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Sample records for inland hypersaline lakes

  1. Phylogenetic appraisal of antagonistic, slow growing actinomycetes isolated from hypersaline inland solar salterns at Sambhar salt Lake, India

    PubMed Central

    Jose, Polpass Arul; Jebakumar, Solomon Robinson David

    2013-01-01

    Inland solar salterns established in the vicinity of Sambhar Lake are extreme saline environments with high salinity and alkalinity. In view of the fact that microbes inhabiting such extreme saline environments flourish the contemporary bioprospecting, it was aimed to selectively isolate slow growing and rare actinomycetes from the unexplored solar salterns. A total of 14 slow growing actinomycetes were selectively isolated from three composite soil samples of inland solar salterns. Among the isolates, four groups were formed according to similarity of the banding patterns obtained by amplified ribosomal DNA restriction analysis (ARDRA). A subset of representative isolates for each ARDRA group was identified using 16S rDNA sequence based phylogenetic analysis and subsequently the entire isolates were assigned under three different genera; Streptomyces, Pseudonocardia, and Actinoalloteichus. The genus Streptomyces was found to be the dominant among the isolates. Furthermore, rare actinomycete genus Actinoalloteichus was isolated for the first time from solar saltern. Determination of salt-tolerance revealed that certain level of salt-tolerance and moderate halophilism occurs among the actinomycetes isolated from the inland salterns. In addition, all the acinomycetes were screened in two levels to unravel their ability to produce antimicrobial compounds. Significant antimicrobial activity was found among the actinomycetes against a range of bacteria and fungi to worth further characterization of these persuasive actinomycetes and their antimicrobial secondary metabolites. In a nutshell, this study offered a first interesting insight on occurrence of antagonistic rare actinomycetes and streptomycetes in inland solar salterns associated with Sambhar salt Lake. PMID:23847611

  2. Inland hypersaline lakes and the brine shrimp Artemia as simple models for biodiversity analysis at the population level

    PubMed Central

    Gajardo, Gonzalo M; Sorgeloos, Patrick; Beardmore, John A

    2006-01-01

    Biodiversity can be measured at different hierarchical levels, from genetic diversity within species to diversity of ecosystems, though policy-makers tend to use species richness. The 2010 goal of reducing biodiversity loss, agreed by the subscribers to the Convention on Biological Diversity, requires simple and reliable protocols to evaluate biodiversity at any level in a given ecosystem. Stakeholders, particularly policy makers, need to understand how ecosystem components interact to produce social and economic benefits on the long run, whilst scientists are expected to fulfil this demand by testing and modelling ideally simple (low diversity) ecosystems, and by monitoring key species. This work emphasizes the unique opportunity offered by inland, isolated salt lakes and the brine shrimp Artemia, an example of biodiversity contained at the intra-specific level, as simple models to understand and monitor biodiversity, as well as to assess its predicted positive association with ecosystem stability. In addition to having well identified species and strains and even clones, that allow to test reproductive effects (sexual versus asexual), Artemia benefits from the possibility to set up experimental testing at both laboratory scale and outdoor pond systems, for which a comprehensive cyst bank with sufficient amount of samples from all over the world is available. PMID:17132175

  3. Trophic status of inland lakes from LANDSAT

    NASA Technical Reports Server (NTRS)

    Fisher, L. T.; Scarpace, F. L.

    1975-01-01

    A first-cut assessment of the trophic status of inland lakes in Wisconsin was obtained from LANDSAT data. To satisfy the criteria of the project, a large and versatile computer program was developed to gain access to LANDSAT data. This analysis technique has proven to be a cost-effective method of classifying inland lakes in Wisconsin.

  4. Microbial response to salinity change in Lake Chaka, a hypersaline lake on Tibetan plateau.

    PubMed

    Jiang, Hongchen; Dong, Hailiang; Yu, Bingsong; Liu, Xinqi; Li, Yiliang; Ji, Shanshan; Zhang, Chuanlun L

    2007-10-01

    Previous investigations of the salinity effects on the microbial community composition have largely been limited to dynamic estuaries and coastal solar salterns. In this study, the effects of salinity and mineralogy on microbial community composition was studied by using a 900-cm sediment core collected from a stable, inland hypersaline lake, Lake Chaka, on the Tibetan Plateau, north-western China. This core, spanning a time of 17,000 years, was unique in that it possessed an entire range of salinity from freshwater clays and silty sands at the bottom to gypsum and glauberite in the middle, to halite at the top. Bacterial and archaeal communities were studied along the length of this core using an integrated approach combining mineralogy and geochemistry, molecular microbiology (16S rRNA gene analysis and quantitative polymerase chain reaction), cultivation and lipid biomarker analyses. Systematic changes in microbial community composition were correlated with the salinity gradient, but not with mineralogy. Bacterial community was dominated by the Firmicutes-related environmental sequences and known species (including sulfate-reducing bacteria) in the freshwater sediments at the bottom, but by halophilic and halotolerant Betaproteobacteria and Bacteroidetes in the hypersaline sediments at the top. Succession of proteobacterial groups along the salinity gradient, typically observed in free-living bacterial communities, was not observed in the sediment-associated community. Among Archaea, the Crenarchaeota were predominant in the bottom freshwater sediments, but the halophilic Halobacteriales of the Euryarchaeota was the most important group in the hypersaline sediments. Multiple isolates were obtained along the whole length of the core, and their salinity tolerance was consistent with the geochemical conditions. Iron-reducing bacteria were isolated in the freshwater sediments, which were capable of reducing structural Fe(III) in the Fe(III)-rich clay minerals

  5. Multi-temporal water extent analysis of a hypersaline playa lake using Landsat Imagery

    NASA Astrophysics Data System (ADS)

    Kilic, Ecenur; Kamil Yilmaz, Koray; Lutfi Suzen, Mehmet

    2016-04-01

    Distinguishing inland water bodies from satellite imagery has always been one of the main practices of remote sensing. In some cases this differentiation can directly be obtained by visual interpretation. However, in case of hyper-saline playa lakes, presence of high albedo salt crust in the lake bed hampers visual interpretation and requires further attention. Lake Tuz is a hypersaline playa lake which is ranked as the second largest lake in Turkey. Spatio-temporal changes in lake water extent are important both economically and hydrologically including salt production, lake water balance, drought and over-exploitation issues. This study investigates the spatiotemporal changes in Lake Tuz water extent during the last decade using single-band thresholding and multi-band indices extracted from the multi-temporal Landsat 5 TM and Landsat 7 ETM+ images. The applicability of different satellite-derived indices including Normalized Difference Water Index (NDWI), Modified NDWI (MNDWI), Automated Water Extraction Index (AWEI) and Tasseled Cap Wetness (TCw) were investigated for the extraction of lake water extent from Landsat imagery. Our analysis indicated that, overall, NDWI is superior to other tested indices in separating wet/dry pixels over the lake bottom covered with salt crust. Using a NDWI thresholding procedure, the annual and seasonal variation in the Lake Tuz water extent were determined and further linked to hydro-meteorological variables such as precipitation.

  6. Bacterial Dormancy Is More Prevalent in Freshwater than Hypersaline Lakes

    PubMed Central

    Aanderud, Zachary T.; Vert, Joshua C.; Lennon, Jay T.; Magnusson, Tylan W.; Breakwell, Donald P.; Harker, Alan R.

    2016-01-01

    Bacteria employ a diverse array of strategies to survive under extreme environmental conditions but maintaining these adaptations comes at an energetic cost. If energy reserves drop too low, extremophiles may enter a dormant state to persist. We estimated bacterial dormancy and identified the environmental variables influencing our activity proxy in 10 hypersaline and freshwater lakes across the Western United States. Using ribosomal RNA:DNA ratios as an indicator for bacterial activity, we found that the proportion of the community exhibiting dormancy was 16% lower in hypersaline than freshwater lakes. Based on our indicator variable multiple regression results, saltier conditions in both freshwater and hypersaline lakes increased activity, suggesting that salinity was a robust environmental filter structuring bacterial activity in lake ecosystems. To a lesser degree, higher total phosphorus concentrations reduced dormancy in all lakes. Thus, even under extreme conditions, the competition for resources exerted pressure on activity. Within the compositionally distinct and less diverse hypersaline communities, abundant taxa were disproportionately active and localized in families Microbacteriaceae (Actinobacteria), Nitriliruptoraceae (Actinobacteria), and Rhodobacteraceae (Alphaproteobacteria). Our results are consistent with the view that hypersaline communities are able to capitalize on a seemingly more extreme, yet highly selective, set of conditions and finds that extremophiles may need dormancy less often to thrive and survive. PMID:27375575

  7. USEPA Inland HAB Risk Management - Lake Harsha

    EPA Science Inventory

    Freshwater inland lakes and reservoirs supply approximately 70% of the nation’s drinking water and industrial needs. These are typically open ecological systems and susceptible to Harmful algal blooms (HABs) which are increasing in frequency, intensity, and geographic range. I...

  8. USEPA Inland HAB Risk Management - Lake Harsha

    EPA Science Inventory

    Freshwater inland lakes and reservoirs supply approximately 70% of the nation’s drinking water and industrial needs. These are typically open ecological systems and susceptible to Harmful algal blooms (HABs) which are increasing in frequency, intensity, and geographic range. I...

  9. Uranium Geochemistry in Hypersaline Soda Lakes in Eastern Mongolia

    NASA Astrophysics Data System (ADS)

    Linhoff, B. S.; Bennett, P.; Puntsag, T.

    2007-12-01

    Extremely high concentrations of uranium were discovered in water samples from hypersaline soda lakes in eastern Mongolia. The origin and fate of uranium in these lakes was examined using geochemical analyses and modeling, using samples collected from five lakes, six wells and one stream. Samples were analyzed for strontium and uranium isotopes, cations and trace metals, anions, alkalinity, and unstable field parameters. The lakes are small, shallow (<1Km2, <1m) and terminal; their size fluctuates seasonally and they periodically completely desiccate. The region is characterized by rolling semi arid grassland steppe covered by a thick loess deposit of unknown thickness that is underlain by Neogene rhyolite. A typical groundwater in the field area is alkaline (pH = 7.9, 10.7 meq alk/L), 4.4 ° C, with an average T.D.S. of 1500 and low calcium concentration (20 ppm). A strong linear correlation was found between groundwater and lake water chlorine to bromine ratios implying groundwater discharges to lake water and is subsequently evaporated. Evaporation is intense with lake waters having average chlorine concentrations 300 times that of well waters. Uranium in well samples is higher than typical for shallow groundwaters (7-101ppb) suggesting discharging groundwater as a probable source of uranium in lake water. Concentrations of uranium in lake water ranges from 57-14,900ppb making these lakes possibly the highest naturally occurring uranium concentration reported. Lake water alkalinity is strongly correlated to uranium abundance suggesting uranium is complexed with carbonate as the aqueous species UO2CO3. Consequently, the extremely high alkalinity of the most alkaline lake (pH = 9.8, 1288.8 meq alk/L) also has the highest uranium concentrations. Stable strontium isotopes were used to assess the degree of water rock interactions and the presence of 90Sr was checked for to test the possibility of input of nuclear fallout. 90Sr was not detected in lake water samples

  10. Geo- and Biogeochemical Processes in a Heliothermal Hypersaline Lake

    SciTech Connect

    Zachara, John M.; Moran, James J.; Resch, Charles T.; Lindemann, Stephen R.; Felmy, Andrew R.; Bowden, Mark E.; Cory, Alexandra B.; Fredrickson, Jim K.

    2016-03-17

    Water chemical variations were investigated over three annual hydrologic cycles in hypersaline, heliothermal, meromictic Hot Lake in north-central Washington State, USA. The lake, originally studied by Anderson (1958), contains diverse biota with dramatic zonation related to salinity and redox state. Water samples were collected at 10 cm depth intervals through the shallow lake (2.4 m) at a consistent location during 2012-2014, with comprehensive monitoring performed in 2013. Inorganic salt species, total dissolved solids (TDS), dissolved carbon forms (DOC, DIC), oxygen, sulfide, and methane were analyzed in lake water samples. Depth sonde measurements of pH and temperature were also performed to track their seasonal variations. A bathymetric survey of the lake was conducted to enable lake water volume and solute inventory calculations. Sediment cores were collected at low water and analyzed by x-ray diffraction to investigate sediment mineralogy. The primary dissolved salt in Hot Lake water was Mg2+-SO42- while sediments were dominated by gypsum (CaSO4•2H2O). Lake water concentrations increased with depth to reach saturation with epsomite that was exposed at lake bottom. At maximum volume in spring, Hot Lake exhibited a relatively dilute mixolimnion containing phyto- and zooplankton; a lower saline metalimnion with stratified oxygenic and anoxygenic photosynthetic microbiologic communities; and a stable, hypersaline monimolimnion, separated from above layers by a chemocline, containing high levels of sulfide and methane. The thickness of the mixolimnion regulates a heliothermal effect which creates temperatures in excess of 60 oC in the underlying metalimnion and monimolimnion. The mixolimnion was dynamic and actively mixed. It displayed large pH variations, in-situ calcium carbonate precipitation, and large evaporative volume losses. The depletion of this ephemeral layer by fall allowed deeper mixing into the volume-stable lower mixolimnion, more rapid heat

  11. Geo- and biogeochemical processes in a heliothermal hypersaline lake

    NASA Astrophysics Data System (ADS)

    Zachara, John M.; Moran, James J.; Resch, Charles T.; Lindemann, Stephen R.; Felmy, Andrew R.; Bowden, Mark E.; Cory, Alexandra B.; Fredrickson, James K.

    2016-05-01

    Water chemical variations were investigated over three annual hydrologic cycles in hypersaline, heliothermal, meromictic Hot Lake in north-central Washington State, USA. The lake contains diverse biota with dramatic zonation related to salinity and redox state. Water samples were collected at 10-cm depth intervals through the shallow lake (2.4 m) during 2012-2014, with comprehensive monitoring performed in 2013. Inorganic salt species, dissolved carbon forms (DOC, DIC), oxygen, sulfide, and methane were analyzed in lake water samples. Depth sonde measurements of pH and temperature were also performed to track their seasonal variations. A bathymetric survey of the lake was conducted to enable lake water volume and solute inventory calculations. Sediment cores were collected at low water and analyzed by X-ray diffraction to investigate sediment mineralogy. The primary dissolved salt in Hot Lake water was Mg2+-SO42- whereas sediments were dominated by gypsum (CaSO4·2H2O). Lake water concentrations increased with depth, reaching saturation with epsomite (MgSO4·7H2O) that was exposed at lake bottom. At maximum volume in spring, Hot Lake exhibited a relatively dilute mixolimnion; a lower saline metalimnion with stratified oxygenic and anoxygenic photosynthetic microbiological communities; and a stable, hypersaline monimolimnion, separated from above layers by a chemocline, containing high levels of sulfide and methane. The thickness of the mixolimnion regulates a heliothermal effect that creates temperatures in excess of 60 °C in the underlying metalimnion and monimolimnion. The mixolimnion was dynamic in volume and actively mixed. It displayed large pH variations, in-situ calcium carbonate precipitation, and large evaporative volume losses. The depletion of this layer by fall allowed deeper mixing into the metalimnion, more rapid heat exchange, and lower winter lake temperatures. Solubility calculations indicate seasonal biogenic and thermogenic aragonite

  12. Microbial diversity in the hypersaline Lake Meyghan, Iran.

    PubMed

    Naghoni, Ali; Emtiazi, Giti; Amoozegar, Mohammad Ali; Cretoiu, Mariana Silvia; Stal, Lucas J; Etemadifar, Zahra; Shahzadeh Fazeli, Seyed Abolhassan; Bolhuis, Henk

    2017-09-14

    Lake Meyghan is one of the largest and commercially most important salt lakes in Iran. Despite its inland location and high altitude, Lake Meyghan has a thalassohaline salt composition suggesting a marine origin. Inputs of fresh water by rivers and rainfall formed various basins characterized by different salinities. We analyzed the microbial community composition of three basins by isolation and culturing of microorganisms and by analysis of the metagenome. The basins that were investigated comprised a green ~50 g kg(-1) salinity brine, a red ~180 g kg(-1) salinity brine and a white ~300 g kg(-1) salinity brine. Using different growth media, 57 strains of Bacteria and 48 strains of Archaea were isolated. Two bacterial isolates represent potential novel species with less than 96% 16S rRNA gene sequence identity to known species. Abundant isolates were also well represented in the metagenome. Bacteria dominated the low salinity brine, with Alteromonadales (Gammaproteobacteria) as a particularly important taxon, whereas the high salinity brines were dominated by haloarchaea. Although the brines of Lake Meyghan differ in geochemical composition, their ecosystem function appears largely conserved amongst each other while being driven by different microbial communities.

  13. Authigenic carbonate precipitation in Lake Acigöl, a hypersaline lake in southwestern Turkey

    NASA Astrophysics Data System (ADS)

    Balci, Nurgul; Menekse, Meryem; Gül Karagüler, Nevin; Seref Sönmez, M.; Meister, Patrick

    2014-05-01

    Lake Acigöl (Bitter Lake) is a hypersaline lake in southwestern Turkey at an elevation of 836 m above sea level showing authigenic precipitation of several different carbonate mineral phases. It is a perennial lake and closed drainage basin where a semiarid continental climate dominates. Due to the extreme water chemistry (salinity 8-200 mg/l; SO4 112-15232 mg/l; Cl 290-35320 mg/l; Mg, 82-3425 mg/l; Ca 102-745 mg/l) unique microorganisms flourish in the lake. We studied microbial diversity from enrichment cultures and performed precipitation experiments using similar water chemistry and adding bacterial enrichment cultures from lake sediments in order to elucidate whether the mineral assemblages found in the lake can be reproduced. Experiments using moderately halophilic bacteria obtained from the lake sediments demonstrate the formation of various calcium-/magnesium-carbonates: hydromagnesite, dypingite, huntite, monohydrocalcite and aragonite. The relative amounts of different mineral phases, particularly monohydrocalcite, hydromagnesite and dypingite, could be controlled by varying the sulphate concentration in the media from 0 to 56 mM. The similar mineral assemblages identified in the sediments of Lake Acigöl and in the experiments point to similar thermodynamic conditions and kinetics of crystal growth. In particular, the similar spherical morphology points to a rapid crystal growth under strong kinetic inhibition, possibly by organic polymers that are commonly produced by microbial communities. Our results demonstrate that the authigenic carbonate paragenesis of hypersaline lakes as Lake Acigöl can be reproduced in halophilic bacterial cultures. The exact thermodynamic conditions and precipitation kinetics under seasonally changing water chemistry or in batch experiment, however, still have to be constrained in order to establish a microbial model for carbonate precipitation in such environments.

  14. 46 CFR 11.430 - Endorsements for the Great Lakes and inland waters.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Endorsements for the Great Lakes and inland waters. 11... Endorsements for the Great Lakes and inland waters. Any license or MMC endorsement issued for service on the Great Lakes and inland waters is valid on all of the inland waters of the United States as defined in...

  15. 46 CFR 11.430 - Endorsements for the Great Lakes and inland waters.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Endorsements for the Great Lakes and inland waters. 11... Endorsements for the Great Lakes and inland waters. Any license or MMC endorsement issued for service on the Great Lakes and inland waters is valid on all of the inland waters of the United States as defined in...

  16. 46 CFR 11.430 - Endorsements for the Great Lakes and inland waters.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Endorsements for the Great Lakes and inland waters. 11... Endorsements for the Great Lakes and inland waters. Any license or MMC endorsement issued for service on the Great Lakes and inland waters is valid on all of the inland waters of the United States as defined in...

  17. 46 CFR 11.430 - Endorsements for the Great Lakes and inland waters.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Endorsements for the Great Lakes and inland waters. 11... Endorsements for the Great Lakes and inland waters. Any license or MMC endorsement issued for service on the Great Lakes and inland waters is valid on all of the inland waters of the United States as defined in...

  18. Characterization of eukaryotic microbial diversity in hypersaline Lake Tyrrell, Australia

    PubMed Central

    Heidelberg, Karla B.; Nelson, William C.; Holm, Johanna B.; Eisenkolb, Nadine; Andrade, Karen; Emerson, Joanne B.

    2013-01-01

    This study describes the community structure of the microbial eukaryotic community from hypersaline Lake Tyrrell, Australia, using near full length 18S rRNA sequences. Water samples were taken in both summer and winter over a 4-year period. The extent of eukaryotic diversity detected was low, with only 35 unique phylotypes using a 97% sequence similarity threshold. The water samples were dominated (91%) by a novel cluster of the Alveolate, Apicomplexa Colpodella spp., most closely related to C. edax. The Chlorophyte, Dunaliella spp. accounted for less than 35% of water column samples. However, the eukaryotic community entrained in a salt crust sample was vastly different and was dominated (83%) by the Dunaliella spp. The patterns described here represent the first observation of microbial eukaryotic dynamics in this system and provide a multiyear comparison of community composition by season. The lack of expected seasonal distribution in eukaryotic communities paired with abundant nanoflagellates suggests that grazing may significantly structure microbial eukaryotic communities in this system. PMID:23717306

  19. Prokaryotic diversity in a Tunisian hypersaline lake, Chott El Jerid.

    PubMed

    Abdallah, Manel Ben; Karray, Fatma; Mhiri, Najla; Mei, Nan; Quéméneur, Marianne; Cayol, Jean-Luc; Erauso, Gaël; Tholozan, Jean-Luc; Alazard, Didier; Sayadi, Sami

    2016-03-01

    Prokaryotic diversity was investigated in a Tunisian salt lake, Chott El Jerid, by quantitative real-time PCR, denaturing gradient gel electrophoresis (DGGE) fingerprinting methods targeting the 16S rRNA gene and culture-dependent methods. Two different samples S1-10 and S2-10 were taken from under the salt crust of Chott El Jerid in the dry season. DGGE analysis revealed that bacterial sequences were related to Firmicutes, Proteobacteria, unclassified bacteria, and Deinococcus-Thermus phyla. Anaerobic fermentative and sulfate-reducing bacteria were also detected in this ecosystem. Within the domain archaea, all sequences were affiliated to Euryarchaeota phylum. Quantitative real-time PCR showed that 16S rRNA gene copy numbers of bacteria was 5 × 10(6) DNA copies g(-1) whereas archaea varied between 5 × 10(5) and 10(6) DNA copies g(-1) in these samples. Eight anaerobic halophilic fermentative bacterial strains were isolated and affiliated with the species Halanaerobium alcaliphilum, Halanaerobium saccharolyticum, and Sporohalobacter salinus. These data showed an abundant and diverse microbial community detected in the hypersaline thalassohaline environment of Chott El Jerid.

  20. Calcium Biomineralization in Sediment of Lake Acigol, an Hypersaline Lake in SW Turkey

    NASA Astrophysics Data System (ADS)

    Celik Balci, Nurgul; Menekse, Meryem; Sonmez, Seref; Gul Karaguler, Nevin

    2010-05-01

    The study of biomineralization in (hyper) saline environments is important for two reasons, 1-it can extend our knowledge about the earliest microbial life on Earth which may have been halophilic 2-because of the presence of hypersaline conditions on Mars, the analog environments in Earth may have implications for the possibility of life on Mars. We examine calcium biomineralization in Lake Acigol, a unique hypersaline lake in southwest Turkey by integrating geochemical and microbiological approaches. Lake Acigol is a perennial lake with a maximum salinity of about 200 g/L and covers an area of 55-60 km2and is one of the main salt reservoirs of Turkey. Water, sediment and core samples were taken from the lake and salty ponds around the lake during the field excursion. The water chemistry revealed relatively high Na and SO4 concentrations both in the lake (30 gr/L, 33.36 gr/L), and the ponds (100 mg/L, 123 mg/L). The mineralogical analyses of sediments showed gypsum, halite, carbonate (aragonite, huntite) precipitation in the lake and ponds. We employed culture-dependent (16s rRNA cloning method, enrichment culture), and -independent techniques to study microbial diversity in Lake Aci gol. Sediment samples were used to isolate Halophilic sp. (e.g. salinicoccus roseus , Dunella sp.) under salinities that were similar to those measured in the lake water to further use in the laboratory Ca-precipitation experiments. For the precipitation experiments, liquid and solid culture media with various salinities ( 6-25 %) in addition to one similar to the lake water were prepared. In order to determine effect of Mg2+-Ca2+ molar ratio on mineralogy and the rate of precipitation, media with different Ca2+and Mg2+ concentrations were also prepared. Our preliminary results indicate that the halophilic bacteria play active role in the precipitation of Ca-minerals but the geochemical conditions are clearly influential. The results also point out that in the Lake Aci gol C, N, P, Ca

  1. Brackish to hypersaline lake dolostones of the Mississippian

    NASA Astrophysics Data System (ADS)

    Bennett, Carys; Kearsey, Timothy; Davies, Sarah; Millward, David; Marshall, John

    2016-04-01

    , and 9% of all dolostone beds in the Norham Core are pedogenically altered. The isotopic composition of dolomite beds is δ18O -3.6‰ to -1.7‰ and δ13C -2.6‰ to 1.6‰ which is consistent with a brackish as opposed to marine origin. The dolostones are categorised by their sedimentary composition: Facies 1: Cemented siltstone and sandstone; Facies 2: Homogeneous micrite to micro-crystaline dolomite, within a clay matrix; Facies 3: Bedded dolomite and siltstone; Facies 4: Mixed calcite and dolomite; Facies 5: Dolomite with gypsum and anhydrite. Formation processes are diverse, and include diagenetic cementation (Facies 1), deposition in saline (brackish) lakes (Facies 2), deposition in saline lakes with clastic sediment input (Facies 3), lagoonal to shallow-marine carbonate deposition (Facies 4), and hypersaline lake to sabkha environments (Facies 5). 60% of the beds are facies 2 or 3 and their sedimentology, fauna, ichnofauna and isotopic composition indicate a brackish-water origin. Other Mississippian dolostones from around the world also contain a fairly restricted fauna and have been interpreted as brackish water deposits. The mechanism of dolomite formation under these conditions is discussed. These dolostones provided extensive coastal lakes that may have been an important habitat for tetrapods and other transitional groups during the Mississippian.

  2. Anaerobic Halo-Alkaliphilic Baterial Community of Athalassic, Hypersaline Mono Lake in California

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena V.; Hoover, Richard B.; Marsic, Damien; Ng, Joseph D.; Six, N. Frank (Technical Monitor)

    2002-01-01

    The microorganisms of soda Mono Lake and other similar athalassic hypersaline alkaline soda lakes are of significance to Astrobiology. The microorganisms of these regimes represent the best known terrestrial analogs for microbial life that might have inhabited the hypersaline alkaline lakes and evaporites confined within closed volcanic basins and impact craters during the late Noachian and early Hesperian epochs (3.6 - 4.2 Gya) of ancient Mars. We have investigated the anaerobic microbiota of soda Mono Lake in northern California. In this paper we discuss the astrobiological significance of these ecosystems and describe several interesting features of two novel new species of anaerobic halo-alkaliphilic bacteria (Spirochaeta americana, sp. nov. and Desulfonatronum paiuteum, sp. nov) that we have isolated from Mono Lake.

  3. Anaerobic Halo-Alkaliphilic Baterial Community of Athalassic, Hypersaline Mono Lake in California

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena V.; Hoover, Richard B.; Marsic, Damien; Ng, Joseph D.; Six, N. Frank (Technical Monitor)

    2002-01-01

    The microorganisms of soda Mono Lake and other similar athalassic hypersaline alkaline soda lakes are of significance to Astrobiology. The microorganisms of these regimes represent the best known terrestrial analogs for microbial life that might have inhabited the hypersaline alkaline lakes and evaporites confined within closed volcanic basins and impact craters during the late Noachian and early Hesperian epochs (3.6 - 4.2 Gya) of ancient Mars. We have investigated the anaerobic microbiota of soda Mono Lake in northern California. In this paper we discuss the astrobiological significance of these ecosystems and describe several interesting features of two novel new species of anaerobic halo-alkaliphilic bacteria (Spirochaeta americana, sp. nov. and Desulfonatronum paiuteum, sp. nov) that we have isolated from Mono Lake.

  4. 46 CFR 11.430 - Endorsements for the Great Lakes and inland waters.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Endorsements for the Great Lakes and inland waters. 11... Endorsements § 11.430 Endorsements for the Great Lakes and inland waters. (a) Any officer endorsement issued for service on Great Lakes and inland waters self-propelled vessels, excluding towing vessels, is...

  5. Draft Genome Sequence of Pantoea anthophila Strain 11-2 from Hypersaline Lake Laysan, Hawaii.

    PubMed

    Wan, Xuehua; Hou, Shaobin; Phan, Nolwenn; Malone Moss, Jennifer S; Donachie, Stuart P; Alam, Maqsudul

    2015-05-14

    Most Pantoea spp. have been isolated from plant sources or clinical samples. However, we cultivated Pantoea anthophila 11-2 from hypersaline water from the lake on Laysan, Northwestern Hawaiian Islands. Draft genome sequencing of 11-2 provides a molecular basis for studies in evolution and pathogenicity in Pantoea spp. Copyright © 2015 Wan et al.

  6. The contribution of lakes to global inland fisheries harvest

    USGS Publications Warehouse

    Deines, Andrew M.; Bunnell, David B.; Rogers, Mark W.; Bennion, David; Woelmer, Whitney; Sayers, Michael J.; Grimm, Amanda G.; Shuchman, Robert A.; Raymer, Zachary B.; Brooks, Colin N.; Mychek-Londer, Justin G.; Taylor, William W.; Beard, Douglas

    2017-01-01

    Freshwater ecosystems provide numerous services for communities worldwide, including irrigation, hydropower, and municipal water; however, the services provided by inland fisheries – nourishment, employment, and recreational opportunities – are often comparatively undervalued. We provide an independent estimate of global lake harvest to improve biological and socioeconomic assessments of inland fisheries. On the basis of satellite-derived estimates of chlorophyll concentration from 80,012 globally distributed lakes, lake-specific fishing effort based on human population, and output from a Bayesian hierarchical model, we estimated that the global lake fishery harvest in the year 2011 was 8.4 million tons (mt). Our calculations excluded harvests from highly productive rivers, wetlands, and very small lakes; therefore, the true cumulative global fishery harvest from all freshwater sources likely exceeded 11 mt as reported by the Food and Agriculture Organization of the United Nations (FAO). This putative underestimate by the FAO could diminish the perceived importance of inland fisheries and perpetuate decisions that adversely affect these fisheries and millions of people.

  7. Geologically controlled bi-directional exchange of groundwater with a hypersaline lake in the Canadian prairies

    NASA Astrophysics Data System (ADS)

    Bentley, Laurence R.; Hayashi, Masaki; Zimmerman, Elena P.; Holmden, Chris; Kelley, Lynn I.

    2016-06-01

    Hypersaline lakes occur in hydrologically closed basins due to evaporitic enrichment of dissolved salts transported to the lakes by surface water and groundwater. At the hypersaline Lydden Lake in Saskatchewan, Canada, groundwater/lake-water interaction is strongly influenced by the geological heterogeneity of glacial deposits, whereby a highly permeable glaciofluvial sand/gravel deposit is underlain by glaciolacustrine deposits consisting of dense clay interspersed with silt/sand lenses. Pressure head distribution in a near shore area indicates a bi-directional flow system. It consists of topographically driven flow of fresh groundwater towards the lake in the sand/gravel aquifer and density-driven, landward flow of saline groundwater in the underlying glaciolacustrine deposits. Electrical resistivity tomography, and chemical and isotopic composition of groundwater clearly show the landward intrusion of saline water in the heterogeneous unit. The feasibility of bi-directional flow and transport is supported by numerical simulations of density-coupled groundwater flow and transport. The results suggest that the geologically controlled groundwater exchange processes have substantial influences on both inputs and outputs of dissolved minerals in hypersaline lakes in closed basins.

  8. Characterization of basidiomycetous yeasts in hypersaline soils of the Urmia Lake National Park, Iran.

    PubMed

    Mokhtarnejad, Lachin; Arzanlou, Mahdi; Babai-Ahari, Asadollah; Di Mauro, Simone; Onofri, Andrea; Buzzini, Pietro; Turchetti, Benedetta

    2016-11-01

    Urmia Lake, located in northwest Iran, is an oligotrophic and extremely hypersaline habitat that supports diverse forms of life. Owing to its unique biodiversity and special environmental conditions, Urmia Lake National Park has been designated as one of the biosphere reserves by UNESCO. This study was aimed to characterize basidiomycetous yeasts in hypersaline soils surrounding the Urmia Lake National Park using a polyphasic combination of molecular and physiological data. Soil samples were collected from eight sites in Lake Basin and six islands insides the lake. Yeast strains were identified by sequencing the D1/D2 domains of the 26S rRNA gene. When D1/D2 domain sequencing did not resolve the identity of the species, strain identification was obtained by ITS 1 & 2 sequencing. Twenty-one species belonging to the genera Cystobasidium, Holtermanniella, Naganishia, Rhodotorula, Saitozyma, Solicoccozyma, Tausonia, Vanrija, and Vishniacozyma were identified. Solicoccozyma aeria represented the dominant species. The ability of isolates to grow at 10 and 15 % of NaCl was checked; about two-thirds of the strains grew at 10 %, while about 13 % of the isolates grew in medium with 15 % NaCl. this study is the first study on the culturable yeast diversity in hypersaline soils surrounding an Asian lake.

  9. Microbial Diversity in a Hypersaline Sulfate Lake: A Terrestrial Analog of Ancient Mars

    PubMed Central

    Pontefract, Alexandra; Zhu, Ting F.; Walker, Virginia K.; Hepburn, Holli; Lui, Clarissa; Zuber, Maria T.; Ruvkun, Gary; Carr, Christopher E.

    2017-01-01

    Life can persist under severe osmotic stress and low water activity in hypersaline environments. On Mars, evidence for the past presence of saline bodies of water is prevalent and resulted in the widespread deposition of sulfate and chloride salts. Here we investigate Spotted Lake (British Columbia, Canada), a hypersaline lake with extreme (>3 M) levels of sulfate salts as an exemplar of the conditions thought to be associated with ancient Mars. We provide the first characterization of microbial structure in Spotted Lake sediments through metagenomic sequencing, and report a bacteria-dominated community with abundant Proteobacteria, Firmicutes, and Bacteroidetes, as well as diverse extremophiles. Microbial abundance and functional comparisons reveal similarities to Ace Lake, a meromictic Antarctic lake with anoxic and sulfidic bottom waters. Our analysis suggests that hypersaline-associated species occupy niches characterized foremost by differential abundance of Archaea, uncharacterized Bacteria, and Cyanobacteria. Potential biosignatures in this environment are discussed, specifically the likelihood of a strong sulfur isotopic fractionation record within the sediments due to the presence of sulfate reducing bacteria. With its high sulfate levels and seasonal freeze-thaw cycles, Spotted Lake is an analog for ancient paleolakes on Mars in which sulfate salt deposits may have offered periodically habitable environments, and could have concentrated and preserved organic materials or their biomarkers over geologic time.

  10. Microbial Fe cycling and mineralization in sediments of an acidic, hypersaline lake (Lake Tyrell, Victoria, Australia)

    NASA Astrophysics Data System (ADS)

    Roden, E. E.; Blöthe, M.; Shelobolina, E.

    2009-12-01

    Lake Tyrrell is a variably acidic, hypersaline, Fe-rich lake located in Victoria, Australia. Terrestrial acid saline lakes like Lake Tyrrell may be analogs for ancient Martian surface environments, as well as possible extant subsurface environments. To investigate the potential for microbial Fe cycling under acidic conditions and high salt concentration, we collected sediment core samples during three field trips between 2006 and 2008 from the southern, acidic edge of the lake. Materials from the cores were used for chemical and mineralogical analyses, as well as for molecular (16S rRNA genes) and culture-based microbiological studies. Near-surface (< 1 m depth) pore fluids contained low but detectable dissolved oxygen (ca. 50 uM), significant dissolved Fe(II) (ca. 500 uM), and nearly constant pH of around 4 - conditions conducive to enzymatic Fe(II) oxidation. High concentrations of Fe(III) oxides begin accumulate at a depth of ca. 10 cm, and may reflect the starting point for formation of massive iron concretions that are evident at and beneath the sediment surface. MPN analyses revealed low (10-100 cells/mL) but detectable populations of aerobic, halophilic Fe(II)-oxidizing organisms on the sediment surface and in the near-surface ground water. With culture-dependent methods at least three different halotolerant lithoautotrophic cultures growing on Fe(II), thiosulfate, or tetrathionate from different acidic sites were obtained. Analysis of 16S rRNA gene sequences revealed that these organisms are similar to previous described gamma proteobacteria Thiobacillus prosperus (95%), Halothiobacillus kellyi (99%), Salinisphaera shabanense (95%) and a Marinobacter species. (98%). 16S rRNA gene pyrosequencing data from two different sites with a pH range between 3 and 4.5 revealed a dominance of gamma proteobacteria. 16S rRNA gene pyrosequencing libraries from both cores were dominated by sequences related to the Ectothiorhodospiraceae family, which includes the taxa

  11. Climatic change and evaporative processes in the development of Common Era hypersaline lakes, East Antarctica: A study of Lake Suribati

    NASA Astrophysics Data System (ADS)

    Nakashima, H.; Seto, K.; Katsuki, K.; Kaneko, H.; yamada, K.; Imura, S.; Dettman, D. L.

    2011-12-01

    The Antarctic continent was uplifted by glacioisostatic rebound due to the regression of ice sheets after the last glacial period. Today's saline lakes were formed in shallow basins originally below sea level. Antarctic hypersaline lakes are formed by concentration of isolated seawater bodies as affected by recent climate change. Many saline lakes are found in the ice-free area of the Soya coast, East Antarctica. Lake Suribati is located in Sukarvsnes on the Soya coast. It is a hypersaline lake with maximum salinity ~200 psu, and an observable stable halocline at 7~12m depth. This study uses Lake Suribati sediment core Sr4C-01, collected by the 46th Japanese Antarctica Research Expedition, to examine the relationship of climatic change to evaporative processes and solute concentration in Lake Suribati in the Common Era. Sr4C-01 core was collected at 9.53m water depth in Lake Suribati in 2005 (core length is 63cm). This core primarily consists of black mud and laminated black organic mud. In the interval from 10 to 24cm below the sediment surface evaporite crystals occur. The age of the Sr4C-01 core bottom is estimated to be ~3,500 cal yrs BP, based on AMS carbon-14 dating at 6 core horizons. The evaporite crystals were indentified as aragonite based on XRD. Total inorganic carbon (TIC) content is low, around 0.5%, throughout the Sr4C-01 core, with higher values, approximately 1~4%, in two intervals, 57~52cm and 29~10cm core depth. Variation in CaO content tracks TIC content. We suggest that synchronous change in CaO and TIC contents indicate the vertical change in the amount of aragonite. Two intervals of evaporite precipition imply two intervals of evaporation and concentration of lake water. Hypersaline lake conditions did not occur soon after the isolation from the sea, rather these occurred under repeated concentration and dilution of lake water. Dilution of saline lake water could occur through the inflow of melt water from local snow or ice, indicating a warm

  12. Contrasting taxonomic stratification of microbial communities in two hypersaline meromictic lakes

    PubMed Central

    Andrei, Adrian-Ştefan; Robeson, Michael S; Baricz, Andreea; Coman, Cristian; Muntean, Vasile; Ionescu, Artur; Etiope, Giuseppe; Alexe, Mircea; Sicora, Cosmin Ionel; Podar, Mircea; Banciu, Horia Leonard

    2015-01-01

    Hypersaline meromictic lakes are extreme environments in which water stratification is associated with powerful physicochemical gradients and high salt concentrations. Furthermore, their physical stability coupled with vertical water column partitioning makes them important research model systems in microbial niche differentiation and biogeochemical cycling. Here, we compare the prokaryotic assemblages from Ursu and Fara Fund hypersaline meromictic lakes (Transylvanian Basin, Romania) in relation to their limnological factors and infer their role in elemental cycling by matching taxa to known taxon-specific biogeochemical functions. To assess the composition and structure of prokaryotic communities and the environmental factors that structure them, deep-coverage small subunit (SSU) ribosomal RNA (rDNA) amplicon sequencing, community domain-specific quantitative PCR and physicochemical analyses were performed on samples collected along depth profiles. The analyses showed that the lakes harbored multiple and diverse prokaryotic communities whose distribution mirrored the water stratification patterns. Ursu Lake was found to be dominated by Bacteria and to have a greater prokaryotic diversity than Fara Fund Lake that harbored an increased cell density and was populated mostly by Archaea within oxic strata. In spite of their contrasting diversity, the microbial populations indigenous to each lake pointed to similar physiological functions within carbon degradation and sulfate reduction. Furthermore, the taxonomy results coupled with methane detection and its stable C isotope composition indicated the presence of a yet-undescribed methanogenic group in the lakes' hypersaline monimolimnion. In addition, ultrasmall uncultivated archaeal lineages were detected in the chemocline of Fara Fund Lake, where the recently proposed Nanohaloarchaeota phylum was found to thrive. PMID:25932617

  13. Contrasting taxonomic stratification of microbial communities in two hypersaline meromictic lakes.

    PubMed

    Andrei, Adrian-Ştefan; Robeson, Michael S; Baricz, Andreea; Coman, Cristian; Muntean, Vasile; Ionescu, Artur; Etiope, Giuseppe; Alexe, Mircea; Sicora, Cosmin Ionel; Podar, Mircea; Banciu, Horia Leonard

    2015-12-01

    Hypersaline meromictic lakes are extreme environments in which water stratification is associated with powerful physicochemical gradients and high salt concentrations. Furthermore, their physical stability coupled with vertical water column partitioning makes them important research model systems in microbial niche differentiation and biogeochemical cycling. Here, we compare the prokaryotic assemblages from Ursu and Fara Fund hypersaline meromictic lakes (Transylvanian Basin, Romania) in relation to their limnological factors and infer their role in elemental cycling by matching taxa to known taxon-specific biogeochemical functions. To assess the composition and structure of prokaryotic communities and the environmental factors that structure them, deep-coverage small subunit (SSU) ribosomal RNA (rDNA) amplicon sequencing, community domain-specific quantitative PCR and physicochemical analyses were performed on samples collected along depth profiles. The analyses showed that the lakes harbored multiple and diverse prokaryotic communities whose distribution mirrored the water stratification patterns. Ursu Lake was found to be dominated by Bacteria and to have a greater prokaryotic diversity than Fara Fund Lake that harbored an increased cell density and was populated mostly by Archaea within oxic strata. In spite of their contrasting diversity, the microbial populations indigenous to each lake pointed to similar physiological functions within carbon degradation and sulfate reduction. Furthermore, the taxonomy results coupled with methane detection and its stable C isotope composition indicated the presence of a yet-undescribed methanogenic group in the lakes' hypersaline monimolimnion. In addition, ultrasmall uncultivated archaeal lineages were detected in the chemocline of Fara Fund Lake, where the recently proposed Nanohaloarchaeota phylum was found to thrive.

  14. Exploration of Microbial Diversity and Community Structure of Lonar Lake: The Only Hypersaline Meteorite Crater Lake within Basalt Rock

    PubMed Central

    Paul, Dhiraj; Kumbhare, Shreyas V.; Mhatre, Snehit S.; Chowdhury, Somak P.; Shetty, Sudarshan A.; Marathe, Nachiket P.; Bhute, Shrikant; Shouche, Yogesh S.

    2016-01-01

    Lonar Lake is a hypersaline and hyperalkaline soda lake and the only meteorite impact crater in the world situated in basalt rocks. Although culture-dependent studies have been reported, a comprehensive understanding of microbial community composition and structure in Lonar Lake remains elusive. In the present study, microbial community structure associated with Lonar Lake sediment and water samples was investigated using high-throughput sequencing. Microbial diversity analysis revealed the existence of diverse, yet largely consistent communities. Proteobacteria (30%), Actinobacteria (24%), Firmicutes (11%), and Cyanobacteria (5%) predominated in the sequencing survey, whereas Bacteroidetes (1.12%), BD1-5 (0.5%), Nitrospirae (0.41%), and Verrucomicrobia (0.28%) were detected in relatively minor abundances in the Lonar Lake ecosystem. Within the Proteobacteria phylum, the Gammaproteobacteria represented the most abundantly detected class (21–47%) within sediment samples, but only a minor population in the water samples. Proteobacteria and Firmicutes were found at significantly higher abundance (p ≥ 0.05) in sediment samples, whereas members of Actinobacteria, Candidate division TM7 and Cyanobacteria (p ≥ 0.05) were significantly abundant in water samples. Compared to the microbial communities of other hypersaline soda lakes, those of Lonar Lake formed a distinct cluster, suggesting a different microbial community composition and structure. Here we report for the first time, the difference in composition of indigenous microbial communities between the sediment and water samples of Lonar Lake. An improved census of microbial community structure in this Lake ecosystem provides a foundation for exploring microbial biogeochemical cycling and microbial function in hypersaline lake environments. PMID:26834712

  15. Exploration of Microbial Diversity and Community Structure of Lonar Lake: The Only Hypersaline Meteorite Crater Lake within Basalt Rock.

    PubMed

    Paul, Dhiraj; Kumbhare, Shreyas V; Mhatre, Snehit S; Chowdhury, Somak P; Shetty, Sudarshan A; Marathe, Nachiket P; Bhute, Shrikant; Shouche, Yogesh S

    2015-01-01

    Lonar Lake is a hypersaline and hyperalkaline soda lake and the only meteorite impact crater in the world situated in basalt rocks. Although culture-dependent studies have been reported, a comprehensive understanding of microbial community composition and structure in Lonar Lake remains elusive. In the present study, microbial community structure associated with Lonar Lake sediment and water samples was investigated using high-throughput sequencing. Microbial diversity analysis revealed the existence of diverse, yet largely consistent communities. Proteobacteria (30%), Actinobacteria (24%), Firmicutes (11%), and Cyanobacteria (5%) predominated in the sequencing survey, whereas Bacteroidetes (1.12%), BD1-5 (0.5%), Nitrospirae (0.41%), and Verrucomicrobia (0.28%) were detected in relatively minor abundances in the Lonar Lake ecosystem. Within the Proteobacteria phylum, the Gammaproteobacteria represented the most abundantly detected class (21-47%) within sediment samples, but only a minor population in the water samples. Proteobacteria and Firmicutes were found at significantly higher abundance (p ≥ 0.05) in sediment samples, whereas members of Actinobacteria, Candidate division TM7 and Cyanobacteria (p ≥ 0.05) were significantly abundant in water samples. Compared to the microbial communities of other hypersaline soda lakes, those of Lonar Lake formed a distinct cluster, suggesting a different microbial community composition and structure. Here we report for the first time, the difference in composition of indigenous microbial communities between the sediment and water samples of Lonar Lake. An improved census of microbial community structure in this Lake ecosystem provides a foundation for exploring microbial biogeochemical cycling and microbial function in hypersaline lake environments.

  16. Preserving the world second largest hypersaline lake under future irrigation and climate change.

    PubMed

    Shadkam, Somayeh; Ludwig, Fulco; van Vliet, Michelle T H; Pastor, Amandine; Kabat, Pavel

    2016-07-15

    Iran Urmia Lake, the world second largest hypersaline lake, has been largely desiccated over the last two decades resulting in socio-environmental consequences similar or even larger than the Aral Sea disaster. To rescue the lake a new water management plan has been proposed, a rapid 40% decline in irrigation water use replacing a former plan which intended to develop reservoirs and irrigation. However, none of these water management plans, which have large socio-economic impacts, have been assessed under future changes in climate and water availability. By adapting a method of environmental flow requirements (EFRs) for hypersaline lakes, we estimated annually 3.7·10(9)m(3) water is needed to preserve Urmia Lake. Then, the Variable Infiltration Capacity (VIC) hydrological model was forced with bias-corrected climate model outputs for both the lowest (RCP2.6) and highest (RCP8.5) greenhouse-gas concentration scenarios to estimate future water availability and impacts of water management strategies. Results showed a 10% decline in future water availability in the basin under RCP2.6 and 27% under RCP8.5. Our results showed that if future climate change is highly limited (RCP2.6) inflow can be just enough to meet the EFRs by implementing the reduction irrigation plan. However, under more rapid climate change scenario (RCP8.5) reducing irrigation water use will not be enough to save the lake and more drastic measures are needed. Our results showed that future water management plans are not robust under climate change in this region. Therefore, an integrated approach of future land-water use planning and climate change adaptation is therefore needed to improve future water security and to reduce the desiccating of this hypersaline lake.

  17. Preserving the World Second Largest Hypersaline Lake under Future Irrigation and Climate Change

    NASA Astrophysics Data System (ADS)

    Shadkam, Somayeh; Ludwig, Fulco; van Vliet, Michelle; Pastor, Amandine; Kabat, Pavel

    2016-04-01

    Urmia Lake, the world second largest hypersaline lake, has been largely desiccated over the last two decades resulting in socio-environmental consequences similar or even larger than the Aral Sea disaster. To rescue the lake a new water management plan has been proposed, a rapid 40% decline in irrigation water use replacing a former plan which intended to develop reservoirs and irrigation. However, none of these water management plans, which have large socio-economic impacts, have been assessed under future changes in climate and water availability. By adapting a method of environmental flow requirements (EFRs) for hypersaline lakes, we estimated annually 3.9•109 m3 water is needed to preserve Urmia Lake. Then, the Variable Infiltration Capacity (VIC) hydrological model was forced with bias-corrected climate model outputs for both the lowest (RCP2.6) and highest (RCP8.5) greenhouse-gas concentration scenarios to estimate future water availability and impacts of water management strategies. Results showed a 10% decline in future water availability in the basin under RCP2.6 and 27% under RCP8.5. Our results showed that if future climate change is highly limited (RCP2.6) inflow can be just enough to meet the EFRs by implementing the reduction irrigation plan. However, under more rapid climate change scenario (RCP8.5) reducing irrigation water use will not be enough to save the lake and more drastic measures are needed. Our results showed that future water management plans are not robust under climate change in this region. Therefore, an integrated approach of future land-water use planning and climate change adaptation is therefore needed to improve future water security and to reduce the desiccating of this hypersaline lake.

  18. Anaerobic halo- alkaliphilic bacterial community of athalassic, hypersaline Mono lake and Owens Lake in California

    NASA Astrophysics Data System (ADS)

    Pikuta, Elena V.; Detkova, Ekaterina N.; Bej, Asim K.; Marsic, Damien; Hoover, Richard B.

    2003-02-01

    The bacterial diversity of microbial extremophiles from the meromictic, hypersaline Mono Lake and a small evaporite pool in Owens Lake of California was studied. In spite of these regions had differing mineral background and different concentrations of NaCl in water they contain the same halo- alkaliphiles anaerobic bacterial community. Three new species of bacteria were detected in this community: primary anaerobe, dissipotrophic saccharolytic spirochete Spirochaeta americana strain AspG1T, primary anaerobe which is proteolytic Tindallia californiensis strain APOT, and secondary anaerobe, hydrogen using Desulfonatronum thiodismutans strain MLF1T, which is sulfate- reducer with chemo-litho-autotrophic metabolism. All of these bacteria are obligate alkaliphiles and dependent upon Na+ ions and CO32- ions in growth mediums. It is interesting that closest relationships for two of these species were isolates from samples of equatorial African soda Magadi lake: Spirochaeta americana AspG1T has 99.4% similarity on 16S rDNA- analyses with Spirochaeta alkalica Z- 7491T, and Tindallia californiensis APOT has 99.1% similarity with Tindallia magadiensis Z-7934T. But result of DNA-DNA- hybridization demonstrated less then 50% similarity between Spirochaeta americana AspG1T and Spirochaeta alkalica Z-7491T. Percent of homology between Tindallia californiensis APOT and Tindallia magadiensis Z-7934T is only 55%. The sulfate-reducer from the alkalic anaerobic community of Magadi lake Desulfonatronovibrio hydrogenovorans Z-7935T was phylogenetically distant from this sulfate-reducer in Mono lake, but genetically closer (99.7% similarity) to the sulfate-reducer, isolated from Central Asian alkalic lake Khadyn in Siberia Desulfonatronum lacustre Z-7951T. The study of key enzymes (hydrogenase and CO- hydrogenase) in Tindallia californiensis APOT and Desulfonatronum thiodismutans MLF1T showed the presence of high activity of both the enzymes in first and only hydrogenase in second

  19. Spatial and temporal distribution of archaeal diversity in meromictic, hypersaline Ocnei Lake (Transylvanian Basin, Romania).

    PubMed

    Baricz, Andreea; Coman, Cristian; Andrei, Adrian Stefan; Muntean, Vasile; Keresztes, Zsolt Gyula; Păuşan, Manuela; Alexe, Mircea; Banciu, Horia Leonard

    2014-03-01

    Saline, meromictic lakes with significant depth are usually formed as a result of salt mining activity. Ocnei Lake is one of the largest Transylvanian (Central Romania) neutral, hypersaline lake of man-made origin. We aimed to survey the seasonal dynamics of archaeal diversity in the water column of Ocnei Lake by employing microbiological methods as well as molecular techniques based on the sequence analysis of the 16S rRNA gene. We found that archaeal diversity in the water column increased with depth and salinity, with 8 OTUs being detected in the epilimnion compared to 21 found in the chemocline, and 32 OTUs in the monimolimnion. Down to 3.5 m depth, the archaeal community was markedly dominated by the presence of an unclassified archaeon sharing 93% sequence identity to Halogeometricum spp. At the chemocline, the shift in archaeal community composition was associated with an increase in salinity, the main factor affecting the vertical distribution of archaeal assemblages. It appears that the microoxic and hypersaline monimolimnion is populated by several major haloarchaeal taxa, with minor fluctuations in their relative abundances throughout all seasons. The culturable diversity was reasonably correlated to the dominant OTUs obtained by molecular methods. Our results indicate that Ocnei Lake represents a relatively stable extreme habitat, accommodating a diverse and putatively novel archaeal community, as 30% of OTUs could not be classified at the genus level.

  20. Microbial community structure and diversity within hypersaline Keke Salt Lake environments.

    PubMed

    Han, Rui; Zhang, Xin; Liu, Jing; Long, Qifu; Chen, Laisheng; Liu, Deli; Zhu, Derui

    2017-08-29

    Keke Salt Lake is located in the Qaidamu Basin of China, and is a unique magnesium sulfate-subtype hypersaline lake that exhibits a halite domain ecosystem, yet its microbial diversity has remained unstudied. Here, the microbial community structure and diversity was investigated via high-throughput sequencing of the V3-V5 regions of 16S rRNA genes. A high diversity of OTUs were detected for Bacteria and Archaea (734 and 747, respectively) which comprised 21 phyla, 43 classes, and 201 genera of Bacteria and 4 phyla, 4 classes, and 39 genera of Archaea. Salt-saturated samples were dominated by the bacterial genera Bacillus (51.52%-58.35% relative abundance), Lactococcus (9.52%-10.51%) and Oceanobacillus (8.82%-9.88%) within the Firmicutes phylum (74.81-80.99%) contrasting with other hypersaline lakes. The dominant Archaea belonged to the Halobacteriaceae family, and in particular, the abundant genera (>10% of communities) Halonotius, Halorubellus, Halapricum, Halorubrum and Natronomonas. Additionally, we report the presence of Nanohaloarchaeota and Woesearchaeota in Qinghai-Tibet Plateau lakes, which has not been previously documented. Total salinity (especially Mg2+, Cl-, Na+ and K+) most correlated to taxonomic distribution across samples. These results expand our understanding of microbial resource utilization within hypersaline lakes and the potential adaptations of dominant microorganisms that allow them to inhabit such environments.

  1. Clustering chlorine reactivity of haloacetic acid precursors in inland lakes.

    PubMed

    Zeng, Teng; Arnold, William A

    2014-01-01

    Dissolved organic matter (DOM) represents the major pool of organic precursors for harmful disinfection byproducts, such as haloacetic acids (HAAs), formed during drinking water chlorination, but much of it remains molecularly uncharacterized. Knowledge of model precursors is thus a prerequisite for understanding the more complex whole water DOM. The utility of HAA formation potential data from model DOM precursors, however, is limited due to the lack of comparability to water samples. In this study, the formation kinetics of dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA), the two predominant HAA species, were delineated upon chlorination of seventeen model DOM precursors and sixty-eight inland lake water samples collected from the Upper Midwest region of the United States. Of particular interest was the finding that the DCAA and TCAA formation rate constants could be grouped into four statistically distinct clusters reflecting the core structural features of model DOM precursors (i.e., non-β-diketone aliphatics, β-diketone aliphatics, non-β-diketone phenolics, and β-diketone phenolics). A comparative approach built upon hierarchical cluster analysis was developed to gain further insight into the chlorine reactivity patterns of HAA precursors in inland lake waters as defined by the relative proximity to four model precursor clusters. This work highlights the potential for implementing an integrated kinetic-clustering approach to constrain the chlorine reactivity of DOM in source waters.

  2. Morphological characterization of viruses in the stratified water column of alkaline, hypersaline Mono Lake.

    PubMed

    Brum, Jennifer R; Steward, Grieg F

    2010-10-01

    Concentrations of viruses and prokaryotes in the alkaline, moderately hypersaline, seasonally stratified Mono Lake are among the highest reported for a natural aquatic environment. We used electron microscopy to test whether viral morphological characteristics differed among the epilimnion, metalimnion, and the anoxic hypolimnion of the lake and to determine how the properties of viruses in Mono Lake compare to other aquatic environments. Viral capsid size distributions were more similar in the metalimnion and hypolimnion of Mono Lake, while viral tail lengths were more similar in the epilimnion and metalimnion. The percentage of tailed viruses decreased with depth and the relative percentages of tailed phage families changed with depth. The presence of large (>125 nm capsid), untailed viruses in the metalimnion and hypolimnion suggests that eukaryotic viruses are produced in these suboxic and anoxic, hypersaline environments. Capsid diameters of viruses were larger on average in Mono Lake compared to other aquatic environments, and no lemon-shaped or filamentous viruses were found, in contrast to other high-salinity or high-altitude lakes and seas. Our data suggest that the physically and chemically distinct layers of Mono Lake harbor different viral assemblages, and that these assemblages are distinct from other aquatic environments that have been studied. Furthermore, we found that filtration of a sample through a 0.22-µm pore-size filter significantly altered the distribution of viral capsid diameters and tail lengths, resulting in a relative depletion of viruses having larger capsids and longer tails. This observation highlights the potential for bias in molecular surveys of viral diversity, which typically rely on filtration through 0.2- or 0.22-µm pore-size membrane filters to remove bacteria during sample preparation.

