi in a novel and basal clade not closely related to any described microsporidia clade, suggesting either that microsporidia-nematode parasitism occurred early in microsporidia evolution or that host specialization occurred late in an ancient deep-sea microsporidian lineage. Our findings reveal that methane seeps support complex ecosystems involving interkingdom interactions between bacteria, nematodes, and parasitic fungi and that microsporidia parasitism exists also in the deep-sea biosphere.

  8. Effects of hydrostatic pressure on yeasts isolated from deep-sea hydrothermal vents.

    PubMed

    Burgaud, Gaëtan; Hué, Nguyen Thi Minh; Arzur, Danielle; Coton, Monika; Perrier-Cornet, Jean-Marie; Jebbar, Mohamed; Barbier, Georges

    2015-11-01

    Hydrostatic pressure plays a significant role in the distribution of life in the biosphere. Knowledge of deep-sea piezotolerant and (hyper)piezophilic bacteria and archaea diversity has been well documented, along with their specific adaptations to cope with high hydrostatic pressure (HHP). Recent investigations of deep-sea microbial community compositions have shown unexpected micro-eukaryotic communities, mainly dominated by fungi. Molecular methods such as next-generation sequencing have been used for SSU rRNA gene sequencing to reveal fungal taxa. Currently, a difficult but fascinating challenge for marine mycologists is to create deep-sea marine fungus culture collections and assess their ability to cope with pressure. Indeed, although there is no universal genetic marker for piezoresistance, physiological analyses provide concrete relevant data for estimating their adaptations and understanding the role of fungal communities in the abyss. The present study investigated morphological and physiological responses of fungi to HHP using a collection of deep-sea yeasts as a model. The aim was to determine whether deep-sea yeasts were able to tolerate different HHP and if they were metabolically active. Here we report an unexpected taxonomic-based dichotomic response to pressure with piezosensitve ascomycetes and piezotolerant basidiomycetes, and distinct morphological switches triggered by pressure for certain strains.

  9. Latitudinal gradients of species richness in the deep-sea benthos of the North Atlantic.

    PubMed

    Rex, M A; Stuart, C T; Coyne, G

    2000-04-11

    Latitudinal species diversity gradients (LSDGs) in the Northern Hemisphere are the most well established biogeographic patterns on Earth. Despite long-standing interest in LSDGs as a central problem in ecology, their explanation remains uncertain. In terrestrial as well as coastal and pelagic marine ecosystems, these poleward declines in diversity typically have been represented and interpreted in terms of species richness, the number of coexisting species. Newly discovered LSDGs in the bathyal (500-4,000 m) benthos of the North Atlantic may help to resolve the underlying causes of these large-scale trends because the deep sea is such a physically distinct environment. However, a major problem in comparing surface and deep-sea LSDGs is that the latter have been measured differently, by using species diversity indices that are affected by both species richness and the evenness of relative abundance. Here, we demonstrate that deep-sea isopods, gastropods, and bivalves in the North Atlantic do exhibit poleward decreases in species richness, just as those found in other environments. A comprehensive systematic revision of the largest deep-sea gastropod family (Turridae) has provided a unique database on geographic distributions that is directly comparable to those used to document LSDGs in surface biotas. This taxon also shows a poleward decline in the number of species. Seasonal organic enrichment from sinking phytodetritus is the most plausible ecological explanation for deep-sea LSDGs and is the environmental factor most consistently associated with depressed diversity in a variety of bathyal habitats.

  10. Cosmopolitanism and Biogeography of the Genus Manganonema (Nematoda: Monhysterida) in the Deep Sea.

    PubMed

    Zeppilli, Daniela; Vanreusel, Ann; Danovaro, Roberto

    2011-09-05

    Spatial patterns of species diversity provide information about the mechanisms that regulate biodiversity and are important for setting conservation priorities. Present knowledge of the biogeography of meiofauna in the deep sea is scarce. This investigation focuses on the distribution of the deep-sea nematode genus Manganonema, which is typically extremely rare in deep-sea sediment samples. Forty-four specimens of eight different species of this genus were recorded from different Atlantic and Mediterranean regions. Four out of the eight species encountered are new to science. We report here that this genus is widespread both in the Atlantic and in the Mediterranean Sea. These new findings together with literature information indicate that Manganonema is a cosmopolitan genus, inhabiting a variety of deep-sea habitats and oceans. Manganonema shows the highest diversity at water depths >4,000 m. Our data, therefore, indicate that this is preferentially an abyssal genus that is able, at the same time, to colonize specific habitats at depths shallower than 1,000 m. The analysis of the distribution of the genus Manganonema indicates the presence of large differences in dispersal strategies among different species, ranging from locally endemic to cosmopolitan. Lacking meroplanktonic larvae and having limited dispersal ability due to their small size, it has been hypothesized that nematodes have limited dispersal potential. However, the investigated deep-sea nematodes were present across different oceans covering macro-scale distances. Among the possible explanations (hydrological conditions, geographical and geological pathways, long-term processes, specific historical events), their apparent preference of colonizing highly hydrodynamic systems, could suggest that these infaunal organisms are transported by means of deep-sea benthic storms and turbidity currents over long distances.

  11. Impact of Deepwater Horizon spill on food supply to deep-sea benthos communities

    NASA Astrophysics Data System (ADS)

    Prouty, N. G.; Campbell, P. L.; Mienis, F.; Duineveld, G.; Demopoulos, A. W. J.; Ross, S. W.; Brooke, S.

    2016-02-01

    Deep-sea ecosystems encompass unique and often fragile communities that are sensitive to a variety of anthropogenic and natural impacts. After the 2010 Deepwater Horizon (DWH) oil spill, sampling efforts documented the acute impact of the spill on some deep-sea coral colonies. To investigate the impact of the DWH spill on quality and quantity of biomass delivered to the deep-sea, a suite of geochemical tracers (e.g., stable and radio-isotopes, lipid biomarkers, and compound-specific isotopes) was measured from monthly sediment trap samples deployed near a high-density deep-coral site in the Viosca Knoll area of the north-central Gulf of Mexico prior to (Oct-2008 to Sept-2009) and after the spill (Oct-10 to Sept-11). Marine (e.g., autochthonous) sources of organic matter (OM) dominated the sediment traps in both years, however after the spill, there was a pronounced reduction in marine-sourced OM, including a reduction in marine-sourced sterols and n-alkanes and a concomitant decrease in sediment trap organic carbon and pigment flux. Results from this study indicate a reduction in primary production and carbon export to the deep-sea in 2010-2011, at least 6-18 months after the spill started. Whereas satellite observations indicate an initial increase in phytoplankton biomass, results from this sediment trap study define a reduction in primary production and carbon export to the deep-sea community. In addition, a dilution from a low-14C carbon source (e.g., petro-carbon) was detected in the sediment trap samples after the spill, in conjunction with a change in the petrogenic composition. The data presented here fills a critical gap in our knowledge of biogeochemical processes and sub-acute impacts to the deep-sea that ensued after the 2010 DWH spill.

  12. Unexpected Positive Buoyancy in Deep Sea Sharks, Hexanchus griseus, and a Echinorhinus cookei.

    PubMed

    Nakamura, Itsumi; Meyer, Carl G; Sato, Katsufumi

    2015-01-01

    We do not expect non air-breathing aquatic animals to exhibit positive buoyancy. Sharks, for example, rely on oil-filled livers instead of gas-filled swim bladders to increase their buoyancy, but are nonetheless ubiquitously regarded as either negatively or neutrally buoyant. Deep-sea sharks have particularly large, oil-filled livers, and are believed to be neutrally buoyant in their natural habitat, but this has never been confirmed. To empirically determine the buoyancy status of two species of deep-sea sharks (bluntnose sixgill sharks, Hexanchus griseus, and a prickly shark, Echinorhinus cookei) in their natural habitat, we used accelerometer-magnetometer data loggers to measure their swimming performance. Both species of deep-sea sharks showed similar diel vertical migrations: they swam at depths of 200-300 m at night and deeper than 500 m during the day. Ambient water temperature was around 15°C at 200-300 m but below 7°C at depths greater than 500 m. During vertical movements, all deep-sea sharks showed higher swimming efforts during descent than ascent to maintain a given swimming speed, and were able to glide uphill for extended periods (several minutes), indicating that these deep-sea sharks are in fact positively buoyant in their natural habitats. This positive buoyancy may adaptive for stealthy hunting (i.e. upward gliding to surprise prey from underneath) or may facilitate evening upward migrations when muscle temperatures are coolest, and swimming most sluggish, after spending the day in deep, cold water. Positive buoyancy could potentially be widespread in fish conducting daily vertical migration in deep-sea habitats.

  13. Impact of Deepwater Horizon Spill on food supply to deep-sea benthos communities

    USGS Publications Warehouse

    Prouty, Nancy G.; Swarzenski, Pamela; Mienis, Furu; Duineveld, Gerald; Demopoulos, Amanda; Ross, Steve W.; Brooke, Sandra

    2016-01-01

    Deep-sea ecosystems encompass unique and often fragile communities that are sensitive to a variety of anthropogenic and natural impacts. After the 2010 Deepwater Horizon (DWH) oil spill, sampling efforts documented the acute impact of the spill on some deep-sea coral colonies. To investigate the impact of the DWH spill on quality and quantity of biomass delivered to the deep-sea, a suite of geochemical tracers (e.g., stable and radio-isotopes, lipid biomarkers, and compound specific isotopes) was measured from monthly sediment trap samples deployed near a high-density deep-coral site in the Viosca Knoll area of the north-central Gulf of Mexico prior to (Oct-2008 to Sept-2009) and after the spill (Oct-10 to Sept-11). Marine (e.g., autochthonous) sources of organic matter dominated the sediment traps in both years, however after the spill, there was a pronounced reduction in marinesourced OM, including a reduction in marine-sourced sterols and n-alkanes and a concomitant decrease in sediment trap organic carbon and pigment flux. Results from this study indicate a reduction in primary production and carbon export to the deep-sea in 2010-2011, at least 6-18 months after the spill started. Whereas satellite observations indicate an initial increase in phytoplankton biomass, results from this sediment trap study define a reduction in primary production and carbon export to the deep-sea community. In addition, a dilution from a low-14C carbon source (e.g., petrocarbon) was detected in the sediment trap samples after the spill, in conjunction with a change in the petrogenic composition. The data presented here fills a critical gap in our knowledge of biogeochemical processes and sub-acute impacts to the deep-sea that ensued after the 2010 DWH spill.

  14. Unexpected Positive Buoyancy in Deep Sea Sharks, Hexanchus griseus, and a Echinorhinus cookei

    PubMed Central

    Nakamura, Itsumi; Meyer, Carl G.; Sato, Katsufumi

    2015-01-01

    We do not expect non air-breathing aquatic animals to exhibit positive buoyancy. Sharks, for example, rely on oil-filled livers instead of gas-filled swim bladders to increase their buoyancy, but are nonetheless ubiquitously regarded as either negatively or neutrally buoyant. Deep-sea sharks have particularly large, oil-filled livers, and are believed to be neutrally buoyant in their natural habitat, but this has never been confirmed. To empirically determine the buoyancy status of two species of deep-sea sharks (bluntnose sixgill sharks, Hexanchus griseus, and a prickly shark, Echinorhinus cookei) in their natural habitat, we used accelerometer-magnetometer data loggers to measure their swimming performance. Both species of deep-sea sharks showed similar diel vertical migrations: they swam at depths of 200–300 m at night and deeper than 500 m during the day. Ambient water temperature was around 15°C at 200–300 m but below 7°C at depths greater than 500 m. During vertical movements, all deep-sea sharks showed higher swimming efforts during descent than ascent to maintain a given swimming speed, and were able to glide uphill for extended periods (several minutes), indicating that these deep-sea sharks are in fact positively buoyant in their natural habitats. This positive buoyancy may adaptive for stealthy hunting (i.e. upward gliding to surprise prey from underneath) or may facilitate evening upward migrations when muscle temperatures are coolest, and swimming most sluggish, after spending the day in deep, cold water. Positive buoyancy could potentially be widespread in fish conducting daily vertical migration in deep-sea habitats. PMID:26061525

  15. Deep-sea environment and biodiversity of the West African Equatorial margin

    NASA Astrophysics Data System (ADS)

    Sibuet, Myriam; Vangriesheim, Annick

    2009-12-01

    The long-term BIOZAIRE multidisciplinary deep-sea environmental program on the West Equatorial African margin organized in partnership between Ifremer and TOTAL aimed at characterizing the benthic community structure in relation with physical and chemical processes in a region of oil and gas interest. The morphology of the deep Congo submarine channel and the sedimentological structures of the deep-sea fan were established during the geological ZAIANGO project and helped to select study sites ranging from 350 to 4800 m water depth inside or near the channel and away from its influence. Ifremer conducted eight deep-sea cruises on board research vessels between 2000 and 2005. Standardized methods of sampling together with new technologies such as the ROV Victor 6000 and its associated instrumentation were used to investigate this poorly known continental margin. In addition to the study of sedimentary environments more or less influenced by turbidity events, the discovery of one of the largest cold seeps near the Congo channel and deep coral reefs extends our knowledge of the different habitats of this margin. This paper presents the background, objectives and major results of the BIOZAIRE Program. It highlights the work achieved in the 16 papers in this special issue. This synthesis paper describes the knowledge acquired at a regional and local scale of the Equatorial East Atlantic margin, and tackles new interdisciplinary questions to be answered in the various domains of physics, chemistry, taxonomy and ecology to better understand the deep-sea environment in the Gulf of Guinea.

  16. The transfer of river load to deep-sea fans: A quantitative approach

    SciTech Connect

    Wetzel, A. )

    1993-10-01

    Submarine fans and turbidite systems are major petroleum reservoirs in many sedimentary basins worldwide. The size of a river-fed deep-sea fan is controlled mainly by the amount of sediment available from a terrestrial source, whereas sea level fluctuations only trigger mass transfer to the deep sea. The deposition rate and fan length correlate for most fans formed on abyssal plains. Fan size is independent of depositional environment (lake or sea), time span, or geological period, which may be characterized by different amplitudes and frequencies of sea level fluctuations. In climatically stable regions such as the tropics about 25 [+-] 10% of the suspended river load reaching the river mouth is transported to the deep sea over the long term. The type of river mouth affects the amount of material transported to the deep sea; estuaries with deeply incised canyons may transfer 6-8 times more material than fluvial-dominated and lobate deltas, provided the suspended river load is equal in both cases. For most river-fed deep-sea fans, a well-defined geometry develops on unconfined abyssal plains. The width/length ratio is about 0.2 at the base of the slope, and reaches a maximum of 0.5 farther downward. This is in good agreement with flume experiments. The volume of such fans resting on a planar base is roughly 0.35 [times] area [times] maximum thickness. The quantitative relationships of fans with respect to geometry, deposition rate, and river suspended discharge may provide some basic for basin modeling and calculation of the sediment budget of erosional-depositional systems.

  17. Comparison of deep-water viromes from the atlantic ocean and the mediterranean sea.

    PubMed

    Winter, Christian; Garcia, Juan A L; Weinbauer, Markus G; DuBow, Michael S; Herndl, Gerhard J

    2014-01-01

    The aim of this study was to compare the composition of two deep-sea viral communities obtained from the Romanche Fracture Zone in the Atlantic Ocean (collected at 5200 m depth) and the southwest Mediterranean Sea (from 2400 m depth) using a pyro-sequencing approach. The results are based on 18.7% and 6.9% of the sequences obtained from the Atlantic Ocean and the Mediterranean Sea, respectively, with hits to genomes in the non-redundant viral RefSeq database. The identifiable richness and relative abundance in both viromes were dominated by archaeal and bacterial viruses accounting for 92.3% of the relative abundance in the Atlantic Ocean and for 83.6% in the Mediterranean Sea. Despite characteristic differences in hydrographic features between the sampling sites in the Atlantic Ocean and the Mediterranean Sea, 440 virus genomes were found in both viromes. An additional 431 virus genomes were identified in the Atlantic Ocean and 75 virus genomes were only found in the Mediterranean Sea. The results indicate that the rather contrasting deep-sea environments of the Atlantic Ocean and the Mediterranean Sea share a common core set of virus types constituting the majority of both virus communities in terms of relative abundance (Atlantic Ocean: 81.4%; Mediterranean Sea: 88.7%).

  18. Environmental selection of protistan plankton communities in hypersaline anoxic deep-sea basins, Eastern Mediterranean Sea

    PubMed Central

    Filker, Sabine; Stock, Alexandra; Breiner, Hans-Werner; Edgcomb, Virginia; Orsi, William; Yakimov, Michail M; Stoeck, Thorsten

    2013-01-01

    High salt concentrations, absence of light, anoxia, and high hydrostatic pressure make deep hypersaline anoxic basins (DHABs) in the Eastern Mediterranean Sea one of the most polyextreme habitats on Earth. Taking advantage of the unique chemical characteristics of these basins, we tested the effect of environmental selection and geographic distance on the structure of protistan communities. Terminal restriction fragment length polymorphism (T-RFLP) analyses were performed on water samples from the brines and seawater/brine interfaces of five basins: Discovery, Urania, Thetis, Tyro, and Medee. Using statistical analyses, we calculated the partitioning of diversity among the ten individual terminal restriction fragment (T-RF) profiles, based on peak abundance and peak incidence. While a significant distance effect on spatial protistan patterns was not detected, hydrochemical gradients emerged as strong dispersal barriers that likely lead to environmental selection in the DHAB protistan plankton communities. We identified sodium, magnesium, sulfate, and oxygen playing in concerto as dominant environmental drivers for the structuring of protistan plankton communities in the Eastern Mediterranean DHABs. PMID:23239531

  19. Transport of sludge-derived organic pollutants to deep-sea sediments at deep water dump site 106

    USGS Publications Warehouse

    Takada, H.; Farrington, J.W.; Bothner, Michael H.; Johnson, C.G.; Tripp, B.W.

    1994-01-01

    Linear alkylbenzenes (LABs), coprostanol and epi-coprostanol, were detected in sediment trap and bottom sediment samples at the Deep Water Dump Site 106 located 185 km off the coast of New Jersey, in water depths from 2400 to 2900 m. These findings clearly indicate that organic pollutants derived from dumped sludge are transported through the water column and have accumulated on the deep-sea floor. No significant difference in LABs isomeric composition was observed among sludge and samples, indicating little environmental biodegradation of these compounds. LABs and coprostanol have penetrated down to a depth of 6 cm in sediment, indicating the mixing of these compounds by biological and physical processes. Also, in artificially resuspended surface sediments, high concentrations of LABs and coprostanols were detected, implying that sewage-derived organic pollutants initially deposited on the deep-sea floor can be further dispersed by resuspension and transport processes. Small but significant amounts of coprostanol were detected in the sediment from a control site at which no LABs were detected. The coprostanol is probably derived from feces of marine mammals and sea birds and/or from microbial or geochemical transformations of cholesterol. Polcyclic aromatic hydrocarbons (PAHs) in sediment trap samples from the dump site were largely from the sewage sludge and had a mixed petroleum and pyrogenic composition. In contrast, PAHs in sediments in the dump site were mainly pyrogenic; contributed either from sewage sludge or from atmospheric transport to the overlying waters. & 1994 American Chemical Society.

  20. Lack of Spatial Subdivision for the Snapper Lutjanus purpureus (Lutjanidae – Perciformes) from Southwest Atlantic Based on Multi-Locus Analyses

    PubMed Central

    Sampaio, Iracilda; Schneider, Horacio

    2016-01-01

    The Caribbean snapper Lutjanus purpureus is a marine species fish commonly found associated with rocky seabeds and is widely distributed along of Western Atlantic. Data on stock delineation and stock recognition are essential for establishing conservation measures for commercially fished species. However, few studies have investigated the population genetic structure of this economically valuable species, and previous studies (based on only a portion of the mitochondrial DNA) provide an incomplete picture. The present study used a multi-locus approach (12 segments of mitochondrial and nuclear DNA) to elucidate the levels of genetic diversity and genetic connectivity of L. purpureus populations and their demographic history. L. purpureus has high levels of genetic diversity, which probably implies in high effective population sizes values for the species. The data show that this species is genetically homogeneous throughout the geographic region analyzed, most likely as a result of dispersal during larval phase. Regarding demographic history, a historical population growth event occurred, likely due to sea level changes during the Pleistocene. PMID:27556738

  1. Multi-locus species tree of the chub genus Squalius (Leuciscinae: Cyprinidae) from western Iberia: new insights into its evolutionary history.

    PubMed

    Waap, Silke; Amaral, Ana R; Gomes, Bruno; Manuela Coelho, M

    2011-08-01

    The phylogenetic relationships of the genus Squalius are believed to be well established based on the mitochondrial cytochrome b gene. Here, we inferred the phylogenetic relationships of all species inhabiting most of the western Iberia river systems using a nuclear multi-locus approach and different species tree methods: concatenation and coalescent-based methods (BEST and minimize-deep-coalescence). The dataset comprised sequences of seven coding and three non-coding regions belonging to seven nuclear genes, which were chosen to cover multiple biological functions: amh, bmp4, ef1a, egr2, irbp, rh and rpl8. We provide evidence for a conflicting topology between the nuDNA species tree and the widely reported mtDNA gene tree. S. pyrenaicus is rendered paraphyletic in all nuDNA species trees, with populations of the Tagus/Colares clustering with S. carolitertii, while populations from the Guadiana, Sado and Almargem form a separate clade. Although a larger sampling size encompassing the full spectrum of Squalius populations in western Iberia is still needed to fully elucidate the phylogeography and species delimitation of this genus, our results suggest that the two S. pyrenaicus clades may represent different species.

  2. Archaeal diversity and community development in deep-sea hydrothermal vents.

    PubMed

    Takai, Ken; Nakamura, Kentaro

    2011-06-01

    Over the past 35 years, researchers have explored deep-sea hydrothermal vent environments around the globe and studied a number of archaea, their unique metabolic and physiological properties, and their vast phylogenetic diversity. Although the pace of discovery of new archaeal taxa, phylotypes and phenotypes in deep-sea hydrothermal vents has slowed recently, bioinformatics and interdisciplinary geochemistry-microbiology approaches are providing new information on the diversity and community composition of archaea living in deep-sea vents. Recent investigations have revealed that archaea could have originated and dispersed from ancestral communities endemic to hydrothermal vents into other biomes on Earth, and the community structure and productivity of chemolithotrophic archaea are controlled primarily by variations in the geochemical composition of hydrothermal fluids.

  3. Macroecological drivers of archaea and bacteria in benthic deep-sea ecosystems.

    PubMed

    Danovaro, Roberto; Molari, Massimiliano; Corinaldesi, Cinzia; Dell'Anno, Antonio

    2016-04-01

    Bacteria and archaea dominate the biomass of benthic deep-sea ecosystems at all latitudes, playing a crucial role in global biogeochemical cycles, but their macroscale patterns and macroecological drivers are still largely unknown. We show the results of the most extensive field study conducted so far to investigate patterns and drivers of the distribution and structure of benthic prokaryote assemblages from 228 samples collected at latitudes comprising 34°N to 79°N, and from ca. 400- to 5570-m depth. We provide evidence that, in deep-sea ecosystems, benthic bacterial and archaeal abundances significantly increase from middle to high latitudes, with patterns more pronounced for archaea, and particularly for Marine Group I Thaumarchaeota. Our results also reveal that different microbial components show varying sensitivities to changes in temperature conditions and food supply. We conclude that climate change will primarily affect deep-sea benthic archaea, with important consequences on global biogeochemical cycles, particularly at high latitudes.

  4. Microbial gene functions enriched in the Deepwater Horizon deep-sea oil plume

    SciTech Connect

    Lu, Z.; Deng, Y.; Nostrand, J.D. Van; He, Z.; Voordeckers, J.; Zhou, A.; Lee, Y.-J.; Mason, O.U.; Dubinsky, E.; Chavarria, K.; Tom, L.; Fortney, J.; Lamendella, R.; Jansson, J.K.; D?haeseleer, P.; Hazen, T.C.; Zhou, J.

    2011-06-15

    The Deepwater Horizon oil spill in the Gulf of Mexico is the deepest and largest offshore spill in U.S. history and its impacts on marine ecosystems are largely unknown. Here, we showed that the microbial community functional composition and structure were dramatically altered in a deep-sea oil plume resulting from the spill. A variety of metabolic genes involved in both aerobic and anaerobic hydrocarbon degradation were highly enriched in the plume compared to outside the plume, indicating a great potential for intrinsic bioremediation or natural attenuation in the deep-sea. Various other microbial functional genes relevant to carbon, nitrogen, phosphorus, sulfur and iron cycling, metal resistance, and bacteriophage replication were also enriched in the plume. Together, these results suggest that the indigenous marine microbial communities could play a significant role in biodegradation of oil spills in deep-sea environments.

  5. Taxonomic revision of deep-sea Ostracoda from the Arctic Ocean

    USGS Publications Warehouse

    Yasuhara, Moriaki; Stepanova, Anna; Okahashi, Hisayo; Cronin, Thomas M.; Brouwers, Elisabeth M.

    2015-01-01

    Taxonomic revision of deep-sea Ostracoda from the Arctic Ocean was conducted to reduce taxonomic uncertainty that will improve our understanding of species ecology, biogeography and relationship to faunas from other deep-sea regions. Fifteen genera and 40 species were examined and (re-)illustrated with high-resolution scanning electron microscopy images, covering most of known deep-sea species in the central Arctic Ocean. Seven new species are described: Bythoceratina lomonosovensis n. sp., Cytheropteron parahamatum n. sp., Cytheropteron lanceae n. sp.,Cytheropteron irizukii n. sp., Pedicythere arctica n. sp., Cluthiawhatleyi n. sp., Krithe hunti n. sp. This study provides a robust taxonomic baseline for application to paleoceanographical reconstruction and biodiversity analyses in this climatically sensitive region.

  6. Ecological impacts of large-scale disposal of mining waste in the deep sea

    PubMed Central

    Hughes, David J.; Shimmield, Tracy M.; Black, Kenneth D.; Howe, John A.

    2015-01-01

    Deep-Sea Tailings Placement (DSTP) from terrestrial mines is one of several large-scale industrial activities now taking place in the deep sea. The scale and persistence of its impacts on seabed biota are unknown. We sampled around the Lihir and Misima island mines in Papua New Guinea to measure the impacts of ongoing DSTP and assess the state of benthic infaunal communities after its conclusion. At Lihir, where DSTP has operated continuously since 1996, abundance of sediment infauna was substantially reduced across the sampled depth range (800–2020 m), accompanied by changes in higher-taxon community structure, in comparison with unimpacted reference stations. At Misima, where DSTP took place for 15 years, ending in 2004, effects on community composition persisted 3.5 years after its conclusion. Active tailings deposition has severe impacts on deep-sea infaunal communities and these impacts are detectable at a coarse level of taxonomic resolution. PMID:25939397

  7. Lunar rhythms in the deep sea: evidence from the reproductive periodicity of several marine invertebrates.

    PubMed

    Mercier, Annie; Sun, Zhao; Baillon, Sandrine; Hamel, Jean-François

    2011-02-01

    While lunar rhythms are commonly documented in plants and animals living in terrestrial and shallow-water environments, deep-sea organisms have essentially been overlooked in that respect. This report describes evidence of lunar periodicity in the reproduction of 6 deep-sea species belonging to 2 phyla. Occurrences of gamete release in free spawners and larval release in brooders exhibited significant peaks around the new and full moons, respectively. The exact nature of this lunar period (endogenous or exogenous rhythm) and its adaptive significance in the deep sea remain elusive. Current knowledge suggests that proxies of moon phases at depth may include fluxes in particulate matter deposition, cyclic currents, and moonlight for species living in the disphotic zone.

  8. Late Pleistocene Sea level on the New Jersey Margin: Implications to eustasy and deep-sea temperature

    USGS Publications Warehouse

    Wright, J.D.; Sheridan, R.E.; Miller, K.G.; Uptegrove, J.; Cramer, B.S.; Browning, J.V.

    2009-01-01

    We assembled and dated a late Pleistocene sea-level record based on sequence stratigraphy from the New Jersey margin and compared it with published records from fossil uplifted coral reefs in New Guinea, Barbados, and Araki Island, as well as a composite sea-level estimate from scaling of Red Sea isotopic values. Radiocarbon dates, amino acid racemization data, and superposition constrain the ages of large (20-80??m) sea-level falls from New Jersey that correlate with Marine Isotope Chrons (MIC) 2, 3b, 4, 5b, and 6 (the past 130??kyr). The sea-level records for MIC 1, 2, 4, 5e, and 6 are similar to those reported from New Guinea, Barbados, Araki, and the Red Sea; some differences exist among records for MIC 3. Our record consistently provides the shallowest sea level estimates for MIC3 (??? 25-60??m below present); it agrees most closely with the New Guinea record of Chappell (2002; ??? 35-70??m), but contrasts with deeper estimates provided by Araki (??? 85-95??m) and the Red Sea (50-90??m). Comparison of eustatic estimates with benthic foraminiferal ??18O records shows that the deep sea cooled ??? 2.5????C between MIC 5e and 5d (??? 120-110??ka) and that near freezing conditions persisted until Termination 1a (14-15??ka). Sea-level variations between MIC 5b and 2 (ca. 90-20??ka) follow a well-accepted 0.1???/10??m linear variation predicted by ice-growth effects on foraminiferal ??18O values. The pattern of deep-sea cooling follows a previously established hysteresis loop between two stable modes of operation. Cold, near freezing deep-water conditions characterize most of the past 130??kyr punctuated only by two warm intervals (the Holocene/MIC 1 and MIC 5e). We link these variations to changes in Northern Component Water (NCW). ?? 2009 Elsevier B.V. All rights reserved.

  9. Predicted Deep-Sea Coral Habitat Suitability for the U.S. West Coast

    PubMed Central

    Guinotte, John M.; Davies, Andrew J.

    2014-01-01

    Regional scale habitat suitability models provide finer scale resolution and more focused predictions of where organisms may occur. Previous modelling approaches have focused primarily on local and/or global scales, while regional scale models have been relatively few. In this study, regional scale predictive habitat models are presented for deep-sea corals for the U.S. West Coast (California, Oregon and Washington). Model results are intended to aid in future research or mapping efforts and to assess potential coral habitat suitability both within and outside existing bottom trawl closures (i.e. Essential Fish Habitat (EFH)) and identify suitable habitat within U.S. National Marine Sanctuaries (NMS). Deep-sea coral habitat suitability was modelled at 500 m×500 m spatial resolution using a range of physical, chemical and environmental variables known or thought to influence the distribution of deep-sea corals. Using a spatial partitioning cross-validation approach, maximum entropy models identified slope, temperature, salinity and depth as important predictors for most deep-sea coral taxa. Large areas of highly suitable deep-sea coral habitat were predicted both within and outside of existing bottom trawl closures and NMS boundaries. Predicted habitat suitability over regional scales are not currently able to identify coral areas with pin point accuracy and probably overpredict actual coral distribution due to model limitations and unincorporated variables (i.e. data on distribution of hard substrate) that are known to limit their distribution. Predicted habitat results should be used in conjunction with multibeam bathymetry, geological mapping and other tools to guide future research efforts to areas with the highest probability of harboring deep-sea corals. Field validation of predicted habitat is needed to quantify model accuracy, particularly in areas that have not been sampled. PMID:24759613

  10. Submarine canyons: hotspots of benthic biomass and productivity in the deep sea.

    PubMed

    De Leo, Fabio C; Smith, Craig R; Rowden, Ashley A; Bowden, David A; Clark, Malcolm R

    2010-09-22

    Submarine canyons are dramatic and widespread topographic features crossing continental and island margins in all oceans. Canyons can be sites of enhanced organic-matter flux and deposition through entrainment of coastal detrital export, dense shelf-water cascade, channelling of resuspended particulate material and focusing of sediment deposition. Despite their unusual ecological characteristics and global distribution along oceanic continental margins, only scattered information is available about the influence of submarine canyons on deep-sea ecosystem structure and productivity. Here, we show that deep-sea canyons such as the Kaikoura Canyon on the eastern New Zealand margin (42 degrees 01' S, 173 degrees 03' E) can sustain enormous biomasses of infaunal megabenthic invertebrates over large areas. Our reported biomass values are 100-fold higher than those previously reported for deep-sea (non-chemosynthetic) habitats below 500 m in the ocean. We also present evidence from deep-sea-towed camera images that areas in the canyon that have the extraordinary benthic biomass also harbour high abundances of macrourid (rattail) fishes likely to be feeding on the macro- and megabenthos. Bottom-trawl catch data also indicate that the Kaikoura Canyon has dramatically higher abundances of benthic-feeding fishes than adjacent slopes. Our results demonstrate that the Kaikoura Canyon is one of the most productive habitats described so far in the deep sea. A new global inventory suggests there are at least 660 submarine canyons worldwide, approximately 100 of which could be biomass hotspots similar to the Kaikoura Canyon. The importance of such deep-sea canyons as potential hotspots of production and commercial fisheries yields merits substantial further study.

  11. Submarine canyons: hotspots of benthic biomass and productivity in the deep sea

    PubMed Central

    De Leo, Fabio C.; Smith, Craig R.; Rowden, Ashley A.; Bowden, David A.; Clark, Malcolm R.