  3. The comparative osmoregulatory ability of two water beetle genera whose species span the fresh-hypersaline gradient in inland waters (Coleoptera: Dytiscidae, Hydrophilidae).

    PubMed

    Pallarés, Susana; Arribas, Paula; Bilton, David T; Millán, Andrés; Velasco, Josefa

    2015-01-01

    A better knowledge of the physiological basis of salinity tolerance is essential to understanding the ecology and evolutionary history of organisms that have colonized inland saline waters. Coleoptera are amongst the most diverse macroinvertebrates in inland waters, including saline habitats; however, the osmoregulatory strategies they employ to deal with osmotic stress remain unexplored. Survival and haemolymph osmotic concentration at different salinities were examined in adults of eight aquatic beetle species which inhabit different parts of the fresh-hypersaline gradient. Studied species belong to two unrelated genera which have invaded saline waters independently from freshwater ancestors; Nebrioporus (Dytiscidae) and Enochrus (Hydrophilidae). Their osmoregulatory strategy (osmoconformity or osmoregulation) was identified and osmotic capacity (the osmotic gradient between the animal's haemolymph and the external medium) was compared between species pairs co-habiting similar salinities in nature. We show that osmoregulatory capacity, rather than osmoconformity, has evolved independently in these different lineages. All species hyperegulated their haemolymph osmotic concentration in diluted waters; those living in fresh or low-salinity waters were unable to hyporegulate and survive in hyperosmotic media (> 340 mosmol kg(-1)). In contrast, the species which inhabit the hypo-hypersaline habitats were effective hyporegulators, maintaining their haemolymph osmolality within narrow limits (ca. 300 mosmol kg(-1)) across a wide range of external concentrations. The hypersaline species N. ceresyi and E. jesusarribasi tolerated conductivities up to 140 and 180 mS cm(-1), respectively, and maintained osmotic gradients over 3500 mosmol kg(-1), comparable to those of the most effective insect osmoregulators known to date. Syntopic species of both genera showed similar osmotic capacities and in general, osmotic responses correlated well with upper salinity levels occupied by

  4. The Comparative Osmoregulatory Ability of Two Water Beetle Genera Whose Species Span the Fresh-Hypersaline Gradient in Inland Waters (Coleoptera: Dytiscidae, Hydrophilidae)

    PubMed Central

    Pallarés, Susana; Arribas, Paula; Bilton, David T.; Millán, Andrés; Velasco, Josefa

    2015-01-01

    A better knowledge of the physiological basis of salinity tolerance is essential to understanding the ecology and evolutionary history of organisms that have colonized inland saline waters. Coleoptera are amongst the most diverse macroinvertebrates in inland waters, including saline habitats; however, the osmoregulatory strategies they employ to deal with osmotic stress remain unexplored. Survival and haemolymph osmotic concentration at different salinities were examined in adults of eight aquatic beetle species which inhabit different parts of the fresh—hypersaline gradient. Studied species belong to two unrelated genera which have invaded saline waters independently from freshwater ancestors; Nebrioporus (Dytiscidae) and Enochrus (Hydrophilidae). Their osmoregulatory strategy (osmoconformity or osmoregulation) was identified and osmotic capacity (the osmotic gradient between the animal’s haemolymph and the external medium) was compared between species pairs co-habiting similar salinities in nature. We show that osmoregulatory capacity, rather than osmoconformity, has evolved independently in these different lineages. All species hyperegulated their haemolymph osmotic concentration in diluted waters; those living in fresh or low-salinity waters were unable to hyporegulate and survive in hyperosmotic media (> 340 mosmol kg-1). In contrast, the species which inhabit the hypo-hypersaline habitats were effective hyporegulators, maintaining their haemolymph osmolality within narrow limits (ca. 300 mosmol kg-1) across a wide range of external concentrations. The hypersaline species N. ceresyi and E. jesusarribasi tolerated conductivities up to 140 and 180 mS cm-1, respectively, and maintained osmotic gradients over 3500 mosmol kg-1, comparable to those of the most effective insect osmoregulators known to date. Syntopic species of both genera showed similar osmotic capacities and in general, osmotic responses correlated well with upper salinity levels occupied by

  5. Alkaline Hypersaline Lakes as Analogs for Ancient Microbial Habitats on Mars

    NASA Technical Reports Server (NTRS)

    McDonald, G. D.; Tsapin, A. I.; Storrie-Lombardi, M. C.; Nealson, K. H.; Brinton, K. L. F.; Sun, H.; Venkateswaren, K.; Tsapin, I.; Melack, J.; Jellison, R.

    1999-01-01

    As the climate of ancient Mars became colder and drier with time, open bodies of water would have entered a regime in which evaporation exceeded input from precipitation or runoff. This would have resulted in increases in salinity and perhaps pH. The last open water on Mars was most likely found in alkaline hypersaline lakes, and these lakes would have been the last surface aquatic habitats for life on Mars. It follows, then, that the biomarkers most likely to be found in ancient sedimentary basins on Mars are those left by organisms adapted to high salt and high pH environments. We have begun to investigate the nature of biological diversity and adaptation to these environments, and the potential for biomarker preservation in them, using Mono Lake as a terrestrial analog environment. Additional information is contained in the original extended abstract.

  6. Alkaline Hypersaline Lakes as Analogs for Ancient Microbial Habitats on Mars

    NASA Technical Reports Server (NTRS)

    McDonald, G. D.; Tsapin, A. I.; Storrie-Lombardi, M. C.; Nealson, K. H.; Brinton, K. L. F.; Sun, H.; Venkateswaren, K.; Tsapin, I.; Melack, J.; Jellison, R.

    1999-01-01

    As the climate of ancient Mars became colder and drier with time, open bodies of water would have entered a regime in which evaporation exceeded input from precipitation or runoff. This would have resulted in increases in salinity and perhaps pH. The last open water on Mars was most likely found in alkaline hypersaline lakes, and these lakes would have been the last surface aquatic habitats for life on Mars. It follows, then, that the biomarkers most likely to be found in ancient sedimentary basins on Mars are those left by organisms adapted to high salt and high pH environments. We have begun to investigate the nature of biological diversity and adaptation to these environments, and the potential for biomarker preservation in them, using Mono Lake as a terrestrial analog environment. Additional information is contained in the original extended abstract.

  7. Ecology of methanogenesis in two hypersaline biocoenoses: Great Salt Lake and a San Francisco Bay saltern

    SciTech Connect

    Paterek, J.R.

    1983-01-01

    Enrichment cultures were prepared from sediment and brine samples from two hypersaline ecosystems, Great Salt Lake in Utah and a solar saltern located in San Francisco Bay. Methane production was greater when enriched with the biopolymer chitin than with cellulose or peptone. Organisms indigenous to hypersaline ecosystems, brine shrimp (Artemia sp.), halobacteria (Halobacterium sp. and Halococcus sp.) and halophilic algae (Dunaliella sp. and others) were cultivated and added to anaerobic and aerobic microcosms prepared with brine and sediment from the ecosystems studied. Methane production and the concentration of the methanogenic precursor, trimethylamine were greatest with brine shrimp as a supplement. Choline produced the highest concentrations of methane in all samples examined. A number of marine-related ecosystems were also examined for their ability to support methanogenesis at various salinities. Methanogenesis occurred at sea water salinity in the majority of samples, and methane production was observed from three sites at salinity found in Great Salt Lake brine. A halophilic methanogenic bacterium species was isolated from both Great Salt Lake and the San Francisco Bay solar saltern sediments. Cells are irregular, nonmotile cocci, approximately 1.0uM in diameter and stain gram negative.

  8. Nitrate attenuation potential of hypersaline lake sediments in central Spain: flow-through and batch experiments.

    PubMed

    Carrey, R; Rodríguez-Escales, P; Otero, N; Ayora, C; Soler, A; Gómez-Alday, J J

    2014-08-01

    Complex lacustrine systems, such as hypersaline lakes located in endorheic basins, are exposed to nitrate (NO3(-)) pollution. An excellent example of these lakes is the hypersaline lake located in the Pétrola basin (central Spain), where the lake acts as a sink for NO3(-) from agricultural activities and from sewage from the surrounding area. To better understand the role of the organic carbon (Corg) deposited in the bottom sediment in promoting denitrification, a four-stage flow-through experiment (FTR) and batch experiments using lake bottom sediment were performed. The chemical, multi-isotopic and kinetic characterization of the outflow showed that the intrinsic NO3(-) attenuation potential of the lake bottom sediment was able to remove 95% of the NO3(-) input over 296days under different flow conditions. The NO3(-) attenuation was mainly linked with denitrification but some dissimilatory nitrate reduction to ammonium was observed at early days favored by the high C/N ratio and salinity. Sulfate reduction could be neither confirmed nor discarded during the experiments because the sediment leaching masked the chemical and isotopic signatures of this reaction. The average nitrogen reduction rate (NRR) obtained was 1.25mmold(-1)kg(-1) and was independent of the flow rate employed. The amount of reactive Corg from the bottom sediment consumed during denitrification was 28.8mmol, representing approximately 10% of the total Corg of the sediment (1.2%). Denitrification was produced coupled with an increase in the isotopic composition of both δ(15)N and δ(18)O. The isotopic fractionations (ε of (15)N-NO3(-) and (18)O-NO3(-)) produced during denitrification were calculated using batch and vertical profile samples. The results were -14.7‰ for εN and -14.5‰ for εO. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. 46 CFR 11.431 - Tonnage requirements for Great Lakes and inland endorsements for vessels of over 1600 gross tons.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Tonnage requirements for Great Lakes and inland... Requirements for Deck Officers § 11.431 Tonnage requirements for Great Lakes and inland endorsements for vessels of over 1600 gross tons. (a) All required experience for Great Lakes and inland unlimited...

  10. 46 CFR 11.437 - Requirements for mate of Great Lakes and inland self-propelled vessels of unlimited tonnage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Requirements for mate of Great Lakes and inland self... Requirements for National Deck Officer Endorsements § 11.437 Requirements for mate of Great Lakes and inland... for an endorsement as mate of Great Lakes and inland self-propelled vessels of unlimited tonnage is...

  11. 46 CFR 11.431 - Tonnage requirements for Great Lakes and inland endorsements for vessels of over 1600 gross tons.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Tonnage requirements for Great Lakes and inland... Requirements for Deck Officers § 11.431 Tonnage requirements for Great Lakes and inland endorsements for vessels of over 1600 gross tons. (a) All required experience for Great Lakes and inland unlimited...

  12. 46 CFR 11.431 - Tonnage requirements for Great Lakes and inland endorsements for vessels of over 1600 gross tons.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Tonnage requirements for Great Lakes and inland... Requirements for Deck Officers § 11.431 Tonnage requirements for Great Lakes and inland endorsements for vessels of over 1600 gross tons. (a) All required experience for Great Lakes and inland unlimited...

  13. 46 CFR 11.433 - Requirements for master of Great Lakes and inland self-propelled vessels of unlimited tonnage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Requirements for master of Great Lakes and inland self... Requirements for National Deck Officer Endorsements § 11.433 Requirements for master of Great Lakes and inland... for an endorsement as master of Great Lakes and inland self-propelled vessels of unlimited tonnage is...

  14. Culturable diversity of aerobic halophilic archaea (Fam. Halobacteriaceae) from hypersaline, meromictic Transylvanian lakes.

    PubMed

    Baricz, Andreea; Cristea, Adorján; Muntean, Vasile; Teodosiu, Gabriela; Andrei, Adrian-Ştefan; Molnár, Imola; Alexe, Mircea; Rakosy-Tican, Elena; Banciu, Horia Leonard

    2015-03-01

    Perennially stratified salt lakes situated in the Transylvanian Basin (Central Romania) were surveyed for the diversity of culturable halophilic archaea (Fam. Halobacteriaceae). The physical and chemical characteristics of the waters indicated that all the investigated lakes were meromictic and neutral hypersaline. Samples collected from upper, intermediate, and deeper water layers and sediments were used for the isolation of halophilic strains followed by 16S rRNA gene-based identification and phenotypic characterization. The phylogenetic analysis of the 16S rRNA gene sequences revealed that all 191 isolates reported in this study and 43 strains previously isolated were affiliated with the family Halobacteriaceae and classified to 18 genera. Haloferax was the most frequently isolated genus (~47 %), followed by Halobacterium spp. (~12 %), and Halorubrum spp. (~11 %). Highest culturable diversity was detected in Brâncoveanu Lake, the oldest and saltiest of all studied lakes, while the opposite was observed in the most stable and least human-impacted Fără Fund Lake. One strain from Ursu Lake might possibly constitute a novel Halorubrum species as shown by phylogenetic analysis. Several haloarchaeal taxa recently described in Asian (i.e., Iran, China) saline systems were also identified as inhabiting the Transylvanian salt lakes thus expanding our knowledege on the geographic distribution of Halobacteriaceae.

  15. Electricity generation by anaerobic bacteria and anoxic sediments from hypersaline soda lakes

    USGS Publications Warehouse

    Miller, L.G.; Oremland, R.S.

    2008-01-01

    Anaerobic bacteria and anoxic sediments from soda lakes produced electricity in microbial fuel cells (MFCs). No electricity was generated in the absence of bacterial metabolism. Arsenate respiring bacteria isolated from moderately hypersaline Mono Lake (Bacillus selenitireducens), and salt-saturated Searles Lake, CA (strain SLAS-1) oxidized lactate using arsenate as the electron acceptor. However, these cultures grew equally well without added arsenate using the MFC anode as their electron acceptor, and in the process oxidized lactate more efficiently. The decrease in electricity generation by consumption of added alternative electron acceptors (i.e. arsenate) which competed with the anode for available electrons proved to be a useful indicator of microbial activity and hence life in the fuel cells. Shaken sediment slurries from these two lakes also generated electricity, with or without added lactate. Hydrogen added to sediment slurries was consumed but did not stimulate electricity production. Finally, electricity was generated in statically incubated "intact" sediment cores from these lakes. More power was produced in sediment from Mono Lake than from Searles Lake, however microbial fuel cells could detect low levels of metabolism operating under moderate and extreme conditions of salt stress. ?? 2008 US Government.

  16. Electricity generation by anaerobic bacteria and anoxic sediments from hypersaline soda lakes.

    PubMed

    Miller, Laurence G; Oremland, Ronald S

    2008-11-01

    Anaerobic bacteria and anoxic sediments from soda lakes produced electricity in microbial fuel cells (MFCs). No electricity was generated in the absence of bacterial metabolism. Arsenate respiring bacteria isolated from moderately hypersaline Mono Lake (Bacillus selenitireducens), and salt-saturated Searles Lake, CA (strain SLAS-1) oxidized lactate using arsenate as the electron acceptor. However, these cultures grew equally well without added arsenate using the MFC anode as their electron acceptor, and in the process oxidized lactate more efficiently. The decrease in electricity generation by consumption of added alternative electron acceptors (i.e. arsenate) which competed with the anode for available electrons proved to be a useful indicator of microbial activity and hence life in the fuel cells. Shaken sediment slurries from these two lakes also generated electricity, with or without added lactate. Hydrogen added to sediment slurries was consumed but did not stimulate electricity production. Finally, electricity was generated in statically incubated "intact" sediment cores from these lakes. More power was produced in sediment from Mono Lake than from Searles Lake, however microbial fuel cells could detect low levels of metabolism operating under moderate and extreme conditions of salt stress.

  17. Ecophysiological Distinctions of Haloarchaea from a Hypersaline Antarctic Lake as Determined by Metaproteomics

    PubMed Central

    Tschitschko, Bernhard; Williams, Timothy J.; Allen, Michelle A.; Zhong, Ling; Raftery, Mark J.

    2016-01-01

    ABSTRACT Deep Lake in the Vestfold Hills is hypersaline and the coldest system in Antarctica known to support microbial growth (temperatures as low as −20°C). It represents a strong experimental model because the lake supports a low-complexity community of haloarchaea, with the three most abundant species totaling ∼72%. Moreover, the dominant haloarchaea are cultivatable, and their genomes are sequenced. Here we use metaproteomics linked to metagenome data and the genome sequences of the isolates to characterize the main pathways, trophic strategies, and interactions associated with resource utilization. The dominance of the most abundant member, Halohasta litchfieldiae, appears to be predicated on competitive utilization of substrates (e.g., starch, glycerol, and dihydroxyacetone) produced by Dunaliella, the lake's primary producer, while also possessing diverse mechanisms for acquiring nitrogen and phosphorus. The second most abundant member, strain DL31, is proficient in degrading complex proteinaceous matter. Hht. litchfieldiae and DL31 are inferred to release labile substrates that are utilized by Halorubrum lacusprofundi, the third most abundant haloarchaeon in Deep Lake. The study also linked genome variation to specific protein variants or distinct genetic capacities, thereby identifying strain-level variation indicative of specialization. Overall, metaproteomics revealed that rather than functional differences occurring at different lake depths or through size partitioning, the main lake genera possess major trophic distinctions, and phylotypes (e.g., strains of Hht. litchfieldiae) exhibit a more subtle level of specialization. This study highlights the extent to which the lake supports a relatively uniform distribution of taxa that collectively possess the genetic capacity to effectively exploit available nutrients throughout the lake. IMPORTANCE Life on Earth has evolved to colonize a broad range of temperatures, but most of the biosphere (∼85

  18. Metagenomic insights into strategies of carbon conservation and unusual sulfur biogeochemistry in a hypersaline Antarctic lake

    PubMed Central

    Yau, Sheree; Lauro, Federico M; Williams, Timothy J; DeMaere, Matthew Z; Brown, Mark V; Rich, John; Gibson, John AE; Cavicchioli, Ricardo

    2013-01-01

    Organic Lake is a shallow, marine-derived hypersaline lake in the Vestfold Hills, Antarctica that has the highest reported concentration of dimethylsulfide (DMS) in a natural body of water. To determine the composition and functional potential of the microbial community and learn about the unusual sulfur chemistry in Organic Lake, shotgun metagenomics was performed on size-fractionated samples collected along a depth profile. Eucaryal phytoflagellates were the main photosynthetic organisms. Bacteria were dominated by the globally distributed heterotrophic taxa Marinobacter, Roseovarius and Psychroflexus. The dominance of heterotrophic degradation, coupled with low fixation potential, indicates possible net carbon loss. However, abundant marker genes for aerobic anoxygenic phototrophy, sulfur oxidation, rhodopsins and CO oxidation were also linked to the dominant heterotrophic bacteria, and indicate the use of photo- and lithoheterotrophy as mechanisms for conserving organic carbon. Similarly, a high genetic potential for the recycling of nitrogen compounds likely functions to retain fixed nitrogen in the lake. Dimethylsulfoniopropionate (DMSP) lyase genes were abundant, indicating that DMSP is a significant carbon and energy source. Unlike marine environments, DMSP demethylases were less abundant, indicating that DMSP cleavage is the likely source of high DMS concentration. DMSP cleavage, carbon mixotrophy (photoheterotrophy and lithoheterotrophy) and nitrogen remineralization by dominant Organic Lake bacteria are potentially important adaptations to nutrient constraints. In particular, carbon mixotrophy relieves the extent of carbon oxidation for energy production, allowing more carbon to be used for biosynthetic processes. The study sheds light on how the microbial community has adapted to this unique Antarctic lake environment. PMID:23619305

  19. Draft Genome Sequence of "Candidatus Halobonum tyrrellensis" Strain G22, Isolated from the Hypersaline Waters of Lake Tyrrell, Australia.

    PubMed

    Ugalde, Juan A; Narasingarao, Priya; Kuo, Sidney; Podell, Sheila; Allen, Eric E

    2013-12-12

    We report the draft 3.675-Mbp genome sequence of "Candidatus Halobonum tyrrellensis" strain G22, a novel halophilic archaeon isolated from the surface hypersaline waters of Lake Tyrrell, Australia. The availability of the first genome from the "Candidatus Halobonum" genus provides a new genomic resource for the comparative genomic analysis of halophilic Archaea.

  20. Egg banks in hypersaline lakes of the South-East Europe

    PubMed Central

    Moscatello, Salvatore; Belmonte, Genuario

    2009-01-01

    The cyst banks of 6 coastal hypersaline lakes of South-East Europe have been investigated. The study concerned the bottom sediments of Khersonesskoe and Koyashskoe lakes in the Crimea (Ukraine), Nartë saltworks (Albania), Vecchia Salina at Torre Colimena (Apulia, Italy), Pantano Grande and Pantano Roveto at Vendicari (Sicily, Italy). A total of 19 cyst types were recognised. The cyst banks of lakes were found to be well separated in the representation derived from a statistical multivariate data analysis. For all the lakes examined a comparison was possible between the resting community in sediments (cyst bank) and the active one in the water. The cyst banks contained more species than those recorded over a multi-year sampling effort in the water column. The study of cyst hatching, performed on 5 cyst types under lab conditions, demonstrated that cysts do not hatch under the same conditions. Furthermore, each cyst type shows a wide range of preferential hatching conditions, which allow us to confirm the ecological generalism of salt lake species. PMID:19292906

  1. FACTORS AFFECTING ENHANCED MERCURY BIOACCUMULATION IN INLAND LAKES OF ISLE ROYALE NATIONAL PARK, USA

    EPA Science Inventory

    Recent results have shown that 6 of the 43 inland lakes of Isle Royale National Park, the largest island in Lake Superior, contain northen pike with mercury concentrations exceeding health conxumption advisory levels (> 500 ng/g ww). Standard length (550 mm) pike in advisory lake...

  2. 46 CFR 90.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited... are concerned on any inland routes, including the Great Lakes. ... 46 Shipping 4 2013-10-01 2013-10-01 false Ocean or unlimited coastwise vessels on inland and Great...

  3. Virus-Host and CRISPR Dynamics in Archaea-Dominated Hypersaline Lake Tyrrell, Victoria, Australia

    DOE PAGES

    Emerson, Joanne B.; Andrade, Karen; Thomas, Brian C.; ...

    2013-01-01

    The study of natural archaeal assemblages requires community context, namely, a concurrent assessment of the dynamics of archaeal, bacterial, and viral populations. Here, we use filter size-resolved metagenomic analyses to report the dynamics of 101 archaeal and bacterial OTUs and 140 viral populations across 17 samples collected over different timescales from 2007–2010 from Australian hypersaline Lake Tyrrell (LT). All samples were dominated by Archaea (75–95%). Archaeal, bacterial, and viral populations were found to be dynamic on timescales of months to years, and different viral assemblages were present in planktonic, relative to host-associated (active and provirus) size fractions. Analyses of clusteredmore » regularly interspaced short palindromic repeat (CRISPR) regions indicate that both rare and abundant viruses were targeted, primarily by lower abundance hosts. Although very few spacers had hits to the NCBI nr database or to the 140 LT viral populations, 21% had hits to unassembled LT viral concentrate reads. This suggests local adaptation to LT-specific viruses and/or undersampling of haloviral assemblages in public databases, along with successful CRISPR-mediated maintenance of viral populations at abundances low enough to preclude genomic assembly. This is the first metagenomic report evaluating widespread archaeal dynamics at the population level on short timescales in a hypersaline system.« less

  4. Virus-host and CRISPR dynamics in Archaea-dominated hypersaline Lake Tyrrell, Victoria, Australia.

    PubMed

    Emerson, Joanne B; Andrade, Karen; Thomas, Brian C; Norman, Anders; Allen, Eric E; Heidelberg, Karla B; Banfield, Jillian F

    2013-01-01

    The study of natural archaeal assemblages requires community context, namely, a concurrent assessment of the dynamics of archaeal, bacterial, and viral populations. Here, we use filter size-resolved metagenomic analyses to report the dynamics of 101 archaeal and bacterial OTUs and 140 viral populations across 17 samples collected over different timescales from 2007-2010 from Australian hypersaline Lake Tyrrell (LT). All samples were dominated by Archaea (75-95%). Archaeal, bacterial, and viral populations were found to be dynamic on timescales of months to years, and different viral assemblages were present in planktonic, relative to host-associated (active and provirus) size fractions. Analyses of clustered regularly interspaced short palindromic repeat (CRISPR) regions indicate that both rare and abundant viruses were targeted, primarily by lower abundance hosts. Although very few spacers had hits to the NCBI nr database or to the 140 LT viral populations, 21% had hits to unassembled LT viral concentrate reads. This suggests local adaptation to LT-specific viruses and/or undersampling of haloviral assemblages in public databases, along with successful CRISPR-mediated maintenance of viral populations at abundances low enough to preclude genomic assembly. This is the first metagenomic report evaluating widespread archaeal dynamics at the population level on short timescales in a hypersaline system.

  5. Comparison of chitinolytic enzymes from an alkaline, hypersaline lake and an estuary.

    PubMed

    LeCleir, Gary R; Buchan, Alison; Maurer, John; Moran, Mary Ann; Hollibaugh, James T

    2007-01-01

    We examined the genetic and physiological characteristics of chitin degrading enzymes expressed by fosmids cloned from two strains of chitinolytic gammaproteobacteria isolated from alkaline, hypersaline Mono Lake, California; and from a metagenomic library derived from an estuarine bacterial community (Dean Creek, Sapelo Island, GA, USA). The Mono Lake chitinolytic enzymes presented unique adaptations in terms of halo- and alkalitolerance. The sequence from one of the Mono Lake isolates (strain 12A) was a conventional family 18 glycosyl hydrolase; however, the expressed protein had a novel secondary activity peak at pH 10. We obtained a novel family 20 glycosyl hydrolase sequence from Mono Lake strain AI21. The activity of the expressed protein had a pH optimum of 10, several pH units higher than any other enzyme currently assigned to this family, and the enzyme retained 80% of its activity at pH 11. The enzyme was also halotolerant, retaining activity in salt solutions of up to 225 g l(-1). Sequence analysis indicated a molecular weight of approximately 90 kDa for the protein, and that it contained two active sites. Culture supernatant contained two chitinolytic proteins, 45 and 31 kDa, suggesting possible post-expression modification of the gene product. In contrast, the sequence found in the estuarine metagenomic library and the functional characteristics of the protein expressed from it were those of a conventional family 18 glycosyl hydrolase.

  6. Estimation of a Trophic State Index for selected inland lakes in Michigan, 1999–2013

    USGS Publications Warehouse

    Fuller, Lori M.; Jodoin, Richard S.

    2016-03-11

    A 15-year estimated Trophic State Index (eTSI) for Michigan inland lakes is available, and it spans seven datasets, each representing 1 to 3 years of data from 1999 to 2013. On average, 3,000 inland lake eTSI values are represented in each of the datasets by a process that relates field-measured Secchi-disk transparency (SDT) to Landsat satellite imagery to provide eTSI values for unsampled inland lakes. The correlation between eTSI values and field-measured Trophic State Index (TSI) values from SDT was strong as shown by R2 values from 0.71 to 0.83. Mean eTSI values ranged from 42.7 to 46.8 units, which when converted to estimated SDT (eSDT) ranged from 8.9 to 12.5 feet for the datasets. Most eTSI values for Michigan inland lakes are in the mesotrophic TSI class. The Environmental Protection Agency (EPA) Level III Ecoregions were used to illustrate and compare the spatial distribution of eTSI classes for Michigan inland lakes. Lakes in the Northern Lakes and Forests, North Central Hardwood Forests, and Southern Michigan/Northern Indiana Drift Plains ecoregions are predominantly in the mesotrophic TSI class. The Huron/Erie Lake Plains and Eastern Corn Belt Plains ecoregions, had predominantly eutrophic class lakes and also the highest percent of hypereutrophic lakes than other ecoregions in the State. Data from multiple sampling programs—including data collected by volunteers with the Cooperative Lakes Monitoring Program (CLMP) through the Michigan Department of Environmental Quality (MDEQ), and the 2007 National Lakes Assessment (NLA)—were compiled to compare the distribution of lake TSI classes between each program. The seven eTSI datasets are available for viewing and download with eSDT from the Michigan Lake Water Clarity Interactive Map Viewer at http://mi.water.usgs.gov/projects/RemoteSensing/index.html.

  7. The sources and evolution of sulfur in the hypersaline Lake Lisan (paleo-Dead Sea)

    NASA Astrophysics Data System (ADS)

    Torfstein, Adi; Gavrieli, Ittai; Stein, Mordechai

    2005-07-01

    δ34S values in gypsum are used to evaluate the fate of sulfur in the hypersaline Lake Lisan, the late Pleistocene precursor of the Dead Sea (70-14 ka BP), and applied as a paleo-limnological tracer. The Ca-chloride Lake Lisan evolved through meromictic periods characterized by precipitation of authigenic aragonite and holomictic episodes characterized by enhanced gypsum precipitation. The lake deposited two major gypsum units: the "Lower Gypsum unit" (deposited at ˜56 ka) showing δ34S values of 18-20‰, and the "Upper Gypsum unit" (deposited at 17 ka) displaying significantly higher δ34S values of 26-28‰. Laminated and disseminated gypsum, residing within the aragonite, exhibit δ34S values in the range of - 26‰ to 1‰. The isotopic composition of the gypsum was dictated by freshwater sulfate input that replenished the upper layer of the lake (the mixolimnion), bacterial sulfate reduction (BSR) that occurred under the anoxic conditions of the lower brine (the monimolimnion), and mixing between these two layers. During meromictic periods, the sulfate reservoir in the lower brine was replenished by precipitation of gypsum from the upper layer, and its subsequent dissolution due to sulfate deficiency induced by BSR activity. This process describes a "sulfur pump" mechanism and its effect on δ34S in the water can be modeled by a modified Rayleigh distillation equation. Steady state δ34S values (˜40‰) were reached in the lower brine after long meromictic periods. Following overturn episodes, induced by diminishing freshwater input and lake level decline, large quantities of δ34S enriched gypsum precipitated. The negative δ34S values in laminated and disseminated gypsum provide evidence for BSR activity in the lower brine that removed isotopically depleted sulfides from the water column, causing significant isotopic enrichment of remaining sulfate. Following the lake desiccation, the sediments were exposed and the latter sulfides oxidized and re

  8. Distribution and Diversity of Archaea Corresponding to the Limnological Cycle of a Hypersaline Stratified Lake (Solar Lake, Sinai, Egypt)

    PubMed Central

    Cytryn, Eddie; Minz, Dror; Oremland, Ronald S.; Cohen, Yehuda

    2000-01-01

    The vertical and seasonal distribution and diversity of archaeal sequences was investigated in a hypersaline, stratified, monomictic lake, Solar Lake, Sinai, Egypt, during the limnological development of stratification and mixing. Archaeal sequences were studied via phylogenetic analysis of 16S rDNA sequences as well as denaturing gradient gel electrophoresis analysis. The 165 clones studied were grouped into four phylogenetically different clusters. Most of the clones isolated from both the aerobic epilimnion and the sulfide-rich hypolimnion were defined as cluster I, belonging to the Halobacteriaceae family. The three additional clusters were all isolated from the anaerobic hypolimnion. Cluster II is phylogenetically located between the genera Methanobacterium and Methanococcus. Clusters III and IV relate to two previously documented groups of uncultured euryarchaeota, remotely related to the genus Thermoplasma. No crenarchaeota were found in the water column of the Solar Lake. The archaeal community in the Solar Lake under both stratified and mixed conditions was dominated by halobacteria in salinities higher than 10%. During stratification, additional clusters, some of which may possibly relate to uncultured halophilic methanogens, were found in the sulfide- and methane-rich hypolimnion. PMID:10919780

  9. Vertical distribution of nitrogen-fixing phylotypes in a meromictic, hypersaline lake.

    PubMed

    Steward, G F; Zehr, J P; Jellison, R; Montoya, J P; Hollibaugh, J T

    2004-01-01

    We investigated the diversity of nitrogenase genes in the alkaline, moderately hypersaline Mono Lake, California to determine (1) whether nitrogen-fixing (diazotrophic) populations were similar to those in other aquatic environments and (2) if there was a pattern of distribution of phylotypes that reflected redox conditions, as well as (3) to identify populations that could be important in N dynamics in this nitrogen-limited lake. Mono Lake has been meromictic for almost a decade and has steep gradients in oxygen and reduced compounds that provide a wide range of aerobic and anaerobic habitats. We amplified a fragment of the nitrogenase gene (nifH) from planktonic DNA samples collected at three depths representing oxygenated surface waters, the oxycline, and anoxic, ammonium-rich deep waters. Forty-three percent of the 90 sequences grouped in nifH Cluster I. The majority of clones (57%) grouped in Cluster III, which contains many known anaerobic bacteria. Cluster I and Cluster III sequences were retrieved at every depth indicating little vertical zonation in sequence types related to the prominent gradients in oxygen and ammonia. One group in Cluster I was found most often at every depth and accounted for 29% of all the clones. These sequences formed a subcluster that contained other environmental clones, but no cultivated representatives. No significant nitrogen fixation was detected by the 15N2 method after 48 h of incubation of surface, oxycline, or deep waters, suggesting that pelagic diazotrophs were contributing little to nitrogen fluxes in the lake. The failure to measure any significant nitrogen fixation, despite the detection of diverse and novel nitrogenase genes throughout the water column, raises interesting questions about the ecological controls on diazotrophy in Mono Lake and the distribution of functional genes in the environment.

  10. Abundance, distribution, and diversity of viruses in alkaline, hypersaline Mono Lake, California.

    PubMed

    Jiang, S; Steward, G; Jellison, R; Chu, W; Choi, S

    2004-01-01

    Mono Lake is a large (180 km2), alkaline (pH approximately 10), moderately hypersaline (70-85 g kg(-1)) lake lying at the western edge of the Great Basin. An episode of persistent chemical stratification (meromixis) was initiated in 1995 and has resulted in depletion of oxygen and accumulation of ammonia and sulfide beneath the chemocline. Although previous studies have documented high bacterial abundances and marked seasonal changes in phytoplankton abundance and community composition, there have been no previous reports on the occurrence of viruses in this unique lake. Based on the high concentrations and diversity of microbial life in this lake, we hypothesized that planktonic viruses are also abundant and diverse. To examine the abundance and distribution of viruses and bacteria, water samples were collected from four stations along 5 to 15 vertical depths at each station. Viral abundance ranged from 1 x 10(8) to 1 x 10(9) mL(-1), among the highest observed in any natural aquatic system examined so far. Increases (p < 0.1) in viral densities were observed in the anoxic bottom water at multiple stations. However, regression analysis indicated that viral abundance could not be predicted by any single environmental parameter. Pulsed field gel electrophoresis revealed a diverse viral community in Mono Lake with genome sizes ranging from approximately 14 to >400 kb with most of the DNA in the 30 to 60 kb size range. Cluster analysis grouped the anoxic bottom-water viral community into a unique cluster differentiating it from surface and mid-water viral communities. A hybridization study using an indigenous viral isolate as a probe revealed an episodic pattern of temporal phage distribution with strong niche stratification between oxic and anoxic waters.

  11. Selectivity of solid phase extraction for dissolved organic matter in the hypersaline Da Qaidam Lake, China.

    PubMed

    Yang, Keli; Zhang, Yaoling; Dong, Yaping; Li, Wu

    2017-09-19

    Dissolved organic matter (DOM) was isolated from the hypersaline Da Qaidam Lake using solid-phase extraction (SPE) methods with five different adsorbents: ENVI-Carb (non-porous graphitized carbon), HLB, PPL, and XAD-8 (polymer based), and ENVI-18 (silica based). Structure-selective assessments of SPE-DOM isolated using the different adsorbents were conducted using a combination of complementary analysis techniques, including dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) analysis, as well as elemental analysis, Fourier transformed infrared spectroscopy (FTIR), (1)H nuclear magnetic resonance ((1)H NMR) and pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS). The results indicated that the modified polymer based adsorbents (PPL and HLB) exhibited higher DOC recoveries than the others. The PPL and ENVI-Carb cartridges can recover representative nitrogen-containing organic components from the hypersaline lake. The SPE-DOM isolates obtained using ENVI-18 and XAD-8 adsorbents contained higher proportions of purely aliphatic, alkene, and aromatic compounds; the ENVI-Carb and PPL adsorbents showed higher affinity for polar functionalized aliphatic and nitrogen-containing compounds; HLB isolate was enriched with oxygen-rich organic compounds and sulphur-bearing components. The structural and compositional features of SPE-DOM from the hypersaline Da Qaidam Lake indicated the predominately autochthonous sources of organic matter in the lake.

  12. Utilization of ERTS-1 data to monitor and classify eutrophication of inland lakes

    NASA Technical Reports Server (NTRS)

    Chase, P. E.; Reed, L.; Smith, V. E.

    1973-01-01

    A technique is being developed for use of ERTS in estimating and monitoring trophic levels of inland lakes. Preliminary findings are that Michigan lakes and ponds of one acre or more are resolvable in bands 5, 6 and 7 of NASA MSS imagery under fair conditions (haze and 70% cloud cover). In processed imagery (CCT) smaller features, including water color patterns, are evident within some lakes of 40 acres or more. Image distortion of lake size, shape, orientation, etc. is minimal; discrimination of lakes and ponds from various wetlands is good. Subsequent ERTS and aircraft imagery will be correlated with detailed ground truth of water color and quality in eutrophic test lakes.

  13. Organic osmolytes in aerobic bacteria from mono lake, an alkaline, moderately hypersaline environment.

    PubMed

    Ciulla, R A; Diaz, M R; Taylor, B F; Roberts, M F

    1997-01-01

    The identity and concentrations of intracellular organic solutes were determined by nuclear magnetic resonance spectroscopy for two strains of aerobic, gram-negative bacteria isolated from Mono Lake, Calif., an alkaline, moderately hypersaline lake. Ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) was the major endogenous solute in both organisms. Concentrations of ectoine varied with external NaCl levels in strain ML-D but not in strain ML-G, where the level was high but invariant from 1.5 to 3.0 M NaCl. Hydroxyectoine also occurred in strain ML-D, especially at elevated NaCl concentrations (2.5 and 3.0 M), but at levels lower than those of ectoine. Exogenous organic solutes that might occur in Mono Lake were examined for their effects on the de novo synthesis of ectoine. Dimethylsulfoniopropionate (DMSP) (0.1 or 1 mM) did not significantly lower ectoine levels in either isolate, and only strain ML-G showed any capacity for DMSP accumulation. With nitrogen limitation, however, DMSP (0.1 mM) substituted for ectoine in strain ML-G and became the main organic solute. Glycine betaine (GB) was more effective than DMSP in affecting ectoine levels, principally in strain ML-D. Strain ML-D accumulated GB to 50 or 67% of its organic solute pool at 2.5 M NaCl, at an external level of 0.1 or 1 mM GB, respectively. Strain ML-D also accumulated arsenobetaine. The methylated zwitterionic compounds, probably metabolic products of phytoplankton (DMSP and GB) or brine shrimps (arsenobetaine) in Mono Lake, may function as osmolytes for indigenous bacteria when present at high concentrations or under conditions of nitrogen limitation or salt stress.

  14. Carbonate microbialites and hardgrounds from Manito Lake, an alkaline, hypersaline lake in the northern Great Plains of Canada

    NASA Astrophysics Data System (ADS)

    Last, Fawn M.; Last, William M.; Halden, Norman M.

    2010-03-01

    Manito Lake is a large, perennial, Na-SO 4 dominated saline to hypersaline lake located in the northern Great Plains of western Canada. Significant water level decrease over the past several decades has led to reduction in volume and surface area, as well as an increase in salinity. The salinity has increased from 10 ppt to about 50 ppt TDS. This decrease in water level has exposed large areas of nearshore microbialites. These organogenic structures range in size from several cm to over a meter and often form large bioherms several meters high. They have various external morphologies, vary in mineralogical composition, and show a variety of internal fabrics from finely laminated to massive. In addition to microbiolities and bioherms, the littoral zone of Manito Lake contains a variety of carbonate hardgrounds, pavements, and cemented clastic sediments. Dolomite and aragonite are the most common minerals found in these shoreline structures, however, calcite after ikaite, monohydrocalcite, magnesian calcite, and hydromagnesite are also present. The dolomite is nonstoichiometric and calcium-rich; the magnesian calcite has about 17 mol% MgCO 3. AMS radiocarbon dating of paired organic matter and endogenic carbonate material confirms little or no reservoir affect. Although there is abundant evidence for modern carbonate mineral precipitation and microbialite formation, most of the larger microbialites formed between about 2300 and 1000 cal BP, whereas the hardgrounds, cements, and laminated crusts formed about 1000-500 cal BP.

  15. Modeling the Impact of Climate Change on Lake Thermal Structure for Small Inland Lakes in the Mid-latitudes

    NASA Astrophysics Data System (ADS)

    Reinl, K. L.; Wagenbrenner, J. W.; Urban, N. R.

    2016-02-01

    Lakes in the mid-latitudes are subject to large seasonal variations in temperature that have been impacted by climate change. The focus of this study is to determine the impacts of climate change on the thermal structure of small inland lakes in the mid-latitudes. Small lakes comprise more than double the amount of the land surface than large lakes, and have gone largely underrepresented in lakes research regarding climate change. With this knowledge, we can better understand the effects of climate change on small inland lakes' physical processes and develop more holistic mitigation and management practices for these resources. We identified 517 inland lakes in Michigan based on data availability with surface areas between 0.03 and 81 km2, and subdivided this sample into 27 groups based on climate, lake surface area, and trophic state. The F-Lake model was tested using five Wisconsin lakes with varying surface areas and trophic states in two of the climate groups to determine its ability to predict observed lake temperatures. The average root mean squared error for the predicted surface and mean water temperature was 4.8 and 3.8 °C, respectively. We then applied the model to 3 lakes from each of the 27 groups under recently observed and future climate conditions from the regionally downscaled MPI ECHAM5 climate model (A2 emissions scenario) to assess the impacts of climate change on lake thermal structure. We hypothesize that small, eutrophic lakes located in warmer climates will be most strongly impacted, and this represents 20% of the lake resource in our sample. From these results, we will determine the susceptibility of lakes within and among the various climate, size, and trophic classes to the impacts of climate change as well as identify possible threats to aquatic organisms.

  16. Spatial and temporal trends of mercury loadings to Michigan inland lakes

    SciTech Connect

    Matthew J. Parsons; David T. Long; Sharon S. Yohn; John P. Giesy

    2007-08-15

    Several studies of chronologies of mercury (Hg) in inland lake sediments have demonstrated that Hg accumulation decreased in recent decades. However, episodic mercury accumulation events were recorded in some of these lakes, but not investigated in detail. Recent decreases had been attributed to the reduction of regional Hg consumption and secondary removal during process waste treatment. In addition to regional sources, local sources, including watershed disturbance, might significantly contribute to Hg loading. Here, mercury chronologies of Hg loadings based on dated sediment cores are presented for 26 inland Michigan lakes. Although spatial trends of anthropogenic inventories suggest a regional pattern dominated by human activities, sub-regional to local scale sources are also found to be significant. Temporal trends show episodic Hg accumulation events superimposed on a more general, long-term trend. Episodic increases common to lakes suggest a common source or processes common to lakes. Episodic increases unique to a lake indicate a more local scale source. Similar Hg profiles from lakes that are geographically proximal provide evidence for sub-regional to regional scale sources. Local sources and pathways for mercury to inland lakes need to be more fully understood to effectively reduce Hg loading to the environment. 48 refs., 7 figs.

  17. Mineralogy and Microbial Diversity of the Microbialites in the Hypersaline Storr's Lake, the Bahamas

    NASA Astrophysics Data System (ADS)

    Paul, Varun G.; Wronkiewicz, David J.; Mormile, Melanie R.; Foster, Jamie S.

    2016-04-01

    Microbialites found in the low-light-intensity, hypersaline waters of Storr's Lake (SL), San Salvador Island, the Bahamas, were investigated with respect to their morphology, mineralogy, and microbial diversity. Previously described microbialite morphologies, as well as a newly identified "multi-cuspate" morphology, were observed at various depths. Electron microscopy analysis revealed the presence of angular, blocky, and needle-shaped crystals with mineralized cyanobacterial filaments and remains of exopolymeric substances. X-ray diffraction studies confirmed the presence of both Mg-calcite and aragonite in the plateau-mushroom and pinnacle mound microbialites, whereas only Mg-calcite was identified in the other microbialite morphotypes. A comprehensive molecular analysis using barcoded pyrosequencing of five different microbial mat communities identified at least 12 dominant bacterial phyla. Cyanobacteria were generally low in abundance and ranged from ˜0.01% in the deeper pinnacle mounds to ˜3.2% in the shallow calcareous knobs. Other photosynthetic members included green nonsulfur bacteria of the phylum Chloroflexi and purple sulfur bacteria of the class Gammaproteobacteria. All mat types contained significant amounts of sulfate-reducing and dehalogenating bacteria. The low light intensity reaching the deeper microbialites, the lack of dominant cyanobacteria, and the abundance of sulfate reducers and Chloroflexi collectively suggest that sulfate reduction and anoxygenic photosynthetic processes influence the carbonate biomineralization process in these systems.

  18. Sulfidogenesis in hypersaline chloride-sulfate lakes of Kulunda Steppe (Altai, Russia).

    PubMed

    Sorokin, Dimitry Y; Zacharova, Elena E; Pimenov, Nikolai V; Tourova, Tatjana P; Panteleeva, Anjela N; Muyzer, Gerard

    2012-02-01

    The activity and culturable diversity of sulfidogens were investigated in anoxic sediments of four hypersaline lakes with pH 7.6-8.2 in the Kulunda Steppe (Altai, Russia). Sulfate reduction rates were low, varying from 0.1 to 6.0 nmol HS(-) /(cm(3) h) with a maximum in the top 10 cm layer. Potential sulfidogenic rates with thiosulfate and sulfur as the e-acceptors were higher than with sulfate and were stimulated by formate, lactate, and acetate. Sulfidogenesis was optimal at salt concentrations below 2 M NaCl. Cultivation at 2 M NaCl resulted in the isolation of several strains of moderately halophilic SRB, but no growth of SRB was observed at 4 M NaCl. At lithotrophic conditions (i.e., with formate or H(2) as e-donors), several closely related alkalitolerant strains belonging to the genus Desulfonatronovibrio were isolated. Enrichments at heterotrophic conditions with lactate, propionate, acetate, or butyrate using sulfate or thiosulfate as e-acceptors yielded isolates related to Desulfosalsimonas propionicica, Desulfohalobium utahense, and Desulfocella halophila. Sulfur-reducing enrichments at 2 M NaCl with ethanol produced a member of the genus Halanaerobium, while enrichments at 4 M NaCl with acetate were dominated by archaea, demonstrating for the first time such type of catabolism in haloarchaea. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  19. Mineralogy and Microbial Diversity of the Microbialites in the Hypersaline Storr's Lake, the Bahamas.

    PubMed

    Paul, Varun G; Wronkiewicz, David J; Mormile, Melanie R; Foster, Jamie S

    2016-04-01

    Microbialites found in the low-light-intensity, hypersaline waters of Storr's Lake (SL), San Salvador Island, the Bahamas, were investigated with respect to their morphology, mineralogy, and microbial diversity. Previously described microbialite morphologies, as well as a newly identified "multi-cuspate" morphology, were observed at various depths. Electron microscopy analysis revealed the presence of angular, blocky, and needle-shaped crystals with mineralized cyanobacterial filaments and remains of exopolymeric substances. X-ray diffraction studies confirmed the presence of both Mg-calcite and aragonite in the plateau-mushroom and pinnacle mound microbialites, whereas only Mg-calcite was identified in the other microbialite morphotypes. A comprehensive molecular analysis using barcoded pyrosequencing of five different microbial mat communities identified at least 12 dominant bacterial phyla. Cyanobacteria were generally low in abundance and ranged from ∼0.01% in the deeper pinnacle mounds to ∼3.2% in the shallow calcareous knobs. Other photosynthetic members included green nonsulfur bacteria of the phylum Chloroflexi and purple sulfur bacteria of the class Gammaproteobacteria. All mat types contained significant amounts of sulfate-reducing and dehalogenating bacteria. The low light intensity reaching the deeper microbialites, the lack of dominant cyanobacteria, and the abundance of sulfate reducers and Chloroflexi collectively suggest that sulfate reduction and anoxygenic photosynthetic processes influence the carbonate biomineralization process in these systems.

  20. New approaches indicate constant viral diversity despite shifts in assemblage structure in an Australian hypersaline lake.

    PubMed

    Emerson, Joanne B; Thomas, Brian C; Andrade, Karen; Heidelberg, Karla B; Banfield, Jillian F

    2013-11-01

    It is widely stated that viruses represent the most significant source of biodiversity on Earth, yet characterizing the diversity of viral assemblages in natural systems remains difficult. Viral diversity studies are challenging because viruses lack universally present, phylogenetically informative genes. Here, we developed an approach to estimate viral diversity using a series of functional and novel conserved genes. This approach provides direct estimates of viral assemblage diversity while retaining resolution at the level of individual viral populations in a natural system. We characterized viral assemblages in eight samples from hypersaline Lake Tyrrell (LT), Victoria, Australia, using 39,636 viral contigs. We defined viral operational taxonomic units (OTUs) in two ways. First, we used genes with three different functional predictions that were abundantly represented in the data set. Second, we clustered proteins of unknown function based on sequence similarity, and we chose genes represented by three clusters with numerous members to define OTUs. In combination, diversity metrics indicated between 412 and 735 sampled populations, and the number of populations remained relatively constant across samples. We determined the relative representation of each viral OTU in each sample and found that viral assemblage structures correlate with salinity and solution chemistry. LT viral assemblages were near-replicates from the same site sampled a few days apart but differed significantly on other spatial and temporal scales. The OTU definition approach proposed here paves the way for metagenomics-based analyses of viral assemblages using ecological models previously applied to bacteria and archaea.

  1. New Approaches Indicate Constant Viral Diversity despite Shifts in Assemblage Structure in an Australian Hypersaline Lake

    PubMed Central

    Thomas, Brian C.; Andrade, Karen; Heidelberg, Karla B.; Banfield, Jillian F.

    2013-01-01

    It is widely stated that viruses represent the most significant source of biodiversity on Earth, yet characterizing the diversity of viral assemblages in natural systems remains difficult. Viral diversity studies are challenging because viruses lack universally present, phylogenetically informative genes. Here, we developed an approach to estimate viral diversity using a series of functional and novel conserved genes. This approach provides direct estimates of viral assemblage diversity while retaining resolution at the level of individual viral populations in a natural system. We characterized viral assemblages in eight samples from hypersaline Lake Tyrrell (LT), Victoria, Australia, using 39,636 viral contigs. We defined viral operational taxonomic units (OTUs) in two ways. First, we used genes with three different functional predictions that were abundantly represented in the data set. Second, we clustered proteins of unknown function based on sequence similarity, and we chose genes represented by three clusters with numerous members to define OTUs. In combination, diversity metrics indicated between 412 and 735 sampled populations, and the number of populations remained relatively constant across samples. We determined the relative representation of each viral OTU in each sample and found that viral assemblage structures correlate with salinity and solution chemistry. LT viral assemblages were near-replicates from the same site sampled a few days apart but differed significantly on other spatial and temporal scales. The OTU definition approach proposed here paves the way for metagenomics-based analyses of viral assemblages using ecological models previously applied to bacteria and archaea. PMID:23995931

  2. 46 CFR 30.01-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes Routes-TB/OC.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Great Lakes Routes—TB/OC. (a) Vessels inspected and certificated for ocean or unlimited coastwise routes... on any inland route, including the Great Lakes. ... 46 Shipping 1 2013-10-01 2013-10-01 false Ocean or unlimited coastwise vessels on inland and Great...

  3. Natronoarchaeum persicum sp. nov., a haloarchaeon isolated from a hypersaline lake.

    PubMed

    Naghoni, Ali; Emtiazi, Giti; Amoozegar, Mohammad Ali; Rasooli, Mehrnoosh; Etemadifar, Zahra; Shahzadeh Fazeli, Seyed Abolhassan; Minegishi, Hiroaki; Ventosa, Antonio

    2017-09-01

    A novel halophilic archaeon, designated strain WIIAL99T, was isolated from Lake Meyghan, a hypersaline lake in Iran. Cells of strain WIIAL99T were non-motile, catalase-positive and oxidase-negative. Strain WIIAL99T required at least 2.5 M NaCl and 0.05 M MgCl2 for growth. Optimal growth was achieved at 3.5 M NaCl and 0.1 M MgCl2. The optimum pH and temperature for growth were pH 7.0 and 37-40 °C; it was able to grow at pH 6.0-8.5 and 20-55 °C. Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 8 % (w/v). The major polar lipids of strain WIIAL99T were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, disulfated diglycosyl diether and one unidentified glycolipid. The DNA G+C content of strain WIIAL99T was 66.7 mol%. The closest relative was Natronoarchaeum rubrum JCM 17119T with 98.2 % similarity in the orthologous 16S rRNA gene sequence. Analysis of 16S rRNA and rpoB' gene sequences indicated that strain WIIAL99T is a member of the genus Natronoarchaeum in the family Halobacteriaceae and forms a distinct cluster. It was concluded that strain WIIAL99T (=IBRC-M 11062T=LMG 29814T) represents a novel species of the genus Natronoarchaeum, for which the name Natronoarchaeum persicum sp. nov. is proposed.

  4. Organic osmolytes in aerobic bacteria from Mono Lake, an alkaline, moderately hypersaline environment

    SciTech Connect

    Ciulla, R.A.; Roberts, M.F.; Diaz, M.R.; Taylor, B.F.

    1997-01-01

    The identity and concentrations of intracellular organic solutes were determined by nuclear magnetic resonance spectroscopy for two strains of aerobic, gram-negative bacteria isolated from Mono Lake, California, an alkaline, moderately hypersaline lake. Ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) was the major endogenous solute in both organisms. Concentrations of ectoine varied with external NaCl levels in strain ML-D but not in strain ML-G, where the level was high but invariant from 1.5 to 3.0 M NaCl. Hydroxyectoine also occurred in strain ML-D, especially at elevated NaCl concentrations (2.5 and 3.0 M), but at levels lower than those of ectoine. Exogenous organic solutes that might occur in Mono Lake were examined for their effects on the de novo synthesis of ectoine. Dimethylsulfoniopropionate (DMSP) (0.1 or 1 mM) did not significantly lower ectoine levels in either isolate, and only strain ML-G showed any capacity for DMSP accumulation. With nitrogen limitation, however, DMSP (0.1 mM) substituted for ectoine in strain ML-G showed any capacity for DMSP accumulation. With nitrogen limitation, however, DMSP (0.1 mM) substituted for ectoine in strain ML-G and became the main organic solute. Glycine betaine (GB) was more effective than DMSP in affecting ectoine levels, principally in strain ML-D. Strain ML-D accumulated GB to 50 or 67% of its organic solute pool at 2.5 M NaCl, at an external level of 0.1 or 1 mM GB, respectively. Strain ML-D also accumulated arsenobetaine. The methylated zwitterionic compounds, probably metabolic products of phytoplankton (DMSP and GB) or brine shrimps (arsenobetaine) in Mono Lake, may function as osmolytes for indigenous bacteria when present at high concentrations or under conditions of nitrogen limitation or salt stress. 33 refs., 5 figs., 2 tabs.

  5. Chemical, crystallographic and stable isotopic properties of alunite and jarosite from acid-Hypersaline Australian lakes

    USGS Publications Warehouse

    Alpers, C.N.; Rye, R.O.; Nordstrom, D.K.; White, L.D.; King, B.-S.

    1992-01-01

    Chemical, crystallographic and isotopic analyses were made on samples containing alunite and jarosite from the sediments of four acid, hypersaline lakes in southeastern and southwestern Australia. The alunite and jarosite are K-rich with relatively low Na contents based on chemical analysis and determination of unit cell dimensions by powder X-ray diffraction. Correcting the chemical analyses of fine-grained mineral concentrates from Lake Tyrrell, Victoria, for the presence of halite, silica and poorly crystalline aluminosilicates, the following formulas indicate best estimates for solid-solution compositions: for alunite, K0.87Na0.04(H3O)0.09(Al 0.92Fe0.08)3(SO4)2(OH) 6 and for jarosite, K0.89Na0.07(H3O)0.04(Fe 0.80Al0.20)3(SO4)2(OH) 6. The ??D-values of alunite are notably larger than those for jarosite from Lake Tyrrell and it appears that the minerals have closely approached hydrogen isotope equilibrium with the acidic regional groundwaters. The ??D results are consistent with a fractionation ???60-70??? between alunite and jarosite observed in other areas. However, interpretation of ??D results is complicated by large variability in fluid ??DH2O from evaporation, mixing and possible ion hydration effects in the brine. ??D-values of water derived from jarosite by step-wise heating tend to be smaller at 250??C, at which temperature hydronium and other non-hydroxyl water is liberated, than at 550??C, where water is derived from the hydroxyl site, but the differences are not sufficiently different to invalidate measurements of total ??D obtained by conventional, single-step heating methods. ??34S-values for alunite and jarosite from the four lakes (+19.7 to +21.2??? CDT) and for aqueous sulfate from Lake Tyrrell (+18.3 to +19.8???) are close to the values for modern evaporites (+21.5 ??0.3???) and seawater (+20??0.5???) and are probably typical of seawater-derived aerosols in arid coastal environments. ??34-S-values slightly smaller than that for seawater may

  6. Dormant stages of crustaceans as a mechanism of propagation in the extreme and unpredictable environment in the Crimean hypersaline lakes

    NASA Astrophysics Data System (ADS)

    Shadrin, Nickolai V.; Anufriieva, Elena V.; Amat, Francisco; Eremin, Oleg Yu.

    2015-11-01

    A pool of dormant stages of planktonic organisms in saline lakes is a substantial component in the plankton communities; we need to take it into account to understand plankton dynamics. Hypersaline water bodies in Crimea, the largest peninsula in the Black Sea, constitute a very characteristic and peculiar habitat type in the region. We examined the presence of crustacean resting stages in sediments of dried up sites of the Crimean hypersaline lakes. Sediment samples were taken in 9 different lakes. Experiments performed on the hatching of these resting stages showed the presence of Moina salina (Cladocera), parthenogenetic Artemia and Artemia urmiana (Anostraca), Eucypris mareotica ( inflata) (Ostracoda), and Cletocamptus retrogressus (Harpacticoida). Comparing the experimental results obtained with clean dried brine shrimp cysts and those kept in sediment samples, it was noted that clean cysts hatched much faster than those from sediments did. Some components in bottom sediments slow down and desynchronize hatching from resting eggs in different groups of crustaceans. The sediments of different lakes inhibited the nauplii output from Artemia and ostracod resting eggs to different degrees. More data are needed before we can discuss the reasons of this inhibition. The nonsynchronous output of active stages from the bottom resting ones may be an adaptation that allows crustacean species to exist in extreme and unpredictably changing environments, avoiding the risk that all may emerge at once under unsuitable conditions.