    2010-01-01

    Submarine canyons are dramatic and widespread topographic features crossing continental and island margins in all oceans. Canyons can be sites of enhanced organic-matter flux and deposition through entrainment of coastal detrital export, dense shelf-water cascade, channelling of resuspended particulate material and focusing of sediment deposition. Despite their unusual ecological characteristics and global distribution along oceanic continental margins, only scattered information is available about the influence of submarine canyons on deep-sea ecosystem structure and productivity. Here, we show that deep-sea canyons such as the Kaikoura Canyon on the eastern New Zealand margin (42°01′ S, 173°03′ E) can sustain enormous biomasses of infaunal megabenthic invertebrates over large areas. Our reported biomass values are 100-fold higher than those previously reported for deep-sea (non-chemosynthetic) habitats below 500 m in the ocean. We also present evidence from deep-sea-towed camera images that areas in the canyon that have the extraordinary benthic biomass also harbour high abundances of macrourid (rattail) fishes likely to be feeding on the macro- and megabenthos. Bottom-trawl catch data also indicate that the Kaikoura Canyon has dramatically higher abundances of benthic-feeding fishes than adjacent slopes. Our results demonstrate that the Kaikoura Canyon is one of the most productive habitats described so far in the deep sea. A new global inventory suggests there are at least 660 submarine canyons worldwide, approximately 100 of which could be biomass hotspots similar to the Kaikoura Canyon. The importance of such deep-sea canyons as potential hotspots of production and commercial fisheries yields merits substantial further study. PMID:20444722

  12. Predicted deep-sea coral habitat suitability for the U.S. West coast.

    PubMed

    Guinotte, John M; Davies, Andrew J

    2014-01-01

    Regional scale habitat suitability models provide finer scale resolution and more focused predictions of where organisms may occur. Previous modelling approaches have focused primarily on local and/or global scales, while regional scale models have been relatively few. In this study, regional scale predictive habitat models are presented for deep-sea corals for the U.S. West Coast (California, Oregon and Washington). Model results are intended to aid in future research or mapping efforts and to assess potential coral habitat suitability both within and outside existing bottom trawl closures (i.e. Essential Fish Habitat (EFH)) and identify suitable habitat within U.S. National Marine Sanctuaries (NMS). Deep-sea coral habitat suitability was modelled at 500 m×500 m spatial resolution using a range of physical, chemical and environmental variables known or thought to influence the distribution of deep-sea corals. Using a spatial partitioning cross-validation approach, maximum entropy models identified slope, temperature, salinity and depth as important predictors for most deep-sea coral taxa. Large areas of highly suitable deep-sea coral habitat were predicted both within and outside of existing bottom trawl closures and NMS boundaries. Predicted habitat suitability over regional scales are not currently able to identify coral areas with pin point accuracy and probably overpredict actual coral distribution due to model limitations and unincorporated variables (i.e. data on distribution of hard substrate) that are known to limit their distribution. Predicted habitat results should be used in conjunction with multibeam bathymetry, geological mapping and other tools to guide future research efforts to areas with the highest probability of harboring deep-sea corals. Field validation of predicted habitat is needed to quantify model accuracy, particularly in areas that have not been sampled.

  13. Small-Scale Heterogeneity in Deep-Sea Nematode Communities around Biogenic Structures

    PubMed Central

    Hasemann, Christiane; Soltwedel, Thomas

    2011-01-01

    The unexpected high species richness of deep-sea sediments gives rise to the questions, which processes produce and maintain diversity in the deep sea, and at what spatial scales do these processes operate? The idea of a small-scale habitat structure at the deep-sea floor provides the background for this study. At small scales biogenic structures create a heterogeneous environment that influences the structure of the surrounding communities and the dynamics of the meiobenthic populations. As an example for biogenic structures, small deep-sea sponges (Tentorium semisuberites Schmidt 1870) and their sedimentary environment were investigated for small-scale distribution patterns of benthic deep-sea nematodes. Sampling was carried out with the remotely operated vehicle Victor 6000 at the Arctic deep-sea observatory HAUSGARTEN. In order to investigate nematode community patterns sediment cores around three small sponges and corresponding control cores were analysed. A total of approx. 5800 nematodes were identified. The comparison of the nematode communities from sponge and control samples indicated an influence of the biogenic structure “sponge” on diversity patterns and habitat heterogeneity. The increased number of nematode species and functional groups found in the sediments around the sponges suggest that on a small scale the sponge acts as a gradient and creates a more divers habitat structure. The nematode community from the sponge sediments shows a greater taxonomic variance and species richness together with lower relative abundances of the species compared to those from control sediments. Obviously, the more homogeneous habitat conditions of the control sediments offer less micro-habitats than the sediments around the sponges. This seems to reduce the number of functional groups and species coexisting in the control sediments. PMID:22216193

  14. Structure, functioning, and cumulative stressors of Mediterranean deep-sea ecosystems

    NASA Astrophysics Data System (ADS)

    Tecchio, Samuele; Coll, Marta; Sardà, Francisco

    2015-06-01

    Environmental stressors, such as climate fluctuations, and anthropogenic stressors, such as fishing, are of major concern for the management of deep-sea ecosystems. Deep-water habitats are limited by primary productivity and are mainly dependent on the vertical input of organic matter from the surface. Global change over the latest decades is imparting variations in primary productivity levels across oceans, and thus it has an impact on the amount of organic matter landing on the deep seafloor. In addition, anthropogenic impacts are now reaching the deep ocean. The Mediterranean Sea, the largest enclosed basin on the planet, is not an exception. However, ecosystem-level studies of response to varying food input and anthropogenic stressors on deep-sea ecosystems are still scant. We present here a comparative ecological network analysis of three food webs of the deep Mediterranean Sea, with contrasting trophic structure. After modelling the flows of these food webs with the Ecopath with Ecosim approach, we compared indicators of network structure and functioning. We then developed temporal dynamic simulations varying the organic matter input to evaluate its potential effect. Results show that, following the west-to-east gradient in the Mediterranean Sea of marine snow input, organic matter recycling increases, net production decreases to negative values and trophic organisation is overall reduced. The levels of food-web activity followed the gradient of organic matter availability at the seafloor, confirming that deep-water ecosystems directly depend on marine snow and are therefore influenced by variations of energy input, such as climate-driven changes. In addition, simulations of varying marine snow arrival at the seafloor, combined with the hypothesis of a possible fishery expansion on the lower continental slope in the western basin, evidence that the trawling fishery may pose an impact which could be an order of magnitude stronger than a climate

  15. Diversification of acorn worms (Hemichordata, Enteropneusta) revealed in the deep sea.

    PubMed

    Osborn, Karen J; Kuhnz, Linda A; Priede, Imants G; Urata, Makoto; Gebruk, Andrey V; Holland, Nicholas D

    2012-04-22

    Enteropneusts (phylum Hemichordata), although studied extensively because of their close relationship to chordates, have long been considered shallow-water, burrowing animals. The present paper more than doubles the number of enteropneust species recorded in the deep sea based on high-resolution imaging and sampling with remotely operated vehicles. We provide direct evidence that some enteropneusts are highly mobile-using changes in posture and currents to drift between feeding sites-and are prominent members of deep, epibenthic communities. In addition, we provide ecological information for each species. We also show that despite their great morphological diversity, most deep-living enteropneusts form a single clade (the rediagnosed family Torquaratoridae) on the basis of rDNA sequences and morphology of the proboscis skeleton and stomochord. The phylogenetic position of the torquaratorids indicates that the group, after evolving from near-shore ancestors, radiated extensively in the deep sea.

  16. Surface-generated mesoscale eddies transport deep-sea products from hydrothermal vents.

    PubMed

    Adams, Diane K; McGillicuddy, Dennis J; Zamudio, Luis; Thurnherr, Andreas M; Liang, Xinfeng; Rouxel, Olivier; German, Christopher R; Mullineaux, Lauren S

    2011-04-29

    Atmospheric forcing, which is known to have a strong influence on surface ocean dynamics and production, is typically not considered in studies of the deep sea. Our observations and models demonstrate an unexpected influence of surface-generated mesoscale eddies in the transport of hydrothermal vent efflux and of vent larvae away from the northern East Pacific Rise. Transport by these deep-reaching eddies provides a mechanism for spreading the hydrothermal chemical and heat flux into the deep-ocean interior and for dispersing propagules hundreds of kilometers between isolated and ephemeral communities. Because the eddies interacting with the East Pacific Rise are formed seasonally and are sensitive to phenomena such as El Niño, they have the potential to introduce seasonal to interannual atmospheric variations into the deep sea.

  17. The National Deep-Sea Coral and Sponge Database: A Comprehensive Resource for United States Deep-Sea Coral and Sponge Records

    NASA Astrophysics Data System (ADS)

    Dornback, M.; Hourigan, T.; Etnoyer, P.; McGuinn, R.; Cross, S. L.

    2014-12-01

    Research on deep-sea corals has expanded rapidly over the last two decades, as scientists began to realize their value as long-lived structural components of high biodiversity habitats and archives of environmental information. The NOAA Deep Sea Coral Research and Technology Program's National Database for Deep-Sea Corals and Sponges is a comprehensive resource for georeferenced data on these organisms in U.S. waters. The National Database currently includes more than 220,000 deep-sea coral records representing approximately 880 unique species. Database records from museum archives, commercial and scientific bycatch, and from journal publications provide baseline information with relatively coarse spatial resolution dating back as far as 1842. These data are complemented by modern, in-situ submersible observations with high spatial resolution, from surveys conducted by NOAA and NOAA partners. Management of high volumes of modern high-resolution observational data can be challenging. NOAA is working with our data partners to incorporate this occurrence data into the National Database, along with images and associated information related to geoposition, time, biology, taxonomy, environment, provenance, and accuracy. NOAA is also working to link associated datasets collected by our program's research, to properly archive them to the NOAA National Data Centers, to build a robust metadata record, and to establish a standard protocol to simplify the process. Access to the National Database is provided through an online mapping portal. The map displays point based records from the database. Records can be refined by taxon, region, time, and depth. The queries and extent used to view the map can also be used to download subsets of the database. The database, map, and website is already in use by NOAA, regional fishery management councils, and regional ocean planning bodies, but we envision it as a model that can expand to accommodate data on a global scale.

  18. First Insights into the Viral Communities of the Deep-sea Anoxic Brines of the Red Sea.

    PubMed

    Antunes, André; Alam, Intikhab; Simões, Marta Filipa; Daniels, Camille; Ferreira, Ari J S; Siam, Rania; El-Dorry, Hamza; Bajic, Vladimir B

    2015-10-01

    The deep-sea brines of the Red Sea include some of the most extreme and unique environments on Earth. They combine high salinities with increases in temperature, heavy metals, hydrostatic pressure, and anoxic conditions, creating unique settings for thriving populations of novel extremophiles. Despite a recent increase of studies focusing on these unusual biotopes, their viral communities remain unexplored. The current survey explores four metagenomic datasets obtained from different brine-seawater interface samples, focusing specifically on the diversity of their viral communities. Data analysis confirmed that the particle-attached viral communities present in the brine-seawater interfaces were diverse and generally dominated by Caudovirales, yet appearing distinct from sample to sample. With a level of caution, we report the unexpected finding of Phycodnaviridae, which infects algae and plants, and trace amounts of insect-infecting Iridoviridae. Results from Kebrit Deep revealed stratification in the viral communities present in the interface: the upper-interface was enriched with viruses associated with typical marine bacteria, while the lower-interface was enriched with haloviruses and halophages. These results provide first insights into the unexplored viral communities present in deep-sea brines of the Red Sea, representing one of the first steps for ongoing and future sampling efforts and studies.

  19. Evolution and biogeography of deep-sea vent and seep invertebrates.

    PubMed

    Van Dover, C L; German, C R; Speer, K G; Parson, L M; Vrijenhoek, R C

    2002-02-15

    Deep-sea hydrothermal vents and cold seeps are submarine springs where nutrient-rich fluids emanate from the sea floor. Vent and seep ecosystems occur in a variety of geological settings throughout the global ocean and support food webs based on chemoautotrophic primary production. Most vent and seep invertebrates arrive at suitable habitats as larvae dispersed by deep-ocean currents. The recent evolution of many vent and seep invertebrate species (<100 million years ago) suggests that Cenozoic tectonic history and oceanic circulation patterns have been important in defining contemporary biogeographic patterns.

  20. Size distribution of interplanetary iron and stony particles related with deep-sea spherules

    NASA Technical Reports Server (NTRS)

    Matsuzaki, H.; Yamakoshi, K.

    1993-01-01

    To study origin and evolution of the interplanetary dust, it is very important to investigate the size distribution. Here the changes of the size distributions of meteoroid particles due to the ablative effects during atmospheric entry were investigated by numerical computer simulation. Using the results, the pre-atmospheric size distributions of the interplanetary dust particles could be estimated from that of ablated spherules taken from deep-sea sediments. We are now analyzing deep-sea spherules from some aspects and examining if we could get any information about the interplanetary dust.

  1. Thermodynamic and functional characteristics of deep-sea enzymes revealed by pressure effects.

    PubMed

    Ohmae, Eiji; Miyashita, Yurina; Kato, Chiaki

    2013-09-01

    Hydrostatic pressure analysis is an ideal approach for studying protein dynamics and hydration. The development of full ocean depth submersibles and high pressure biological techniques allows us to investigate enzymes from deep-sea organisms at the molecular level. The aim of this review was to overview the thermodynamic and functional characteristics of deep-sea enzymes as revealed by pressure axis analysis after giving a brief introduction to the thermodynamic principles underlying the effects of pressure on the structural stability and function of enzymes.

  2. In-situ measurements of bottom boundary layer processes in the deep South China Sea

    NASA Astrophysics Data System (ADS)

    Xu, J.; Li, J.; Zhang, Y.; Zhao, Y.; Liu, Z.; Ferreira, J. C. T.; Tate, G.

    2014-12-01

    As part of the South China Sea Deep project, we deployed a free-ascending tripod (FAT) on the sea floor of northern South China Sea at a water depth of 1900 m. During the 5-month deployment, the tripod hosted a suite of acoustic and optical oceanographic instruments that simultaneously measured time-series of 3-D velocity structure of the near bottom flows, temperature and salinity, water turbidity (sediment concentration), and particle size variations. A camera system and an acoustic altimeter closely monitored fine scale changes of the sea floor that could have resulted from either physical processes (erosion/deposition) or biological activities. Our goal of the tripod work, first-ever such study in South China Sea, along with several subsurface moorings that were also collecting flow and sedimentological data in the area, was to investigate the bottom boundary layer (BBL) processes and the regional deep current circulation surrounding a large body of sediment deposit whose formation mechanism and origins of sediment are still unclear. In addition, the tripod instruments were set up to capture the in-situ BBL signature of passing "benthic storms" that are believed to be the most important BBL processes in deep ocean. This presentation also includes a brief description of the technological advances implemented in the FAT deep-water tripod.

  3. Disturbance of deep-sea environments induced by the M9.0 Tohoku Earthquake

    PubMed Central

    Kawagucci, Shinsuke; Yoshida, Yukari T.; Noguchi, Takuroh; Honda, Makio C.; Uchida, Hiroshi; Ishibashi, Hidenori; Nakagawa, Fumiko; Tsunogai, Urumu; Okamura, Kei; Takaki, Yoshihiro; Nunoura, Takuro; Miyazaki, Junichi; Hirai, Miho; Lin, Weiren; Kitazato, Hiroshi; Takai, Ken

    2012-01-01

    The impacts of the M9.0 Tohoku Earthquake on deep-sea environment were investigated 36 and 98 days after the event. The light transmission anomaly in the deep-sea water after 36 days became atypically greater (∼35%) and more extensive (thickness ∼1500 m) near the trench axis owing to the turbulent diffusion of fresh seafloor sediment, coordinated with potential seafloor displacement. In addition to the chemical influx associated with sediment diffusion, an influx of 13C-enriched methane from the deep sub-seafloor reservoirs was estimated. This isotopically unusual methane influx was possibly triggered by the earthquake and its aftershocks that subsequently induced changes in the sub-seafloor hydrogeologic structures. The whole prokaryotic biomass and the development of specific phylotypes in the deep-sea microbial communities could rise and fall at 36 and 98 days, respectively, after the event. We may capture the snap shots of post-earthquake disturbance in deep-sea chemistry and microbial community responses. PMID:22355782

  4. Temporal dynamics of deep-sea latitudinal species diversity gradient based on paleoceanographic/micropaleontologic data

    NASA Astrophysics Data System (ADS)

    Yasuhara, M.; Hunt, G.; Okahashi, H.

    2009-12-01

    Macroecology investigates large-scale ecological phenomena, such as regional-global trends in ecosystem properties and biodiversity, and is used to better understand recent human-induced ecosystem degradation. Paleoceanography investigates physical/chemical parameters, biogeochemical cycles, ocean circulation, and ocean-atmosphere interaction, but rarely includes ecosystem-scale biological processes. Here we adopt a macroecological approach to paleoceanography and present sediment core records of the temporal dynamics of deep-sea species diversity gradients using ostracodes from the equatorial Atlantic Ocean for the past four glacial-interglacial cycles. Results show unexpected instability and high amplitude fluctuations in species diversity in the tropical deep ocean. The results imply that the modern deep-sea latitudinal species diversity gradient is unexpectedly dynamic over short time intervals and collapsed during glacial periods. Unstable tropical diversity requires reconsideration of current ecological hypotheses about the generation and maintenance of biodiversity as they apply to the deep sea, and underscores the potential vulnerability and conservation importance of tropical deep-sea ecosystems.

  5. Southern Ocean deep-sea biodiversity—From patterns to processes

    NASA Astrophysics Data System (ADS)

    Brandt, Angelika; Ebbe, Brigitte

    2009-09-01

    The Southern Ocean is characterized by a narrow and deep shelf, an almost isothermal water column and a large area of deep sea surrounding Antarctica. However, knowledge of the deep-sea faunal composition, particularly in the Southern Ocean, is still scarce in comparison with shelf and upper slope environment. For that reason a deep-sea project was devoted to investigate this little-known area of the Southern Ocean. ANDEEP (ANtarctic benthic DEEP-sea biodiversity: colonisation history and recent community patterns) took place in 2002-2005 and provided first insights into the biodiversity and biogeography of Southern Ocean benthic animals from meio- to megafauna. The results with the very general patterns are outlined here. Based on the knowledge on biodiversity patterns gained through ANDEEP, a follow-up project, ANDEEP-SYSTCO (SYSTem COupling), was established in the international polar year in order to investigate the processes driving the biodiversity pattern observed. This expedition took place in 2007/2008 and only preliminary data can be presented at this stage given that the material was available for only a couple of months since the return of R.V. Polarstern. Some key results identified after the SYSTCO expedition are presented.

  6. The contribution of the Greenland and Barents Seas to the deep water of the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Swift, James H.; Takahashi, Taro; Livingston, Hugh D.

    1983-07-01

    The deep waters of the Arctic Ocean are traditionally held to be fed by an influx of Norwegian Sea Deep Water (NSDW) via the northward flowing West Spitsbergen Current. Discrete sample and CTD observations obtained from the Greenland-Spitsbergen Passage in August 1981 during the Transient Tracers in the Ocean (TTO) North Atlantic expedition showed a ≈ 100-m-thick layer of modified Greenland Sea Deep Water (GSDW: colder and fresher than NSDW) at 2500 m, spreading northward along the bottom of a deep, unimpeded channel, underneath the NSDW. Since the available data indicate that Arctic Ocean Deep Water (AODW) has a higher salinity than NSDW, mixing of NSDW and GSDW can not produce AODW. Therefore, other sources, such as the peripheral arctic shelf seas, must contribute dense saline water to the Arctic Ocean. Concentrations of 137Cs and 90Sr observed in AODW are greater than those observed in GSDW and NSDW. The concentrations of these radionuclides on the Barents Sea shelf are sufficiently high and in the correct relative proportions to support this proposition.

  7. Relationships between deep-sea tunicate populations west and east of the Straits of Gibraltar

    NASA Astrophysics Data System (ADS)

    Monniot, Claude; Monniot, Françoise

    Twenty-four species of tunicates were collected from deep bottoms on each side of the Gibraltar sill, in the adjacent Mediterranean Sea and Atlantic Ocean. In the Atlantic, stations bathed by Atlantic and Mediterranean waters were both sampled. No transport of ascidian taxa by the outflow of Mediterranean water into the Atlantic is apparent. The alternative hypothesis of an Atlantic origin of bathyal ascidian species in the Mediterranean Sea is proposed.

  8. Draft Genome Sequence of Pseudomonas pachastrellae Strain CCUG 46540T, a Deep-Sea Bacterium

    PubMed Central

    2017-01-01

    ABSTRACT Pseudomonas pachastrellae strain CCUG 46540T (KMM 330T) was isolated from a deep-sea sponge specimen collected in the Philippine Sea at a depth of 750 m. The draft genome has an estimated size of 4.0 Mb, exhibits a G+C content of 61.2 mol%, and is predicted to encode 3,592 proteins, including pathways for the degradation of aromatic compounds. PMID:28385850

  9. Deep-Diving California Sea Lions: Are they Pushing their Physiological Limit

    DTIC Science & Technology

    2013-09-30

    during descent of deep dives to values less than 10 beats min-1 (Fig.1). Such a low heart rate also limits the absorption and distribution of both...maintain arterial hemoglobin saturation above 90% during deep dives as long as 7 minutes (McDonald and Ponganis 2012; McDonald and Ponganis 2013). In...system, experiences significant hypoxemia with routine arterial hemoglobin desaturation to 10 to 20% (Meir et al. 2009). However, similar to the sea

  10. To what extent can specialized species succeed in the deep sea? The biology and trophic ecology of deep-sea spiny eels (Notacanthidae) in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Romeu, Oriol Rodríguez; Cartes, Joan E.; Solé, Montse; Carrassón, Maite

    2016-09-01

    found related with either depth or homogenization/stratification of the water column. This lack of changes in diet is probably attributable to the greater stability of the lower slope where P. rissoanus lives. Gut fullness was mainly correlated with surface Chlorophyll a recorded simultaneously with the fish sampling. Lactate dehydrogenase (LDH) activity was similar in the muscle of the two notacanthids (N. bonapartei=3.72-8.75 μmol/min/mg prot; P. rissoanus=7.56 μmol/min/mg prot). Values for N. bonapartei were the highest found compared to other deep-sea fish in the deep Mediterranean. This could be related with the special feeding behaviour of this species when it removes sessile prey from substrate.

  11. Distribution and Origin of Multiple Bottom Simulating Reflectors in the Danube Deep-Sea Fan, Black Sea

    NASA Astrophysics Data System (ADS)

    Zander, T.; Berndt, C.; Haeckel, M.; Klaucke, I.; Bialas, J.; Klaeschen, D.

    2015-12-01

    The sedimentary succession of the anoxic, deep Black Sea Basin is an ideal location for organic matter preservation and microbial methane generation. In the depth range of the gas hydrate stability zone (GHSZ) methane gas forms methane hydrates and presumably large accumulations of gas hydrate exist in porous sediments, such as those encountered on the Danube deep-sea fan. High-resolution P-Cable 3D seismic data reveals the character and distribution of up to four stacked bottom simulating reflectors (BSR) within the channel-levee systems of the Danube deep-sea fan. These anomalous BSRs were first described by Popescu et al. (2006). The geological processes that lead to multiple BSRs are still poorly understood. The theoretical base of the GHSZ calculated from regional temperature gradients and salinity data is in agreement with the shallowest BSR in the area. We have tested two hypotheses that may explain the formation of the lower BSRs. The first hypothesis is that the lower BSRs are formed by overpressure compartments. Large amounts of free gas below the BSRs are trapped in the pore space increasing the pressure above hydrostatic condition up to a level where gas hydrates are stable again. The second hypothesis is that the lower BSRs are linked to the growth of the Danube fan. Sediment deposits from the outer levee of the youngest channel cover the area hosting multiple BSRs. The youngest channel developed during the last sea level lowstand that is correlated with the Neo-Euxinian that started 23,000 yrs. BP. We propose that the rapid sediment loading during sea level lowstands is a key factor for the preservation of paleo-BSRs in the study area. References Popescu, I., De Batist, M., Lericolais, G., Nouzé, H., Poort, J., Panin, N., Versteeg, W., Gillet, H., 2006. Multiple bottom-simulating reflections in the Black Sea: Potential proxies of past climate conditions. Marine Geology 227, 163-176.

  12. Extreme Dead Sea drying event during the last interglacial from the ICDP Dead Sea Deep Drill Core

    NASA Astrophysics Data System (ADS)

    Goldstein, S.; Stein, M.; Ben-Avraham, Z.; Agnon, A.; Ariztegui, D.; Brauer, A.; Haug, G.; Ito, E.; Kitagawa, H.; Torfstein, A.; Yasuda, Y.

    2012-04-01

    The ICDP funded Dead Sea Deep Drilling Project (DSDDP) recovered the longest and most complete paleo-environmental record in the Middle East, drilling holes in a deep and a shallow site extending to ~450 meters. The Dead Sea expands during the glacials and contracts during interglacials, and the sediments are an archive of the evolving climatic conditions. During glacials the sediments comprise intervals of marl (aragonite, gypsum and detritus) and during interglacials they are salts and marls. We estimate that the deep site core spans ~200 kyr (to early MIS 7). A dramatic discovery is a ~40 cm interval of rounded pebbles at ~235 m below the lake floor, the only clean pebbly unit in the entire core. It appears to be a beach layer, near the deepest part of the Dead Sea, lying above ~35 meters of mainly salt. If it is a beach layer, it implies an almost complete dry-down of the paleo-Dead Sea. The pebble layer lies within the last interglacial interval. Our initial attempt to estimate the age of the possible dry down shows an intriguing correlation between the salt-mud stratigraphy of the Dead Sea core and the oxygen isotope record of Soreq Cave, whereby excursions to light oxygen in the speleothems correspond to periods of salt deposition. Through this comparison, we estimate that the dry down occurred during MIS 5e. The occurrence of ~35 meters of mainly salt along with the pebble layer demonstrates a severe dry interval during MIS 5. This observation has implications for the Middle East today, where the Dead Sea level is dropping as all the countries in the area use the runoff. GCM models indicate a more arid future in the region. The core shows that the runoff nearly stopped during a past warm period without human intervention.

  13. Deep-sea weathering and erosion records of monsoon variations in the northern South China Sea

    NASA Astrophysics Data System (ADS)

    Clift, P. D.; Hu, D.; Böning, P.; Wan, S.; Brumsack, H.

    2012-04-01

    In this study we have examined the changes in a number of commonly used proxies for chemical weathering intensity in the northern South China Sea at ODP Site 1144 and in the delta of the Pearl River. Sediment at ODP Site 1144 is dominantly eroded from Taiwan and shows a sharp increase in the state of weathering of sediment deposited after 12 ka, reaching a peak at 10 ka and then decreasing to a lower background level after ~7 ka. The higher hematite/goethite values suggest more arid weathering despite the monsoon intensification at this time. Mass accumulation rates, Sr isotopes, Rb/K, kaolinite/(illite + chlorite) and Ti/Ca all show increases in this time period, although the frequently used CIA does not show a clear response. We suggest that the pulse of sediment represents enhanced erosion of the exposed continental shelf during a period of strong monsoon. This erosion was brought to an end by the flooding of the Taiwan Strait during sealevel rise after 8 ka. Although the sediment was originally from Taiwan the strong weathering is not an immediate response to climate change but represents the accumulated weathering of the shelf during sealevel low stands. As a result deep-water sedimentary weathering records provide us with a history that cannot be directly matched to the climatic history at the time of sedimentation. In contrast, sediment buffering appears to be less important in the Pearl River delta. In this setting provenance is clear and the deposits show sediment with intensity weathering in the Early Holocene, decreasing in strength during the Holocene as the summer rains weakened.

  14. A synthesis of genetic connectivity in deep-sea fauna and implications for marine reserve design.

    PubMed

    Baco, Amy R; Etter, Ron J; Ribeiro, Pedro A; von der Heyden, Sophie; Beerli, Peter; Kinlan, Brian P

    2016-07-01

    With anthropogenic impacts rapidly advancing into deeper waters, there is growing interest in establishing deep-sea marine protected areas (MPAs) or reserves. Reserve design depends on estimates of connectivity and scales of dispersal for the taxa of interest. Deep-sea taxa are hypothesized to disperse greater distances than shallow-water taxa, which implies that reserves would need to be larger in size and networks could be more widely spaced; however, this paradigm has not been tested. We compiled population genetic studies of deep-sea fauna and estimated dispersal distances for 51 studies using a method based on isolation-by-distance slopes. Estimates of dispersal distance ranged from 0.24 km to 2028 km with a geometric mean of 33.2 km and differed in relation to taxonomic and life-history factors as well as several study parameters. Dispersal distances were generally greater for fishes than invertebrates with the Mollusca being the least dispersive sampled phylum. Species that are pelagic as adults were more dispersive than those with sessile or sedentary lifestyles. Benthic species from soft-substrate habitats were generally less dispersive than species from hard substrate, demersal or pelagic habitats. As expected, species with pelagic and/or feeding (planktotrophic) larvae were more dispersive than other larval types. Many of these comparisons were confounded by taxonomic or other life-history differences (e.g. fishes being more dispersive than invertebrates) making any simple interpretation difficult. Our results provide the first rough estimate of the range of dispersal distances in the deep sea and allow comparisons to shallow-water assemblages. Overall, dispersal distances were greater for deeper taxa, although the differences were not large (0.3-0.6 orders of magnitude between means), and imbalanced sampling of shallow and deep taxa complicates any simple interpretation. Our analyses suggest the scales of dispersal and connectivity for reserve design

  15. Thermal Inactivation of a Deep-Sea Barophilic Bacterium, Isolate CNPT-3

    PubMed Central

    Yayanos, A. Aristides; Dietz, Allan S.

    1982-01-01

    The barophilic deep-sea bacterium, isolate CNPT-3, was inactivated by exposures to temperatures between 10 and 32°C at atmospheric pressure. Inactivation in samples from warmed cell suspensions was measured as the loss of colonyforming ability (CFA) at 10°C and 587 bars. At atmospheric pressure, there was a slow loss of CFA even at 10°C. The loss of CFA was rapid above 20°C and only slightly affected by high pressures. The first-order rate constants for thermal inactivation fit the Arrhenius equation with an activation energy of 43 kcal (ca. 179.9 kJ)/mol. Light microscopy and scanning transmission electron microscopy revealed morphological changes due to warming of the cells. The changes ensued the loss of CFA. The results supported the hypothesis from an earlier work that indigenous (autochthonous) deep-sea bacteria from cold deep seas are both barophilic and psychrophilic. If ultimately sustained, these characteristics may be useful in designing experiments to assess the relative importance of the autochthonous and allochthonous bacteria in the deep sea. The data were used to evaluate how barophilic bacteria may have been missed in many investigations because of warming of the cells during sample retrieval from the sea or during cultivation in the laboratory. The evaluation revealed the need for temperature and pressure data during retrieval of samples and cultivation in the laboratory. Most deep-ocean microbiology may be possible with thermally insulated equipment for retrieval from the sea and with high-pressure vessels for laboratory incubations. Images PMID:16346041

  16. Sensitivity of the deep-sea amphipod Eurythenes gryllus to chemically dispersed oil.

    PubMed

    Olsen, Gro Harlaug; Coquillé, Nathalie; Le Floch, Stephane; Geraudie, Perrine; Dussauze, Matthieu; Lemaire, Philippe; Camus, Lionel

    2016-04-01

    In the context of an oil spill accident and the following oil spill response, much attention is given to the use of dispersants. Dispersants are used to disperse an oil slick from the sea surface into the water column generating a cloud of dispersed oil droplets. The main consequence is an increasing of the sea water-oil interface which induces an increase of the oil biodegradation. Hence, the use of dispersants can be effective in preventing oiling of sensitive coastal environments. Also, in case of an oil blowout from the seabed, subsea injection of dispersants may offer some benefits compared to containment and recovery of the oil or in situ burning operation at the sea surface. However, biological effects of dispersed oil are poorly understood for deep-sea species. Most effects studies on dispersed oil and also other oil-related compounds have been focusing on more shallow water species. This is the first approach to assess the sensitivity of a macro-benthic deep-sea organism to dispersed oil. This paper describes a toxicity test which was performed on the macro-benthic deep-sea amphipod (Eurythenes gryllus) to determine the concentration causing lethality to 50% of test individuals (LC50) after an exposure to dispersed Brut Arabian Light (BAL) oil. The LC50 (24 h) was 101 and 24 mg L(-1) after 72 h and 12 mg L(-1) at 96 h. Based on EPA scale of toxicity categories to aquatic organisms, an LC50 (96 h) of 12 mg L(-1) indicates that the dispersed oil was slightly to moderately toxic to E. gryllus. As an attempt to compare our results to others, a literature study was performed. Due to limited amount of data available for dispersed oil and amphipods, information on other crustacean species and other oil-related compounds was also collected. Only one study on dispersed oil and amphipods was found, the LC50 value in this study was similar to the LC50 value of E. gryllus in our study. Since toxicity data are important input to risk assessment and net environmental

  17. Exploring fungal diversity in deep-sea sediments from Okinawa Trough using high-throughput Illumina sequencing

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao-Yong; Wang, Guang-Hua; Xu, Xin-Ya; Nong, Xu-Hua; Wang, Jie; Amin, Muhammad; Qi, Shu-Hua

    2016-10-01

    The present study investigated the fungal diversity in four different deep-sea sediments from Okinawa Trough using high-throughput Illumina sequencing of the nuclear ribosomal internal transcribed spacer-1 (ITS1). A total of 40,297 fungal ITS1 sequences clustered into 420 operational taxonomic units (OTUs) with 97% sequence similarity and 170 taxa were recovered from these sediments. Most ITS1 sequences (78%) belonged to the phylum Ascomycota, followed by Basidiomycota (17.3%), Zygomycota (1.5%) and Chytridiomycota (0.8%), and a small proportion (2.4%) belonged to unassigned fungal phyla. Compared with previous studies on fungal diversity of sediments from deep-sea environments by culture-dependent approach and clone library analysis, the present result suggested that Illumina sequencing had been dramatically accelerating the discovery of fungal community of deep-sea sediments. Furthermore, our results revealed that Sordariomycetes was the most diverse and abundant fungal class in this study, challenging the traditional view that the diversity of Sordariomycetes phylotypes was low in the deep-sea environments. In addition, more than 12 taxa accounted for 21.5% sequences were found to be rarely reported as deep-sea fungi, suggesting the deep-sea sediments from Okinawa Trough harbored a plethora of different fungal communities compared with other deep-sea environments. To our knowledge, this study is the first exploration of the fungal diversity in deep-sea sediments from Okinawa Trough using high-throughput Illumina sequencing.

  18. Genome Sequence of the Deep-Sea Denitrifier Pseudomonas sp. Strain MT-1, Isolated from the Mariana Trench.

    PubMed

    Fujinami, Shun; Oikawa, Yuji; Araki, Takuma; Shinmura, Yui; Midorikawa, Ryota; Ishizaka, Hikari; Kato, Chiaki; Horikoshi, Koki; Ito, Masahiro; Tamegai, Hideyuki

    2014-12-18

    Pseudomonas sp. strain MT-1 was the first deep-sea denitrifier isolated and characterized from mud recovered from a depth of 11,000 m in the Mariana Trench. We report here the genome sequence of this bacterium, which contributes to our understanding of denitrification and bioenergetics in the deep sea.