  7. 46 CFR 11.444 - Requirements for mate of Great lakes and inland self-propelled vessels of less than 1,600 GRT.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Requirements for mate of Great lakes and inland self... Requirements for National Deck Officer Endorsements § 11.444 Requirements for mate of Great lakes and inland... for an endorsement as mate of Great Lakes and inland self-propelled vessels of less than 1,600 GRT is...

  8. 46 CFR 11.448 - Requirements for mate of Great Lakes and inland self-propelled vessels of less than 500 GRT.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Requirements for mate of Great Lakes and inland self... Requirements for National Deck Officer Endorsements § 11.448 Requirements for mate of Great Lakes and inland... an endorsement as mate of Great Lakes and inland self-propelled vessels of less than 500 GRT is 2...

  9. 46 CFR 11.455 - Requirements for master of Great Lakes and inland self-propelled vessels of less than 100 GRT.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Requirements for master of Great Lakes and inland self... Requirements for National Deck Officer Endorsements § 11.455 Requirements for master of Great Lakes and inland... for an endorsement as master of Great Lakes and inland self-propelled vessels of less than 100 GRT is...

  10. 46 CFR 11.444 - Service requirements for mate of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Service requirements for mate of Great Lakes and inland... Professional Requirements for Deck Officers § 11.444 Service requirements for mate of Great Lakes and inland... applicant for an endorsement as mate of Great Lakes and inland steam or motor vessels of not more than 1600...

  11. 46 CFR 11.454 - Service requirements for mate of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Service requirements for mate of Great Lakes and inland... Professional Requirements for Deck Officers § 11.454 Service requirements for mate of Great Lakes and inland... applicant for an endorsement as mate of Great Lakes and inland steam or motor vessels of not more than 200...

  12. 46 CFR 11.452 - Requirements for master of Great Lakes and inland self-propelled vessels of less than 200 GRT.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Requirements for master of Great Lakes and inland self... Requirements for National Deck Officer Endorsements § 11.452 Requirements for master of Great Lakes and inland... for an endorsement or license as master of Great Lakes and inland self-propelled vessels of less than...

  13. 46 CFR 11.454 - Service requirements for mate of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Service requirements for mate of Great Lakes and inland... Professional Requirements for Deck Officers § 11.454 Service requirements for mate of Great Lakes and inland... applicant for an endorsement as mate of Great Lakes and inland steam or motor vessels of not more than 200...

  14. 46 CFR 11.454 - Requirements for mate of Great Lakes and inland self-propelled vessels of less than 200 GRT.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Requirements for mate of Great Lakes and inland self... Requirements for National Deck Officer Endorsements § 11.454 Requirements for mate of Great Lakes and inland... for an endorsement as mate of Great Lakes and inland self-propelled vessels of less than 200 GRT is 6...

  15. 46 CFR 11.454 - Service requirements for mate of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Service requirements for mate of Great Lakes and inland... Professional Requirements for Deck Officers § 11.454 Service requirements for mate of Great Lakes and inland... applicant for an endorsement as mate of Great Lakes and inland steam or motor vessels of not more than 200...

  16. 46 CFR 11.442 - Requirements for master of Great Lakes and inland self-propelled vessels of less than 1,600 GRT.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Requirements for master of Great Lakes and inland self... Requirements for National Deck Officer Endorsements § 11.442 Requirements for master of Great Lakes and inland... for an endorsement as master of Great Lakes and inland self-propelled vessels of less than 1,600 GRT...

  17. 46 CFR 11.431 - Tonnage requirements for Great Lakes and inland endorsements for vessels of 1,600 GRT or more.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Tonnage requirements for Great Lakes and inland... Requirements for National Deck Officer Endorsements § 11.431 Tonnage requirements for Great Lakes and inland endorsements for vessels of 1,600 GRT or more. (a) All required experience for Great Lakes and inland unlimited...

  18. 46 CFR 11.454 - Service requirements for mate of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Service requirements for mate of Great Lakes and inland... Professional Requirements for Deck Officers § 11.454 Service requirements for mate of Great Lakes and inland... applicant for an endorsement as mate of Great Lakes and inland steam or motor vessels of not more than 200...

  19. 46 CFR 11.446 - Requirements for master of Great Lakes and inland self-propelled vessels of less than 500 GRT.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Requirements for master of Great Lakes and inland self... Requirements for National Deck Officer Endorsements § 11.446 Requirements for master of Great Lakes and inland... for an endorsement as master of Great Lakes and inland self-propelled vessels of less than 500 GRT is...

  20. 46 CFR 11.444 - Service requirements for mate of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Service requirements for mate of Great Lakes and inland... Professional Requirements for Deck Officers § 11.444 Service requirements for mate of Great Lakes and inland... applicant for an endorsement as mate of Great Lakes and inland steam or motor vessels of not more than 1600...

  1. 46 CFR 11.444 - Service requirements for mate of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Service requirements for mate of Great Lakes and inland... Professional Requirements for Deck Officers § 11.444 Service requirements for mate of Great Lakes and inland... applicant for an endorsement as mate of Great Lakes and inland steam or motor vessels of not more than 1600...

  2. FACTORS AFFECTING ENHANCED MERCURY BIOACCUMULATION IN INLAND LAKES OF ISLE ROYALE NATIONAL PARK, USA

    EPA Science Inventory

    We investigated factors causing mercury (Hg) concentrations in northern pike to exceed the consumption advisory level in some inland lakes of Isle Royale National Park. Using Hg-clean techniques, we collected water, zooplankton, macroinvertebrates, and fishes in 1998 and 1999 fro...

  3. Tracking human footprints in Antarctica through passive sampling of polycyclic aromatic hydrocarbons in inland lakes.

    PubMed

    Yao, Yao; Meng, Xiang-Zhou; Wu, Chen-Chou; Bao, Lian-Jun; Wang, Feng; Wu, Feng-Chang; Zeng, Eddy Y

    2016-06-01

    Freely dissolved polycyclic aromatic hydrocarbons (PAHs) were monitored in seven inland lakes of Antarctica by a polyethylene (PE)-based passive sampling technique, with the objective of tracking human footprints. The measured concentrations of PAHs were in the range of 14-360 ng L(-1) with the highest values concentrated around the Russian Progress II Station, indicating the significance of human activities to the loading of PAHs in Antarctica. The concentrations of PAHs in the inland lakes were in the upper part of the PAHs levels in aquatic environments from remote and background regions across the globe. The composition profiles of PAHs indicated that PAHs in the inland lakes were derived mainly from local oil spills, which was corroborated by a large number of fuel spillage reports from ship and plane crash incidents in Antarctica during recent years. Clearly, local human activities, rather than long-range transport, are the dominant sources of PAH contamination to the inland lakes. Finally, the present study demonstrates the efficacy of PE-based passive samplers for investigating PAHs in the aquatic environment of Antarctica under complex field conditions.

  4. Metagenomic Insights into the Uncultured Diversity and Physiology of Microbes in Four Hypersaline Soda Lake Brines

    PubMed Central

    Vavourakis, Charlotte D.; Ghai, Rohit; Rodriguez-Valera, Francisco; Sorokin, Dimitry Y.; Tringe, Susannah G.; Hugenholtz, Philip; Muyzer, Gerard

    2016-01-01

    Soda lakes are salt lakes with a naturally alkaline pH due to evaporative concentration of sodium carbonates in the absence of major divalent cations. Hypersaline soda brines harbor microbial communities with a high species- and strain-level archaeal diversity and a large proportion of still uncultured poly-extremophiles compared to neutral brines of similar salinities. We present the first “metagenomic snapshots” of microbial communities thriving in the brines of four shallow soda lakes from the Kulunda Steppe (Altai, Russia) covering a salinity range from 170 to 400 g/L. Both amplicon sequencing of 16S rRNA fragments and direct metagenomic sequencing showed that the top-level taxa abundance was linked to the ambient salinity: Bacteroidetes, Alpha-, and Gamma-proteobacteria were dominant below a salinity of 250 g/L, Euryarchaeota at higher salinities. Within these taxa, amplicon sequences related to Halorubrum, Natrinema, Gracilimonas, purple non-sulfur bacteria (Rhizobiales, Rhodobacter, and Rhodobaca) and chemolithotrophic sulfur oxidizers (Thioalkalivibrio) were highly abundant. Twenty-four draft population genomes from novel members and ecotypes within the Nanohaloarchaea, Halobacteria, and Bacteroidetes were reconstructed to explore their metabolic features, environmental abundance and strategies for osmotic adaptation. The Halobacteria- and Bacteroidetes-related draft genomes belong to putative aerobic heterotrophs, likely with the capacity to ferment sugars in the absence of oxygen. Members from both taxonomic groups are likely involved in primary organic carbon degradation, since some of the reconstructed genomes encode the ability to hydrolyze recalcitrant substrates, such as cellulose and chitin. Putative sodium-pumping rhodopsins were found in both a Flavobacteriaceae- and a Chitinophagaceae-related draft genome. The predicted proteomes of both the latter and a Rhodothermaceae-related draft genome were indicative of a “salt-in” strategy of

  5. Metagenomic Insights into the Uncultured Diversity and Physiology of Microbes in Four Hypersaline Soda Lake Brines

    DOE PAGES

    Vavourakis, Charlotte D.; Ghai, Rohit; Rodriguez-Valera, Francisco; ...

    2016-02-25

    Soda lakes are salt lakes with a naturally alkaline pH due to evaporative concentration of sodium carbonates in the absence of major divalent cations. Hypersaline soda brines harbor microbial communities with a high species- and strain-level archaeal diversity and a large proportion of still uncultured poly-extremophiles compared to neutral brines of similar salinities. We present the first "metagenomic snapshots" of microbial communities thriving in the brines of four shallow soda lakes from the Kulunda Steppe (Altai, Russia) covering a salinity range from 170 to 400 g/L. Both amplicon sequencing of 16S rRNA fragments and direct metagenomic sequencing showed that themore » top-level taxa abundance was linked to the ambient salinity: Bacteroidetes, Alpha-, and Gamma-proteobacteria were dominant below a salinity of 250 g/L, Euryarchaeota at higher salinities. Within these taxa, amplicon sequences related to Halorubrum, Natrinema, Gracilimonas, purple non-sulfur bacteria (Rhizobiales, Rhodobacter, and Rhodobaca) and chemolithotrophic sulfur oxidizers (Thioalkalivibrio) were highly abundant. Twenty-four draft population genomes from novel members and ecotypes within the Nanohaloarchaea, Halobacteria, and Bacteroidetes were reconstructed to explore their metabolic features, environmental abundance and strategies for osmotic adaptation. The Halobacteria- and Bacteroidetes-related draft genomes belong to putative aerobic heterotrophs, likely with the capacity to ferment sugars in the absence of oxygen. Members from both taxonomic groups are likely involved in primary organic carbon degradation, since some of the reconstructed genomes encode the ability to hydrolyze recalcitrant substrates, such as cellulose and chitin. Putative sodium-pumping rhodopsins were found in both a Flavobacteriaceae- and a Chitinophagaceae-related draft genome. The predicted proteomes of both the latter and a Rhodothermace ae-related draft genome were indicative of a "salt-in" strategy of

  6. Metagenomic Insights into the Uncultured Diversity and Physiology of Microbes in Four Hypersaline Soda Lake Brines

    SciTech Connect

    Vavourakis, Charlotte D.; Ghai, Rohit; Rodriguez-Valera, Francisco; Sorokin, Dimitry Y.; Tringe, Susannah G.; Hugenholtz, Philip; Muyzer, Gerard

    2016-02-25

    Soda lakes are salt lakes with a naturally alkaline pH due to evaporative concentration of sodium carbonates in the absence of major divalent cations. Hypersaline soda brines harbor microbial communities with a high species- and strain-level archaeal diversity and a large proportion of still uncultured poly-extremophiles compared to neutral brines of similar salinities. We present the first "metagenomic snapshots" of microbial communities thriving in the brines of four shallow soda lakes from the Kulunda Steppe (Altai, Russia) covering a salinity range from 170 to 400 g/L. Both amplicon sequencing of 16S rRNA fragments and direct metagenomic sequencing showed that the top-level taxa abundance was linked to the ambient salinity: Bacteroidetes, Alpha-, and Gamma-proteobacteria were dominant below a salinity of 250 g/L, Euryarchaeota at higher salinities. Within these taxa, amplicon sequences related to Halorubrum, Natrinema, Gracilimonas, purple non-sulfur bacteria (Rhizobiales, Rhodobacter, and Rhodobaca) and chemolithotrophic sulfur oxidizers (Thioalkalivibrio) were highly abundant. Twenty-four draft population genomes from novel members and ecotypes within the Nanohaloarchaea, Halobacteria, and Bacteroidetes were reconstructed to explore their metabolic features, environmental abundance and strategies for osmotic adaptation. The Halobacteria- and Bacteroidetes-related draft genomes belong to putative aerobic heterotrophs, likely with the capacity to ferment sugars in the absence of oxygen. Members from both taxonomic groups are likely involved in primary organic carbon degradation, since some of the reconstructed genomes encode the ability to hydrolyze recalcitrant substrates, such as cellulose and chitin. Putative sodium-pumping rhodopsins were found in both a Flavobacteriaceae- and a Chitinophagaceae-related draft genome. The predicted proteomes of both the latter and a Rhodothermace ae-related draft genome were indicative of a "salt-in" strategy of osmotic

  7. Metagenomic Insights into the Uncultured Diversity and Physiology of Microbes in Four Hypersaline Soda Lake Brines.

    PubMed

    Vavourakis, Charlotte D; Ghai, Rohit; Rodriguez-Valera, Francisco; Sorokin, Dimitry Y; Tringe, Susannah G; Hugenholtz, Philip; Muyzer, Gerard

    2016-01-01

    Soda lakes are salt lakes with a naturally alkaline pH due to evaporative concentration of sodium carbonates in the absence of major divalent cations. Hypersaline soda brines harbor microbial communities with a high species- and strain-level archaeal diversity and a large proportion of still uncultured poly-extremophiles compared to neutral brines of similar salinities. We present the first "metagenomic snapshots" of microbial communities thriving in the brines of four shallow soda lakes from the Kulunda Steppe (Altai, Russia) covering a salinity range from 170 to 400 g/L. Both amplicon sequencing of 16S rRNA fragments and direct metagenomic sequencing showed that the top-level taxa abundance was linked to the ambient salinity: Bacteroidetes, Alpha-, and Gamma-proteobacteria were dominant below a salinity of 250 g/L, Euryarchaeota at higher salinities. Within these taxa, amplicon sequences related to Halorubrum, Natrinema, Gracilimonas, purple non-sulfur bacteria (Rhizobiales, Rhodobacter, and Rhodobaca) and chemolithotrophic sulfur oxidizers (Thioalkalivibrio) were highly abundant. Twenty-four draft population genomes from novel members and ecotypes within the Nanohaloarchaea, Halobacteria, and Bacteroidetes were reconstructed to explore their metabolic features, environmental abundance and strategies for osmotic adaptation. The Halobacteria- and Bacteroidetes-related draft genomes belong to putative aerobic heterotrophs, likely with the capacity to ferment sugars in the absence of oxygen. Members from both taxonomic groups are likely involved in primary organic carbon degradation, since some of the reconstructed genomes encode the ability to hydrolyze recalcitrant substrates, such as cellulose and chitin. Putative sodium-pumping rhodopsins were found in both a Flavobacteriaceae- and a Chitinophagaceae-related draft genome. The predicted proteomes of both the latter and a Rhodothermaceae-related draft genome were indicative of a "salt-in" strategy of osmotic

  8. Seasonal fluctuations in ionic concentrations drive microbial succession in a hypersaline lake community

    PubMed Central

    Podell, Sheila; Emerson, Joanne B; Jones, Claudia M; Ugalde, Juan A; Welch, Sue; Heidelberg, Karla B; Banfield, Jillian F; Allen, Eric E

    2014-01-01

    Microbial community succession was examined over a two-year period using spatially and temporally coordinated water chemistry measurements, metagenomic sequencing, phylogenetic binning and de novo metagenomic assembly in the extreme hypersaline habitat of Lake Tyrrell, Victoria, Australia. Relative abundances of Haloquadratum-related sequences were positively correlated with co-varying concentrations of potassium, magnesium and sulfate, but not sodium, chloride or calcium ions, while relative abundances of Halorubrum, Haloarcula, Halonotius, Halobaculum and Salinibacter-related sequences correlated negatively with Haloquadratum and these same ionic factors. Nanohaloarchaea and Halorhabdus-related sequence abundances were inversely correlated with each other, but not other taxonomic groups. These data, along with predicted gene functions from nearly-complete assembled population metagenomes, suggest different ecological phenotypes for Nanohaloarchaea and Halorhabdus-related strains versus other community members. Nucleotide percent G+C compositions were consistently lower in community metagenomic reads from summer versus winter samples. The same seasonal G+C trends were observed within taxonomically binned read subsets from each of seven different genus-level archaeal groups. Relative seasonal abundances were also linked to percent G+C for assembled population genomes. Together, these data suggest that extreme ionic conditions may exert selective pressure on archaeal populations at the level of genomic nucleotide composition, thus contributing to seasonal successional processes. Despite the unavailability of cultured representatives for most of the organisms identified in this study, effective coordination of physical and biological measurements has enabled discovery and quantification of unexpected taxon-specific, environmentally mediated factors influencing microbial community structure. PMID:24335829

  9. Seasonal fluctuations in ionic concentrations drive microbial succession in a hypersaline lake community.

    PubMed

    Podell, Sheila; Emerson, Joanne B; Jones, Claudia M; Ugalde, Juan A; Welch, Sue; Heidelberg, Karla B; Banfield, Jillian F; Allen, Eric E

    2014-05-01

    Microbial community succession was examined over a two-year period using spatially and temporally coordinated water chemistry measurements, metagenomic sequencing, phylogenetic binning and de novo metagenomic assembly in the extreme hypersaline habitat of Lake Tyrrell, Victoria, Australia. Relative abundances of Haloquadratum-related sequences were positively correlated with co-varying concentrations of potassium, magnesium and sulfate, but not sodium, chloride or calcium ions, while relative abundances of Halorubrum, Haloarcula, Halonotius, Halobaculum and Salinibacter-related sequences correlated negatively with Haloquadratum and these same ionic factors. Nanohaloarchaea and Halorhabdus-related sequence abundances were inversely correlated with each other, but not other taxonomic groups. These data, along with predicted gene functions from nearly-complete assembled population metagenomes, suggest different ecological phenotypes for Nanohaloarchaea and Halorhabdus-related strains versus other community members. Nucleotide percent G+C compositions were consistently lower in community metagenomic reads from summer versus winter samples. The same seasonal G+C trends were observed within taxonomically binned read subsets from each of seven different genus-level archaeal groups. Relative seasonal abundances were also linked to percent G+C for assembled population genomes. Together, these data suggest that extreme ionic conditions may exert selective pressure on archaeal populations at the level of genomic nucleotide composition, thus contributing to seasonal successional processes. Despite the unavailability of cultured representatives for most of the organisms identified in this study, effective coordination of physical and biological measurements has enabled discovery and quantification of unexpected taxon-specific, environmentally mediated factors influencing microbial community structure.

  10. Rhodococcus sovatensis sp. nov., an actinomycete isolated from the hypersaline and heliothermal Lake Ursu.

    PubMed

    Táncsics, András; Máthé, István; Benedek, Tibor; Tóth, Erika M; Atasayar, Ewelina; Spröer, Cathrin; Márialigeti, Károly; Felföldi, Tamás; Kriszt, Balázs

    2017-02-01

    A Gram-stain-positive, strictly aerobic, mesophilic bacterium, designated H004T, was isolated from a water sample of the hypersaline and heliothermal Lake Ursu, Sovata, Romania. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain H004T formed a distinct phyletic lineage within the genus Rhodococcus. It shared the highest 16S rRNA gene sequence similarity with Rhodococcus yunnanensis YIM 70056T (98.80 %), followed by Rhodococcus fascians LMG 3623T (98.73 %), Rhodococcus cercidiphylli YIM 65003T (98.73 %), Rhodococcus cerastii C5T (98.58 %) and Rhodococcus kyotonensis DS472T (98.53 %). The alkB-based phylogenetic analysis further confirmed that this strain constitutes a highly unique lineage within the genus. Chemotaxonomic characteristics, including the predominant fatty acids acids C15 : 0, C18 : 1ω9c, C19 : 1ω11c/C19 : 1ω9c and C16 : 1ω7c/iso-C15 : 0 2-OH, the major quinone MK-8(H2), the presence of mycolic acids and cell-wall chemotype IV were also consistent with the properties of members of the genus Rhodococcus. The DNA G+C content of strain H004T was 65.4 mol%. The results of DNA-DNA hybridization analyses with the closest relatives, in combination with the alkB-based phylogenetic analysis, as well as the chemotaxonomic and physiological data, demonstrated that isolate H004T represents a novel species of the genus Rhodococcus, for which the name Rhodococcus sovatensissp. nov. is proposed. The type strain is H004T (=DSM 102881T=NCAIM B.02632T).

  11. Impact of solar radiation on bacterioplankton in Laguna Vilama, a hypersaline Andean lake (4650 m)

    NASA Astrophysics Data System (ADS)

    FaríAs, MaríA. Eugenia; FernáNdez-Zenoff, Verónica; Flores, Regina; OrdóñEz, Omar; EstéVez, Cristina

    2009-06-01

    Laguna Vilama is a hypersaline Lake located at 4660 m altitude in the northwest of Argentina high up in the Andean Puna. The impact of ultraviolet (UV) radiation on bacterioplankton was studied by collecting samples at different times of the day. Molecular analysis (DGGE) showed that the bacterioplankton community is characterized by Gamma-proteobacteria (Halomonas sp., Marinobacter sp.), Alpha-proteobacteria (Roseobacter sp.), HGC (Agrococcus jenensis and an uncultured bacterium), and CFB (uncultured Bacteroidetes). During the day, minor modifications in bacterial diversity such as intensification of Bacteroidetes' signal and an emergence of Gamma-proteobacteria (Marinobacter flavimaris) were observed after solar exposure. DNA damage, measured as an accumulation of Cyclobutane Pyrimidine Dimers (CPDs), in bacterioplankton and naked DNA increased from 100 CPDs MB-1 at 1200 local time (LT) to 300 CPDs MB-1 at 1600 LT, and from 80 CPDs MB-1 at 1200 LT to 640 CPDs MB-1 at 1600 LT, respectively. In addition, pure cultures of Pseudomonas sp. V1 and Brachybacterium sp. V5, two bacteria previously isolated from this environment, were exposed simultaneously with the community, and viability of both strains diminished after solar exposure. No CPD accumulation was observed in either of the exposed cultures, but an increase in mutagenesis was detected in V5. Of both strains only Brachybacterium sp. V5 showed CPD accumulation in naked DNA. These results suggest that the bacterioplankton community is well adapted to this highly solar irradiated environment showing little accumulation of CPDs and few changes in the community composition. They also demonstrate that these microorganisms contain efficient mechanisms against UV damage.

  12. Sodium toxicity and pathology associated with exposure of waterfowl to hypersaline playa lakes of southeast New Mexico

    USGS Publications Warehouse

    Meteyer, C.U.; Dubielzig, R.D.; Dein, F.J.; Baeten, L.A.; Moore, M.K.; Jehl, J.R.; Wesenberg, K.E.

    1997-01-01

    Cause of mortality was studied in waterfowl in hypersaline playa lakes of southeast New Mexico during spring and fall migration. Mortality was not common in wild ducks resting on the playas during good weather. However, when birds remained on the lakes for prolonged periods of time, such as during experimental trials and stormy weather, a heavy layer of salt precipitated on their feathers. Sodium toxicity was the cause of death for all experimental mallards housed on playa water and for 50% of the wild waterfowl found moribund or dead during the spring of 1995. Gross lesions included heavy salt precipitation on the feathers, ocular lens opacities, deeply congested brains, and dilated, thin-walled, fluid-filled cloacae. Microscopic lesions in the more severely affected birds included liquefaction of ocular lens cortex with lens fiber swelling and multifocal to diffuse ulcerative conjunctivitis with severe granulocytic inflammation, edema, and granulocytic vasculitis resulting in thrombosis. Inflammation similar to that seen in the conjunctiva occasionally involved the mucosa of the mouth, pharynx, nasal turbinates, cloaca, and bursa. Transcorneal movement of water in response to the hypersaline conditions on the playa lakes or direct contact with salt crystals could induce anterior segment dehydration of the aqueous humor and increased osmotic pressure on the lens, leading to cataract formation.

  13. Syntrophic associations from hypersaline soda lakes converting organic acids and alcohols to methane at extremely haloalkaline conditions.

    PubMed

    Sorokin, Dimitry Y; Abbas, Ben; Geleijnse, Mitchell; Kolganova, Tatjana V; Kleerebezem, Robbert; van Loosdrecht, Mark C M

    2016-09-01

    Until now anaerobic oxidation of VFA at high salt-pH has been demonstrated only at sulfate-reducing conditions. Here, we present results of a microbiological investigation of anaerobic conversion of organic acids and alcohols at methanogenic conditions by syntrophic associations enriched from hypersaline soda lakes in Central Asia. Sediment incubation experiments showed active, albeit very slow, methane formation from acetate, propionate, butyrate and C2 C4 alcohols at pH 10 and various levels of salinity. Enrichments of syntrophic associations using hydrogenotrophic members of the genus Methanocalculus from soda lakes as partners resulted in several highly enriched cultures converting acetate, propionate, butyrate, benzoate and EtOH to methane. Most syntrophs belonged to Firmicutes, while the propionate-oxidizer formed a novel lineage within the family Syntrophobacteraceae in the Deltaproteobacteria. The acetate-oxidizing syntroph was identified as 'Ca. Syntrophonatronum acetioxidans' previously found to oxidize acetate at sulfate-reducing conditions up to salt-saturating concentrations. Butyrate and a benzoate-degrading syntrophs represent novel genus-level lineages in Syntrophomonadales which are proposed as Candidatus taxons 'Syntrophobaca', 'Syntrophocurvum' and 'Syntropholuna'. Overall, despite very slow growth, the results indicated the presence of a functionally competent syntrophic community in hypersaline soda lakes, capable of efficient oxidation of fermentation products to methane at extremely haloalkaline conditions.

  14. Microbial source tracking markers at three inland recreational lakes in Ohio, 2011

    USGS Publications Warehouse

    Francy, Donna S.; Stelzer, Erin A.

    2012-01-01

    During the 2011 recreational season, samples were collected for E. coli and microbial source tracking (MST) marker concentrations to begin to understand potential sources of fecal contamination at three inland recreational lakes in Ohio - Buckeye, Atwood, and Tappan Lakes. The results from 32 regular samples, 4 field blanks, and 7 field replicates collected at 5 sites are presented in this report. At the three lakes, the ruminant-associated marker was found most often (57-73 percent of samples) but at estimated quantities, followed by the dog-associated marker (30-43 percent of samples). The human-associated marker was found in 14 and 50 percent of samples from Atwood and Tappan Lakes, respectively, but was not found in any samples from the two Buckeye Lake sites. The gull-associated marker was detected in only two samples, both from Tappan Lake.

  15. Comparison of bacterial biodiversity and enzyme production in three hypersaline lakes; urmia, howz-soltan and aran-bidgol.

    PubMed

    Babavalian, Hamid; Amoozegar, Mohammad Ali; Zahraei, Shirin; Rohban, Rokhsareh; Shakeri, Fatemeh; Moghaddam, Mehrdad Moosazadeh

    2014-12-01

    This research is a comparative study on the diversity of halophilic bacteria with hydrolytic activities in three significant hypersaline lakes; Urmia in the northwest and Howz-Soltan and Aran-Bidgol in the central desert in Iran. Isolated strains from these saline lakes were found to be halotolerant, moderately and extremely halophilic bacteria. The bacteria in each saline lake were able to produce different hydrolytic enzymes including amylase, protease, lipase, DNase, inulinase, xylanase, carboxy methyl cellulase, pectinase and pullulanase. 188, 302, 91 halophilic strains were isolated from Urmia Lake, Howz-Soltan and Aran-Bidgol playa, respectively. The numbers of Gram-positive strains were more than Gram-negatives, and among Gram-positive bacteria; spore-forming bacilli were most abundant. Due to the unique physico-chemical conditions of the lake environments, the hydrolytic activities of isolated strains were significantly different. For instance, isolated strains from Howz-Soltan playa did not produce pectinase, DNase, amylase, lipase and inulinase, while the isolates from Aran-Bidgol playa had a great ability to produce pectinase and DNase. The strains from Urmia Lake were also good producers of DNase but failed to show any chitinase activity. The diversity of halophilic bacteria from the mentioned three saline lakes was also determined using PCR-amplified 16S rRNA followed by phylogenetic analysis of the partial 16S rRNA sequences.

  16. Heterogeneous inland lake seasonality and the associated cryosphere hydrology on the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Lei, Y.; Yao, T.

    2016-12-01

    The recent growth of inland lakes on the Tibetan Plateau (TP) has been extensively investigated; however, seasonal lake water level fluctuations and their association with cryosphere hydrology in this remote, high-altitude region are less understood. Based on extensive in-situ observations and satellite altimetry data between 2010 and 2014, we show that lake level seasonality is heterogeneous between the northwestern TP and other regions on the TP in response to differences in precipitation, lake evaporation, lake ice duration, and glacier coverage. During warm season (June-September), lake levels increased considerably, whereas during cold season (October to May) lake levels decreased considerably on the central and northeastern TP, remained nearly stable (or decreased slightly) on the northern TP, and increased considerably on the northwestern TP. Comparison between lake level changes and gravity data indicates that glacier mass loss may have significantly contributed to warm-season lake level increases on the northwestern TP, while monsoon precipitation played a more important role in other regions. This study may shed light on identifying the contribution of monsoon precipitation, snowfall and glacier melting on lake water budget and further understanding the causes of the recent lake growth on the TP.

  17. 46 CFR 30.01-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes Routes-TB/OC.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Ocean or unlimited coastwise vessels on inland and Great... VESSELS GENERAL PROVISIONS Administration § 30.01-7 Ocean or unlimited coastwise vessels on inland and Great Lakes Routes—TB/OC. (a) Vessels inspected and certificated for ocean or unlimited coastwise routes...

  18. 46 CFR 188.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) OCEANOGRAPHIC RESEARCH VESSELS GENERAL PROVISIONS Application § 188.05-7 Ocean or unlimited coastwise vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited coastwise...

  19. 46 CFR 167.01-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS General Provisions § 167.01-7 Ocean or unlimited coastwise vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited...

  20. 46 CFR 30.01-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes Routes-TB/OC.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Ocean or unlimited coastwise vessels on inland and Great... VESSELS GENERAL PROVISIONS Administration § 30.01-7 Ocean or unlimited coastwise vessels on inland and Great Lakes Routes—TB/OC. (a) Vessels inspected and certificated for ocean or unlimited coastwise routes...

  1. 46 CFR 90.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) CARGO AND MISCELLANEOUS VESSELS GENERAL PROVISIONS Application § 90.05-7 Ocean or unlimited coastwise vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited...

  2. 46 CFR 90.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) CARGO AND MISCELLANEOUS VESSELS GENERAL PROVISIONS Application § 90.05-7 Ocean or unlimited coastwise vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited...

  3. 46 CFR 70.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes Routes.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) PASSENGER VESSELS GENERAL PROVISIONS Application § 70.05-7 Ocean or unlimited coastwise vessels on inland and Great Lakes Routes. (a) Vessels inspected and certificated for ocean or unlimited coastwise routes...

  4. 46 CFR 188.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) OCEANOGRAPHIC RESEARCH VESSELS GENERAL PROVISIONS Application § 188.05-7 Ocean or unlimited coastwise vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited coastwise...

  5. 46 CFR 70.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes Routes.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) PASSENGER VESSELS GENERAL PROVISIONS Application § 70.05-7 Ocean or unlimited coastwise vessels on inland and Great Lakes Routes. (a) Vessels inspected and certificated for ocean or unlimited coastwise routes...

  6. 46 CFR 70.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes Routes.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) PASSENGER VESSELS GENERAL PROVISIONS Application § 70.05-7 Ocean or unlimited coastwise vessels on inland and Great Lakes Routes. (a) Vessels inspected and certificated for ocean or unlimited coastwise routes...

  7. 46 CFR 70.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes Routes.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) PASSENGER VESSELS GENERAL PROVISIONS Application § 70.05-7 Ocean or unlimited coastwise vessels on inland and Great Lakes Routes. (a) Vessels inspected and certificated for ocean or unlimited coastwise routes...

  8. 46 CFR 167.01-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS General Provisions § 167.01-7 Ocean or unlimited coastwise vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited...

  9. 46 CFR 167.01-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS General Provisions § 167.01-7 Ocean or unlimited coastwise vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited...

  10. 46 CFR 167.01-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS General Provisions § 167.01-7 Ocean or unlimited coastwise vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited...

  11. 46 CFR 167.01-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS General Provisions § 167.01-7 Ocean or unlimited coastwise vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited...

  12. 46 CFR 188.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) OCEANOGRAPHIC RESEARCH VESSELS GENERAL PROVISIONS Application § 188.05-7 Ocean or unlimited coastwise vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited coastwise...

  13. 46 CFR 30.01-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes Routes-TB/OC.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Ocean or unlimited coastwise vessels on inland and Great... VESSELS GENERAL PROVISIONS Administration § 30.01-7 Ocean or unlimited coastwise vessels on inland and Great Lakes Routes—TB/OC. (a) Vessels inspected and certificated for ocean or unlimited coastwise routes...

  14. 46 CFR 188.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) OCEANOGRAPHIC RESEARCH VESSELS GENERAL PROVISIONS Application § 188.05-7 Ocean or unlimited coastwise vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited coastwise...

  15. 46 CFR 188.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) OCEANOGRAPHIC RESEARCH VESSELS GENERAL PROVISIONS Application § 188.05-7 Ocean or unlimited coastwise vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited coastwise...

  16. 46 CFR 70.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes Routes.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) PASSENGER VESSELS GENERAL PROVISIONS Application § 70.05-7 Ocean or unlimited coastwise vessels on inland and Great Lakes Routes. (a) Vessels inspected and certificated for ocean or unlimited coastwise routes...

  17. 46 CFR 90.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) CARGO AND MISCELLANEOUS VESSELS GENERAL PROVISIONS Application § 90.05-7 Ocean or unlimited coastwise vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited...

  18. 46 CFR 30.01-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes Routes-TB/OC.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Ocean or unlimited coastwise vessels on inland and Great... VESSELS GENERAL PROVISIONS Administration § 30.01-7 Ocean or unlimited coastwise vessels on inland and Great Lakes Routes—TB/OC. (a) Vessels inspected and certificated for ocean or unlimited coastwise routes...

  19. 46 CFR 90.05-7 - Ocean or unlimited coastwise vessels on inland and Great Lakes routes.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Ocean or unlimited coastwise vessels on inland and Great...) CARGO AND MISCELLANEOUS VESSELS GENERAL PROVISIONS Application § 90.05-7 Ocean or unlimited coastwise vessels on inland and Great Lakes routes. (a) Vessels inspected and certificated for ocean or unlimited...

  20. 46 CFR 11.442 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... inland steam or motor vessels of not more than 1600 gross tons. 11.442 Section 11.442 Shipping COAST... Lakes and inland steam or motor vessels of not more than 1600 gross tons. The minimum service required to qualify an applicant for an endorsement as master of Great Lakes and inland steam or motor...

  1. 46 CFR 11.442 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... inland steam or motor vessels of not more than 1600 gross tons. 11.442 Section 11.442 Shipping COAST... Lakes and inland steam or motor vessels of not more than 1600 gross tons. The minimum service required to qualify an applicant for an endorsement as master of Great Lakes and inland steam or motor...

  2. Water level variation of Inland lakes on the southeasten of Tibetan Plateau in 1972-2012

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Lei, L.

    2014-12-01

    Lake water level variation directly records the process of water storage balance in the basin, which is a quite sensitive response to the climate change. We obtained the long-time lake area and level series of the five typical lakes from 1972 to 2012 in the Tibetan Plateau, and analyzed the variation of lake levels in recent 40 years, using the multi-source remote sensing data. The results show that the lake level of three inland lakes ( Pumo Yumco , Taro Co, Zhari Namco)have rose 0.89m, 0.70m,0.40m respectively ,while the two lakes (Peiku Co, Mapang Yumco) showed decreasing tendency, the changes is -1.696m,-0,153m. On the whole, the five lakes have experienced more remarkable changes in 2000-2012 than 1976-1999. In terms of spatial variations, the three lakes which located in south Tibetan Plateau, Peiku Co and Mapang Yumco, have show the consistent variation trend, as well as the other two lakes, Taro Co and Zhari Namco.

  3. Characterization of Sporohalobacter salinus sp. nov., an anaerobic, halophilic, fermentative bacterium isolated from a hypersaline lake.

    PubMed

    Ben Abdallah, Manel; Karray, Fatma; Mhiri, Najla; Cayol, Jean-Luc; Tholozan, Jean-Luc; Alazard, Didier; Sayadi, Sami

    2015-02-01

    Halophilic, obligately anaerobic, Gram-stain-negative bacterial strains were isolated from a sediment sample taken from under the salt crust of El-Jerid hypersaline lake in southern Tunisia by using tryptone or glucose as the substrate. One strain, CEJFT1B(T), was characterized phenotypically and phylogenetically. Cells were non-motile, non-spore-forming, short rods. Strain CEJFT1B(T) was able to grow in the presence of 5-30 % (w/v) NaCl (optimum 20 %) and at 30-60 °C (optimum 45 °C). It grew at pH 5.5-7.8 and the optimum pH for growth was 6.8. The isolate required yeast extract for growth. Substrates utilized by strain CEJFT1B(T) as the sole carbon source included glucose, fructose, sucrose, pyruvate, Casamino acids and starch. Individual amino acids such as glutamate, lysine, methionine, serine, tyrosine, and amino acid mixtures formed by the Stickland reaction such as alanine-glycine, valine-proline, leucine-proline, isoleucine-proline were also utilized. Products of glucose fermentation were acetate (major product), butyrate, H2 and CO2. The genomic DNA G+C content of strain CEJFT1B(T) was 32.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CEJFT1B(T) should be assigned to the genus Sporohalobacter. The sequence similarity between strain CEJFT1B(T) and Sporohalobacter lortetii was 98.5 %, but DNA-DNA hybridization between the two strains revealed a relatedness value of 56.4 %, indicating that they are not related at the species level. The combination of phylogenetic analysis, DNA-DNA hybridization data, and differences in substrate utilization support the view that strain CEJFT1B(T) represents a novel species of the genus Sporohalobacter, for which the name Sporohalobacter salinus sp. nov. is proposed. The type strain is CEJFT1B(T) ( = DSM 26781(T) = JCM 19279(T)).

  4. Climate change driven water budget dynamics of a Tibetan inland lake

    NASA Astrophysics Data System (ADS)

    Li, Binquan; Zhang, Jianyun; Yu, Zhongbo; Liang, Zhongmin; Chen, Li; Acharya, Kumud

    2017-03-01

    Understanding the hydrologic processes of inland lake basins in the Tibetan Plateau (TP) could provide insights into the responses of Tibetan lake dynamics to climate change. An efficient approach for this purpose is to represent complex hydrologic behaviors of such Tibetan lake watersheds with plausible hydrologic models. In this study, water level fluctuations of Lake Nam Co, an inland lake in the central TP, were investigated using a lumped lake-watershed model. The degree-day factor method was introduced to improve the model applicability in glacier-covered basins. The model simulated the hydrologic processes as well as the lake water budget. Remote sensing images (Landsat MSS, TM, ETM + and OLI) from 1972 to 2015 were used to identify the glacier and lake boundaries. Multisource climate data (e.g., ground point observation, 0.25o gridded APHRODITE and TRMM 3B42 v7 precipitation products) were used to drive the hydrologic model at a monthly time step. Results of trend analysis showed that basin-wide annual air temperature increased by the rate 0.04 °C/yr from 1961 to 2015. Mean annual precipitation slowly increased from 1961 to the mid-1990s, and then rapidly increased from the late-1990s to the mid-2000s, and finally obviously decreased after the mid-2000s. As a response to climate change, glaciers decreased by 62.69 km2 (29%) and lake area increased by 91.83 km2 (4.7%) from 1972 to 2015. The analysis of lake water budget suggested that, the total basin runoff and on-lake precipitation contributed 1.36 km3/yr (66%) and 0.7 km3/yr (34%), respectively, to mean annual water gain of the lake. Glacier runoff was 14% of the basin runoff and 10% of the total water gain of the lake. The percentages of lake evaporation, water seepage and water surplus were 65%, 20% and 15%, respectively. Lake level increased with the rate of 0.14 m/yr for the study period 1961-2015. It could be concluded that precipitation was the dominant controlling factor for the different

  5. Genome Sequence of Sphingomonas sp. S17, Isolated from an Alkaline, Hyperarsenic, and Hypersaline Volcano-Associated Lake at High Altitude in the Argentinean Puna ▿

    PubMed Central

    Farias, Maria Eugenia; Revale, Santiago; Mancini, Estefania; Ordoñez, Omar; Turjanski, Adrian; Cortez, Néstor; Vazquez, Martin P.

    2011-01-01

    The high-altitude Andean lakes (HAAL) in the Argentinean Puna-high Andes region represent an almost unexplored ecosystem exposed to extreme conditions (high UV irradiation, hypersalinity, drastic temperature changes, desiccation, and high pH). Here we present the first genome sequence, a Sphingomonas sp., isolated from this extreme environment. PMID:21602338

  6. Genome sequence of Sphingomonas sp. S17, isolated from an alkaline, hyperarsenic, and hypersaline volcano-associated lake at high altitude in the Argentinean Puna.

    PubMed

    Farias, Maria Eugenia; Revale, Santiago; Mancini, Estefania; Ordoñez, Omar; Turjanski, Adrian; Cortez, Néstor; Vazquez, Martin P

    2011-07-01

    The high-altitude Andean lakes (HAAL) in the Argentinean Puna-high Andes region represent an almost unexplored ecosystem exposed to extreme conditions (high UV irradiation, hypersalinity, drastic temperature changes, desiccation, and high pH). Here we present the first genome sequence, a Sphingomonas sp., isolated from this extreme environment.

  7. Phylogenetic Analysis of a Microbialite-Forming Microbial Mat from a Hypersaline Lake of the Kiritimati Atoll, Central Pacific

    PubMed Central

    Schneider, Dominik; Arp, Gernot; Reimer, Andreas; Reitner, Joachim; Daniel, Rolf

    2013-01-01

    On the Kiritimati atoll, several lakes exhibit microbial mat-formation under different hydrochemical conditions. Some of these lakes trigger microbialite formation such as Lake 21, which is an evaporitic, hypersaline lake (salinity of approximately 170‰). Lake 21 is completely covered with a thick multilayered microbial mat. This mat is associated with the formation of decimeter-thick highly porous microbialites, which are composed of aragonite and gypsum crystals. We assessed the bacterial and archaeal community composition and its alteration along the vertical stratification by large-scale analysis of 16S rRNA gene sequences of the nine different mat layers. The surface layers are dominated by aerobic, phototrophic, and halotolerant microbes. The bacterial community of these layers harbored Cyanobacteria (Halothece cluster), which were accompanied with known phototrophic members of the Bacteroidetes and Alphaproteobacteria. In deeper anaerobic layers more diverse communities than in the upper layers were present. The deeper layers were dominated by Spirochaetes, sulfate-reducing bacteria (Deltaproteobacteria), Chloroflexi (Anaerolineae and Caldilineae), purple non-sulfur bacteria (Alphaproteobacteria), purple sulfur bacteria (Chromatiales), anaerobic Bacteroidetes (Marinilabiacae), Nitrospirae (OPB95), Planctomycetes and several candidate divisions. The archaeal community, including numerous uncultured taxonomic lineages, generally changed from Euryarchaeota (mainly Halobacteria and Thermoplasmata) to uncultured members of the Thaumarchaeota (mainly Marine Benthic Group B) with increasing depth. PMID:23762495

  8. Phylogenetic analysis of a microbialite-forming microbial mat from a hypersaline lake of the Kiritimati atoll, Central Pacific.

    PubMed

    Schneider, Dominik; Arp, Gernot; Reimer, Andreas; Reitner, Joachim; Daniel, Rolf

    2013-01-01

    On the Kiritimati atoll, several lakes exhibit microbial mat-formation under different hydrochemical conditions. Some of these lakes trigger microbialite formation such as Lake 21, which is an evaporitic, hypersaline lake (salinity of approximately 170‰). Lake 21 is completely covered with a thick multilayered microbial mat. This mat is associated with the formation of decimeter-thick highly porous microbialites, which are composed of aragonite and gypsum crystals. We assessed the bacterial and archaeal community composition and its alteration along the vertical stratification by large-scale analysis of 16S rRNA gene sequences of the nine different mat layers. The surface layers are dominated by aerobic, phototrophic, and halotolerant microbes. The bacterial community of these layers harbored Cyanobacteria (Halothece cluster), which were accompanied with known phototrophic members of the Bacteroidetes and Alphaproteobacteria. In deeper anaerobic layers more diverse communities than in the upper layers were present. The deeper layers were dominated by Spirochaetes, sulfate-reducing bacteria (Deltaproteobacteria), Chloroflexi (Anaerolineae and Caldilineae), purple non-sulfur bacteria (Alphaproteobacteria), purple sulfur bacteria (Chromatiales), anaerobic Bacteroidetes (Marinilabiacae), Nitrospirae (OPB95), Planctomycetes and several candidate divisions. The archaeal community, including numerous uncultured taxonomic lineages, generally changed from Euryarchaeota (mainly Halobacteria and Thermoplasmata) to uncultured members of the Thaumarchaeota (mainly Marine Benthic Group B) with increasing depth.

  9. Monitoring variations of inland lakes in the arid region of Central Asia

    NASA Astrophysics Data System (ADS)

    Bai, Jie; Chen, Xi; Yang, Liao; Fang, Hui

    2012-06-01

    Inland lakes are the major surface water resource in the arid regions of Central Asia. Therefore, the surface area changes in inland lakes have been a sensitive indicator of climate changes and human activities, and have often been the focus of ecological and environmental research. This study aimed to monitor the changes in surface area of nine major lakes over a 32-year period. The water body was extracted from MSS images from the mid-1970s, TM images from the early 1990s, ETM + images in the late 1990s, and TM images in 2007. The results indicated that the total surface area of these nine lakes had decreased over time to 50.38% of the area, from 91402.06 km2 in 1975 to 46049.23 km2 in 2007. As the surface area of lakes in the western part of Central Asia was larger than that in the eastern part, the shrinking trend of lake area was more significant in the west than in the east. There was a varied reduction of closed lakes in flat regions. The most substantial decrease was in the surface area of closed lakes in flat regions. Most significantly, the area of the Aral Sea was reduced by 75.7% from its original area in 1975. The area of alpine lakes remained relatively stable; the change in surface area was less than 0.7% during the period 1975-2007. The area change in opened lakes with outlets was notably different from the other two types. The area of Zaysan had increased sharply by 5.85%, and that of Bosten had decreased by 9.1%. Sasykkol had hardly any changes in this period. Due to global climate warming, vapor transfer to the south via westerly winds had been blocked, resulting in a decrease of much-needed precipitation in the western parts of Turkmenistan, Uzbekistan, and Kazakhstan between 1970 and 2000. The decrease in precipitation and the increase in water consumption for agricultural irrigation resulted in the decrease of river runoff. Consequently, the area of inland lakes in Central Asia shrank over the past 32 years.

  10. Utilization of ERTS-1 data to monitor and classify eutrophication of inland lakes

    NASA Technical Reports Server (NTRS)

    Chase, P. E. (Principal Investigator)

    1972-01-01

    The author has identified the following significant results. Channel 7 is highly useful in surveying surface water in lakes, rivers, and large marshes. It is likely to miss detection of elliptically shaped bodies of 4 acres or less. Further, it is possible that the bodies are distorted and displaced because of lack of correction for sensor response time. These errors might not be critical because:(1) location accuracy is not essential to a surface water survey; and (2) an obviously distorted image is often not in error in excess of 5% The finding that Orchard Lake and other lakes in Oakland County have different densities in channels 4, 5, 6, and 7 is important because it implies that the lake wide water color average is different in the separate channels. Channels 6 and 7 were constant in tonal quality among all the lakes while channels 4 and 5 varied from lake to lake and in various parts of Orchard Lake. These findings are significant because it means that small inland lake color differences are recorded by the MSS even on a cloudy or hazy day. It also confirms that ERTS-1 is performing well enough to be used for correlation to ground truth and aircraft underflights.

  11. New insights into microbially induced sedimentary structures in alkaline hypersaline El Beida Lake, Wadi El Natrun, Egypt

    NASA Astrophysics Data System (ADS)

    Taher, Amany G.; Abdel-Motelib, Ali

    2015-10-01

    Microbially induced sedimentary structures (MISS) were studied in detail in the alkaline hypersaline El Beida Lake of Wadi El Natrun in the western desert sector of Egypt, based on field observations and sampling performed in 2013 and 2014. Geomorphologically, the lake can be subdivided into three zones, each with characteristic sedimentary and biosedimentary structures. The marginal elevated zone that borders the lake is characterized by thick blocky crusts devoid of microbial mats. The middle-lower supratidal zone has luxuriant microbial mats associated with knotty surfaces, mat cracks and wrinkle structures. A zone of ephemeral shallow pools and channels is characterized by reticulate surfaces, pinnacle mats, sieve-like surfaces, gas domes and mat chips. In the microbial mats, authigenic minerals include thenardite Na2SO4, trona Na3(CO3)(HCO3)•2H2O and halite NaCl. Scanning electron microscopy (SEM) analyses revealed that the minerals are closely associated with the MISS, suggesting some influence of microorganisms on mineral precipitation. Complex interactions between regional hydrological cycles and diagenetic processes imply low preservation potential. MISS signatures of such saline lakes can serve as key analogues for interpreting the geologic record.

  12. Hydrochemical and isotopes studies in a hypersaline wetland to define the hydrogeological conceptual model: Fuente de Piedra Lake (Malaga, Spain).

    PubMed

    Montalván, F J; Heredia, J; Ruiz, J M; Pardo-Igúzquiza, E; García de Domingo, A; Elorza, F J

    2017-01-15

    The Fuente de Piedra lake is a hypersaline wetland of great extension (13.5km(2)) and rich in aquatic birds and other species. It became therefore the third Spanish wetland to be included in the Ramsar convention and has been a "nature reserve" since 1984. The lake has an endorheic basin (150km(2)) with variable-density flows dominated by complex hydrogeological conditions. The traditional conceptualization of endorheic basins in semiarid climates considered that the brine in this hydric system was exclusively of evaporative origin and was placed only in the lake and its surrounding discharge area in the basin. Previous geophysical and hydrochemical studies identified different types of waters and brines. In this work, natural tracers (Cl(-), Br(-), Na(+), Mg(2+)) and environmental isotopes ((18)O, (2)H, (14)C, (13)C and (3)H) were employed to a) discriminate different types of brines according to their degree of evaporation and genesis, and b) to estimate residence times of brine waters and identify recharge areas of the different flow subsystems. A conceptual model of the hydrogeological system of the lake basin and its links to a regional karst system is proposed. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. An estimate of glacier melting contribution to inland lakes on Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Ye, Q.; Moholdt, G.; Yao, T.; Liu, S.; Zhang, Y.

    2014-12-01

    As it is known that continental glacier melting dramatically in a warmer climate and its mass loss contribute to the sea level rise, however, there are lots of inland lakes that receives glacier melting contributions to some extent, it is still not known how much melting water from glaciers to lakes overall on a global and regional view. On the Tibetan Plateau, there are four inland basins in contrast to six external catchments at the marginal plateau. With the same reference system, co-registration and bias/offsets correction, DEMs and ICESat/GLAS data were used to calculate glacier surface elevation changes, which includes the historical DEM at 1:250,000 in 1970s, SRTM DEM and ICESat/GLAS over the whole Tibetan Plateau. According to the 1st glacier inventory database by each glacier in different basins, glacier surface elevation changes were calculated, and glacier mass changes were evaluated. It shows that, for external catchments, glacier mass change was totalled by -9.5 ± 3.6 Gt a-1 during 1970s-2000, it was more negative during 2003-2009 (-14.9 ± 6.9 Gt a-1). It shows more melting glacier water runs into the sea in recent decade. However, it was obviously less than some previous studies in HMA, e.g. Gardner et al., 2013, glacier contributed to sea level rise by 26±12 Gt a-1 .While for internal basins overall, glacier mass change was totalled by -7.6 ± 2.3 Gt a-1 during 1970s-2000, however, it was less negative during 2003-2009 (-3.05± 1.4 Gt a-1). It seems that precipitation has increased in inland Tibet and there might be less glacier melting mass runs into inland lakes in recent decade.

  14. 46 CFR 11.452 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Service requirements for master of Great Lakes and... Professional Requirements for Deck Officers § 11.452 Service requirements for master of Great Lakes and inland... applicant for an endorsement as master of Great Lakes and inland steam or motor vessels of not more than 200...

  15. 46 CFR 11.452 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Service requirements for master of Great Lakes and... Professional Requirements for Deck Officers § 11.452 Service requirements for master of Great Lakes and inland... applicant for an endorsement as master of Great Lakes and inland steam or motor vessels of not more than 200...

  16. 46 CFR 11.456 - Requirements for limited master of Great Lakes and inland self-propelled vessels of less than 100...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Requirements for limited master of Great Lakes and... Great Lakes and inland self-propelled vessels of less than 100 GRT. (a) An endorsement as limited master for vessels of less than 100 GRT upon Great Lakes and inland waters may be issued to an applicant to...

  17. 46 CFR 11.452 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Service requirements for master of Great Lakes and... Professional Requirements for Deck Officers § 11.452 Service requirements for master of Great Lakes and inland... applicant for an endorsement as master of Great Lakes and inland steam or motor vessels of not more than 200...

  18. 46 CFR 11.455 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Service requirements for master of Great Lakes and... Professional Requirements for Deck Officers § 11.455 Service requirements for master of Great Lakes and inland... applicant for an endorsement as master of Great Lakes and inland steam or motor vessels of not more than 100...

  19. 46 CFR 11.455 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Service requirements for master of Great Lakes and... Professional Requirements for Deck Officers § 11.455 Service requirements for master of Great Lakes and inland... applicant for an endorsement as master of Great Lakes and inland steam or motor vessels of not more than 100...

  20. 46 CFR 11.446 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Service requirements for master of Great Lakes and... Professional Requirements for Deck Officers § 11.446 Service requirements for master of Great Lakes and inland... applicant for an endorsement as master of Great Lakes and inland steam or motor vessels of not more than 500...

  1. 46 CFR 11.455 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Service requirements for master of Great Lakes and... Professional Requirements for Deck Officers § 11.455 Service requirements for master of Great Lakes and inland... applicant for an endorsement as master of Great Lakes and inland steam or motor vessels of not more than 100...

  2. 46 CFR 11.433 - Service requirements for master of Great Lakes and inland steam or motor vessels of any gross tons.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Service requirements for master of Great Lakes and... Professional Requirements for Deck Officers § 11.433 Service requirements for master of Great Lakes and inland... endorsement as master of Great Lakes and inland steam or motor vessels of any gross tons is: (a) One year...

  3. 46 CFR 11.455 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Service requirements for master of Great Lakes and... Professional Requirements for Deck Officers § 11.455 Service requirements for master of Great Lakes and inland... applicant for an endorsement as master of Great Lakes and inland steam or motor vessels of not more than...

  4. 46 CFR 11.452 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Service requirements for master of Great Lakes and... Professional Requirements for Deck Officers § 11.452 Service requirements for master of Great Lakes and inland... applicant for an endorsement as master of Great Lakes and inland steam or motor vessels of not more than...

  5. Complete genome sequence of Desulfurivibrio alkaliphilus strain AHT2T, a haloalkaliphilic sulfidogen from Egyptian hypersaline alkaline lakes

    DOE PAGES

    Melton, Emily Denise; Sorokin, Dimitry Y.; Overmars, Lex; ...

    2016-09-08

    Desulfurivibrio alkaliphilus strain AHT2T is a strictly anaerobic sulfidogenic haloalkaliphile isolated from a composite sediment sample of eight hypersaline alkaline lakes in the Wadi al Natrun valley in the Egyptian Libyan Desert. D. alkaliphilus AHT2T is Gram-negative and belongs to the family Desulfobulbaceae within the Deltaproteobacteria. Here we report its genome sequence, which contains a 3.10 Mbp chromosome. Here, D. alkaliphilus AHT2T is adapted to survive under highly alkaline and moderately saline conditions and therefore, is relevant to the biotechnology industry and life under extreme conditions. For these reasons, D. alkaliphilus AHT2T was sequenced by the DOE Joint Genome Institutemore » as part of the Community Science Program.« less

  6. Complete genome sequence of Desulfurivibrio alkaliphilus strain AHT2(T), a haloalkaliphilic sulfidogen from Egyptian hypersaline alkaline lakes.

    PubMed

    Melton, Emily Denise; Sorokin, Dimitry Y; Overmars, Lex; Chertkov, Olga; Clum, Alicia; Pillay, Manoj; Ivanova, Natalia; Shapiro, Nicole; Kyrpides, Nikos C; Woyke, Tanja; Lapidus, Alla L; Muyzer, Gerard

    2016-01-01

    Desulfurivibrio alkaliphilus strain AHT2(T) is a strictly anaerobic sulfidogenic haloalkaliphile isolated from a composite sediment sample of eight hypersaline alkaline lakes in the Wadi al Natrun valley in the Egyptian Libyan Desert. D. alkaliphilus AHT2(T) is Gram-negative and belongs to the family Desulfobulbaceae within the Deltaproteobacteria. Here we report its genome sequence, which contains a 3.10 Mbp chromosome. D. alkaliphilus AHT2(T) is adapted to survive under highly alkaline and moderately saline conditions and therefore, is relevant to the biotechnology industry and life under extreme conditions. For these reasons, D. alkaliphilus AHT2(T) was sequenced by the DOE Joint Genome Institute as part of the Community Science Program.

  7. Heterotrophic denitrification at extremely high salt and pH by haloalkaliphilic Gammaproteobacteria from hypersaline soda lakes

    PubMed Central

    Shapovalova, A. A.; Khijniak, T. V.; Tourova, T. P.; Muyzer, G.

    2008-01-01

    In this paper we describe denitrification at extremely high salt and pH in sediments from hypersaline alkaline soda lakes and soda soils. Experiments with sediment slurries demonstrated the presence of acetate-utilizing denitrifying populations active at in situ conditions. Anaerobic enrichment cultures at pH 10 and 4 M total Na+ with acetate as electron donor and nitrate, nitrite and N2O as electron acceptors resulted in the dominance of Gammaproteobacteria belonging to the genus Halomonas. Both mixed and pure culture studies identified nitrite and N2O reduction as rate-limiting steps in the denitrification process at extremely haloalkaline conditions. Electronic supplementary material The online version of this article (doi:10.1007/s00792-008-0166-6) contains supplementary material, which is available to authorized users. PMID:18452025

  8. Estimating Inland Ground Motions from Lake Turbidite Sequences, Northern Cascadia margin, USA.

    NASA Astrophysics Data System (ADS)

    Goldfinger, C.; Hausmann, R. B.; Black, B.; Romsos, C. G.; Beeson, J. W.; Galer, S.; Collins, T.

    2016-12-01

    Using cores collected from lakes in northern Oregon and Washington, we are attempting to estimate ground motions from plate boundary earthquakes at inland paleoseismic sites. Paleoseismic evidence in Cascadia comes largely from coastal and offshore sites, while population the main population centers of Seattle, Victoria, Vancouver and Portland are 100-180 km inland. Cores from Leland Lake on the Olympic Peninsula, Lake Sawyer, near Seattle, and Bull Run Lake, 65 km east of Portland contain sequences of event beds that are interpreted as internal lake turbidites. The number, timing based on 14C constrained age models, sequencing, and individual event characteristics correlated with physical properties and CT data are compatible with onshore and offshore paleoseismic records of plate boundary earthquakes. The likely correlative turbidite sequence at Bull Run is well-matched to the nearest offshore turbidite sequences at Hydrate Ridge and Oceanus Basin (see also Hausmann et al. this meeting). Similarly, the Washington lake sequences are well matched to the offshore Washington sequences (Goldfinger et al. 2016), with the likely inclusion of a single Seattle Fault earthquake 1000 cal BP. Bull Run Lake has several ashes, but otherwise, additional event beds related to crustal faulting or other events are not observed. Our strategy is to investigate lakes that have low sensitivity to subaquatic slope failures in order to explore the limits of stability. In this case, the minimum ground shaking required for slope failure will approach actual ground motions as stability increases. We mapped failure zones within the lakes, and collected shear vane measurements to estimate sediment cohesion. We then computed minimum ground motions for these sites. For Leland Lake, there are no mappable failures, indicating internal lake turbidites likely were generated by thin surface failures below mapping resolution. For Sawyer and Bull Run, the most stable failure sites require 0.2-0.3g

  9. Pyrosequencing analysis of bacterial communities in Lake Bosten, a large brackish inland lake in the arid northwest of China.

    PubMed

    Zhang, Lei; Gao, Guang; Tang, Xiangming; Shao, Keqiang; Gong, Yi

    2016-06-01

    The bacteria inhabiting brackish lake environments are poorly known, and there are few studies on the microbial diversity of these environments. Lake Bosten, a large brackish inland lake, is the largest lake in Xinjiang Province in northwestern China. Because sediments record past limnic changes, the analysis of sedimentary bacteria in Lake Bosten may help elucidate bacterial responses to environmental change. We employed 454 pyrosequencing to investigate the diversity and bacterial community composition in Lake Bosten. A total of 48 230 high-quality sequence reads with 16 314 operational taxonomic units were successfully obtained from the 4 selected samples, and they were numerically dominated by members of the Deltaproteobacteria (17.1%), Chloroflexi (16.1%), Betaproteobacteria (12.6%), Bacteroidetes (6.6%), and Firmicutes (5.7%) groups, accounting for more than 58.1% of the bacterial sequences. The sediment bacterial communities and diversity were consistently different along the 2 geographic environmental gradients: (i) freshwater-brackish water gradient and (ii) oligotrophic-mesotrophic habitat gradient. Deltaproteobacteria, Chloroflexi, and Betaproteobacteria were amplified throughout all of the sampling sites. More Bacteroidetes and Firmicutes were found near the Kaidu River estuary (site 14). Our investigation showed that Proteobacteria did not display any systematic change along the salinity gradient, and numerous 16S rRNA sequences could not be identified at the genus level. Our data will provide a better understanding of the diversity and distribution of bacteria in arid region brackish lakes.

  10. Desulfonatronobacter acetoxydans sp. nov.,: a first acetate-oxidizing, extremely salt-tolerant alkaliphilic SRB from a hypersaline soda lake.

    PubMed

    Sorokin, D Y; Chernyh, N A; Poroshina, M N

    2015-09-01

    Recent intensive microbiological investigation of sulfidogenesis in soda lakes did not result in isolation of any pure cultures of sulfate-reducing bacteria (SRB) able to directly oxidize acetate. The sulfate-dependent acetate oxidation at haloalkaline conditions has, so far, been only shown in two syntrophic associations of novel Syntrophobacteraceae members and haloalkaliphilic hydrogenotrophic SRB. In the course of investigation of one of them, obtained from a hypersaline soda lake in South-Western Siberia, a minor component was observed showing a close relation to Desulfonatronobacter acidivorans--a "complete oxidizing" SRB from soda lakes. This organism became dominant in a secondary enrichment with propionate as e-donor and sulfate as e-acceptor. A pure culture, strain APT3, was identified as a novel member of the family Desulfobacteraceae. It is an extremely salt-tolerant alkaliphile, growing with butyrate at salinity up to 4 M total Na(+) with a pH optimum at 9.5. It can grow with sulfate as e-acceptor with C3-C9 VFA and also with some alcohols. The most interesting property of strain APT3 is its ability to grow with acetate as e-donor, although not with sulfate, but with sulfite or thiosulfate as e-acceptors. The new isolate is proposed as a new species Desulfonatronobacter acetoxydans.

  11. Metagenome sequencing of the prokaryotic microbiota of the hypersaline and meromictic soap lake, washington.

    PubMed

    Hawley, Erik R; Hess, Matthias

    2014-01-23

    Soap Lake is a small saline lake in central eastern Washington that is sharply stratified into two layers. In addition to being highly alkaline (~pH 10), Soap Lake also contains high concentrations of sulfide. Here, we report the community profile of the prokaryotic microbiota associated with Soap Lake surface water.

  12. Water-quality characteristics of Michigan's inland lakes, 2001-10

    USGS Publications Warehouse

    Fuller, L.M.; Taricska, C.K.

    2012-01-01

    The U.S. Geological Survey and the Michigan Department of Environmental Quality (MDEQ) jointly monitored for selected water-quality constituents and properties of inland lakes during 2001–10 as part of Michigan's Lake Water-Quality Assessment program. During 2001–10, 866 lake basins from 729 inland lakes greater than 25 acres were monitored for baseline water-quality conditions and trophic status. This report summarizes the water-quality characteristics and trophic conditions of the monitored lakes throughout the State; the data include vertical-profile measurements, nutrient measurements at three discrete depths, Secchi-disk transparency (SDT) measurements, and chlorophyll a measurements for the spring and summer, with major ions and other chemical indicators measured during the spring at mid-depth and color during the summer from near-surface samples. In about 75 percent of inland lake deep basins (index stations), trophic characteristics were associated with oligotrophic or mesotrophic conditions; 5 percent or less were categorized as hypereutrophic, and 80 percent of hypereutrophic lakes had a maximum depth of 30 feet or less. Comparison of spring and summer measurements shows that water clarity based on SDT measurements were clearer in the spring than in the summer for 63 percent of lakes. For near-surface measurements made in spring, 97 percent of lakes can be considered phosphorus limited and less than half a percent nitrogen limited; for summer measurements, 96 percent of lakes can be considered phosphorus limited and less than half a percent nitrogen limited. Spatial patterns of major ions, alkalinity, and hardness measured in the spring at mid-depth all showed lower values in the Upper Peninsula of Michigan and a southward increase toward the southern areas of the Lower Peninsula, though the location of increase varied by constituent. A spatial analysis of the data based on U.S. Environmental Protection Agency Level III Ecoregions separated potassium

  13. Reconstruction of atmospheric soot history in inland regions from lake sediments over the past 150 years

    PubMed Central

    Han, Y. M.; Wei, C.; Huang, R.-J.; Bandowe, B. A. M.; Ho, S. S. H.; Cao, J. J.; Jin, Z. D.; Xu, B. Q.; Gao, S. P.; Tie, X. X.; An, Z. S.; Wilcke, W.

    2016-01-01

    Historical reconstruction of atmospheric black carbon (BC, in the form of char and soot) is still constrained for inland areas. Here we determined and compared the past 150-yr records of BC and polycyclic aromatic compounds (PACs) in sediments from two representative lakes, Huguangyan (HGY) and Chaohu (CH), in eastern China. HGY only receives atmospheric deposition while CH is influenced by riverine input. BC, char, and soot have similar vertical concentration profiles as PACs in both lakes. Abrupt increases in concentrations and mass accumulation rates (MARs) of soot have mainly occurred since ~1950, the establishment of the People’s Republic of China, when energy usage changed to more fossil fuel contributions reflected by the variations in the concentration ratios of char/soot and individual PACs. In HGY, soot MARs increased by ~7.7 times in the period 1980–2012 relative to the period 1850–1950. Similar increases (~6.7 times) were observed in CH. The increase in soot MARs is also in line with the emission inventory records in the literature and the fact that the submicrometer-sized soot particles can be dispersed regionally. The study provides an alternative method to reconstruct the atmospheric soot history in populated inland areas. PMID:26750586

  14. Comparing rapid and culture indicator bacteria methods at inland lake beaches

    USGS Publications Warehouse

    Francy, Donna S.; Bushon, Rebecca N.; Brady, Amie M.G.; Kephart, Christopher M.

    2013-01-01

    A rapid method, quantitative polymerase chain reaction (qPCR), for quantifying indicator bacteria in recreational waters is desirable for public health protection. We report that replacing current Escherichia coli standards with new US Environmental Protection Agency beach action values (BAVs) for enterococci by culture or qPCR may result in more advisories being posted at inland recreational lakes. In this study, concentrations of E. coli and enterococci by culture methods were compared to concentrations of Enterococcus spp. by qPCR at 3 inland lake beaches in Ohio. The E. coli and enterococci culture results were significantly related at all beaches; however, the relations between culture results and Enterococcus spp. qPCR results were not always significant and differed among beaches. All the qPCR results exceeded the new BAV for Enterococcus spp. by qPCR, whereas only 23.7% of culture results for E. coli and 79% of culture results for enterococci exceeded the current standard for E. coli or BAV for enterococci.

  15. Reconstruction of atmospheric soot history in inland regions from lake sediments over the past 150 years

    NASA Astrophysics Data System (ADS)

    Han, Y. M.; Wei, C.; Huang, R.-J.; Bandowe, B. A. M.; Ho, S. S. H.; Cao, J. J.; Jin, Z. D.; Xu, B. Q.; Gao, S. P.; Tie, X. X.; An, Z. S.; Wilcke, W.

    2016-01-01

    Historical reconstruction of atmospheric black carbon (BC, in the form of char and soot) is still constrained for inland areas. Here we determined and compared the past 150-yr records of BC and polycyclic aromatic compounds (PACs) in sediments from two representative lakes, Huguangyan (HGY) and Chaohu (CH), in eastern China. HGY only receives atmospheric deposition while CH is influenced by riverine input. BC, char, and soot have similar vertical concentration profiles as PACs in both lakes. Abrupt increases in concentrations and mass accumulation rates (MARs) of soot have mainly occurred since ~1950, the establishment of the People’s Republic of China, when energy usage changed to more fossil fuel contributions reflected by the variations in the concentration ratios of char/soot and individual PACs. In HGY, soot MARs increased by ~7.7 times in the period 1980–2012 relative to the period 1850–1950. Similar increases (~6.7 times) were observed in CH. The increase in soot MARs is also in line with the emission inventory records in the literature and the fact that the submicrometer-sized soot particles can be dispersed regionally. The study provides an alternative method to reconstruct the atmospheric soot history in populated inland areas.

  16. 46 CFR 11.437 - Service requirements for mate of Great Lakes and inland steam or motor vessels of any gross tons.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... steam or motor vessels of any gross tons. 11.437 Section 11.437 Shipping COAST GUARD, DEPARTMENT OF... Requirements for Deck Officers § 11.437 Service requirements for mate of Great Lakes and inland steam or motor... mate of Great Lakes and inland steam or motor vessels of any gross tons is: (1) Three years of...

  17. 46 CFR 11.437 - Service requirements for mate of Great Lakes and inland steam or motor vessels of any gross tons.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... steam or motor vessels of any gross tons. 11.437 Section 11.437 Shipping COAST GUARD, DEPARTMENT OF... Requirements for Deck Officers § 11.437 Service requirements for mate of Great Lakes and inland steam or motor... mate of Great Lakes and inland steam or motor vessels of any gross tons is: (1) Three years of...

  18. 46 CFR 11.437 - Service requirements for mate of Great Lakes and inland steam or motor vessels of any gross tons.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... steam or motor vessels of any gross tons. 11.437 Section 11.437 Shipping COAST GUARD, DEPARTMENT OF... Requirements for Deck Officers § 11.437 Service requirements for mate of Great Lakes and inland steam or motor... mate of Great Lakes and inland steam or motor vessels of any gross tons is: (1) Three years of...

  19. 46 CFR 11.437 - Service requirements for mate of Great Lakes and inland steam or motor vessels of any gross tons.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... steam or motor vessels of any gross tons. 11.437 Section 11.437 Shipping COAST GUARD, DEPARTMENT OF... Requirements for Deck Officers § 11.437 Service requirements for mate of Great Lakes and inland steam or motor... mate of Great Lakes and inland steam or motor vessels of any gross tons is: (1) Three years of...

  20. 46 CFR 11.456 - Service requirements for limited master of Great Lakes and inland steam or motor vessels of not...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Service requirements for limited master of Great Lakes and inland steam or motor vessels of not more than 100 gross tons. 11.456 Section 11.456 Shipping... master of Great Lakes and inland steam or motor vessels of not more than 100 gross tons. Limited...

  1. 46 CFR 11.456 - Service requirements for limited master of Great Lakes and inland steam or motor vessels of not...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Service requirements for limited master of Great Lakes and inland steam or motor vessels of not more than 100 gross tons. 11.456 Section 11.456 Shipping... master of Great Lakes and inland steam or motor vessels of not more than 100 gross tons. Limited...

  2. 46 CFR 11.456 - Service requirements for limited master of Great Lakes and inland steam or motor vessels of not...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Service requirements for limited master of Great Lakes and inland steam or motor vessels of not more than 100 gross tons. 11.456 Section 11.456 Shipping... master of Great Lakes and inland steam or motor vessels of not more than 100 gross tons. Limited...

  3. 46 CFR 11.456 - Service requirements for limited master of Great Lakes and inland steam or motor vessels of not...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Service requirements for limited master of Great Lakes and inland steam or motor vessels of not more than 100 gross tons. 11.456 Section 11.456 Shipping... master of Great Lakes and inland steam or motor vessels of not more than 100 gross tons. Limited...

  4. Controls on the pH of hyper-saline lakes - A lesson from the Dead Sea

    NASA Astrophysics Data System (ADS)

    Golan, Rotem; Gavrieli, Ittai; Ganor, Jiwchar; Lazar, Boaz

    2016-01-01

    high ionic strength (TDS = 348 g/L) and the dominance of the divalent cation, Mg2+. Other natural hyper-saline brines with high concentration of divalent cations such as Kunteyi Lake in China and Don-Juan Pond in Antarctica follow the same general pattern. In contrast, the high pH of soda lakes results not only from their high TA but also by the dominance of the monovalent cation, Na+. Our study emphasizes the strong control of brine composition on pKB‧ and pH. These factors should be taken into consideration when reconstructing past and present environmental evaporitic environments.

  5. Predicting lake trophic state by relating Secchi-disk transparency measurements to Landsat-satellite imagery for Michigan inland lakes, 2003-05 and 2007-08

    USGS Publications Warehouse

    Fuller, L.M.; Jodoin, R.S.; Minnerick, R.J.

    2011-01-01

    Inland lakes are an important economic and environmental resource for Michigan. The U.S. Geological Survey and the Michigan Department of Natural Resources and Environment have been cooperatively monitoring the quality of selected lakes in Michigan through the Lake Water Quality Assessment program. Sampling for this program began in 2001; by 2010, 730 of Michigan’s 11,000 inland lakes are expected to have been sampled once. Volunteers coordinated by the Michigan Department of Natural Resources and Environment began sampling lakes in 1974 and continue to sample (in 2010) approximately 250 inland lakes each year through the Michigan Cooperative Lakes Monitoring Program. Despite these sampling efforts, it still is impossible to physically collect measurements for all Michigan inland lakes; however, Landsat-satellite imagery has been used successfully in Minnesota, Wisconsin, Michigan, and elsewhere to predict the trophic state of unsampled inland lakes greater than 20 acres by producing regression equations relating in-place Secchi-disk measurements to Landsat bands. This study tested three alternatives to methods previously used in Michigan to improve results for predicted statewide Trophic State Index (TSI) computed from Secchi-disk transparency (TSI (SDT)). The alternative methods were used on 14 Landsat-satellite scenes with statewide TSI (SDT) for two time periods (2003– 05 and 2007–08). Specifically, the methods were (1) satellitedata processing techniques to remove areas affected by clouds, cloud shadows, haze, shoreline, and dense vegetation for inland lakes greater than 20 acres in Michigan; (2) comparison of the previous method for producing a single open-water predicted TSI (SDT) value (which was based on an area of interest (AOI) and lake-average approach) to an alternative Gethist method for identifying open-water areas in inland lakes (which follows the initial satellite-data processing and targets the darkest pixels, representing the deepest water

  6. Impacts of salinity parameterizations on temperature simulation over and in a hypersaline lake

    NASA Astrophysics Data System (ADS)

    Wen, Lijuan; Nagabhatla, Nidhi; Zhao, Lin; Li, Zhaoguo; Chen, Shiqiang

    2015-05-01

    In this paper, we introduced parameterizations of the salinity effects (on heat capacity, thermal conductivity, freezing point and saturated vapor pressure) in a lake scheme integrated in the Weather Research and Forecasting model coupled with the Community Land Model (WRF-CLM). This was done to improve temperature simulation over and in a saline lake and to test the contributions of salinity effects on various water properties via sensitivity experiments. The modified lake scheme consists of the lake module in the CLM model, which is the land component of the WRF-CLM model. The Great Salt Lake (GSL) in the USA was selected as the study area. The simulation was performed from September 3, 2001 to September 30, 2002. Our results show that the modified WRF-CLM model that includes the lake scheme considering salinity effects can reasonably simulate temperature over and in the GSL. This model had much greater accuracy than neglecting salinity effects, particularly in a very cold event when that effect alters the freezing point. The salinity effect on saturated vapor pressure can reduce latent heat flux over the lake and make it slightly warmer. The salinity effect on heat capacity can also make lake temperature prone to changes. However, the salinity effect on thermal conductivity was found insignificant in our simulations.

  7. Changes in the area of inland lakes in arid regions of central Asia during the past 30 years.

    PubMed

    Bai, Jie; Chen, Xi; Li, Junli; Yang, Liao; Fang, Hui

    2011-07-01

    Inland lakes are major surface water resource in arid regions of Central Asia. The area changes in these lakes have been proved to be the results of regional climate changes and recent human activities. This study aimed at investigating the area variations of the nine major lakes in Central Asia over the last 30 years. Firstly, multi-temporal Landsat imagery in 1975, 1990, 1999, and 2007 were used to delineate lake extents automatically based on Normalized Difference Water Index (NDWI) threshold segmentation, then lake area variations were detailed in three decades and the mechanism of these changes was analyzed with meteorological data and hydrological data. The results indicated that the total surface areas of these nine lakes had decreased from 91,402.06 km(2) to 46,049.23 km(2) during 1975-2007, accounting for 49.62% of their original area of 1975. Tail-end lakes in flat areas had shrunk dramatically as they were induced by both climate changes and human impacts, while alpine lakes remained relatively stable due to the small precipitation variations. With different water usage of river outlets, the variations of open lakes were more flexible than those of other two types. According to comprehensive analyses, different types of inland lakes presented different trends of area changes under the background of global warming effects in Central Asia, which showed that the increased human activities had broken the balance of water cycles in this region.

  8. Bacillus locisalis sp. nov., a new haloalkaliphilic species from hypersaline and alkaline lakes of China, Kenya and Tanzania.

    PubMed

    Márquez, M Carmen; Carrasco, Inmaculada J; de la Haba, Rafael R; Jones, Brian E; Grant, William D; Ventosa, Antonio

    2011-09-01

    A polyphasic taxonomic study was performed on seven Bacillus-like bacteria isolated from three hypersaline and alkaline lakes located in China, Kenya and Tanzania. All strains were moderately halophilic and alkaliphilic, Gram positive, motile rods. The DNA G+C content from the seven isolates ranged from 42.2 to 43.4mol% and their major fatty acid was anteiso-C(15:0). Strain CG1(T), selected as representative strain of the isolates, possesses meso-diaminopimelic acid in the cell wall peptidoglycan, MK-7 as the predominant menaquinone and diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine as the major polar lipids. Comparative 16S rRNA gene sequence analysis indicated that the isolates belonged to the genus Bacillus. The seven isolates shared 97.7-99.9% 16S rRNA gene sequence similarity, and formed a branch that was distinct from the type strains of the recognized species of the genus Bacillus. They were most closely related to Bacillus agaradhaerens DSM 8721(T) (92.6-93.8% 16S rRNA sequence similarity). DNA-DNA hybridization values between the seven isolates were 85-100%. According to the polyphasic characterization, the strains represent a novel species, for which the name Bacillus locisalis sp. nov. is proposed. The type strain is CG1(T) (CCM 7370(T)=CECT 7152(T)=CGMCC 1.6286(T)=DSM 18085(T)). Copyright © 2011 Elsevier GmbH. All rights reserved.

  9. Natronospira proteinivora gen. nov., sp. nov, an extremely salt-tolerant, alkaliphilic gammaproteobacterium from hypersaline soda lakes.

    PubMed

    Sorokin, Dimitry Y; Kublanov, Ilya V; Khijniak, Tatiana V

    2017-08-01

    Brine samples from Kulunda Steppe soda lakes (Altai, Russia) were inoculated into a hypersaline alkaline mineral medium with β-keratin (chicken feather) as a substrate. The micro-organisms dominating the enrichment culture were isolated by limiting serial dilution on the same medium with casein as a substrate. The cells of strain BSker1T were motile, curved rods. The strain was an obligately aerobic heterotroph utilizing proteins and peptides as growth substrates. The isolate was an obligate alkaliphile with a pH range for growth from pH 8.5 to 10.25 (optimum at pH 9.5), and it was extremely salt tolerant, growing with between 1 and 4.5 M total Na+ (optimally at 2-2.5 M). BSker1T had a unique composition of polar lipid fatty acids, dominated by two C17 species. The membrane polar lipids included multiple unidentified phospholipids and two aminolipids. According to phylogenetic analysis of the 16S rRNA gene sequence, the isolate forms a novel branch within the family Ectothiorhodospiraceae (class Gammaproteobacteria) with the highest sequence similarity to the members of this family being 91 %. On the basis of distinct phenotypic and genotypic properties, strain BSker1T (=JCM 31341T=UNIQEM U1008T) is proposed to be classified as a representative of a novel genus and species, Natronospira proteinivora gen. nov., sp. nov.

  10. Characterization of thermo-solvent stable protease from Halobacillus sp. CJ4 isolated from Chott Eldjerid hypersaline lake in Tunisia.

    PubMed

    Daoud, Lobna; Jlidi, Mouna; Hmani, Houda; Hadj Brahim, Adel; El Arbi, Mahdi; Ben Ali, Mamdouh

    2017-02-01

    About 110 newly isolated halophilic and halotolerant bacteria were screened for protease production. A moderately halophilic strain (CJ4), isolated from Chott Eldjerid Hypersaline lake in Tunisia, showed the highest activity on agar plate and was then selected. The biochemical and physiological characterization of the isolate along with the 16S rRNA sequence analysis placed it in the genus Halobacillus. Protease production was maximal at 120 g/L NaCl (2 M) and it started from the post-exponential phase reaching a maximum level at the early decline phase of bacterial growth. Protease activity was optimal at 0.4 M NaCl, pH 9 and 45 °C. It showed an excellent stability over wide ranges of temperatures (30-60 °C), NaCl concentrations (0-5 M), and pH values (5-10), which make it a good candidate for industrial applications at harsh conditions. Crude protease was strongly inhibited by PMSF revealing the dominance of serine proteases. Protease activity exhibited high stability in the presence of several organic solvents and detergent additives. These findings make Halobacillus sp. CJ4 protease with a great interest for many biotechnological applications at high salt or low water content such as peptide synthesis and detergent formulation.

  11. Predicting water quality by relating secchi-disk transparency and chlorophyll a measurements to Landsat satellite imagery for Michigan inland lakes, 2001-2006

    USGS Publications Warehouse

    Fuller, L.M.; Minnerick, R.J.

    2007-01-01

    The State of Michigan has more than 11,000 inland lakes; approximately 3,500 of these lakes are greater than 25 acres. The USGS, in cooperation with the Michigan Department of Environmental Quality (MDEQ), has been monitoring the quality of inland lakes in Michigan through the Lake Water Quality Assessment monitoring program. Approximately 100 inland lakes will be sampled per year from 2001 to 2015. Volunteers coordinated by MDEQ started sampling lakes in 1974, and continue to sample to date approximately 250 inland lakes each year through the Cooperative Lakes Monitoring Program (CLMP), Michigan’s volunteer lakes monitoring program. Despite this sampling effort, it is still impossible to physically collect the necessary water-quality measurements for all 3,500 Michigan inland lakes. Therefore, a technique was used by USGS, modeled after Olmanson and others (2001), in cooperation with MDEQ that uses satellite remote sensing to predict water quality in unsampled inland lakes greater than 25 acres. Water-quality characteristics that are associated with water clarity can be predicted for Michigan inland lakes by relating sampled measurements of secchi-disk transparency (SDT) and chlorophyll a concentrations (Chl-a), to satellite imagery. The trophic state index (TSI) which is an indicator of the biological productivity can be calculated based on SDT measurements, Chl-a concentrations, and total phosphorus (TP) concentrations measured near the lake’s surface. Through this process, unsampled inland lakes within the fourteen Landsat satellite scenes encompassing Michigan can be translated into estimated TSI from either predicted SDT or Chl-a (fig. 1).

  12. 46 CFR 11.431 - Tonnage requirements for Great Lakes and inland endorsements for vessels of over 1600 gross tons.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... must be obtained on vessels of 1600 gross tons or over. (b) Tonnage limitations may be imposed on these... endorsements for vessels of over 1600 gross tons. 11.431 Section 11.431 Shipping COAST GUARD, DEPARTMENT OF... vessels of over 1600 gross tons. (a) All required experience for Great Lakes and inland unlimited...

  13. Dissimilatory arsenate and sulfate reduction in sediments of two hypersaline, arsenic-rich soda lakes: Mono and Searles Lakes, California

    USGS Publications Warehouse

    Kulp, T.R.; Hoeft, S.E.; Miller, L.G.; Saltikov, C.; Murphy, J.N.; Han, S.; Lanoil, B.; Oremland, R.S.

    2006-01-01

    A radioisotope method was devised to study bacterial respiratory reduction of arsenate in sediments. The following two arsenic-rich soda lakes in California were chosen for comparison on the basis of their different salinities: Mono Lake (???90 g/liter) and Searles Lake (???340 g/liter). Profiles of arsenate reduction and sulfate reduction were constructed for both lakes. Reduction of [73As] arsenate occurred at all depth intervals in the cores from Mono Lake (rate constant [k] = 0.103 to 0.04 h-1) and Searles Lake (k = 0.012 to 0.002 h-1), and the highest activities occurred in the top sections of each core. In contrast, [35S] sulfate reduction was measurable in Mono Lake (k = 7.6 ?? 104 to 3.2 ?? 10-6 h-1) but not in Searles Lake. Sediment DNA was extracted, PCR amplified, and separated by denaturing gradient gel electrophoresis (DGGE) to obtain phylogenetic markers (i.e., 16S rRNA genes) and a partial functional gene for dissimilatory arsenate reduction (arrA). The amplified arrA gene product showed a similar trend in both lakes; the signal was strongest in surface sediments and decreased to undetectable levels deeper in the sediments. More arrA gene signal was observed in Mono Lake and was detectable at a greater depth, despite the higher arsenate reduction activity observed in Searles Lake. A partial sequence (about 900 bp) was obtained for a clone (SLAS-3) that matched the dominant DGGE band found in deeper parts of the Searles Lake sample (below 3 cm), and this clone was found to be closely related to SLAS-1, a novel extremophilic arsenate respirer previously cultivated from Searles Lake. Copyright ?? 2006, American Society for Microbiology. All Rights Reserved.

  14. Dissimilatory arsenate and sulfate reduction in sediments of two hypersaline, arsenic-rich soda lakes: Mono and Searles Lakes, California.

    PubMed

    Kulp, T R; Hoeft, S E; Miller, L G; Saltikov, C; Murphy, J N; Han, S; Lanoil, B; Oremland, R S

    2006-10-01

    A radioisotope method was devised to study bacterial respiratory reduction of arsenate in sediments. The following two arsenic-rich soda lakes in California were chosen for comparison on the basis of their different salinities: Mono Lake (approximately 90 g/liter) and Searles Lake (approximately 340 g/liter). Profiles of arsenate reduction and sulfate reduction were constructed for both lakes. Reduction of [73As]arsenate occurred at all depth intervals in the cores from Mono Lake (rate constant [k] = 0.103 to 0.04 h(-1)) and Searles Lake (k = 0.012 to 0.002 h(-1)), and the highest activities occurred in the top sections of each core. In contrast, [35S]sulfate reduction was measurable in Mono Lake (k = 7.6 x10(4) to 3.2 x 10(-6) h(-1)) but not in Searles Lake. Sediment DNA was extracted, PCR amplified, and separated by denaturing gradient gel electrophoresis (DGGE) to obtain phylogenetic markers (i.e., 16S rRNA genes) and a partial functional gene for dissimilatory arsenate reduction (arrA). The amplified arrA gene product showed a similar trend in both lakes; the signal was strongest in surface sediments and decreased to undetectable levels deeper in the sediments. More arrA gene signal was observed in Mono Lake and was detectable at a greater depth, despite the higher arsenate reduction activity observed in Searles Lake. A partial sequence (about 900 bp) was obtained for a clone (SLAS-3) that matched the dominant DGGE band found in deeper parts of the Searles Lake sample (below 3 cm), and this clone was found to be closely related to SLAS-1, a novel extremophilic arsenate respirer previously cultivated from Searles Lake.

  15. The influence of salinity on D/H fractionation in dinosterol and brassicasterol from globally distributed saline and hypersaline lakes

    NASA Astrophysics Data System (ADS)

    Nelson, Daniel B.; Sachs, Julian P.

    2014-05-01

    Salinity, growth rate, growth stage, nutrient limitation and temperature have all been shown to influence the magnitude of D/H fractionation in algal lipids through laboratory and field studies. Of these factors, salinity has been studied most extensively in the field, but to date all such investigations have focused on transect studies within specific and isolated environments. Here we test the relationship between salinity and the magnitude of D/H fractionation in algal lipids through paired analyses of sedimentary and particulate lipid and water hydrogen isotope values at a wide range of continental and coastal lake sites spanning salinities from 0 to 117 ppt. Our results demonstrate broad consistency between D/H fractionations in dinosterol and brassicasterol with those obtained from previous work, with salinity changes of 1 ppt resulting in lipid δD changes of 0.7-1‰. Although our results also show variability in D/H fractionation between sites that is not related to salinity, the fact that any relationship emerges above the influences of other factors suggests that the salinity effect is dominant for some lipids in the majority of saline to hypersaline environments. This improved understanding of D/H fractionation in dinosterol and brassicasterol synthesis supports the use of these compounds as paleohydrologic indicators. When combined with D/H measurements from a second lipid or oxygen isotope measurements from carbonate, quantitative reconstructions of salinity and lake water isotope changes are possible. Extending the number of algal lipids within which a consistent relationship between D/H fractionation and salinity has been identified also supports the notion that the relationship is widespread among unicellular photoautotrophs.

  16. First survey of fungi in hypersaline soil and water of Mono Lake area (California).

    PubMed

    Steiman, Régine; Ford, Larry; Ducros, Véronique; Lafond, Jean-Luc; Guiraud, Pascale

    2004-01-01

    Mono Lake is a closed lake located in central California, east of the Sierra Nevada mountains. It contains dissolved carbonates, sulfates and chlorides at high concentrations. Due to its high salinity, Mono Lake was sometimes compared to the Dead Sea. However, it appears that Mono Lake water and vicinity abound with life. In this work, the fungal flora living in this extreme ecosystem was studied for the first time. Soil, tufa, water and sediment samples were also analyzed for their mineral and salt composition. Results showed that water was particularly rich in sodium, potassium, phosphorus and boron. Soil and sediments contained very high levels of calcium and magnesium, but also barium, boron and strontium. Sodium, phosphorus and iron levels varied in a large extent from one to another sample. Neutral to very alkaline pH were recorded. Water samples were found sterile in the conditions chosen for fungi isolation, while sediment, soil and tufa samples led to the isolation of a total of 67 fungal species (from 23 samples), belonging to various taxonomic groups. From our results no clear effects of the chemical parameters of the samples were observed on fungal life apart from the pH. The methods chosen did not allow the isolation of extremely halotolerant species. We isolated in this work a series of ubiquitous species, suggesting that a selection of resistant and/or adaptable strains of some common species could have occurred. Depending on the medium and the temperature of isolation, it can be hypothesized that some species were present as dormant structures, while some others, isolated at pH 8 on a medium enriched in Na and Ca, could be in a growing form adapted to alkaline and saline conditions. This work contributes to a better knowledge of the mycobiota present in the Mono Lake's ecosystem.

  17. Methylohalomonas lacus gen. nov., sp. nov. and Methylonatrum kenyense gen. nov., sp. nov., methylotrophic gammaproteobacteria from hypersaline lakes.

    PubMed

    Sorokin, Dimitry Yu; Trotsenko, Yuri A; Doronina, Nina V; Tourova, Tatjana P; Galinski, Erwin A; Kolganova, Tatjana V; Muyzer, Gerard

    2007-12-01

    Aerobic enrichment at 4 M NaCl, pH 7.5, with methanol as carbon and energy source from sediments of hypersaline chloride-sulfate lakes in Kulunda Steppe (Altai, Russia) resulted in the isolation of a moderately halophilic and obligately methylotrophic bacterium, strain HMT 1(T). The bacterium grew with methanol and methylamine within a pH range of 6.8-8.2 with an optimum at pH 7.5 and at NaCl concentrations of 0.5-4 M with an optimum at 2 M. In addition to methanol and methylamine, it can oxidize ethanol, formate, formaldehyde and dimethylamine. Carbon is assimilated via the serine pathway. The main compatible solute is glycine betaine. 16S rRNA gene sequence analysis placed the isolate as a new lineage in the family Ectothiorhodospiraceae (Gammaproteobacteria). It is proposed, therefore, to accommodate this bacterium within a novel genus and species, Methylohalomonas lacus gen. nov., sp. nov., with HMT 1(T) (=DSM 15733(T) =NCCB 100208(T) =UNIQEM U237(T)) as the type strain. Two strains were obtained in pure culture from sediments of soda lake Magadi in Kenya and the Kulunda Steppe (Russia) on a mineral medium at pH 10 containing 0.6 M total Na(+) using methanol as a substrate. Strain AMT 1(T) was enriched with methanol, while strain AMT 3 originated from an enrichment culture with CO. The isolates are restricted facultative methylotrophs, capable of growth with methanol, formate and acetate as carbon and energy sources. With methanol, the strains grew within a broad salinity range from 0.3 to 3.5-4 M total Na(+), with an optimum at 0.5-1 M. The pH range for growth was between 8.3 and 10.5, with an optimum at pH 9.5, which characterized the soda lake isolates as obligate haloalkaliphiles. Carbon is assimilated autotrophically via the Calvin-Benson cycle. Sequence analysis of the gene coding for the key enzyme RuBisCO demonstrated that strain AMT 1(T) possessed a single cbbL gene of the 'green' form I, clustering with members of the family Ectothiorhodospiraceae

  18. Growth-dependent hydrogen isotopic fractionation of algal lipid biomarkers in hypersaline Isabel Lake (México)

    NASA Astrophysics Data System (ADS)

    Romero-Viana, Lidia; Kienel, Ulrike; Wilkes, Heinz; Sachse, Dirk

    2013-04-01

    In this study, we evaluated the potential of the hydrogen isotopic composition of algal lipid biomarkers as a proxy for past hydroclimatic variability in hypersaline Isabel Lake, Mexico (Eastern Pacific). We compared rainfall variability recorded in the region over the last 65 years with changes in δD values of the most abundant compounds preserved in the uppermost 16 cm of lake sediment. Changes in δD values of the 1,15-C32 diol (δDdiol), a specific biomarker of algal populations, were related to rainfall variability; specifically, n-alkyl diols were more deuterium-enriched (depleted) during wetter (drier) periods. Strikingly, neither the magnitude of lipid biomarker isotopic changes over interannual timescales (of up to 70-80‰) nor the direction of that variability can be explained by changes in δD values of the water source or salinity fluctuations (approximately 30 on the practical salinity scale) controlled by seasonal rainfall. However, changes in sedimentary biomarker composition, higher total organic carbon content and less negative δ13C values of the 1,15-C32 diol indicate enhanced algal growth during wetter periods. We find that these conditions result in less negative δD values of n-alkyl diols. We hypothesize that due to higher lipid demand during enhanced algal growth, an increasing proportion of hydrogen for lipid synthesis is derived from the cytosol via oxidation of polysaccharides, which may cause a deuterium enrichment of the acetogenic compounds. This study has significant implications for paleohydrological reconstructions using algal lipid δD values, particularly in highly seasonal environments such as Isabel Lake. In such environments, δD values of specific algal lipid biomarkers may not record the full seasonal cycle in source water δD but appear to be mainly controlled by the physiological state of algal populations. Our data provide the first evidence that changes in D/H fractionation due to algal growth conditions can be recorded

  19. Prokaryotic diversity in Aran-Bidgol salt lake, the largest hypersaline playa in Iran.

    PubMed

    Makhdoumi-Kakhki, Ali; Amoozegar, Mohammad Ali; Kazemi, Bahram; Pašić, Lejla; Ventosa, Antonio

    2012-01-01

    Prokaryotic diversity in Aran-Bidgol salt lake, a thalasohaline lake in Iran, was studied by fluorescence in situ hybridization (FISH), cultivation techniques, denaturing gradient gel electrophoresis (DGGE) of PCR-amplified fragments of 16S rRNA genes and 16S rRNA gene clone library analysis. Viable counts obtained (2.5-4 × 10(6) cells mL(-1)) were similar to total cell abundance in the lake determined by DAPI direct count (3-4×10(7) cells mL(-1)). The proportion of Bacteria to Archaea in the community detectable by FISH was unexpectedly high and ranged between 1:3 and 1:2. We analyzed 101 archaeal isolates and found that most belonged to the genera Halorubrum (55%) and Haloarcula (18%). Eleven bacterial isolates obtained in pure culture were affiliated with the genera Salinibacter (18.7%), Salicola (18.7%) and Rhodovibrio (35.3%). Analysis of inserts of 100 clones from the eight 16S rRNA clone libraries constructed revealed 37 OTUs. The majority (63%) of these sequences were not related to any previously identified taxa. Within this sampling effort we most frequently retrieved phylotypes related to Halorhabdus (16% of archaeal sequences obtained) and Salinibacter (36% of bacterial sequences obtained). Other prokaryotic groups that were abundant included representatives of Haloquadratum, the anaerobic genera Halanaerobium and Halocella, purple sulfur bacteria of the genus Halorhodospira and Cyanobacteria.

  20. 46 CFR 11.433 - Service requirements for master of Great Lakes and inland steam or motor vessels of any gross tons.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... inland steam or motor vessels of any gross tons. 11.433 Section 11.433 Shipping COAST GUARD, DEPARTMENT... steam or motor vessels of any gross tons. The minimum service required to qualify an applicant for an endorsement as master of Great Lakes and inland steam or motor vessels of any gross tons is: (a) One year...

  1. 46 CFR 11.446 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... inland steam or motor vessels of not more than 500 gross tons. 11.446 Section 11.446 Shipping COAST GUARD... steam or motor vessels of not more than 500 gross tons. The minimum service required to qualify an applicant for an endorsement as master of Great Lakes and inland steam or motor vessels of not more than...

  2. 46 CFR 11.446 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... inland steam or motor vessels of not more than 500 gross tons. 11.446 Section 11.446 Shipping COAST GUARD... steam or motor vessels of not more than 500 gross tons. The minimum service required to qualify an applicant for an endorsement as master of Great Lakes and inland steam or motor vessels of not more than...

  3. 46 CFR 11.433 - Service requirements for master of Great Lakes and inland steam or motor vessels of any gross tons.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... inland steam or motor vessels of any gross tons. 11.433 Section 11.433 Shipping COAST GUARD, DEPARTMENT... steam or motor vessels of any gross tons. The minimum service required to qualify an applicant for an endorsement as master of Great Lakes and inland steam or motor vessels of any gross tons is: (a) One year...

  4. 46 CFR 11.446 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... inland steam or motor vessels of not more than 500 gross tons. 11.446 Section 11.446 Shipping COAST GUARD... steam or motor vessels of not more than 500 gross tons. The minimum service required to qualify an applicant for an endorsement as master of Great Lakes and inland steam or motor vessels of not more than...

  5. 46 CFR 11.442 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... inland steam or motor vessels of not more than 1600 gross tons. 11.442 Section 11.442 Shipping COAST... Lakes and inland steam or motor vessels of not more than 1600 gross tons. The minimum service required... of not more than 1600 gross tons is: (a) Three years total service on vessels. Eighteen months of the...

  6. An Equation of State for Hypersaline Water in Great Salt Lake, Utah, USA

    USGS Publications Warehouse

    Naftz, D.L.; Millero, F.J.; Jones, B.F.; Green, W.R.

    2011-01-01

    Great Salt Lake (GSL) is one of the largest and most saline lakes in the world. In order to accurately model limnological processes in GSL, hydrodynamic calculations require the precise estimation of water density (??) under a variety of environmental conditions. An equation of state was developed with water samples collected from GSL to estimate density as a function of salinity and water temperature. The ?? of water samples from the south arm of GSL was measured as a function of temperature ranging from 278 to 323 degrees Kelvin (oK) and conductivity salinities ranging from 23 to 182 g L-1 using an Anton Paar density meter. These results have been used to develop the following equation of state for GSL (?? = ?? 0.32 kg m-3): ?? - ??0 = 184.01062 + 1.04708 * S - 1.21061*T + 3.14721E - 4*S2 + 0.00199T2 where ??0 is the density of pure water in kg m-3, S is conductivity salinity g L-1, and T is water temperature in degrees Kelvin. ?? 2011 U.S. Government.

  7. Discovery of anaerobic lithoheterotrophic haloarchaea, ubiquitous in hypersaline habitats.

    PubMed

    Sorokin, Dimitry Y; Messina, Enzo; Smedile, Francesco; Roman, Pawel; Damsté, Jaap S Sinninghe; Ciordia, Sergio; Mena, Maria Carmen; Ferrer, Manuel; Golyshin, Peter N; Kublanov, Ilya V; Samarov, Nazar I; Toshchakov, Stepan V; La Cono, Violetta; Yakimov, Michail M

    2017-05-01

    Hypersaline anoxic habitats harbour numerous novel uncultured archaea whose metabolic and ecological roles remain to be elucidated. Until recently, it was believed that energy generation via dissimilatory reduction of sulfur compounds is not functional at salt saturation conditions. Recent discovery of the strictly anaerobic acetotrophic Halanaeroarchaeum compels to change both this assumption and the traditional view on haloarchaea as aerobic heterotrophs. Here we report on isolation and characterization of a novel group of strictly anaerobic lithoheterotrophic haloarchaea, which we propose to classify as a new genus Halodesulfurarchaeum. Members of this previously unknown physiological group are capable of utilising formate or hydrogen as electron donors and elemental sulfur, thiosulfate or dimethylsulfoxide as electron acceptors. Using genome-wide proteomic analysis we have detected the full set of enzymes required for anaerobic respiration and analysed their substrate-specific expression. Such advanced metabolic plasticity and type of respiration, never seen before in haloarchaea, empower the wide distribution of Halodesulfurarchaeum in hypersaline inland lakes, solar salterns, lagoons and deep submarine anoxic brines. The discovery of this novel functional group of sulfur-respiring haloarchaea strengthens the evidence of their possible role in biogeochemical sulfur cycling linked to the terminal anaerobic carbon mineralisation in so far overlooked hypersaline anoxic habitats.

  8. Change in Microbial Community with Salinity in the Sediment of Lake Chaka, a hypersaline lake in Northwestern China

    NASA Astrophysics Data System (ADS)

    Jiang, H.; Yu, B.; Dong, H.; Li, Y.; Zhang, C.

    2005-12-01

    Lake Chaka (36°18'-36°45'N,99°02'-99°12'E), 3800 m above sea level, is located on the Qinghai-Tibetan Plateau, northwestern China, where semi-arid continental climate dominates. The basin of Lake Chaka is about 80 km long and 30 km wide. Strong evaporation and little precipitation (2264 mm evaporation versus 224 mm rainfall/year) in this area have resulted in a nearly dry lake and high salinity (21%). The pH of lake water is 7.4. In November 2004, a sediment core of 10 m in length was collected in Lake Chaka. This sediment core covered a salinity gradient from fresh water at the bottom of the core (10-m depth) to near salt saturation at the surface. Mineralogy also changed with depth, ranging from mud-fine sands at the bottom to mirabilite (Na2SO4) and gypsum in the middle to halite near the top. The biomass determined by acridine orange direct count (AODC) in the sediment core was about 108 cells per gram of wet sample from the bottom to the top. Microbial diversity and community structure as determined by phospholipid fatty acid analysis (PFLA) and 16S rRNA gene analyses in the sediment systematically changed with increasing salinity. Overall, microbial diversity decreased with increasing salinity. At the bottom, freshwater microorganisms are dominant. Near the top of the core, halophilic bacteria and archaea are predominant microorganisms. This systematic change in microbial diversity and community structure is a result of microbial response to progressive increase in salinity in the last 50,000 years.

  9. Denitrification in a hypersaline lake-aquifer system (Pétrola Basin, Central Spain): the role of recent organic matter and Cretaceous organic rich sediments.

    PubMed

    Gómez-Alday, J J; Carrey, R; Valiente, N; Otero, N; Soler, A; Ayora, C; Sanz, D; Muñoz-Martín, A; Castaño, S; Recio, C; Carnicero, A; Cortijo, A

    2014-11-01

    Agricultural regions in semi-arid to arid climates with associated saline wetlands are one of the most vulnerable environments to nitrate pollution. The Pétrola Basin was declared vulnerable to NO3(-) pollution by the Regional Government in 1998, and the hypersaline lake was classified as a heavily modified body of water. The study assessed groundwater NO3(-) through the use of multi-isotopic tracers (δ(15)N, δ(34)S, δ(13)C, δ(18)O) coupled to hydrochemistry in the aquifer connected to the eutrophic lake. Hydrogeologically, the basin shows two main flow components: regional groundwater flow from recharge areas (Zone 1) to the lake (Zone 2), and a density-driven flow from surface water to the underlying aquifer (Zone 3). In Zones 1 and 2, δ(15)NNO3 and δ(18)ONO3 suggest that NO3(-) from slightly volatilized ammonium synthetic fertilizers is only partially denitrified. The natural attenuation of NO3(-) can occur by heterotrophic reactions. However, autotrophic reactions cannot be ruled out. In Zone 3, the freshwater-saltwater interface (down to 12-16 m below the ground surface) is a reactive zone for NO3(-) attenuation. Tritium data suggest that the absence of NO3(-) in the deepest zones of the aquifer under the lake can be attributed to a regional groundwater flow with long residence time. In hypersaline lakes the geometry of the density-driven flow can play an important role in the transport of chemical species that can be related to denitrification processes. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Abundance, Distribution, and Activity of Fe(II)-Oxidizing and Fe(III)-Reducing Microorganisms in Hypersaline Sediments of Lake Kasin, Southern Russia

    PubMed Central

    Emmerich, Maren; Bhansali, Ankita; Lösekann-Behrens, Tina; Schröder, Christian; Kappler, Andreas

    2012-01-01

    The extreme osmotic conditions prevailing in hypersaline environments result in decreasing metabolic diversity with increasing salinity. Various microbial metabolisms have been shown to occur even at high salinity, including photosynthesis as well as sulfate and nitrate reduction. However, information about anaerobic microbial iron metabolism in hypersaline environments is scarce. We studied the phylogenetic diversity, distribution, and metabolic activity of iron(II)-oxidizing and iron(III)-reducing Bacteria and Archaea in pH-neutral, iron-rich salt lake sediments (Lake Kasin, southern Russia; salinity, 348.6 g liter−1) using a combination of culture-dependent and -independent techniques. 16S rRNA gene clone libraries for Bacteria and Archaea revealed a microbial community composition typical for hypersaline sediments. Most-probable-number counts confirmed the presence of 4.26 × 102 to 8.32 × 103 iron(II)-oxidizing Bacteria and 4.16 × 102 to 2.13 × 103 iron(III)-reducing microorganisms per gram dry sediment. Microbial iron(III) reduction was detected in the presence of 5 M NaCl, extending the natural habitat boundaries for this important microbial process. Quantitative real-time PCR showed that 16S rRNA gene copy numbers of total Bacteria, total Archaea, and species dominating the iron(III)-reducing enrichment cultures (relatives of Halobaculum gomorrense, Desulfosporosinus lacus, and members of the Bacilli) were highest in an iron oxide-rich sediment layer. Combined with the presented geochemical and mineralogical data, our findings suggest the presence of an active microbial iron cycle at salt concentrations close to the solubility limit of NaCl. PMID:22504804

  11. Quantity and quality of groundwater discharge in a hypersaline lake environment

    USGS Publications Warehouse

    Anderson, R.B.; Naftz, D.L.; Day-Lewis, F. D.; Henderson, R.D.; Rosenberry, D.O.; Stolp, B.J.; Jewell, P.

    2014-01-01

    Geophysical and geochemical surveys were conducted to understand groundwater discharge to Great Salt Lake (GSL) and assess the potential significance of groundwater discharge as a source of selenium (Se). Continuous resistivity profiling (CRP) focusing below the sediment/water interface and fiber-optic distributed temperature sensing (FO-DTS) surveys were conducted along the south shore of GSL. FO-DTS surveys identified persistent cold-water temperature anomalies at 10 separate locations. Seepage measurements were conducted at 17 sites (mean seepage rate = 0.8 cm/day). High resistivity anomalies identified by the CRP survey were likely a mirabilite (Na2SO4·10H2O) salt layer acting as a semi-confining layer for the shallow groundwater below the south shore of the lake. Positive seepage rates measured along the near-shore areas of GSL indicate that a ∼1-m thick oolitic sand overlying the mirabilite layer is likely acting as a shallow, unconfined aquifer. Using the average seepage rate of 0.8 cm/day over an area of 1.6 km2, an annual Se mass loading to GSL of 23.5 kg was estimated. Determination of R/Ra values (calculated 3He/4He ratio over the present-day atmospheric 3He/4He ratio) 34S and δ18O isotopic values in samples of dissolved sulfate from the shallow groundwater below the mirabilite are almost identical to the isotopic signature of the mirabilite core material. The saturation index calculated for groundwater samples using PHREEQC indicates the water is at equilibrium with mirabilite. Water samples collected from GSL immediately off shore contained Se concentrations that were 3–4 times higher than other sampling sites >25 km offshore from the study site and may be originating from less saline groundwater seeps mixing with the more saline water from GSL. Additional evidence for mixing with near shore seeps is found in the δD and δ18O isotopic values and Br:Cl ratios. Geochemical modeling for a water sample collected in the vicinity of the study area

  12. A new method of quantifying discharge of small rivers into lakes and inland seas

    NASA Astrophysics Data System (ADS)

    Osadchiev, Alexander; Zavialov, Peter

    2014-05-01

    Continental discharge is an important component of the global hydrological cycle, providing the majority of the input part of the ocean water balance. Buoyant inflow usually causes surface density stratification at the large shelf areas, and plays a significant role in physical, chemical, and biological processes there that is especially important for the lakes and inland seas. Although there is a lack of discharge data for most of rivers in a global scale. Regular direct measurements of discharge are performed only for a relatively small number of rivers, generally the biggest ones or ones that flow through densely populated areas. Within this problem an indirect method of assuming a volume of river discharge was developed. The general idea of the method is the following. Firstly, the spatial surface spread of the plume generated by the considered river discharge is identified using high resolution satellite imagery of the coastal zone adjacent to the river estuary. Secondly, a series of numerical simulations of the river runoff spread is performed under various prescribed external forcing conditions which include the discharge rate. Varying forcing conditions we iteratively improve the accordance between simulated and observed river plumes therefore consequentially specifying the value of river discharge. The developed method was applied and validated against in situ date for several rivers feeding the Black Sea. Practical importance of this work consists in the fact, that the suggested method is an alternative for the expensive and laborious direct measurements of the river discharge, which are used nowadays.

  13. Quantity and quality of groundwater discharge in a hypersaline lake environment

    NASA Astrophysics Data System (ADS)

    Anderson, R. B.; Naftz, D. L.; Day-Lewis, F. D.; Henderson, R. D.; Rosenberry, D. O.; Stolp, B. J.; Jewell, P.

    2014-05-01

    Geophysical and geochemical surveys were conducted to understand groundwater discharge to Great Salt Lake (GSL) and assess the potential significance of groundwater discharge as a source of selenium (Se). Continuous resistivity profiling (CRP) focusing below the sediment/water interface and fiber-optic distributed temperature sensing (FO-DTS) surveys were conducted along the south shore of GSL. FO-DTS surveys identified persistent cold-water temperature anomalies at 10 separate locations. Seepage measurements were conducted at 17 sites (mean seepage rate = 0.8 cm/day). High resistivity anomalies identified by the CRP survey were likely a mirabilite (Na2SO4·10H2O) salt layer acting as a semi-confining layer for the shallow groundwater below the south shore of the lake. Positive seepage rates measured along the near-shore areas of GSL indicate that a ∼1-m thick oolitic sand overlying the mirabilite layer is likely acting as a shallow, unconfined aquifer. Using the average seepage rate of 0.8 cm/day over an area of 1.6 km2, an annual Se mass loading to GSL of 23.5 kg was estimated. Determination of R/Ra values (calculated 3He/4He ratio over the present-day atmospheric 3He/4He ratio) <1 and tritium activities of 1.2-2.0 tritium units in groundwater within and below the mirabilite layer indicates a convergence of regional and local groundwater flow paths discharging into GSL. Groundwater within and below the mirabilite layer obtains its high sulfate salinity from the dissolution of mirabilite. The δ34S and δ18O isotopic values in samples of dissolved sulfate from the shallow groundwater below the mirabilite are almost identical to the isotopic signature of the mirabilite core material. The saturation index calculated for groundwater samples using PHREEQC indicates the water is at equilibrium with mirabilite. Water samples collected from GSL immediately off shore contained Se concentrations that were 3-4 times higher than other sampling sites >25 km offshore from

  14. Molecular Analysis of the Microbial Communities of Mars Analog Lakes in Western Australia

    NASA Astrophysics Data System (ADS)

    Mormile, Melanie R.; Hong, Bo-Young; Benison, Kathleen C.

    2009-12-01

    Unique, shallow interdune lakes and groundwaters with extremely low pH and high salinity exist in Australia, along with nearby lakes that possess higher pH values. These acidic hypersaline environments are possibly the best modern terrestrial analogues for past martian environments. However, no previous microbiological analyses of these lakes have been conducted. During the Australian winter of 2005, water samples were taken from several hypersaline lakes located in southern Western Australia that possessed acidic to slightly alkaline pH. These samples were subjected to molecular analysis to identify bacterial communities. DNA extraction and polymerase chain reaction (PCR) amplification of the 16S rRNA gene sequences, by using universal bacterial primers, were also performed on the samples. Extracted DNA was amplified with 1070 forward and 1392 GC-clamped reverse primers and analyzed by using denaturant gradient gel electrophoresis (DGGE). In addition, libraries were developed from DNA retrieved from four lakes, including a marginal marine neutral lake, an inland neutral lake, and two inland acid lakes, and selected clones with distinct operational taxonomic units were sequenced. The DGGE profiles and clone sequence data indicate that there are distinct, abundant, and diverse microbial populations in these Australian hypersaline environments, especially the acidic ones. These results are significant for two reasons: (1) they provide the first microbiological survey of natural acid saline lakes and (2) they hint at the possibility that there could have been a diverse microbial population in acidic hypersaline environments on Mars.

  15. Ornithinibacillus halophilus sp. nov., a moderately halophilic, Gram-stain-positive, endospore-forming bacterium from a hypersaline lake.

    PubMed

    Bagheri, Maryam; Amoozegar, Mohammad Ali; Schumann, Peter; Didari, Maryam; Mehrshad, Malihe; Spröer, Cathrin; Sánchez-Porro, Cristina; Ventosa, Antonio

    2013-03-01

    A novel Gram-stain-positive, moderately halophilic bacterium, designated strain G8B(T), was isolated from water of the hypersaline lake Aran-Bidgol in Iran and characterized taxonomically using a polyphasic approach. Cells of strain G8B(T) were rod-shaped, motile and produced oval endospores at a terminal position in swollen sporangia. Strain G8B(T) was strictly aerobic, catalase-positive and oxidase-negative. The strain was able to grow at NaCl concentrations of 0.5-12.5 % (w/v), with optimum growth occurring at 5-7.5 % (w/v) NaCl. The optimum temperature and pH for growth were 35-40 °C and pH 7.5-8.0, respectively. On the basis of 16S rRNA gene sequence analysis, strain G8B(T) was shown to belong to the genus Ornithinibacillus within the phylum Firmicutes and showed closest phylogenetic similarity with Ornithinibacillus bavariensis WSBC 24001(T) (97.6 %). The DNA G+C content of strain G8B(T) was 36.9 mol%. The major cellular fatty acids of strain G8B(T) were anteiso-C15 : 0, anteiso-C17 : 0, iso-C15 : 0 and iso-C16 : 0, and its polar lipid pattern consisted of phosphatidylglycerol, diphosphatidylglycerol, four unknown phospholipids and an unknown aminolipid. The isoprenoid quinones were MK-7 (98 %) and MK-8 (2 %). Strain G8B(T) contained a peptidoglycan of type A4β, l-Orn-d-Asp. All these features confirmed the placement of isolate G8B(T) within the genus Ornithinibacillus. DNA-DNA hybridization experiments revealed a low level of relatedness (6 %) between strain G8B(T) and Ornithinibacillus bavariensis DSM 15681(T). On the basis of evidence from this study, a novel species of the genus Ornithinibacillus, Ornithinibacillus halophilus sp. nov., is proposed, with strain G8B(T) ( = IBRC-M 10683(T) = KCTC 13822(T)) as the type strain.