  19. 76 FR 36511 - Fisheries of the Northeastern United States; Atlantic Deep-Sea Red Crab; Amendment 3

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-22

    ... United States; Atlantic Deep-Sea Red Crab; Amendment 3 AGENCY: National Marine Fisheries Service (NMFS... Fishery Management Council (Council) has submitted Amendment 3 to the Atlantic Deep-Sea Red Crab Fishery... proposed to modify the existing trap limit regulations. The current trap limit regulations state that...

  20. One decade of thermohaline variability in the deep western Mediterranean Sea (2004-2014)

    NASA Astrophysics Data System (ADS)

    Schroeder, Katrin; Ismail, S. Ben; Bryden, Harry; Borghini, Mireno; Sparnocchia, Stefania; Chiggiato, Jacopo; Ribotti, Alberto

    2015-04-01

    Recent intense deep water formation events in the western Mediterranean have produced a huge amount of a new deep water. Significantly warmer and saltier than previously, it substituted the resident deep water. The deep structure and properties began to change after winter 2004/2005 and the water rapidly spread towards the interior of the basin, in the direction of the Strait of Gibraltar and within the Tyrrhenian Sea. The changes observed over the past 10 years are substantial: since 2004 we witnessed increases in deep water temperature and salinity 3-4 times faster than during 1961-2004. The possible impacts these changes could have on a global scale are still an open issue.

  1. A new look at deep-sea video

    USGS Publications Warehouse

    Chezar, H.; Lee, J.

    1985-01-01

    A deep-towed photographic system with completely self-contained recording instrumentation and power can obtain color-video and still-photographic transects along rough terrane without need for a long electrically conducting cable. Both the video- and still-camera systems utilize relatively inexpensive and proven off-the-shelf hardware adapted for deep-water environments. The small instrument frame makes the towed sled an ideal photographic tool for use on ship or small-boat operations. The system includes a temperature probe and altimeter that relay data acoustically from the sled to the surface ship. This relay enables the operator to monitor simultaneously water temperature and the precise height off the bottom. ?? 1985.

  2. Deep Seafloor Acoustic Backscattering Measurements Using Sea Beam

    DTIC Science & Technology

    1985-12-01

    seafloor down to maximum ocean depth (11 km). Since 1977 when the first system became operational aboard the French R/V Jean Charcot , nine other...Geological Observatory), Surveyor (National Oceanographic • and Atmospheric Administration), and Jean Charcot (IFREMER). Sea Beam •investigators who...1967. Renard, V. and J. P. Allenou, Seabeam, multi-beam echo-sounding in " Jean Charcot " . Description, evaluation and first results, Internat’l

  3. Deep Structures of the Palawan and Sulu Sea and Their Implications for Opening of the South China Sea

    NASA Astrophysics Data System (ADS)

    Liu, W.; Li, C. F.; Li, J.; Fairhead, D.; Zhou, Z.

    2014-12-01

    Compared to the northern South China Sea continental margin, the deep structures and tectonic evolution of the Palawan and Sulu Sea and ambient regions are not well understood so far. However, this part of the southern continental margin and adjacent areas embed critical information on the opening of the South China Sea (SCS). We carry out geophysical investigations using regional magnetic, gravity and reflection seismic data. Analytical signal amplitudes (ASA) of magnetic anomalies are calculated to depict the boundaries of different tectonic units. Curie-point depths are estimated from magnetic anomalies using a windowed wavenumber-domain algorithm. Application of the Parker-Oldenburg algorithm to Bouguer gravity anomalies yields a 3D Moho topography. The Palawan Continental Block (PCB) is defined by quiet magnetic anomalies, low ASA, moderate depths to the top and bottom of the magnetic layer, and its northern boundary is further constrained by reflection seismic data and Moho interpretation. However, the continent-ocean transition zone between the PCB and the SCS is characterized by hyper-extended continental crust intruded with magmatic bodies. The NW Sulu Sea is interpreted as a relict oceanic slice and the geometry and position of extinct trench of the Proto South China Sea (PSCS) is further constrained. With additional age constraints from inverted Moho and Curie-point depths, we confirm that the spreading of the SE Sulu Sea started in the Early Oligocene/Late Eocene due to the subduction of the PSCS, and terminated in the Middle Miocene by the obduction of the NW Sulu Sea onto the PCB. According to the newly constrained age of SE Sulu Sea, we also estimate the approximate extent, spreading rate and subducting rate of original SE Sulu Sea.

  4. Extreme drying event in the Dead Sea basin during MIS5 from the ICDP Dead Sea Deep Drill Core

    NASA Astrophysics Data System (ADS)

    Goldstein, S. L.; Stein, M.; Ben-Avraham, Z.; Agnon, A.; Ariztegui, D.; Brauer, A.; Haug, G. H.; Ito, E.; Kitagawa, H.; Torfstein, A.; Yasuda, Y.; The Icdp-Dsddp Scientific Party

    2011-12-01

    The ICDP funded Dead Sea Deep Drilling Project (DSDDP) recovered the longest and most complete paleo-environmental record in the Middle East, drilling holes of ~450 and ~350 meters in length in deep (~300 m below the lake level) and shallow sites (~3 mbll) respectively. The Dead Sea expands during the glacials and contracts during interglacials, and the sediments comprise a geological archive of the evolving environmental conditions (e.g. rains, floods, dust-storms, droughts). Dead Sea sediments include inorganic aragonite, allowing for dating by U-series (e.g. Haase-Schramm et al. GCA 2004). The deep site cores were opened and described in June 2011. The cores are composed mainly of alternating intervals of marl (aragonite, gypsum and detritus) during glacials, and salts and marls during interglacials. From this stratigraphy we estimate that the deep site core spans ~200 kyr (to the boundary of MIS 6 and 7). A dramatic discovery is a ~40 cm thick interval of partly rounded pebbles at ~235 m below the lake floor. This is the only clean pebbly unit in the entire core. It appears to be a beach layer, near the deepest part of the Dead Sea, lying above ~35 meters of mainly salt. If it is a beach layer, it implies an almost complete dry-down of the paleo-Dead Sea. The pebble layer lies within the last interglacial interval. Our initial attempt to more precisely estimate the age of the possible dry down shows an intriguing correlation between the salt-mud stratigraphy of the Dead Sea core and the oxygen isotope record of Soreq Cave, whereby excursions to light oxygen in the speleothems correspond to periods of salt deposition. Through this comparison, we estimate that the possible dry down occurred during MIS 5e. The occurrence of ~35 meters of mainly salt along with the pebble layer demonstrates a severe dry interval during MIS 5. This observation has implications for the Middle East today, where the Dead Sea level is dropping as all the countries in the area use the

  5. From deep-sea volcanoes to human pathogens: a conserved quorum-sensing signal in Epsilonproteobacteria

    PubMed Central

    Pérez-Rodríguez, Ileana; Bolognini, Marie; Ricci, Jessica; Bini, Elisabetta; Vetriani, Costantino

    2015-01-01

    Chemosynthetic Epsilonproteobacteria from deep-sea hydrothermal vents colonize substrates exposed to steep thermal and redox gradients. In many bacteria, substrate attachment, biofilm formation, expression of virulence genes and host colonization are partly controlled via a cell density-dependent mechanism involving signal molecules, known as quorum sensing. Within the Epsilonproteobacteria, quorum sensing has been investigated only in human pathogens that use the luxS/autoinducer-2 (AI-2) mechanism to control the expression of some of these functions. In this study we showed that luxS is conserved in Epsilonproteobacteria and that pathogenic and mesophilic members of this class inherited this gene from a thermophilic ancestor. Furthermore, we provide evidence that the luxS gene is expressed—and a quorum-sensing signal is produced—during growth of Sulfurovum lithotrophicum and Caminibacter mediatlanticus, two Epsilonproteobacteria from deep-sea hydrothermal vents. Finally, we detected luxS transcripts in Epsilonproteobacteria-dominated biofilm communities collected from deep-sea hydrothermal vents. Taken together, our findings indicate that the epsiloproteobacterial lineage of the LuxS enzyme originated in high-temperature geothermal environments and that, in vent Epsilonproteobacteria, luxS expression is linked to the production of AI-2 signals, which are likely produced in situ at deep-sea vents. We conclude that the luxS gene is part of the ancestral epsilonproteobacterial genome and represents an evolutionary link that connects thermophiles to human pathogens. PMID:25397946

  6. Ancient DNA complements microfossil record in deep-sea subsurface sediments.

    PubMed

    Lejzerowicz, Franck; Esling, Philippe; Majewski, Wojciech; Szczuciński, Witold; Decelle, Johan; Obadia, Cyril; Arbizu, Pedro Martinez; Pawlowski, Jan

    2013-08-23

    Deep-sea subsurface sediments are the most important archives of marine biodiversity. Until now, these archives were studied mainly using the microfossil record, disregarding large amounts of DNA accumulated on the deep-sea floor. Accessing ancient DNA (aDNA) molecules preserved down-core would offer unique insights into the history of marine biodiversity, including both fossilized and non-fossilized taxa. Here, we recover aDNA of eukaryotic origin across four cores collected at abyssal depths in the South Atlantic, in up to 32.5 thousand-year-old sediment layers. Our study focuses on Foraminifera and Radiolaria, two major groups of marine microfossils also comprising diverse non-fossilized taxa. We describe their assemblages in down-core sediment layers applying both micropalaeontological and environmental DNA sequencing approaches. Short fragments of the foraminiferal and radiolarian small subunit rRNA gene recovered from sedimentary DNA extracts provide evidence that eukaryotic aDNA is preserved in deep-sea sediments encompassing the last glacial maximum. Most aDNA were assigned to non-fossilized taxa that also dominate in molecular studies of modern environments. Our study reveals the potential of aDNA to better document the evolution of past marine ecosystems and opens new horizons for the development of deep-sea palaeogenomics.

  7. 'Lophenteropneust' hypothesis refuted by collection and photos of new deep-sea hemichordates.

    PubMed

    Holland, Nicholas D; Clague, David A; Gordon, Dennis P; Gebruk, Andrey; Pawson, David L; Vecchione, Michael

    2005-03-17

    The deep ocean is home to a group of broad-collared hemichordates--the so-called 'lophenteropneusts'--that have been photographed gliding on the sea floor but have not previously been collected. It has been claimed that these worms have collar tentacles and blend morphological features of the two main hemichordate body plans, namely the tentacle-less enteropneusts and the tentacle-bearing pterobranchs. Consequently, lophenteropneusts have been invoked as missing links to suggest that the former evolved into the latter. The most significant aspect of the lophenteropneust hypothesis is its prediction that the fundamental body plan within a basal phylum of deuterostomes was enteropneust-like. The assumption of such an ancestral state influences ideas about the evolution of the vertebrates from the invertebrates. Here we report on the first collected specimen of a broad-collared, deep-sea enteropneust and describe it as a new family, genus and species. The collar, although disproportionately broad, lacks tentacles. In addition, we find no evidence of tentacles in the available deep-sea photographs (published and unpublished) of broad-collared enteropneusts, including those formerly designated as lophenteropneusts. Thus, the lophenteropneust hypothesis was based on misinterpretation of deep-sea photographs of low quality and should no longer be used to support the idea that the enteropneust body plan is basal within the phylum Hemichordata.

  8. Microbial diversity and adaptation to high hydrostatic pressure in deep-sea hydrothermal vents prokaryotes.

    PubMed

    Jebbar, Mohamed; Franzetti, Bruno; Girard, Eric; Oger, Philippe

    2015-07-01

    Prokaryotes inhabiting in the deep sea vent ecosystem will thus experience harsh conditions of temperature, pH, salinity or high hydrostatic pressure (HHP) stress. Among the fifty-two piezophilic and piezotolerant prokaryotes isolated so far from different deep-sea environments, only fifteen (four Bacteria and eleven Archaea) that are true hyper/thermophiles and piezophiles have been isolated from deep-sea hydrothermal vents; these belong mainly to the Thermococcales order. Different strategies are used by microorganisms to thrive in deep-sea hydrothermal vents in which "extreme" physico-chemical conditions prevail and where non-adapted organisms cannot live, or even survive. HHP is known to impact the structure of several cellular components and functions, such as membrane fluidity, protein activity and structure. Physically the impact of pressure resembles a lowering of temperature, since it reinforces the structure of certain molecules, such as membrane lipids, and an increase in temperature, since it will also destabilize other structures, such as proteins. However, universal molecular signatures of HHP adaptation are not yet known and are still to be deciphered.

  9. Characterization of Bacterial Communities in Deep-Sea Hydrothermal Vents from Three Oceanic Regions.

    PubMed

    He, Tianliang; Zhang, Xiaobo

    2016-04-01

    Deep-sea hydrothermal vents are considered to be one of the most spectacular ecosystems on Earth. Microorganisms form the basis of the food chain in vents controlling the vent communities. However, the diversity of bacterial communities in deep-sea hydrothermal vents from different oceans remains largely unknown. In this study, the pyrosequencing of 16S rRNA gene was used to characterize the bacterial communities of the venting sulfide, seawater, and tubeworm trophosome from East Pacific Rise, South Atlantic Ridge, and Southwest Indian Ridge, respectively. A total of 23,767 operational taxonomic units (OTUs) were assigned into 42 different phyla. Although Proteobacteria, Actinobacteria, and Bacteroidetes were the predominant phyla in all vents, differences of bacterial diversity were observed among different vents from three oceanic regions. The sulfides of East Pacific Rise possessed the most diverse bacterial communities. The bacterial diversities of venting seawater were much lower than those of vent sulfides. The symbiotic bacteria of tubeworm Ridgeia piscesae were included in the bacterial community of vent sulfides, suggesting their significant ecological functions as the primary producers in the deep-sea hydrothermal vent ecosystems. Therefore, our study presented a comprehensive view of bacterial communities in deep-sea hydrothermal vents from different oceans.

  10. Deep-sea food web analysis using cross-reacting antisera

    NASA Astrophysics Data System (ADS)

    Feller, Robert J.; Zagursky, Gregory; Day, Elizabeth A.

    1985-04-01

    The high incidence of unrecognizable prey in the stomachs of deep-sea predators prompted the application of serological methods for identification of trophic connections. Antisera to whole-organism extracts of estuarine taxa cross-reacted with antigenic protein extracts of mid-water and deep-sea taxa along phylogenetically correct lines, indicating their potential as tools for gut contents immunoassay. Stomach, intestine, and rectum contents of grenadiers ( Coryphaenoides armatus) trapped at 2500 m in the North Atlantic were analyzed visually and with 32 antisera representing taxa from 10 common deep-sea phyla. While visual analysis only revealed the presence of fluids, parasites, crustacean exoskeletons, and gastropod opercula, the immunoassay indicated the presence of antigenic proteins from holothurian, anemone, gastropod, decapod, and foraminiferan prey in the same samples. This qualitative serological identification of prey at non-specific taxonomic levels provides evidence that benthic predation may be important within deep-sea communities. The immunoassay technique, although not a panacea for elucidating food web dynamics in remote environments, may be useful when other methods fail to identify trophic pathways.

  11. From principles to practice: a spatial approach to systematic conservation planning in the deep sea

    PubMed Central

    Wedding, L. M.; Friedlander, A. M.; Kittinger, J. N.; Watling, L.; Gaines, S. D.; Bennett, M.; Hardy, S. M.; Smith, C. R.

    2013-01-01

    Increases in the demand and price for industrial metals, combined with advances in technological capabilities have now made deep-sea mining more feasible and economically viable. In order to balance economic interests with the conservation of abyssal plain ecosystems, it is becoming increasingly important to develop a systematic approach to spatial management and zoning of the deep sea. Here, we describe an expert-driven systematic conservation planning process applied to inform science-based recommendations to the International Seabed Authority for a system of deep-sea marine protected areas (MPAs) to safeguard biodiversity and ecosystem function in an abyssal Pacific region targeted for nodule mining (e.g. the Clarion–Clipperton fracture zone, CCZ). Our use of geospatial analysis and expert opinion in forming the recommendations allowed us to stratify the proposed network by biophysical gradients, maximize the number of biologically unique seamounts within each subregion, and minimize socioeconomic impacts. The resulting proposal for an MPA network (nine replicate 400 × 400 km MPAs) covers 24% (1 440 000 km2) of the total CCZ planning region and serves as example of swift and pre-emptive conservation planning across an unprecedented area in the deep sea. As pressure from resource extraction increases in the future, the scientific guiding principles outlined in this research can serve as a basis for collaborative international approaches to ocean management. PMID:24197407

  12. From principles to practice: a spatial approach to systematic conservation planning in the deep sea.

    PubMed

    Wedding, L M; Friedlander, A M; Kittinger, J N; Watling, L; Gaines, S D; Bennett, M; Hardy, S M; Smith, C R

    2013-12-22

    Increases in the demand and price for industrial metals, combined with advances in technological capabilities have now made deep-sea mining more feasible and economically viable. In order to balance economic interests with the conservation of abyssal plain ecosystems, it is becoming increasingly important to develop a systematic approach to spatial management and zoning of the deep sea. Here, we describe an expert-driven systematic conservation planning process applied to inform science-based recommendations to the International Seabed Authority for a system of deep-sea marine protected areas (MPAs) to safeguard biodiversity and ecosystem function in an abyssal Pacific region targeted for nodule mining (e.g. the Clarion-Clipperton fracture zone, CCZ). Our use of geospatial analysis and expert opinion in forming the recommendations allowed us to stratify the proposed network by biophysical gradients, maximize the number of biologically unique seamounts within each subregion, and minimize socioeconomic impacts. The resulting proposal for an MPA network (nine replicate 400 × 400 km MPAs) covers 24% (1 440 000 km(2)) of the total CCZ planning region and serves as example of swift and pre-emptive conservation planning across an unprecedented area in the deep sea. As pressure from resource extraction increases in the future, the scientific guiding principles outlined in this research can serve as a basis for collaborative international approaches to ocean management.

  13. High fungal diversity and abundance recovered in the deep-sea sediments of the Pacific Ocean.

    PubMed

    Xu, Wei; Pang, Ka-Lai; Luo, Zhu-Hua

    2014-11-01

    Knowledge about the presence and ecological significance of bacteria and archaea in the deep-sea environments has been well recognized, but the eukaryotic microorganisms, such as fungi, have rarely been reported. The present study investigated the composition and abundance of fungal community in the deep-sea sediments of the Pacific Ocean. In this study, a total of 1,947 internal transcribed spacer (ITS) regions of fungal rRNA gene clones were recovered from five sediment samples at the Pacific Ocean (water depths ranging from 5,017 to 6,986 m) using three different PCR primer sets. There were 16, 17, and 15 different operational taxonomic units (OTUs) identified from fungal-universal, Ascomycota-, and Basidiomycota-specific clone libraries, respectively. Majority of the recovered sequences belonged to diverse phylotypes of Ascomycota (25 phylotypes) and Basidiomycota (18 phylotypes). The multiple primer approach totally recovered 27 phylotypes which showed low similarities (≤97 %) with available fungal sequences in the GenBank, suggesting possible new fungal taxa occurring in the deep-sea environments or belonging to taxa not represented in the GenBank. Our results also recovered high fungal LSU rRNA gene copy numbers (3.52 × 10(6) to 5.23 × 10(7)copies/g wet sediment) from the Pacific Ocean sediment samples, suggesting that the fungi might be involved in important ecological functions in the deep-sea environments.

  14. A Deep Sea Docking Station for ODYSSEY Class Autonomous Underwater Vehicles

    DTIC Science & Technology

    2007-11-02

    autonomous midwater missions. The Station is integrated into the main tension member of a deep sea mooring system. A large subsea flotation sphere supports...radio frequency communications. Primary subsystems of the Docking Station described in this report include a dock controller with multi- sensor support

  15. Deep Water Ocean Acoustics (DWOA): The Philippine Sea, OBSANP, and THAAW Experiments

    DTIC Science & Technology

    2015-09-30

    enabling advanced signal processing techniques to capitalize on the three-dimensional character of the sound and noise fields. OBJECTIVES...scattering by internal waves and spice (density- compensated temperature and salinity variations), (iv) characterizing the depth dependence and temporal...relationship between deep ocean ambient noise and sea surface processes that generate sound (Stephen et al., 2014). The experiment was motivated in part

  16. Telepresence-Enabled Remote Fieldwork: Undergraduate Research in the Deep Sea

    ERIC Educational Resources Information Center

    Stephens, A. Lynn; Pallant, Amy; McIntyre, Cynthia

    2016-01-01

    Deep-sea research is rarely available to undergraduate students. However, as telepresence technology becomes more available, doors may open for more undergraduates to pursue research that includes remote fieldwork. This descriptive case study is an initial investigation into whether such technology might provide a feasible opportunity for…

  17. From deep-sea volcanoes to human pathogens: a conserved quorum-sensing signal in Epsilonproteobacteria.

    PubMed

    Pérez-Rodríguez, Ileana; Bolognini, Marie; Ricci, Jessica; Bini, Elisabetta; Vetriani, Costantino

    2015-05-01

    Chemosynthetic Epsilonproteobacteria from deep-sea hydrothermal vents colonize substrates exposed to steep thermal and redox gradients. In many bacteria, substrate attachment, biofilm formation, expression of virulence genes and host colonization are partly controlled via a cell density-dependent mechanism involving signal molecules, known as quorum sensing. Within the Epsilonproteobacteria, quorum sensing has been investigated only in human pathogens that use the luxS/autoinducer-2 (AI-2) mechanism to control the expression of some of these functions. In this study we showed that luxS is conserved in Epsilonproteobacteria and that pathogenic and mesophilic members of this class inherited this gene from a thermophilic ancestor. Furthermore, we provide evidence that the luxS gene is expressed--and a quorum-sensing signal is produced--during growth of Sulfurovum lithotrophicum and Caminibacter mediatlanticus, two Epsilonproteobacteria from deep-sea hydrothermal vents. Finally, we detected luxS transcripts in Epsilonproteobacteria-dominated biofilm communities collected from deep-sea hydrothermal vents. Taken together, our findings indicate that the epsiloproteobacterial lineage of the LuxS enzyme originated in high-temperature geothermal environments and that, in vent Epsilonproteobacteria, luxS expression is linked to the production of AI-2 signals, which are likely produced in situ at deep-sea vents. We conclude that the luxS gene is part of the ancestral epsilonproteobacterial genome and represents an evolutionary link that connects thermophiles to human pathogens.

  18. Assessing benthic oxygen fluxes in oligotrophic deep sea sediments (HAUSGARTEN observatory)

    NASA Astrophysics Data System (ADS)

    Donis, Daphne; McGinnis, Daniel F.; Holtappels, Moritz; Felden, Janine; Wenzhoefer, Frank

    2016-05-01

    Benthic oxygen fluxes, an established proxy for total organic carbon mineralization, were investigated in oligotrophic deep sea sediments. We used three different in situ technologies to estimate the benthic oxygen fluxes at an Arctic deep sea site (2500 m depth, HAUSGARTEN observatory) with limiting conditions of low oxygen gradients and fluxes, low turbulence and low particle content in the benthic boundary layer. The resolved eddy covariance turbulent oxygen flux (-0.9±0.2 (SD) mmol O2 m-2 d-1) compared well with simultaneous dissolved oxygen flux measurements carried out with a microprofiler (-1.02±0.3 (SD) mmol O2 m-2 d-1) and total oxygen uptake obtained by benthic chamber incubations (-1.1±0.1 (SD) mmol O2 m-2 d-1). The agreement between these different techniques revealed that microbial-mediated oxygen consumption was dominant at this site. The average benthic flux equals a carbon mineralization rate of 4.3 g C m-2 yr-1, which exceeds the annual sedimentation of particulate organic matter measured by sediment traps. The present study represents a detailed comparison of different in situ technologies for benthic flux measurements at different spatial scales in oligotrophic deep sea sediments. The use of eddy covariance, so far rarely used for deep sea investigations, is presented in detail.

  19. Macondo oil in deep-sea sediments: Part 1 - sub-sea weathering of oil deposited on the seafloor.

    PubMed

    Stout, Scott A; Payne, James R

    2016-10-15

    Chemical analysis of sediment cores collected up to 8km from the Macondo well in 2010/2011 demonstrates the extent of weathering of the Macondo oil deposited in deep-sea sediments following the Deepwater Horizon disaster. On average, dissolution and biodegradation of the oil on the seafloor increased with distance from the well indicating that weathering occurred rapidly and overwhelmingly during the oil's transport as dispersed oil droplets within the deep-sea plume. Beyond about 5km from the well, the oil deposited on the seafloor had lost most mass below C25, was relatively enriched in n-C25+ n-alkanes and C3- and C4-alkylated benz[a]anthracenes/chrysenes, the latter owing to 95% depletion of total PAHs. Biodegradation of C28 and C29 tricyclic terpanes, C34 and C35 17α(H),21β(H)-homohopanes, C27 13β(H),17α(H)-dia and C27 14β(H),17β(H)-steranes and dissolution of C26 to C28 triaromatic steroids occurred. The results provide a means to distinguish Macondo oil in deep-sea sediments from naturally-occurring seep oils and pervasive ambient background hydrocarbons.

  20. [Deep-sea research ground for the study of living matter properties in extreme conditions].

    PubMed

    Polikarpov, G G

    2011-01-01

    The Black Sea hollow bottom is a promising research ground in the field of deep-sea radiochemoecology and exobiology. It has turned out to be at the intersection of the earth and cosmic scientific interests such as deep-sea marine radiochemoecology from the perspective of the study of extreme biogeocenological properties of the Earth biosphere and exobiology from the standpoint of the study of life phenomena (living matter) outside the Earth biosphere, i.e. on other planets and during hypothetical transfer of spores in the outer space. The potential of this ground is substantiated with the data published by the author and co-workers on accumulation of 90Sr, 137Cs and Pu isotopes with silts of bathyal pelo-contour, on the quality of deep-sea hydrogen sulphide waters (after their contact with air) for vital functions of planktonic and benthic aerobes, as well as the species composition of marine, freshwater and terrestrial plants grown from the spores collected from the bottom sediments of the Black Sea bathyal. Discussion was based on V.I. Vernadsky's ideas about the living matter and biosphere, which allowed conclusions about the biospheric and outer space role of the described phenomena.

  1. What depth should deep-sea water be pumped up from in the South China Sea for medicinal research?

    NASA Astrophysics Data System (ADS)

    He, Shan; Liu, Hongbing; Yang, Xue; Li, Chunxia; Guan, Huashi

    2013-03-01

    In this study, seawater was pumped up from 150, 200, 300, 500 and 1000 m in the South China Sea and analyzed to make certain what depth should deep-sea water (DSW) be pumped up for medicinal usage. The pumping depth of DSW was determined on the basis of chemical ingredients. The analyses of inorganic elements and dissolved organic matter (DOM) were performed by inductively coupled plasma mass spectrometry (ICP-MS) and ultra performance liquid chromatography-mass spectrometry (UPLC-MS) respectively. The raw data were used for hierarchical cluster analysis (HCA) and principal component analysis (PCA). The results showed that seawater pumped up from 500 m and 1000 m was similar in their chemical ingredients, and was different from the seawater pumped up from other depths. These results indicated that seawater from more than 500 m depth had relatively stable chemical ingredients and could be used as DSW in the South China Sea.

  2. Captive rearing of the deep-sea coral Eguchipsammia fistula from the Red Sea demonstrates remarkable physiological plasticity.

    PubMed

    Roik, Anna; Röthig, Till; Roder, Cornelia; Müller, Paul J; Voolstra, Christian R

    2015-01-01

    The presence of the cosmopolitan deep-sea coral Eguchipsammia fistula has recently been documented in the Red Sea, occurring in warm (>20 °C), oxygen- and nutrient-limited habitats. We collected colonies of this species from the central Red Sea that successfully resided in aquaria for more than one year. During this period the corals were exposed to increased oxygen levels and nutrition ad libitum unlike in their natural habitat. Specimens of long-term reared E. fistula colonies were incubated for 24 h and calcification (G) as well as respiration rates (R) were measured. In comparison to on-board measurements of G and R rates on freshly collected specimens, we found that G was increased while R was decreased. E. fistula shows extensive tissue growth and polyp proliferation in aquaculture and can be kept at conditions that notably differ from its natural habitat. Its ability to cope with rapid and prolonged changes in regard to prevailing environmental conditions indicates a wide physiological plasticity. This may explain in part the cosmopolitan distribution of this species and emphasizes its value as a deep-sea coral model to study mechanisms of acclimation and adaptation.

  3. Diterpenoid compounds and other lipids in deep-sea sediments and their geochemical significance

    NASA Technical Reports Server (NTRS)

    Simoneit, B. R. T.

    1977-01-01

    Cyclic diterpenoid compounds have been found by various investigators in the geosphere (e.g., fossil resins, coals, soil, shale, and deep-sea sediments). These compounds occur in significant amounts only in higher plants and are therefore potential markers of terrigenous plant lipids. Diterpenoids with the abietane skeleton (mainly dehydroabietic acid) have been identified in the lipids of sediment samples from the northeast Pacific Ocean, Black Sea, and North Atlantic Ocean. The presence of these resin-derived compounds was correlated with the terrigenous clay components and with the presence of pollen. The presence of polycyclic diterpenoids was also correlated with the distribution patterns and inferred sources of other sediment lipid constituents. Potamic transport, followed by turbidite redistribution, is the probable input mechanism of these resin-derived compounds to the deep-sea sediments. These diterpenoids appear to be excellent biological markers of resinous higher plants.

  4. New ultrasensitive pickup device for deep-sea robots: underwater super-HARP color TV camera

    NASA Astrophysics Data System (ADS)

    Maruyama, Hirotaka; Tanioka, Kenkichi; Uchida, Tetsuo

    1994-11-01

    An ultra-sensitive underwater super-HARP color TV camera has been developed. The characteristics -- spectral response, lag, etc. -- of the super-HARP tube had to be designed for use underwater because the propagation of light in water is very different from that in air, and also depends on the light's wavelength. The tubes have new electrostatic focusing and magnetic deflection functions and are arranged in parallel to miniaturize the camera. A deep sea robot (DOLPHIN 3K) was fitted with this camera and used for the first sea test in Sagami Bay, Japan. The underwater visual information was clear enough to promise significant improvements in both deep sea surveying and safety. It was thus confirmed that the Super- HARP camera is very effective for underwater use.

  5. Mercury in recent and century-old deep-sea fish. [Antimora rostrata

    SciTech Connect

    Barber, R.T.; Whaling, P.J.; Cohen, D.M.

    1984-01-01

    To determine if mercury discharges to the environment in the last century have increased the mercury content of marine fish, a sample of 21 specimens of one deep-sea fish species collected in the 1880s was compared with a sample of 66 specimens of the same species collected in the 1970s. The specimens of Antimore rostrata were collected from between 2000 and 3000 m in the western North Atlantic Ocean. In both recent and old fish mercury increased as a function of length, but comparison of the two concentration vs. length relationships shows that there has not been an increase in mercury concentration in deep-sea fish in the last century. This result supports the idea that the relatively high concentrations of mercury found in marine fish that inhabit the surface and deep waters of the open ocean result from natural processes, not 20th century industrial pollution.

  6. The bathymetric distribution of the digenean parasites of deep-sea fishes.

    PubMed

    Bray, Rodney A

    2004-06-01

    The bathymetric range of 149 digenean species recorded deeper than 200 m, the approximate depth of the continental shelf/slope break, are presented in graphical form. It is found that only representatives of the four families Lepocreadiidae, Fellodistomidae, Derogenidae and Hemiuridae reach to abyssal regions (>4000 m). Three other families, the Lecithasteridae, Zoogonidae and Opecoelidae, have truly deep-water forms reaching deeper than 3000 m. Bathymetric data are available for the Acanthocolpidae, Accacoeliidae, Bucephalidae, Cryptogonimidae, Faustulidae, Gorgoderidae, Monorchiidae and Sanguinicolidae showing that they reach deeper than 200 m. No bathymetric data are available for the members of the Bivesiculidae and Hirudinellidae which are reported from deep-sea hosts. These results indicate that only seventeen out of the 150 or so digenean families are reported in the deep sea.

  7. Deserts on the sea floor: Edward Forbes and his azoic hypothesis for a lifeless deep ocean.

    PubMed

    Anderson, Thomas R; Rice, Tony

    2006-12-01

    While dredging in the Aegean Sea during the mid-19th century, Manxman Edward Forbes noticed that plants and animals became progressively more impoverished the greater the depth they were from the surface of the water. By extrapolation Forbes proposed his now infamous azoic hypothesis, namely that life would be extinguished altogether in the murky depths of the deep ocean. The whole idea seemed so entirely logical given the enormous pressure, cold and eternal darkness of this apparently uninhabitable environment. Yet we now know that the sea floor is teeming with life. Curiously, it took 25 years for the azoic hypothesis to fall from grace. This was despite the presence of ample contrary evidence, including starfishes, worms and other organisms that seemingly originated from the deep seabed. This is a tale of scientists ignoring observations that ran counter to their deep-seated, yet entirely erroneous, beliefs.

  8. Larval Transport Modeling of Deep-Sea Invertebrates Can Aid the Search for Undiscovered Populations

    PubMed Central

    Yearsley, Jon M.; Sigwart, Julia D.