  16. Biological activity at the limits of life: Microbial cycling of C, S and N in cold, permanently stratified, hypersaline Lake Vanda, Antarctica.

    NASA Astrophysics Data System (ADS)

    Joye, S. B.; Schutte, C.; Samarkin, V.; Casciotti, K. L.; Madigan, M.; Saxton, M.

    2014-12-01

    The lakes of the McMurdo Dry Valleys (MCM) are the only perennially ice covered lakes on Earth and are the primary refuge for life in this hyper-arid polar desert. As a result of the ice cover and an uncoupled day/night cycle, the physical and biogeochemical processes in the lakes are highly unusual, with biogeochemical gradients and concentrations of specific compounds often exceeding those found in other aquatic ecosystems on Earth. These lakes are ideal systems for the study of redox-sensitive biogeochemical processes, model systems for understanding the effects of global climate change on polar ecosystems, end-member systems that provide insight into biogeochemical and limnological dynamics in meromictic lakes, analogues for life on other planets, and perfect systems to study microbial life at its thermodynamic limits. Lake Vanda, in the Wright valley, is relatively deep (73 m), hypersaline and has anoxic bottom water. High concentrations of chacotrophic salts results in low water activities that exert further challenges on microbial life. We collected details geochemical profiles of nutrients, major ions, dissolved gases, and redox metabolites and measured rates of microbially-mediated processes that cycle carbon, nitrogen and sulfur in the lakes waters and sediments. Despite the harsh and extreme nature of Lake Vanda and the thermodynamic barriers to microbially-mediated geochemical reactions, microorganisms are not only present in the lake but they mediate a diverse suite of geochemical processes. Statistical correlations between geochemical parameters, microbial activity and microbial community composition shed light on the factors that regulate and limit microbial activity in this unique extreme environment.

  17. Deriving Equations of State for Specific Lakes and Inland Seas from Laboratory Measurements

    NASA Astrophysics Data System (ADS)

    Andrulionis, Natalia; Zavialov, Ivan; Zavialov, Peter; Osadchiev, Alexander; Kolokolova, Alexandra; Alukaeva, Alevtina; Izhitskiy, Alexander; Izhitskaya, Elena

    2017-04-01

    The equation of state is the dependence of water density on temperature, salinity, and pressure. It is important in many respects, in particular, for numerical modeling of marine systems. The widely used UNESCO equation of state, as well as the more recent and general TEOS-10 equation, are intended for the ocean waters. Hence, they are confined to salinities below 40 ‰ and, even more restrictively, valid only for ionic salt composition characteristic for the ocean. Both conditions do not hold for many lakes. Moreover, significant deviations of the ionic composition from the oceanic one have been documented for coastal zones, especially those exposed to river discharges. Therefore, the objective of this study was to find equations of state for areas or water bodies with non-oceanic ionic salt composition. In order to obtain the required equations, we analyzed water samples obtained in expeditions of 2014-2016 from the Black Sea, the Aral Sea, Lake Issyk-Kul and Caspian Sea. The filtered samples were submitted to high accuracy (up to 0.00001 g/cm3) density measurements in laboratory using the Anton Paar DMA 5000M in the temperature range from 1 to 29°C. The absolute salinity values of the initial samples were obtained through the dry residue method. Further, we diluted the samples by purified deionized water to produce different salinities. To control the accuracy of the dilution process, we used a reference sample of standard IAPSO-certified seawater at 35‰. The density versus salinity and temperature data obtained thereby were then approximated by a best fitting 2-order polynomial surface using the least squares method. This procedure yielded the approximate empirical equations of state for the selected marine areas (the Russian Black Sea shelf) and inland water bodies (the Aral Sea, the Lake Issyk-Kul, the Caspian Sea). The newly derived equations - even the one for the Black Sea shelf - are different from the oceanic equation significantly within the

  18. Historical and anthropogenic factors affecting the population genetic structure of Ontario's inland lake populations of Walleye (Sander vitreus).

    PubMed

    Walter, Ryan P; Cena, Christopher J; Morgan, George E; Heath, Daniel D

    2012-01-01

    Populations existing in formerly glaciated areas often display composite historical and contemporary patterns of genetic structure. For Canadian freshwater fishes, population genetic structure is largely reflective of dispersal from glacial refugia and isolation within drainage basins across a range of scales. Enhancement of sport fisheries via hatchery stocking programs and other means has the potential to alter signatures of natural evolutionary processes. Using 11 microsatellite loci genotyped from 2182 individuals, we analyzed the genetic structure of 46 inland lake walleye (Sander vitreus) populations spanning five major drainage basins within the province of Ontario, Canada. Population genetic analyses coupled with genotype assignment allowed us to: 1) characterize broad- and fine-scale genetic structure among Ontario walleye populations; and 2) determine if the observed population divergence is primarily due to natural or historical processes, or recent anthropogenic events. The partitioning of genetic variation revealed higher genetic divergence among lakes than among drainage basins or proposed ancestries-indicative of relatively high isolation among lakes, study-wide. Walleye genotypes were clustered into three major groups, likely reflective of Missourian, Mississippian, and Atlantic glacial refugial ancestry. Despite detectable genetic signatures indicative of anthropogenic influences, province-wide spatial genetic structure remains consistent with the hypothesis of dispersal from distinct glacial refugia and subsequent isolation of lakes within primary drainage basins. Our results provide a novel example of minimal impacts from fishery enhancement to the broad-scale genetic structure of inland fish populations.

  19. Halobellus rarus sp. nov., a halophilic archaeon from an inland salt lake of China.

    PubMed

    Zhang, Wen-Jiao; Han, Dong; Qiu, Xing-Xing; Zhao, Mei-Lin; Mou, Yun-Zhuang; Cui, Heng-Lin; Li, Zheng-Rong

    2013-09-01

    Two halophilic archaeal strains, YC21(T) and YC77, were isolated from an inland salt lake of China. Both have pleomorphic rod-shaped cells that lyse in distilled water, stain Gram-negative and form red-pigmented colonies. They are neutrophilic, require at least 2.1 M NaCl for growth under the optimum growth temperature of 37 °C. The major polar lipids of the two strains were phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), phosphatidylglycerol sulfate (PGS), two major glycolipids (GL1 and GL2) chromatographically identical to sulfated mannosyl glucosyl diether (S-DGD-1) and mannosyl glucosyl diether (DGD-1), respectively. Trace amounts of two unidentified lipids (GL0-1 and GL0-2) were also detected. The 16S rRNA gene sequences of the two strains are 99.9 % identical, show 94.0-98.9 % similarity to the closest relative members of Halobellus of the family Halobacteriaceae. The rpoB' gene similarity between strains YC21(T) and YC77 is 99.8 % and show 90.3-95.3 % similarity to the closest relative members of Halobellus. The DNA G+C content of strains YC21(T) and YC77 were 66.1 and 66.2 mol%, respectively. The DNA-DNA hybridization value between strain YC20(T) and strain YC77 was 89 %, and the two strains showed low DNA-DNA relatedness with Halobellus limi TBN53(T), the most related member of Halobellus. The phenotypic, chemotaxonomic and phylogenetic properties suggest that strains YC21(T) and YC77 represent a novel species of the genus Halobellus, for which the name Halobellus rarus sp. nov. is proposed. The type strain is YC21(T) (=CGMCC 1.12121(T) = JCM 18362(T)).

  20. 46 CFR 11.442 - Service requirements for master of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Service requirements for master of Great Lakes and... ENDORSEMENTS Professional Requirements for Deck Officers § 11.442 Service requirements for master of Great... to qualify an applicant for an endorsement as master of Great Lakes and inland steam or motor...

  1. State and regional water-quality characteristics and trophic conditions of Michigan's inland lakes, 2001-2005

    USGS Publications Warehouse

    Fuller, L.M.; Minnerick, R.J.

    2008-01-01

    The U.S. Geological Survey and the Michigan Department of Environmental Quality are jointly monitoring selected water-quality constituents of inland lakes through 2015 as part of Michigan’s Lake Water Quality Assessment program. During 2001–2005, 433 lake basins from 364 inland lakes were monitored for baseline water-quality conditions and trophic status. This report summarizes the water-quality characteristics and trophic conditions of those monitored lake basins throughout the State. Regional variation of water quality in lake basins was examined by grouping on the basis of the five Omernik level III ecoregions within Michigan. Concentrations of most constituents measured were significantly different between ecoregions. Less regional variation of phosphorus concentrations was noted between Northern Lakes and Forests (50) and North Central Hardwoods (51) ecoregions during summer possibly because water samples were collected when lake productivity was high; hence the utilization of the limited amount of phosphorus by algae and macrophytes may have resulted in the more uniform concentrations between these two ecoregions. Concentrations of common ions (calcium, magnesium, potassium, sodium, chloride, and sulfate) measured in the spring typically were higher in the Michigan southern Lower Peninsula in the Eastern Corn Belt Plains (55), Southern Michigan/Northern Indiana Drift Plains (56), and Huron/Erie Lake Plains (57) ecoregions. Most ions whose concentrations were less than the minimum reporting levels or were nondetectable were from lakes in the Michigan northern Lower Peninsula and the Upper Peninsula in the Northern Lakes and Forests (50) and North Central Hardwoods (51) ecoregions. Chlorophyll a concentrations followed a similar distribution pattern. Measured properties such as pH and specific conductance (indicative of dissolved solids) also showed a regional relation. The lakes with the lowest pH and specific conductance were generally in the western

  2. Inputs and internal cycling of nitrogen to a causeway influenced, hypersaline lake, Great Salt Lake, Utah, USA

    USGS Publications Warehouse

    Naftz, David L.

    2017-01-01

    Nitrogen inputs to Great Salt Lake (GSL), located in the western USA, were quantified relative to the resident nitrogen mass in order to better determine numeric nutrient criteria that may be considered at some point in the future. Total dissolved nitrogen inputs from four surface-water sources entering GSL were modeled during the 5-year study period (2010–2014) and ranged from 1.90 × 106 to 5.56 × 106 kg/year. The railroad causeway breach was a significant conduit for the export of dissolved nitrogen from Gilbert to Gunnison Bay, and in 2011 and 2012, net losses of total nitrogen mass from Gilbert Bay via the Causeway breach were 9.59 × 105 and 1.51 × 106 kg. Atmospheric deposition (wet + dry) was a significant source of nitrogen to Gilbert Bay, exceeding the dissolved nitrogen load contributed via the Farmington Bay causeway surface-water input by >100,000 kg during 2 years of the study. Closure of two railroad causeway culverts in 2012 and 2013 likely initiated a decreasing trend in the volume of the higher density Deep Brine Layer and associated declines in total dissolved nitrogen mass contained in this layer. The large dissolved nitrogen pool in Gilbert Bay relative to the amount of nitrogen contributed by surface-water inflow sources is consistent with the terminal nature of GSL and the predominance of internal nutrient cycling. The opening of the new railroad causeway breach in 2016 will likely facilitate more efficient bidirectional flow between Gilbert and Gunnison Bays, resulting in potentially substantial changes in nutrient pools within GSL.

  3. Evaluation of chlorophyll-a retrieval algorithms based on MERIS bands for optically varying eutrophic inland lakes.

    PubMed

    Lyu, Heng; Li, Xiaojun; Wang, Yannan; Jin, Qi; Cao, Kai; Wang, Qiao; Li, Yunmei

    2015-10-15

    Fourteen field campaigns were conducted in five inland lakes during different seasons between 2006 and 2013, and a total of 398 water samples with varying optical characteristics were collected. The characteristics were analyzed based on remote sensing reflectance, and an automatic cluster two-step method was applied for water classification. The inland waters could be clustered into three types, which we labeled water types I, II and III. From water types I to III, the effect of the phytoplankton on the optical characteristics gradually decreased. Four chlorophyll-a retrieval algorithms for Case II water, a two-band, three-band, four-band and SCI (Synthetic Chlorophyll Index) algorithm were evaluated for three water types based on the MERIS bands. Different MERIS bands were used for the three water types in each of the four algorithms. The four algorithms had different levels of retrieval accuracy for each water type, and no single algorithm could be successfully applied to all water types. For water types I and III, the three-band algorithm performed the best, while the four-band algorithm had the highest retrieval accuracy for water type II. However, the three-band algorithm is preferable to the two-band algorithm for turbid eutrophic inland waters. The SCI algorithm is recommended for highly turbid water with a higher concentration of total suspended solids. Our research indicates that the chlorophyll-a concentration retrieval by remote sensing for optically contrasted inland water requires a specific algorithm that is based on the optical characteristics of inland water bodies to obtain higher estimation accuracy. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Trends and stability of inland fishery resources in Japanese lakes: introduction of exotic piscivores as a driver.

    PubMed

    Matsuzaki, Shin-ichiro S; Kadoya, Taku

    2015-07-01

    Although many studies have focused on marine resources, few studies have considered the resources of inland fisheries. Inland fishery resources are typically either monitored on the basis of catch data alone or are not assessed quantitatively at all, despite their social, economic, and ecological importance. Because freshwater ecosystems have been severely degraded by human activities, evaluating the trends and current status of fishery resources and assessing their drivers are urgent tasks. We compiled long-term data on the annual catch, fishing effort, and fishing power of 23 Japanese lakes, using two sets of government statistics that date back to the 1950s, which were previously neglected because of the large number of missing values. Using Bayesian state-space models, we examined the trajectories of the catch per unit effort (CPUE) of entire communities, considering changes in fishing effort and fishing power, and quantified both changes in the CPUE over the 10-, 20-, and 30-year periods preceding 2008 and the temporal detrended stability of the CPUE over the three periods. We also investigated the relationships among the CPUE changes and stability, anthropogenic drivers, and lake morphometric characteristics. The CPUE declined in 17, 19, and 15 of the 23 lakes over the past 10-, 20-, and 30-year periods, respectively. Our macroecological analyses demonstrate that the functional group richness of exotic piscivores was the most important predictor of changes in the CPUE among the drivers we considered. The stability of the CPUE was positively related to lake area; larger lakes have more stable CPUE. The functional group richness of exotic piscivores also negatively affected the stability of the CPUE. The effect of overfishing was considered to be small because both fishing effort and power declined in almost all of the lakes. Thus, our findings suggest that increasing exotic piscivore species may diminish the resources and their stability, particularly in

  5. Predictive models for Escherichia coli concentrations at inland lake beaches and relationship of model variables to pathogen detection

    USGS Publications Warehouse

    Francy, Donna S.; Stelzer, Erin A.; Duris, Joseph W.; Brady, Amie M.G.; Harrison, John H.; Johnson, Heather E.; Ware, Michael W.

    2013-01-01

    Predictive models, based on environmental and water quality variables, have been used to improve the timeliness and accuracy of recreational water quality assessments, but their effectiveness has not been studied in inland waters. Sampling at eight inland recreational lakes in Ohio was done in order to investigate using predictive models for Escherichia coli and to understand the links between E. coli concentrations, predictive variables, and pathogens. Based upon results from 21 beach sites, models were developed for 13 sites, and the most predictive variables were rainfall, wind direction and speed, turbidity, and water temperature. Models were not developed at sites where the E. coli standard was seldom exceeded. Models were validated at nine sites during an independent year. At three sites, the model resulted in increased correct responses, sensitivities, and specificities compared to use of the previous day's E. coli concentration (the current method). Drought conditions during the validation year precluded being able to adequately assess model performance at most of the other sites. Cryptosporidium, adenovirus, eaeA (E. coli), ipaH (Shigella), and spvC (Salmonella) were found in at least 20% of samples collected for pathogens at five sites. The presence or absence of the three bacterial genes was related to some of the model variables but was not consistently related to E. coli concentrations. Predictive models were not effective at all inland lake sites; however, their use at two lakes with high swimmer densities will provide better estimates of public health risk than current methods and will be a valuable resource for beach managers and the public.

  6. Predictive models for Escherichia coli concentrations at inland lake beaches and relationship of model variables to pathogen detection.

    PubMed

    Francy, Donna S; Stelzer, Erin A; Duris, Joseph W; Brady, Amie M G; Harrison, John H; Johnson, Heather E; Ware, Michael W

    2013-03-01

    Predictive models, based on environmental and water quality variables, have been used to improve the timeliness and accuracy of recreational water quality assessments, but their effectiveness has not been studied in inland waters. Sampling at eight inland recreational lakes in Ohio was done in order to investigate using predictive models for Escherichia coli and to understand the links between E. coli concentrations, predictive variables, and pathogens. Based upon results from 21 beach sites, models were developed for 13 sites, and the most predictive variables were rainfall, wind direction and speed, turbidity, and water temperature. Models were not developed at sites where the E. coli standard was seldom exceeded. Models were validated at nine sites during an independent year. At three sites, the model resulted in increased correct responses, sensitivities, and specificities compared to use of the previous day's E. coli concentration (the current method). Drought conditions during the validation year precluded being able to adequately assess model performance at most of the other sites. Cryptosporidium, adenovirus, eaeA (E. coli), ipaH (Shigella), and spvC (Salmonella) were found in at least 20% of samples collected for pathogens at five sites. The presence or absence of the three bacterial genes was related to some of the model variables but was not consistently related to E. coli concentrations. Predictive models were not effective at all inland lake sites; however, their use at two lakes with high swimmer densities will provide better estimates of public health risk than current methods and will be a valuable resource for beach managers and the public.

  7. Predictive Models for Escherichia coli Concentrations at Inland Lake Beaches and Relationship of Model Variables to Pathogen Detection

    PubMed Central

    Stelzer, Erin A.; Duris, Joseph W.; Brady, Amie M. G.; Harrison, John H.; Johnson, Heather E.; Ware, Michael W.

    2013-01-01

    Predictive models, based on environmental and water quality variables, have been used to improve the timeliness and accuracy of recreational water quality assessments, but their effectiveness has not been studied in inland waters. Sampling at eight inland recreational lakes in Ohio was done in order to investigate using predictive models for Escherichia coli and to understand the links between E. coli concentrations, predictive variables, and pathogens. Based upon results from 21 beach sites, models were developed for 13 sites, and the most predictive variables were rainfall, wind direction and speed, turbidity, and water temperature. Models were not developed at sites where the E. coli standard was seldom exceeded. Models were validated at nine sites during an independent year. At three sites, the model resulted in increased correct responses, sensitivities, and specificities compared to use of the previous day's E. coli concentration (the current method). Drought conditions during the validation year precluded being able to adequately assess model performance at most of the other sites. Cryptosporidium, adenovirus, eaeA (E. coli), ipaH (Shigella), and spvC (Salmonella) were found in at least 20% of samples collected for pathogens at five sites. The presence or absence of the three bacterial genes was related to some of the model variables but was not consistently related to E. coli concentrations. Predictive models were not effective at all inland lake sites; however, their use at two lakes with high swimmer densities will provide better estimates of public health risk than current methods and will be a valuable resource for beach managers and the public. PMID:23291550

  8. Complete genome sequence of Desulfurivibrio alkaliphilus strain AHT2T, a haloalkaliphilic sulfidogen from Egyptian hypersaline alkaline lakes

    SciTech Connect

    Melton, Emily Denise; Sorokin, Dimitry Y.; Overmars, Lex; Chertkov, Olga; Clum, Alicia; Pillay, Manoj; Ivanova, Natalia; Shapiro, Nicole; Kyrpides, Nikos C.; Woyke, Tanja; Lapidus, Alla L.; Muyzer, Gerard

    2016-09-08

    Desulfurivibrio alkaliphilus strain AHT2T is a strictly anaerobic sulfidogenic haloalkaliphile isolated from a composite sediment sample of eight hypersaline alkaline lakes in the Wadi al Natrun valley in the Egyptian Libyan Desert. D. alkaliphilus AHT2T is Gram-negative and belongs to the family Desulfobulbaceae within the Deltaproteobacteria. Here we report its genome sequence, which contains a 3.10 Mbp chromosome. Here, D. alkaliphilus AHT2T is adapted to survive under highly alkaline and moderately saline conditions and therefore, is relevant to the biotechnology industry and life under extreme conditions. For these reasons, D. alkaliphilus AHT2T was sequenced by the DOE Joint Genome Institute as part of the Community Science Program.

  9. Predicting water quality by relating secchi-disk transparency and chlorophyll a measurements to satellite imagery for Michigan Inland Lakes, August 2002

    USGS Publications Warehouse

    Fuller, L.M.; Aichele, S.S.; Minnerick, R.J.

    2004-01-01

    Inland lakes are an important economic and environmental resource for Michigan. The U.S. Geological Survey and the Michigan Department of Environmental Quality have been cooperatively monitoring the quality of selected lakes in Michigan through the Lake Water Quality Assessment program. Through this program, approximately 730 of Michigan's 11,000 inland lakes will be monitored once during this 15-year study. Targeted lakes will be sampled during spring turnover and again in late summer to characterize water quality. Because more extensive and more frequent sampling is not economically feasible in the Lake Water Quality Assessment program, the U.S. Geological Survey and Michigan Department of Environmental Quality investigate the use of satellite imagery as a means of estimating water quality in unsampled lakes. Satellite imagery has been successfully used in Minnesota, Wisconsin, and elsewhere to compute the trophic state of inland lakes from predicted secchi-disk measurements. Previous attempts of this kind in Michigan resulted in a poorer fit between observed and predicted data than was found for Minnesota or Wisconsin. This study tested whether estimates could be improved by using atmospherically corrected satellite imagery, whether a more appropriate regression model could be obtained for Michigan, and whether chlorophyll a concentrations could be reliably predicted from satellite imagery in order to compute trophic state of inland lakes. Although the atmospheric-correction did not significantly improve estimates of lake-water quality, a new regression equation was identified that consistently yielded better results than an equation obtained from the literature. A stepwise regression was used to determine an equation that accurately predicts chlorophyll a concentrations in northern Lower Michigan.

  10. Potential effects of climate change on inland glacial lakes and implications for lake-dependent biota in Wisconsin: final report April 2013

    USGS Publications Warehouse

    Meyer, Michael W.; Walker, John F.; Kenow, Kevin P.; Rasmussen, Paul W.; Garrison, Paul J.; Hanson, Paul C.; Hunt, Randall J.

    2013-01-01

    F statewide, and an increase in precipitation of 1”–2”. However, summer precipitation in the northern part of the state is expected to be less and winter precipitation will be greater. By the end of the 21st century, the magnitude of changes in temperature and precipitation are expected to intensify. Such climatic changes have altered, and would further alter hydrological, chemical, and physical properties of inland lakes. Lake-dependent wildlife sensitive to changes in water quality, are particularly susceptible to lake quality-associated habitat changes and are likely to suffer restrictions to current breeding distributions under some climate change scenarios. We have selected the common loon (Gavia immer) to serve as a sentinel lake-dependent piscivorous species to be used in the development of a template for linking primary lake-dependent biota endpoints (e.g., decline in productivity and/or breeding range contraction) to important lake quality indicators. In the current project, we evaluate how changes in freshwater habitat quality (specifically lake clarity) may impact common loon lake occupancy in Wisconsin under detailed climate-change scenarios. In addition, we employ simple land-use/land cover and habitat scenarios to illustrate the potential interaction of climate and land-use/land cover effects. The methods employed here provide a template for studies where integration of physical and biotic models is used to project future conditions under various climate and land use change scenarios. Findings presented here project the future conditions of lakes and loons within an important watershed in northern Wisconsin – of importance to water resource managers and state citizens alike.

  11. Quantifying sample biases of inland lake sampling programs in relation to lake surface area and land use/cover.

    PubMed

    Wagner, Tyler; Soranno, Patricia A; Cheruvelil, Kendra Spence; Renwick, William H; Webster, Katherine E; Vaux, Peter; Abbitt, Robbyn J F

    2008-06-01

    We quantified potential biases associated with lakes monitored using non-probability based sampling by six state agencies in the USA (Michigan, Wisconsin, Iowa, Ohio, Maine, and New Hampshire). To identify biases, we compared state-monitored lakes to a census population of lakes derived from the National Hydrography Dataset. We then estimated the probability of lakes being sampled using generalized linear mixed models. Our two research questions were: (1) are there systematic differences in lake area and land use/land cover (LULC) surrounding lakes monitored by state agencies when compared to the entire population of lakes? and (2) after controlling for the effects of lake size, does the probability of sampling vary depending on the surrounding LULC features? We examined the biases associated with surrounding LULC because of the established links between LULC and lake water quality. For all states, we found that larger lakes had a higher probability of being sampled compared to smaller lakes. Significant interactions between lake size and LULC prohibit us from drawing conclusions about the main effects of LULC; however, in general lakes that are most likely to be sampled have either high urban use, high agricultural use, high forest cover, or low wetland cover. Our analyses support the assertion that data derived from non-probability-based surveys must be used with caution when attempting to make generalizations to the entire population of interest, and that probability-based surveys are needed to ensure unbiased, accurate estimates of lake status and trends at regional to national scales.

  12. Identification of sources and seasonal variability of organic matter in Lake Sihwa and surrounding inland creeks, South Korea.

    PubMed

    Lee, Yeonjung; Hong, Seongjin; Kim, Min-Seob; Kim, Dahae; Choi, Bo-Hyung; Hur, Jin; Khim, Jong Seong; Shin, Kyung-Hoon

    2017-06-01

    Coastal areas are subjected to significant allochthonous organic matter deposits from surrounding areas; however, limited information is available on the source and delivery of this organic matter. In this study, to assess seasonal changes in the sources of organic matter in Lake Sihwa (Korea), biodegradability, fluorescence property, and stable isotopic compositions (carbon, nitrogen, and sulfur) of the organic matter were determined. Water samples were collected from the inner lake (n = 9) and inland creeks (n = 10) in five separate events, from November 2012 to October 2013. Organic matter originating from rural, urban, and industrial areas was examined as the potential sources. The organic matter contents and biodegradability in the industrial area were the highest, whereas low concentrations and poor biodegradability of organic matter were found in the rural area, and moderate properties were observed in the urban area. In Lake Sihwa, a large concentration of total organic matter and enhanced biodegradability were observed during March and August. However, main source of organic matter differed between the sampling events. The largest contribution of organic matter, deriving from marine phytoplankton, was found in March. On the other hand, in August, the organic matter originating from the industrial area, which is characterized by high levels of heavy metals and persistent organic pollutants, was significantly increased. Our results could be useful to enhance the management of water bodies aimed at reducing the organic matter concentrations and improving the water quality of Lake Sihwa, and even that of the Yellow Sea.

  13. Natronotalea proteinilytica gen. nov., sp. nov. and Longimonas haloalkaliphila sp. nov., extremely haloalkaliphilic members of the phylum Rhodothermaeota from hypersaline alkaline lakes.

    PubMed

    Sorokin, Dimitry Y; Khijniak, Tatiana V; Galinski, Erwin A; Kublanov, Ilya V

    2017-09-18

    Two proteolytic bacterial strains, BSker2T and BSker3T, were enriched from sediments of hypersaline alkaline lakes in Kulunda Steppe (Altai, Russia) with chicken feathers as substrate, followed by pure culture isolation on hypersaline alkaline media with casein. The cells were non-motile, filamentous, flexible rods. The isolates were obligately aerobic heterotrophs utilizing proteins and peptides as growth substrates. Both were obligate alkaliphiles, but differed in their pH optimum for growth: pH 9.5-9.8 for Bsker2T and pH 8.5-8.8 for BSker3T. The salt range for growth of both isolates was between 2 and 4.5 M total Na+ with an optimum at 2.5-3 M. No organic osmolytes were detected in cells of BSker2T, but they accumulated high intracellular concentrations of K+. The polar lipid fatty acids were dominated by unsaturated C16 and C18 species. The 16S rRNA gene phylogeny indicated that both strains belong to the recently proposed phylum Rhodothermaeota. BSker2T forms a novel genus-level branch, while BSker3T represents a novel species-level member in the genus Longimonas. On the basis of distinct phenotypic and genotypic properties, strain BSker2T (=JCM 31342T=UNIQEM U1009T) is proposed to be classified as a representative of a novel genus and species, Natronotalea proteinilyticagen. nov., sp. nov., and strain BSker3T (=JCM 31343T=UNIQEM U1010T) as a representative of a novel species, Longimonas haloalkaliphila sp. nov.

  14. Is China's fifth-largest inland lake to dry-up? Incorporated hydrological and satellite-based methods for forecasting Hulun lake water levels

    NASA Astrophysics Data System (ADS)

    Cai, Zuansi; Jin, Taoyong; Li, Changyou; Ofterdinger, Ulrich; Zhang, Sheng; Ding, Aizhong; Li, Jiancheng

    2016-08-01

    Hulun Lake, China's fifth-largest inland lake, experienced severe declines in water level in the period of 2000-2010. This has prompted concerns whether the lake is drying up gradually. A multi-million US dollar engineering project to construct a water channel to transfer part of the river flow from a nearby river to maintain the water level was completed in August 2010. This study aimed to advance the understanding of the key processes controlling the lake water level variation over the last five decades, as well as investigate the impact of the river transfer engineering project on the water level. A water balance model was developed to investigate the lake water level variations over the last five decades, using hydrological and climatic data as well as satellite-based measurements and results from land surface modelling. The investigation reveals that the severe reduction of river discharge (-364 ± 64 mm/yr, ∼70% of the five-decade average) into the lake was the key factor behind the decline of the lake water level between 2000 and 2010. The decline of river discharge was due to the reduction of total runoff from the lake watershed. This was a result of the reduction of soil moisture due to the decrease of precipitation (-49 ± 45 mm/yr) over this period. The water budget calculation suggests that the groundwater component from the surrounding lake area as well as surface run off from the un-gauged area surrounding the lake contributed ∼ net 210 Mm3/yr (equivalent to ∼ 100 mm/yr) water inflows into the lake. The results also show that the water diversion project did prevent a further water level decline of over 0.5 m by the end of 2012. Overall, the monthly water balance model gave an excellent prediction of the lake water level fluctuation over the last five decades and can be a useful tool to manage lake water resources in the future.

  15. Ecosystem Alterations and Species Range Shifts: An Atlantic-Mediterranean Cephalaspidean Gastropod in an Inland Egyptian Lake

    PubMed Central

    Malaquias, Manuel António E.

    2016-01-01

    The eastern Atlantic and Mediterranean marine Cephalaspidea gastropod Haminoea orbignyana was collected from Lake Qarun (Fayoum, Egypt), a landlocked lake that has undergone a shift from freshwater to estuarine conditions in the past 100 years. Species identity was confirmed by both morphological (anatomical dissection and scanning electron microscopy) and molecular methods (COI gene phylogeny). Observations suggested a robust population of H. orbignyana in the lake with a density of ca. 64 individuals/m2 and ca. 105 egg masses/m2 during surveys conducted in the summer of 2013. The vast majority of snails and egg masses were found under rocks. Observations of egg masses in the lab showed a gradual change from whitish to yellow-green as the eggs matured and the release of veliger larvae alone after about a week. Although adult cephalaspideans readily consumed filamentous red and green algae, and cyanobacteria, laboratory trials showed that they consumed significantly more of the red alga Ceramium sp., than of the green alga Cladophora glomerata, with consumption of Oscillatoria margaritifera being similar to those on the two algae. When grown on these resources for 16 days, H. orbignyana maintained their mass on the rhodophyte and cyanobacterium, but not in starvation controls. No cephalaspideans grew over the course of this experiment. Lake Qarun has been periodically restocked with Mediterranean fishes and prawns since the 1920s to maintain local fisheries, which represents a possible route of colonization for H. orbignyana. Yet, based on literature records, it seems more likely that invasion of the lake by this gastropod species has occurred only within the last 20 years. As human activities redistribute species through direct and indirect means, the structure of the community of this inland lake has become unpredictable and the long-term effects of these recent introductions are unknown. PMID:27248835

  16. The LANDSAT-1 multispectral scanner as a tool in the classification of inland lakes

    NASA Technical Reports Server (NTRS)

    Boland, D. H. P.; Blackwell, R. J.

    1975-01-01

    Relationships between LANDSAT-1 multispectral scanner (MSS) data and the trophic status of a group of lakes in the north-northeastern part of the United States were studied by predicting the magnitudes of two trophic state indicators, estimating lake position on a multivariate trophic scale, and automatically classifying lakes according to their trophic state. Initially, the principal component ordination was employed with 100 lakes. MSS data for some 20 lakes was then extracted from computer-compatible tapes (CCT) using a binary marking technique. The output was in the form of descriptive statistics and photographic concatenations. Color ratios were incorporated into regression models for the prediction of Secchi disc transparency, chlorophyll a, and lake position on the tropic scale. Results indicate that the LANDSAT-1 system, although handicapped by low spectral and spatial resolutions as well as excessive cloud cover, can be used as a supplemental data source in lake survey programs.

  17. 46 CFR 11.448 - Service requirements for mate of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... steam or motor vessels of not more than 500 gross tons. 11.448 Section 11.448 Shipping COAST GUARD... steam or motor vessels of not more than 500 gross tons. The minimum service required to qualify an applicant for an endorsement as mate of Great Lakes and inland steam or motor vessels of not more than...

  18. 46 CFR 11.448 - Service requirements for mate of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... steam or motor vessels of not more than 500 gross tons. 11.448 Section 11.448 Shipping COAST GUARD... steam or motor vessels of not more than 500 gross tons. The minimum service required to qualify an applicant for an endorsement as mate of Great Lakes and inland steam or motor vessels of not more than...

  19. 46 CFR 11.448 - Service requirements for mate of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... steam or motor vessels of not more than 500 gross tons. 11.448 Section 11.448 Shipping COAST GUARD... steam or motor vessels of not more than 500 gross tons. The minimum service required to qualify an applicant for an endorsement as mate of Great Lakes and inland steam or motor vessels of not more than...

  20. 46 CFR 11.448 - Service requirements for mate of Great Lakes and inland steam or motor vessels of not more than...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... steam or motor vessels of not more than 500 gross tons. 11.448 Section 11.448 Shipping COAST GUARD... steam or motor vessels of not more than 500 gross tons. The minimum service required to qualify an applicant for an endorsement as mate of Great Lakes and inland steam or motor vessels of not more than...

  1. Utilization of ERTS-1 data to monitor and classify eutrophication of inland lakes

    NASA Technical Reports Server (NTRS)

    Rogers, R. H.; Smith, V. E. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Significant findings are: (1) one-acre lakes and one-acre islands are detectable; (2)removal of atmospheric parameters derived from RPMI measurements show test lakes to have reflectances of 3.1 to 5.5% in band 4 and 0.3 to 2.3% in band 5; (3) failure to remove reflectance caused by atmosphere results in errors up to 500% in computing lake reflectance from ERTS-1 data; (4) in band 4, up to seven reflectance levels were observed in test lakes; (5) reflectance patterns have been displayed on a color-coded TV monitor and on computer-generated gray scales; (6) deep and shallow water can be separated by a trained photointerpreter and automatic machine processing, with estimates of water depth possible in some cases; (7) RPMI provides direct spectral signature measurements of lakes and lake features such as algal scums and floating plants; (8) a method is reported for obtaining lake color, as estimated by Forel-Ule standards, from ERTS-1 data; (9) a strong correlation between browner water color, diminishing water transparency; and (10) classifying lake eutrophication by observation of surface scums or macrophytes in shallow water seems straightforward.

  2. Utilization of ERTS-1 data to monitor and classify eutrophication of inland lakes

    NASA Technical Reports Server (NTRS)

    Chase, P. E.; Smith, V. E. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Significant findings are: (1) one acre lakes and one acre islands are detectable; (2) circular lakes of 7.5 acres and greater reach full density; (3) long channels 100 ft wide are detectable; (4) orientation of lakes is independent of scan direction; (5) lake features are observable in enlargements of CCT imagery produced in the Bendix Earth Resources Data Center; and (6) a decision surface water outline map is presented that was produced from ERTS-1 CCT. A water color literature review, baseline water quality data of the test lakes, and a discussion of geometric corrections of the CCT decision water surface outline map are also presented.

  3. Denitrification in a binary culture and thiocyanate metabolism in Thiohalophilus thiocyanoxidans gen. nov. sp. nov. - a moderately halophilic chemolithoautotrophic sulfur-oxidizing Gammaproteobacterium from hypersaline lakes.

    PubMed

    Sorokin, Dimitry Y; Tourova, Tatjana P; Bezsoudnova, Ekatherina Y; Pol, Arjan; Muyzer, Gerard

    2007-06-01

    Anaerobic enrichment culture with thiocyanate as electron donor and nitrate as electron acceptor at 2 M NaCl inoculated with a mixture of sediments from hypersaline lakes in Kulunda Steppe (Altai, Russia) resulted in a selection of a binary consortium of moderately halophilic, obligately chemolithoautotrophic sulfur-oxidizing bacteria (SOB) capable of complete denitrification of nitrate with thiosulfate as the electron donor. One consortium member, strain HRhD 3sp, was isolated into pure culture with nitrate and thiosulfate using a density gradient. This strain was responsible for the reduction of nitrate to nitrite in the consortium, while a second strain, HRhD 2, isolated under microoxic conditions with thiosulfate as substrate, was capable of anaerobic growth with nitrite and thiosulfate. Nitrite, either as substrate or as product, was already toxic at very low concentrations for both strains. As a result, optimal growth under anaerobic conditions could only be achieved within the consortium. On the basis of phylogenetic analysis, both organisms were identified as new lineages within the Gammaproteobacteria. As well as thiosulfate, strain HRhD 2 can also use thiocyanate as electron donor, representing a first halophilic SOB capable of growth with thiocyanate at 2-4 M NaCl. Product and enzymatic analysis identified the "carbonyl sulfide (COS) pathway" of primary thiocyanate degradation in this new species. On the basis of phenotypic and genetic analysis, strain HRhD 2 is proposed to be assigned to a new genus and species Thiohalophilus thiocyanoxidans.

  4. Novel and unexpected prokaryotic diversity in water and sediments of the alkaline, hypersaline lakes of the Wadi An Natrun, Egypt.

    PubMed

    Mesbah, Noha M; Abou-El-Ela, Soad H; Wiegel, Juergen

    2007-11-01

    The phylogenetic diversity of the bacterial and archaeal community in the water and sediments of three large lakes of the Wadi An Natrun was investigated using 16S rRNA clone libraries. The bacterial community was diverse: 769 clones formed 345 operational taxonomic units (OTUs) defined at 99% 16S rRNA sequence identity. The bacterial community in both the water and sediments of the lakes was dominated by clones affiliated with the low G + C Gram-type-positive group, alpha-proteobacteria, and Bacteroidetes, (11-39, 11-30, and 10-37% of OTUs observed, respectively), patterns that have been observed in previously described alkaline, athalassohaline systems. However, a relatively high proportion of Firmicutess-related clones in the water of the lakes and alpha-proteobacteria in the sediments was observed. The bacterial community composition of the water and sediment of the same lake and of different lakes was significantly different (p < 0.05). Operational taxonomic units related to the gamma-proteobacteria were more abundant in the sediment of Lake Fazda, whereas the sediment of Lake UmRisha was dominated by members of the delta-proteobacteria. The proportion of gamma-proteobacterial and Bacteroidetes-affiliated OTUs were predominant in the water of Lake UmRisha and differed significantly from other lake waters (chi-squared analysis, p < or = 0.01). The more oxygenated and dilute nature of Lake Hamra was reflected in its microbial community composition, with the abundance of Bacillales sequences in the water, the absence of Halanaerobiales, Clostridiales, and Archaea in the water, and the presence of representatives of more phyla such as the Actinobacteria, Spirochaetes, and Verrucomicrobia. The archaeal community composition appeared less diverse: 589 clones resulted in 198 OTUs defined at 99% 16S rRNA sequence identity, and all sequences fell into the phylum Euryarchaeota. Phylogenetic analysis showed that many of the sequences were distantly related (83-90% 16S r

  5. EVALUATING PERTUBATIONS AND DEVELOPING RESTORATION STRATEGIES FOR INLAND WETLANDS IN THE GREAT LAKES BASIN

    EPA Science Inventory

    Wetland coverage and type distributions vary systematically by ecoregion across the Great Lakes Basin. Land use and subsequent changes in wetland type distributions also vary among ecoregions. Incidence of wetland disturbance varies significantly within ecoregions but tends to i...

  6. EVALUATING PERTUBATIONS AND DEVELOPING RESTORATION STRATEGIES FOR INLAND WETLANDS IN THE GREAT LAKES BASIN

    EPA Science Inventory

    Wetland coverage and type distributions vary systematically by ecoregion across the Great Lakes Basin. Land use and subsequent changes in wetland type distributions also vary among ecoregions. Incidence of wetland disturbance varies significantly within ecoregions but tends to i...

  7. Automatic classification of eutrophication of inland lakes from spacecraft data. [Oakland County, Michigan

    NASA Technical Reports Server (NTRS)

    Rogers, R. H. (Principal Investigator); Reed, L. E.; Shah, N. J.; Smith, V. E.

    1974-01-01

    The author has identified the following significant results. Spacecraft data and computer techniques can be used to rapidly map and store onto digital tapes watershed land use information. Software is now available by which this land use information can be rapidly and economically extracted from the tapes and related to coliform counts and other lake contaminants (e.g. phosphorus). These tools are basic elements for determining those land use factors and sources of nutrients that accelerate eutrophication in lakes and reservoirs.

  8. Total- and methyl-mercury concentrations and methylation rates across the freshwater to hypersaline continuum of the Great Salt Lake, Utah, USA

    USGS Publications Warehouse

    Johnson, William P.; Swanson, Neil; Black, Brooks; Rudd, Abigail; Carling, Gregory; Fernandez, Diego P.; Luft, John; Van Leeuwen, Jim; Marvin-DiPasquale, Mark C.

    2015-01-01

    We examined mercury (Hg) speciation in water and sediment of the Great Salt Lake and surrounding wetlands, a locale spanning fresh to hypersaline and oxic to anoxic conditions, in order to test the hypothesis that spatial and temporal variations in Hg concentration and methylation rates correspond to observed spatial and temporal trends in Hg burdens previously reported in biota. Water column, sediment, and pore water concentrations of methylmercury (MeHg) and total mercury (THg), as well as related aquatic chemical parameters were examined. Inorganic Hg(II)-methylation rates were determined in selected water column and sediment subsamples spiked with inorganic divalent mercury (204Hg(II)). Net production of Me204Hg was expressed as apparent first-order rate constants for methylation (kmeth), which were also expanded to MeHg production potential (MPP) rates via combination with tin reducible ‘reactive’ Hg(II) (Hg(II)R) as a proxy for bioavailable Hg(II). Notable findings include: 1) elevated Hg concentrations previously reported in birds and brine flies were spatially proximal to the measured highest MeHg concentrations, the latter occurring in the anoxic deep brine layer (DBL) of the Great Salt Lake; 2) timing of reduced Hg(II)-methylation rates in the DBL (according to both kmeth and MPP) coincides with reduced Hg burdens among aquatic invertebrates (brine shrimp and brine flies) that act as potential vectors of Hg propagation to the terrestrial ecosystem; 3) values ofkmeth were found to fall within the range reported by other studies; and 4) MPP rates were on the lower end of the range reported in methodologically comparable studies, suggesting the possibility that elevated MeHg in the anoxic deep brine layer results from its accumulation and persistence in this quasi-isolated environment, due to the absence of light (restricting abiotic photo demethylation) and/or minimal microbiological demethylation.

  9. Total- and methyl-mercury concentrations and methylation rates across the freshwater to hypersaline continuum of the Great Salt Lake, Utah, USA.

    PubMed

    Johnson, William P; Swanson, Neil; Black, Brooks; Rudd, Abigail; Carling, Greg; Fernandez, Diego P; Luft, John; Van Leeuwen, Jim; Marvin-DiPasquale, Mark

    2015-04-01

    We examined mercury (Hg) speciation in water and sediment of the Great Salt Lake and surrounding wetlands, a locale spanning fresh to hypersaline and oxic to anoxic conditions, in order to test the hypothesis that spatial and temporal variations in Hg concentration and methylation rates correspond to observed spatial and temporal trends in Hg burdens previously reported in biota. Water column, sediment, and pore water concentrations of methylmercury (MeHg) and total mercury (THg), as well as related aquatic chemical parameters were examined. Inorganic Hg(II)-methylation rates were determined in selected water column and sediment subsamples spiked with inorganic divalent mercury (204Hg(II)). Net production of Me204Hg was expressed as apparent first-order rate constants for methylation (kmeth), which were also expanded to MeHg production potential (MPP) rates via combination with tin reducible 'reactive' Hg(II) (Hg(II)R) as a proxy for bioavailable Hg(II). Notable findings include: 1) elevated Hg concentrations previously reported in birds and brine flies were spatially proximal to the measured highest MeHg concentrations, the latter occurring in the anoxic deep brine layer (DBL) of the Great Salt Lake; 2) timing of reduced Hg(II)-methylation rates in the DBL (according to both kmeth and MPP) coincides with reduced Hg burdens among aquatic invertebrates (brine shrimp and brine flies) that act as potential vectors of Hg propagation to the terrestrial ecosystem; 3) values of kmeth were found to fall within the range reported by other studies; and 4) MPP rates were on the lower end of the range reported in methodologically comparable studies, suggesting the possibility that elevated MeHg in the anoxic deep brine layer results from its accumulation and persistence in this quasi-isolated environment, due to the absence of light (restricting abiotic photo demethylation) and/or minimal microbiological demethylation.

  10. Archaeal and bacterial communities respond differently to environmental gradients in anoxic sediments of a California hypersaline lake, the Salton Sea.

    PubMed

    Swan, Brandon K; Ehrhardt, Christopher J; Reifel, Kristen M; Moreno, Lilliana I; Valentine, David L

    2010-02-01

    Sulfidic, anoxic sediments of the moderately hypersaline Salton Sea contain gradients in salinity and carbon that potentially structure the sedimentary microbial community. We investigated the abundance, community structure, and diversity of Bacteria and Archaea along these gradients to further distinguish the ecologies of these domains outside their established physiological range. Quantitative PCR was used to enumerate 16S rRNA gene abundances of Bacteria, Archaea, and Crenarchaeota. Community structure and diversity were evaluated by terminal restriction fragment length polymorphism (T-RFLP), quantitative analysis of gene (16S rRNA) frequencies of dominant microorganisms, and cloning and sequencing of 16S rRNA. Archaea were numerically dominant at all depths and exhibited a lesser response to environmental gradients than that of Bacteria. The relative abundance of Crenarchaeota was low (0.4 to 22%) at all depths but increased with decreased carbon content and increased salinity. Salinity structured the bacterial community but exerted no significant control on archaeal community structure, which was weakly correlated with total carbon. Partial sequencing of archaeal 16S rRNA genes retrieved from three sediment depths revealed diverse communities of Euryarchaeota and Crenarchaeota, many of which were affiliated with groups previously described from marine sediments. The abundance of these groups across all depths suggests that many putative marine archaeal groups can tolerate elevated salinity (5.0 to 11.8% [wt/vol]) and persist under the anaerobic conditions present in Salton Sea sediments. The differential response of archaeal and bacterial communities to salinity and carbon patterns is consistent with the hypothesis that adaptations to energy stress and availability distinguish the ecologies of these domains.

  11. Halanaerobium sehlinense sp. nov., an extremely halophilic, fermentative, strictly anaerobic bacterium from sediments of the hypersaline lake Sehline Sebkha.

    PubMed

    Abdeljabbar, Hedi; Cayol, Jean-Luc; Ben Hania, Wajdi; Boudabous, Abdellatif; Sadfi, Najla; Fardeau, Marie-Laure

    2013-06-01

    A strictly anaerobic, extremely halophilic, Gram-positive, rod-shaped bacterium was isolated from the hypersaline (>20% NaCl) surface sediments of Sehline Sebkha in Tunisia. The strain, designated 1Sehel(T), was strictly halophilic and proliferated at NaCl concentrations of between 5% and 30% (saturation), with optimal growth at 20% NaCl. Strain 1Sehel(T) was non-spore-forming, non-motile, appearing singly or in pairs, or occasionally as long chains and measured 0.5-0.8 µm by 3-10 µm. Strain 1Sehel(T) grew optimally at pH values of 7.4 but had a very broad pH range for growth (pH 5.2-9.4). It grew at temperatures between 20 and 50 °C with an optimum at 43 °C. Strain 1Sehel(T) required yeast extract for growth. The isolate fermented glucose, galactose, fructose, glycerol, mannose, maltose, ribose, pyruvate and sucrose. The fermentation products from glucose utilization were lactate, acetate, formate, ethanol, CO2 and H2. The G+C ratio of the DNA was 32.7 mol%. The major fatty acids were C15:1ω6c/7c, C16:1ω7c, C16:0 and C15:0. On the basis of phylogenetic and physiological properties, strain 1Sehel(T) (=DSM 25582(T)=JCM 18213(T)) is proposed as the type strain of Halanaerobium sehlinense sp. nov., within the family Halanaerobiaceae.

  12. Utilization of ERTS-1 data to monitor and classify eutrophication of inland lakes

    NASA Technical Reports Server (NTRS)

    Chase, P. E. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Bands 6 and 7 have fine structure as obtained by proper selection of digital levels in processing the CCT's. This is contrary to the imagery density received. This means that the small lakes can be classified in IR for different types of water masses. At least four distinct water masses have been determined for test lakes. They are shoreline, shallow water, and two deep waters. One deep water is patchy and presents difficulty in training set selection. The excellent weather and a completely successful field test form a significant happening. It required 12 orbits over the test area before perfect weather occurred.

  13. High prevalence of buccal ulcerations in largemouth bass, Micropterus salmoides (Centrarchidae) from Michigan inland lakes associated with Myzobdella lugubris Leidy 1851 (Annelida: Hirudinea)

    PubMed Central

    Faisal, M.; Schulz, C.; Eissa, A.; Whelan, G.

    2011-01-01

    Widespread mouth ulcerations were observed in largemouth bass collected from eight inland lakes in the Lower Peninsula of Michigan during the summer months of 2002 and 2003. These ulcerations were associated with, and most likely caused by, leech parasitism. Through the use of morphological dichotomous keys, it was determined that all leeches collected are of one species: Myzobdella lugubris. Among the eight lakes examined, Lake Orion and Devils Lake had the highest prevalence of leech parasitism (34% and 29%, respectively) and mouth ulcerations (53% and 68%, respectively). Statistical analyses demonstrated that leech and ulcer prevalence varied significantly from one lake to the other. Additionally, it was determined that the relationship between the prevalence of ulcers and the prevalence of leech attachment is significant, indicating that leech parasitism is most likely the cause of ulceration. The ulcers exhibited deep hemorrhagic centers and raised irregular edges. Affected areas lost their epithelial lining and submucosa, with masses of bacteria colonizing the damaged tissues. Since largemouth bass is a popular global sportfish and critical to the food web of inland lakes, there are concerns that the presence of leeches, damaged buccal mucosa, and general unsightliness may negatively affect this important sportfishery. PMID:21395209

  14. Carbonate Biogenic Structures in Storrs Lake, Bahamas

    NASA Technical Reports Server (NTRS)

    Byrne, Monica; Morris, Penny A.; Wentworth, Susan J.; Brigmon, Robin L.; McKay, David S.

    2001-01-01

    Storr's Lake, an inland hypersaline lake on San Salvador Island, Bahamas, contains calcium carbonate-rich lithified mats of filamentous microorganisms, diatoms, associated photosynthetic and chemotrophic bacteria, and trapped sediment. In addition, 16S rRNA analysis indicates the presence of five sulfur-reducing genera of bacteria. These microbes are potential modern-day analogs to some ancient stromatolitic structures. The goals of this study are to identify unique compositional and biogenic features, possibly correlating some of these with some of the sulfate-reducing bacteria. Additional information is contained in the original extended abstract.

  15. Carbonate Biogenic Structures in Storrs Lake, Bahamas

    NASA Technical Reports Server (NTRS)

    Byrne, Monica; Morris, Penny A.; Wentworth, Susan J.; Brigmon, Robin L.; McKay, David S.

    2001-01-01

    Storr's Lake, an inland hypersaline lake on San Salvador Island, Bahamas, contains calcium carbonate-rich lithified mats of filamentous microorganisms, diatoms, associated photosynthetic and chemotrophic bacteria, and trapped sediment. In addition, 16S rRNA analysis indicates the presence of five sulfur-reducing genera of bacteria. These microbes are potential modern-day analogs to some ancient stromatolitic structures. The goals of this study are to identify unique compositional and biogenic features, possibly correlating some of these with some of the sulfate-reducing bacteria. Additional information is contained in the original extended abstract.

  16. Immune factors and fatty acid composition in human milk from river/lake, coastal and inland regions of China.

    PubMed

    Urwin, Heidi J; Zhang, Jian; Gao, Yixiong; Wang, Chunrong; Li, Lixiang; Song, Pengkun; Man, Qingqing; Meng, Liping; Frøyland, Livar; Miles, Elizabeth A; Calder, Philip C; Yaqoob, Parveen

    2013-06-01

    Breast milk fatty acid composition may be affected by the maternal diet during gestation and lactation. The influence of dietary and breastmilk fatty acids on breast milk immune factors is poorly defined. We determined the fatty acid composition and immune factor concentrations of breast milk from women residing in river/lake, coastal and inland regions of China, which differ in their consumption of lean fish and oily fish. Breast milk samples were collected on days 3–5 (colostrum), 14 and 28 post-partum (PP) and analysed for soluble CD14 (sCD14), transforming growth factor (TGF)-b1, TGF-b2, secretory IgA (sIgA) and fatty acids. The fatty acid composition of breast milk differed between the regions and with time PP. The concentrations of all four immune factors in breast milk decreased over time, with sCD14, sIgA and TGF-b1 being highest in the colostrum in the river and lake region. Breast milk DHA and arachidonic acid (AA) were positively associated, and g-linolenic acid and EPA negatively associated, with the concentrations of each of the four immune factors. In conclusion, breast milk fatty acids and immune factors differ between the regions in China characterised by different patterns of fish consumption and change during the course of lactation. A higher breast milk DHA and AA concentration is associated with higher concentrations of immune factors in breast milk, suggesting a role for these fatty acids in promoting gastrointestinal and immune maturation of the infant.

  17. Depth Distribution of Archaeal Diversity and Community Composition Across Steep Geochemical Gradients in Anoxic Sediments of a Hypersaline Lake

    NASA Astrophysics Data System (ADS)

    Swan, B. K.; Valentine, D. L.

    2006-12-01

    Patterns in Archaeal diversity and community composition were investigated in the anoxic sediments of the Salton Sea, California's largest lake. The sediments of this lake contain strong gradients in salinity and organic carbon, which provide a natural setting to examine the influence of these gradients on Archaeal communities. Measurements of sediment and porewater geochemistry and Archaeal diversity were made within the top 33cm of sediment. Porewater sulfate and total salinity, organic carbon and mineral content of the bulk sediment were measured at 1-cm intervals; Archaeal diversity was determined at 2-cm intervals using T-RFLP analysis to identify unique phylotypes. To examine Archaeal community composition 16S rDNA clone libraries were constructed at three depth intervals across the gradients. Between 4-23 Archaeal phylotypes were identified across the gradients, and the number of phylotypes was negatively correlated with organic carbon content. 16S rDNA clone libraries revealed the presence of members within the Euryarchaeota and Crenarchaeota groups. The biogeochemical role of these uncultured anaerobic Archaea remains unknown, but we hypothesize that the high-salt and low organic carbon conditions that exist in the deeper sediments provide an environmental niche that Archaea exploit to compete with the Bacterial community.

  18. Comparative functional ultrastructure of two hypersaline submerged cyanobacterial mats - Guerrero Negro, Baja California Sur, Mexico, and Solar Lake, Sinai, Egypt

    NASA Technical Reports Server (NTRS)

    D'Amelio, Elisa D'antoni; Des Marais, David J.; Cohen, Jehuda

    1989-01-01

    The ultrastructure of the submerged microbial mat from the Solar Lake (SL), Egypt, was compared to that of samples from the Guerrero Negro (GN), Mexico, salt pans. The locations and distributions of the main organisms were determined light microscopy, and the corresponding ultrathin sections were examined under TEM; chemical microprofile analyses were carried out on the day of sampling for microscopic studies. Both communities were found to be dominated by Microleus chthonoplastes, although several morphological species found in the GN mat were absent from the SL mat, including the Tropica nigra and the 'big' Microleus chthonoplastes component. The chemical microprofiles of oxygen, sulfide, pH, and the oxygenic photosynthesis in the two mats were virtually identical. In both mats, the photic zone was restricted to the upper 800 microns of the mat, and oxygenic photosynthesis was detected down to 600 microns.

  19. Comparative functional ultrastructure of two hypersaline submerged cyanobacterial mats - Guerrero Negro, Baja California Sur, Mexico, and Solar Lake, Sinai, Egypt

    NASA Technical Reports Server (NTRS)

    D'Amelio, Elisa D'antoni; Des Marais, David J.; Cohen, Jehuda

    1989-01-01

    The ultrastructure of the submerged microbial mat from the Solar Lake (SL), Egypt, was compared to that of samples from the Guerrero Negro (GN), Mexico, salt pans. The locations and distributions of the main organisms were determined light microscopy, and the corresponding ultrathin sections were examined under TEM; chemical microprofile analyses were carried out on the day of sampling for microscopic studies. Both communities were found to be dominated by Microleus chthonoplastes, although several morphological species found in the GN mat were absent from the SL mat, including the Tropica nigra and the 'big' Microleus chthonoplastes component. The chemical microprofiles of oxygen, sulfide, pH, and the oxygenic photosynthesis in the two mats were virtually identical. In both mats, the photic zone was restricted to the upper 800 microns of the mat, and oxygenic photosynthesis was detected down to 600 microns.

  20. Geophysical, isotopic, and hydrogeochemical tools to identify potential impacts on coastal groundwater resources from Urmia hypersaline Lake, NW Iran.

    PubMed

    Amiri, Vahab; Nakhaei, Mohammad; Lak, Razyeh; Kholghi, Majid

    2016-08-01

    Measurements of major ions, trace elements, water-stable isotopes, and geophysical soundings were made to examine the interaction between Urmia Aquifer (UA) and Urmia Lake (UL), northwest Iran. The poor correlation between sampling depth and Cl(-) concentrations indicated that the position of freshwater-saltwater interface is not uniformly distributed in the study area, and this was attributed to aquifer heterogeneities. The targeted coastal wells showed B/Cl and Br/Cl molar ratios in the range of 0.0022-2.43 and 0.00032-0.28, respectively. The base-exchange index (BEI) and saturation index (SI) calculations showed that the salinization process followed by cation-exchange reactions mainly controls changes in the chemical composition of groundwater. All groundwater samples are depleted with respect to δ(18)O (-11.71 to -9.4 ‰) and δD (-66.26 to -48.41 ‰). The δ(18)O and δD isotope ratios for surface and groundwater had a similar range and showed high deuterium excess (d-excess) (21.11 to 31.16 ‰). The high d-excess in water samples is because of incoming vapors from the UL mixed with an evaporated moisture flux from the Urmia mainland and incoming vapors from the west (i.e., Mediterranean Sea). Some saline samples with low B/Cl and Br/Cl ratios had depleted δ(18)O and δD. In this case, due to freshwater flushing, the drilled wells in the coastal playas and salty sediments could have more depleted isotopes, more Cl(-), and consequently smaller B/Cl and Br/Cl ratios. Moreover, the results of hydrochemical facies evolution (HFE) diagram showed that because of the existence fine-grained sediments saturated with high density saltwater in the coastal areas that act as a natural barrier, increasing the groundwater exploitation leads to movement of freshwaters from recharge zones in the western mountains not saltwater from UL. The highly permeable sediments at the junction of the rivers to the lake are characterized by low hydraulic gradient and high

  1. Halorientalis brevis sp. nov., Isolated from an Inland Salt Lake of China.

    PubMed

    Yuan, Pan-Pan; Yin, Shuai; Han, Dong; Zhang, Wen-Jiao; Cui, Heng-Lin

    2015-09-01

    Halophilic archaeal strain YC89(T) was isolated from Yuncheng salt lake in Shanxi, China. Cells from strain YC89(T) were short rods, lysed in distilled water, stained Gram-negative and formed red-pigmented colonies on agar plate. Strain YC89(T) was able to grow at 25-50°C (optimum 37°C), at 1.4-4.8 M NaCl (optimum 2.6-3.1 M), at 0-1.0 M MgCl2 (optimum 0.3 M) and at pH 6.0-9.5 (optimum pH 7.5). The major polar lipids are phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, sulfated mannosyl glucosyl diether and two unknown glycolipids. 16S rRNA gene analysis revealed that strain YC89(T) was phylogenetically related to Halorientalis persicus D108(T) (95.6% nucleotide identity) and H. regularis TNN28(T) (95.3% nucleotide identity). The rpoB' gene similarities between strain YC89(T) and H. persicus IBRC-M 10043(T) and H. regularis TNN28(T) were 88.1 and 88.0%, respectively. The DNA G+C content of strain YC89(T) was determined to be 61.3 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain YC89(T) (=CGMCC 1.12125(T) = JCM 18366(T)) represents a new species of Halorientalis, for which the name H. brevis sp. nov. is proposed.

  2. Eco-morphological differentiation in Lake Magadi tilapia, an extremophile cichlid fish living in hot, alkaline and hypersaline lakes in East Africa.

    PubMed

    Kavembe, Geraldine D; Kautt, Andreas F; Machado-Schiaffino, Gonzalo; Meyer, Axel

    2016-04-01

    Ecological diversification through divergent selection is thought to be a major force during the process of adaptive radiations. However, the large sizes and complexity of most radiations such as those of the cichlids in the African Great Lakes make it impossible to infer the exact evolutionary history of any population divergence event. The genus Alcolapia, a small cichlid lineage endemic to Lakes Magadi and Natron in East Africa, exhibits phenotypes similar to some of those found in cichlids of the radiations of the African Great Lakes. The simplicity within Alcolapia makes it an excellent model system to investigate ecological diversification and speciation. We used an integrated approach including population genomics based on RAD-seq data, geometric morphometrics and stable isotope analyses to investigate the eco-morphological diversification of tilapia in Lake Magadi and its satellite lake Little Magadi. Additionally, we reconstructed the demographic history of the species using coalescent simulations based on the joint site frequency spectrum. The population in Little Magadi has a characteristically upturned mouth--possibly an adaptation to feeding on prey from the water surface. Eco-morphological differences between populations within Lake Magadi are more subtle, but are consistent with known ecological differences between its lagoons such as high concentrations of nitrogen attributable to extensive guano deposits in Rest of Magadi relative to Fish Springs Lagoon. All populations diverged simultaneously only about 1100 generations ago. Differences in levels of gene flow between populations and the effective population sizes have likely resulted in the inferred heterogeneous patterns of genome-wide differentiation.

  3. [The new bacteriochlorophyll a-containing bacterium Roseinatronobacter monicus sp. nov. from the hypersaline soda Mono Lake (California, United States)].

    PubMed

    Boldareva, E N; Briantseva, I A; Tsapin, A; Nelson, K; Sorokin, D Iu; Turova, T P; Boĭchenko, V A; Stadnichuk, I N; Gorlenko, V M

    2007-01-01

    Two strains of pink-colored aerobic bacteriochlorophyll a-containing bacteria were isolated from aerobic (strain ROS 10) and anaerobic (strain ROS 35) zones of the water column of Mono Lake (California, United States). Cells of the bacteria were nonmotile oval gram-negative rods multiplying by binary fission by means of a constriction. No intracellular membranes were detected. Polyphosphates and poly-1-hydroxybutyric acid were the storage compounds. Pigments were represented by bacteriochlorophyll a and carotenoids of the spheroidene series. The strains were obligately aerobic, mesophilic (temperature optimum of 25-30 degrees C), alkaliphilic (pH optimum of 8.5-9.5), and halophilic (optimal NaCl concentration of 40-60 g/l). They were obligately heterotrophic and grew aerobically in the dark and in the light. Respiration was inhibited by light at wavelengths corresponding to the absorption of the cellular pigments. The substrate utilization spectra were strain-specific. In the course of organotrophic growth, the bacteria could oxidize thiosulfate to sulfate; sulfide and polysulfide could also be oxidized. The DNA G+C content was 59.4 mol % in strain ROS 10 and 59 mol % in strain ROS 35. In their phenotypic properties, the new strains were close but not identical to the alkaliphilic bacterium Roseinatronobacter thiooxidans. The distinctions in the nucleotide sequences of the 16S rRNA genes (2%) and low DNA-DNA hybridization level with Rna. thiooxidans (22-25%) allow the new strains to be assigned to a new species of the genus Roseinatronobacter, Roseinatronobacter monicus sp. nov.

  4. Inland capture fisheries.

    PubMed

    Welcomme, Robin L; Cowx, Ian G; Coates, David; Béné, Christophe; Funge-Smith, Simon; Halls, Ashley; Lorenzen, Kai

    2010-09-27

    The reported annual yield from inland capture fisheries in 2008 was over 10 million tonnes, although real catches are probably considerably higher than this. Inland fisheries are extremely complex, and in many cases poorly understood. The numerous water bodies and small rivers are inhabited by a wide range of species and several types of fisher community with diversified livelihood strategies for whom inland fisheries are extremely important. Many drivers affect the fisheries, including internal fisheries management practices. There are also many drivers from outside the fishery that influence the state and functioning of the environment as well as the social and economic framework within which the fishery is pursued. The drivers affecting the various types of inland water, rivers, lakes, reservoirs and wetlands may differ, particularly with regard to ecosystem function. Many of these depend on land-use practices and demand for water which conflict with the sustainability of the fishery. Climate change is also exacerbating many of these factors. The future of inland fisheries varies between continents. In Asia and Africa the resources are very intensely exploited and there is probably little room for expansion; it is here that resources are most at risk. Inland fisheries are less heavily exploited in South and Central America, and in the North and South temperate zones inland fisheries are mostly oriented to recreation rather than food production.

  5. Inland capture fisheries

    PubMed Central

    Welcomme, Robin L.; Cowx, Ian G.; Coates, David; Béné, Christophe; Funge-Smith, Simon; Halls, Ashley; Lorenzen, Kai

    2010-01-01

    The reported annual yield from inland capture fisheries in 2008 was over 10 million tonnes, although real catches are probably considerably higher than this. Inland fisheries are extremely complex, and in many cases poorly understood. The numerous water bodies and small rivers are inhabited by a wide range of species and several types of fisher community with diversified livelihood strategies for whom inland fisheries are extremely important. Many drivers affect the fisheries, including internal fisheries management practices. There are also many drivers from outside the fishery that influence the state and functioning of the environment as well as the social and economic framework within which the fishery is pursued. The drivers affecting the various types of inland water, rivers, lakes, reservoirs and wetlands may differ, particularly with regard to ecosystem function. Many of these depend on land-use practices and demand for water which conflict with the sustainability of the fishery. Climate change is also exacerbating many of these factors. The future of inland fisheries varies between continents. In Asia and Africa the resources are very intensely exploited and there is probably little room for expansion; it is here that resources are most at risk. Inland fisheries are less heavily exploited in South and Central America, and in the North and South temperate zones inland fisheries are mostly oriented to recreation rather than food production. PMID:20713391

  6. Inland Water Temperature Trends

    NASA Astrophysics Data System (ADS)

    Hook, S. J.; Lenters, J. D.; Schladow, G.; Healey, N.

    2016-12-01

    We are using thermal infrared satellite data in conjunction with in situ measurements to produce water temperatures for all the large inland water bodies in North America and the rest of the world for potential use as climate indicator. Recent studies have revealed significant warming of inland waters throughout the world. The observed rate of warming is - in many cases - greater than that of the ambient air temperature. These rapid, unprecedented changes in inland water temperatures have profound implications for lake hydrodynamics, productivity, and biotic communities. Scientists are just beginning to understand the global extent, regional patterns, physical mechanisms, and ecological consequences of lake warming. As part of our earlier studies we have collected thermal infrared satellite data from those satellite sensors that provide long-term and frequent spaceborne thermal infrared measurements of inland waters including ATSR, AVHRR, and MODIS and used these to examine trends in water surface temperature for approximately 169 of the largest inland water bodies in the world. We are now extending this work to generate temperature time-series of all North American inland water bodies that are sufficiently large to be studied using 1km resolution satellite data for the last 3 decades, approximately 268 lakes. These data are then being related to changes in the surface air temperature and compared with regional trends in water surface temperature derived from CMIP5/IPCC model simulations/projections to better predict future temperature changes. We will discuss the available datasets and processing methodologies together with the patterns they reveal and implications for ecosystem change in inland waters.

  7. Brazilian inland water bio-optical dataset to support carbon budget studies in reservoirs as well as anthropogenic impacts in Amazon floodplain lakes: Preliminary results

    NASA Astrophysics Data System (ADS)

    Barbosa, C.; Novo, E.; Ferreira, R.; Carvalho, L.; Cairo, C.; Lopes, F.; Stech, J.; Alcantara, E.

    2015-04-01

    This work presents ongoing efforts and preliminary results for building a dataset that represents the first and most comprehensive bio-optical information available on Brazilian inland waters to support the development of remote sensing algorithms for monitoring aquatic systems. From 2012 to 2014 optical and limnological data was gathered along thirteen field campaigns in five Brazilian reservoirs, in an irrigation and domestic water supply reservoir located in semi-arid northeast of the country and in Amazonian floodplain lakes, thus covering the diversity of Brazilian inland waters. At each site 20 stations, on average, were sampled to acquire profiles of the following optical variables: absorption, attenuation, scattering, and backscattering coefficients and radiances/irradiances spectra above and in-water. Alongside these measurements, water samples were collected for determining concentrations of chlorophyll-a (Chl-a), Total Suspended Solid (TSS), Total Dissolved Carbon (TDC) and its organic/inorganic fractions, CDOM absorption, phytoplankton specific absorption [aph*] and Non-Algal Particles absorption [aNAP*]. Preliminary results show that Chl-a concentrations ranged from 0.6 to 243μg/L in reservoirs and 0.90 to 92μg/L in Amazonian lakes, while TSS concentrations ranged from 0.3 to 31mg/L in reservoirs and 0.5 to 162mg/L in Amazonian lakes. In situ beam attenuation coefficients ranged from 1.4 to 16m-1 in reservoirs and 12.5 to 38m-1 in Amazonian lakes, while diffuse attenuation coefficients of downwelling irradiance over the Photosynthetically Active Radiation (Kd(PAR)) extended from 0.35 to 4.5m-1 in reservoirs and 1.69 to 13.30m-1 in Amazonian lakes. Our research group is building this dataset anticipating future demands for algorithm validation regarding OLI/Landsat8 data and ESA Sentinel missions to be launched as of 2015.

  8. Developing a semi-analytical algorithm to estimate particulate organic carbon (POC) levels in inland eutrophic turbid water based on MERIS images: A case study of Lake Taihu

    NASA Astrophysics Data System (ADS)

    Lyu, Heng; Wang, Yannan; Jin, Qi; Shi, Lei; Li, Yunmei; Wang, Qiao

    2017-10-01

    Particulate organic carbon (POC) plays an important role in the carbon cycle in water due to its biological pump process. In the open ocean, algorithms can accurately estimate the surface POC concentration. However, no suitable POC-estimation algorithm based on MERIS bands is available for inland turbid eutrophic water. A total of 228 field samples were collected from Lake Taihu in different seasons between 2013 and 2015. At each site, the optical parameters and water quality were analyzed. Using in situ data, it was found that POC-estimation algorithms developed for the open ocean and coastal waters using remote sensing reflectance were not suitable for inland turbid eutrophic water. The organic suspended matter (OSM) concentration was found to be the best indicator of the POC concentration, and POC has an exponential relationship with the OSM concentration. Through an analysis of the POC concentration and optical parameters, it was found that the absorption peak of total suspended matter (TSM) at 665 nm was the optimum parameter to estimate POC. As a result, MERIS band 7, MERIS band 10 and MERIS band 12 were used to derive the absorption coefficient of TSM at 665 nm, and then, a semi-analytical algorithm was used to estimate the POC concentration for inland turbid eutrophic water. An accuracy assessment showed that the developed semi-analytical algorithm could be successfully applied with a MAPE of 31.82% and RMSE of 2.68 mg/L. The developed algorithm was successfully applied to a MERIS image, and two full-resolution MERIS images, acquired on August 13, 2010, and December 7, 2010, were used to map the POC spatial distribution in Lake Taihu in summer and winter.

  9. Response of Glacier and Lake Dynamics in Four Inland Basins to Climate Change at the Transition Zone between the Karakorum And Himalayas

    PubMed Central

    Li, Zhiguo; Fan, Kuangsheng; Tian, Lide; Shi, Benlin; Zhang, Shuhong; Zhang, Jingjing

    2015-01-01

    Inland glacier and lake dynamics on the Tibetan Plateau (TP) and its surroundings over recent decades are good indicators of climate change and have a significant impact on the local water supply and ecosystem. The glacier and lake changes in Karakoram are quite different from those of the Himalayas. The mechanisms of the complex and regionally heterogeneous behavior of the glacier and lake changes between the Karakorum and Himalayas are poorly understood. Based on satellite images and meteorological data of Shiquanhe, Hetian, and Yutian stations, we demonstrate that the overall retreat of glaciers and increase of lake area at the transition zone between the Karakoram and Himalayas (TKH) have occurred since 1968 in response to a significant global climate change. Glacial areas in the Songmuxi Co basin, Zepu Co basin, Mang Co basin and Unnamed Co decreased by -1.98 ± 0.02 km2, -5.39 ± 0.02 km2, -0.01 ± 0.02 km2, and -0.12 ± 0.02 km2 during the study period, corresponding to losses of -1.42%, -2.86%, -1.54%, and -1.57%, respectively. The lake area of the Songmuxi Co, Zepu Co, Mang Co and Unnamed Co increased by 7.57 ± 0.02 km2, 8.53 ± 0.02 km2, 1.35 ± 0.02 km2, and 0.53±0.02 km2, corresponding to growths of 30.22%, 7.55%, 11.39%, and 8.05%, respectively. Increases in temperature was the main reason for glacier retreat, whereas decreases in potential evapotranspiration of lakes, increases in precipitation, and increases in melt water from glaciers and frozen soil all contributed to lake area expansion. PMID:26699717

  10. Response of Glacier and Lake Dynamics in Four Inland Basins to Climate Change at the Transition Zone between the Karakorum And Himalayas.

    PubMed

    Li, Zhiguo; Fan, Kuangsheng; Tian, Lide; Shi, Benlin; Zhang, Shuhong; Zhang, Jingjing

    2015-01-01

    Inland glacier and lake dynamics on the Tibetan Plateau (TP) and its surroundings over recent decades are good indicators of climate change and have a significant impact on the local water supply and ecosystem. The glacier and lake changes in Karakoram are quite different from those of the Himalayas. The mechanisms of the complex and regionally heterogeneous behavior of the glacier and lake changes between the Karakorum and Himalayas are poorly understood. Based on satellite images and meteorological data of Shiquanhe, Hetian, and Yutian stations, we demonstrate that the overall retreat of glaciers and increase of lake area at the transition zone between the Karakoram and Himalayas (TKH) have occurred since 1968 in response to a significant global climate change. Glacial areas in the Songmuxi Co basin, Zepu Co basin, Mang Co basin and Unnamed Co decreased by -1.98 ± 0.02 km2, -5.39 ± 0.02 km2, -0.01 ± 0.02 km2, and -0.12 ± 0.02 km2 during the study period, corresponding to losses of -1.42%, -2.86%, -1.54%, and -1.57%, respectively. The lake area of the Songmuxi Co, Zepu Co, Mang Co and Unnamed Co increased by 7.57 ± 0.02 km2, 8.53 ± 0.02 km2, 1.35 ± 0.02 km2, and 0.53 ± 0.02 km2, corresponding to growths of 30.22%, 7.55%, 11.39%, and 8.05%, respectively. Increases in temperature was the main reason for glacier retreat, whereas decreases in potential evapotranspiration of lakes, increases in precipitation, and increases in melt water from glaciers and frozen soil all contributed to lake area expansion.

  11. Monitoring Inland Water Turbidity: Contribution of SPOT5 Take5 to Health Hazard Monitoring in West Africa (Bagre Lake, Burkina Faso)

    NASA Astrophysics Data System (ADS)

    Robert, Elodie; Grippa, Manuela; Kergoat, Laurent; Martinez, Jean-Michel; Pinet, Sylvain; Somdecoste, Tom; Gal, Laetitia

    2016-08-01

    Monitoring turbidity and Surface Suspended Sediment Concentration (SSSC) of inland waters in tropics is essential to assess human health risks, in particular the diarrheal disease risk. In this study, we explore the use of Spot5 time series acquired for the Spot5Take5 Program to monitor turbidity and SSSC on the Bagre Lake (Burkina Faso). Field measurements (turbidity, SSSC, radiometry) are used to evaluate different radiometric indices. The combination of the NIR with a visible band (R or G) is found to be the best suited to retrieve SSSC and turbidity from Spot5 images. Large differences between upstream and downstream areas of the lake are well capture by the Spot5 time series, with large difference in the seasonal maximum both for absolute values and timing. A large sediment transport is observed from upstream to downstream between June and September caused by surface runoff and erosion. The high turbidity values observed suggest that the associated health hazard is potentially high, especially at the beginning of the rainy season and in the upstream areas of the lake.

  12. A physico-chemical survey of inland lakes and saline ponds: Christmas Island (Kiritimati) and Washington (Teraina) Islands, Republic of Kiribati

    PubMed Central

    Saenger, Casey; Miller, Michael; Smittenberg, Rienk H; Sachs, Julian P

    2006-01-01

    The equatorial Pacific Ocean atoll islands of Kiritimati and Teraina encompass great physical, chemical and biological variability within extreme lacustrine environments. Surveys of lake chemistry and sediments revealed both intra- and inter-island variability. A survey of more than 100 lakes on Kiritimati found salinities from nearly fresh to 150 ppt with the highest values occurring within the isolated, inland portions of the island away from the influence of groundwater or extreme tides. Dissolved oxygen (DO) and pH values also showed considerable variability with a less regular spatial pattern, but were both generally inversely related to salinity. Series of lakes, progressively more isolated from marine communication, present a modern analog to the chemical and morphologic evolution of presently isolated basins. Sediments on both islands consist of interbedded red and green silt, possibly degraded bacterial mat, overlying white, mineralogenic silt precipitate. Variability may be indicative of shifts in climatological parameters such as the El Niño Southern Oscillation (ENSO) or the Pacific Intertropical Convergence Zone (ITCZ). PMID:16817958

  13. Chemical pollution in inland shallow lakes in the Mediterranean region (NW Spain): PAHs, insecticides and herbicides in water and sediments.

    PubMed

    Hijosa-Valsero, María; Bécares, Eloy; Fernández-Aláez, Camino; Fernández-Aláez, Margarita; Mayo, Rebeca; Jiménez, Juan José

    2016-02-15

    The possible effect of land uses and human-related geographic patterns (presence of roads and urban settlements) on chemical pollution was evaluated in the waters and sediments of fifty-three Mediterranean shallow lakes. The presence of fifty-nine pollutants (belonging to PAHs, insecticides and herbicides groups) was analysed in these lakes by GC-MS. The studied lakes had similar pollutant concentrations to other lakes worldwide. The distribution of the compounds between water and sediment compartments was strongly influenced by log K(ow) values (an average of 3.61 for compounds found in water and of 4.69 for compounds found in sediments). A multivariate analysis suggested that the concentration of PAHs in water could be related to agricultural activities and not related to local road traffic. When assessing nutrient levels in the lakes, it was observed that eutrophicated lakes [>300 μg L(-1) total phosphorus (TP)] appeared in areas affected by urban or industrial use (at least 2% urban use in a 1-km radius around the lake), whilst lakes with lower TP concentrations were placed in forest areas (60% of forest use in a 1-km radius); in addition, the aqueous concentrations of Σ(PAH) were lower in lakes with higher TP concentrations (>150 μg L(-1) TP), which could be related to the adsorption capacity of PAHs onto suspended matter which is present in mesotrophic and eutrophic lakes, thus being removed from the aqueous phase. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Hydrocarbon Biodegradation in Hypersaline Environments

    PubMed Central

    Ward, David M.; Brock, T. D.

    1978-01-01

    When mineral oil, hexadecane, and glutamate were added to natural samples of varying salinity (3.3 to 28.4%) from salt evaporation ponds and Great Salt Lake, Utah, rates of metabolism of these compounds decreased as salinity increased. Rate limitations did not appear to relate to low oxygen levels or to the availability of organic nutrients. Some oxidation of l-[U-14C]glutamic acid occurred even at extreme salinities, whereas oxidation of [1-14C]hexadecane was too low to be detected. Gas chromatographic examination of hexane-soluble components of tar samples from natural seeps at Rozel Point in Great Salt Lake demonstrated no evidence of biological oxidation of isoprenoid alkanes subject to degradation in normal environments. Some hexane-soluble components of the same tar were altered by incubation in a low-salinity enrichment culture inoculated with garden soil. Attempts to enrich for microorganisms in saline waters able to use mineral oil as a sole source of carbon and energy were successful below, but not above, about 20% salinity. This study strongly suggests a general reduction of metabolic rate at extreme salinities and raises doubt about the biodegradation of hydrocarbons in hypersaline environments. PMID:16345276

  15. Redfield Ratios in Inland Waters: Higher Biological Control of C:N:P Ratios in Tropical Semi-arid High Water Residence Time Lakes

    PubMed Central

    They, Ng H.; Amado, André M.; Cotner, James B.

    2017-01-01

    The canonical Redfield C:N:P ratio for algal biomass is often not achieved in inland waters due to higher C and N content and more variability when compared to the oceans. This has been attributed to much lower residence times and higher contributions of the watershed to the total organic matter pool of continental ecosystems. In this study we examined the effect of water residence times in low latitude lakes (in a gradient from humid to a semi-arid region) on seston elemental ratios in different size fractions. We used lake water specific conductivity as a proxy for residence time in a region of Eastern Brazil where there is a strong precipitation gradient. The C:P ratios decreased in the seston and bacterial size-fractions and increased in the dissolved fraction with increasing water retention time, suggesting uptake of N and P from the dissolved pool. Bacterial abundance, production and respiration increased in response to increased residence time and intracellular nutrient availability in agreement with the growth rate hypothesis. Our results reinforce the role of microorganisms in shaping the chemical environment in aquatic systems particularly at long water residence times and highlights the importance of this factor in influencing ecological stoichiometry in all aquatic ecosystems. PMID:28848518

  16. Redfield Ratios in Inland Waters: Higher Biological Control of C:N:P Ratios in Tropical Semi-arid High Water Residence Time Lakes.

    PubMed

    They, Ng H; Amado, André M; Cotner, James B

    2017-01-01

    The canonical Redfield C:N:P ratio for algal biomass is often not achieved in inland waters due to higher C and N content and more variability when compared to the oceans. This has been attributed to much lower residence times and higher contributions of the watershed to the total organic matter pool of continental ecosystems. In this study we examined the effect of water residence times in low latitude lakes (in a gradient from humid to a semi-arid region) on seston elemental ratios in different size fractions. We used lake water specific conductivity as a proxy for residence time in a region of Eastern Brazil where there is a strong precipitation gradient. The C:P ratios decreased in the seston and bacterial size-fractions and increased in the dissolved fraction with increasing water retention time, suggesting uptake of N and P from the dissolved pool. Bacterial abundance, production and respiration increased in response to increased residence time and intracellular nutrient availability in agreement with the growth rate hypothesis. Our results reinforce the role of microorganisms in shaping the chemical environment in aquatic systems particularly at long water residence times and highlights the importance of this factor in influencing ecological stoichiometry in all aquatic ecosystems.

  17. Inland Wetlands.

    ERIC Educational Resources Information Center

    Area Cooperative Educational Services, New Haven, CT. Environmental Education Center.

    This material includes student guide sheets, reference materials, and tape script for the audio-tutorial unit on Inland Wetlands. A set of 35mm slides and an audio tape are used with the material. The material is designed for use with Connecticut schools, but it can be adapted to other localities. The materials emphasize characteristics of inland…

  18. Cyanotoxins in Inland Lakes of the United States: Occurrence and Potential Recreational Health Risks in the EPA National Lakes Assessment 2007

    EPA Science Inventory

    A large nation-wide survey or cyanotoxlns (1161 lakes)in the United States (U.S.) was conducted dunng the EPA National Lakes Assessment 2007. Cyanotoxin data were compared with cyanobacteria abundance- and chlorophyll-based World Health Organization (WHO) thresholds and mouse to...

  19. Cyanotoxins in Inland Lakes of the United States: Occurrence and Potential Recreational Health Risks in the EPA National Lakes Assessment 2007

    EPA Science Inventory

    A large nation-wide survey or cyanotoxlns (1161 lakes)in the United States (U.S.) was conducted dunng the EPA National Lakes Assessment 2007. Cyanotoxin data were compared with cyanobacteria abundance- and chlorophyll-based World Health Organization (WHO) thresholds and mouse to...

  20. Cyanotoxins in inland lakes of the continental United States: Photic Zone Occurrence and potential recreational health risks in the 2007 Survey of the Nation's lakes

    EPA Science Inventory

    The largest spatial survey of cylindrospermosins, microcystins, and saxitoxins in the United States was conducted as part of the 2007 U.S. Survey of the Nation’s Lakes. Integrated photic zone samples were collected from 1,161 lakes during May-September 2007. Cyanotoxin, cya...

  1. Cruise report RV Inland Surveyer Cruise IS-98; the bathymetry of Lake Tahoe, California-Nevada, August 2 through August 17, 1998, Lake Tahoe, California and Nevada

    USGS Publications Warehouse

    Gardner, James V.; Mayer, Larry A.; Hughes-Clarke, John

    1998-01-01

    The major objective of cruise IS-98 was to map the bathymetry of Lake Tahoe, California-Nevada (Fig. 1) to fulfill a commitment made during the Lake Tahoe Presidential Forum in 1997. The only existing bathymetry of Lake Tahoe, collected in 1923, was recently compiled by Rowe and Stone (1997), but the data density is inadequate for the level of scientific studies ongoing and anticipated in the near future for Lake Tahoe. Recent advances in marine multibeam-sonar capabilities now permit a cost-effective way, to precisely map the bathymetry of large areas of the ocean floor with 100% coverage. Cruise IS-98 applied this state-of-the-art ocean technology to Lake Tahoe. The newest of these high-resolution multibeam mapping systems also simultaneously collects backscatter (similar to sidescan sonar) imagery that results in a complimentary and co-registered data set that is related to the distribution of lake-floor materials and textures. The two types of maps that resulted from this cruise provide the multidisiplinary Lake Tahoe research community an unprecedented set of base maps upon which to build their studies. This report describes the high-resolution multibeam mapping system used at Lake Tahoe, outlines the data-processing steps used to produce the maps, and includes the daily log of the cruise.

  2. Cyanotoxins in inland lakes of the continental United States: Photic Zone Occurrence and potential recreational health risks in the 2007 Survey of the Nation's lakes

    EPA Science Inventory

    The largest spatial survey of cylindrospermosins, microcystins, and saxitoxins in the United States was conducted as part of the 2007 U.S. Survey of the Nation’s Lakes. Integrated photic zone samples were collected from 1,161 lakes during May-September 2007. Cyanotoxin, cya...

  3. Stratigraphic and microfossil evidence for hydroclimate changes over the middle to late Holocene in the northern Bahamas from an inland saline lake

    NASA Astrophysics Data System (ADS)

    van Hengstum, P. J.; Maale, G. E.; Donnelly, J. P.; Onac, B. P.; Sullivan, R.; Winkler, T. S.; Albury, N. A.

    2016-12-01

    No Man's Land is one of the largest inland lakes on the Little Bahama Bank in the northern Bahamas, so its paleoenvironmental history may provide insight into how the regional hydroclimate developed over the Holocene. In its modern state, the site is shallow (<3 m), brackish (20.6 psu), 170 m in diameter, and located 700 m from the coastline. Prior to 6400 Cal yrs BP, the accumulation of peat deposits and no aquatic invertebrates (e.g., ostracodes, foraminifera, aquatic mollusks) indicate that the site was a terrestrial ecosystem. However, the site transitioned into a subaqueous freshwater environment at 6400 Cal yrs BP, and the site became a palustrine-lacustrine setting thereafter until 4200 Cal yrs BP. During this time, widespread palustrine-lacustrine carbonate deposition and the appearance of freshwater to low mesohaline microfossils indicates that the lake's salinity was likely oligohaline (charophytes, ostracodes: Candona annae, Cypridopsis vidua, foraminifera: Helenina davescottensis, mollusks: Planorbis, Hydrobia). A salinity increase at 4200 Cal yrs BP is inferred from the appearance of the ostracode Cyprideis americana that typically prefers salinities exceeding 10 psu, and deposition of laminated microbial mats. Thereafter, an organic- rich, algal sapropel unit accumulated that was devoid of any microfossils or mollusks. This unit suggests that the lake hosted a stratified water column, where surface waters supported phytoplankton primary productivity and corrosive or anoxic bottom water conditions either hampered microfossil growth or precluded their preservation. The transition to the modern environment ( 20 psu) at 2600 cal yrs BP is characterized by diversification of brackish ostracodes (Aurila floridana, Dolerocypria inopinata, and Hemicyprideis setipunctata), foraminifera (Elphidium spp., Ammonia beccarii, Triloculina oblonga) and mollusks (Anomalocardia, Cerithidea). Over the middle to late Holocene, it appears that the stratigraphic development

  4. Evaluating the performance of the newly-launched Landsat 8 sensor in detecting and mapping the spatial configuration of water hyacinth (Eichhornia crassipes) in inland lakes, Zimbabwe

    NASA Astrophysics Data System (ADS)

    Dube, Timothy; Mutanga, Onisimo; Sibanda, Mbulisi; Bangamwabo, Victor; Shoko, Cletah

    2017-08-01

    The remote sensing of freshwater resources is increasingly becoming important, due to increased patterns of water use and the current or projected impacts of climate change and the rapid invasion by lethal water weeds. This study therefore sought to explore the potential of the recently-launched Landsat 8 OLI/TIRS sensor in mapping invasive species in inland lakes. Specifically, the study compares the performance of the newly-launched Landsat 8 sensor, with more advanced sensor design and image acquisition approach to the traditional Landsat-7 ETM+ in detecting and mapping the water hyacinth (Eichhornia crassipes) invasive species across Lake Chivero, in Zimbabwe. The analysis of variance test was used to identify windows of spectral separability between water hyacinth and other land cover types. The results showed that portions of the visible (B3), NIR (B4), as well as the shortwave bands (Band 8, 9 and 10) of both Landsat 8 OLI and Landsat 7 ETM, exhibited windows of separability between water hyacinth and other land cover types. It was also observed that on the use of Landsat 8 OLI produced high overall classification accuracy of 72%, when compared Landsat 7 ETM, which yielded lower accuracy of 57%. Water hyacinth had optimal accuracies (i.e. 92%), when compared to other land cover types, based on Landsat 8 OLI data. However, when using Landsat 7 ETM data, classification accuracies of water hyacinth were relatively lower (i.e. 67%), when compared to other land cover types (i.e. water with accuracy of 100%). Spectral curves of the old, intermediate and the young water hyacinth in Lake Chivero based on: (a) Landsat 8 OLI, and (b) Landsat 7 ETM were derived. Overall, the findings of this study underscores the relevance of the new generation multispectral sensors in providing primary data-source required for mapping the spatial distribution, and even configuration of water weeds at lower or no cost over time and space.

  5. Hydrogeochemical evolution of inland lakes' water: A study of major element geochemistry in the Wadi El Raiyan depression, Egypt.

    PubMed

    Mohamed, Essam A; El-Kammar, Ahmed M; Yehia, Mohamed M; Abu Salem, Hend S

    2015-11-01

    Wadi El Raiyan is a great depression located southwest of Cairo in the Western Desert of Egypt. Lake Qarun, located north of the study area, is a closed basin with a high evaporation rate. The source of water in the lake is agricultural and municipal drainage from the El Faiyum province. In 1973, Wadi El Raiyan was connected with the agricultural wastewater drainage system of the Faiyum province and received water that exceeded the capacity of Lake Qarun. Two hydrogeological regimes have been established in the area: (i) higher cultivated land and (ii) lower Wadi El Raiyan depression lakes. The agricultural drainage water of the cultivated land has been collected in one main drain (El Wadi Drain) and directed toward the Wadi El Raiyan depression, forming two lakes at different elevations (upper and lower). In the summer of 2012, the major chemical components were studied using data from 36 stations distributed over both hydrogeological regimes in addition to one water sample collected from Bahr Youssef, the main source of freshwater for the Faiyum province. Chemical analyses were made collaboratively. The major ion geochemical evolution of the drainage water recharging the El Raiyan depression was examined. Geochemically, the Bahr Youssef sample is considered the starting point in the geochemical evolution of the studied surface water. In the cultivated area, major-ion chemistry is generally influenced by chemical weathering of rocks and minerals that are associated with anthropogenic inputs, as well as diffuse urban and/or agricultural drainage. In the depression lakes, the water chemistry generally exhibits an evaporation-dependent evolutionary trend that is further modified by cation exchange and precipitation of carbonate minerals.

  6. High genetic diversity and novelty in eukaryotic plankton assemblages inhabiting saline lakes in the Qaidam basin.

    PubMed

    Wang, Jiali; Wang, Fang; Chu, Limin; Wang, Hao; Zhong, Zhiping; Liu, Zhipei; Gao, Jianyong; Duan, Hairong

    2014-01-01

    Saline lakes are intriguing ecosystems harboring extremely productive microbial communities in spite of their extreme environmental conditions. We performed a comprehensive analysis of the genetic diversity (18S rRNA gene) of the planktonic microbial eukaryotes (nano- and picoeukaryotes) in six different inland saline lakes located in the Qaidam Basin. The novelty level are high, with about 11.23% of the whole dataset showing <90% identity to any previously reported sequence in GenBank. At least 4 operational taxonomic units (OTUs) in mesosaline lakes, while up to eighteen OTUs in hypersaline lakes show very low CCM and CEM scores, indicating that these sequences are highly distantly related to any existing sequence. Most of the 18S rRNA gene sequence reads obtained in investigated mesosaline lakes is closely related to Holozoa group (48.13%), whereas Stramenopiles (26.65%) and Alveolates (10.84%) are the next most common groups. Hypersaline lakes in the Qaidam Basin are also dominated by Holozoa group, accounting for 26.65% of the total number of sequence reads. Notably, Chlorophyta group are only found in high abundance in Lake Gasikule (28.00%), whereas less represented in other hypersaline lakes such as Gahai (0.50%) and Xiaochaidan (1.15%). Further analysis show that the compositions of planktonic eukaryotic assemblages are also most variable between different sampling sites in the same lake. Out of the parameters, four show significant correlation to this CCA: altitude, calcium, sodium and potassium concentrations. Overall, this study shows important gaps in the current knowledge about planktonic microbial eukaryotes inhabiting Qaidam Basin (hyper) saline water bodies. The identified diversity and novelty patterns among eukaryotic plankton assemblages in saline lake are of great importance for understanding and interpreting their ecology and evolution.

  7. High Genetic Diversity and Novelty in Eukaryotic Plankton Assemblages Inhabiting Saline Lakes in the Qaidam Basin

    PubMed Central

    Wang, Jiali; Wang, Fang; Chu, Limin; Wang, Hao; Zhong, Zhiping; Liu, Zhipei; Gao, Jianyong; Duan, Hairong

    2014-01-01

    Saline lakes are intriguing ecosystems harboring extremely productive microbial communities in spite of their extreme environmental conditions. We performed a comprehensive analysis of the genetic diversity (18S rRNA gene) of the planktonic microbial eukaryotes (nano- and picoeukaryotes) in six different inland saline lakes located in the Qaidam Basin. The novelty level are high, with about 11.23% of the whole dataset showing <90% identity to any previously reported sequence in GenBank. At least 4 operational taxonomic units (OTUs) in mesosaline lakes, while up to eighteen OTUs in hypersaline lakes show very low CCM and CEM scores, indicating that these sequences are highly distantly related to any existing sequence. Most of the 18S rRNA gene sequence reads obtained in investigated mesosaline lakes is closely related to Holozoa group (48.13%), whereas Stramenopiles (26.65%) and Alveolates (10.84%) are the next most common groups. Hypersaline lakes in the Qaidam Basin are also dominated by Holozoa group, accounting for 26.65% of the total number of sequence reads. Notably, Chlorophyta group are only found in high abundance in Lake Gasikule (28.00%), whereas less represented in other hypersaline lakes such as Gahai (0.50%) and Xiaochaidan (1.15%). Further analysis show that the compositions of planktonic eukaryotic assemblages are also most variable between different sampling sites in the same lake. Out of the parameters, four show significant correlation to this CCA: altitude, calcium, sodium and potassium concentrations. Overall, this study shows important gaps in the current knowledge about planktonic microbial eukaryotes inhabiting Qaidam Basin (hyper) saline water bodies. The identified diversity and novelty patterns among eukaryotic plankton assemblages in saline lake are of great importance for understanding and interpreting their ecology and evolution. PMID:25401703

  8. 77 FR 62435 - Inland Waterways Navigation Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-15

    ... SECURITY Coast Guard 33 CFR Part 162 RIN 1625-AB84 Inland Waterways Navigation Regulations AGENCY: Coast... Inland Waterways Navigation Regulations (77 FR 27007). We received 1 comment. Specifically, Lake Carriers... 33 CFR 162.138(a)(1)(ii) will lessen navigation restrictions on the public and on private...

  9. Environmental geochemistry of dissolved and biogenic silicon and its nutrient limitation effects in an inland lake, China.

    PubMed

    Lü, Changwei; He, Jiang; Wang, Bing; Zhou, Bin; Wang, Wei; Fan, Mingde

    2015-07-01

    Silicon (Si) processing and retention play a key role in nutrients biogeochemistry cycling in aquatic environment. In order to interpret the possibility of Si limitation, multivariate analysis was performed based on stoichiometric nutrients balance, distribution characteristics of dissolved silicon (DSi) and biogenic silica (BSi), adsorption behavior, and response relation of BSi with paleoenvironment in water-sediment system of Lake Daihai. The spatial distributions of DSi and BSi in the water-sediment system indicated that terrigenous inputs (such as the weathering of rock and soil in the drainage basin) was the main sources of Si. Meanwhile, grain sizes of sediments, water hydrogeochemistry, and space competition between diatoms and submergent or emerging plants also played important roles in regulating BSi spatial distributions. The sediments from the lake presented obvious releasing trend of Si at low initial concentrations (≤ 3 mg/L) in adsorption experiments, indicating that the sediments were the source of Si to the overlying water. Furthermore, the good response relation between BSi and paleoenvironment observed in the sediment profiles from Lake Daihai indicated that the main reasons for Si limitation to siliceous plankton were different during different periods. The multi-evidences of distribution characteristics, stoichiometric nutrient balance, adsorption behaviors, and response to paleoenvironment were jointly indicative of Si limitation on the primary production of siliceous plankton in Lake Daihai.

  10. Traces of microbial activity in the deep sediment of the Dead Sea: How is life influencing the sedimentary record of this hypersaline lake ?

    NASA Astrophysics Data System (ADS)

    Thomas, Camille; Ebert, Yael; Kiro, Yael; Stein, Mordechai; Ariztegui, Daniel

    2016-04-01

    As part of the ICDP-sponsored Dead Sea Deep Drilling Project (DSDDP), a multi-disciplinary study has been carried out to understand the influence that microbial communities can have on the Dead Sea sedimentary record. Organic matter (lipids) and DNA extraction have been performed along the main core retrieved from the center of the modern Dead Sea. They revealed different associations of microbial communities, influenced by changing climatic and limnological regimes during sedimentation. Moreover, imaging and chemical characterization of authigenic iron-sulfur minerals have revealed the unexpected presence of an active sulfur cycle in the sediment. In particular, their morphology and Fe/S ratios are coherent with incomplete sulfate reduction, limited by sulfur reduction, and often resulting in the preservation of greigite. In glacial period intervals, pyritization may be complete, indicating full sulfate reduction probably allowed by significant accumulation of organic matter in the alternating aragonite and detritus (aad) facies. The DSDDP core provides a unique opportunity to investigate deep diagenetic processes and to assess the role of microbial activity in the Dead Sea hypersaline sediment. Our study shows that this microbial activity influences the carbon and sulfur phases, as well as magnetic fractions, potentially affecting proxies used for paleoenvironmental and paleoclimatic reconstructions.

  11. Characterization of Halanaerobaculum tunisiense gen. nov., sp. nov., a new halophilic fermentative, strictly anaerobic bacterium isolated from a hypersaline lake in Tunisia.

    PubMed

    Hedi, Abdeljabbar; Fardeau, Marie-Laure; Sadfi, Najla; Boudabous, Abdellatif; Ollivier, Bernard; Cayol, Jean-Luc

    2009-03-01

    A new halophilic anaerobe was isolated from the hypersaline surface sediments of El-Djerid Chott, Tunisia. The isolate, designated as strain 6SANG, grew at NaCl concentrations ranging from 14 to 30%, with an optimum at 20-22%. Strain 6SANG was a non-spore-forming, non-motile, rod-shaped bacterium, appearing singly, in pairs, or occasionally as long chains (0.7-1 x 4-13 microm) and showed a Gram-negative-like cell wall pattern. It grew optimally at pH values between 7.2 and 7.4, but had a very broad pH range for growth (5.9-8.4). Optimum temperature for growth was 42 degrees C (range 30-50 degrees C). Strain 6SANG required yeast extract for growth on sugars. Glucose, sucrose, galactose, mannose, maltose, cellobiose, pyruvate, and starch were fermented. The end products from glucose fermentation were acetate, butyrate, lactate, H(2), and CO(2). The G + C ratio of the DNA was 34.3 mol%. Strain 6SANG exhibited 16S rRNA gene sequence similarity values of 91-92% with members of the genus Halobacteroides, H. halobius being its closest phylogenetic relative. Based on phenotypic and phylogenetic characteristics, we propose that this bacterium be classified as a novel species of a novel genus, Halanaerobaculum tunisiense gen. nov., sp. nov. The type strain is 6SANG(T) (=DSM 19997(T)=JCM 15060(T)).

  12. Remotely sensed surface temperature variation of an inland saline lake over the central Qinghai-Tibet Plateau

    NASA Astrophysics Data System (ADS)

    Ke, Linghong; Song, Chunqiao

    2014-12-01

    Research on surface water temperature (SWT) variations in large lakes over the Qinghai-Tibet Plateau (QTP) has been limited by lack of in situ measurements. By taking advantage of the increased availability of remotely sensed observations, this study investigated SWT variation of Siling Co in central QTP by processing complete MODIS Land surface temperature (LST) images over the lake covering from 2001 to 2013. The temporal (diurnal, intra-annul and inter-annul) variations of Siling Co SWT as well as the spatial patterns were analyzed. The results show that on average from late December to mid-April the lake is in a mixing state of water and ice and drastic diurnal temperature differences occur, especially along the shallow shoreline areas. The extent of spatial variations in monthly SWT ranges from 1.25 °C to 3.5 °C, and particularly large at nighttime and in winter months. The spatial patterns of annual average SWT were likely impacted by the cooling effect of river inflow from the west and east side of the lake. The annual cycle of spatial pattern of SWT is characterized by seasonal reversions between the shallow littoral regions and deep parts due to different heat capacity. Compared to the deep regions, the littoral shallow shoreline areas warms up quickly in spring and summer, and cool down drastically in autumn and winter, showing large diurnal and seasonal variation amplitudes of SWT. Two cold belt zones in the western and eastern side of the lake and warm patches along the southwestern and northeastern shorelines are shaped by the combined effects of the lakebed topography and river runoff. Overall, the lake-averaged SWT increased at a rate of 0.26 °C/decade during 2001-2013. Faster increase of temperature was found at nighttime (0.34 °C/decade) and in winter and spring, consistent with the asymmetric warming pattern over land areas reported in prior studies. The rate of temperature increase over Siling Co is remarkably lower than that over Bangoin

  13. Recent Inland Water Temperature Trends

    NASA Astrophysics Data System (ADS)

    Hook, Simon; Healey, Nathan; Lenters, John; O'Reilly, Catherine

    2016-04-01

    We are using thermal infrared satellite data in conjunction with in situ measurements to produce water temperatures for all the large inland water bodies in North America and the rest of the world for potential use as climate indicator. Recent studies have revealed significant warming of inland waters throughout the world. The observed rate of warming is - in many cases - greater than that of the ambient air temperature. These rapid, unprecedented changes in inland water temperatures have profound implications for lake hydrodynamics, productivity, and biotic communities. Scientists are just beginning to understand the global extent, regional patterns, physical mechanisms, and ecological consequences of lake warming. As part of our work we have collected thermal infrared satellite data from those satellite sensors that provide long-term and frequent spaceborne thermal infrared measurements of inland waters including ATSR, AVHRR, and MODIS and used these to examine trends in water surface temperature for approximately 169 of the largest inland water bodies in the world. We are now extending this work to generate temperature time-series of all North American inland water bodies that are sufficiently large to be studied using 1km resolution satellite data for the last 3 decades, approximately 268 lakes. These data are then being related to changes in the surface air temperature and compared with regional trends in water surface temperature derived from CMIP5/IPCC model simulations/projections to better predict future temperature changes. We will discuss the available datasets and processing methodologies together with the patterns they reveal based on recent changes in the global warming, with a particular focus on the inland waters of the southwestern USA.

  14. Evidence that sea lampreys (Petromyzon marinus) complete their life cycle within a tributary of the Laurentian Great Lakes by parasitizing fishes in inland lakes

    USGS Publications Warehouse

    Johnson, Nicholas; Twohey, Michael B.; Miehls, Scott M.; Cwalinski, Tim A; Godby, Neal A; Lochet, Aude; Slade, Jeffrey W.; Jubar, Aaron K.; Siefkes, Michael J.

    2016-01-01

    The sea lamprey (Petromyzon marinus) invaded the upper Laurentian Great Lakes and feeds on valued fish. The Cheboygan River, Michigan, USA, is a large sea lamprey producing tributary to Lake Huron and despite having a renovated dam 2 km from the river mouth that presumably blocks sea lamprey spawning migrations, the watershed upstream of the dam remains infested with larval sea lamprey. A navigational lock near the dam has been hypothesized as the means of escapement of adult sea lampreys from Lake Huron and source of the upper river population (H1). However, an alternative hypothesis (H2) is that some sea lampreys complete their life cycle upstream of the dam, without entering Lake Huron. To evaluate the alternative hypothesis, we gathered angler reports of lamprey wounds on game fishes upstream of the dam, and captured adult sea lampreys downstream and upstream of the dam to contrast abundance, run timing, size, and statolith microchemistry. Results indicate that a small population of adult sea lampreys (n < 200) completed their life cycle upstream of the dam during 2013 and 2014. This is the most comprehensive evidence that sea lampreys complete their life history within a tributary of the upper Great Lakes, and indicates that similar landlocked populations could occur in other watersheds. Because the adult sea lamprey population upstream of the dam is small, complete elimination of the already low adult escapement from Lake Huron might allow multiple control tactics such as lampricides, trapping, and sterile male release to eradicate the population.

  15. Northeast sector of the Greenland Ice Sheet to undergo the greatest inland expansion of supraglacial lakes during the 21st century

    NASA Astrophysics Data System (ADS)

    Ignéczi, Ádám.; Sole, Andrew J.; Livingstone, Stephen J.; Leeson, Amber A.; Fettweis, Xavier; Selmes, Nick; Gourmelen, Noel; Briggs, Kate

    2016-09-01

    The formation and rapid drainage of supraglacial lakes (SGL) influences the mass balance and dynamics of the Greenland Ice Sheet (GrIS). Although SGLs are expected to spread inland during the 21st century due to atmospheric warming, less is known about their future spatial distribution and volume. We use GrIS surface elevation model and regional climate model outputs to show that at the end of the 21st century (2070-2099) approximately 9.8 ± 3.9 km3 (+113% compared to 1980-2009) and 12.6 ± 5 km3 (+174%) of meltwater could be stored in SGLs under moderate and high representative concentration pathways (RCP 4.5 and 8.5), respectively. The largest increase is expected in the northeastern sector of the GrIS (191% in RCP 4.5 and 320% in RCP 8.5), whereas in west Greenland, where the most SGLs are currently observed, the future increase will be relatively moderate (55% in RCP 4.5 and 68% in RCP 8.5).

  16. Analysis of community composition of sulfur-oxidizing bacteria in hypersaline and soda lakes using soxB as a functional molecular marker.

    PubMed

    Tourova, Tatjana P; Slobodova, Natalija V; Bumazhkin, Boris K; Kolganova, Tatjana V; Muyzer, Gerard; Sorokin, Dimitry Y

    2013-05-01

    The diversity of soxB gene encoding a key enzyme of the Sox pathway sulfate thiohydrolase has been investigated in pure cultures of various halophilic and haloalkaliphilic sulfur-oxidizing bacteria (SOB) and in salt and soda lakes in southwestern Siberia and Egypt. The gene was detected in the majority of strains belonging to eleven SOB genera excluding members of genera Thiohalospira and Thioalkalimicrobium. The uncultured diversity of soxB in salt and soda lakes was low with a majority of detected sequences belonging to autotrophic SOB from the Gammaproteobacteria. In addition, the soxB analysis allowed detection of putative heterotrophic Gamma- and Alphaproteobacterial SOB yet unknown in culture. All clone libraries obtained from soda lakes contained soxB belonging to the genus Thioalkalivibrio in agreement with the cultivation results. Besides, representatives of the genera Halothiobacillus, Marinobacter, and Halochromatium and of the family Rhodobacteraceae have been detected in both type of saline lakes. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  17. [Landscape ecological risk assessment and its spatio-temporal variations in Ebinur Lake region of inland arid area].

    PubMed

    Zhang, Yue; Zhang, Fei; Zhou, Mei; Li, Xiao-hang; Ren, Yan; Wang, Juan

    2016-01-01

    The typical region of the Ebinur Lake Basin was chosen as study area. Landsat TM/OLI images for 1998, 2011 and 2013 were obtained. In the study area, landscape was classified into six types, including cropland, woodland, grassland, water body, bare lake bed, salinized land and unutilized land. Landscape indices and ecological risk index were calculated and spatially interpolated for the whole region, which was divided into five different risk zones: extremely low, low, moderate, high and extremely high ecological risk. They were carried out for assessing the spatio-temporal changes in ecological risk for each landscape pattern. The results showed that the regional landscape patterns had experienced significant changes, and the increase in the area of croplands was the main trend in landscape evolution from 1998-2013. The main part of the regional ecosystem faced extremely high risk in 1998, high risk in 2011 and low risk in 2013. The ecological risk level of the study area was significantly decreased in the overall period, and the total area of change from high to low risk was much greater than those from low to high risk.

  18. [Three wavelengths factor model of chlorophyll concentrations inversion based on different spectral dominating factors for inland lake].

    PubMed

    Shi, Kun; Li, Yun-Mei; Liu, Zhong-Hua; Xu, Yi-Fan; Xu, Xini; Wu, Chuan-Qing; Zhu, Li

    2010-12-01

    A hierarchical cluster analysis is applied to the data set of R(rs) spectra. Combing the inherent optical and measured water color characteristics, we determine factors of the variability for each class of R(rs) spectra. The R(rs) measured from Lake Taihu, Chaohu, Dianchi and Three Gorges Reservoir can be divided into three spectrally distinct classes: class 1, class 2 and class 3. Class 1 is associated with water optical property dominated by total suspended matter and phytoplankton. Class 2 is associated with water optical property dominated by phytoplankton. And Class 3 is associated with water optical property dominated by total suspended matter. The three wavelengths factor Chlorophyll a concentration inversion models were developed according to different class water optical characteristics, which means relative error and RMSE are 23.8% and 8.5 mg/m3, and have higher accuracy than the model developed without classification.

  19. Comparison of different semi-empirical algorithms to estimate chlorophyll-a concentration in inland lake water.

    PubMed

    Duan, Hongtao; Ma, Ronghua; Xu, Jingping; Zhang, Yuanzhi; Zhang, Bai

    2010-11-01

    Based on in situ water sampling and field spectral measurement from June to September 2004 in Lake Chagan, a comparison of several existing semi-empirical algorithms to determine chlorophyll-a (Chl-a) content was made by applying them to the field spectra and in situ chlorophyll measurements. Results indicated that the first derivative of reflectance was well correlated with Chl-a. The highest correlation between the first derivative and Chl-a was at 680 nm. The two-band model, NIR/red ratio of R710/670, was also an effective predictor of Chl-a concentration. Since the two-band ratios model is a special case of the three-band model developed recently, three-band model in Lake Chagan showed a higher resolution. The new algorithm named reverse continuum removal relies on the reflectance peak at 700 nm whose shape and position depend strongly upon chlorophyll concentration: The depth and area of the peak above a baseline showed a linear relationship to Chl-a concentration. All of the algorithms mentioned proved to be of value and can be used to predict Chl-a concentration. Best results were obtained by using the algorithms of the first derivative, which yielded R2 around 0.74 and RMSE around 6.39 μg/l. The two-band and three-band algorithms were further applied to MERIS when filed spectral were resampled with regard to their center wavelengths. Both algorithms showed an adequate precision, and the differences on the outcome were small with R2=0.70 and 0.71.

  20. Using radon-222 and radium-226 isotopes to deduce the functioning of a coastal aquifer adjacent to a hypersaline lake in NW Iran

    NASA Astrophysics Data System (ADS)

    Amiri, Vahab; Nakhaei, Mohammad; Lak, Razyeh

    2017-10-01

    This study aims to assess the hydrogeochemistry of coastal groundwater, the occurrence of 222Rn and 226Ra, and their isotopic response to salinity and associated chemical compositions of groundwater in the coastal Urmia Aquifer (UA) at the western side of Urmia Lake (UL). The results of the PCA show that 87.3% of groundwater chemistry changes are controlled by six principal components. The interaction between groundwater and coastal igneous and metamorphic rocks in eastern areas (next to the UL) results in complex hydrogeochemical conditions than western areas. Based on correlation of U and salinity, some coastal samples display conservative and the others non-conservative behaviors. Differed from most previous studies, 226Ra and 222Rn concentrations in coastal groundwater samples of UA do not show a good correlation with salinity. Given 10% of groundwater 222Rn is originated from host rocks, the radon concentrations recorded in the coastal groundwater samples are relatively in range that can effectively be supplied by the local rocks (5-49 Bq/l). Results of different chemical and isotopic parameters in this area indicate that there is no direct connection between fresh groundwater and UL saltwater. This is because that the hard and thick salty layer in the lakebed acts as an impermeable barrier to prevent the underground hydraulic connection. Results show that removing the salty layer of UL as an option to progress in rehabilitation program of this lake may result in more hydraulic connection between the lake and groundwater resources in some areas.

  1. Land use change and its effects on water quality in typical inland lake of arid area in China.

    PubMed

    Cui, Hong; Zhou, Xiaode; Guo, Mengjing; Wei, Wu

    2016-07-01

    Land-use change is very important for determining and assessing the influence of human activity on aquatic environment of rivers and lakes. The present work with Bosten River basin as the subject, analyzes features of dynamic land-use change of the basin from 1993 to 2013, in order to study the influence of land-use pattern change on the basin water quality, according to the land-use/land-cover(LUCC) chart from 2000 to 2013 made by ArcGIS and ENVI. It shows cultivated land, wetland and forestland constitute most of Bosten River basin, taking up over 41.7% of the total; from 1993-2000, LUCC of the basin is relatively small, with an increase of cultivated land, residential-industry land, water wetlands by 15.09%-18.33%,most of which are transformed from forestland, grassland and unused land; from 2000-2013, LUCC of the basin is relatively significant, with a continuing and bigger increase of cultivated land and Residential-industry area, most of which are transformed from water wetlands and unused land. Based on analysis of landuse pattern and water quality index, it can be told that water pollution is positively correlated to cultivated land and residential-industry area and negatively correlated to water and grassland. Also, the influence of land-use pattern change on water quality has been discussed, whose finding can serve as the scientific evidence for land-use optimization and water pollution control.

  2. 46 CFR 11.433 - Service requirements for master of Great Lakes and inland steam or motor vessels of any gross tons.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... motor vessels of more than 1600 gross tons; or, (b) Two years of service as master of inland (excluding... inland steam or motor vessels of any gross tons. 11.433 Section 11.433 Shipping COAST GUARD, DEPARTMENT... steam or motor vessels of any gross tons. The minimum service required to qualify an applicant for an...