    2011-01-01

    Background Many deep-sea benthic animals occur in patchy distributions separated by thousands of kilometres, yet because deep-sea habitats are remote, little is known about their larval dispersal. Our novel method simulates dispersal by combining data from the Argo array of autonomous oceanographic probes, deep-sea ecological surveys, and comparative invertebrate physiology. The predicted particle tracks allow quantitative, testable predictions about the dispersal of benthic invertebrate larvae in the south-west Pacific. Principal Findings In a test case presented here, using non-feeding, non-swimming (lecithotrophic trochophore) larvae of polyplacophoran molluscs (chitons), we show that the likely dispersal pathways in a single generation are significantly shorter than the distances between the three known population centres in our study region. The large-scale density of chiton populations throughout our study region is potentially much greater than present survey data suggest, with intermediate ‘stepping stone’ populations yet to be discovered. Conclusions/Significance We present a new method that is broadly applicable to studies of the dispersal of deep-sea organisms. This test case demonstrates the power and potential applications of our new method, in generating quantitative, testable hypotheses at multiple levels to solve the mismatch between observed and expected distributions: probabilistic predictions of locations of intermediate populations, potential alternative dispersal mechanisms, and expected population genetic structure. The global Argo data have never previously been used to address benthic biology, and our method can be applied to any non-swimming larvae of the deep-sea, giving information upon dispersal corridors and population densities in habitats that remain intrinsically difficult to assess. PMID:21857992

  9. Evolutionary and biogeographical patterns of barnacles from deep-sea hydrothermal vents.

    PubMed

    Herrera, Santiago; Watanabe, Hiromi; Shank, Timothy M

    2015-02-01

    The characterization of evolutionary and biogeographical patterns is of fundamental importance to identify factors driving biodiversity. Due to their widespread but discontinuous distribution, deep-sea hydrothermal vent barnacles represent an excellent model for testing biogeographical hypotheses regarding the origin, dispersal and diversity of modern vent fauna. Here, we characterize the global genetic diversity of vent barnacles to infer their time of radiation, place of origin, mode of dispersal and diversification. Our approach was to target a suite of multiple loci in samples representing seven of the eight described genera. We also performed restriction-site associated DNA sequencing on individuals from each species. Phylogenetic inferences and topology hypothesis tests indicate that vent barnacles have colonized deep-sea hydrothermal vents at least twice in history. Consistent with preliminary estimates, we find a likely radiation of barnacles in vent ecosystems during the Cenozoic. Our analyses suggest that the western Pacific was the place of origin of the major vent barnacle lineage, followed by circumglobal colonization eastwards through the Southern Hemisphere during the Neogene. The inferred time of radiation rejects the classic hypotheses of antiquity of vent taxa. The timing and the mode of origin, radiation and dispersal are consistent with recent inferences made for other deep-sea taxa, including nonvent species, and are correlated with the occurrence of major geological events and mass extinctions. Thus, we suggest that the geological processes and dispersal mechanisms discussed here can explain the current distribution patterns of many other marine taxa and have played an important role shaping deep-sea faunal diversity. These results also constitute the critical baseline data with which to assess potential effects of anthropogenic disturbances on deep-sea ecosystems.

  10. Palaeocene-Eocene evolution of a specific group of extinct deep-sea benthic foraminifera.

    NASA Astrophysics Data System (ADS)

    van Kerckhoven, L.; Hayward, B. W.

    2009-04-01

    To increase the understanding of global evolution and extinction drivers in the deep sea, we study the enigmatic extinction of a distinctive group of cosmopolitan deep-sea benthic foraminifera during the late Pliocene-Middle Pleistocene "Last Global Extinction" (LGE) (3 - 0.12 Ma). The LGE was coeval with the pulsed expansion of the northern hemisphere ice cap, rendering deep-sea conditions colder and more oxygenated during increasingly severe glacials. The so-called "Extinction Group", comprising nearly 100 species (c. 25% of deep-sea foraminiferal diversity at that time), all shared a similar morphology of elongate, cylindrical and uniserial tests with small, specialised apertures. To elucidate the factors driving their evolution and ultimate extinction, we extend the studies back in time. During the Cenozoic, the deep-sea benthic foraminiferal community was stirred up by three more intervals of increased turnover (late Palaeocene-early Eocene, Late Eocene-earliest Oligocene and middle Miocene) all of which seem to have coincided with intervals of major climatic change. In a first stage of the research, we performed a low-resolution study of ODP Sites 689 and 1211 to obtain a record of the occurrence and abundance of the "Extinction Group" species throughout the Cenozoic. In a second phase, here presented, the research focuses on a high-resolution study of the "Extinction Group" species in ODP Sites 689 and 690 (Southern Ocean) through the Palaeocene-Eocene warm event, during which 30 to 50 % of benthic foraminiferal species went extinct. Focus on the Palaeocene-Eocene warm period, and investigation of whether this warm event had any impact on the "Extinction Group" species, indicates whether only the cold related events caused the loss of "Extinction Group" taxa and helps us to understand the extent to which the LGE was stress-related or temperature-related.

  11. Comparison of the oceanic deep convection in the Mediterranean and Irminger Seas

    NASA Astrophysics Data System (ADS)

    Caniaux, Guy; Piron, Anne; Thierry, Virginy; Mercier, Herlé; Giordani, Hervé

    2016-04-01

    Oceanic convection is an important process because it forms intermediate or deep waters that feed the global circulation. Convection is limited to a restricted number of sites in the world ocean. If deep convection in the north-western Mediterranean is well known, deep convection in the Irminger Sea (south-east of Greenland) has been established recently and its different phases (preconditioning, cyclonic circulation, buoyancy forcing) described only in the very last years. While the northwestern Mediterranean basin is known to be the site of the formation of the Western Mediterranean Deep Water (WMDW), the Irminger Sea participates to the formation of a certain amount of newly ventilated Labrador Sea Water (LSW). In both basins, intense surface heat loss is due to cold, dry and gale force wind events (respectively the northern Mistral and north-western Tramontane, and eastern tip jets to the east of Cape Farewell) during the autumn and winter periods. Cooling promotes the reinforcement of the circulation that leads to the increase of the north-western Mediterranean cyclonic gyre as well as the Irminger cyclonic gyre. Moreover elevated wind stress curl on the left side of the gale force wind pathways add to the preconditioning of the water column. These ingredients (surface cooling, reinforcement of the cyclonic circulation and Ekman pumping) may result, certain years, to intense convective overturning. In this presentation, we discuss the similarities and differences that characterize the different phases of deep convection that have affected the two basins during the last 15 years. Among the most striking differences, the Irminger Sea is an open basin directly influenced by its vicinity to the Labrador and the more northern seas, while the north-western Mediterranean basin appears more isolated: this difference may lead to distinct mechanisms in the preconditioning of the water masses.

  12. A continuum of life histories in deep-sea demersal fishes

    NASA Astrophysics Data System (ADS)

    Drazen, Jeffrey C.; Haedrich, Richard L.

    2012-03-01

    It is generally perceived that all deep-sea fishes have great longevity, slow growth, and low reproductive output in comparison to shelf dwelling species. However, such a dichotomy is too simplistic because some fishes living on continental slopes are relatively fecund and fast growing, important considerations in respect to the management of expanding deep-sea fisheries. We tested two hypotheses that might explain variation in life history attributes of commercially exploited demersal fishes: (1) phylogeny best explains the differences because deep-sea species are often in different families from shelf dwelling ones and, alternatively, (2) environmental factors affecting individual life history attributes that change with depth account for the observed variation. Our analysis was based on 40 species from 9 orders, including all major commercially exploited deep-sea fishes and several phylogenetically related shelf species. Depth of occurrence correlated significantly with age at 50% maturity increasing linearly with depth (r2=0.46), while the von Bertalanffy growth coefficient, maximum fecundity and potential rate of population increase declined significantly and exponentially with depth (r2=0.41, 0.25 and 0.53, respectively). These trends were still significant when phylogenetically independent contrasts were applied. The trends were also consistent with similar slopes amongst members of the order Gadiformes and the order Scorpaeniformes. Reduced temperatures, predation pressure, food availability, or metabolic rates may all contribute to such changes with depth. Regardless of the mechanisms, by analyzing a suite of fishes from the shelves to the slope the present analysis has shown that rather than a simple dichotomy between deep-sea fishes and shelf fishes there is a continuum of life history attributes in fishes which correlate strongly with depth of occurrence.

  13. Trophic ecology of deep-sea Asteroidea (Echinodermata) from eastern Canada

    NASA Astrophysics Data System (ADS)

    Gale, Katie S. P.; Hamel, Jean-François; Mercier, Annie

    2013-10-01

    Asteroids (sea stars) can be important predators in benthic communities and are often present in ecologically important and vulnerable deep-sea coral and sponge habitats. However, explicit studies on the trophic ecology of deep-sea asteroids are rare. We investigated the diets of seven species of deep-sea asteroid from the bathyal zone of Newfoundland and Labrador, eastern Canada. A multifaceted approach including live animal observations, stomach content analysis, and stable isotope analysis revealed the asteroids to be either top predators of megafauna or secondary consumers (mud ingesters, infaunal predators, and suspension feeders). The stable isotope signatures of Ceramaster granularis, Hippasteria phrygiana, and Mediaster bairdi are characteristic of high-level predators, having δ15N values 4.4‰ (more than one trophic level) above Ctenodiscus crispatus, Leptychaster arcticus, Novodinia americana, and Zoroaster fulgens. We present strong evidence that corals and sponges are common food items for two of the predatory species, C. granularis and H. phrygiana. During laboratory feeding trials, live H. phrygiana fed on several species of soft coral and C. granularis fed on sponges. Stomach content analysis of wild-caught individuals revealed sclerites from sea pens (e.g. Pennatula sp.) in the stomachs of both asteroid species; H. phrygiana also contained sclerites from at least two other species of octocoral and siliceous sponge spicules were present in the stomachs of C. granularis. The stomach contents of the secondary consumers contained a range of invertebrate material. Leptychaster arcticus and Ctenodiscus crispatus feed infaunally on bulk sediment and molluscs, Zoroaster fulgens is a generalist infaunal predator, and the brisingid Novodinia americana is a specialist suspension feeder on benthopelagic crustaceans. This study provides a foundation for understanding the ecological roles of bathyal asteroids, and suggests that some species may have the

  14. Deep-Sea Trench Microbiology Down to 10.9 Kilometers Below the Surface

    NASA Astrophysics Data System (ADS)

    Bartlett, D. H.

    2012-12-01

    Deep-sea trenches, extending to more than 10.9 km below the sea surface, are among the most remote and infrequently sampled habitats. As a result a global perspective of microbial diversity and adaptation is lacking in these extreme settings. I will present the results of studies of deep-sea trench microbes collected in the Puerto Rico Trench (PRT), Tonga Trench, New Britain Trench and Mariana Trench. The samples collected include sediment, seawater and animals in baited traps. The analyses to be described include microbial community activity and viability measurements as a function of hydrostatic pressure, microbial culturing at high pressure under various physiological conditions, phylogenetics and metagenome and single-cell genome characterizations. Most of the results to date stem from samples recovered from the PRT. The deep-sea PRT Trench microbes have more in common at the species level with other deep-sea microbial communities previously characterized in the Pacific Ocean and the Mediterranean Sea than with the microbial populations above them in shallow waters. They also harbor larger genomes with more genes assigned to signal transduction, transcription, replication, recombination and repair and inorganic ion transport. The overrepresented transporters in the PRT metagenome include di- and tri-carboxylate transporters that correspond to the prevailing catabolic processes such as butanoate, glyoxylate and dicarboxylate metabolism. A surprisingly high abundance of sulfatases for the degradation of sulfated polysaccharides were also present in the PRT. But, perhaps the most dramatic adaptational feature of the PRT microbes is heavy metal resistance, as reflected in the high numbers of metal efflux systems present. Single-cell genomics approaches have proven particularly useful for placing PRT metagenomic data into context.

  15. Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

    NASA Astrophysics Data System (ADS)

    Sant, T.; Buhagiar, D.; Farrugia, R. N.

    2014-06-01

    A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units.

  16. Mass sedimentation of the swimming crab Charybdis smithii (Crustacea: Decapoda) in the deep Arabian Sea

    NASA Astrophysics Data System (ADS)

    Christiansen, Bernd; Boetius, Antje

    During cruise Meteor 33/1 in the northern Arabian Sea in September/October 1995, large numbers of the portunid crab Charybdis smithii were observed swimming in the open ocean. In a photographic survey at three abyssal stations in the northern Arabian Sea (NAST, WAST, CAST), even higher densities of Charybdis smithii - up to 1 crab m -2 - were found dead on the sea floor. Average sizes of the crabs were around 34-44 mm carapace width, indicating that the animals died prematurely, before returning to the breeding grounds presumable on the shelves of India or Oman. The average weight of the crabs was 10-14 g wet weight. From the photographic quantification it can be deduced that these large food falls represent a significant carbon input of at least 10-30% of the annual flux of POC as measured in sediment traps in this region. The exceptionally high microbial chitinase activity in the surface sediment layers detected at the same stations indicates that this energy is utilized and channelled into the deep-sea benthic food web of the deep Arabian Sea. There are frequent observations of dense Charybdis smithii swarms in the Arabian Sea from different years; however, it is not certain whether such large food falls as observed during M 33/1 are regular seasonal events that repeat each year.

  17. The deep structure of a sea-floor hydrothermal deposit

    USGS Publications Warehouse

    Zierenberg, R.A.; Fouquet, Y.; Miller, D.J.; Bahr, J.M.; Baker, P.A.; Bjerkgard, T.; Brunner, C.A.; Duckworth, R.C.; Gable, R.; Gieskes, J.; Goodfellow, W.D.; Groschel-Becker, H. M.; Guerin, G.; Ishibashi, J.; Iturrino, G.; James, R.H.; Lackschewitz, K.S.; Marquez, L.L.; Nehlig, P.; Peter, J.M.; Rigsby, C.A.; Schultheiss, P.; Shanks, Wayne C.; Simoneit, B.R.T.; Summit, M.; Teagle, D.A.H.; Urbat, M.; Zuffa, G.G.

    1998-01-01

    Hydrothermal circulation at the crests of mid-ocean ridges plays an important role in transferring heat from the interior of the Earth. A consequence of this hydrothermal circulation is the formation of metallic ore bodies known as volcanic-associated massive sulphide deposits. Such deposits, preserved on land, were important sources of copper for ancient civilizations and continue to provide a significant source of base metals (for example, copper and zinc). Here we present results from Ocean Drilling Program Leg 169, which drilled through a massive sulphide deposit on the northern Juan de Fuca spreading centre and penetrated the hydrothermal feeder zone through which the metal-rich fluids reached the sea floor. We found that the style of feeder-zone mineralization changes with depth in response to changes in the pore pressure of the hydrothermal fluids and discovered a stratified zone of high-grade copper-rich replacement mineralization below the massive sulphide deposit. This copper-rich zone represents a type of mineralization not previously observed below sea-floor deposits, and may provide new targets for land-based mineral exploration.

  18. Giant deep-sea protist produces bilaterian-like traces.

    PubMed

    Matz, Mikhail V; Frank, Tamara M; Marshall, N Justin; Widder, Edith A; Johnsen, Sönke

    2008-12-09

    One of the strongest paleontological arguments in favor of the origin of bilaterally symmetrical animals (Bilateria) prior to their obvious and explosive appearance in the fossil record in the early Cambrian, 542 million years ago, is the occurrence of trace fossils shaped like elongated sinuous grooves or furrows in the Precambrian. Being restricted to the seafloor surface, these traces are relatively rare and of limited diversity, and they do not show any evidence of the use of hard appendages. They are commonly attributed to the activity of the early nonskeletonized bilaterians or, alternatively, large cnidarians such as sea anemones or sea pens. Here we describe macroscopic groove-like traces produced by a living giant protist and show that these traces bear a remarkable resemblance to the Precambrian trace fossils, including those as old as 1.8 billion years. This is the first evidence that organisms other than multicellular animals can produce such traces, and it prompts re-evaluation of the significance of Precambrian trace fossils as evidence of the early diversification of Bilateria. Our observations also render indirect support to the highly controversial interpretation of the enigmatic Ediacaran biota of the late Precambrian as giant protists.

  19. Iterative sure independence screening EM-Bayesian LASSO algorithm for multi-locus genome-wide association studies.

    PubMed

    Tamba, Cox Lwaka; Ni, Yuan-Li; Zhang, Yuan-Ming

    2017-01-01

    Genome-wide association study (GWAS) entails examining a large number of single nucleotide polymorphisms (SNPs) in a limited sample with hundreds of individuals, implying a variable selection problem in the high dimensional dataset. Although many single-locus GWAS approaches under polygenic background and population structure controls have been widely used, some significant loci fail to be detected. In this study, we used an iterative modified-sure independence screening (ISIS) approach in reducing the number of SNPs to a moderate size. Expectation-Maximization (EM)-Bayesian least absolute shrinkage and selection operator (BLASSO) was used to estimate all the selected SNP effects for true quantitative trait nucleotide (QTN) detection. This method is referred to as ISIS EM-BLASSO algorithm. Monte Carlo simulation studies validated the new method, which has the highest empirical power in QTN detection and the highest accuracy in QTN effect estimation, and it is the fastest, as compared with efficient mixed-model association (EMMA), smoothly clipped absolute deviation (SCAD), fixed and random model circulating probability unification (FarmCPU), and multi-locus random-SNP-effect mixed linear model (mrMLM). To further demonstrate the new method, six flowering time traits in Arabidopsis thaliana were re-analyzed by four methods (New method, EMMA, FarmCPU, and mrMLM). As a result, the new method identified most previously reported genes. Therefore, the new method is a good alternative for multi-locus GWAS.

  20. Iterative sure independence screening EM-Bayesian LASSO algorithm for multi-locus genome-wide association studies

    PubMed Central

    Tamba, Cox Lwaka; Ni, Yuan-Li; Zhang, Yuan-Ming

    2017-01-01

    Genome-wide association study (GWAS) entails examining a large number of single nucleotide polymorphisms (SNPs) in a limited sample with hundreds of individuals, implying a variable selection problem in the high dimensional dataset. Although many single-locus GWAS approaches under polygenic background and population structure controls have been widely used, some significant loci fail to be detected. In this study, we used an iterative modified-sure independence screening (ISIS) approach in reducing the number of SNPs to a moderate size. Expectation-Maximization (EM)-Bayesian least absolute shrinkage and selection operator (BLASSO) was used to estimate all the selected SNP effects for true quantitative trait nucleotide (QTN) detection. This method is referred to as ISIS EM-BLASSO algorithm. Monte Carlo simulation studies validated the new method, which has the highest empirical power in QTN detection and the highest accuracy in QTN effect estimation, and it is the fastest, as compared with efficient mixed-model association (EMMA), smoothly clipped absolute deviation (SCAD), fixed and random model circulating probability unification (FarmCPU), and multi-locus random-SNP-effect mixed linear model (mrMLM). To further demonstrate the new method, six flowering time traits in Arabidopsis thaliana were re-analyzed by four methods (New method, EMMA, FarmCPU, and mrMLM). As a result, the new method identified most previously reported genes. Therefore, the new method is a good alternative for multi-locus GWAS. PMID:28141824

  1. Taxonomic evaluation of putative Streptomyces scabiei strains held in the ARS Culture Collection (NRRL) using multi-locus sequence analysis.

    PubMed

    Labeda, David P

    2016-03-01

    Multi-locus sequence analysis has been demonstrated to be a useful tool for identification of Streptomyces species and was previously applied to phylogenetically differentiate the type strains of species pathogenic on potatoes (Solanum tuberosum L.). The ARS Culture Collection (NRRL) contains 43 strains identified as Streptomyces scabiei deposited at various times since the 1950s and these were subjected to multi-locus sequence analysis utilising partial sequences of the house-keeping genes atpD, gyrB, recA, rpoB and trpB. Phylogenetic analyses confirmed the identity of 17 of these strains as Streptomyces scabiei, 9 of the strains as the potato-pathogenic species Streptomyces europaeiscabiei and 6 strains as potentially new phytopathogenic species. Of the 16 other strains, 12 were identified as members of previously described non-pathogenic Streptomyces species while the remaining 4 strains may represent heretofore unrecognised non-pathogenic species. This study demonstrated the value of this technique for the relatively rapid, simple and sensitive molecular identification of Streptomyces strains held in culture collections.

  2. Utility of deep sea CO2 release experiments in understanding the biology of a high-CO2 ocean: Effects of hypercapnia on deep sea meiofauna

    NASA Astrophysics Data System (ADS)

    Barry, James P.; Buck, Kurt R.; Lovera, Chris; Kuhnz, Linda; Whaling, Patrick J.

    2005-09-01

    Oceanic CO2 levels are expected to rise during the next 2 centuries to levels not seen for 10-150 million years by the uptake of atmospheric CO2 in surface waters or potentially through the disposal of waste CO2 in the deep sea. Changes in ocean chemistry caused by CO2 influx may have broad impacts on ocean ecosystems. Physiological processes animals use to cope with CO2-related stress are known, but the range of sensitivities and effects of changes in ocean chemistry on most ocean life remain unclear. We evaluate the effectiveness of various designs for in situ CO2 release experiments in producing stable perturbations in seawater chemistry over experimental seafloor plots, as is desirable for evaluating the CO2 sensitivities of deep sea animals. We also discuss results from a subset of these experiments on the impacts of hypercapnia on deep sea meiofauna, in the context of experimental designs. Five experiments off central California show that pH perturbations were greatest for experiments using "point source" CO2 pools surrounded by experimental plots. CO2 enclosure experiments with experimental plots positioned within a circular arrangement of CO2 pools had more moderate pH variation. The concentration of dissolution plumes from CO2 pools were related to the speed and turbulence of near-bottom currents, which influence CO2 dissolution and advection. Survival of meiofauna (nematodes, amoebae, euglenoid flagellates) was low after episodic severe hypercapnia but lower and variable where pH changes ranged from 0 to 0.2 pH units below normal.

  3. Photographic observations of the life style of a deep-sea ophiuroid Asteronyx loveni (Echinodermata)

    NASA Astrophysics Data System (ADS)

    Fujita, Toshihiko; Ohta, Suguru

    1988-12-01

    The life style of a deep-sea ophiuroid, Asteronyx loveni was studied from underwater photographs (7 stations) and trawled samples (11 stations) between about 800 and 1700 m along the Pacific coast of Japan and in the Flores Sea, Indonesia. This ophiuroid typically clings to gorgonians ( Radicipes spp.) and pennatulids ( Funiculina quadrangularis and Anthoptilum sp.). The stomach contents of A. loveni included fragments of crustaceans, polychaete setae, sediment particles and flocculent material, but no tissues of the host coelenterates. Bottom photographs show the ophiuroids extending several arms into the water column presumably for suspension feeding. There was rarely more than one ophiuroid per coelenterate host, perhaps due to intraspecific competition for perch sites. Stereoscopic analysis of photographs revealed that most of the ophiuroids perched 20-35 cm above the sea floor. This may be the most effective height for feeding on particulate material resuspended from the sea floor by bottom currents.

  4. Deep-Sea Field Studies of the Biological Consequences of Direct Ocean CO2 Sequestration

    NASA Astrophysics Data System (ADS)

    Barry, J. P.; Seibel, B. A.; Lovera, C.

    2001-12-01

    While the notion of carbon sequestration by direct ocean disposal of CO2 in the deep ocean holds promise for mitigating atmospheric greenhouse warming, the consequences of this approach for deep-sea ecosystems are understood poorly, but are potentially large. Several factors suggest that deep-sea fauna may be more sensitive to deep-sea CO2 releases than related groups inhabiting the upper ocean. The evolution of deep-sea species in the relatively invariant environment of the deep ocean has likely led to the intolerance of many species to perturbations in seawater chemistry associated with direct CO2 injection (e.g. pH reduction) that may be more tolerable to shallow-living groups. Food limitation and reduced metabolic rates typical in deep-sea ecosystems may also limit the ability of many organisms to tolerate changes in pH (i.e. pH compensation) or CO2 (e.g. metabolic depression). We recently performed field experiments at depths from 3000 to 3600 m to evaluate the biological responses of representative deep-sea organisms to changes in seawater chemistry caused by carbon dioxide sequestration. Several small pools (ca. 15 l) of liquid CO2 were deployed on the seafloor from the ROV Tiburon operated by the Monterey Bay Aquarium Research Institute, using a novel CO2 release system. Rates of survival and aspects of the physiological condition of various elements of the seafloor faunal community were compared between sites near (<1 m) and distant (control sites >30 m away) from CO2 pools. Tidally oscillating currents swept a plume of CO2-rich water away from the pools as the liquid CO2 dissolved, resulting in periodic reductions of pH around the pools to 6.0 to 7.0 units within 1 m. Rates of survival for two common megafaunal echinoderms (echinoid 1 and holothurian 1) held in cages adjacent to CO2 pools were very low compared were compared to control sites. Decalcification of urchin spines and skeletal elements was evident for animals near CO2 pools. The abundances of

  5. Genomic characterization of symbiotic mycoplasmas from the stomach of deep-sea isopod bathynomus sp.

    PubMed

    Wang, Yong; Huang, Jiao-Mei; Wang, Shao-Lu; Gao, Zhao-Ming; Zhang, Ai-Qun; Danchin, Antoine; He, Li-Sheng

    2016-09-01

    Deep-sea isopod scavengers such as Bathynomus sp. are able to live in nutrient-poor environments, which is likely attributable to the presence of symbiotic microbes in their stomach. In this study we recovered two draft genomes of mycoplasmas, Bg1 and Bg2, from the metagenomes of the stomach contents and stomach sac of a Bathynomus sp. sample from the South China Sea (depth of 898 m). Phylogenetic trees revealed a considerable genetic distance to other mycoplasma species for Bg1 and Bg2. Compared with terrestrial symbiotic mycoplasmas, the Bg1 and Bg2 genomes were enriched with genes encoding phosphoenolpyruvate-dependent phosphotransferase systems (PTSs) and sodium-driven symporters responsible for the uptake of sugars, amino acids and other carbohydrates. The genome of mycoplasma Bg1 contained sialic acid lyase and transporter genes, potentially enabling the bacteria to attach to the stomach sac and obtain organic carbons from various cell walls. Both of the mycoplasma genomes contained multiple copies of genes related to proteolysis and oligosaccharide degradation, which may help the host survive in low-nutrient conditions. The discovery of the different types of mycoplasma bacteria in the stomach of this deep-sea isopod affords insights into symbiotic model of deep-sea animals and genomic plasticity of mycoplasma bacteria.

  6. Prokaryote diversity and viral production in deep-sea sediments and seamounts

    NASA Astrophysics Data System (ADS)

    Danovaro, Roberto; Corinaldesi, Cinzia; Luna, Gian Marco; Magagnini, Mirko; Manini, Elena; Pusceddu, Antonio

    2009-05-01

    Despite the fact that marine prokaryotes and viruses have been increasingly investigated over the last decade, knowledge on prokaryote diversity and viral production in bathyal sediments is limited. We investigated microbial variables in the deep-sea sediments around two seamounts at 3000-m depth in the Tyrrhenian Sea and sediments located at the same depth, but not affected by the presence of the seamounts. We hypothesized that seamounts altered significantly prokaryotes-viruses interactions in surrounding deep-sea sediments. Sediments surrounding seamounts were characterised by prokaryotic abundances significantly higher than those observed in non-seamount sediments. Benthic viral production was about double in sediments close to seamounts than in non-seamount sediments, where virus turnover was up to 3 times lower. Total Bacteria, as assessed by CARD-FISH, dominated prokaryotic community structure, whereas Archaea accounted on average for approximately 10%. The fraction of Crenarchaeota was always higher than Euryarchaeota. Bacterial diversity, estimated using ARISA, was high, with up to 127 different microbial operational taxonomic units (OTUs) in a single sample. Archaeal richness (determined using T-RFLP of the 16S rRNA gene) ranged from 12 to 20 OTUs, while Archaeal evenness was comprised between 0.529±0.018 and 0.623±0.08. Results represent a pointer for future investigations dealing with the interactions between viruses and prokaryotes in deep-sea sediments.

  7. Seafloor heterogeneity influences the biodiversity–ecosystem functioning relationships in the deep sea

    PubMed Central

    Zeppilli, Daniela; Pusceddu, Antonio; Trincardi, Fabio; Danovaro, Roberto

    2016-01-01

    Theoretical ecology predicts that heterogeneous habitats allow more species to co-exist in a given area. In the deep sea, biodiversity is positively linked with ecosystem functioning, suggesting that deep-seabed heterogeneity could influence ecosystem functions and the relationships between biodiversity and ecosystem functioning (BEF). To shed light on the BEF relationships in a heterogeneous deep seabed, we investigated variations in meiofaunal biodiversity, biomass and ecosystem efficiency within and among different seabed morphologies (e.g., furrows, erosional troughs, sediment waves and other depositional structures, landslide scars and deposits) in a narrow geo-morphologically articulated sector of the Adriatic Sea. We show that distinct seafloor morphologies are characterized by highly diverse nematode assemblages, whereas areas sharing similar seabed morphologies host similar nematode assemblages. BEF relationships are consistently positive across the entire region, but different seabed morphologies are characterised by different slope coefficients of the relationship. Our results suggest that seafloor heterogeneity, allowing diversified assemblages across different habitats, increases diversity and influence ecosystem processes at the regional scale, and BEF relationships at smaller spatial scales. We conclude that high-resolution seabed mapping and a detailed analysis of the species distribution at the habitat scale are crucial for improving management of goods and services delivered by deep-sea ecosystems. PMID:27211908

  8. Gulf of Mexico Deep-Sea Coral Ecosystem Studies, 2008-2011

    USGS Publications Warehouse

    Kellogg, Christina A.

    2009-01-01

    Most people are familiar with tropical coral reefs, located in warm, well-illuminated, shallow waters. However, corals also exist hundreds and even thousands of meters below the ocean surface, where it is cold and completely dark. These deep-sea corals, also known as cold-water corals, have become a topic of interest due to conservation concerns over the impacts of trawling, exploration for oil and gas, and climate change. Although the existence of these corals has been known since the 1800s, our understanding of their distribution, ecology, and biology is limited due to the technical difficulties of conducting deep-sea research. DISCOVRE (DIversity, Systematics, and COnnectivity of Vulnerable Reef Ecosystems) is a new U.S. Geological Survey (USGS) program focused on deep-water coral ecosystems in the Gulf of Mexico. This integrated, multidisciplinary, international effort investigates a variety of topics related to unique and fragile deep-sea coral ecosystems from the microscopic level to the ecosystem level, including components of microbiology, population genetics, paleoecology, food webs, taxonomy, community ecology, physical oceanography, and mapping.

  9. Starvation and recovery in the deep-sea methanotroph Methyloprofundus sedimenti.

    PubMed

    Tavormina, Patricia L; Kellermann, Matthias Y; Antony, Chakkiath Paul; Tocheva, Elitza I; Dalleska, Nathan F; Jensen, Ashley J; Valentine, David L; Hinrichs, Kai-Uwe; Jensen, Grant J; Dubilier, Nicole; Orphan, Victoria J

    2017-01-01

    In the deep ocean, the conversion of methane into derived carbon and energy drives the establishment of diverse faunal communities. Yet specific biological mechanisms underlying the introduction of methane-derived carbon into the food web remain poorly described, due to a lack of cultured representative deep-sea methanotrophic prokaryotes. Here, the response of the deep-sea aerobic methanotroph Methyloprofundus sedimenti to methane starvation and recovery was characterized. By combining lipid analysis, RNA analysis, and electron cryotomography, it was shown that M. sedimenti undergoes discrete cellular shifts in response to methane starvation, including changes in headgroup-specific fatty acid saturation levels, and reductions in cytoplasmic storage granules. Methane starvation is associated with a significant increase in the abundance of gene transcripts pertinent to methane oxidation. Methane reintroduction to starved cells stimulates a rapid, transient extracellular accumulation of methanol, revealing a way in which methane-derived carbon may be routed to community members. This study provides new understanding of methanotrophic responses to methane starvation and recovery, and lays the initial groundwork to develop Methyloprofundus as a model chemosynthesizing bacterium from the deep sea.

  10. Seafloor heterogeneity influences the biodiversity–ecosystem functioning relationships in the deep sea

    NASA Astrophysics Data System (ADS)

    Zeppilli, Daniela; Pusceddu, Antonio; Trincardi, Fabio; Danovaro, Roberto

    2016-05-01

    Theoretical ecology predicts that heterogeneous habitats allow more species to co-exist in a given area. In the deep sea, biodiversity is positively linked with ecosystem functioning, suggesting that deep-seabed heterogeneity could influence ecosystem functions and the relationships between biodiversity and ecosystem functioning (BEF). To shed light on the BEF relationships in a heterogeneous deep seabed, we investigated variations in meiofaunal biodiversity, biomass and ecosystem efficiency within and among different seabed morphologies (e.g., furrows, erosional troughs, sediment waves and other depositional structures, landslide scars and deposits) in a narrow geo-morphologically articulated sector of the Adriatic Sea. We show that distinct seafloor morphologies are characterized by highly diverse nematode assemblages, whereas areas sharing similar seabed morphologies host similar nematode assemblages. BEF relationships are consistently positive across the entire region, but different seabed morphologies are characterised by different slope coefficients of the relationship. Our results suggest that seafloor heterogeneity, allowing diversified assemblages across different habitats, increases diversity and influence ecosystem processes at the regional scale, and BEF relationships at smaller spatial scales. We conclude that high-resolution seabed mapping and a detailed analysis of the species distribution at the habitat scale are crucial for improving management of goods and services delivered by deep-sea ecosystems.

  11. Dense water plumes modulate richness and productivity of deep sea microbes.

    PubMed

    Luna, Gian Marco; Chiggiato, Jacopo; Quero, Grazia Marina; Schroeder, Katrin; Bongiorni, Lucia; Kalenitchenko, Dimitri; Galand, Pierre E

    2016-12-01

    Growing evidence indicates that dense water formation and flow over the continental shelf is a globally relevant oceanographic process, potentially affecting microbial assemblages down to the deep ocean. However, the extent and consequences of this influence have yet to be investigated. Here it is shown that dense water propagation to the deep ocean increases the abundance of prokaryotic plankton, and stimulates carbon production and organic matter degradation rates. Dense waters spilling off the shelf modifies community composition of deep sea microbial assemblages, leading to the increased relevance of taxa likely originating from the sea surface and the seafloor. This phenomenon can be explained by a combination of factors that interplay during the dense waters propagation, such as the transport of surface microbes to the ocean floor (delivering in our site 0.1 megatons of C), the stimulation of microbial metabolism due to increased ventilation and nutrients availability, the sediment re-suspension, and the mixing with ambient waters along the path. Thus, these results highlight a hitherto unidentified role for dense currents flowing over continental shelves in influencing deep sea microbes. In light of climate projections, this process will affect significantly the microbial functioning and biogeochemical cycling of large sectors of the ocean interior.

  12. Evidence of a Putative Deep Sea Specific Microbiome in Marine Sponges

    PubMed Central

    Kennedy, Jonathan; Flemer, Burkhardt; Jackson, Stephen A.; Morrissey, John P.; O'Gara, Ferghal; Dobson, Alan D. W.

    2014-01-01

    The microbiota of four individual deep water sponges, Lissodendoryx diversichela, Poecillastra compressa, Inflatella pellicula, and Stelletta normani, together with surrounding seawater were analysed by pyrosequencing of a region of the 16S rRNA gene common to Bacteria and Archaea. Due to sampling constraints at depths below 700 m duplicate samples were not collected. The microbial communities of L. diversichela, P. compressa and I. pellicula were typical of low microbial abundance (LMA) sponges while S. normani had a community more typical of high microbial abundance (HMA) sponges. Analysis of the deep sea sponge microbiota revealed that the three LMA-like sponges shared a set of abundant OTUs that were distinct from those associated with sponges from shallow waters. Comparison of the pyrosequencing data with that from shallow water sponges revealed that the microbial communities of all sponges analysed have similar archaeal populations but that the bacterial populations of the deep sea sponges were distinct. Further analysis of the common and abundant OTUs from the three LMA-like sponges placed them within the groups of ammonia oxidising Archaea (Thaumarchaeota) and sulphur oxidising γ-Proteobacteria (Chromatiales). Reads from these two groups made up over 70% of all 16S rRNA genes detected from the three LMA-like sponge samples, providing evidence of a putative common microbial assemblage associated with deep sea LMA sponges. PMID:24670421

  13. Evidence of a putative deep sea specific microbiome in marine sponges.

    PubMed

    Kennedy, Jonathan; Flemer, Burkhardt; Jackson, Stephen A; Morrissey, John P; O'Gara, Fergal; O'Gara, Ferghal; Dobson, Alan D W

    2014-01-01

    The microbiota of four individual deep water sponges, Lissodendoryx diversichela, Poecillastra compressa, Inflatella pellicula, and Stelletta normani, together with surrounding seawater were analysed by pyrosequencing of a region of the 16S rRNA gene common to Bacteria and Archaea. Due to sampling constraints at depths below 700 m duplicate samples were not collected. The microbial communities of L. diversichela, P. compressa and I. pellicula were typical of low microbial abundance (LMA) sponges while S. normani had a community more typical of high microbial abundance (HMA) sponges. Analysis of the deep sea sponge microbiota revealed that the three LMA-like sponges shared a set of abundant OTUs that were distinct from those associated with sponges from shallow waters. Comparison of the pyrosequencing data with that from shallow water sponges revealed that the microbial communities of all sponges analysed have similar archaeal populations but that the bacterial populations of the deep sea sponges were distinct. Further analysis of the common and abundant OTUs from the three LMA-like sponges placed them within the groups of ammonia oxidising Archaea (Thaumarchaeota) and sulphur oxidising γ-Proteobacteria (Chromatiales). Reads from these two groups made up over 70% of all 16S rRNA genes detected from the three LMA-like sponge samples, providing evidence of a putative common microbial assemblage associated with deep sea LMA sponges.

  14. Seafloor heterogeneity influences the biodiversity-ecosystem functioning relationships in the deep sea.

    PubMed

    Zeppilli, Daniela; Pusceddu, Antonio; Trincardi, Fabio; Danovaro, Roberto

    2016-05-23

    Theoretical ecology predicts that heterogeneous habitats allow more species to co-exist in a given area. In the deep sea, biodiversity is positively linked with ecosystem functioning, suggesting that deep-seabed heterogeneity could influence ecosystem functions and the relationships between biodiversity and ecosystem functioning (BEF). To shed light on the BEF relationships in a heterogeneous deep seabed, we investigated variations in meiofaunal biodiversity, biomass and ecosystem efficiency within and among different seabed morphologies (e.g., furrows, erosional troughs, sediment waves and other depositional structures, landslide scars and deposits) in a narrow geo-morphologically articulated sector of the Adriatic Sea. We show that distinct seafloor morphologies are characterized by highly diverse nematode assemblages, whereas areas sharing similar seabed morphologies host similar nematode assemblages. BEF relationships are consistently positive across the entire region, but different seabed morphologies are characterised by different slope coefficients of the relationship. Our results suggest that seafloor heterogeneity, allowing diversified assemblages across different habitats, increases diversity and influence ecosystem processes at the regional scale, and BEF relationships at smaller spatial scales. We conclude that high-resolution seabed mapping and a detailed analysis of the species distribution at the habitat scale are crucial for improving management of goods and services delivered by deep-sea ecosystems.

  15. High Acidification Rate of Norwegian Sea Revealed by Boron Isotopes in the Deep-Sea Coral Madrepora Oculata

    NASA Astrophysics Data System (ADS)

    Gonzalez, C.; Douville, E.; Hall-Spencer, J.; Montagna, P.; Louvat, P.; Gaillardet, J.; Frank, N.; Bordier, L.; Juillet-Leclerc, A.

    2012-12-01

    Ocean acidification and global warming due to the increase of anthropogenic CO2 are major threats for marine calcifying organisms, such as deep-sea corals, particularly in high-latitude regions. In order to evaluate the current anthropogenic perturbation and to properly assess the impacts and responses of calcifiers to previous changes in pH it is critical to investigate past changes of the seawater carbonate system. Unfortunately, current instrumental records of oceanic pH are limited, covering only a few decades. Scleractinian coral skeletons record chemical parameters of the seawater in which they grow. However, pH variability over multidecadal timescales remains largely unknown in intermediate and deep seawater masses. Here we present a study that highlights the potential of deep-sea-corals to overcome the lack of long-term pH records and that emphasizes a rapid acidification of high latitude subsurface waters of Norwegian Sea during the past decades. We have reconstructed seawater pH and temperature from a well dated deep-sea coral specimen Madrepora oculata collected alive from Røst reef in Norwegian Sea (67°N, 9°E, 340 m depth). This large branching framework forming coral species grew its skeleton over more than four decades determined using AMS 14C and 210Pb dating (Sabatier et al. 2012). B-isotopes and Li/Mg ratios yield an acidification rate of about -0.0030±0.0008 pH-unit.year-1 and a warming of 0.3°C during the past four decades (1967-2007). Overall our reconstruction technique agrees well with previous pH calculations (Hönisch et al., 2007 vs. Trotter et al., 2011 and McCulloch et al., 2012, i.e. the iterative method), but additional corrections are here applied using stable isotope correlations (O, C, B) to properly address kinetic fractionation of boron isotopes used for pH reconstruction. The resulting pH curve strongly anti-correlates with the annual NAO index, which further strengthens our evidence for the ocean acidification rate

  16. Bacterial diversity in the South Adriatic Sea during a strong, deep winter convection year.

    PubMed

    Korlević, M; Pop Ristova, P; Garić, R; Amann, R; Orlić, S

    2015-03-01

    The South Adriatic Sea is the deepest part of the Adriatic Sea and represents a key area for both the Adriatic Sea and the deep eastern Mediterranean. It has a role in dense water formation for the eastern Mediterranean deep circulation cell, and it represents an entry point for water masses originating from the Ionian Sea. The biodiversity and seasonality of bacterial picoplankton before, during, and after deep winter convection in the oligotrophic South Adriatic waters were assessed by combining comparative 16S rRNA sequence analysis and catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). The picoplankton communities reached their maximum abundance in the spring euphotic zone when the maximum value of the chlorophyll a in response to deep winter convection was recorded. The communities were dominated by Bacteria, while Archaea were a minor constituent. A seasonality of bacterial richness and diversity was observed, with minimum values occurring during the winter convection and spring postconvection periods and maximum values occurring under summer stratified conditions. The SAR11 clade was the main constituent of the bacterial communities and reached the maximum abundance in the euphotic zone in spring after the convection episode. Cyanobacteria were the second most abundant group, and their abundance strongly depended on the convection event, when minimal cyanobacterial abundance was observed. In spring and autumn, the euphotic zone was characterized by Bacteroidetes and Gammaproteobacteria. Bacteroidetes clades NS2b, NS4, and NS5 and the gammaproteobacterial SAR86 clade were detected to co-occur with phytoplankton blooms. The SAR324, SAR202, and SAR406 clades were present in the deep layer, exhibiting different seasonal variations in abundance. Overall, our data demonstrate that the abundances of particular bacterial clades and the overall bacterial richness and diversity are greatly impacted by strong winter convection.

  17. Bacterial Diversity in the South Adriatic Sea during a Strong, Deep Winter Convection Year

    PubMed Central

    Korlević, M.; Pop Ristova, P.; Garić, R.; Amann, R.

    2014-01-01

    The South Adriatic Sea is the deepest part of the Adriatic Sea and represents a key area for both the Adriatic Sea and the deep eastern Mediterranean. It has a role in dense water formation for the eastern Mediterranean deep circulation cell, and it represents an entry point for water masses originating from the Ionian Sea. The biodiversity and seasonality of bacterial picoplankton before, during, and after deep winter convection in the oligotrophic South Adriatic waters were assessed by combining comparative 16S rRNA sequence analysis and catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). The picoplankton communities reached their maximum abundance in the spring euphotic zone when the maximum value of the chlorophyll a in response to deep winter convection was recorded. The communities were dominated by Bacteria, while Archaea were a minor constituent. A seasonality of bacterial richness and diversity was observed, with minimum values occurring during the winter convection and spring postconvection periods and maximum values occurring under summer stratified conditions. The SAR11 clade was the main constituent of the bacterial communities and reached the maximum abundance in the euphotic zone in spring after the convection episode. Cyanobacteria were the second most abundant group, and their abundance strongly depended on the convection event, when minimal cyanobacterial abundance was observed. In spring and autumn, the euphotic zone was characterized by Bacteroidetes and Gammaproteobacteria. Bacteroidetes clades NS2b, NS4, and NS5 and the gammaproteobacterial SAR86 clade were detected to co-occur with phytoplankton blooms. The SAR324, SAR202, and SAR406 clades were present in the deep layer, exhibiting different seasonal variations in abundance. Overall, our data demonstrate that the abundances of particular bacterial clades and the overall bacterial richness and diversity are greatly impacted by strong winter convection. PMID:25548042

  18. How can we identify and communicate the ecological value of deep-sea ecosystem services?

    PubMed

    Jobstvogt, Niels; Townsend, Michael; Witte, Ursula; Hanley, Nick

    2014-01-01

    Submarine canyons are considered biodiversity hotspots which have been identified for their important roles in connecting the deep sea with shallower waters. To date, a huge gap exists between the high importance that scientists associate with deep-sea ecosystem services and the communication of this knowledge to decision makers and to the wider public, who remain largely ignorant of the importance of these services. The connectivity and complexity of marine ecosystems makes knowledge transfer very challenging, and new communication tools are necessary to increase understanding of ecological values beyond the science community. We show how the Ecosystem Principles Approach, a method that explains the importance of ocean processes via easily understandable ecological principles, might overcome this challenge for deep-sea ecosystem services. Scientists were asked to help develop a list of clear and concise ecosystem principles for the functioning of submarine canyons through a Delphi process to facilitate future transfers of ecological knowledge. These ecosystem principles describe ecosystem processes, link such processes to ecosystem services, and provide spatial and temporal information on the connectivity between deep and shallow waters. They also elucidate unique characteristics of submarine canyons. Our Ecosystem Principles Approach was successful in integrating ecological information into the ecosystem services assessment process. It therefore has a high potential to be the next step towards a wider implementation of ecological values in marine planning. We believe that successful communication of ecological knowledge is the key to a wider public support for ocean conservation, and that this endeavour has to be driven by scientists in their own interest as major deep-sea stakeholders.

  19. How Can We Identify and Communicate the Ecological Value of Deep-Sea Ecosystem Services?

    PubMed Central

    Jobstvogt, Niels; Townsend, Michael; Witte, Ursula; Hanley, Nick

    2014-01-01

    Submarine canyons are considered biodiversity hotspots which have been identified for their important roles in connecting the deep sea with shallower waters. To date, a huge gap exists between the high importance that scientists associate with deep-sea ecosystem services and the communication of this knowledge to decision makers and to the wider public, who remain largely ignorant of the importance of these services. The connectivity and complexity of marine ecosystems makes knowledge transfer very challenging, and new communication tools are necessary to increase understanding of ecological values beyond the science community. We show how the Ecosystem Principles Approach, a method that explains the importance of ocean processes via easily understandable ecological principles, might overcome this challenge for deep-sea ecosystem services. Scientists were asked to help develop a list of clear and concise ecosystem principles for the functioning of submarine canyons through a Delphi process to facilitate future transfers of ecological knowledge. These ecosystem principles describe ecosystem processes, link such processes to ecosystem services, and provide spatial and temporal information on the connectivity between deep and shallow waters. They also elucidate unique characteristics of submarine canyons. Our Ecosystem Principles Approach was successful in integrating ecological information into the ecosystem services assessment process. It therefore has a high potential to be the next step towards a wider implementation of ecological values in marine planning. We believe that successful communication of ecological knowledge is the key to a wider public support for ocean conservation, and that this endeavour has to be driven by scientists in their own interest as major deep-sea stakeholders. PMID:25055119

  20. Deep under the sea: unraveling the evolutionary history of the deep-sea squat lobster Paramunida (Decapoda, Munididae).

    PubMed

    Cabezas, Patricia; Sanmartín, Isabel; Paulay, Gustav; Macpherson, Enrique; Machordom, Annie

    2012-06-01

    The diversification of Indo-Pacific marine fauna has long captivated the attention of evolutionary biologists. Previous studies have mainly focused on coral reef or shallow water-associated taxa. Here, we present the first attempt to reconstruct the evolutionary history--phylogeny, diversification, and biogeography--of a deep-water lineage. We sequenced the molecular markers 16S, COI, ND1, 18S, and 28S for nearly 80% of the nominal species of the squat lobster genus Paramunida. Analyses of the molecular phylogeny revealed an accelerated diversification in the late Oligocene-Miocene followed by a slowdown in the rate of lineage accumulation over time. A parametric biogeographical reconstruction showed the importance of the southwest Pacific area, specifically the island arc of Fiji, Tonga, Vanuatu, Wallis, and Futuna, for diversification of squat lobsters, probably associated with the global warming, high tectonic activity, and changes in oceanic currents that took place in this region during the Oligocene-Miocene period. These results add strong evidence to the hypothesis that the Neogene was a period of major diversification for marine organisms in both shallow and deep waters.

  1. Development of a genetic system for the deep-sea psychrophilic bacterium Pseudoalteromonas sp. SM9913

    PubMed Central

    2014-01-01

    Background Pseudoalteromonas species are a group of marine gammaproteobacteria frequently found in deep-sea sediments, which may play important roles in deep-sea sediment ecosystem. Although genome sequence analysis of Pseudoalteromonas has revealed some specific features associated with adaptation to the extreme deep-sea environment, it is still difficult to study how Pseudoalteromonas adapt to the deep-sea environment due to the lack of a genetic manipulation system. The aim of this study is to develop a genetic system in the deep-sea sedimentary bacterium Pseudoalteromonas sp. SM9913, making it possible to perform gene mutation by homologous recombination. Results The sensitivity of Pseudoalteromonas sp. SM9913 to antibiotic was investigated and the erythromycin resistance gene was chosen as the selective marker. A shuttle vector pOriT-4Em was constructed and transferred into Pseudoalteromonas sp. SM9913 through intergeneric conjugation with an efficiency of 1.8 × 10-3, which is high enough to perform the gene knockout assay. A suicide vector pMT was constructed using pOriT-4Em as the bone vector and sacB gene as the counterselective marker. The epsT gene encoding the UDP-glucose lipid carrier transferase was selected as the target gene for inactivation by in-frame deletion. The epsT was in-frame deleted using a two-step integration–segregation strategy after transferring the suicide vector pMT into Pseudoalteromonas sp. SM9913. The ΔepsT mutant showed approximately 73% decrease in the yield of exopolysaccharides, indicating that epsT is an important gene involved in the EPS production of SM9913. Conclusions A conjugal transfer system was constructed in Pseudoalteromonas sp. SM9913 with a wide temperature range for selection and a high transfer efficiency, which will lay the foundation of genetic manipulation in this strain. The epsT gene of SM9913 was successfully deleted with no selective marker left in the chromosome of the host, which thus make it

  2. The economic implications of changing regulations for deep sea fishing under the European Common Fisheries Policy: UK case study.

    PubMed

    Mangi, Stephen C; Kenny, Andrew; Readdy, Lisa; Posen, Paulette; Ribeiro-Santos, Ana; Neat, Francis C; Burns, Finlay

    2016-08-15

    Economic impact assessment methodology was applied to UK fisheries data to better understand the implications of European Commission proposal for regulations to fishing for deep-sea stocks in the North-East Atlantic (EC COM 371 Final 2012) under the Common Fisheries Policy (CFP). The aim was to inform the on-going debate to develop the EC proposal, and to assist the UK fishing industry and Government in evaluating the most effective options to manage deep sea fish stocks. Results indicate that enforcing the EC proposal as originally drafted results in a number of implications for the UK fleet. Because of the proposed changes to the list of species defined as being deep sea species, and a new definition of what constitutes a vessel targeting deep sea species, a total of 695 active UK fishing vessels would need a permit to fish for deep sea species. However, due to existing and capped capacity limits many vessels would potentially not be able to obtain such a permit. The economic impact of these changes from the status quo reveals that in the short term, landings would decrease by 6540 tonnes, reducing gross value added by £3.3 million. Alternative options were also assessed that provide mitigation measures to offset the impacts of the proposed regulations whilst at the same time providing more effective protection of deep sea Vulnerable Marine Ecosystems (VMEs). The options include setting a 400m depth rule that identifies a depth beyond which vessels would potentially be classified as fishing for deep sea species and designating 'core areas' for deep sea fishing at depths>400m to minimise the risk of further impacts of bottom fishing gear on deep sea habitats. Applying a 400m depth limit and 'core fishing' area approach deeper than 400m, the impact of the EC proposal would essentially be reduced to zero, that is, on average no vessels (using the status quo capacity baseline) would be impacted by the proposal.

  3. Calibration of fossil scleraxonian Southern Ocean deep-sea corals for U-series dating

    NASA Astrophysics Data System (ADS)

    Gutjahr, M.; Vance, D.; Hoffmann, D.; Hillenbrand, C.; Kuhn, G.

    2008-12-01

    The deep Southern Ocean has been pinpointed as candidate reservoir capable of storing the additional respired carbon that was drawn from the atmosphere during the Last Glacial Maximum compared with the present-day. In this context the determination of deep ocean ventilation ages is a commonly applied tool, potentially identifying radiocarbon depletion in glacial deep water and enhanced ocean stratification. In order to derive deep-sea ventilation ages most studies to date have used either radiocarbon age differences between paired planktic and benthic foraminifera samples or coupled U-Th and radiocarbon dates obtained from aragonitic deep-sea corals. Results from both these approaches are, however, as yet very scarce for the Southern Ocean. We present calendar ages for a set of deep-sea scleraxonian corals from the Marie Byrd Seamounts in the Amundsen Sea sector of the Southern Ocean (~123°W, ~69°S, 2500 m to 1430 m water depth) employing the 230Th/U-dating method. The aim of our study is to evaluate whether these calcitic octocorals can be used for ventilation age determinations. Our corals have significantly lower uranium concentrations than aragonitic deep-sea corals, ranging from 80 to 250 ng/g. Most corals of Holocene age reproduced the present-day seawater 234U/238U. Pre-Holocene corals, however, show a systematic enrichment of 234U, leading to slightly elevated deglacial initial 234U/238U and significantly higher 234U/238U for ~MIS5 sub-samples. These corals also appear to grow very slowly, on the order of only few μm/year, making it essential to sample as little coral material as possible for combined 230Th/U- and radiocarbon dating purposes. One coral, sampled at high-resolution in various sections returned ages that scatter around 10 ka BP and the early deglaciation, though several significantly older ages were obtained as well. The present-day (234U/238U) ACT in different sections of this coral is very homogenous (1.155 ± 0.003) and more or less

  4. Boron isotopes in deep-sea bamboo corals: pH, vital effects and environmental factors

    NASA Astrophysics Data System (ADS)

    Farmer, J. R.; Hoenisch, B.; Hill, T. M.; LaVigne, M.; Robinson, L. F.

    2011-12-01

    Deep-sea corals are an intriguing archive for reconstructing deep-ocean environmental conditions, in particular with regard to anthropogenic climate change and ocean acidification. However, previous research in deep-sea aragonitic scleractinian corals observed heterogeneity in their geochemical composition that greatly exceeded the magnitude of variability expected from environmental conditions. Here we investigate the boron isotopic composition (δ11B) and B/Ca ratios of the calcitic gorgonian bamboo coral Keratoisis sp. (family Isididae) as potential indicators of seawater-pH at depth. Initial results from a specimen collected alive on Little Joe Seamount, CA (2136m depth) show that the δ11B of surface calcite is within the expected range of aqueous borate-δ11B, based on seawater pH, temperature, pressure and salinity. A radial cross section through an ~5 cm thick internode reveals largely homogeneous δ11B. However, in the centermost 0.5 cm of calcite growth adjacent to the axial core of the coral, a ~2% increase in δ11B corresponds with disequilibrium depletions in δ13C and δ18O, consistent with hypotheses for different growth modes of central calcite perhaps as a result of active calcite deposition along the axial core. Aside from this central region, the geochemical homogeneity and good agreement between coral surface δ11B and seawater borate δ11B suggests that bamboo corals may record deep-ocean carbon chemistry and thus pH. The cosmopolitan distribution of Keratoisis sp. in both living and fossil deep-sea coral communities thus potentially presents the opportunity to reconstruct recent and Holocene deep-water pH at high resolution.

  5. Deep coral oases in the South Tyrrhenian Sea.

    PubMed

    Bo, Marzia; Canese, Simonepietro; Spaggiari, Costanza; Pusceddu, Antonio; Bertolino, Marco; Angiolillo, Michela; Giusti, Michela; Loreto, Maria Filomena; Salvati, Eva; Greco, Silvestro; Bavestrello, Giorgio

    2012-01-01

    A Mediterranean "roche du large" ecosystem, represented by four rocky shoals, located a few miles apart on a muddy bottom at 70-130 m depth in the gulf of St. Eufemia (Calabria, South Tyrrhenian Sea), was studied by means of Remotely Operated Vehicle (ROV) photo imaging. The shoals host highly diversified coral communities, mainly composed of arborescent colonies of gorgonians (Callogorgia verticillata, Paramuricea clavata, Paramuricea macrospina, Bebryce mollis, Villogorgia bebrycoides, Corallium rubrum, and Leptogorgia sarmentosa), and antipatharians (Antipathella subpinnata, Antipathes dichotoma and Parantipathes larix). The coral colonies reach high densities (up to ca. 17 colonies m(-2)) and large sizes, such as the over 1.5 m wide antipatharian colonies. We hypothesized that the abundance and composition of the coral assemblages differed significantly among the rocky shoals and with respect to the surrounding soft bottoms. Various environmental variables were tested as possible explanatory factors of the observed differences. Moreover, due to their off-coast localization, we report here that these unique ecosystems are potentially subjected to a strong pressure from the local fishing activities, which were tentatively characterized. The recorded coral β-diversity among the shoals supports the hypothesis that these habitats behave like small oases of hard substrata interspersed in a muddy bottom. Because of their intrinsic beauty and rarity and their biological and ecological value, we stress the need of specific actions aimed at the urgent protection of these oases of biodiversity.

  6. Sulphur isotopic compositions of deep-sea hydrothermal vent animals

    NASA Technical Reports Server (NTRS)

    Fry, B.; Gest, H.; Hayes, J. M.

    1983-01-01

    The S-34/S-32 ratios of tissues from vestimentiferan worms, brachyuran crabs, and giant clams living around deep hydrothermal vents are reported. Clean tissues were dried, ground, suspended in 0.1 M LiCl, shaken twice at 37 C to remove seawater sulfates, dried at 60 C, combusted in O2 in a Parr bomb. Sulfur was recovered as BaSO4, and the isotopic abundances in SO2 generated by thermal decomposition of 5-30-mg samples were determined using an isotope-ratio mass spectrometer. The results are expressed as delta S-34 and compared with values measured in seawater sulfates and in normal marine fauna. The values ranged from -4.7 to 4.7 per thousand, comparable to vent sulfide minerals (1.3-4.1 per thousand) and distinct from seawater sulfates (20.1 per thousand) and normal marine fauna (about 13-20 per thousand). These results indicate that vent sulfur rather than seawater sulfur is utilized by these animals, a process probably mediated by chemoautotrophic bacteria which can use inorganic sulfur compounds as energy sources.

  7. Deuterium in interstitial water from deep-sea cores

    USGS Publications Warehouse

    Friedman, I.; Hardcastle, K.

    1988-01-01

    As part of the Joint Oceanographic Institutions Deep Earth Sampling project, the interstitial waters of cores from 69 holes were sampled for deuterium analysis to examine changes in the deuterium content of the oceans with time. Changes in the abundance of deuterium can be related to changes in the amount of ice stored in continental glaciers, inasmuch as precipitation in the form of snow is highly depleted in deuterium compared with the oceans. Many of the cores show a change in isotopic composition of samples from early to late Miocene that can be ascribed to the buildup of the Antarctic ice sheets. After correcting for the role of diffusion in reducing the isotopic contrast between samples from a single core, we estimate an incrase of 10 per mil (???) ??D (corresponding to a ??18O change of about 1.2???) between the early and late Miocene. A similar analysis of Pleistocene to Holocene changes indicates a ??D rise of 8??? during the time of maximum continental ice, which corresponds to a ??18O increase of about 1.0???. On the basis of limited data, we find no ??D change in the oceans from Cretaceous to Miocene. -from Authors

  8. Five Hundred and Seventy Three Holes in the Bottom of the Sea-Some Results From Seven Years of Deep-Sea Drilling

    ERIC Educational Resources Information Center

    Davies, T. A.

    1976-01-01

    Described are the background, operation, and findings of the work of the deep sea drilling vessel Glomar Challenger, which has taken 8,638 core samples from 573 holes at 392 sites on the floor of the Earth's oceans. (SL)

  9. The paleoclimatic record provided by eolian deposition in the deep sea: The geologic history of wind

    SciTech Connect

    Rea, D.K.

    1994-05-01

    This article looks at the paleoclimatic record of winds recorded in the deposits of dust grains in the deep sea. Such grains are carried to the sea by the wind. The strength of the wind is indicated by the size of dust grains observed, larger grains requiring stronger winds to effect transport from arid regions. The number of the dust grains provides an indication of the aridity of land masses at the times in question. The record indicates that wind varies on the Milankovitch cycles of orbital variability, but also on time scales shorter than the 100kyr cycles associated with glaciation and aridity.

  10. Distribution of artificial radionuclides in deep sediments of the Mediterranean Sea.

    PubMed

    Garcia-Orellana, J; Pates, J M; Masqué, P; Bruach, J M; Sanchez-Cabeza, J A

    2009-01-01

    Artificial radionuclides enter the Mediterranean Sea mainly through atmospheric deposition following nuclear weapons tests and the Chernobyl accident, but also through the river discharge of nuclear facility effluents. Previous studies of artificial radionuclides impact of the Mediterranean Sea have focussed on shallow, coastal sediments. However, deep sea sediments have the potential to store and accumulate pollutants, including artificial radionuclides. Deep sea marine sediment cores were collected from Mediterranean Sea abyssal plains (depth >2000 m) and analysed for (239,240)Pu and (137)Cs to elucidate the concentrations, inventories and sources of these radionuclides in the deepest areas of the Mediterranean. The activity - depth profiles of (210)Pb, together with (14)C dating, indicate that sediment mixing redistributes the artificial radionuclides within the first 2.5 cm of the sedimentary column. The excess (210)Pb inventory was used to normalize (239,240)Pu and (137)Cs inventories for variable sediment fluxes. The (239,240)Pu/(210)Pb(xs) ratio was uniform across the entire sea, with a mean value of 1.24x10(-3), indicating homogeneous fallout of (239,240)Pu. The (137)Cs/(210)Pb(xs) ratio showed differences between the eastern (0.049) and western basins (0.030), clearly significant impact of deep sea sediments from the Chernobyl accident. The inventory ratios of (239,240)Pu/(137)Cs were 0.041 and 0.025 in the western and eastern basins respectively, greater than the fallout ratio, 0.021, showing more efficient scavenging of (239,240)Pu in the water column and major sedimentation of (137)Cs in the eastern basin. Although areas with water depths of >2000 m constitute around 40% of the entire Mediterranean basin, the sediments in these regions only contained 2.7% of the (239,240)Pu and 0.95% of the (137)Cs deposited across the Sea in 2000. These data show that the accumulation of artificial radionuclides in deep Mediterranean environments is much lower than

  11. Draft genome of bagasse-degrading bacteria Bacillus aryabhattai GZ03 from deep sea water.

    PubMed

    Wen, Jian; Ren, Chong; Huang, Nan; Liu, Yang; Zeng, Runying

    2015-02-01

    Bacillus aryabhattai GZ03 was isolated from deep sea water of the South China Sea, which can produce glucose and fructose by degrading bagasse at 25 °C. Here we report the draft genome sequence of Bacillus aryabhattai GZ03. The data obtained revealed 37 contigs with genome size of 5,105,129 bp and G+C content of 38.09%. The draft genome of B. aryabhattai GZ03 may provide insights into the mechanism of microbial carbohydrate and lignocellulosic material degradation.

  12. Giant larvacean houses: rapid carbon transport to the deep sea floor.

    PubMed

    Robison, Bruce H; Reisenbichler, Kim R; Sherlock, Rob E

    2005-06-10

    An unresolved issue in ocean science is the discrepancy between the food requirements of the animals living on the deep sea floor and their food supply, as measured by sediment traps. A 10-year time-series study of the water column off Monterey Bay, California, revealed that the discarded mucus feeding structures of giant larvaceans carry a substantial portion of the upper ocean's productivity to the deep seabed. These abundant, rapidly sinking, carbon-rich vectors are not detected by conventional sampling methods and thus have not been included in calculations of vertical nutrient flux or in oceanic carbon budgets.

  13. Massive deep-sea sulphide ore deposits discovered on the East Pacific Rise

    USGS Publications Warehouse

    Francheteau, Jean; Needham, H.D.; Choukroune, P.; Juteau, Tierre; Seguret, M.; Ballard, Richard D.; Fox, P.J.; Normark, William; Carranza, A.; Cordoba, D.; Guerrero, J.; Rangin, C.; Bougault, H.; Cambon, P.; Hekinian, R.

    1979-01-01

    Massive ore-grade zinc, copper and iron sulphide deposits have been found at the axis of the East Pacific Rise. Although their presence on the deep ocean-floor had been predicted there was no supporting observational evidence. The East Pacific Rise deposits represent a modern analogue of Cyprus-type sulphide ores associated with ophiolitic rocks on land. They contain at least 29% zinc metal and 6% metallic copper. Their discovery will provide a new focus for deep-sea exploration, leading to new assessments of the concentration of metals in the upper layers of the oceanic crust. ?? 1979 Nature Publishing Group.

  14. Is the extremely rare Iberian endemic plant species Castrilanthemum debeauxii (Compositae, Anthemideae) a 'living fossil'? Evidence from a multi-locus species tree reconstruction.

    PubMed

    Tomasello, Salvatore; Álvarez, Inés; Vargas, Pablo; Oberprieler, Christoph

    2015-01-01

    The present study provides results of multi-species coalescent species tree analyses of DNA sequences sampled from multiple nuclear and plastid regions to infer the phylogenetic relationships among the members of the subtribe Leucanthemopsidinae (Compositae, Anthemideae), to which besides the annual Castrilanthemum debeauxii (Degen, Hervier & É.Rev.) Vogt & Oberp., one of the rarest flowering plant species of the Iberian Peninsula, two other unispecific genera (Hymenostemma, Prolongoa), and the polyploidy complex of the genus Leucanthemopsis belong. Based on sequence information from two single- to low-copy nuclear regions (C16, D35, characterised by Chapman et al. (2007)), the multi-copy region of the nrDNA internal transcribed spacer regions ITS1 and ITS2, and two intergenic spacer regions of the cpDNA gene trees were reconstructed using Bayesian inference methods. For the reconstruction of a multi-locus species tree we applied three different methods: (a) analysis of concatenated sequences using Bayesian inference (MrBayes), (b) a tree reconciliation approach by minimizing the number of deep coalescences (PhyloNet), and (c) a coalescent-based species-tree method in a Bayesian framework ((∗)BEAST). All three species tree reconstruction methods unequivocally support the close relationship of the subtribe with the hitherto unclassified genus Phalacrocarpum, the sister-group relationship of Castrilanthemum with the three remaining genera of the subtribe, and the further sister-group relationship of the clade of Hymenostemma+Prolongoa with a monophyletic genus Leucanthemopsis. Dating of the (∗)BEAST phylogeny supports the long-lasting (Early Miocene, 15-22Ma) taxonomical independence and the switch from the plesiomorphic perennial to the apomorphic annual life-form assumed for the Castrilanthemum lineage that may have occurred not earlier than in the Pliocene (3Ma) when the establishment of a Mediterranean climate with summer droughts triggered evolution towards

  15. Deep Sea Memory of High Atmospheric CO2 Concentration

    NASA Astrophysics Data System (ADS)

    Mathesius, Sabine; Hofmann, Matthias; Caldeira, Ken; Schellnhuber, Hans Joachim

    2015-04-01

    massive CDR interventions eventually bring down the global mean pH value to the RCP2.6 level, yet cannot restore a similarly homogenous distribution - while the pH of the upper ocean returns to the preindustrial value or even exceed it (in the 180 ppm scenario), the deep ocean remains acidified. The deep ocean is out of contact with the atmosphere and therefore unreachable by atmospheric CDR. Our results suggest that the proposition that the marine consequences of early emissions reductions are comparable to those of delayed reductions plus CDR is delusive and that a policy that allows for emitting CO2 today in the hopes of removing it tomorrow is bound to generate substantial regrets.

  16. Population connectivity of deep-sea corals: Chapter 12

    USGS Publications Warehouse

    Morrison, Cheryl L.; Baco, Amy; Nizinski, Martha S.; Coykendall, Dolly K.; Demopoulos, Amanda W. J.; Cho, Walter; Shank, Tim

    2015-01-01

    Identifying the scale of dispersal among habitats has been a challenge in marine ecology for decades (Grantham et al., 2003; Kinlan & Gaines, 2003; Hixon, 2011). Unlike terrestrial habitats in which barriers to dispersal may be obvious (e.g. mountain ranges, rivers), few absolute barriers to dispersal are recognizable in the sea. Additionally, most marine species have complex life cycles in which juveniles are more mobile than adults. As such, the dynamics of populations may involve processes in distant habitats that are coupled by a transport mechanism. Studies of population connectivity try to quantify the transport, or dispersal of individuals, among geographically separated populations. For benthic marine species, such as corals and demersal fishes, colonization of new populations occurs primarily by dispersal of larvae (Figure 1; Shank, 2010). Successful dispersal and recruitment, followed by maturation and reproduction of these new migrants ensures individuals contribute to the gene pool (Hedgecock, 2007). Thus, successful dispersal links and cohesively maintains spatially separated sub-populations. At shorter time scales (10-100s years), connectivity regulates community structure by influencing the genetic composition, diversity and demographic stability of the population, whereas at longer time scales (1000s years), geographic distributions are affected (McClain and Hardy, 2010). Alternatively, populations may become extinct or speciation may occur if connectivity ceases (Cowen et al., 2007). Therefore, the genetic exchange of individuals between populations is fundamental to the short-term resilience and long-term maintenance of the species. However, for the vast majority of marine species, population connectivity remains poorly understood.