  3. Isolation and characterization of an indigenous isolate of Dunaliella sp. for beta-carotene and glycerol production from a hypersaline lake in India.

    PubMed

    Phadwal, Kanchan; Singh, P K

    2003-01-01

    Dunaliella, a green alga grows in a wide range of marine and freshwater habitats such as oceans, brine lakes, salt marshes and salt-water ditches near the sea, predominantly in water bodies containing more than 10% salt. Sambhar salt lake, Rajasthan (India) was found as one of the natural habitat of Dunaliella sp. The species was isolated and screened for accumulation of beta-carotene and glycerol. It was studied for the growth attributes like total protein, optical density, total chlorophyll, total carotenoid, beta-carotene and glycerol. Under unstressed physico-chemical conditions the maximum beta-carotene and glycerol observed was 1.15 pg/cell and 94.26 pg/cell respectively. The stress (salt stress (NaCl), high light intensities and continuous light) allowed the alga to accumulate high beta-carotene (approximately 4.21 pg/cell under 118.18 micromole m(-2) s(-1) of light intensity) without massive reduction in biomass content. This opens up new avenues for exploring this strain for future research and its commercial exploitation.

  4. Thioalkalimicrobium cyclicum sp. nov. and Thioalkalivibrio jannaschii sp. nov., novel species of haloalkaliphilic, obligately chemolithoautotrophic sulfur-oxidizing bacteria from hypersaline alkaline Mono Lake (California).

    PubMed

    Sorokin, Dimitry Yu; Gorlenko, Vladimir M; Tourova, Tat'yana P; Tsapin, Alexandre I; Nealson, Kenneth H; Kuenen, Gijs J

    2002-05-01

    Two strains of haloalkaliphilic, obligately autotrophic, sulfur-oxidizing bacteria were isolated from the oxygen-sulfide interface water layer of stratified alkaline and saline Mono Lake, California, USA. Strain ALM 1T was a dominant species in enrichment on moderate-saline, carbonate-buffered medium (0.6 M total Na+, pH 10) with thiosulfate as an energy source and nitrate as a nitrogen source. Cells of ALM 1T are open ring-shaped and are non-motile. It has a high growth rate and activity of thiosulfate and sulfide oxidation and very low sulfur-oxidizing activity. Genetic comparison and phylogenetic analysis suggested that ALM 1T (= DSM 14477T = JCM 11371T) represents a new species of the genus Thioalkalimicrobium in the gamma-Proteobacteria, for which the name Thioalkalimicrobium cyclicum sp. nov. is proposed. Another Mono Lake isolate, strain ALM 2T, dominated in enrichment on a medium containing 2 M total Na+ (pH 10). It is a motile vibrio which tolerates up to 4 M Na+ and produces a membrane-bound yellow pigment. Phylogenetic analysis placed ALM 2T as a member of genus Thioalkalivibrio in the gamma-Proteobacteria, although its DNA hybridization with the representative strains of this genus was only about 30%. On the basis of genetic and phenotypic properties, strain ALM 2T (= DSM 14478T = JCM 11372T) is proposed as Thioalkalivibrio jannaschii sp. nov..

  5. Fishing Farmers or Farming Fishers? Fishing Typology of Inland Small-Scale Fishing Households and Fisheries Management in Singkarak Lake, West Sumatra, Indonesia

    NASA Astrophysics Data System (ADS)

    Yuerlita; Perret, Sylvain Roger; Shivakoti, Ganesh P.

    2013-07-01

    Technical and socio-economic characteristics are known to determine different types of fishers and their livelihood strategies. Faced with declining fish and water resources, small-scale fisheries engage into transformations in livelihood and fishing practices. The paper is an attempt to understand these changes and their socio-economic patterns, in the case of Singkarak Lake in West Sumatra, Indonesia. Based upon the hypothesis that riparian communities have diverse, complex yet structured and dynamic livelihood systems, the paper's main objective is to study, document and model the actual diversity in livelihood, practices and performance of inland small-scale fisheries along the Singkarak Lake, to picture how households are adapted to the situation, and propose an updated, workable model (typology) of those for policy. Principal component analysis and cluster analysis were used to develop a typology of fishing households. The results show that small-scale fishers can be classified into different types characterized by distinct livelihood strategies. Three household types are identified, namely "farming fishers" households (type I, 30 %), "fishing farmers" households (type II, 30 %), and "mainly fishers" households (type III, 40 %). There are significant differences among these groups in the number of boats owned, annual fishing income, agriculture income and farming experience. Type I consists of farming fishers, well equipped, with high fishing costs and income, yet with the lowest return on fishing assets. They are also landowners with farming income, showing the lowest return on land capital. Type II includes poor fishing farmers, landowners with higher farming income; they show the highest return on land asset. They have less fishing equipment, costs and income. Type III (mainly fishers) consists of poorer, younger fishers, with highest return on fishing assets and on fishing costs. They have little land, low farming income, and diversified livelihood

  6. Fishing farmers or farming fishers? Fishing typology of inland small-scale fishing households and fisheries management in singkarak lake, west sumatra, indonesia.

    PubMed

    Yuerlita; Perret, Sylvain Roger; Shivakoti, Ganesh P

    2013-07-01

    Technical and socio-economic characteristics are known to determine different types of fishers and their livelihood strategies. Faced with declining fish and water resources, small-scale fisheries engage into transformations in livelihood and fishing practices. The paper is an attempt to understand these changes and their socio-economic patterns, in the case of Singkarak Lake in West Sumatra, Indonesia. Based upon the hypothesis that riparian communities have diverse, complex yet structured and dynamic livelihood systems, the paper's main objective is to study, document and model the actual diversity in livelihood, practices and performance of inland small-scale fisheries along the Singkarak Lake, to picture how households are adapted to the situation, and propose an updated, workable model (typology) of those for policy. Principal component analysis and cluster analysis were used to develop a typology of fishing households. The results show that small-scale fishers can be classified into different types characterized by distinct livelihood strategies. Three household types are identified, namely "farming fishers" households (type I, 30 %), "fishing farmers" households (type II, 30 %), and "mainly fishers" households (type III, 40 %). There are significant differences among these groups in the number of boats owned, annual fishing income, agriculture income and farming experience. Type I consists of farming fishers, well equipped, with high fishing costs and income, yet with the lowest return on fishing assets. They are also landowners with farming income, showing the lowest return on land capital. Type II includes poor fishing farmers, landowners with higher farming income; they show the highest return on land asset. They have less fishing equipment, costs and income. Type III (mainly fishers) consists of poorer, younger fishers, with highest return on fishing assets and on fishing costs. They have little land, low farming income, and diversified livelihood

  7. Cyanotoxins in inland lakes of the United States: Occurrence and potential recreational health risks in the EPA National Lakes Assessment 2007

    USGS Publications Warehouse

    Loftin, Keith A.; Graham, Jennifer; Elizabeth Hilborn,; Sarah Lehmann,; Meyer, Michael T.; Dietze, Julie E.; Griffith, Christopher

    2016-01-01

    A large nation-wide survey of cyanotoxins (1161 lakes) in the United States (U.S.) was conducted during the EPA National Lakes Assessment 2007. Cyanotoxin data were compared with cyanobacteria abundance- and chlorophyll-based World Health Organization (WHO) thresholds and mouse toxicity data to evaluate potential recreational risks. Cylindrospermopsins, microcystins, and saxitoxins were detected (ELISA) in 4.0, 32, and 7.7% of samples with mean concentrations of 0.56, 3.0, and 0.061 mg/L, respectively (detections only). Co-occurrence of the three cyanotoxin classes was rare (0.32%) when at least one toxin was detected. Cyanobacteria were present and dominant in 98 and 76% of samples, respectively. Potential anatoxin-, cylindrospermopsin-, microcystin-, and saxitoxin-producing cyanobacteria occurred in 81, 67, 95, and 79% of samples, respectively. Anatoxin-a and nodularin-R were detected (LC/MS/MS) in 15 and 3.7% samples (n = 27). The WHO moderate and high risk thresholds for microcystins, cyanobacteria abundance, and total chlorophyll were exceeded in 1.1, 27, and 44% of samples, respectively. Complete agreement by all three WHO microcystin metrics occurred in 27% of samples. This suggests that WHO microcystin metrics based on total chlorophyll and cyanobacterial abundance can overestimate microcystin risk when compared to WHO microcystin thresholds. The lack of parity among the WHO thresholds was expected since chlorophyll is common amongst all phytoplankton and not all cyanobacteria produce microcystins.

  8. Bacteriophage in polar inland waters

    USGS Publications Warehouse

    Säwström, Christin; Lisle, John; Anesio, A.M.; Priscu, John C.; Laybourn-Parry, J.

    2008-01-01

    Bacteriophages are found wherever microbial life is present and play a significant role in aquatic ecosystems. They mediate microbial abundance, production, respiration, diversity, genetic transfer, nutrient cycling and particle size distribution. Most studies of bacteriophage ecology have been undertaken at temperate latitudes. Data on bacteriophages in polar inland waters are scant but the indications are that they play an active and dynamic role in these microbially dominated polar ecosystems. This review summarises what is presently known about polar inland bacteriophages, ranging from subglacial Antarctic lakes to glacial ecosystems in the Arctic. The review examines interactions between bacteriophages and their hosts and the abiotic and biotic variables that influence these interactions in polar inland waters. In addition, we consider the proportion of the bacteria in Arctic and Antarctic lake and glacial waters that are lysogenic and visibly infected with viruses. We assess the relevance of bacteriophages in the microbial loop in the extreme environments of Antarctic and Arctic inland waters with an emphasis on carbon cycling.

  9. [Diversity of diazotrophs in the sediments of hypersaline salt and soda lakes analyzed with the use of the nifH gene as a molecular marker].

    PubMed

    Turova, T P; Slobodova, N V; Bumazhkin, B K; Sukhacheva, M V; Sorokin, D Iu

    2014-01-01

    Phylogenetic analysis of the nifH genes, encoding the Fe protein of the nitrogenas enzymatic complex, was carried out for pure cultures of anoxygenic phototrophic bacteria of diverse origin, as well as for heterotrophic alkaliphilic sulfate reducers isolated from saline and soda lakes. Topology of the nitrogenase tree correlated with that of the 16S rRNAgene tree to a considerable degree; which niade it possible to use the nifH gene as a molecular marker for investigation of diazotrophic bacterialcommunities in silty sediments of saline and sodalakes. Although diazotrophs were revealed in all environmentalsamples, their phylogenetic diversity was relatively low. Sulfate-reducing deltaproteobacteria and photo- and chemotrophicgammaproteobacteria were predominant in samples integrated over sediment thickness. Analysis of samples fromthe upper sediment layers revealed predominance of phototrophic diazotrophs of various phyla, including purple sulfur and nonsulfur proteobacteria, green nonsulfur bacteria, heliobacteria; and cyanobacteria. Some phylotypes could not be identified, probably indicating the presence of bacterial groups which have not yet been studied by conventional microbiological techniques.

  10. Analysis of ammonia-oxidizing bacteria from hypersaline Mono Lake, California, on the basis of 16S rRNA sequences.

    PubMed

    Ward, B B; Martino, D P; Diaz, M C; Joye, S B

    2000-07-01

    Ammonia-oxidizing bacteria were detected by PCR amplification of DNA extracted from filtered water samples throughout the water column of Mono Lake, California. Ammonia-oxidizing members of the beta subdivision of the division Proteobacteria (beta-subdivision Proteobacteria) were detected using previously characterized PCR primers; target sequences were detected by direct amplification in both surface water and below the chemocline. Denaturing gradient gel electrophoresis analysis indicated the presence of at least four different beta-subdivision ammonia oxidizers in some samples. Subsequent sequencing of amplified 16S rDNA fragments verified the presence of sequences very similar to those of cultured Nitrosomonas strains. Two separate analyses, carried out under different conditions (different reagents, locations, PCR machines, sequencers, etc.), 2 years apart, detected similar ranges of sequence diversity in these samples. It seems likely that the physiological diversity of nitrifiers exceeds the diversity of their ribosomal sequences and that these sequences represent members of the Nitrosomonas europaea group that are acclimated to alkaline, high-salinity environments. Primers specific for Nitrosococcus oceanus, a marine ammonia-oxidizing bacterium in the gamma subdivision of the Proteobacteria, did not amplify target from any samples.

  11. Assessing the chemical behavior and spatial distribution of yttrium and rare earth elements (YREEs) in a coastal aquifer adjacent to the Urmia Hypersaline Lake, NW Iran.

    PubMed

    Sohrabi, Nassim; Kalantari, Nasrollah; Amiri, Vahab; Nakhaei, Mohammad

    2017-07-15

    This study aims to shed light on the seasonal behavior of yttrium and rare earth elements (YREEs) in the Urmia Aquifer (UA), in the immediate vicinity of Urmia Lake (UL) in Iran. Samples of groundwater, collected under dry and wet conditions in coastal wells of UA, suggest a large degree of variability in both YREE abundance and normalized patterns. Although weathering or water-rock interactions (between the surface/groundwater and rock samples) were predicted to be the most probable source in explaining YREEs in groundwater samples, results to the contrary indicate that the groundwater do not inherit aquifer rock-like YREE signatures in the study area; this might be due to the relative stability of YREEs during the process of water-rock interactions, which suggest that methods based on YREEs can be beneficial in discrimination of water sources. Furthermore, findings demonstrated no significant relationship between Ce/Ce* and salinity (0.08 and 0.05 in wet and dry seasons, respectively), and between Eu/Eu* and salinity (0.1 and -0.04 in wet and dry seasons, respectively). Dissimilarity of patterns of YREEs in rock and water samples reveals YREEs as no conservative tracers in determining the UL saltwater intrusion into coastal groundwater. Therefore, the groundwater YREE concentrations and fractionation patterns in UA warrant controlling by coastal aquifer need to be controlled by other chemical weathering, adsorption, desorption, and solution complexation reactions. Finally, comparison of REE concentration values in groundwater samples with corresponding indicative admissible drinking water concentrations (IAC) demonstrated their suitability for drinking purposes.

  12. Resilience of estuarine phytoplankton and their temporal variability along salinity gradients during drought and hypersalinity

    NASA Astrophysics Data System (ADS)

    Nche-Fambo, F. A.; Scharler, U. M.; Tirok, K.

    2015-06-01

    In South African estuaries, there is no knowledge on the resilience and variability in phytoplankton communities under conditions of hypersalinity, extended droughts and reverse salinity gradients. Phytoplankton composition, abundance and biomass vary with changes in environmental variables and taxa richness declines specifically under hypersaline conditions. This research thus investigated the phytoplankton community composition, its resilience and variability under highly variable and extreme environmental conditions in an estuarine lake system (Lake St. Lucia, South Africa) over one year. The lake system was characterised by a reverse salinity gradient with hypersalinity furthest from the estuarine inlet during the study period. During this study, 78 taxa were recorded: 56 diatoms, eight green algae, one cryptophyte, seven cyanobacteria and six dinoflagellates. Taxon variability and resilience depended on their ability to tolerate high salinities. Consequently, the phytoplankton communities as well as total abundance and biomass differed along the salinity gradient and over time with salinity as the main determinant. Cyanobacteria were dominant in hypersaline conditions, dinoflagellates in marine-brackish salinities, green algae and cryptophytes in lower salinities (brackish) and diatoms were abundant in marine-brackish salinities but survived in hypersaline conditions. Total abundance and biomass ranged from 3.66 × 103 to 1.11 × 109 Cells/L and 1.21 × 106 to 1.46 × 1010 pgC/L respectively, with the highest values observed under hypersaline conditions. Therefore, even under highly variable, extreme environmental conditions and hypersalinity the phytoplankton community as a whole was resilient enough to maintain a relatively high biomass throughout the study period. The resilience of few dominant taxa, such as Cyanothece, Spirulina, Protoperidinium and Nitzschia and the dominance of other common genera such as Chlamydomonas, Chroomonas, Navicula, Gyrosigma

  13. Glacier and lake variations in the inland closed basins at high altitude on the Tibetan Plateau using remote sensing and GIS technologies

    NASA Astrophysics Data System (ADS)

    Ye, Q.; Yao, T.; Naruse, R.; Zhen, H.

    2008-12-01

    As a contribution to studies of the impact of climate change on glaciers and lakes in high-altitude closed basins of the western Himalayas, we present spatial and temporal variations of glaciers and lakes in the Mapam Yumco Basin on the Tibetan Plateau, by means of Geographical Information System and Remote Sensing techniques. Our results show that both glacier and lake areas in Mapam Yumco Basin decreased from 1974 to 2003. Glaciers in the basin have receded due to the warmer climate, in total by ~ 7.53 km2 (0.26 km2 a-1 or 0.25 % a-1) during 1974-2003 (c.f. ~ 0.07 % a-1 in nearby Yamzhog Yumco Basin, and 0.18% a-1, the mean glacier recession rate over China since the 1960s). During the same period, lake area decreased by 34.16 km2 (1.18 km2 a-1 or 4.37 % of whole lake area in the basin) in total, where decreased by 1.43 km2 a-1 on average (with lake shrinkage amounting to 1.70 km2 a-1 in some areas and lake growth to 0.27 km2 a-1 in others) during 1974-1990, by 1.55 km2 a-1 (with lake shrinkage amounting to 2.15 km2 a-1 in some areas and lake growth to 0.60 km2 a-1 in others) during 1990--1999, while enlarged by 0.66 km2 a-1 (with lake shrinkage amounting to 2.24 km2 a-1 and lake growth to 2.89 km2 a-1) during 1999--2003 over the past three decades. It is suggested that both enlargement and reduction of lakes were accelerated, which might be an indicator for an accelerated water cycle process over the Tibetan Plateau in a warming climate.

  14. Ground-based measurements and dual-Doppler analysis of 3-D wind fields and atmospheric circulations induced by a meso-γ-scale inland lake

    NASA Astrophysics Data System (ADS)

    Asefi-Najafabady, Salvi; Knupp, Kevin; Mecikalski, John R.; Welch, Ronald M.; Phillips, Dustin

    2010-12-01

    This paper presents a high-resolution dual-Doppler analysis of lake breeze mesoscale circulation induced by an elongated reservoir with a mean width of ˜2 km and an area of 125 km2. Compared to previous meso-γ-scale lake breeze studies based on point measurements or aircraft observations, the present study provides both a unique quantification and a high-resolution spatial and temporal 3-D visualization (several hundred meters and 5 min, respectively) of the kinematic structure of the lake breeze initiation and evolution. Visible satellite images show a cloud-free zone over the lake and adjacent land areas that was promoted by subsidence associated with the lake breeze circulation. The background synoptic-scale wind flow was almost parallel to the major axis of the lake, and distinct lake breeze frontal zones formed along both shorelines spanning the length of the lake. Dual-Doppler analyses showed updrafts in the frontal zones, perturbation horizontal velocities of 1.5 m s-1 on both sides of the lake, and maximum downdrafts of 2 m s-1 centered over the lake. Vertical vorticity in the boundary layer was produced by differential friction between the smooth lake and adjacent land. The circulations are robust and are maintained during the day against a minor change in background wind direction. The study shows that the circulations produced by a small lake can generate significant mesoscale circulations that influence local climatology and identifies the importance of including such small mesoscale processes in global forecast models.

  15. Hypersaline cyanobacterial mats as indicators of elevated tropical hurricane activity and associated climate change.

    PubMed

    Paerl, Hans W; Steppe, Timothy F; Buchan, Kenneth C; Potts, Malcolm

    2003-03-01

    The Atlantic hurricanes of 1999 caused widespread environmental damage throughout the Caribbean and US mid-Atlantic coastal regions. However, these storms also proved beneficial to certain microbial habitats; specifically, cyanobacteria-dominated mats. Modern mats represent the oldest known biological communities on earth, stromatolites. Contemporary mats are dominant biological communities in the hypersaline Bahamian lakes along the Atlantic hurricane track. We examined the impacts of varying levels of hypersalinity on 2 processes controlling mat growth, photosynthesis and nitrogen fixation, in Salt Pond, San Salvador Island, Bahamas. Hypersalinity (> 5 times seawater salinity) proved highly inhibitory to these processes. Freshwater input from Hurricane Floyd and other large storms alleviated this salt-inhibition. A predicted 10 to 40 year increase in Atlantic hurricane activity accompanied by more frequent "freshening" events will enhance mat productivity, CO2 sequestration and nutrient cycling. Cyanobacterial mats are sensitive short- and long-term indicators of climatic and ecological changes impacting these and other waterstressed environments.

  16. Datasets related to in-land water for limnology and remote sensing applications: distance-to-land, distance-to-water, water-body identifier and lake-centre co-ordinates.

    PubMed

    Carrea, Laura; Embury, Owen; Merchant, Christopher J

    2015-11-01

    Datasets containing information to locate and identify water bodies have been generated from data locating static-water-bodies with resolution of about 300 m (1/360(∘)) recently released by the Land Cover Climate Change Initiative (LC CCI) of the European Space Agency. The LC CCI water-bodies dataset has been obtained from multi-temporal metrics based on time series of the backscattered intensity recorded by ASAR on Envisat between 2005 and 2010. The new derived datasets provide coherently: distance to land, distance to water, water-body identifiers and lake-centre locations. The water-body identifier dataset locates the water bodies assigning the identifiers of the Global Lakes and Wetlands Database (GLWD), and lake centres are defined for in-land waters for which GLWD IDs were determined. The new datasets therefore link recent lake/reservoir/wetlands extent to the GLWD, together with a set of coordinates which locates unambiguously the water bodies in the database. Information on distance-to-land for each water cell and the distance-to-water for each land cell has many potential applications in remote sensing, where the applicability of geophysical retrieval algorithms may be affected by the presence of water or land within a satellite field of view (image pixel). During the generation and validation of the datasets some limitations of the GLWD database and of the LC CCI water-bodies mask have been found. Some examples of the inaccuracies/limitations are presented and discussed. Temporal change in water-body extent is common. Future versions of the LC CCI dataset are planned to represent temporal variation, and this will permit these derived datasets to be updated.

  17. Anaerobic bacteria from hypersaline environments.

    PubMed Central

    Ollivier, B; Caumette, P; Garcia, J L; Mah, R A

    1994-01-01

    Strictly anaerobic halophiles, namely fermentative, sulfate-reducing, homoacetogenic, phototrophic, and methanogenic bacteria are involved in the oxidation of organic carbon in hypersaline environments. To date, six anaerobic fermentative genera, containing nine species, have been described. Two of them are homoacetogens. Six species belong to the family Haloanaerobiaceae, as indicated by their unique 16S rRNA oligonucleotide sequences. Desulfohalobium retbaense and Desulfovibrio halophilus represent the only two moderately halophilic sulfate reducers so far reported. Among anoxygenic phototrophic anaerobes, a few purple bacteria with optimal growth at salinities between 6 and 11% NaCl have been isolated from hypersaline habitats. They belong to the genera Rhodospirillum, Chromatium, Thiocapsa, and Ectothiorhodospira. The commonest organisms isolated so far are Chromatium salexigens, Thiocapsa halophila, and Rhodospirillum salinarum. Extremely halophilic purple bacteria have most commonly been isolated from alkaline brines and require about 20 to 25% NaCl for optimal growth. They belong to the family Ectothiorodhospiraceae. Their osmoregulation involves synthesis or uptake of compatible solutes such as glycine-betaine that accumulate in their cytoplasm. The existence of methanogens in hypersaline environments is related to the presence of noncompetitive substrates such as methylamines, which originate mainly from the breakdown of osmoregulatory amines. Methanogenesis probably does not contribute to the mineralization of carbohydrates at NaCl concentrations higher than 15%. Above this concentration, sulfate reduction is probably the main way to oxidize H2 (although at rates too low to use up all the H2 formed) and occupies a terminal function kn the degradation of carbohydrates. Three genera and five species of halophilic methylotrophic methanogens have been reported. A bloom of phototrophic bacteria in the marine salterns of Salins-de-Giraud, located on the

  18. Anaerobic bacteria from hypersaline environments.

    PubMed

    Ollivier, B; Caumette, P; Garcia, J L; Mah, R A

    1994-03-01

    Strictly anaerobic halophiles, namely fermentative, sulfate-reducing, homoacetogenic, phototrophic, and methanogenic bacteria are involved in the oxidation of organic carbon in hypersaline environments. To date, six anaerobic fermentative genera, containing nine species, have been described. Two of them are homoacetogens. Six species belong to the family Haloanaerobiaceae, as indicated by their unique 16S rRNA oligonucleotide sequences. Desulfohalobium retbaense and Desulfovibrio halophilus represent the only two moderately halophilic sulfate reducers so far reported. Among anoxygenic phototrophic anaerobes, a few purple bacteria with optimal growth at salinities between 6 and 11% NaCl have been isolated from hypersaline habitats. They belong to the genera Rhodospirillum, Chromatium, Thiocapsa, and Ectothiorhodospira. The commonest organisms isolated so far are Chromatium salexigens, Thiocapsa halophila, and Rhodospirillum salinarum. Extremely halophilic purple bacteria have most commonly been isolated from alkaline brines and require about 20 to 25% NaCl for optimal growth. They belong to the family Ectothiorodhospiraceae. Their osmoregulation involves synthesis or uptake of compatible solutes such as glycine-betaine that accumulate in their cytoplasm. The existence of methanogens in hypersaline environments is related to the presence of noncompetitive substrates such as methylamines, which originate mainly from the breakdown of osmoregulatory amines. Methanogenesis probably does not contribute to the mineralization of carbohydrates at NaCl concentrations higher than 15%. Above this concentration, sulfate reduction is probably the main way to oxidize H2 (although at rates too low to use up all the H2 formed) and occupies a terminal function kn the degradation of carbohydrates. Three genera and five species of halophilic methylotrophic methanogens have been reported. A bloom of phototrophic bacteria in the marine salterns of Salins-de-Giraud, located on the

  19. Microbial diversity and complexity in hypersaline environments: a preliminary assessment.

    PubMed

    Litchfield, C D; Gillevet, P M

    2002-01-01

    The microbial communities in solar salterns and a soda lake have been characterized using two techniques: BIOLOG, to estimate the metabolic potential, and amplicon length heterogeneity analysis, to estimate the molecular diversity of these communities. Both techniques demonstrated that the halophilic Bacteria and halophilic Archaea populations in the Eilat, Israel saltern are dynamic communities with extensive metabolic potentials and changing community structures. Halophilic Bacteria were detected in Mono Lake and the lower salinity ponds at the Shark Bay saltern in Western Australia, except when the crystallizer samples were stressed by exposure to Acid Green Dye #9899. At Shark Bay, halophilic Archaea were found only in the crystallizer samples. These data confirm both the metabolic diversity and the phylogenetic complexity of the microbial communities and assert the need to develop more versatile media for the cultivation of the diversity of bacteria in hypersaline environments.

  20. Extractable organic halogens (EOX) in sediments from selected Polish rivers and lakes--a measure of the quality of the inland water environment.

    PubMed

    Niemirycz, Elzbieta; Kaczmarczyk, Anna; Błazejowski, Jerzy

    2005-09-01

    EOX in sediments from the two main Polish rivers (the Vistula and the Oder/Odra) as well as five lakes was assayed coulometrically and its values examined with respect to the location of the sample collection points. EOX values were found to increase near industrial areas and large urban agglomerations, although mean values--comparable for rivers and lakes--were similar to those recorded elsewhere. EOX tends to rise as TOC does so. On the other hand, the EOX:TOC ratio decreases sharply in the case of lakes, since TOC values there are roughly one order of magnitude higher than in rivers. Furthermore, the contents of selected polychlorinated biphenyls and organochlorine pesticides are directly related to EOX values. These relationships constitute a basis for the application of EOX as a parameter reflecting the level of organochlorine compounds in environmental quality evaluation.

  1. Biodegradation of petroleum hydrocarbons in hypersaline environments

    PubMed Central

    Martins, Luiz Fernando; Peixoto, Raquel Silva

    2012-01-01

    Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review. PMID:24031900

  2. Biodegradation of petroleum hydrocarbons in hypersaline environments.

    PubMed

    Martins, Luiz Fernando; Peixoto, Raquel Silva

    2012-07-01

    Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review.

  3. A multi-sensor approach to monitor the desiccation of Lake Urmia in Iran

    NASA Astrophysics Data System (ADS)

    Javad Tourian, Mohammad; Elmi, Omid; Sneeuw, Nico

    2013-04-01

    Lake Urmia, a hypersaline lake in northwestern Iran is under the threat of drying up. The high importance of the lake's watershed for agricultural purposes demands a comprehensive monitoring of the watershed's behaviour. Spaceborne sensors provide a number of novel ways to monitor the hydrological cycle and its interannual changes. The use of GRACE gravity data allows to determine continental water storage changes and to close the water budget on short time scales. Satellite altimetry can be used as a tool for monitoring inland water surface elevations. Optical satellite imagery and Synthetic Aperture Radar (SAR) provide the opportunity to monitor the spatial change in coastline, which can serv as a way to determine the water extent repeatedly in an appropriate time interval. In this study, water storage change from GRACE, surface water level over different parts of the lake from satellite altimetry together with surface water extent estimation from SAR and optical imagery are used and assimilated to monitor the lake's hydrological cycle. In addition to the spaceborne data, in situ observation of precipitation, groundwater level and temperature together with model based actual evapotranspiration are also employed for assimilation. A linear dynamic system consisting of a stochastic process model and observation equations is developed to assimilate the data from different sources. The dynamic system is solved by a Kalman filter to achieve an unbiased estimation with minimum variance. The results of the assimilation allow us to monitor the hydrological cycle with quantified error budgets over the lake.

  4. [Remote Sensing Estimation of Chlorophyll-a Concentration in Inland Lakes Based on GOCI Image and Optical Classification of Water Body].

    PubMed

    Feng, Chi; Jin, Qi; Wang, Yan-nan; Zhao, Li-na; Lu, Heng; Li, Yun-mei

    2015-05-01

    Chlorophyll-a as one of the important water quality parameters is often used as a measure of the level of water eutrophication. The 326 measured data collected from Lake Taihu and Lake Dongting were classified based on their measured values of remote sensing reflectance spectra using an automatic clustering algorithm-two-step method, and three water types were finally classified. According to the location and width of GOCI satellite bands, the specific algorithm to estimate chlorophyll-a concentration for different water body types was developed. The bands at 490 nm and 555 nm were used for water body type I , while bands at 660 nm and 443 nm were selected for water body type II and bands at 745 nm and 680 nm were applied for water body type III. The accuracy assessment showed that the mean relative error decreased from 49. 78% to 38. 91% , 24. 19% and 22. 90% for water body type I , II and III, respectively, while the root mean square error decreased from 14.10 µg · L(-1) to 4.87 µg · L(-1), 8.13 µg · L(-1) and 11.66 µg · L(-1) for water body type I, II and III, respectively. The overall mean relative error decreased from 49. 78% to 29. 59% after classification, while the overall root mean square error was reduced from 14.10 µg · L(-1) to 9.29 µg · L(-1) after classification. The retrieval accuracy was significantly improved after classification. The chlorophyll-a concentration in Lake Taihu was retrieved using the GOCI image on May 13, 2013. The results showed that there was a significantly diurnal variation in the concentration of chllorophyll-a on May 13, 2013, and the regions with higher chlorophyll-a concentration were mainly distributed in the Zhushan Bay, Meiliang Bay and Gonghu Bay, while the regions with lower values were mainly located in the centre of the lake and the southern region. The chlorophyll-a concentration reduced significantly after 10:00 in the southwestern region of Lake Taihu. This method of retrieving, after classification

  5. Thiohalorhabdus denitrificans gen. nov., sp. nov., an extremely halophilic, sulfur-oxidizing, deep-lineage gammaproteobacterium from hypersaline habitats.

    PubMed

    Sorokin, Dimitry Yu; Tourova, Tatjana P; Galinski, Erwin A; Muyzer, Gerard; Kuenen, J Gijs

    2008-12-01

    Seven strains of extremely halophilic and obligately chemolithoautotrophic sulfur-oxidizing bacteria (SOB) were enriched and isolated at 4 M NaCl from sediments of hypersaline inland lakes in south-eastern Siberia and a Mediterranean sea solar saltern. Cells of the novel isolates were spindle-like, long and non-motile rods with a Gram-negative type of cell wall. They were obligately chemolithoautotrophic SOB using thiosulfate and tetrathionate as electron donors and represent the first example of extremely halophilic chemolithoautotrophs that are able to grow anaerobically with nitrate as electron acceptor. The characteristic feature of the group was the production of large amounts of tetrathionate as an intermediate during the oxidation of thiosulfate to sulfate. With thiosulfate, the novel strains grew within the pH range from 6.5 to 8.2 (optimum at pH 7.5-7.8) and at NaCl concentrations from 1.5 to 4.0 M (optimum at 3.0 M). Cells grown at 4 M NaCl accumulated extremely high concentrations of glycine betaine as a compatible solute. The dominant cellular fatty acids were 10MeC(16 : 0) and C(16 : 0). Based on the DNA-DNA relatedness values, the isolates consisted of a single genomic species and had a similar phenotype. Phylogenetic analysis placed the novel bacteria in the class Gammaproteobacteria as an independent lineage with no significant relationship to any other genera in this class. On the basis of phenotypic and genotypic analysis, the group is proposed to represent a new genus, Thiohalorhabdus gen. nov., with Thiohalorhabdus denitrificans gen. nov., sp. nov. as the type species (type strain HL 19(T)=DSM 15699(T)=UNIQEM U223(T)).

  6. Do copepods inhabit hypersaline waters worldwide? A short review and discussion

    NASA Astrophysics Data System (ADS)

    Anufriieva, Elena V.

    2015-11-01

    A small number of copepod species have adapted to an existence in the extreme habitat of hypersaline water. 13 copepod species have been recorded in the hypersaline waters of Crimea (the largest peninsula in the Black Sea with over 50 hypersaline lakes). Summarizing our own and literature data, the author concludes that the Crimean extreme environment is not an exception: copepod species dwell in hypersaline waters worldwide. There are at least 26 copepod species around the world living at salinity above 100; among them 12 species are found at salinity higher than 200. In the Crimea Cletocamptus retrogressus is found at salinity 360×10-3 (with a density of 1 320 individuals/m3) and Arctodiaptomus salinus at salinity 300×10-3 (with a density of 343 individuals/m3). Those species are probably the most halotolerant copepod species in the world. High halotolerance of osmoconforming copepods may be explained by exoosmolyte consumption, mainly with food. High tolerance to many factors in adults, availability of resting stages, and an opportunity of long-distance transportation of resting stages by birds and/or winds are responsible for the wide geographic distribution of these halophilic copepods.

  7. Hypersaline Microbial Mat Lipid Biomarkers

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda L.; Embaye, Tsegereda; Turk, Kendra A.; Summons, Roger E.

    2002-01-01

    Lipid biomarkers and compound specific isotopic abundances are powerful tools for studies of contemporary microbial ecosystems. Knowledge of the relationship of biomarkers to microbial physiology and community structure creates important links for understanding the nature of early organisms and paleoenvironments. Our recent work has focused on the hypersaline microbial mats in evaporation ponds at Guerrero Negro, Baja California Sur, Mexico. Specific biomarkers for diatoms, cyanobacteria, archaea, green nonsulfur (GNS), sulfate reducing, sulfur oxidizing and methanotrophic bacteria have been identified. Analyses of the ester-bound fatty acids indicate a highly diverse microbial community, dominated by photosynthetic organisms at the surface. The delta C-13 of cyanobacterial biomarkers such as the monomethylalkanes and hopanoids are consistent with the delta C-13 measured for bulk mat (-10%o), while a GNS biomarker, wax esters (WXE), suggests a more depleted delta C-13 for GNS biomass (-16%o). This isotopic relationship is different than that observed in mats at Octopus Spring, Yellowstone National Park (YSNP) where GNS appear to grow photoheterotrophic ally. WXE abundance, while relatively low, is most pronounced in an anaerobic zone just below the cyanobacterial layer. The WXE isotope composition at GN suggests that these bacteria utilize photoautotrophy incorporating dissolved inorganic carbon (DIC) via the 3-hydroxypropionate pathway using H2S or H2.

  8. Hypersaline Microbial Mat Lipid Biomarkers

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda L.; Embaye, Tsegereda; Turk, Kendra A.; Summons, Roger E.

    2002-01-01

    Lipid biomarkers and compound specific isotopic abundances are powerful tools for studies of contemporary microbial ecosystems. Knowledge of the relationship of biomarkers to microbial physiology and community structure creates important links for understanding the nature of early organisms and paleoenvironments. Our recent work has focused on the hypersaline microbial mats in evaporation ponds at Guerrero Negro, Baja California Sur, Mexico. Specific biomarkers for diatoms, cyanobacteria, archaea, green nonsulfur (GNS), sulfate reducing, sulfur oxidizing and methanotrophic bacteria have been identified. Analyses of the ester-bound fatty acids indicate a highly diverse microbial community, dominated by photosynthetic organisms at the surface. The delta C-13 of cyanobacterial biomarkers such as the monomethylalkanes and hopanoids are consistent with the delta C-13 measured for bulk mat (-10%o), while a GNS biomarker, wax esters (WXE), suggests a more depleted delta C-13 for GNS biomass (-16%o). This isotopic relationship is different than that observed in mats at Octopus Spring, Yellowstone National Park (YSNP) where GNS appear to grow photoheterotrophic ally. WXE abundance, while relatively low, is most pronounced in an anaerobic zone just below the cyanobacterial layer. The WXE isotope composition at GN suggests that these bacteria utilize photoautotrophy incorporating dissolved inorganic carbon (DIC) via the 3-hydroxypropionate pathway using H2S or H2.

  9. Possible Origin of the High Incidence of Clostridium botulinum Type E in an Inland Bay (Green Bay of Lake Michigan)1

    PubMed Central

    Bott, Thomas L.; Johnson, Jodie; Foster, E. M.; Sugiyama, H.

    1968-01-01

    Bottom and shoreline sediments of Green Bay, northern Lake Michigan, and rivers of the Green Bay drainage basin, as well as soils of the surrounding land mass, were examined for Clostridium botulinum type E. Detection was based on identification of type E toxin in enrichment cultures and was influenced by many factors. Testing smaller amounts of sample in multiple cultures was more productive than examining large inocula in fewer cultures. Incubation at 30 C was unsatisfactory, but 14 days at 20 C or 7 days at 25 C gave good results. Mild heating (60 C for 30 min) of specimens reduced the incidence of positive findings. Freezing enrichment cultures prior to testing for toxicity eliminated many nonbotulinal toxic substances that killed mice. A control culture inoculated with type E spores was employed to show whether a specimen contained factors which could mask the presence of type E. Samples from 708 stations were tested in 2,446 cultures. Type E was found in nearly all underwater specimens of Green Bay and northern Lake Michigan but was present less frequently in samples taken along their shores. The incidence was still lower in the rivers emptying into Green Bay with the organism being rare on the shores of these rivers and in the soils of the land mass proper. Samples from the upper reaches of the rivers practically never contained type E. Runoff could deposit type E spores in Green Bay, but this is not considered to be the major factor in the high incidence of the organism. Multiplication in the bay itself is indicated. PMID:4870273

  10. Inland and coastal waters

    NASA Astrophysics Data System (ADS)

    Mouw, Colleen; Greb, Steven

    2012-09-01

    Workshop for Remote Sensing of Coastal and Inland Waters;Madison, Wisconsin, 20-22 June 2012 Coastal and inland water bodies, which have great value for recreation, food supply, commerce, transportation, and human health, have been experiencing external pressure from direct human activities and climate change. Given their societal and economic value, understanding issues of water quality, water quantity, and the impact of environmental change on the ecological and biogeochemical functioning of these water bodies is of interest to a broad range of communities. Remote sensing offers one of the most spatially and temporally comprehensive tools for observing these waters. While there has been some success with remotely observing these water bodies, many challenges still remain, including algorithm performance, atmospheric correction, the relationships between optical properties and biogeochemical parameters, sufficient spatial and spectral resolution, and a lack of uncertainty estimates over the wide range of environmental conditions encountered across these coastal and inland water bodies.

  11. 46 CFR 11.435 - Requirements for master of inland self-propelled vessels of unlimited tonnage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... year of service as first-class pilot (of other than canal and small lakes routes) or mate of Great... as mate inland or first-class pilot of Great Lakes and inland self-propelled vessels of unlimited... master or a qualified officer while holding a mate/first-class pilot license or MMC endorsement. (b) ...

  12. Global carbon dioxide emissions from inland waters

    USGS Publications Warehouse

    Raymond, Peter A.; Hartmann, Jens; Lauerwald, Ronny; Sobek, Sebastian; McDonald, Cory P.; Hoover, Mark; Butman, David; Striegl, Robert G.; Mayorga, Emilio; Humborg, Christoph; Kortelainen, Pirkko; Durr, Hans H.; Meybeck, Michel; Ciais, Philippe; Guth, Peter

    2013-01-01

    Carbon dioxide (CO2) transfer from inland waters to the atmosphere, known as CO2 evasion, is a component of the global carbon cycle. Global estimates of CO2 evasion have been hampered, however, by the lack of a framework for estimating the inland water surface area and gas transfer velocity and by the absence of a global CO2 database. Here we report regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity. We obtain global CO2 evasion rates of 1.8   petagrams of carbon (Pg C) per year from streams and rivers and 0.32  Pg C yr−1 from lakes and reservoirs, where the upper and lower limits are respectively the 5th and 95th confidence interval percentiles. The resulting global evasion rate of 2.1 Pg C yr−1 is higher than previous estimates owing to a larger stream and river evasion rate. Our analysis predicts global hotspots in stream and river evasion, with about 70 per cent of the flux occurring over just 20 per cent of the land surface. The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally.

  13. Global carbon dioxide emissions from inland waters.

    PubMed

    Raymond, Peter A; Hartmann, Jens; Lauerwald, Ronny; Sobek, Sebastian; McDonald, Cory; Hoover, Mark; Butman, David; Striegl, Robert; Mayorga, Emilio; Humborg, Christoph; Kortelainen, Pirkko; Dürr, Hans; Meybeck, Michel; Ciais, Philippe; Guth, Peter

    2013-11-21

    Carbon dioxide (CO2) transfer from inland waters to the atmosphere, known as CO2 evasion, is a component of the global carbon cycle. Global estimates of CO2 evasion have been hampered, however, by the lack of a framework for estimating the inland water surface area and gas transfer velocity and by the absence of a global CO2 database. Here we report regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity. We obtain global CO2 evasion rates of 1.8(+0.25)(-0.25)  petagrams of carbon (Pg C) per year from streams and rivers and 0.32(+0.52)(-0.26)  Pg C yr(-1) from lakes and reservoirs, where the upper and lower limits are respectively the 5th and 95th confidence interval percentiles. The resulting global evasion rate of 2.1 Pg C yr(-1) is higher than previous estimates owing to a larger stream and river evasion rate. Our analysis predicts global hotspots in stream and river evasion, with about 70 per cent of the flux occurring over just 20 per cent of the land surface. The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally.

  14. Phylogenetic status of brown trout Salmo trutta populations in five rivers from the southern Caspian Sea and two inland lake basins, Iran: a morphogenetic approach.

    PubMed

    Hashemzadeh Segherloo, I; Farahmand, H; Abdoli, A; Bernatchez, L; Primmer, C R; Swatdipong, A; Karami, M; Khalili, B

    2012-10-01

    Interrelationships, origin and phylogenetic affinities of brown trout Salmo trutta populations from the southern Caspian Sea basin, Orumieh and Namak Lake basins in Iran were analysed from complete mtDNA control region sequences, 12 microsatellite loci and morphological characters. Among 129 specimens from six populations, seven haplotypes were observed. Based on mtDNA haplotype data, the Orumieh and southern Caspian populations did not differ significantly, but the Namak basin-Karaj population presented a unique haplotype closely related to the haplotypes of the other populations (0·1% Kimura two-parameter, K2P divergence). All Iranian haplotypes clustered as a distinct group within the Danube phylogenetic grouping, with an average K2P distance of 0·41% relative to other Danubian haplotypes. The Karaj haplotype in the Namak basin was related to a haplotype (Da26) formerly identified in the Tigris basin in Turkey, to a Salmo trutta oxianus haplotype from the Aral Sea basin, and to haplotype Da1a with two mutational steps, as well as to other Iranian haplotypes with one to two mutational steps, which may indicate a centre of origin in the Caspian basin. In contrast to results of the mtDNA analysis, more pronounced differentiation was observed among the populations studied in the morphological and microsatellite DNA data, except for the two populations from the Orumieh basin, which were similar, possibly due to anthropogenic causes. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  15. Monitoring Change in Great Salt Lake

    NASA Astrophysics Data System (ADS)

    Naftz, David; Angeroth, Cory; Freeman, Michael; Rowland, Ryan; Carling, Gregory

    2013-08-01

    Great Salt Lake is the largest hypersaline lake in the Western Hemisphere and the fourth largest terminal lake in the world (Figure 1). The open water and adjacent wetlands of the Great Salt Lake ecosystem support millions of migratory waterfowl and shorebirds from throughout the Western Hemisphere [Aldrich and Paul, 2002]. In addition, the area is of important economic value: Brine shrimp (Artemia franciscana) residing in Great Salt Lake support an aquaculture shrimp cyst industry with annual revenues as high as $60 million.

  16. Inland wetland mineral soils

    Treesearch

    Kimberly P. Wickland; Alex V. Krusche; Randall K. Kolka; Ayaka W. Kishimoto-Mo; Rodney A. Chimner; Stephen Ogle; Nalin. Srivastava

    2013-01-01

    This chapter provides supplementary guidance for estimating and reporting greenhouse gas (GHG) emissions and removals from managed lands with Inland Wetland Mineral Soils (IWMS) for all land-use categories (see Chapter 1 and decision tree in Chapter 1 in this supplement for what is specifically covered in this chapter in relationship to other chapters in this...

  17. Inland water resources

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The work is reported of the panel concerning the application of space technology to the improved management of the nation's inland resources. The progress since the 1967-68 study is briefly reviewed. The data needed for the management of inlet water ways, and the potential benefits of better management are discussed along with 16 proposed demonstration projects.

  18. Landsat Thematic Mapper monitoring of turbid inland water quality

    NASA Technical Reports Server (NTRS)

    Lathrop, Richard G., Jr.

    1992-01-01

    This study reports on an investigation of water quality calibration algorithms under turbid inland water conditions using Landsat Thematic Mapper (TM) multispectral digital data. TM data and water quality observations (total suspended solids and Secchi disk depth) were obtained near-simultaneously and related using linear regression techniques. The relationships between reflectance and water quality for Green Bay and Lake Michigan were compared with results for Yellowstone and Jackson Lakes, Wyoming. Results show similarities in the water quality-reflectance relationships, however, the algorithms derived for Green Bay - Lake Michigan cannot be extrapolated to Yellowstone and Jackson Lake conditions.

  19. Landsat Thematic Mapper monitoring of turbid inland water quality

    SciTech Connect

    Lathrop, R.G., JR. )

    1992-04-01

    This study reports on an investigation of water quality calibration algorithms under turbid inland water conditions using Landsat Thematic Mapper (TM) multispectral digital data. TM data and water quality observations (total suspended solids and Secchi disk depth) were obtained near-simultaneously and related using linear regression techniques. The relationships between reflectance and water quality for Green Bay and Lake Michigan were compared with results for Yellowstone and Jackson Lakes, Wyoming. Results show similarities in the water quality-reflectance relationships, however, the algorithms derived for Green Bay - Lake Michigan cannot be extrapolated to Yellowstone and Jackson Lake conditions. 17 refs.

  20. Water Quality, Cyanobacteria, and Environmental Factors and Their Relations to Microcystin Concentrations for Use in Predictive Models at Ohio Lake Erie and Inland Lake Recreational Sites, 2013-14

    USGS Publications Warehouse

    Francy, Donna S.; Graham, Jennifer L.; Stelzer, Erin A.; Ecker, Christopher D.; Brady, Amie M G.; Pam Struffolino,; Loftin, Keith A.

    2015-11-06

    The results of this study showed that water-quality and environmental variables are promising for use in site-specific daily or long-term predictive models. In order to develop more accurate models to predict toxin concentrations at freshwater lake sites, data need to be collected more frequently and for consecutive days in future studies.

  1. Biocoenosis response to hydrological variability in Southern Africa during the last 84 ka BP: A study of lipid biomarkers and compound-specific stable carbon and hydrogen isotopes from the hypersaline Lake Tswaing

    NASA Astrophysics Data System (ADS)

    Schmidt, F.; Oberhänsli, H.; Wilkes, H.

    2014-01-01

    Sea surface temperature (SST) changes in the SW Indian and SE South Atlantic Ocean are proposed to have controlled environmental changes at the southern tip of the African continent during the past. For a better understanding of the hydrological variations and their environmental impact during the past 84 ka before present (BP), we analyzed lipid biomarkers and their stable carbon (δ13C) and hydrogen (δD) isotopic compositions in sediments from Lake Tswaing (25°24‧30″ S, 28°04‧59″ E). δD values of long-chain n-alkanes from higher plants varied between - 155 and - 82‰ and matched well with SST gradient changes between the tropical and subtropical SW Indian Ocean. Increased SSTs correlate with deuterium-depleted δD values of n-alkanes and indicate a higher convection transporting more moisture across South Africa in the time from 84 to 80 ka BP, during the marine isotope stage (MIS) 4 and from 50 to 39 ka BP. During these humid periods high amounts of organic matter (up to 9.8% total organic carbon (TOC)) were deposited in Lake Tswaing. Periods with deuterium-enriched δD values of n-alkanes (76 ka BP, 73 to 69 ka BP, 55 to 51 ka BP, and 31.4 to 12.6 ka BP), indicating dry climate and increased lake water salinity, were associated with lower TOC contents and a higher degradation state of the terrestrial organic matter. We occasionally detected algae-derived C37- and C38-alkenones in the core, particularly in times when lake salinity and alkalinity were elevated. The disappearance of alkenones around 25 ka BP was accompanied by highly depleted δD values of n-alkanes from aquatic organisms (- 180‰ for n-C23) indicating a substantial freshening of the lake water. The vegetation surrounding Lake Tswaing during the last 84 ka BP consisted mainly of savanna-type plants, such as trees and shrubs with varying contributions from C4 grasses. The latter predominated particularly at the end of MIS 5 and during arid climatic conditions in MIS 3. We show that

  2. Virus-bacterium interactions in water and sediment of West African inland aquatic systems.

    PubMed

    Bettarel, Yvan; Bouvy, Marc; Dumont, Claire; Sime-Ngando, Télesphore

    2006-08-01

    The ecology of virioplankton in tropical aquatic ecosystems is poorly documented, and in particular, there are no references concerning African continental waters in the literature. In this study, we examined virus-bacterium interactions in the pelagic and benthic zones of seven contrasting shallow inland waters in Senegal, including one hypersaline lake. SYBR Gold-stained samples revealed that in the surface layers of the sites, the numbers of viruses were in the same range as the numbers of viruses reported previously for productive temperate systems. Despite high bacterial production rates, the percentages of visibly infected cells (as determined by transmission electron microscopy) were similar to the lowest percentages (range, 0.3 to 1.1%; mean, 0.5%) found previously at pelagic freshwater or marine sites, presumably because of the local environmental and climatic conditions. Since the percentages of lysogenic bacteria were consistently less than 8% for pelagic and benthic samples, lysogeny did not appear to be a dominant strategy for virus propagation at these sites. In the benthic samples, viruses were highly concentrated, but paradoxically, no bacteria were visibly infected. This suggests that sediment provides good conditions for virus preservation but ironically is an unfavorable environment for proliferation. In addition, given the comparable size distributions of viruses in the water and sediment samples, our results support the paradigm that aquatic viruses are ubiquitous and may have moved between the two compartments of the shallow systems examined. Overall, this study provides additional information about the relevance of viruses in tropical areas and indicates that the intensity of virus-bacterium interactions in benthic habitats may lower than the intensity in the adjacent bodies of water.

  3. Virus-Bacterium Interactions in Water and Sediment of West African Inland Aquatic Systems

    PubMed Central

    Bettarel, Yvan; Bouvy, Marc; Dumont, Claire; Sime-Ngando, Télesphore

    2006-01-01

    The ecology of virioplankton in tropical aquatic ecosystems is poorly documented, and in particular, there are no references concerning African continental waters in the literature. In this study, we examined virus-bacterium interactions in the pelagic and benthic zones of seven contrasting shallow inland waters in Senegal, including one hypersaline lake. SYBR Gold-stained samples revealed that in the surface layers of the sites, the numbers of viruses were in the same range as the numbers of viruses reported previously for productive temperate systems. Despite high bacterial production rates, the percentages of visibly infected cells (as determined by transmission electron microscopy) were similar to the lowest percentages (range, 0.3 to 1.1%; mean, 0.5%) found previously at pelagic freshwater or marine sites, presumably because of the local environmental and climatic conditions. Since the percentages of lysogenic bacteria were consistently less than 8% for pelagic and benthic samples, lysogeny did not appear to be a dominant strategy for virus propagation at these sites. In the benthic samples, viruses were highly concentrated, but paradoxically, no bacteria were visibly infected. This suggests that sediment provides good conditions for virus preservation but ironically is an unfavorable environment for proliferation. In addition, given the comparable size distributions of viruses in the water and sediment samples, our results support the paradigm that aquatic viruses are ubiquitous and may have moved between the two compartments of the shallow systems examined. Overall, this study provides additional information about the relevance of viruses in tropical areas and indicates that the intensity of virus-bacterium interactions in benthic habitats may lower than the intensity in the adjacent bodies of water. PMID:16885276

  4. Inland Water Temperature and the recent Global Warming Hiatus

    NASA Astrophysics Data System (ADS)

    Hook, S. J.; Healey, N.; Lenters, J. D.; O'Reilly, C.

    2015-12-01

    We are using thermal infrared satellite data in conjunction with in situ measurements to produce water temperatures for all the large inland water bodies in North America and the rest of the world for potential use as climate indicator. Recent studies have revealed significant warming of inland waters throughout the world. The observed rate of warming is - in many cases - greater than that of the ambient air temperature. These rapid, unprecedented changes in inland water temperatures have profound implications for lake hydrodynamics, productivity, and biotic communities. Scientists are just beginning to understand the global extent, regional patterns, physical mechanisms, and ecological consequences of lake warming. As part of our earlier studies we have collected thermal infrared satellite data from those satellite sensors that provide long-term and frequent spaceborne thermal infrared measurements of inland waters including ATSR, AVHRR, and MODIS and used these to examine trends in water surface temperature for approximately 169 of the largest inland water bodies in the world. We are now extending this work to generate temperature time-series of all North American inland water bodies that are sufficiently large to be studied using 1km resolution satellite data for the last 3 decades, approximately 268 lakes. These data are then being related to changes in the surface air temperature and compared with regional trends in water surface temperature derived from CMIP5/IPCC model simulations/projections to better predict future temperature changes. We will discuss the available datasets and processing methodologies together with the patterns they reveal based on recent changes in the global warming, with a particular focus on the inland waters of the southwestern USA.

  5. Phenotypic characterization and 16S rDNA identification of culturable non-obligate halophilic bacterial communities from a hypersaline lake, La Sal del Rey, in extreme South Texas (USA)

    PubMed Central

    2012-01-01

    Background La Sal del Rey ("the King's Salt") is one of several naturally-occurring salt lakes in Hidalgo County, Texas and is part of the Lower Rio Grande Valley National Wildlife Refuge. The research objective was to isolate and characterize halophilic microorganisms from La Sal del Rey. Water samples were collected from the lake and a small creek that feeds into the lake. Soil samples were collected from land adjacent to the water sample locations. Sample salinity was determined using a refractometer. Samples were diluted and cultured on a synthetic saline medium to grow halophilic bacteria. The density of halophiles was estimated by viable plate counts. A collection of isolates was selected, gram-stained, tested for catalase, and characterized using API 20E® test strips. Isolates were putatively identified by sequencing the 16S rDNA. Carbon source utilization by the microbial community from each sample site was examined using EcoPlate™ assays and the carbon utilization total activity of the community was determined. Results Results showed that salinity ranged from 4 parts per thousand (ppt) at the lake water source to 420 ppt in water samples taken just along the lake shore. The density of halophilic bacteria in water samples ranged from 1.2 × 102 - 5.2 × 103 colony forming units per ml (cfu ml-1) whereas the density in soil samples ranged from 4.0 × 105 - 2.5 × 106 colony forming units per gram (cfu g-1). In general, as salinity increased the density of the bacterial community decreased. Microbial communities from water and soil samples were able to utilize 12 - 31 carbon substrates. The greatest number of substrates utilized was by water-borne communities compared to soil-based communities, especially at lower salinities. The majority of bacteria isolated were gram-negative, catalase-positive, rods. Biochemical profiles constructed from API 20E® test strips showed that bacterial isolates from low-salinity water samples (4 ppt) showed the greatest

  6. Multi-proxy paleoenvironmental reconstruction of saline lake carbonates: Paleoclimatic and paleogeographic implications (Priabonian-Rupelian, Issirac Basin, SE France)

    NASA Astrophysics Data System (ADS)

    Lettéron, Alexandre; Fournier, François; Hamon, Youri; Villier, Loïc; Margerel, Jean-Pierre; Bouche, Alexandre; Feist, Monique; Joseph, Philippe

    2017-08-01

    A 200-m thick carbonate succession has been deposited in shallow-water, saline lake environments during the Priabonian-Rupelian in the Issirac Basin (South-East France). The palaeoenvironmental and palaeogeographic significance of such saline lake carbonates has been characterized on the basis of a multi-proxy analysis including 1) depositional and diagenetic features, 2) biological components (molluscs, ostracods, benthic foraminifers, characean) and 3) carbon, oxygen and strontium stable isotopes. Biological associations are indicative of dominantly shallow (< 10 m), freshwater to mesohaline (0 to 18‰) environments. The occurrence of evaporites is indicative of periods of hypersalinity. Carbonate production is dominantly associated to microbial activity (planar stromatolites) and micrite precipitation in lakes colonized by macrophyte meadows. The Priabonian-Rupelian carbonates from the Issirac Basin recorded three main cycles of lake transgression, corresponding to the three main sedimentary units (U1, U2 and U3). Relative lake-level, degree of connectivity with surrounding lakes and climate (dry versus humid) are the three key factors controlling the water composition, carbonate production and depositional environments in the Issirac lake. Although the ASCI (Alès-Issirac-Saint-Chaptes) lacustrine system likely represents an athalassic (inland) lake system evolving through times, the stable isotope composition (C, O and Sr) of carbonates strongly suggests the occurrence of transient connections of the ASCI lake water with water bodies influenced by seawater and/or fed with sulfates deriving from Triassic evaporites. The Issirac Basin may be therefore interpreted as a sill area connecting the ASCI lacustrine system with the Rhône valley (Mormoiron and Valence) saline lake systems during maximum flooding periods. Finally, changes in depositional features, biota and stable isotope composition of carbonates in unit U3 suggest a transition from relatively dry to

  7. Insights of Phage-Host Interaction in Hypersaline Ecosystem through Metagenomics Analyses

    PubMed Central

    Motlagh, Amir Mohaghegh; Bhattacharjee, Ananda S.; Coutinho, Felipe H.; Dutilh, Bas E.; Casjens, Sherwood R.; Goel, Ramesh K.