  17. NASA light emitting diode medical applications from deep space to deep sea

    NASA Astrophysics Data System (ADS)

    Whelan, Harry T.; Buchmann, Ellen V.; Whelan, Noel T.; Turner, Scott G.; Cevenini, Vita; Stinson, Helen; Ignatius, Ron; Martin, Todd; Cwiklinski, Joan; Meyer, Glenn A.; Hodgson, Brian; Gould, Lisa; Kane, Mary; Chen, Gina; Caviness, James

    2001-02-01

    This work is supported and managed through the NASA Marshall Space Flight Center-SBIR Program. LED-technology developed for NASA plant growth experiments in space shows promise for delivering light deep into tissues of the body to promote wound healing and human tissue growth. We present the results of LED-treatment of cells grown in culture and the effects of LEDs on patients' chronic and acute wounds. LED-technology is also biologically optimal for photodynamic therapy of cancer and we discuss our successes using LEDs in conjunction with light-activated chemotherapeutic drugs. .

  18. Optical variability and pigment biomass in the Sargasso Sea as determined using deep-sea optical mooring data

    NASA Technical Reports Server (NTRS)

    Smith, R. C.; Waters, K. J.; Baker, K. S.

    1991-01-01

    A 9-month time series of optical data, composed of three separate deployments, from the Biowatt 1987 deep-sea mooring located in the oligotrophic waters of the Sargasso Sea at 32 deg N, 70 deg W, is presented. These data were analyzed using several biooptical models for the purpose of providing a continuous estimate of the spectral diffuse attenuation coefficient and pigment biomass. Results of the first 70-day deployment demonstrate the utility of optical observations as proxy measures of biological parameters, and facilitate a preliminary analysis of the temporal variations and a comparison of the present biooptical observations with concurrent physical observations. Biooptical properties exhibit variation in response to physical forcings, such as diel variations of incident solar irradiance, episodic wind forcing, advective mesoscale eddy layer depth, and succession of phytoplankton. The mooring data are discussed in the context of contemporaneous shipboard observations as well as in terms of future ocean satellite observations.

  19. Spontaneous and Widespread Electricity Generation in Natural Deep-Sea Hydrothermal Fields.

    PubMed

    Yamamoto, Masahiro; Nakamura, Ryuhei; Kasaya, Takafumi; Kumagai, Hidenori; Suzuki, Katsuhiko; Takai, Ken

    2017-04-05

    Deep-sea hydrothermal vents discharge abundant reductive energy into oxidative seawater. Herein, we demonstrated that in situ measurements of redox potentials on the surfaces of active hydrothermal mineral deposits were more negative than the surrounding seawater potential, driving electrical current generation. We also demonstrated that negative potentials in the surface of minerals were widespread in the hydrothermal fields, regardless of the proximity to hydrothermal fluid discharges. Lab experiments verified that the negative potential of the mineral surface was induced by a distant electron transfer from the hydrothermal fluid through the metallic and catalytic properties of minerals. These results indicate that electric current is spontaneously and widely generated in natural mineral deposits in deep-sea hydrothermal fields. Our discovery provides important insights into the microbial communities that are supported by extracellular electron transfer and the prebiotic chemical and metabolic evolution of the ocean hydrothermal systems.

  20. Deep seismic survey images crustal structure of Tornquist Zone beneath southern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Meissner, R.; Sadowiak, P.; Thomas, S.; Wever, T.; Dickmann, T.; Flüh, E.; Berthelsen, A.; Thybo, H.; Dahl-Jensen, T.; Balling, N.; Nørmark, E.; Hobbs, R. W.; Klemperer, S. L.; Matthews, D. H.; Snyder, D. B.; Long, R.; Graham, D.; Matthews, T.; Blundell, D. J.; Lund, C.; Palm, H.; Pedersen, L.; Roberts, R.; Elming, S.-E.; Heikkinen, P.; Korhonen, H.; Luosto, U.; Hjelt, S.-E.; Komminaho, K.; Yliniemi, J.

    1991-06-01

    The Tornquist Zone is Europe's longest tectonic lineament and bisects the continent in a NW-SE direction from the North Sea (off NW Denmark) to the Black Sea. New deep seismic reflection and coincident refraction data have been collected across its 50 km wide, intensely faulted and inverted NW part. The marine reflection profile in the area north of Bornholm Island shows a tilted block structure in the rigid upper crust, whereas the lower crust seems to be more gently uplifted. A complex transition from the highly reflective lower crust to the mantle is indicated by mantle reflections and a curious wide-angle event recorded by a landstation on Bornholm Island. We suggest that deep-reaching inversion tectonics, induced by Alpine and Carpathian orogeny, were responsible for the development of the gross crust-mantle structure of the Tornquist Zone in our study area, which seems to be similar to that in Poland.

  1. New Prionospio and Aurospio Species from the Deep Sea (Annelida: Polychaeta).

    PubMed

    Paterson, Gordon L J; Neal, Lenka; Altamira, Iris; Soto, Eulogio H; Smith, Craig R; Menot, Lenaick; Billett, David S M; Cunha, Marina R; Marchais-Laguionie, Claire; Glover, Adrian G

    2016-03-14

    The number of records of the genus Prionospio Malmgren, 1867, from the deep sea (>2000 m) are relatively few and do not reflect the actual occurrence of species nor their potential ecological importance. In this paper we describe five new species of this genus (Prionospio amarsupiata sp. nov., P. vallensis sp. nov., P. branchilucida sp. nov., P. hermesia sp. nov. and P. kaplani sp. nov.) all of which are abundant members of the deep-sea community. We also describe two new species of the genus Aurospio Maciolek, 1981 (Aurospio abranchiata sp. nov. and A. tribranchiata sp. nov.) again common elements of the abyssal fauna. Two of the new species have characters which question the generic distinctiveness of Prionospio and Aurospio. The problems in differentiating these two genera are discussed.

  2. Microbial iron uptake as a mechanism for dispersing iron from deep-sea hydrothermal vents.

    PubMed

    Li, Meng; Toner, Brandy M; Baker, Brett J; Breier, John A; Sheik, Cody S; Dick, Gregory J

    2014-01-01

    Deep-sea hydrothermal vents are a significant source of oceanic iron. Although hydrothermal iron rapidly precipitates as inorganic minerals on mixing with seawater, it can be stabilized by organic matter and dispersed more widely than previously recognized. The nature and source of this organic matter is unknown. Here we show that microbial genes involved in cellular iron uptake are highly expressed in the Guaymas Basin deep-sea hydrothermal plume. The nature of these microbial iron transporters, taken together with the low concentration of dissolved iron and abundance of particulate iron in the plume, indicates that iron minerals are the target for this microbial scavenging and uptake. Our findings indicate that cellular iron uptake is a major process in plume microbial communities and suggest new mechanisms for generating Fe-C complexes. This 'microbial iron pump' could represent an important mode of converting hydrothermal iron into bioavailable forms that can be dispersed throughout the oceans.

  3. First discovery of the organic materials in deep-sea iron cosmic spherule

    NASA Technical Reports Server (NTRS)

    Hanchang, Peng; Peicang, XU

    1993-01-01

    The dust impact mass analyzer (PUMA) carried by the spacecraft Vega 1, Vega 2 and Giotto has provided the first direct measurements of the physical and chemical properties of cometary dust. The results indicate that most of the cometary dust particles are rich in light elements such as H, C, N, and O, suggesting the validity of models that describe the cometary dust as including organic material. Up to now, there were none found with the organic material from the deep-sea cosmic spherules. We have determined this from the deep-sea iron cosmic spherules collected from the North Pacific. An iron cosmic spherule (382 microns in diameter) was determined by the Laser Raman Microprobe.

  4. Estimation of the Iron Loss in Deep-Sea Permanent Magnet Motors considering Seawater Compressive Stress

    PubMed Central

    Wei, Yanyu; Zou, Jibin; Li, Jianjun; Qi, Wenjuan; Li, Yong

    2014-01-01

    Deep-sea permanent magnet motor equipped with fluid compensated pressure-tolerant system is compressed by the high pressure fluid both outside and inside. The induced stress distribution in stator core is significantly different from that in land type motor. Its effect on the magnetic properties of stator core is important for deep-sea motor designers but seldom reported. In this paper, the stress distribution in stator core, regarding the seawater compressive stress, is calculated by 2D finite element method (FEM). The effect of compressive stress on magnetic properties of electrical steel sheet, that is, permeability, BH curves, and BW curves, is also measured. Then, based on the measured magnetic properties and calculated stress distribution, the stator iron loss is estimated by stress-electromagnetics-coupling FEM. At last the estimation is verified by experiment. Both the calculated and measured results show that stator iron loss increases obviously with the seawater compressive stress. PMID:25177717

  5. The giant deep-sea octopus Haliphron atlanticus forages on gelatinous fauna

    PubMed Central

    Hoving, H.J.T.; Haddock, S.H.D.

    2017-01-01

    Feeding strategies and predator-prey interactions of many deep-sea pelagic organisms are still unknown. This is also true for pelagic cephalopods, some of which are very abundant in oceanic ecosystems and which are known for their elaborate behaviors and central role in many foodwebs. We report on the first observations of the giant deep-sea octopus Haliphron atlanticus with prey. Using remotely operated vehicles, we saw these giant octopods holding medusae in their arms. One of the medusae could be identified as Phacellophora camtschatica (the egg-yolk jelly). Stomach content analysis confirmed predation on cnidarians and gelatinous organisms. The relationship between medusae and H. atlanticus is discussed, also in comparison with other species of the Argonautoidea, all of which have close relationships with gelatinous zooplankton. PMID:28344325

  6. Estimation of the iron loss in deep-sea permanent magnet motors considering seawater compressive stress.

    PubMed

    Xu, Yongxiang; Wei, Yanyu; Zou, Jibin; Li, Jianjun; Qi, Wenjuan; Li, Yong

    2014-01-01

    Deep-sea permanent magnet motor equipped with fluid compensated pressure-tolerant system is compressed by the high pressure fluid both outside and inside. The induced stress distribution in stator core is significantly different from that in land type motor. Its effect on the magnetic properties of stator core is important for deep-sea motor designers but seldom reported. In this paper, the stress distribution in stator core, regarding the seawater compressive stress, is calculated by 2D finite element method (FEM). The effect of compressive stress on magnetic properties of electrical steel sheet, that is, permeability, BH curves, and BW curves, is also measured. Then, based on the measured magnetic properties and calculated stress distribution, the stator iron loss is estimated by stress-electromagnetics-coupling FEM. At last the estimation is verified by experiment. Both the calculated and measured results show that stator iron loss increases obviously with the seawater compressive stress.

  7. The giant deep-sea octopus Haliphron atlanticus forages on gelatinous fauna.

    PubMed

    Hoving, H J T; Haddock, S H D

    2017-03-27

    Feeding strategies and predator-prey interactions of many deep-sea pelagic organisms are still unknown. This is also true for pelagic cephalopods, some of which are very abundant in oceanic ecosystems and which are known for their elaborate behaviors and central role in many foodwebs. We report on the first observations of the giant deep-sea octopus Haliphron atlanticus with prey. Using remotely operated vehicles, we saw these giant octopods holding medusae in their arms. One of the medusae could be identified as Phacellophora camtschatica (the egg-yolk jelly). Stomach content analysis confirmed predation on cnidarians and gelatinous organisms. The relationship between medusae and H. atlanticus is discussed, also in comparison with other species of the Argonautoidea, all of which have close relationships with gelatinous zooplankton.

  8. Deep seismic survey images crustal structure of Tornquist Zone beneath southern Baltic Sea

    SciTech Connect

    Not Available

    1991-06-01

    The Tornquist Zone is Europe's longest tectonic lineament and bisects the continent in a NW-SE direction from the North Sea (off NW Denmark) to the Black Sea. New deep seismic reflection and coincident refraction data have been collected across its 50 km wide, intensely faulted and inverted NW part. The marine reflection profile in the area north of Bornholm Island shows a tilted block structure in the rigid upper crust, whereas the lower crust seems to be more gently uplifted. A complex transition from the highly reflective lower crust to the mantle is indicated by mantle reflections and a curious wide-angle event recorded by a landstation on Bornholm Island. The authors suggest that deep-reaching inversion tectonics, induced by Alpine and Carpathian orogeny, were responsible for the development of the gross crust-mantle structure of the Tornquist Zone in the study area, which seems to be similar to that in Poland.

  9. The distribution and composition of deep-sea microbenthos in a bathyal region of the western Coral Sea

    NASA Astrophysics Data System (ADS)

    Alongi, Daniel M.

    1987-07-01

    The distribution and composition of bathyal (298-1610 m) microbenthos were examined on the Queensland continental slope, the Coral Sea Plateau and the adjacent Queensland and Townsville troughs in the western Coral Sea. Two conspicuous changes in community composition were recorded: (1) ciliates were undetected below 700 m and (2) yeasts and yeast-like cells were undetected above 1150 m. Densities of flagellates decreased, whereas amoebae densities increased significantly with water depth. Densities of living Foraminifera ( overlinex = 56 cm-2) increased significantly from the continental slope to the adjacent troughs. Bacterial numbers ranged from 0.1 to 71.0 × 10 8 cells g -1 dry wt of sediment and decreased significantly with water depth. Chlorophyll a (0.0-19.0 μg g -1 dry wt) and phaeopigment (0.0-4.9 μg g -1 dry wt) concentrations suggest that phytodetritus is a major source of organic matter in this tropical region. Concentrations of organic carbon (0.22-0.52%) and nitrogen (<0.01-0.02%) were low compared to most other deep-sea sediments, with a shallow sediment depth distribution indicating little burial of organic matter. These findings, coupled with the presence of abundant protozoan populations (˜10 6 m -2), suggest the potential for rapid microbial activity and dentrital utilization in bathyal surface sediments of the western Coral Sea.

  10. Oxygen and evolutionary patterns in the sea: onshore/offshore trends and recent recruitment of deep-sea faunas

    NASA Technical Reports Server (NTRS)

    Jacobs, D. K.; Lindberg, D. R.

    1998-01-01

    Over the last 15 years a striking pattern of diversification has been documented in the fossil record of benthic marine invertebrates. Higher taxa (orders) tend to originate onshore, diversify offshore, and retreat into deep-water environments. Previous studies attribute this macroevolutionary pattern to a variety of causes, foremost among them the role of nearshore disturbance in providing opportunities for the evolution of novel forms accorded ordinal rank. Our analysis of the post-Paleozoic record of ordinal first appearances indicates that the onshore preference of ordinal origination occurred only in the Mesozoic prior to the Turonian stage of the Cretaceous, a period characterized by relatively frequent anoxic/dysoxic bottom conditions in deeper marine environments. Later, in the Cretaceous and Cenozoic, ordinal origination of benthic organisms did not occur exclusively, or even preferentially, in onshore environments. This change in environmental pattern of ordinal origination roughly correlates with Late Cretaceous: (i) decline in anoxia/dysoxia in offshore benthic environments; (ii) extinction of faunas associated with dysoxic conditions; (iii) increase in bioturbation with the expansion of deep burrowing forms into offshore environments; and (iv) offshore expansion of bryozoan diversity. We also advance a separate argument that the Cenomanian/Turonian and latest Paleocene global events eliminated much of the deep-water benthos. This requires a more recent origin of modern vent and deep-sea faunas, from shallower water refugia, than the Paleozoic or early Mesozoic origin of these faunas suggested by other workers.

  11. Oxygen and evolutionary patterns in the sea: onshore/offshore trends and recent recruitment of deep-sea faunas.

    PubMed

    Jacobs, D K; Lindberg, D R

    1998-08-01

    Over the last 15 years a striking pattern of diversification has been documented in the fossil record of benthic marine invertebrates. Higher taxa (orders) tend to originate onshore, diversify offshore, and retreat into deep-water environments. Previous studies attribute this macroevolutionary pattern to a variety of causes, foremost among them the role of nearshore disturbance in providing opportunities for the evolution of novel forms accorded ordinal rank. Our analysis of the post-Paleozoic record of ordinal first appearances indicates that the onshore preference of ordinal origination occurred only in the Mesozoic prior to the Turonian stage of the Cretaceous, a period characterized by relatively frequent anoxic/dysoxic bottom conditions in deeper marine environments. Later, in the Cretaceous and Cenozoic, ordinal origination of benthic organisms did not occur exclusively, or even preferentially, in onshore environments. This change in environmental pattern of ordinal origination roughly correlates with Late Cretaceous: (i) decline in anoxia/dysoxia in offshore benthic environments; (ii) extinction of faunas associated with dysoxic conditions; (iii) increase in bioturbation with the expansion of deep burrowing forms into offshore environments; and (iv) offshore expansion of bryozoan diversity. We also advance a separate argument that the Cenomanian/Turonian and latest Paleocene global events eliminated much of the deep-water benthos. This requires a more recent origin of modern vent and deep-sea faunas, from shallower water refugia, than the Paleozoic or early Mesozoic origin of these faunas suggested by other workers.

  12. The mortality and morbidity of deep sea fishermen sailing from Grimsby in one year1

    PubMed Central

    Moore, S. R. W.

    1969-01-01

    Moore, S. R. W. (1969).Brit. J. industr. Med.,26, 25-46. The mortality and morbidity of deep sea fishermen sailing from Grimsby in one year. The injuries, illnesses, and deaths of Grimsby deep sea fishermen in the year 1963 have been studied using the trawler log-book as the basic source of information. Additional information has been obtained from other sources. The numbers of man-days sailed by Grimsby deep sea fishermen, by age and rating in 1963, have been ascertained. From these, incapacity rates for the measurement of morbidity due to injury and illness, and the mortality rate, have been calculated. There were 14 deaths, six due to accidental causes and eight to natural causes, giving a mortality rate of 5·7 per 1,000 for Grimsby deep sea fishermen in 1963. In a year when there was no foundering or loss of Grimsby trawlers, the fatal accident rate of Grimsby trawlermen was more than twice that of fishermen of the United Kingdom, four times the rate for miners, and 40 times that for the manufacturing industries. The most common injuries were, in order of incidence, contusions of varying degrees of severity, infected lesions, sprains and strains, lacerations, and fractures. More than half (56·3%) of the trawlermen were incapacitated by their injuries. The highest rates of incapacity were caused by fractures, contusions, and infected lesions. The upper limb, especially the hands and fingers, was most often affected, resulting most commonly in infected lesions. Third hands, mates, deck hands, deck trimmers, and deck learners had the highest incapacity rates due to injury. Third hands are especially at risk to injury. Most injuries and two deaths caused by casualties to boats occurred in fires aboard trawlers. The most common illnesses suffered by trawlermen were gastrointestinal, respiratory, and skin diseases. Illness caused incapacity in 68·8% of the trawlermen affected. The greatest incapacity was due to gastrointestinal, cardiac, psychiatric, and

  13. DeepPIV: Particle image velocimetry measurements using deep-sea, remotely operated vehicles

    NASA Astrophysics Data System (ADS)

    Katija, Kakani; Sherman, Alana; Graves, Dale; Klimov, Denis; Kecy, Chad; Robison, Bruce

    2015-11-01

    The midwater region of the ocean (below the euphotic zone and above the benthos) is one of the largest ecosystems on our planet, yet remains one of the least explored. Little-known marine organisms that inhabit midwater have developed life strategies that contribute to their evolutionary success, and may inspire engineering solutions for societally relevant challenges. Although significant advances in underwater vehicle technologies have improved access to midwater, small-scale, in situ fluid mechanics measurement methods that seek to quantify the interactions that midwater organisms have with their physical environment are lacking. Here we present DeepPIV, an instrumentation package affixed to remotely operated vehicles that quantifies fluid motions from the surface of the ocean down to 4000 m depths. Utilizing ambient suspended particulate, fluid-structure interactions are evaluated on a range of marine organisms in midwater. Initial science targets include larvaceans, biological equivalents of flapping flexible foils, that create mucus houses to filter food. Little is known about the structure of these mucus houses and the function they play in selectively filtering particles, and these dynamics can serve as particle-mucus models for human health. Using DeepPIV, we reveal the complex structures and flows generated within larvacean mucus houses, and elucidate how these structures function. Funding is gratefully acknowledged from the Packard Foundation.

  14. Species diversity variations in Neogene deep-sea benthic foraminifera at ODP Hole 730A, western Arabian Sea

    NASA Astrophysics Data System (ADS)

    Arumugm, Yuvaraja; Gupta, Anil K.; Panigrahi, Mruganka K.

    2014-10-01

    Deep-sea benthic foraminifera are an important and widely used marine proxy to understand paleoceanographic and paleoclimatic changes on regional and global scales, owing to their sensitivity to oceanic and climatic turnovers. Some species of benthic foraminifera are sensitive to changes in water mass properties whereas others are sensitive to organic fluxes and deep-sea oxygenation. Benthic faunal diversity has been found closely linked to food web, bottom water oxygen levels, and substrate and water mass stability. The present study is aimed at analyzing species diversity trends in benthic foraminifera and their linkages with Indian monsoon variability during the Neogene. Species diversity of benthic foraminifera is examined in terms of number of species (S), information function (H), equitability (E) and Sanders' rarefied values, which were combined with relative abundances of high and low productivity benthic foraminifera at Ocean Drilling Program Hole 730A, Oman margin, western Arabian Sea. The Oman margin offers the best opportunity to understand monsoon-driven changes in benthic diversity since summer monsoon winds have greater impact on the study area. The species diversity was higher during the early Miocene Climatic Optimum (˜17.2-16.4 Ma) followed by a decrease during 16.4-13 Ma coinciding with a major increase in Antarctic ice volume and increased formation of Antarctic Bottom Water. All the diversity parameters show an increase during 13-11.6 Ma, a gradual decrease during 11.6-9 Ma and then an increase with a maximum at 7 Ma. Thereafter the values show little change until 1.2 Ma when all the parameters abruptly decrease. The benthic foraminiferal populations and diversity at Hole 730A were mainly driven by the Indian monsoon, and polar waters might have played a minor or no role since early Neogene period as the Arabian Sea is an enclosed basin.

  15. Reproduction of deep-sea reef-building corals from the southwestern Atlantic

    NASA Astrophysics Data System (ADS)

    Pires, D. O.; Silva, J. C.; Bastos, N. D.

    2014-01-01

    The logistics of research on deep-sea organisms imposes restrictions on studies that require repetitive long-term collections. Studies on the reproduction of deep-water corals have commonly been made without appropriate temporal series. This study included Madrepora oculata, Solenosmilia variabilis, Lophelia pertusa, and Enallopsammia rostrata, which are among the primary deep-sea reef building corals off Brazil. Samples were collected during 13 consecutive months by the Campos Basin Deep-Sea Corals Assessment Project (R&D Center of the Brazilian Energy Company, Petrobras) in Campos Basin (CB) off Rio de Janeiro State through a remotely-operated-vehicle at approximately 600 m depth. Of every monthly sampling campaign, an average of four to five colonies of all four species were investigated histologically. Colonies of both sexes were observed, indicating that all four species are gonochoric. For now, this appears to be the predominant reproductive pattern observed in corals in the area, as well as in deep-sea corals in general, where 80% of coral species are gonochoric. Although considered functionally gonochoric, M. oculata and L. pertusa presented a few colonies with different hermaphroditism patterns. E. rostrata and M. oculata presented continuous reproduction. Although fertile year-round, S. variabilis presents a reproductive peak between April and September (Autumn-Spring) in contrast with the seasonal reproduction recorded in the southwestern Pacific. L. pertusa had a seasonal reproductive peak, confirming previous observations of periodic reproduction in this species in the northeastern Atlantic. The possible spawning season of L. pertusa from CB concentrates between May and July (high frequency of mature gametes), while spawning occurs between January and March in the North Atlantic and between September and November in the Gulf of Mexico. Our results suggest that the studied species are broadcast spawners because no embryos or larvae were observed in any

  16. Potential Mechanisms for Microbial Energy Acquisition in Oxic Deep-Sea Sediments

    PubMed Central

    Heidelberg, John F.

    2016-01-01

    ABSTRACT The South Pacific Gyre (SPG) possesses the lowest rates of sedimentation, surface chlorophyll concentration, and primary productivity in the global oceans. As a direct result, deep-sea sediments are thin and contain small amounts of labile organic carbon. It was recently shown that the entire SPG sediment column is oxygenated and may be representative of up to a third of the global marine environment. To understand the microbial processes that contribute to the removal of the labile organic matter at the water-sediment interface, a sediment sample was collected and subjected to metagenomic sequencing and analyses. Analysis of nine partially reconstructed environmental genomes, which represent approximately one-third of the microbial community, revealed that the members of the SPG surface sediment microbial community are phylogenetically distinct from surface/upper-ocean organisms. These genomes represent a wide distribution of novel organisms, including deep-branching Alphaproteobacteria, two novel organisms within the Proteobacteria, and new members of the Nitrospirae, Nitrospinae, and candidate phylum NC10. These genomes contain evidence for microbially mediated metal (iron/manganese) oxidation and carbon fixation linked to nitrification. Additionally, despite hypothesized energy limitation, members of the SPG microbial community had motility and chemotaxis genes and possessed mechanisms for the degradation of high-molecular-weight organic matter. This study contributes to our understanding of the metabolic potential of microorganisms in deep-sea oligotrophic sediments and their impact on local carbon geochemistry. IMPORTANCE This research provides insight into the microbial metabolic potential of organisms inhabiting oxygenated deep-sea marine sediments. Current estimates suggest that these environments account for up to a third of the global marine sediment habitat. Nine novel deep-sea microbial genomes were reconstructed from a metagenomic data set

  17. Diversity of the benthic macrofauna off northern Namibia from the shelf to the deep sea

    NASA Astrophysics Data System (ADS)

    Eisenbarth, Simone; Zettler, Michael L.

    2016-03-01

    In late summer 2011, shortly after an upwelling event, 17 stations ranging from 30 to 2513 m water depth have been sampled at 20° south in the northern part of the Benguela Current Large Marine Ecosystem (BCLME) for the investigation of the benthic macrofauna. Sediments of this area are dominated by silt. At the time of sampling, oxygen conditions on the shelf were poor (between 0.42 and 0.68 ml l- 1) but not hypoxic. Below 400 m, however, concentrations rose steadily up to 5.28 ml l- 1. Macrozoobenthic communities along this depth gradient are described, revealing among others the community structure for the continental margin area and the deep sea off northern Namibia for the first time. Cluster analysis revealed 5 different communities along the depth gradient with three shelf communities, one continental margin community and one deep-sea community. All in all, 314 different taxa were found with polychaetes being the most abundant group. Diversity index (Shannon) was lowest for the shallow water community with 2.21 and highest for the deep-sea community with 4.79, showing a clear trend with increasing water depth. Species richness, however, reached its maximum with 187 taxa along the continental margin between 400 and 1300 m water depth. Dominant species for each community are named with the two Cumacea, Iphinoeafricana and Upselaspis caparti, being characteristic for the shallow water community. On the shelf, we found surprisingly high biomass values (23-123 g m- 2), mainly caused by polychaetes, the bivalve Sinupharus galatheae and the gastropod Nassarius vinctus. In terms of composition, the remaining communities were dominated by polychaetes with members of the Paraonidae dominating along the continental margin where we also found surprisingly high abundances of the bivalves Pecten sp. and Dosinia sp. Spionid polychaetes and some representatives of the genus Paraonis were the most common organisms for the deep-sea community.

  18. APL-UW Deep Water Propagation 2015-2017: Philippine Sea Data Analysis

    DTIC Science & Technology

    2015-09-30

    Analysis Rex K. Andrew Principal Investigator Applied Physics Laboratory, University of Washington 1013 NE 40th St., Seattle WA 98105 phone: (206) 543-1250...the fundamental statistics of broadband low -frequency acoustical signals evolve during propagation through a dynamically-varying deep ocean. OBJECTIVES...expressions describing the evolution — i.e., the “ physics ” — of statistical properties of the acoustic wavefield. WORK COMPLETED Philippine Sea Analysis

  19. APL-UW Deep Water Propagation: Philippine Sea Signal Physics and North Pacific Ambient Noise

    DTIC Science & Technology

    2015-10-15

    ranges, and (3) the observed pulse intensity distribution at 200 Hz and 510 km (near exponential ) did not obviously follow from the observed pulse spread...distribution is near- exponential , indicative of the saturated scattering regime. The pulse spread is very small, indicative of the partially saturated...Sea 2010 experiment show deep fading. Tntensity fluctuations are near- exponentially distributed and scintillation indices are high (1.1-1.9). According

  20. Search for microaustralites in deep-sea sediments less than 20,000 years old

    NASA Technical Reports Server (NTRS)

    Glass, B. P.; Wu, Jiquan

    1992-01-01

    Several authors have proposed that australites fell less than 20,000 years ago. We searched for microtektites in the tops of 46 deep-sea cores and were unable to find evidence for a microtektite layer less than 20,000 years old. Either the australite fall was not accompanied by microtektites, or the strewnfield did not extend into the area searched, or the australites fell about 0.77 Ma ago as indicated by their radiometric ages.

  1. Measurement of cosmic ray produced Mn-53 in deep sea metallic spherules

    NASA Technical Reports Server (NTRS)

    Nishiizumi, K.; Brownlee, D. E.

    1980-01-01

    Cosmic ray originated Mn-53 nuclides were measured in deep sea metallic spherules by neutron activation analysis. The spherules may be fused micrometeoroids or ablation droplets from larger objects; the low activities of Mn-53 may indicate its evaporation loss resulting from the heating in the earth's atmosphere or short exposure age. The Mn-53 nuclide is now being measured in chondritic spherules, and Be-10 and Cl-36 concentrations are determined in individual spherules using ion counting methods.

  2. Exploring deep sea habitats for baseline characterization using NOAA Ship Okeanos Explorer

    NASA Astrophysics Data System (ADS)

    McKenna, L.; Cantwell, K. L.; Kennedy, B. R.; Lobecker, E.; Sowers, D.; Elliott, K.

    2015-12-01

    In 2015, NOAA Ship Okeanos Explorer, the only US federal ship dedicated to ocean exploration, systematically explored previously unknown deep sea ecosystems in the Caribbean and remote regions in the vicinity of the Hawaiian Islands. Initial characterization of these areas is essential in order to establish a baseline against which to assess potential future changes due to climate and anthropogenic change. In the Caribbean, over 37,500 sq km of previously unmapped seafloor were mapped with a high resolution multibeam revealing rugged canyons along shelf breaks, intricate incised channels, and complex tectonic features. 12 ROV dives, in the 300-6,000 m depth range, visually explored seamounts, escarpments, submarine canyons, and the water column revealing diverse ecosystems and habitats. Discoveries include large assemblages of deep sea corals, range extensions, and observations of several rare and potentially new organisms - including a seastar that had not been documented since its holotype specimen. In the Pacific, over 50,000 sq km of seafloor were mapped in high-resolution, revealing long linear ridge and tectonic fracture zone features, both peaked and flat-topped seamounts, and numerous features that appear to be volcanic in origin. To better understand ecosystem dynamics in depths greater than 2,000 m, the deepest ever ROV surveys and sampling were conducted in remote Pacific island marine sanctuaries and monuments. Novel observations include range extensions and exploration of dense deep sea coral and sponge habitat. Baseline habitat characterization was also conducted on seamounts within the Prime Crust Zone (PCZ), an area with the highest expected concentration of deep-sea minerals in the Pacific. The Hawaiian operations marked the first ever ROV sampling effort conducted onboard Okeanos, and several geological and biological samples are now available at museums and sample repositories in addition to all digital data available through the National

  3. Climatic forcing of Quaternary deep-sea benthic communities in the North Pacific Ocean

    USGS Publications Warehouse

    Yasuhara, Moriaki; Hunt, G.; Cronin, T. M.; Hokanishi, N.; Kawahata, H.; Tsujimoto, Akira; Ishitake, M.

    2012-01-01

    There is growing evidence that changes in deep-sea benthic ecosystems are modulated by climate changes, but most evidence to date comes from the North Atlantic Ocean. Here we analyze new ostracod and published foraminiferal records for the last 250,000 years on Shatsky Rise in the North Pacific Ocean. Using linear models, we evaluate statistically the ability of environmental drivers (temperature, productivity, and seasonality of productivity) to predict changes in faunal diversity, abundance, and composition. These microfossil data show glacial-interglacial shifts in overall abundances and species diversities that are low during glacial intervals and high during interglacials. These patterns replicate those previously documented in the North Atlantic Ocean, suggesting that the climatic forcing of the deep-sea ecosystem is widespread, and possibly global in nature. However, these results also reveal differences with prior studies that probably reflect the isolated nature of Shatsky Rise as a remote oceanic plateau. Ostracod assemblages on Shatsky Rise are highly endemic but of low diversity, consistent with the limited dispersal potential of these animals. Benthic foraminifera, by contrast, have much greater dispersal ability and their assemblages at Shatsky Rise show diversities typical for deep-sea faunas in other regions. Statistical analyses also reveal ostracod-foraminferal differences in relationships between environmental drivers and biotic change. Rarefied diversity is best explained as a hump-shaped function of surface productivity in ostracods, but as having a weak and positive relationship with temperature in foraminifera. Abundance shows a positive relationship with both productivity and seasonality of productivity in foraminifera, and a hump-shaped relationship with productivity in ostracods. Finally, species composition in ostracods is influenced by both temperature and productivity, but only a temperature effect is evident in foraminifera. Though

  4. The geomicrobiology of iron in deep-sea hydrothermal plumes (Invited)

    NASA Astrophysics Data System (ADS)

    Dick, G.; Li, M.; Toner, B. M.; Cron-Kamermans, B.; Baker, B. J.; Breier, J. A.; Sheik, C. S.

    2013-12-01

    Deep-sea hydrothermal vents are a significant source of iron and manganese to the oceans. Microorganisms in deep-sea hydrothermal plumes can influence the form and oceanic fate of vent-derived iron and manganese in several ways, including catalyzing the formation of iron and manganese oxides as well as binding and stabilizing iron with microbially-produced organic carbon. Although the potential role of organic ligands in dispersal of iron from vents is now well established, the nature and source of this organic matter is unknown. Here we present metagenomic, metatranscriptomic, and geochemical insights into the geomicrobiology of iron in deep-sea hydrothermal plumes of the Guaymas Basin (Gulf of California) and Mid-Cayman Rise (Caribbean). In the Guaymas Basin, genes involved in cellular iron uptake pathways, especially those involving siderophores, are among the most highly expressed genes in the plume microbial community. The nature of these microbial iron transporters, taken together with the low concentration of dissolved iron and abundance of particulate iron (mainly maghemite, lepidocrocite, and hematite) in the plume, indicates that iron minerals are the target for this microbial scavenging and uptake. All major Guaymas plume populations, including widespread methanotrophs, lithotrophs, and a particle-associated heterotroph, participate in iron uptake. At the Mid-Cayman Rise, an abundant plume population of Methylophaga has a cluster of genes involved in siderophore production and uptake that are expressed in the plume. These genes are not present in the genomes of other closely-related Methylophaga. Our findings indicate that the mobilization and cellular uptake of iron is a major process in deep-sea hydrothermal plume microbial communities and suggest new mechanisms for generating Fe-C complexes. This 'microbial iron pump' could represent an important yet previously overlooked mode of converting hydrothermal iron into bioavailable forms that can be

  5. Response of Bacterial Communities to Different Detritus Compositions in Arctic Deep-Sea Sediments.

    PubMed

    Hoffmann, Katy; Hassenrück, Christiane; Salman-Carvalho, Verena; Holtappels, Moritz; Bienhold, Christina

    2017-01-01

    Benthic deep-sea communities are largely dependent on particle flux from surface waters. In the Arctic Ocean, environmental changes occur more rapidly than in other ocean regions, and have major effects on the export of organic matter to the deep sea. Because bacteria constitute the majority of deep-sea benthic biomass and influence global element cycles, it is important to better understand how changes in organic matter input will affect bacterial communities at the Arctic seafloor. In a multidisciplinary ex situ experiment, benthic bacterial deep-sea communities from the Long-Term Ecological Research Observatory HAUSGARTEN were supplemented with different types of habitat-related detritus (chitin, Arctic algae) and incubated for 23 days under in situ conditions. Chitin addition caused strong changes in community activity, while community structure remained similar to unfed control incubations. In contrast, the addition of phytodetritus resulted in strong changes in community composition, accompanied by increased community activity, indicating the need for adaptation in these treatments. High-throughput sequencing of the 16S rRNA gene and 16S rRNA revealed distinct taxonomic groups of potentially fast-growing, opportunistic bacteria in the different detritus treatments. Compared to the unfed control, Colwelliaceae, Psychromonadaceae, and Oceanospirillaceae increased in relative abundance in the chitin treatment, whereas Flavobacteriaceae, Marinilabiaceae, and Pseudoalteromonadaceae increased in the phytodetritus treatments. Hence, these groups may constitute indicator taxa for the different organic matter sources at this study site. In summary, differences in community structure and in the uptake and remineralization of carbon in the different treatments suggest an effect of organic matter quality on bacterial diversity as well as on carbon turnover at the seafloor, an important feedback mechanism to be considered in future climate change scenarios.

  6. Possible deep-water gas hydrate accumulations in the Bering Sea

    USGS Publications Warehouse

    Barth, Ginger A.; Scholl, David W.; Childs, Jonathan R.

    2006-01-01

    Seismic reflection images from the deep-water Aleutian and Bowers Basins of the Bering Sea contain many hundreds of acoustic Velocity-AMPlitude (VAMP) anomalies, each of which may represent a large accumulation of natural gas hydrate. Against a backdrop of essentially horizontal sedimentary reflections, the VAMP anomalies stand out as both high-amplitude bright spots and zones of vertically aligned horizon distortions. The VAMPs are interpreted as natural gas chimneys overlain by concentrated hydrate caps.

  7. Nd isotopes in deep-sea corals in the North-eastern Atlantic

    NASA Astrophysics Data System (ADS)

    Copard, Kevin; Colin, Christophe; Douville, Eric; Freiwald, Andre; Gudmundsson, Gudmundur; De Mol, Ben; Frank, Norbert

    2010-09-01

    Neodymium (Nd) concentrations and isotopic signatures of living and fossil deep-sea coral species Lophelia pertusa, Desmophyllum dianthus and Madrepora oculata from the northeast Atlantic Ocean have been investigated in order to test the ability of deep-sea corals to reconstruct the seawater Nd isotopic signature and past changes of ocean circulation in the eastern North Atlantic. Small quantities of Nd—less than 45 ng/g—are incorporated into the aragonite skeleton of living deep-sea corals that dwell at upper intermediate depths throughout the Northeast Atlantic. Rigorous cleaning techniques are needed in order to avoid Nd contamination from manganese-oxide and iron hydroxide coatings. Moreover, Nd isotopic compositions have been measured using thermal ionization mass spectrometry (TIMS) by Nd-oxide method. Our data indicate that the isotopic signatures of modern corals are similar to those of adjacent water masses, implying that deep-sea corals can serve as an archive of the seawater Nd isotopic compositions in the past. The first results from few fully-cleaned fossils corals collected within the Porcupine Seabight and the southwest Rockall Bank reveal significantly higher ɛNd for corals dated between 150 ± 40 and 3060 ± 90 yrs than those of the living corals located in similar areas. This suggests rapid hydrological variations along the eastern margin of the North Atlantic Ocean at intermediate water depth with higher contribution of the Mediterranean Overflow Waters (MOW) or other temperate Atlantic mid-depth water masses (ENACW or NAC) in the past.

  8. Response of Bacterial Communities to Different Detritus Compositions in Arctic Deep-Sea Sediments

    PubMed Central

    Hoffmann, Katy; Hassenrück, Christiane; Salman-Carvalho, Verena; Holtappels, Moritz; Bienhold, Christina

    2017-01-01

    Benthic deep-sea communities are largely dependent on particle flux from surface waters. In the Arctic Ocean, environmental changes occur more rapidly than in other ocean regions, and have major effects on the export of organic matter to the deep sea. Because bacteria constitute the majority of deep-sea benthic biomass and influence global element cycles, it is important to better understand how changes in organic matter input will affect bacterial communities at the Arctic seafloor. In a multidisciplinary ex situ experiment, benthic bacterial deep-sea communities from the Long-Term Ecological Research Observatory HAUSGARTEN were supplemented with different types of habitat-related detritus (chitin, Arctic algae) and incubated for 23 days under in situ conditions. Chitin addition caused strong changes in community activity, while community structure remained similar to unfed control incubations. In contrast, the addition of phytodetritus resulted in strong changes in community composition, accompanied by increased community activity, indicating the need for adaptation in these treatments. High-throughput sequencing of the 16S rRNA gene and 16S rRNA revealed distinct taxonomic groups of potentially fast-growing, opportunistic bacteria in the different detritus treatments. Compared to the unfed control, Colwelliaceae, Psychromonadaceae, and Oceanospirillaceae increased in relative abundance in the chitin treatment, whereas Flavobacteriaceae, Marinilabiaceae, and Pseudoalteromonadaceae increased in the phytodetritus treatments. Hence, these groups may constitute indicator taxa for the different organic matter sources at this study site. In summary, differences in community structure and in the uptake and remineralization of carbon in the different treatments suggest an effect of organic matter quality on bacterial diversity as well as on carbon turnover at the seafloor, an important feedback mechanism to be considered in future climate change scenarios. PMID:28286496

  9. Dispersal, environmental niches and oceanic-scale turnover in deep-sea bivalves.

    PubMed

    McClain, Craig R; Stegen, James C; Hurlbert, Allen H

    2012-05-22

    Patterns of beta-diversity or distance decay at oceanic scales are completely unknown for deep-sea communities. Even when appropriate data exist, methodological problems have made it difficult to discern the relative roles of environmental filtering and dispersal limitation for generating faunal turnover patterns. Here, we combine a spatially extensive dataset on deep-sea bivalves with a model incorporating ecological dynamics and shared evolutionary history to quantify the effects of environmental filtering and dispersal limitation. Both the model and empirical data are used to relate functional, taxonomic and phylogenetic similarity between communities to environmental and spatial distances separating them for 270 sites across the Atlantic Ocean. This study represents the first ocean-wide analysis examining distance decay as a function of a broad suite of explanatory variables. We find that both strong environmental filtering and dispersal limitation drive turnover in taxonomic, functional and phylogenetic composition in deep-sea bivalves, explaining 26 per cent, 34 per cent and 9 per cent of the variation, respectively. This contrasts with previous suggestions that dispersal is not limiting in broad-scale biogeographic and biodiversity patterning in marine systems. However, rates of decay in similarity with environmental distance were eightfold to 44-fold steeper than with spatial distance. Energy availability is the most influential environmental variable evaluated, accounting for 3.9 per cent, 9.4 per cent and 22.3 per cent of the variation in functional, phylogenetic and taxonomic similarity, respectively. Comparing empirical patterns with process-based theoretical predictions provided quantitative estimates of dispersal limitation and niche breadth, indicating that 95 per cent of deep-sea bivalve propagules will be able to persist in environments that deviate from their optimum by up to 2.1 g m(-2) yr(-1) and typically disperse 749 km from their natal site.

  10. Dispersal Patterns of Pleistocene Sands on the North Atlantic Deep-Sea Floor.

    PubMed

    Hubert, J F

    1962-05-04

    Glauconitic, quartzose sands previously modified on the continental shelf from feldspathic glacial detritus were transported through submarine canyons onto the Hudson deep-sea fan, the Hatteras abyssal plain, and the western and central Sohm abyssal plain. These feldspar-poor, quartzose sands contrast with highly feldspathic sands derived directly from a glacial source and probably transported through the Newfoundland abyssal gap onto the eastern and southern Sohm abyssal plain.

  11. Conquered from the deep sea? A new deep-sea isopod species from the Antarctic shelf shows pattern of recent colonization.

    PubMed

    Riehl, Torben; Kaiser, Stefanie

    2012-01-01

    The Amundsen Sea, Antarctica, is amongst the most rapidly changing environments of the world. Its benthic inhabitants are barely known and the BIOPEARL 2 project was one of the first to biologically explore this region. Collected during this expedition, Macrostylis roaldi sp. nov. is described as the first isopod discovered on the Amundsen-Sea shelf. Amongst many characteristic features, the most obvious characters unique for M. roaldi are the rather short pleotelson and short operculum as well as the trapezoid shape of the pleotelson in adult males. We used DNA barcodes (COI) and additional mitochondrial markers (12S, 16S) to reciprocally illuminate morphological results and nucleotide variability. In contrast to many other deep-sea isopods, this species is common and shows a wide distribution. Its range spreads from Pine Island Bay at inner shelf right to the shelf break and across 1,000 m bathymetrically. Its gene pool is homogenized across space and depth. This is indicative for a genetic bottleneck or a recent colonization history. Our results suggest further that migratory or dispersal capabilities of some species of brooding macrobenthos have been underestimated. This might be relevant for the species' potential to cope with effects of climate change. To determine where this species could have survived the last glacial period, alternative refuge possibilities are discussed.

  12. Conquered from the Deep Sea? A New Deep-Sea Isopod Species from the Antarctic Shelf Shows Pattern of Recent Colonization

    PubMed Central

    Riehl, Torben; Kaiser, Stefanie

    2012-01-01

    The Amundsen Sea, Antarctica, is amongst the most rapidly changing environments of the world. Its benthic inhabitants are barely known and the BIOPEARL 2 project was one of the first to biologically explore this region. Collected during this expedition, Macrostylis roaldi sp. nov. is described as the first isopod discovered on the Amundsen-Sea shelf. Amongst many characteristic features, the most obvious characters unique for M. roaldi are the rather short pleotelson and short operculum as well as the trapezoid shape of the pleotelson in adult males. We used DNA barcodes (COI) and additional mitochondrial markers (12S, 16S) to reciprocally illuminate morphological results and nucleotide variability. In contrast to many other deep-sea isopods, this species is common and shows a wide distribution. Its range spreads from Pine Island Bay at inner shelf right to the shelf break and across 1,000 m bathymetrically. Its gene pool is homogenized across space and depth. This is indicative for a genetic bottleneck or a recent colonization history. Our results suggest further that migratory or dispersal capabilities of some species of brooding macrobenthos have been underestimated. This might be relevant for the species’ potential to cope with effects of climate change. To determine where this species could have survived the last glacial period, alternative refuge possibilities are discussed. PMID:23145160

  13. Deep water exchanges between the South China Sea and the Pacific since the last glacial period

    NASA Astrophysics Data System (ADS)

    Wan, Sui; Jian, Zhimin

    2014-12-01

    Deep ocean circulation is widely considered as one of the important factors for increasing CO2 concentration and decreasing radiocarbon activity (Δ14C) of the atmosphere during the last deglaciation. The AMS 14C ages of benthic and planktonic foraminifers from 18 samples of Core MD05-2904 (water depth of 2066 m) in the northern South China Sea (SCS) and 15 samples of Core MD05-2896 (water depth of 1657 m) in the southern SCS were analyzed in this study for reconstructing the intrabasin deep oceanic processes and hence exploring the deep water exchanges between the SCS and the Pacific since the last glacial period. The results show that during the Holocene the average apparent ventilation age of deep water was younger in the southern SCS (~1350 years) than in the northern SCS (~1850 years) due to relatively strong vertical mixing and advection, consistent with modern observations. However, during the last glacial period and deglaciation the deep water was older in the southern SCS (~2050 years and ~1800 to 1200 years, respectively) than in the northern SCS (~1600 years and ~670 years, respectively), indicating reduced deep mixing and advection. Moreover, the northern SCS deep water was significantly younger during the last deglaciation than during the Holocene and the last glacial period, implying the existence of northern sourced newly formed and relatively young North Pacific deep water. Our records do not support the intrusion of anomalously 14C-depleted deep water to the middepth of the low-latitude western Pacific and the SCS during the "Mystery Interval" (17.5-14.5 kyr B.P.).

  14. Scientific Encounters of the Mysterious Sea. Reading Activities That Explore the Mysterious Creatures of the Deep Blue Sea. Grades 4-7.

    ERIC Educational Resources Information Center

    Embry, Lynn

    This activity book presents reading activities for grades 4-7 exploring the mysterious creatures of the deep sea. The creatures include: angel sharks; argonauts; barberfish; comb jelly; croakers; electric rays; flying fish; giganturid; lantern fish; narwhals; northern basket starfish; ocean sunfish; Portuguese man-of-war; sea cucumbers; sea…

  15. Experience of cathodic protection, fabrication and installation of anodes for deep water pipelines in the North Sea and the Norwegian Sea

    SciTech Connect

    Eliassen, S.; Pettersen, N.H.

    1996-08-01

    Statoil is the major operator of the oil and gas pipelines in the North Sea and the Norwegian Sea. Different coating systems have been used for external corrosion protection of the pipelines. The paper presents the company`s experience regarding cathodic protection design and fabrication and installation of anodes for deep water pipelines.

  16. Community transcriptomic assembly reveals microbes that contribute to deep-sea carbon and nitrogen cycling.

    PubMed

    Baker, Brett J; Sheik, Cody S; Taylor, Chris A; Jain, Sunit; Bhasi, Ashwini; Cavalcoli, James D; Dick, Gregory J

    2013-10-01

    The deep ocean is an important component of global biogeochemical cycles because it contains one of the largest pools of reactive carbon and nitrogen on earth. However, the microbial communities that drive deep-sea geochemistry are vastly unexplored. Metatranscriptomics offers new windows into these communities, but it has been hampered by reliance on genome databases for interpretation. We reconstructed the transcriptomes of microbial populations from Guaymas Basin, in the deep Gulf of California, through shotgun sequencing and de novo assembly of total community RNA. Many of the resulting messenger RNA (mRNA) contiguous sequences contain multiple genes, reflecting co-transcription of operons, including those from dominant members. Also prevalent were transcripts with only limited representation (2.8 times coverage) in a corresponding metagenome, including a considerable portion (1.2 Mb total assembled mRNA sequence) with similarity (96%) to a marine heterotroph, Alteromonas macleodii. This Alteromonas and euryarchaeal marine group II populations displayed abundant transcripts from amino-acid transporters, suggesting recycling of organic carbon and nitrogen from amino acids. Also among the most abundant mRNAs were catalytic subunits of the nitrite oxidoreductase complex and electron transfer components involved in nitrite oxidation. These and other novel genes are related to novel Nitrospirae and have limited representation in accompanying metagenomic data. High throughput sequencing of 16S ribosomal RNA (rRNA) genes and rRNA read counts confirmed that Nitrospirae are minor yet widespread members of deep-sea communities. These results implicate a novel bacterial group in deep-sea nitrite oxidation, the second step of nitrification. This study highlights metatranscriptomic assembly as a valuable approach to study microbial communities.

  17. Functional analysis of N-linking oligosaccharyl transferase enzymes encoded by deep-sea vent proteobacteria

    PubMed Central

    Mills, Dominic C.; Jervis, Adrian J.; Abouelhadid, Sherif; Yates, Laura E.; Cuccui, Jon; Linton, Dennis; Wren, Brendan W.

    2016-01-01

    Bacterial N-linking oligosaccharyl transferases (OTase enzymes) transfer lipid-linked glycans to selected proteins in the periplasm and were first described in the intestinal pathogen Campylobacter jejuni, a member of the ε-proteobacteria-subdivision of bacteria. More recently, orthologues from other ε-proteobacterial Campylobacter and Helicobacter species and a δ-proteobacterium, Desulfovibrio desulfuricans, have been described, suggesting that these two subdivisions of bacteria may be a source of further N-linked protein glycosylation systems. Whole-genome sequencing of both ε- and δ-proteobacteria from deep-sea vent habitats, a rich source of species from these subdivisions, revealed putative ORFs encoding OTase enzymes and associated adjacent glycosyltransferases similar to the C. jejuni N-linked glycosylation locus. We expressed putative OTase ORFs from the deep-sea vent species Nitratiruptor tergarcus, Sulfurovum lithotrophicum and Deferribacter desulfuricans in Escherichia coli and showed they were able to functionally complement the C. jejuni OTase, CjPglB . The enzymes were shown to possess relaxed glycan specificity, transferring diverse glycan structures and demonstrated different glycosylation sequon specificities. Additionally a permissive D. desulfuricans acceptor protein was identified, and we provide evidence that the N-linked glycan synthesised by N. tergarcus and S. lithotrophicum contains an acetylated sugar at the reducing end. This work demonstrates that deep-sea vent bacteria encode functional N-glycosylation machineries and are a potential source of biotechnologically important OTase enzymes. PMID:26610891

  18. Biochemical Function and Ecological Significance of Novel Bacterial Lipids in Deep-Sea Procaryotes

    PubMed Central

    DeLong, Edward F.; Yayanos, A. Aristides

    1986-01-01

    The fatty acid composition of the membrane lipids in 11 deep-sea bacterial isolates was determined. The fatty acids observed were typical of marine vibrios except for the presence of large amounts of long-chain polyunsaturated fatty acids (PUFAs). These long-chain PUFAs were previously thought to be absent in procaryotes, with the notable exception of a single marine Flexibacter sp. In three barophilic strains tested at 2°C, there was a general increase in the relative amount of PUFAs as pressure was increased from a low growth pressure towards the optimal growth pressure. In Vibrio marinus MP-1, a psychrophilic strain, PUFAs were found to increase as a function of decreasing temperature at constant atmospheric pressure. These results suggest the involvement of PUFAs in the maintenance of optimal membrane fluidity and function over environmentally relevant temperatures and pressures. Furthermore, since these lipids are essential nutrients for higher taxa and are found in large amounts in the lipids of deep-sea vertebrates and invertebrates, an important, specific role for deep-sea bacteria in abyssal food webs is implicated. PMID:16347037

  19. Molecular phylogeny of hemichordata, with updated status of deep-sea enteropneusts.

    PubMed

    Cannon, Johanna T; Rychel, Amanda L; Eccleston, Heather; Halanych, Kenneth M; Swalla, Billie J

    2009-07-01

    Hemichordates have occupied a central role in hypotheses of deuterostome and early chordate evolution. However, surprisingly little is understood about evolution within hemichordates, including hemichordate ancestral characters that may relate to other deuterostome taxa. Previous phylogenetic studies suggested that enteropneust worms are either monophyletic (based on 28S rDNA) or paraphyletic (based on 18S rDNA). Here, we expand the number of hemichordate taxa used in phylogenetic analyses for 18S rDNA data and employ more quickly evolving mitochondrial gene sequences. Novel data from an undescribed deep-sea enteropneust species similar to Torquarator bullocki and a Gulf Stream tornaria larva suggest that these taxa are closely allied to or possibly within Ptychoderidae. Saxipendium coronatum, another deep-sea species commonly called the spaghetti worm, is shown to be a member of Harrimaniidae. Recognition of these deep-sea lineages as distinct families calls into question features used in hemichordate taxonomy. In the new analyses, enteropneusts fall into two distinct monophyletic clades, with the colonial pterobranchs sister to Harrimaniidae, similar to earlier published 18S results. These results indicate that colonial pterobranchs may have evolved from a solitary acorn worm-like hemichordate ancestor. If true, pterobranchs would be unlikely to represent the deuterostome ancestral form as has been suggested by many traditional theories of deuterostome evolution.

  20. Macroecological drivers of archaea and bacteria in benthic deep-sea ecosystems

    PubMed Central

    Danovaro, Roberto; Molari, Massimiliano; Corinaldesi, Cinzia; Dell’Anno, Antonio

    2016-01-01

    Bacteria and archaea dominate the biomass of benthic deep-sea ecosystems at all latitudes, playing a crucial role in global biogeochemical cycles, but their macroscale patterns and macroecological drivers are still largely unknown. We show the results of the most extensive field study conducted so far to investigate patterns and drivers of the distribution and structure of benthic prokaryote assemblages from 228 samples collected at latitudes comprising 34°N to 79°N, and from ca. 400- to 5570-m depth. We provide evidence that, in deep-sea ecosystems, benthic bacterial and archaeal abundances significantly increase from middle to high latitudes, with patterns more pronounced for archaea, and particularly for Marine Group I Thaumarchaeota. Our results also reveal that different microbial components show varying sensitivities to changes in temperature conditions and food supply. We conclude that climate change will primarily affect deep-sea benthic archaea, with important consequences on global biogeochemical cycles, particularly at high latitudes. PMID:27386507

  1. Is the deep-sea crab Chaceon affinis able to induce a thermal stress response?

    PubMed

    Mestre, Nélia C; Cottin, Delphine; Bettencourt, Raul; Colaço, Ana; Correia, Sérgio P C; Shillito, Bruce; Thatje, Sven; Ravaux, Juliette

    2015-03-01

    Fluctuations in the stress level of an organism are expressed in behavioural and molecular changes that can affect its ecology and survival. Our knowledge of thermal adaptations in deep-sea organisms is very limited, and this study investigates the critical thermal maximum (CTmax) and the heat-shock response (HSR) in the deep-sea crab Chaceon affinis commonly found in waters of the North East Atlantic. A mild but significant HSR in C. affinis was noted and one of the lowest CTmax known amongst Crustacea was revealed (27.5 °C at 0.1 MPa; 28.5 °C at 10 MPa). The thermal sensitivity of this species appears to be reduced at in situ pressure (10 MPa), given the slightly higher CTmax and the significant 3-fold induction of stress genes hsp70 form 1 and hsp70 form 2. Although C. affinis deep-sea habitat is characterized by overall low temperature this species appears to have retained its ability to induce a HSR. This capability may be linked with C. affinis' occasional exploitation of warmer and thermally instable hydrothermal vent fields, where it has been found foraging for food.

  2. Endemicity of the cosmopolitan mesophilic chemolithoautotroph Sulfurimonas at deep-sea hydrothermal vents.

    PubMed

    Mino, Sayaka; Nakagawa, Satoshi; Makita, Hiroko; Toki, Tomohiro; Miyazaki, Junichi; Sievert, Stefan M; Polz, Martin F; Inagaki, Fumio; Godfroy, Anne; Kato, Shingo; Watanabe, Hiromi; Nunoura, Takuro; Nakamura, Koichi; Imachi, Hiroyuki; Watsuji, Tomo-O; Kojima, Shigeaki; Takai, Ken; Sawabe, Tomoo

    2017-04-01

    Rich animal and microbial communities have been found at deep-sea hydrothermal vents. Although the biogeography of vent macrofauna is well understood, the corresponding knowledge about vent microbial biogeography is lacking. Here, we apply the multilocus sequence analysis (MLSA) to assess the genetic variation of 109 Sulfurimonas strains with ⩾98% 16S rRNA gene sequence similarity, which were isolated from four different geographical regions (Okinawa Trough (OT), Mariana Volcanic Arc and Trough (MVAT), Central Indian Ridge (CIR) and Mid-Atlantic Ridge (MAR)). Sequence typing based on 11 protein-coding genes revealed high genetic variation, including some allele types that are widespread within regions, resulting in 102 nucleotide sequence types (STs). This genetic variation was predominantly due to mutation rather than recombination. Phylogenetic analysis of the 11 concatenated genes showed a clear geographical isolation corresponding to the hydrothermal regions they originated from, suggesting limited dispersal. Genetic differentiation among Sulfurimonas populations was primarily influenced by geographical distance rather than gas composition of vent fluid or habitat, although in situ environmental conditions of each microhabitat could not be examined. Nevertheless, Sulfurimonas may possess a higher dispersal capability compared with deep-sea hydrothermal vent thermophiles. This is the first report on MLSA of deep-sea hydrothermal vent Epsilonproteobacteria, which is indicative of allopatric speciation.

  3. A novel fluorescent protein from the deep-sea anemone Cribrinopsis japonica (Anthozoa: Actiniaria)

    PubMed Central

    Tsutsui, Kenta; Shimada, Eriko; Ogawa, Tomohisa; Tsuruwaka, Yusuke

    2016-01-01

    A fluorescent protein was identified and cloned from the deep-sea anemone Cribrinopsis japonica. Bioluminescence and fluorescence expression were examined by direct observations of live specimens and RNA-Seq analysis. Both approaches revealed a novel green fluorescent protein in the tentacles of the anemone, but bioluminescence was not observed. Behavioural observations revealed that a blue light excited the fluorescence in the tentacles, and initiated a behavioural response whereby the fluorescent tentacles became fully exposed to the blue light. The excitation and emission peaks of C. japonica’s fluorescent protein were at 500 and 510 nm, respectively, which were greener than those reported in homologs. Furthermore, this protein was highly tolerant of increased temperatures and repeated freeze–thaw treatments. The current study presents an example of fluorescence in a deep-sea cnidarian, demonstrating that fluorescent proteins could have important roles, regardless of the presence or absence of strong sunlight. It also demonstrates that this deep-sea fluorescent protein has unique characteristics, including high stability, perhaps as an adaptation to the extreme environment. PMID:27002644

  4. Molecular phylogeny in mytilids supports the wooden steps to deep-sea vents hypothesis.

    PubMed

    Samadi, Sarah; Quéméré, Erwan; Lorion, Julien; Tillier, Annie; von Cosel, Rudo; Lopez, Philippe; Cruaud, Corinne; Couloux, Arnaud; Boisselier-Dubayle, Marie-Catherine

    2007-05-01

    Molecular data were used to study the diversity of mytilids associated with sunken-woods sampled in the Solomon Islands and discuss the 'wooden steps to deep-sea vent' hypothesis proposed by Distel et al. First, COI data used in a barcoding approach confirm the presence of four distinct species. Analyses of the 18S rDNA and COI dataset then confirmed that these sunken-wood mytilids belonged to a monophyletic group including all species from deep-sea reducing environments. Finally, we analyzed the relationships within this monophyletic group that include the Bathymodiolinae using a COI dataset and a combined analysis of mitochondrial COI and ND4 genes and nuclear rDNA 18S and 28S. Our study supported the 'wooden steps to deep-sea vent' hypothesis: one of the sunken-wood species had a basal position within the Bathymodiolionae, and all described vent and seep mussels included in our analyses were derived taxa within Bathymodiolinae.

  5. Bacterial community diversity of the deep-sea octocoral Paramuricea placomus

    USGS Publications Warehouse

    Kellogg, Christina A.; Ross, Steve W.; Brooke, Sandra D.

    2016-01-01

    Compared to tropical corals, much less is known about deep-sea coral biology and ecology. Although the microbial communities of some deep-sea corals have been described, this is the first study to characterize the bacterial community associated with the deep-sea octocoral, Paramuricea placomus. Samples from five colonies of P. placomus were collected from Baltimore Canyon (379–382 m depth) in the Atlantic Ocean off the east coast of the United States of America. DNA was extracted from the coral samples and 16S rRNA gene amplicons were pyrosequenced using V4-V5 primers. Three samples sequenced deeply (>4,000 sequences each) and were further analyzed. The dominant microbial phylum was Proteobacteria, but other major phyla included Firmicutes and Planctomycetes. A conserved community of bacterial taxa held in common across the three P. placomuscolonies was identified, comprising 68–90% of the total bacterial community depending on the coral individual. The bacterial community of P. placomusdoes not appear to include the genus Endozoicomonas, which has been found previously to be the dominant bacterial associate in several temperate and tropical gorgonians. Inferred functionality suggests the possibility of nitrogen cycling by the core bacterial community.

  6. Bathymetric limits of chondrichthyans in the deep sea: A re-evaluation

    NASA Astrophysics Data System (ADS)

    Musick, J. A.; Cotton, C. F.

    2015-05-01

    Chondrichthyans are largely absent in abyssal (>3000 m) habitats in most regions of the world ocean and are uncommon below 2000 m. The deeper-living chondrichthyans include certain rajids, squaliforms and holocephalans. Several hypotheses have been erected to explain the absence of chondrichthyans from the abyss. These are mostly based on energetics: deep-sea food webs are impoverished due to their distance from primary production, and chondrichthyans, occupying the highest trophic levels, cannot be supported due to entropy among trophic levels. We examined this hypothesis by comparing trophic levels, calculated from dietary data, of deep-sea chondrichthyans with those of deep-sea teleosts. Chondrichthyans were mostly above trophic level 4, whereas all the teleosts examined were below that level. Both small and medium squaloids, as well as sharks and skates of large size, feed on fishes, cephalopods and scavenged prey, and thus occupy the highest trophic levels in bathydemersal fish communities. In addition, whereas teleosts and chondrichthyans both store lipids in their livers to support long periods of fasting, chondrichthyans must devote much of their liver lipids to maintain neutral buoyancy. Consequently teleosts with swim bladders are better adapted to survive in the abyss where food sources are sparse and unpredictable. The potential prey field for both chondrichthyans and teleosts declines in biomass and diversity with depth, but teleosts have more flexibility in their feeding mechanisms and food habits, and occupy abyssal trophic guilds for which chondrichthyans are ill adapted.

  7. Functional analysis of N-linking oligosaccharyl transferase enzymes encoded by deep-sea vent proteobacteria.

    PubMed

    Mills, Dominic C; Jervis, Adrian J; Abouelhadid, Sherif; Yates, Laura E; Cuccui, Jon; Linton, Dennis; Wren, Brendan W

    2016-04-01

    Bacterial N-linking oligosaccharyl transferases (OTase enzymes) transfer lipid-linked glycans to selected proteins in the periplasm and were first described in the intestinal pathogen Campylobacter jejuni, a member of the ε-proteobacteria-subdivision of bacteria. More recently, orthologues from other ε-proteobacterial Campylobacter and Helicobacter species and a δ-proteobacterium, Desulfovibrio desulfuricans, have been described, suggesting that these two subdivisions of bacteria may be a source of further N-linked protein glycosylation systems. Whole-genome sequencing of both ε- and δ-proteobacteria from deep-sea vent habitats, a rich source of species from these subdivisions, revealed putative ORFs encoding OTase enzymes and associated adjacent glycosyltransferases similar to the C. jejuni N-linked glycosylation locus. We expressed putative OTase ORFs from the deep-sea vent species Nitratiruptor tergarcus, Sulfurovum lithotrophicum and Deferribacter desulfuricans in Escherichia coli and showed that they were able to functionally complement the C. jejuni OTase, CjPglB. The enzymes were shown to possess relaxed glycan specificity, transferring diverse glycan structures and demonstrated different glycosylation sequon specificities. Additionally, a permissive D. desulfuricans acceptor protein was identified, and we provide evidence that the N-linked glycan synthesized by N. tergarcus and S. lithotrophicum contains an acetylated sugar at the reducing end. This work demonstrates that deep-sea vent bacteria encode functional N-glycosylation machineries and are a potential source of biotechnologically important OTase enzymes.

  8. The Specific and Exclusive Microbiome of the Deep-Sea Bone-Eating Snail, Rubyspira osteovora.

    PubMed

    Aronson, H S; Zellmer, A J; Goffredi, S K

    2016-12-15

    Rubyspira osteovora is an unusual deep-sea snail from Monterey Canyon, CA. This group has only been found on decomposing whales and is thought to use bone as a novel source of nutrition. This study characterized the gut microbiome of R. osteovora, compared to the surrounding environment, as well as to other deep-sea snails with more typical diets. Analysis of 16S rRNA gene sequences revealed that R. osteovora digestive tissues hosted a much lower bacterial diversity (average Shannon index of 1.9; n = 12), compared to environmental samples (average Shannon index of 4.4; n = 2) and were dominated by two bacterial genera: Mycoplasma and Psychromonas (comprising up to 56% and 42% average total recovered sequences, respectively). These two bacteria, along with Psychrilyobacter sp. (∼16% average recovered sequences), accounted for between 43-92% of the total recovered sequences in individual snail digestive systems, with other OTUs present at much lower proportions. The relative abundance of these three groups remained similar over six years of sampling (collection date was not shown to be a significant predictor of community structure), suggesting a long-term association. Further, these bacterial genera were either not present (Mycoplasma and Psychromonas), or at very low abundance (< 0.04% for Psychrilyobacter), in environmental samples and other deep-sea gastropods, supporting the uniqueness of the R. osteovora gut microbiome.

  9. Hydroxylated PAHs in bile of deep-sea fish. Relationship with xenobiotic metabolizing enzymes

    SciTech Connect

    Escartin, E.; Porte, C.

    1999-08-15

    Polycyclic aromatic hydrocarbon (PAH) pollution in deep-sea environments has been assessed by measuring bile PAH metabolites in deep-sea fish. Five species from the NW Mediterranean were selected for the study: Coryphaenoides guentheri, Lepidion lepidion, Mora moro, Bathypterois mediterraneus, and Alepocephalus rostratus. Bile crude samples were directly analyzed by HPLC-fluorescence at the excitation/emission wavelengths of benzo[a]pyrene. Differences among sampling sites were recorded, which suggests that coastal discharges of contaminants may reach these remote areas. Subsequently, a number of bile samples were hydrolyzed and analyzed by gas chromatography--mass spectrometry (GC-MS) for the determination of individual PAHs. 1-Pyrenol and 2-phenylphenol were among the most abundant compounds detected. The results obtained confirm the long-range transport of PAHs to deep-sea environments, subsequent exposure of fish inhabiting those remote areas, and its ability to metabolize and excrete them through the bile. The data also describe hepatic enzymes (cytochrome P450 and glutathione S-transferases) that appear to be as catalytically efficient as those in shallow water species.

  10. The past, present and future distribution of a deep-sea shrimp in the Southern Ocean

    PubMed Central

    Costello, Mark J.

    2016-01-01

    Shrimps have a widespread distribution across the shelf, slope and seamount regions of the Southern Ocean. Studies of Antarctic organisms have shown that individual species and higher taxa display different degrees of sensitivity and adaptability in response to environmental change. We use species distribution models to predict changes in the geographic range of the deep-sea Antarctic shrimp Nematocarcinus lanceopes under changing climatic conditions from the Last Glacial Maximum to the present and to the year 2100. The present distribution range indicates a pole-ward shift of the shrimp population since the last glaciation. This occurred by colonization of slopes from nearby refugia located around the northern part of Scotia Arc, southern tip of South America, South Georgia, Bouvet Island, southern tip of the Campbell plateau and Kerguelen plateau. By 2100, the shrimp are likely to expand their distribution in east Antarctica but have a continued pole-ward contraction in west Antarctica. The range extension and contraction process followed by the deep-sea shrimp provide a geographic context of how other deep-sea Antarctic species may have survived during the last glaciation and may endure with projected changing climatic conditions in the future. PMID:26925334

  11. Bacterial community diversity of the deep-sea octocoral Paramuricea placomus

    PubMed Central

    Ross, Steve W.; Brooke, Sandra D.

    2016-01-01

    Compared to tropical corals, much less is known about deep-sea coral biology and ecology. Although the microbial communities of some deep-sea corals have been described, this is the first study to characterize the bacterial community associated with the deep-sea octocoral, Paramuricea placomus. Samples from five colonies of P. placomus were collected from Baltimore Canyon (379–382 m depth) in the Atlantic Ocean off the east coast of the United States of America. DNA was extracted from the coral samples and 16S rRNA gene amplicons were pyrosequenced using V4-V5 primers. Three samples sequenced deeply (>4,000 sequences each) and were further analyzed. The dominant microbial phylum was Proteobacteria, but other major phyla included Firmicutes and Planctomycetes. A conserved community of bacterial taxa held in common across the three P. placomus colonies was identified, comprising 68–90% of the total bacterial community depending on the coral individual. The bacterial community of P. placomus does not appear to include the genus Endozoicomonas, which has been found previously to be the dominant bacterial associate in several temperate and tropical gorgonians. Inferred functionality suggests the possibility of nitrogen cycling by the core bacterial community. PMID:27703865

  12. Deep-sea hydrothermal vent bacteria related to human pathogenic Vibrio species

    PubMed Central

    Hasan, Nur A.; Grim, Christopher J.; Lipp, Erin K.; Rivera, Irma N. G.; Chun, Jongsik; Haley, Bradd J.; Taviani, Elisa; Choi, Seon Young; Hoq, Mozammel; Munk, A. Christine; Brettin, Thomas S.; Bruce, David; Challacombe, Jean F.; Detter, J. Chris; Han, Cliff S.; Eisen, Jonathan A.; Huq, Anwar; Colwell, Rita R.

    2015-01-01

    Vibrio species are both ubiquitous and abundant in marine coastal waters, estuaries, ocean sediment, and aquaculture settings worldwide. We report here the isolation, characterization, and genome sequence of a novel Vibrio species, Vibrio antiquarius, isolated from a mesophilic bacterial community associated with hydrothermal vents located along the East Pacific Rise, near the southwest coast of Mexico. Genomic and phenotypic analysis revealed V. antiquarius is closely related to pathogenic Vibrio species, namely Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio harveyi, and Vibrio vulnificus, but sufficiently divergent to warrant a separate species status. The V. antiquarius genome encodes genes and operons with ecological functions relevant to the environment conditions of the deep sea and also harbors factors known to be involved in human disease caused by freshwater, coastal, and brackish water vibrios. The presence of virulence factors in this deep-sea Vibrio species suggests a far more fundamental role of these factors for their bacterial host. Comparative genomics revealed a variety of genomic events that may have provided an important driving force in V. antiquarius evolution, facilitating response to environmental conditions of the deep sea. PMID:25964331

  13. The detection of magnetotactic bacteria in deep sea sediments from the east Pacific Manganese Nodule Province.

    PubMed

    Dong, Yi; Li, Jinhua; Zhang, Wuchang; Zhang, Wenyan; Zhao, Yuan; Xiao, Tian; Wu, Long-Fei; Pan, Hongmiao

    2016-04-01

    Magnetotactic bacteria (MTB) are distributed ubiquitously in sediments from coastal environments to the deep sea. The Pacific Manganese Nodule Province contains numerous polymetallic nodules mainly composed of manganese, iron, cobalt, copper and nickel. In the present study we used Illumina MiSeq sequencing technology to assess the communities of putative MTB in deep sea surface sediments at nine stations in the east Pacific Manganese Nodule Province. A total of 402 sequence reads from MTB were classified into six operational taxonomic units (OTUs). Among these, OTU113 and OTU759 were affiliated with the genus Magnetospira, OTU2224 and OTU2794 were affiliated with the genus Magnetococcus and Magnetovibrio, respectively, OTU3017 had no known genus affiliation, and OTU2556 was most similar to Candidatus Magnetananas. Interestingly, OTU759 was widely distributed, occurring at all study sites. Magnetism measurements revealed that all sediments were dominated by low coercivity, non-interacting single domain magnetic minerals. Transmission electron microscopy confirmed that the magnetic minerals were magnetosomes. Our data suggest that diverse putative MTB are widely distributed in deep sea surface sediments from the east Pacific Manganese Nodule Province.

  14. Chronic and intensive bottom trawling impairs deep-sea biodiversity and ecosystem functioning

    PubMed Central

    Pusceddu, Antonio; Bianchelli, Silvia; Martín, Jacobo; Puig, Pere; Palanques, Albert; Masqué, Pere; Danovaro, Roberto

    2014-01-01

    Bottom trawling has many impacts on marine ecosystems, including seafood stock impoverishment, benthos mortality, and sediment resuspension. Historical records of this fishing practice date back to the mid-1300s. Trawling became a widespread practice in the late 19th century, and it is now progressively expanding to greater depths, with the concerns about its sustainability that emerged during the first half of the 20th century now increasing. We show here that compared with untrawled areas, chronically trawled sediments along the continental slope of the north-western Mediterranean Sea are characterized by significant decreases in organic matter content (up to 52%), slower organic carbon turnover (ca. 37%), and reduced meiofauna abundance (80%), biodiversity (50%), and nematode species richness (25%). We estimate that the organic carbon removed daily by trawling in the region under scrutiny represents as much as 60–100% of the input flux. We anticipate that such an impact is causing the degradation of deep-sea sedimentary habitats and an infaunal depauperation. With deep-sea trawling currently conducted along most continental margins, we conclude that trawling represents a major threat to the deep seafloor ecosystem at the global scale. PMID:24843122

  15. An efficient multi-locus mixed-model approach for genome-wide association studies in structured populations.

    PubMed

    Segura, Vincent; Vilhjálmsson, Bjarni J; Platt, Alexander; Korte, Arthur; Seren, Ümit; Long, Quan; Nordborg, Magnus

    2012-06-17

    Population structure causes genome-wide linkage disequilibrium between unlinked loci, leading to statistical confounding in genome-wide association studies. Mixed models have been shown to handle the confounding effects of a diffuse background of large numbers of loci of small effect well, but they do not always account for loci of larger effect. Here we propose a multi-locus mixed model as a general method for mapping complex traits in structured populations. Simulations suggest that our method outperforms existing methods in terms of power as well as false discovery rate. We apply our method to human and Arabidopsis thaliana data, identifying new associations and evidence for allelic heterogeneity. We also show how a priori knowledge from an A. thaliana linkage mapping study can be integrated into our method using a Bayesian approach. Our implementation is computationally efficient, making the analysis of large data sets (n > 10,000) practicable.

  16. Metabolic profiles of prokaryotic and eukaryotic communities in deep-sea sponge Neamphius huxleyi indicated by metagenomics

    PubMed Central

    Li, Zhi-Yong; Wang, Yue-Zhu; He, Li-Ming; Zheng, Hua-Jun

    2014-01-01

    The whole metabolism of a sponge holobiont and the respective contributions of prokaryotic and eukaryotic symbionts and their associations with the sponge host remain largely unclear. Meanwhile, compared with shallow water sponges, deep-sea sponges are rarely understood. Here we report the metagenomic exploration of deep-sea sponge Neamphius huxleyi at the whole community level. Metagenomic data showed phylogenetically diverse prokaryotes and eukaryotes in Neamphius huxleyi. MEGAN and gene enrichment analyses indicated different metabolic potentials of prokaryotic symbionts from eukaryotic symbionts, especially in nitrogen and carbon metabolisms, and their molecular interactions with the sponge host. These results supported the hypothesis that prokaryotic and eukaryotic symbionts have different ecological roles and relationships with sponge host. Moreover, vigorous denitrification, and CO2 fixation by chemoautotrophic prokaryotes were suggested for this deep-sea sponge. The study provided novel insights into the respective potentials of prokaryotic and eukaryotic symbionts and their associations with deep-sea sponge Neamphius huxleyi. PMID:24463735

  17. Metabolic profiles of prokaryotic and eukaryotic communities in deep-sea sponge Neamphius huxleyi [corrected]. indicated by metagenomics.

    PubMed

    Li, Zhi-Yong; Wang, Yue-Zhu; He, Li-Ming; Zheng, Hua-Jun

    2014-01-27

    The whole metabolism of a sponge holobiont and the respective contributions of prokaryotic and eukaryotic symbionts and their associations with the sponge host remain largely unclear. Meanwhile, compared with shallow water sponges, deep-sea sponges are rarely understood. Here we report the metagenomic exploration of deep-sea sponge Neamphius huxleyi [corrected] . at the whole community level. Metagenomic data showed phylogenetically diverse prokaryotes and eukaryotes in Neamphius huxleyi [corrected]. MEGAN and gene enrichment analyses indicated different metabolic potentials of prokaryotic symbionts from eukaryotic symbionts, especially in nitrogen and carbon metabolisms, and their molecular interactions with the sponge host. These results supported the hypothesis that prokaryotic and eukaryotic symbionts have different ecological roles and relationships with sponge host. Moreover, vigorous denitrification, and CO2 fixation by chemoautotrophic prokaryotes were suggested for this deep-sea sponge. The study provided novel insights into the respective potentials of prokaryotic and eukaryotic symbionts and their associations with deep-sea sponge Neamphius huxleyi [corrected].

  18. Carbonate "clumped" isotope signatures in aragonitic scleractinian and calcitic gorgonian deep-sea corals

    NASA Astrophysics Data System (ADS)

    Kimball, Justine; Eagle, Robert; Dunbar, Robert

    2016-12-01

    Deep-sea corals are a potentially valuable archive of the temperature and ocean chemistry of intermediate and deep waters. Living in near-constant temperature, salinity, and pH and having amongst the slowest calcification rates observed in carbonate-precipitating biological organisms, deep-sea corals can provide valuable constraints on processes driving mineral equilibrium and disequilibrium isotope signatures. Here we report new data to further develop "clumped" isotopes as a paleothermometer in deep-sea corals as well as to investigate mineral-specific, taxon-specific, and growth-rate-related effects. Carbonate clumped isotope thermometry is based on measurements of the abundance of the doubly substituted isotopologue 13C18O16O2 in carbonate minerals, analyzed in CO2 gas liberated on phosphoric acid digestion of carbonates and reported as Δ47 values. We analyzed Δ47 in live-collected aragonitic scleractinian (Enallopsammia sp.) and high-Mg calcitic gorgonian (Isididae and Coralliidae) deep-sea corals and compared results to published data for other aragonitic scleractinian taxa. Measured Δ47 values were compared to in situ temperatures, and the relationship between Δ47 and temperature was determined for each group to investigate taxon-specific effects. We find that aragonitic scleractinian deep-sea corals exhibit higher values than high-Mg calcitic gorgonian corals and the two groups of coral produce statistically different relationships between Δ47-temperature calibrations. These data are significant in the interpretation of all carbonate clumped isotope calibration data as they show that distinct Δ47-temperature calibrations can be observed in different materials recovered from the same environment and analyzed using the same instrumentation, phosphoric acid composition, digestion temperature and technique, CO2 gas purification apparatus, and data handling. There are three possible explanations for the origin of these different calibrations. The offset

  19. Carbonate “clumped” isotope signatures in aragonitic scleractinian and calcitic gorgonian deep-sea corals

    DOE PAGES

    Kimball, Justine; Eagle, Robert; Dunbar, Robert

    2016-12-12

    Deep-sea corals are a potentially valuable archive of the temperature and ocean chemistry of intermediate and deep waters. Living in near-constant temperature, salinity, and pH and having amongst the slowest calcification rates observed in carbonate-precipitating biological organisms, deep-sea corals can provide valuable constraints on processes driving mineral equilibrium and disequilibrium isotope signatures. Here we report new data to further develop “clumped” isotopes as a paleothermometer in deep-sea corals as well as to investigate mineral-specific, taxon-specific, and growth-rate-related effects. Carbonate clumped isotope thermometry is based on measurements of the abundance of the doubly substituted isotopologue 13C18O16O2 in carbonate minerals, analyzed inmore » CO2 gas liberated on phosphoric acid digestion of carbonates and reported as Δ47 values. We analyzed Δ47 in live-collected aragonitic scleractinian (Enallopsammia sp.) and high-Mg calcitic gorgonian (Isididae and Coralliidae) deep-sea corals and compared results to published data for other aragonitic scleractinian taxa. Measured Δ47 values were compared to in situ temperatures, and the relationship between Δ47 and temperature was determined for each group to investigate taxon-specific effects. We find that aragonitic scleractinian deep-sea corals exhibit higher values than high-Mg calcitic gorgonian corals and the two groups of coral produce statistically different relationships between Δ47–temperature calibrations. These data are significant in the interpretation of all carbonate clumped isotope calibration data as they show that distinct Δ47–temperature calibrations can be observed in different materials recovered from the same environment and analyzed using the same instrumentation, phosphoric acid composition, digestion temperature and technique, CO2 gas purification apparatus, and data handling. There are three possible explanations for the origin of these different

  20. Carbonate "clumped" isotope signatures in aragonitic scleractinian and calcitic gorgonian deep-sea corals

    NASA Astrophysics Data System (ADS)

    Kimball, J.; Tripati, R. E.; Dunbar, R.

    2015-12-01

    Deep-sea corals are a potentially valuable archive of the temperature and ocean chemistry of intermediate and deep waters. Living in near constant temperature, salinity and pH, and having amongst the slowest calcification rates observed in carbonate-precipitating biological organisms, deep-sea corals can provide valuable constraints on processes driving mineral equilibrium and disequilibrium isotope signatures. Here we report new data to further develop "clumped" isotopes as a paleothermometer in deep-sea corals as well as to investigate mineral-specific, taxon-specific, and growth-rate related effects. Carbonate clumped isotope thermometry is based on measurements of the abundance of the doubly-substituted isotopologue 13C18O16O2 in carbonate minerals, analyzed in CO2 gas liberated on phosphoric acid digestion of carbonates and reported as Δ47 values. We analyzed Δ47 in live-collected aragonitic scleractinian (Enallopsammia sp.) and calcitic gorgonian (Isididae and Coralliidae) deep-sea corals, and compared results to published data for other aragonitic scleractinian taxa. Measured Δ47 values were compared to in situ temperatures and the relationship between Δ47 and temperature was determined for each group to investigate taxon-specific effects. We find that aragonitic scleractinian deep-sea corals exhibit higher values than calcitic gorgonian corals and the two groups of coral produce statistically different relationship between Δ47-temperature calibrations. These data are significant in the interpretation of all carbonate "clumped" isotope calibration data as they show that distinct Δ47-temperature calibrations can be observed in different materials recovered from the same environment and analyzed using the same instrumentation, phosphoric acid composition, digestion temperature and technique, CO2 gas purification apparatus, and data handling. There are three possible explanations for the origin of these different calibrations. The offset between the

  1. Deep-sea ostracode shell chemistry (Mg:Ca ratios) and late Quaternary Arctic Ocean history

    USGS Publications Warehouse

    Cronin, T. M.; Dwyer, G.S.; Baker, P.A.; Rodriguez-Lazaro, J.; Briggs, W.M.; ,

    1996-01-01

    The magnesium:calcium (Mg:Ca) and strontium:calcium (Sr:Ca) ratios were investigated in shells of the benthic ostracode genus Krithe obtained from 64 core-tops from water depths of 73 to 4411 m in the Arctic Ocean and Nordic seas to determine the potential of ostracode shell chemistry for paleoceanographic study. Shells from the abyssal plain and ridges of the Nansen, Amundsen and Makarov basins and the Norwegian and Greenland seas had a wide scatter of Mg:Ca ratios ranging from 0.007 to 0.012 that may signify post-mortem chemical alteration of the shells from Arctic deep-sea environments below about 1000 m water depth. There is a positive correlation (r2=0.59) between Mg:Ca ratios and bottom-water temperature in Krithe shells from water depths <900 m.

  2. The Biological Deep Sea Hydrothermal Vent as a Model to Study Carbon Dioxide Capturing Enzymes

    PubMed Central

    Minic, Zoran; Thongbam, Premila D.

    2011-01-01

    Deep sea hydrothermal vents 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. PMID:21673885

  3. The biological deep sea hydrothermal vent as a model to study carbon dioxide capturing enzymes.

    PubMed

    Minic, Zoran; Thongbam, Premila D

    2011-01-01

    Deep sea hydrothermal vents 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.

  4. Growth rate of a deep-sea coral using sup 210 Pb and other isotopes

    SciTech Connect

    Druffel, E.R.M.; King, L.I.; Belastock, R.A.; Buesseler, K.O. )

    1990-05-01

    A deep-sea coral was studied to determine its growth rate and to reconstruct time histories of isotope distributions in the deep ocean. The specimen was collected at a depth of 600 m off Little Bahama Banks using the Deep Submergence Vehicle (DSV) Alvin. The growth rate of the calcitic coral trunk was determined using excess {sup 210}Pb measured in concentric bands. Excess {sup 210}Pb was found in the outer half of the coral's radius, and a growth rate of 0.11 {plus minus} 0.02 mm/a is calculated. Assuming a constant growth rate during formation of the entire trunk, an age of 180 {plus minus} 40 a is estimated for the coral. The decrease observed in radiocarbon activities measured on the same bands (Griffin and Druffel, 1989) concurred with the growth rate estimated from excess {sup 210}Pb activity. {sup 239,240}Pu activities measured by mass spectrometry were also detected in the outer two bands of the coral, as expected from the {sup 210}Pb chronology. Stable oxygen and carbon isotopes measured in samples collected by a variety of techniques are positively correlated. This is evidence of a variable kinetic isotope effect most likely caused by variations in the skeletal growth rate. Long-lived corals such as this specimen have the potential for serving as integrators of seawater chemistry in the deep-sea over several century timescales.

  5. Delivery of unprecedented amounts of perfluoroalkyl substances towards the deep-sea.

    PubMed

    Sanchez-Vidal, Anna; Llorca, Marta; Farré, Marinella; Canals, Miquel; Barceló, Damià; Puig, Pere; Calafat, Antoni

    2015-09-01

    The finding of perfluoroalkyl substances (PFASs) in particles sinking to the deep northwestern Mediterranean Sea confirms the role of the latter as ballast for the transfer of pollutants to the deep sea. The transfer of particulate matter down to the deep is enhanced during atmosphere-driven, high-energy physical oceanographic processes like dense shelf water cascading (DSWC), which is caused by winter surface heat losses and evaporation. Here we present data from samples collected during winter 2012, when dense shelf water formation and subsequent cascading triggered the flushing of large amounts of PFASs through a submarine canyon to depths in excess of 1000 m. The finding of quantifiable concentrations of long-chain PFOA, PFOS and PFNA substances and significantly high concentrations of the short-chain substances PFHxA and PFBA indicates that these compounds, sorbed onto particulate matter, are quickly and directly transferred to the ocean's interior, thus highlighting the role of DSWC in removing those pollutants from the coastal ocean. Eventually, uncertainties about our results arising from the limited number of samples available are counterbalanced by their intrinsic value as intense DSWC events, like the one in 2012, occur only every 5-7 years in the study area, which seriously restricts sampling opportunities. Our results add PFASs to the list of persistent organic pollutants like polychlorinated biphenyls, chlorobenzenes or polycyclic aromatic hydrocarbons known to be conveyed to the deep marine environment.

  6. Zonation of Microbial Communities by a Hydrothermal Mound in the Atlantis II Deep (the Red Sea)

    PubMed Central

    Wang, Yong; Li, Jiang Tao; He, Li Sheng; Yang, Bo; Gao, Zhao Ming; Cao, Hui Luo; Batang, Zenon; Al-Suwailem, Abdulaziz; Qian, Pei-Yuan

    2015-01-01

    In deep-sea geothermal rift zones, the dispersal of hydrothermal fluids of moderately-high temperatures typically forms subseafloor mounds. Major mineral components of the crust covering the mound are barite and metal sulfides. As a result of the continental rifting along the Red Sea, metalliferous sediments accumulate on the seafloor of the Atlantis II Deep. In the present study, a barite crust was identified in a sediment core from the Atlantis II Deep, indicating the formation of a hydrothermal mound at the sampling site. Here, we examined how such a dense barite crust could affect the local environment and the distribution of microbial inhabitants. Our results demonstrate distinctive features of mineral components and microbial communities in the sediment layers separated by the barite crust. Within the mound, archaea accounted for 65% of the community. In contrast, the sediments above the barite boundary were overwhelmed by bacteria. The composition of microbial communities under the mound was similar to that in the sediments of the nearby Discovery Deep and marine cold seeps. This work reveals the zonation of microbial communities after the formation of the hydrothermal mound in the subsurface sediments of the rift basin. PMID:26485717

  7. A multi-locus analysis of phylogenetic relationships within cheilostome bryozoans supports multiple origins of ascophoran frontal shields.

    PubMed

    Knight, Sarah; Gordon, Dennis P; Lavery, Shane D

    2011-11-01

    Phylogenetic relationships within the bryozoan order Cheilostomata are currently uncertain, with many morphological hypotheses proposed but scarcely tested by independent means of molecular analysis. This research uses DNA sequence data across five loci of both mitochondrial and nuclear origin from 91 species of cheilostome Bryozoa (34 species newly sequenced). This vastly improved the taxonomic coverage and number of loci used in a molecular analysis of this order and allowed a more in-depth look into the evolutionary history of Cheilostomata. Maximum likelihood and Bayesian analyses of individual loci were carried out along with a partitioned multi-locus approach, plus a range of topology tests based on morphological hypotheses. Together, these provide a comprehensive set of phylogenetic analyses of the order Cheilostomata. From these results inferences are made about the evolutionary history of this order and proposed morphological hypotheses are discussed in light of the independent evidence gained from the molecular data. Infraorder Ascophorina was demonstrated to be non-monophyletic, and there appears to be multiple origins of the ascus and associated structures involved in lophophore extension. This was further supported by the lack of monophyly within each of the four ascophoran grades (acanthostegomorph/spinocystal, hippothoomorph/gymnocystal, umbonulomorph/umbonuloid, lepraliomorph/lepralioid) defined by frontal-shield morphology. Chorizopora, currently classified in the ascophoran grade Hippothoomorpha, is phylogenetically distinct from Hippothoidae, providing strong evidence for multiple origins of the gymnocystal frontal shield type. Further evidence is produced to support the morphological hypothesis of multiple umbonuloid origins of lepralioid frontal shields, using a step-wise set of topological hypothesis tests combined with examination of multi-locus phylogenies.

  8. Unravelling the Molecular Epidemiology and Genetic Diversity among Burkholderia pseudomallei Isolates from South India Using Multi-Locus Sequence Typing

    PubMed Central

    Shaw, Tushar; KE, Vandana; Kumar, Subodh; Bhat, Vinod; Mukhopadhyay, Chiranjay

    2016-01-01

    There is a slow but steady rise in the case detection rates of melioidosis from various parts of the Indian sub-continent in the past two decades. However, the epidemiology of the disease in India and the surrounding South Asian countries remains far from well elucidated. Multi-locus sequence typing (MLST) is a useful epidemiological tool to study the genetic relatedness of bacterial isolates both with-in and across the countries. With this background, we studied the molecular epidemiology of 32 Burkholderia pseudomallei isolates (31 clinical and 1 soil isolate) obtained during 2006–2015 from various parts of south India using multi-locus sequencing typing and analysis. Of the 32 isolates included in the analysis, 30 (93.7%) had novel allelic profiles that were not reported previously. Sequence type (ST) 1368 (n = 15, 46.8%) with allelic profile (1, 4, 6, 4, 1, 1, 3) was the most common genotype observed. We did not observe a genotypic association of STs with geographical location, type of infection and year of isolation in the present study. Measure of genetic differentiation (FST) between Indian and the rest of world isolates was 0.14413. Occurrence of the same ST across three adjacent states of south India suggest the dispersion of B.pseudomallei across the south western coastal part of India with limited geographical clustering. However, majority of the STs reported from the present study remained as “outliers” on the eBURST “Population snapshot”, suggesting the genetic diversity of Indian isolates from the Australasian and Southeast Asian isolates. PMID:27992477

  9. Terrestrial source to deep-sea sink sediment budgets at high and low sea levels: Insights from tectonically active Southern California

    USGS Publications Warehouse

    Covault, J.A.; Romans, B.W.; Graham, S.A.; Fildani, A.; Hilley, G.E.

    2011-01-01

    Sediment routing from terrestrial source areas to the deep sea influences landscapes and seascapes and supply and filling of sedimentary basins. However, a comprehensive assessment of land-to-deep-sea sediment budgets over millennia with significant climate change is lacking. We provide source to sink sediment budgets using cosmogenic radionuclide-derived terrestrial denudation rates and submarine-fan deposition rates through sea-level fluctuations since oxygen isotope stage 3 (younger than 40 ka) in tectonically active, spatially restricted sediment-routing systems of Southern California. We show that source-area denudation and deep-sea deposition are balanced during a period of generally falling and low sea level (40-13 ka), but that deep-sea deposition exceeds terrestrial denudation during the subsequent period of rising and high sea level (younger than 13 ka). This additional supply of sediment is likely owed to enhanced dispersal of sediment across the shelf caused by seacliff erosion during postglacial shoreline transgression and initiation of submarine mass wasting. During periods of both low and high sea level, land and deep-sea sediment fluxes do not show orders of magnitude imbalances that might be expected in the wake of major sea-level changes. Thus, sediment-routing processes in a globally significant class of small, tectonically active systems might be fundamentally different from those of larger systems that drain entire orogens, in which sediment storage in coastal plains and wide continental shelves can exceed millions of years. Furthermore, in such small systems, depositional changes offshore can reflect onshore changes when viewed over time scales of several thousand years to more than 10 k.y. ?? 2011 Geological Society of America.

  10. Draft Genome Sequence of Deep-Sea Alteromonas sp. Strain V450 Isolated from the Marine Sponge Leiodermatium sp.

    PubMed Central

    Barrett, Nolan H.; McCarthy, Peter J.

    2017-01-01

    ABSTRACT The proteobacterium Alteromonas sp. strain V450 was isolated from the Atlantic deep-sea sponge Leiodermatium sp. Here, we report the draft genome sequence of this strain, with a genome size of approx. 4.39 Mb and a G+C content of 44.01%. The results will aid deep-sea microbial ecology, evolution, and sponge-microbe association studies. PMID:28153886

  11. Comparative genomics reveals a deep-sea sediment-adapted life style of Pseudoalteromonas sp. SM9913

    PubMed Central

    Qin, Qi-Long; Li, Yang; Zhang, Yan-Jiao; Zhou, Zhe-Min; Zhang, Wei-Xin; Chen, Xiu-Lan; Zhang, Xi-Ying; Zhou, Bai-Cheng; Wang, Lei; Zhang, Yu-Zhong

    2011-01-01

    Deep-sea sediment is one of the most important microbial-driven ecosystems, yet it is not well characterized. Genome sequence analyses of deep-sea sedimentary bacteria would shed light on the understanding of this ecosystem. In this study, the complete genome of deep-sea sedimentary bacterium Pseudoalteromonas sp. SM9913 (SM9913) is described and compared with that of the closely related Antarctic surface sea-water ecotype Pseudoalteromonas haloplanktis TAC125 (TAC125). SM9913 has fewer dioxygenase genes than TAC125, indicating a possible sensitivity to reactive oxygen species. Accordingly, experimental results showed that SM9913 was less tolerant of H2O2 than TAC125. SM9913 has gene clusters related to both polar and lateral flagella biosynthesis. Lateral flagella, which are usually present in deep-sea bacteria and absent in the related surface bacteria, are important for the survival of SM9913 in deep-sea environments. With these two flagellar systems, SM9913 can swim in sea water and swarm on the sediment particle surface, favoring the acquisition of nutrients from particulate organic matter and reflecting the particle-associated alternative lifestyle of SM9913 in the deep sea. A total of 12 genomic islands were identified in the genome of SM9913 that may confer specific features unique to SM9913 and absent from TAC125, such as drug and heavy metal resistance. Many signal transduction genes and a glycogen production operon were also present in the SM9913 genome, which may help SM9913 respond to food pulses and store carbon and energy in a deep-sea environment. PMID:20703316

  12. Differences in foraging activity of deep sea diving odontocetes in the Ligurian Sea as determined by passive acoustic recorders

    NASA Astrophysics Data System (ADS)

    Giorli, Giacomo; Au, Whitlow W. L.; Neuheimer, Anna

    2016-01-01

    Characterizing the trophic roles of deep-diving odontocete species and how they vary in space and time is challenged by our ability to observe foraging behavior. Though sampling methods are limited, foraging activity of deep-diving odontocetes can be monitored by recording their biosonar emissions. Daily occurrence of echolocation clicks was monitored acoustically for five months (July-December 2011) in the Ligurian Sea (Mediterranean Sea) using five passive acoustic recorders. Detected odontocetes included Cuvier's beaked whales (Zipuhius cavirostris), sperm whales (Physeter macrocephalus), Risso's dolphins (Grampus griseus), and long-finned pilot whales (Globicephala melas). The results indicated that the foraging strategies varied significantly over time, with sperm whales switching to nocturnal foraging in late September whereas Risso's dolphins and pilot whales foraged mainly at night throughout the sampling period. In the study area, winter nights are about five hours longer than summer nights and an analysis showed that pilot whales and Risso's dolphins adjusted their foraging activity with the length of the night, foraging longer during the longer winter nights. This is the first study to show that marine mammals exhibit diurnal foraging patterns closely correlated to sunrise and sunset.

  13. Pyrosequencing analysis of microbial communities reveals dominant cosmopolitan phylotypes in deep-sea sediments of the eastern Mediterranean Sea.

    PubMed

    Polymenakou, Paraskevi N; Christakis, Christos A; Mandalakis, Manolis; Oulas, Anastasis

    2015-06-01

    The deep eastern basin of the Mediterranean Sea is considered to be one of the world's most oligotrophic areas in the world. Here we performed pyrosequenicng analysis of bacterial and archaeal communities in oxic nutrient-poor sediments collected from the eastern Mediterranean at 1025-4393 m depth. Microbial communities were surveyed by targeting the hypervariable V5-V6 regions of the 16S ribosomal RNA gene using bar-coded pyrosequencing. With a total of 13,194 operational taxonomic units (OTUs) or phylotypes at 97% sequence similarities, the phylogenetic affiliation of microbes was assigned to 23 bacterial and 2 archaeal known phyla, 23 candidate divisions at the phylum level and distributed into 186 families. It was further revealed that the microbial consortia inhabiting all sampling sites were highly diverse, but dominated by phylotypes closely related to members of the genus Pseudomonas and Marine Group I archaea. Such pronounced and widespread enrichment probably manifests the cosmopolitan character of these species and raises questions about their metabolic adaptation to the physical stressors and low nutrient availability of the deep eastern Mediterranean Sea.

  14. The snails' tale at deep-sea habitats in the Gulf of Cadiz (NE Atlantic)

    NASA Astrophysics Data System (ADS)

    Génio, L.; Warén, A.; Matos, F. L.; Cunha, M. R.

    2013-02-01

    Bridging the Atlantic and Mediterranean continental margins, the South Iberian region has recently been the focus for geological and biological investigations. The Gulf of Cadiz (GoC) encompasses a great variety of deep-sea habitats that harbour highly diverse biological communities. In this study, we describe the taxa composition of gastropod assemblages from deep-sea habitats in the GoC and analyse the species distributional patterns in relation to their dispersal capabilities and substrate availability. Distinct gastropod assemblages were found at mud volcanoes, carbonate and coral sites, and organic-falls. Overall, the GoC comprises a high diversity of gastropods that include 65 taxa representing 32 families, 48 genera and 30 named species. The highest number of taxa was found at the highly heterogeneous carbonate province in the middle slope (500-1500 m depth), and higher abundance of individuals was observed in Captain Arutyunov mud volcano, one of the most active sites found in the GoC. Faunal similarities were found with Mediterreanean cold-seeps (species- and genus-level) and other chemosynthetic environments in the Atlantic and Pacific Oceans (genus-level). Colonization experiments with organic substrata (wo