    2017-01-01

    Bacteriophages, as the most abundant biological entities on Earth, place significant predation pressure on their hosts. This pressure plays a critical role in the evolution, diversity, and abundance of bacteria. In addition, phages modulate the genetic diversity of prokaryotic communities through the transfer of auxiliary metabolic genes. Various studies have been conducted in diverse ecosystems to understand phage-host interactions and their effects on prokaryote metabolism and community composition. However, hypersaline environments remain among the least studied ecosystems and the interaction between the phages and prokaryotes in these habitats is poorly understood. This study begins to fill this knowledge gap by analyzing bacteriophage-host interactions in the Great Salt Lake, the largest prehistoric hypersaline lake in the Western Hemisphere. Our metagenomics analyses allowed us to comprehensively identify the bacterial and phage communities with Proteobacteria, Firmicutes, and Bacteroidetes as the most dominant bacterial species and Siphoviridae, Myoviridae, and Podoviridae as the most dominant viral families found in the metagenomic sequences. We also characterized interactions between the phage and prokaryotic communities of Great Salt Lake and determined how these interactions possibly influence the community diversity, structure, and biogeochemical cycles. In addition, presence of prophages and their interaction with the prokaryotic host was studied and showed the possibility of prophage induction and subsequent infection of prokaryotic community present in the Great Salt Lake environment under different environmental stress factors. We found that carbon cycle was the most susceptible nutrient cycling pathways to prophage induction in the presence of environmental stresses. This study gives an enhanced snapshot of phage and prokaryote abundance and diversity as well as their interactions in a hypersaline complex ecosystem, which can pave the way for

  8. Lake

    ERIC Educational Resources Information Center

    Wien, Carol Anne

    2008-01-01

    The lake is blue black and deep. It is a glaciated finger lake, clawed out of rock when ice retracted across Nova Scotia in a northerly direction during the last ice age. The lake is narrow, a little over a mile long, and deep, 90 to 190 feet in places according to local lore, off the charts in others. The author loves to swim there, with a sense…

  9. Assembly-driven community genomics of a hypersaline microbial ecosystem.

    PubMed

    Podell, Sheila; Ugalde, Juan A; Narasingarao, Priya; Banfield, Jillian F; Heidelberg, Karla B; Allen, Eric E

    2013-01-01

    Microbial populations inhabiting a natural hypersaline lake ecosystem in Lake Tyrrell, Victoria, Australia, have been characterized using deep metagenomic sampling, iterative de novo assembly, and multidimensional phylogenetic binning. Composite genomes representing habitat-specific microbial populations were reconstructed for eleven different archaea and one bacterium, comprising between 0.6 and 14.1% of the planktonic community. Eight of the eleven archaeal genomes were from microbial species without previously cultured representatives. These new genomes provide habitat-specific reference sequences enabling detailed, lineage-specific compartmentalization of predicted functional capabilities and cellular properties associated with both dominant and less abundant community members, including organisms previously known only by their 16S rRNA sequences. Together, these data provide a comprehensive, culture-independent genomic blueprint for ecosystem-wide analysis of protein functions, population structure, and lifestyles of co-existing, co-evolving microbial groups within the same natural habitat. The "assembly-driven" community genomic approach demonstrated in this study advances our ability to push beyond single gene investigations, and promotes genome-scale reconstructions as a tangible goal in the quest to define the metabolic, ecological, and evolutionary dynamics that underpin environmental microbial diversity.

  10. Heterotrophic Protists in Hypersaline Microbial Mats and Deep Hypersaline Basin Water Columns

    PubMed Central

    Edgcomb, Virginia P.; Bernhard, Joan M.

    2013-01-01

    Although hypersaline environments pose challenges to life because of the low water content (water activity), many such habitats appear to support eukaryotic microbes. This contribution presents brief reviews of our current knowledge on eukaryotes of water-column haloclines and brines from Deep Hypersaline Anoxic Basins (DHABs) of the Eastern Mediterranean, as well as shallow-water hypersaline microbial mats in solar salterns of Guerrero Negro, Mexico and benthic microbialite communities from Hamelin Pool, Shark Bay, Western Australia. New data on eukaryotic diversity from Shark Bay microbialites indicates eukaryotes are more diverse than previously reported. Although this comparison shows that eukaryotic communities in hypersaline habitats with varying physicochemical characteristics are unique, several groups are commonly found, including diverse alveolates, strameonopiles, and fungi, as well as radiolaria. Many eukaryote sequences (SSU) in both regions also have no close homologues in public databases, suggesting that these environments host unique microbial eukaryote assemblages with the potential to enhance our understanding of the capacity of eukaryotes to adapt to hypersaline conditions. PMID:25369746

  11. Database for Hydrological Time Series of Inland Waters (DAHITI)

    NASA Astrophysics Data System (ADS)

    Schwatke, Christian; Dettmering, Denise

    2016-04-01

    Satellite altimetry was designed for ocean applications. However, since some years, satellite altimetry is also used over inland water to estimate water level time series of lakes, rivers and wetlands. The resulting water level time series can help to understand the water cycle of system earth and makes altimetry to a very useful instrument for hydrological applications. In this poster, we introduce the "Database for Hydrological Time Series of Inland Waters" (DAHITI). Currently, the database contains about 350 water level time series of lakes, reservoirs, rivers, and wetlands which are freely available after a short registration process via http://dahiti.dgfi.tum.de. In this poster, we introduce the product of DAHITI and the functionality of the DAHITI web service. Furthermore, selected examples of inland water targets are presented in detail. DAHITI provides time series of water level heights of inland water bodies and their formal errors . These time series are available within the period of 1992-2015 and have varying temporal resolutions depending on the data coverage of the investigated water body. The accuracies of the water level time series depend mainly on the extent of the investigated water body and the quality of the altimeter measurements. Hereby, an external validation with in-situ data reveals RMS differences between 5 cm and 40 cm for lakes and 10 cm and 140 cm for rivers, respectively.

  12. Vacuolated Beggiatoa-like filaments from different hypersaline environments form a novel genus.

    PubMed

    Hinck, Susanne; Mussmann, Marc; Salman, Verena; Neu, Thomas R; Lenk, Sabine; Beer, Dirk de; Jonkers, Henk M

    2011-12-01

    In this study, members of a specific group of thin (6-14 µm filament diameter), vacuolated Beggiatoa-like filaments from six different hypersaline microbial mats were morphologically and phylogenetically characterized. Therefore, enrichment cultures were established, filaments were stained with fluorochromes to show intracellular structures and 16S rRNA genes were sequenced. Morphological characteristics of Beggiatoa-like filaments, in particular the presence of intracellular vacuoles, and the distribution of nucleic acids were visualized. In the intracellular vacuole nitrate reached concentrations of up to 650 mM. Fifteen of the retrieved 16S rRNA gene sequences formed a monophyletic cluster and were phylogenetically closely related (≥ 94.4% sequence identity). Sequences of known filamentous sulfide-oxidizing genera Beggiatoa and Thioploca that comprise non-vacuolated and vacuolated filaments from diverse habitats clearly delineated from this cluster. The novel monophyletic cluster was furthermore divided into two sub-clusters: one contained sequences originating from Guerrero Negro (Mexico) microbial mats and the other comprised sequences from five distinct Spanish hypersaline microbial mats from Ibiza, Formentera and Lake Chiprana. Our data suggest that Beggiatoa-like filaments from hypersaline environments displaying a thin filament diameter contain nitrate-storing vacuoles and are phylogenetically separate from known Beggiatoa. Therefore, we propose a novel genus for these organisms, which we suggest to name 'Candidatus Allobeggiatoa'.

  13. Organismal and spatial partitioning of energy and macronutrient transformations within a hypersaline mat.

    PubMed

    Mobberley, Jennifer M; Lindemann, Stephen R; Bernstein, Hans C; Moran, James J; Renslow, Ryan S; Babauta, Jerome; Hu, Dehong; Beyenal, Haluk; Nelson, William C

    2017-03-15

    Phototrophic mat communities are model ecosystems for studying energy cycling and elemental transformations because complete biogeochemical cycles occur over millimeter-to-centimeter scales. Characterization of energy and nutrient capture within hypersaline phototrophic mats has focused on specific processes and organisms, however little is known about community-wide distribution of and linkages between these processes. To investigate energy and macronutrient capture and flow through a structured community, the spatial and organismal distribution of metabolic functions within a compact hypersaline mat community from Hot Lake have been broadly elucidated through species-resolved metagenomics and geochemical, microbial diversity, and metabolic gradient measurements. Draft reconstructed genomes of 34 abundant organisms revealed three dominant cyanobacterial populations differentially distributed across the top layers of the mat suggesting niche separation along light and oxygen gradients. Many organisms contained diverse functional profiles, allowing for metabolic response to changing conditions within the mat. Organisms with partial nitrogen and sulfur metabolisms were widespread indicating dependence upon metabolite exchange. In addition, changes in community spatial structure were observed over the diel. These results indicate that organisms within the mat community have adapted to the temporally dynamic environmental gradients in this hypersaline mat through metabolic flexibility and fluid syntrophic interactions, including shifts in spatial arrangements.

  14. The Archaea of a Hypersaline Microbial Mat

    NASA Astrophysics Data System (ADS)

    Robertson, C.; Spear, J. R.; Pace, N. R.

    2006-12-01

    The overarching goal of this work is to describe and understand the organismal composition within the domain Archaea for the microbial ecosystem of a hypersaline microbial mat. Sea salt is crystallized by solar evaporation at North America's largest saltworks, the Exportadora de Sal, in Guerrero Negro, Baja California Sur. Sea water flows through a series of evaporative basins with an increase in salinity until saturation is reached and halite crystallization begins. Several of these ponds are underlined with thick microbial mats. To date, it has not been known what kinds of organisms comprise these complex microbial ecosystems. Here, we report a survey of the stratified microbial communities for the distribution of representatives of Archaea in layers of the mats. This survey uses molecular approaches, based on cloning and sequencing of SSU rRNA genes for phylogenetic analyses, to determine the nature and extent of archaeal diversity that constitute these ecosystems. We compiled an altogether new phylogenetic backbone for the domain Archaea and placed representative sequences from this hypersaline analysis onto that framework. Analyses to date indicate the ubiquitous dominance of uncultured organisms of phylogenetic kinds not generally thought to be associated with hypersaline environments. Collectively, the results indicate that the diversity of life is extensive even in this seemingly inhospitable "extreme" environment.

  15. Use of an Acoustic Doppler Current Profiler (ADCP) to Measure Hypersaline Bidirectional Discharge

    USGS Publications Warehouse

    Johnson, K.K.; Loving, B.L.; ,

    2002-01-01

    The U.S. Geological Survey measures the exchange of flow between the north and south parts of Great Salt Lake, Utah, as part of a monitoring program. Turbidity and bidirectional flow through the breach in the causeway that divides the lake into two parts makes it difficult to measure discharge with conventional streamflow techniques. An acoustic Doppler current profiler (ADCP) can be used to more accurately define the angles of flow and the location of the interface between the layers of flow. Because of the high salinity levels measured in Great Salt Lake (60-280 parts per thousand), special methods had to be developed to adjust ADCP-computed discharges for the increased speed of sound in hypersaline waters and for water entrained at the interface between flow layers.

  16. 46 CFR 11.435 - Service requirements for master of inland steam or motor vessels of any gross tons.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... holding a mate/first class pilot license or MMC endorsement. ... (excluding the Great Lakes) steam or motor vessels of any gross tons is: (a) One year of service as first class pilot (of other than canal and small lakes routes) or mate of Great Lakes or inland steam or motor...

  17. 46 CFR 11.435 - Service requirements for master of inland steam or motor vessels of any gross tons.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... holding a mate/first class pilot license or MMC endorsement. ... (excluding the Great Lakes) steam or motor vessels of any gross tons is: (a) One year of service as first class pilot (of other than canal and small lakes routes) or mate of Great Lakes or inland steam or motor...

  18. 46 CFR 11.435 - Service requirements for master of inland steam or motor vessels of any gross tons.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... holding a mate/first class pilot license or MMC endorsement. ... (excluding the Great Lakes) steam or motor vessels of any gross tons is: (a) One year of service as first class pilot (of other than canal and small lakes routes) or mate of Great Lakes or inland steam or motor...

  19. "The Effect of Alternative Representations of Lake ...

    EPA Pesticide Factsheets

    Lakes can play a significant role in regional climate, modulating inland extremes in temperature and enhancing precipitation. Representing these effects becomes more important as regional climate modeling (RCM) efforts focus on simulating smaller scales. When using the Weather Research and Forecasting (WRF) model to downscale future global climate model (GCM) projections into RCM simulations, model users typically must rely on the GCM to represent temperatures at all water points. However, GCMs have insufficient resolution to adequately represent even large inland lakes, such as the Great Lakes. Some interpolation methods, such as setting lake surface temperatures (LSTs) equal to the nearest water point, can result in inland lake temperatures being set from sea surface temperatures (SSTs) that are hundreds of km away. In other cases, a single point is tasked with representing multiple large, heterogeneous lakes. Similar consequences can result from interpolating ice from GCMs to inland lake points, resulting in lakes as large as Lake Superior freezing completely in the space of a single timestep. The use of a computationally-efficient inland lake model can improve RCM simulations where the input data is too coarse to adequately represent inland lake temperatures and ice (Gula and Peltier 2012). This study examines three scenarios under which ice and LSTs can be set within the WRF model when applied as an RCM to produce 2-year simulations at 12 km gri

  20. Archaeal Communities in a Heterogeneous Hypersaline-Alkaline Soil

    PubMed Central

    Navarro-Noya, Yendi E.; Valenzuela-Encinas, César; Sandoval-Yuriar, Alonso; Jiménez-Bueno, Norma G.; Marsch, Rodolfo

    2015-01-01

    In this study the archaeal communities in extreme saline-alkaline soils of the former lake Texcoco, Mexico, with electrolytic conductivities (EC) ranging from 0.7 to 157.2 dS/m and pH from 8.5 to 10.5 were explored. Archaeal communities in the 0.7 dS/m pH 8.5 soil had the lowest alpha diversity values and were dominated by a limited number of phylotypes belonging to the mesophilic Candidatus Nitrososphaera. Diversity and species richness were higher in the soils with EC between 9.0 and 157.2 dS/m. The majority of OTUs detected in the hypersaline soil were members of the Halobacteriaceae family. Novel phylogenetic branches in the Halobacteriales class were detected in the soil, and more abundantly in soil with the higher pH (10.5), indicating that unknown and uncharacterized Archaea can be found in this soil. Thirteen different genera of the Halobacteriaceae family were identified and were distributed differently between the soils. Halobiforma, Halostagnicola, Haloterrigena, and Natronomonas were found in all soil samples. Methanogenic archaea were found only in soil with pH between 10.0 and 10.3. Retrieved methanogenic archaea belonged to the Methanosarcinales and Methanomicrobiales orders. The comparison of the archaeal community structures considering phylogenetic information (UniFrac distances) clearly clustered the communities by pH. PMID:26074731

  1. Archaeal Communities in a Heterogeneous Hypersaline-Alkaline Soil.

    PubMed

    Navarro-Noya, Yendi E; Valenzuela-Encinas, César; Sandoval-Yuriar, Alonso; Jiménez-Bueno, Norma G; Marsch, Rodolfo; Dendooven, Luc

    2015-01-01

    In this study the archaeal communities in extreme saline-alkaline soils of the former lake Texcoco, Mexico, with electrolytic conductivities (EC) ranging from 0.7 to 157.2 dS/m and pH from 8.5 to 10.5 were explored. Archaeal communities in the 0.7 dS/m pH 8.5 soil had the lowest alpha diversity values and were dominated by a limited number of phylotypes belonging to the mesophilic Candidatus Nitrososphaera. Diversity and species richness were higher in the soils with EC between 9.0 and 157.2 dS/m. The majority of OTUs detected in the hypersaline soil were members of the Halobacteriaceae family. Novel phylogenetic branches in the Halobacteriales class were detected in the soil, and more abundantly in soil with the higher pH (10.5), indicating that unknown and uncharacterized Archaea can be found in this soil. Thirteen different genera of the Halobacteriaceae family were identified and were distributed differently between the soils. Halobiforma, Halostagnicola, Haloterrigena, and Natronomonas were found in all soil samples. Methanogenic archaea were found only in soil with pH between 10.0 and 10.3. Retrieved methanogenic archaea belonged to the Methanosarcinales and Methanomicrobiales orders. The comparison of the archaeal community structures considering phylogenetic information (UniFrac distances) clearly clustered the communities by pH.

  2. Investigations of Methane Production in Hypersaline Environments

    NASA Technical Reports Server (NTRS)

    Bebout, Brad M.

    2015-01-01

    The recent reports of methane in the atmosphere of Mars, as well as the findings of hypersaline paleo-environments on that planet, have underscored the need to evaluate the importance of biological (as opposed to geological) trace gas production and consumption. Methane in the atmosphere of Mars may be an indication of life but might also be a consequence of geologic activity and/or the thermal alteration of ancient organic matter. Hypersaline environments have now been reported to be extremely likely in several locations in our solar system, including: Mars, Europa, and Enceladus. Modern hypersaline microbial mat communities, (thought to be analogous to those present on the early Earth at a period of time when Mars was experiencing very similar environmental conditions), have been shown to produce methane. However, very little is known about the physical and/or biological controls imposed upon the rates at which methane, and other important trace gases, are produced and consumed in these environments. We describe here the results of our investigations of methane production in hypersaline environments, including field sites in Chile, Baja California Mexico, California, USA and the United Arab Emirates. We have measured high concentrations of methane in bubbles of gas produced both in the sediments underlying microbial mats, as well as in areas not colonized by microbial mats in the Guerrero Negro hypersaline ecosystem, Baja California Mexico, in Chile, and in salt ponds on the San Francisco Bay. The carbon isotopic (d13C) composition of the methane in the bubbles exhibited an extremely wide range of values, (ca. -75 per mille ca. -25 per mille). The hydrogen isotopic composition of the methane (d2H) ranged from -60 to -30per mille and -450 to -350per mille. These isotopic values are outside of the range of values normally considered to be biogenic, however incubations of the sediments in contact with these gas bubbles reveals that the methane is indeed being

  3. Substrate limitation for methanogenesis in hypersaline environments.

    PubMed

    Kelley, Cheryl A; Poole, Jennifer A; Tazaz, Amanda M; Chanton, Jeffrey P; Bebout, Brad M

    2012-02-01

    Motivated by the increasingly abundant evidence for hypersaline environments on Mars and reports of methane in its atmosphere, we examined methanogenesis in hypersaline ponds in Baja California Sur, Mexico, and in northern California, USA. Methane-rich bubbles trapped within or below gypsum/halite crusts have δ¹³C values near -40‰. Methane with these relatively high isotopic values would typically be considered thermogenic; however, incubations of crust samples resulted in the biological production of methane with similar isotopic composition. A series of measurements aimed at understanding the isotopic composition of methane in hypersaline systems was therefore undertaken. Methane production rates, as well as the concentrations and isotopic composition of the particulate organic carbon (POC), were measured. Methane production was highest from microbial communities living within gypsum crusts, whereas POC content at gypsum/halite sites was low, generally less than 1% of the total mass. The isotopic composition of the POC ranged from -26‰ to -10‰. To determine the substrates used by the methanogens, ¹³C-labeled methylamines, methanol, acetate, and bicarbonate were added to individual incubation vials, and the methane produced was monitored for ¹³C content. The main substrates used by the methanogens were the noncompetitive substrates, the methylamines, and methanol. When unlabeled trimethylamine (TMA) was added to incubating gypsum/halite crusts in increasing concentrations, the isotopic composition of the methane produced became progressively lower; the lowest methane δ¹³C values occurred when the most TMA was added (1000 μM final concentration). This decrease in the isotopic composition of the methane produced with increasing TMA concentrations, along with the high in situ methane δ¹³C values, suggests that the methanogens within the crusts are operating at low substrate concentrations. It appears that substrate limitation is decreasing

  4. Microbial Fuel Cell as Life Detector: Arsenic Cycling in Hypersaline Environments

    NASA Astrophysics Data System (ADS)

    Miller, L. G.; Blum, J. S.; Oremland, R. S.

    2006-12-01

    Detection of extant life on Mars or Europa is a future goal of exobiology. For the present, biosignatures arising from life in extreme environments on Earth suggest how to search for life elsewhere. One such biosignature is the electrical current derived from the metabolic activity of microorganisms, which may be measured using microbial fuel cells (MFCs). MFCs generate electricity by coupling bacterially mediated redox transformations to electrochemical reactions through a circuit. Our laboratory fuel cell employs solid graphite electrodes and uses a proton exchange membrane to separate anode (anaerobic) and cathode (aerobic) chambers. Mineral salts media are circulated by peristaltic pump through the chambers and through temperature-controlled reservoirs that are sparged with nitrogen (anode) or oxygen (cathode). In experiments with pure cultures, bacteria reduced arsenate to arsenite in the anode chamber, and produced electrical power in the process. Power production was sustained in the MFC only while bacteria were active. An arsenate respiring bacterium, Bacillus selenitireducens, isolated from moderately-hypersaline Mono Lake, CA grew on lactate using arsenate as the electron acceptor and also grew without arsenate, using the anode as the electron acceptor. Power densities (per unit area of anode surface) of 60 μW m-2 were achieved during growth without arsenate. Less power (3 μW m-2) was produced when arsenate was available because arsenate acted as an alternate electron acceptor to the anode. Another arsenate respiring bacterium, strain SLAS-1, isolated from extremely-hypersaline Searles Lake, CA respired lactate and reduced arsenate in the MFC, albeit more slowly. An arsenite oxidizing bacterium, Alkalilimnicola ehrlichii, isolated from Mono Lake will also be tested for its ability to generate electricity before proceeding to an examination of biocurrent production using natural sediments and waters from Mono Lake and Searles Lake.

  5. Lake Enriquillo, Dominican Republic

    NASA Image and Video Library

    2017-08-15

    Lake Enriquillo is a hypersaline lake in the Dominican Republic. In 2004, the lake covered an area of 164 square kilometers; by 2011, it had doubled in size and grown to 350 km2, inundating farmland and homes. Various reasons for the flooding include increases in rainfall; increase of sediments going into the lake, raising the lakebed; and milder temperatures, reducing surface evaporation. The lake is home to the largest population of American crocodiles in the Caribbean. The images were acquired October 26, 2003 and June 10, 2017, cover an area of 22.7 by 45.4 km, and are located at 18.5 degrees north, 71.6 degrees west. An image of Lake Enriquillo taken in 2003 is available at https://photojournal.jpl.nasa.gov/catalog/PIA21815

  6. Development of a Halotolerant Community in the St. Lucia Estuary (South Africa) during a Hypersaline Phase

    PubMed Central

    Carrasco, Nicola K.; Perissinotto, Renzo

    2012-01-01

    Background The St. Lucia Estuary, Africa's largest estuarine lake, is currently experiencing unprecedented freshwater deprivation which has resulted in a northward gradient of drought effects, with hypersaline conditions in its northern lakes. Methodology/Principal Findings This study documents the changes that occurred in the biotic communities at False Bay from May 2010 to June 2011, in order to better understand ecosystem functioning in hypersaline habitats. Few zooplankton taxa were able to withstand the harsh environmental conditions during 2010. These were the flatworm Macrostomum sp., the harpacticoid copepod Cletocamptus confluens, the cyclopoid copepod Apocyclops cf. dengizicus and the ciliate Fabrea cf. salina. In addition to their exceptional salinity tolerance, they were involved in a remarkably simple food web. In June 2009, a bloom of an orange-pigmented cyanobacterium (Cyanothece sp.) was recorded in False Bay and persisted uninterruptedly for 18 months. Stable isotope analysis suggests that this cyanobacterium was the main prey item of F. cf. salina. This ciliate was then consumed by A. cf. dengizicus, which in turn was presumably consumed by flamingos as they flocked in the area when the copepods attained swarming densities. On the shore, cyanobacteria mats contributed to a population explosion of the staphylinid beetle Bledius pilicollis. Although zooplankton disappeared once salinities exceeded 130, many taxa are capable of producing spores or resting cysts to bridge harsh periods. The hypersaline community was disrupted by heavy summer rains in 2011, which alleviated drought conditions and resulted in a sharp increase in zooplankton stock and diversity. Conclusions/Significance Despite the current freshwater deprivation crisis, the False Bay region has shown to be resilient, harboring a unique biodiversity with species that are capable of enduring harsh environmental conditions. However, further freshwater deprivation may extend beyond the

  7. Groundwater-Lake Interaction in the Dead Sea Area

    NASA Astrophysics Data System (ADS)

    Kiro, Y.; Weinstein, Y.; Starinsky, A.; Yechieli, Y.

    2011-12-01

    The Dead Sea hypersaline water system is unique in terms of its unusual geochemical composition, rapid lake level changes and water composition of the brines discharging along its shoreline. The Dead Sea can be used as a natural lab for studying groundwater-seawater interaction and saline water hydrological circulation along the aquifer-sea boundary. It provides an opportunity to follow the geochemical processes along a flow path from the lake into the aquifer and back into the lake. The lake level has been dropping since the 1960's due to human interference in its water budget, reaching a rate of 1 m/yr in recent years. Saline water circulation in coastal aquifers may be a major process that governs trace element mass balances in coastal areas. This study uses radium isotopes in order to quantify the lake water circulation in the Dead Sea aquifer. There are four naturally-occurring radium isotopes, with half-lives ranging from 3.7 days to 1600 years which are chain products of uranium and thorium isotopes. Radium isotopes are usually enriched in saline groundwater and therefore are good candidates for estimating seawater or hypersaline lake water circulation in the aquifer. Compared to most natural water bodies, the Dead Sea is extremely enriched in radium and barium, where both 226Ra and 228Ra activities and Ba concentration (145, 1-2 dpm/L and 5 mg/L, respectively) are 2-3 orders of magnitude higher than in ocean water, whereas the salinity of the Dead Sea is only 10 times higher. Circulated Dead Sea water in the aquifer contains decreased concentrations of 226Ra (60 dpm/L), Ba (1.5 mg/L), Sr (300 relative to 340 mg/L in the Dead Sea) and Sulfate (250 relative to 392 mg/L). We suggest that the low 226Ra and Ba concentrations are due to precipitation of barite and celestine from the supersaturated Dead Sea water on entering the aquifer. 228Ra and the shorter-lived 224Ra and 223Ra, which have much lower activities in the Dead Sea (up to 1.8, 3 and 0.8 dpm

  8. Diversity of Arsenate Respiratory Reductase Genes Along Gradients of Arsenate and Arsenite Within Hypersaline, Alkaline Sediments

    NASA Astrophysics Data System (ADS)

    Saltikov, C. W.; Nilsen, J.; Oremland, R. S.; Kulp, T. R.; Hoeft, S. E.; Miller, L. G.; Switzer Blum, J.; Baesman, S.; Han, S.; Lanoil, B.

    2005-12-01

    There are several soda lakes in western United States that contain high arsenic concentrations (up to 4 mM total As). Interestingly, these lakes have high rates of anaerobic arsenate reduction, which is catalyzed by arsenate respiring prokaryotes. Several cultured arsenate respiring prokaryotes have been shown to respire and reduce arsenate via a membrane-associated enzyme, ArrA. This enzyme is present in many diverse arsenate respiring prokaryotes. To investigate arsenate respiring microbial communities within these extreme environments, we used functional gene analysis to detect the presence, abundance, and diversity of the arrA gene in core samples collected from two arsenic enriched, hypersaline, alkaline lakes, Mono Lake and Searles Lake. Each sample exhibited concentration gradients for dissolved arsenic species and oxygen. Porewater arsenite concentration increased with depth and was correlated with oxygen depletion. To investigate the depth dependency of the arrA gene in these core samples we utilized the Malasarn et al. (2004) polymerase chain reaction (PCR) primers to detect a partial arrA gene fragment in nucleic acids extracted from sediment samples. The arrA gene fragment was detected only in the top 1-2 cm of the Mono Lake core and no detection was observed in the Searles Lake homogenized core. After the primers were redesigned to include the nucleotide codon bias for haloalkaliphilic archaea ( Halobacterium), the arrA gene fragments could be detected at each depth interval throughout the Mono Lake core and in the homogenized core of Searles Lake. Work is currently focused on characterizing the diversity and abundance of the arrA gene fragments obtained in each core sample and at different depths. Although no haloalkaliphilic arsenate respiring archaea have been isolated to date, these results suggest that the arrA gene fragments detected in these soda lakes may be of archaeal origins.

  9. Sensitivity of a GCM simulation to inclusion of inland water surfaces

    SciTech Connect

    Bonan, G.B.

    1995-11-01

    A land surface model that includes a subgrid parameterization for inland water (lake, swamp, marsh) was coupled to a modified version of the NCAR CCM2. The coupled model was run for 5 yr with and without inland water subgrid points to determine the importance of inland water for global climate simulation. In July, the inclusion of these water bodies resulted in a spatially consistent signal in which high inland water regions were 2{degrees}-3{degrees}C cooler, had increased latent heat flux (10-45 W m{sup -2}), and decreased sensible heat flux (5-30 W m{sup -2}) compared to the simulation without these water bodies. These changes were statistically significant in the lake region of northwest Canada, the Great Lakes region of North America, the swamp and marsh region of the Siberian lowlands, and the lake region of East Africa, but were not significantly different in the swamp and marsh region of Finland and northwest Russia. The effect on Northern Hemisphere January air temperature was difficult to interpret due to large interannual variability. In tropical lake regions (East Africa), the response to lakes was less in the rainy season (January) than in the dry season (July). Precipitation was unchanged in both months except for the Great Lakes region where precipitation increased in January. These changes in temperature, precipitation, and surface fluxes were consistent with mesoscale modeling studies of the effects of lakes on climate and tended to bring the model closer to observations. In particular, the summer cooling in North America helped reduce a large warm temperature bias in the model, but did not eliminate the bias. The lakes had little effect on atmospheric moisture, radiation, or zonal circulation. These results show that subgrid-scale inland water bodies can be successfully added to global land surface models for use with GCMs. 35 refs., 7 figs., 7 tabs.

  10. High genetic diversity and novelty in planktonic protists inhabiting inland and coastal high salinity water bodies.

    PubMed

    Triadó-Margarit, Xavier; Casamayor, Emilio O

    2013-07-01

    We analyzed the genetic diversity (18S rRNA gene) of planktonic microbial eukaryotes in 34 different coastal and inland saline ponds. A wide range of environmental conditions was covered with up to 30-fold differences in salinity concentrations (12.5-384 g L(-1)), and in situ temperatures (1.3-37.5 °C), and three orders of magnitude in the trophic status (i.e. chlorophyll a < 0.1 to >50 mg L(-1)). Geographically distant sites were studied with contrasting salt origins, and different temporal patterns of wetting and drying. The genetic diversity was high, far beyond the few groups traditionally considered as high salinity-adapted, with sequences spread throughout eight high-rank taxonomic groups and 27 eukaryal classes. The novelty level was extremely high, with 10% of the whole dataset showing < 90% identity to any previously reported sequence in GenBank. Opisthokonta and Rhizaria contained the highest novelty and Chlorophyta and Alveolata the lowest. Low identity sequences were observed both in coastal and inland sites and at lower and at higher salinities, although the degree of novelty was higher in the hypersaline waters (> 6.5% salinity). Overall, this study shows important gaps in the current knowledge about protists inhabiting continental (hyper)saline water bodies, highlighting the need for future, more detailed investigations. © 2013 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  11. Analysis of fae and fhcD genes in Mono Lake, California.

    PubMed

    Nercessian, Olivier; Kalyuzhnaya, Marina G; Joye, Samantha B; Lidstrom, Mary E; Chistoserdova, Ludmila

    2005-12-01

    Genes for two enzymes of the tetrahydromethanopterin-linked C(1) transfer pathway (fae and fhcD) were detected in hypersaline, hyperalkaline Mono Lake (California), via PCR amplification and analysis. Low diversity for fae and fhcD was noted, in contrast to the diversity previously detected in a freshwater lake, Lake Washington (Washington).

  12. Inland notches micromorphology

    NASA Astrophysics Data System (ADS)

    Brook, Anna; Ben-Binyamin, Atzmon; Shtober-Zisu, Nurit

    2017-04-01

    Inland notches are well known phenomenon in Israel and can be found mostly along the mountainous backbone, developed in hard limestone or dolomite rocks within the Mediterranean climate zone and up to the desert fringe. LiDAR technology presents an opportunity to study the fine scale rock surface within the notch and its texture patterns. De-trending of the LiDAR reconstructed DEM to a local trend, surface roughness, was achieved by fitting a normalized surface to all measured ground points within the roughness neighborhood. Micro-topography plays an important role for modelling geomorphology dynamics, resulting in improved estimates for micro stream lines network and topographic erosion as well as mineral accumulation or deposition. Clearly, dissolution occurs whenever rock and solvent meet; thus water and moisture's crucial role in the decay of carbonate rocks results in texture and roughness variability. Study aims is to generate high resolution normalized DEM models using a terrestrial LiDAR, redefining the texture and roughness within the notch while assessing weathering processes caused by water. Plan curvature is the second derivative of slope taken perpendicular to its direction. It influences convergence and divergence of flow and it emphasizes the ridges and valleys across the surface. Concaved classified areas were tested against all planar curvature areas to distinguish them as unique areas based on their texture co-occurrence measures (GLCM). Overall negative curvature pixels show poor separability, in both TD and JM separation tests, while classes of curvature degree describe a positive trend showing medium and high concavity as unique areas. Study aims to link classified areas as the basic micro infrastructure for water flow, potential runoff flow and further accumulation of minerals. On the other hand, positive values of Plan curvature present the convexity of rock surface to imply diverging flow, thus describing the watershed line within the micro

  13. Inland Waters and the North American Carbon Cycle

    NASA Astrophysics Data System (ADS)

    Butman, D. E.; Striegl, R. G.; Stackpoole, S. M.; del Giorgio, P.; Prairie, Y.; Pilcher, D.; Raymond, P. A.; Alcocer, J.; Paz, F.

    2016-12-01

    Inland aquatic ecosystems process, store, and release carbon to the atmosphere and coastal margins. The form of this carbon is a function of terrestrial and aquatic primary and secondary production, the weathering of materials in soils and subsurface environments, the hydrologic controls on the movement of carbon from land to inland waters, and the connectivity between streams, rivers, lakes, reservoirs and groundwater. The 2007 1st State of the Carbon Cycle reported fluxes for the continental United States (CONUS) only. Streams and rivers exported 30-40 Tg C yr-1 to coastal environments, and 17-25 Tg C yr-1 were buried in lake and reservoir sediments. Remarkably, the 2007 report did not quantify gas emissions, which represent over half of the total carbon fluxes through inland water in the US. Current research has shown that 71-149 Tg C yr-1 exits freshwater systems either through atmospheric emissions of carbon dioxide or as inorganic and organic carbon fluxes to the coast from the CONUS. These estimates did not include the Laurentian Great Lakes. Variation in the magnitude of these fluxes across regions of the CONUS has been linked to differences in precipitation and terrestrial net ecosystem production. Similar comprehensive assessments have not been done for Canada or Mexico. Here we provide, as part of the 2nd State of the Carbon Cycle report, estimates for the river coastal export and vertical emissions of carbon from inland waters of North America, and report major data gaps, and weaknesses in methodologies. These findings stress that strong international partnerships are needed to improve assessment, monitoring, and modeling of human impacts on the magnitude and timing of aquatic fluxes in the future.

  14. Temperature Trends in Montane Lakes

    NASA Astrophysics Data System (ADS)

    Melack, J. M.; Sadro, S.; Jellison, R.

    2014-12-01

    Long-term temperature trends in lakes integrate hydrological and meteorological factors. We examine temperature trends in a small montane lake with prolonged ice-cover and large seasonal snowfall and in a large saline lake. Emerald Lake, located in the Sierra Nevada (California), is representative of high-elevation lakes throughout the region. No significant trend in outflow temperature was apparent from 1991to 2012. Snowfall in the watershed accounted for 93% of the variability in average summer lake temperatures. Mono Lake (California) lies in a closed, montane basin and is hypersaline and monomictic or meromictic. Temperature profiles have been collected from 1982 to 2010. In the upper water column, the July-August-September water temperatures increased 0.8-1.0°C over the 29 years. This rate of warming is less than published estimates based on satellite-derived skin temperatures and will discussed in the context of general limnological interpretation of temperature trends.

  15. Viruses Occur Incorporated in Biogenic High-Mg Calcite from Hypersaline Microbial Mats

    PubMed Central

    De Wit, Rutger; Gautret, Pascale; Bettarel, Yvan; Roques, Cécile; Marlière, Christian; Ramonda, Michel; Nguyen Thanh, Thuy; Tran Quang, Huy; Bouvier, Thierry

    2015-01-01

    Using three different microscopy techniques (epifluorescence, electronic and atomic force microscopy), we showed that high-Mg calcite grains in calcifying microbial mats from the hypersaline lake “La Salada de Chiprana”, Spain, contain viruses with a diameter of 50–80 nm. Energy-dispersive X-ray spectrometer analysis revealed that they contain nitrogen and phosphorus in a molar ratio of ~9, which is typical for viruses. Nucleic acid staining revealed that they contain DNA or RNA. As characteristic for hypersaline environments, the concentrations of free and attached viruses were high (>1010 viruses per g of mat). In addition, we showed that acid treatment (dissolution of calcite) resulted in release of viruses into suspension and estimated that there were ~15 × 109 viruses per g of calcite. We suggest that virus-mineral interactions are one of the possible ways for the formation of nano-sized structures often described as “nanobacteria” and that viruses may play a role in initiating calcification. PMID:26115121

  16. 75 FR 11870 - Inland Waterways Users Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-12

    ... Transportation System (IMTS) Investment Strategy Team activities, as well as the status of the funding for inland navigation projects and studies and the status of the Inland Waterways Trust Fund. FOR FURTHER INFORMATION...

  17. Pyruvate: A key Nutrient in Hypersaline Environments?

    PubMed

    Oren, Aharon

    2015-08-07

    Some of the most commonly occurring but difficult to isolate halophilic prokaryotes, Archaea as well as Bacteria, require or prefer pyruvate as carbon and energy source. The most efficient media for the enumeration and isolation of heterotrophic prokaryotes from natural environments, from freshwater to hypersaline, including the widely used R2A agar medium, contain pyruvate as a key ingredient. Examples of pyruvate-loving halophiles are the square, extremely halophilic archaeon Haloquadratum walsbyi and the halophilic gammaproteobacterium Spiribacter salinus. However, surprisingly little is known about the availability of pyruvate in natural environments and about the way it enters the cell. Some halophilic Archaea (Halorubrum saccharovorum, Haloarcula spp.) partially convert sugars and glycerol to pyruvate and other acids (acetate, lactate) which are excreted to the medium. Pyruvate formation from glycerol was also shown during a bloom of halophilic Archaea in the Dead Sea. However, no pyruvate transporters were yet identified in the genomes of halophilic Archaea, and altogether, our understanding of pyruvate transport in the prokaryote world is very limited. Therefore, the preference for pyruvate by fastidious and often elusive halophiles and the empirically proven enhanced colony recovery on agar media containing pyruvate are still poorly understood.

  18. Pyruvate: A key Nutrient in Hypersaline Environments?

    PubMed Central

    Oren, Aharon

    2015-01-01

    Some of the most commonly occurring but difficult to isolate halophilic prokaryotes, Archaea as well as Bacteria, require or prefer pyruvate as carbon and energy source. The most efficient media for the enumeration and isolation of heterotrophic prokaryotes from natural environments, from freshwater to hypersaline, including the widely used R2A agar medium, contain pyruvate as a key ingredient. Examples of pyruvate-loving halophiles are the square, extremely halophilic archaeon Haloquadratum walsbyi and the halophilic gammaproteobacterium Spiribacter salinus. However, surprisingly little is known about the availability of pyruvate in natural environments and about the way it enters the cell. Some halophilic Archaea (Halorubrum saccharovorum, Haloarcula spp.) partially convert sugars and glycerol to pyruvate and other acids (acetate, lactate) which are excreted to the medium. Pyruvate formation from glycerol was also shown during a bloom of halophilic Archaea in the Dead Sea. However, no pyruvate transporters were yet identified in the genomes of halophilic Archaea, and altogether, our understanding of pyruvate transport in the prokaryote world is very limited. Therefore, the preference for pyruvate by fastidious and often elusive halophiles and the empirically proven enhanced colony recovery on agar media containing pyruvate are still poorly understood. PMID:27682096

  19. Hypersalinity drives physiological and morphological changes in Limia perugiae (Poeciliidae)

    PubMed Central

    Tello, Oscar; Krieger, Jonathan; Marmolejo, Arlen; Weaver, Kathleen F.; Garcia, Jerome V.; Cruz, Alexander

    2016-01-01

    ABSTRACT A fundamental question in biology is how an organism's morphology and physiology are shaped by its environment. Here, we evaluate the effects of a hypersaline environment on the morphology and physiology of a population of livebearing fish in the genus Limia (Poeciliidae). We sampled from two populations of Limia perugiae (one freshwater and one hypersaline) in the southwest Dominican Republic. We evaluated relative abundance of osmoregulatory proteins using western blot analyses and used a geometric morphometric approach to evaluate fine-scale changes to size and shape. Our data show that gill tissue isolated from hypersaline fish contained approximately two and a half times higher expression of Na+/K+ ATPase proteins. We also show evidence for mitochondrial changes within the gills, with eight times more complex I and four times higher expression of ATP synthase within the gill tissue from the hypersaline population. The energetic consequences to Limia living in saline and hypersaline environments may be a driver for phenotypic diversity, reducing the overall body size and changing the relative size and shape of the head, as well as impeding the growth of secondary sex features among the males. PMID:27402966

  20. Lake Chad, Chad, Africa

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Once a great inland lake, Lake Chad (13.0N, 14.0E) in the Sahara Desert at the intersection of the African nations of Chad, Niger, Nigeria and Cameroon, is now in decline. The larger northern lobe is almost totally dry and slowly filling in with encroaching sand dunes. The southern lobe, still retains some water in the lower center but the water surface area is less than 2000 square kilometers and sand dunes are filling in the north end.

  1. Cyanotoxin occurrence associated with cyanoHAB events on an inland reservoir

    EPA Science Inventory

    A monitoring approach combining wet chemistry and high frequency (HF) water quality sensors was employed to improve our understanding of the ecology of an inland reservoir with a history of cyanoHAB events. The study was conducted with samples collected from Lake Harsha, is a mul...

  2. Cyanotoxin occurrence associated with cyanoHAB events on an inland reservoir

    EPA Science Inventory

    A monitoring approach combining wet chemistry and high frequency (HF) water quality sensors was employed to improve our understanding of the ecology of an inland reservoir with a history of cyanoHAB events. The study was conducted with samples collected from Lake Harsha, is a mul...

  3. Culture-independent approaches for studying viruses from hypersaline environments.

    PubMed

    Santos, Fernando; Yarza, Pablo; Parro, Víctor; Meseguer, Inmaculada; Rosselló-Móra, Ramon; Antón, Josefa

    2012-03-01

    Hypersaline close-to-saturation environments harbor an extremely high concentration of virus-like particles, but the number of haloviruses isolated so far is still very low. Haloviruses can be directly studied from natural samples by using different culture-independent techniques that include transmission electron microscopy, pulsed-field gel electrophoresis, and different metagenomic approaches. Here, we review the findings of these studies, with a main focus on the metagenomic approaches. The analysis of bulk viral nucleic acids directly retrieved from the environment allows estimations of viral diversity, activity, and dynamics and tentative host assignment. Results point to a diverse and active viral community in constant interplay with its hosts and to a "hypersalineness" quality common to viral assemblages present in hypersaline environments that are thousands of kilometers away from each other.

  4. Microbial diversity in hypersaline wastewater: the example of tanneries.

    PubMed

    Lefebvre, O; Vasudevan, N; Thanasekaran, K; Moletta, R; Godon, J J

    2006-12-01

    In contrast to conventional wastewater treatment plants and saline environments, little is known regarding the microbial diversity of hypersaline wastewater. In this study, the microbial communities of a hypersaline tannery effluent, and those of three treatment systems operating with the tannery effluent, were investigated using 16S rDNA phylogenetic markers. The comparative analysis of 377 bacterial sequences revealed the high diversity of this type of hypersaline environment, clustering within 193 phylotypes (> or = 97% similarity) and covering 14 of the 52 divisions of the bacterial domain, i.e. Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria, Chlorobi, Planctomycetes, Spirochaetes, Synergistes, Chloroflexi, Thermotogae, Verrucomicrobia, OP3, OP11 and TM7. Most of the phylotypes were related to halophilic and pollutant-degrading bacteria. Using statistical analysis, the diversity of this type of environment was compared to that of other environmental samples selected on the basis of their salinity, oxygen content and organic load.

  5. Biomass production from inland brines

    SciTech Connect

    Reach, C.D. Jr.

    1985-01-01

    The feasibility of utilizing inland saline waters to produce biomass through the application of marine aquaculture was investigated. From available data, the diatom Phaeodactylum tricornutum and the crustacea Artemia salina were selected as the experimental marine organisms. The proposed diatom served to establish primary productivity and concurrently provide a food source for the herbivorus crustacea. The objective of the first phase research was to investigate the ability of P. tricornutum and A. salina to survive in the inland saline environment. Clarified activated sludge and anaerobic digester effluents were evaluated as nutrient sources for the diatom cultures. Experimental results indicated that diatom and crustacea growth in the inland brine was equivalent to control cultures utilizing seawater. Wastewater effluents were successful as nutrient sources for the diatom cultures. Bioassay experiments conducted with petroleum related brines yielded mixed results respect to the survival and growth of the P. tricornutum and A. salina organisms. A second series of experiments involved cholornaphthalene, chlorophenanthene, and chlorophenanthrene, and chloroanthracene as the experimental hydrocarbons. Results of the diatom studies show chloroanthracene to induce toxic effects at a concentration of 500 ug/L. Artemia studies showed no acutely toxic effects relative to the test hydrocarbons at 50 and 100 ug/L.

  6. Landsat analysis of lake quality

    NASA Technical Reports Server (NTRS)

    Scarpace, F. L.; Fisher, L. T.; Holmquist, K. W.

    1979-01-01

    The trophic status of a number of inland lakes in Wisconsin has been assessed. The feasibility of using both photographic and digital representations of Landsat imagery was investigated during the lake classification project. The result of the investigation has been a semi-automatic data acquisition and handling system which, in conjunction with an analytical categorization scheme, can be used to classify all the significant lakes in the state.

  7. The enigma of prokaryotic life in deep hypersaline anoxic basins.

    PubMed

    van der Wielen, Paul W J J; Bolhuis, Henk; Borin, Sara; Daffonchio, Daniele; Corselli, Cesare; Giuliano, Laura; D'Auria, Giuseppe; de Lange, Gert J; Huebner, Andreas; Varnavas, Sotirios P; Thomson, John; Tamburini, Christian; Marty, Danielle; McGenity, Terry J; Timmis, Kenneth N

    2005-01-07

    Deep hypersaline anoxic basins in the Mediterranean Sea are a legacy of dissolution of ancient subterranean salt deposits from the Miocene period. Our study revealed that these hypersaline basins are not biogeochemical dead ends, but support in situ sulfate reduction, methanogenesis, and heterotrophic activity. A wide diversity of prokaryotes was observed, including a new, abundant, deeply branching order within the Euryarchaeota. Furthermore, we demonstrated the presence of a unique, metabolically active microbial community in the Discovery basin, which is one of the most extreme terrestrial saline environments known, as it is almost saturated with MgCl2 (5 M).

  8. amoA-encoding archaea and thaumarchaeol in the lakes on the northeastern Qinghai-Tibetan Plateau, China

    PubMed Central

    Yang, Jian; Jiang, Hongchen; Dong, Hailiang; Wang, Huanye; Wu, Geng; Hou, Weiguo; Liu, Weiguo; Zhang, Chuanlun; Sun, Yongjuan; Lai, Zhongping

    2013-01-01

    All known ammonia-oxidizing archaea (AOA) belong to the phylum Thaumarchaeota within the domain Archaea. AOA possess the diagnostic amoA gene (encoding the alpha subunit of ammonia monooxygenase) and produce lipid biomarker thaumarchaeol. Although the abundance and diversity of amoA gene-encoding archaea (AEA) in freshwater lakes have been well-studied, little is known about AEA ecology in saline/hypersaline lakes. In this study, the distribution of the archaeal amoA gene and thaumarchaeol were investigated in nine Qinghai–Tibetan lakes with a salinity range from freshwater to salt-saturation (salinity: 325 g L-1). The results showed that the archaeal amoA gene was present in hypersaline lakes with salinity up to 160 g L-1. The archaeal amoA gene diversity in Tibetan lakes was different from those in other lakes worldwide, suggesting Tibetan lakes (high elevation, strong ultraviolet, and dry climate) may host a unique AEA population of different evolutionary origin from those in other lakes. Thaumarchaeol was present in all of the studied hypersaline lakes, even in those where no AEA amoA gene was observed. Future research is needed to determine the ecological function of AEA and possible sources of thaumarchaeol in the Qinghai–Tibetan hypersaline lakes. PMID:24273535

  9. Establishment of microbial eukaryotic enrichment cultures from a chemically stratified antarctic lake and assessment of carbon fixation potential.

    PubMed

    Dolhi, Jenna M; Ketchum, Nicholas; Morgan-Kiss, Rachael M

    2012-04-20

    Lake Bonney is one of numerous permanently ice-covered lakes located in the McMurdo Dry Valleys, Antarctica. The perennial ice cover maintains a chemically stratified water column and unlike other inland bodies of water, largely prevents external input of carbon and nutrients from streams. Biota are exposed to numerous environmental stresses, including year-round severe nutrient deficiency, low temperatures, extreme shade, hypersalinity, and 24-hour darkness during the winter (1). These extreme environmental conditions limit the biota in Lake Bonney almost exclusively to microorganisms (2). Single-celled microbial eukaryotes (called "protists") are important players in global biogeochemical cycling (3) and play important ecological roles in the cycling of carbon in the dry valley lakes, occupying both primary and tertiary roles in the aquatic food web. In the dry valley aquatic food web, protists that fix inorganic carbon (autotrophy) are the major producers of organic carbon for organotrophic organisms (4, 2). Phagotrophic or heterotrophic protists capable of ingesting bacteria and smaller protists act as the top predators in the food web (5). Last, an unknown proportion of the protist population is capable of combined mixotrophic metabolism (6, 7). Mixotrophy in protists involves the ability to combine photosynthetic capability with phagotrophic ingestion of prey microorganisms. This form of mixotrophy differs from mixotrophic metabolism in bacterial species, which generally involves uptake dissolved carbon molecules. There are currently very few protist isolates from permanently ice-capped polar lakes, and studies of protist diversity and ecology in this extreme environment have been limited (8, 4, 9, 10, 5). A better understanding of protist metabolic versatility in the simple dry valley lake food web will aid in the development of models for the role of protists in the global carbon cycle. We employed an enrichment culture approach to isolate potentially

  10. [Hygiene problems in inland and sea navigation].

    PubMed

    Goethe, H

    1983-09-01

    Both waste and sewage disposal are ubiquitous problems which have also affected navigation. Shipping is a very important transport carrier on a worldwide basis which together with the fishing industry employs roughly two million people. The problems associated with waste and sewage disposal obviously present a severe hazard to the coastal areas, narrow sea basins and, in particular, to inland and open-sea waterways. These problems are particularly alarming in large sea-ports, docks without outfall etc. The reduction of the crews aboard the ships operated by the industialised countries has helped to quantitatively ease the problem of waste and sewage disposal caused by the crews. However, passenger steamers with high waste and sewage volumes cause considerable nuisance in small harbours and the same holds for the disposal of technical waste products from ships such as dunnage packing material, ropes, plastic material, oil, etc. The quantity of waste water aboard a sea-going vessel including that from the toilets, washrooms, galley, and cleaning is rather considerable and is estimated at 300 litres per person and day under tropical climates. The volume of waste varies greatly and depends mainly on the type of material used aboard as mentioned above. Passenger liners with a very high volume of kitchen refuse and other solid waste give rise to specially insidious problems. In the past, sea-going vessels as well as ships employed in inland navigation used to throw overboard any type of refuse and sewage. However, during the last few decades the port authorities and also governments have introduced local and national regulations ruling that waste may no longer be thrown into harbour basins, but must be collected and disposed of on shore. Most ships have complied with these provisions, but some of them kept the collected refuse aboard and disposed of it on the open sea outside the harbours. International agreements on the prohibition of emptying oil and oil

  11. Sunlight-induced carbon dioxide emissions from inland waters

    NASA Astrophysics Data System (ADS)

    Koehler, Birgit; Landelius, Tomas; Weyhenmeyer, Gesa A.; Machida, Nanako; Tranvik, Lars J.

    2014-07-01

    The emissions of carbon dioxide (CO2) from inland waters are substantial on a global scale. Yet the fundamental question remains open which proportion of these CO2 emissions is induced by sunlight via photochemical mineralization of dissolved organic carbon (DOC), rather than by microbial respiration during DOC decomposition. Also, it is unknown on larger spatial and temporal scales how photochemical mineralization compares to other C fluxes in the inland water C cycle. We combined field and laboratory data with atmospheric radiative transfer modeling to parameterize a photochemical rate model for each day of the year 2009, for 1086 lakes situated between latitudes from 55°N to 69°N in Sweden. The sunlight-induced production of dissolved inorganic carbon (DIC) averaged 3.8 ± 0.04 g C m-2 yr-1, which is a flux comparable in size to the organic carbon burial in the lake sediments. Countrywide, 151 ± 1 kt C yr-1 was produced by photochemical mineralization, corresponding to about 12% of total annual mean CO2 emissions from Swedish lakes. With a median depth of 3.2 m, the lakes were generally deep enough that incoming, photochemically active photons were absorbed in the water column. This resulted in a linear positive relationship between DIC photoproduction and the incoming photon flux, which corresponds to the absorbed photons. Therefore, the slope of the regression line represents the wavelength- and depth-integrated apparent quantum yield of DIC photoproduction. We used this relationship to obtain a first estimate of DIC photoproduction in lakes and reservoirs worldwide. Global DIC photoproduction amounted to 13 and 35 Mt C yr-1 under overcast and clear sky, respectively. Consequently, these directly sunlight-induced CO2 emissions contribute up to about one tenth to the global CO2 emissions from lakes and reservoirs, corroborating that microbial respiration contributes a substantially larger share than formerly thought, and generate annual C fluxes similar in

  12. Metagenomic and lipid analyses reveal a diel cycle in a hypersaline microbial ecosystem

    PubMed Central

    Andrade, Karen; Logemann, Jörn; Heidelberg, Karla B; Emerson, Joanne B; Comolli, Luis R; Hug, Laura A; Probst, Alexander J; Keillar, Angus; Thomas, Brian C; Miller, Christopher S; Allen, Eric E; Moreau, John W; Brocks, Jochen J; Banfield, Jillian F

    2015-01-01

    Marine microbial communities experience daily fluctuations in light and temperature that can have important ramifications for carbon and nutrient cycling. Elucidation of such short time scale community-wide dynamics is hindered by system complexity. Hypersaline aquatic environments have lower species richness than marine environments and can be well-defined spatially, hence they provide a model system for diel cycle analysis. We conducted a 3-day time series experiment in a well-defined pool in hypersaline Lake Tyrrell, Australia. Microbial communities were tracked by combining cultivation-independent lipidomic, metagenomic and microscopy methods. The ratio of total bacterial to archaeal core lipids in the planktonic community increased by up to 58% during daylight hours and decreased by up to 32% overnight. However, total organism abundances remained relatively consistent over 3 days. Metagenomic analysis of the planktonic community composition, resolved at the genome level, showed dominance by Haloquadratum species and six uncultured members of the Halobacteriaceae. The post 0.8 μm filtrate contained six different nanohaloarchaeal types, three of which have not been identified previously, and cryo-transmission electron microscopy imaging confirmed the presence of small cells. Notably, these nano-sized archaea showed a strong diel cycle, with a pronounced increase in relative abundance over the night periods. We detected no eukaryotic algae or other photosynthetic primary producers, suggesting that carbon resources may derive from patchily distributed microbial mats at the sediment-water interface or from surrounding land. Results show the operation of a strong community-level diel cycle, probably driven by interconnected temperature, light abundance, dissolved oxygen concentration and nutrient flux effects. PMID:25918833

  13. Partial reline of Inland`s No. 7 blast furnace

    SciTech Connect

    Lowrance, K.F. II; Johansson, J.; Carter, W.L.

    1995-10-01

    The background for the decision to partially reline No. 7 blast furnace that would achieve the same results as a complete reline is discussed. This approach was designed to reduce actual downtime on the furnace at a critical production period. Areas of work included the hearth, stack, stoves, gas cleaning and furnace top. Highlights of the project execution were: schedules; blowdown; salamander tap; quench; dig out/descale; scaffolding used; and brick installation. The furnace was blown-in 29 days after the blowdown and producing in excess of 9,000 tons/day after 12 days of operation. Inland has adopted a new definition for establishing campaign life based on refractory wear that includes a hearth monitoring system.

  14. Winter Lake Breezes near the Great Salt Lake

    NASA Astrophysics Data System (ADS)

    Crosman, Erik T.; Horel, John D.

    2016-05-01

    Case studies of lake breezes during wintertime cold air pools in Utah's Salt Lake Valley are examined. While summer breezes originating from the Great Salt Lake are typically deeper, of longer duration, and have higher wind speeds than winter breezes, the rate of inland penetration and cross-frontal temperature differences can be higher during the winter. The characteristics of winter breezes and the forcing mechanisms controlling them (e.g., snow cover, background flow, vertical stability profile, clouds, lake temperature, lake sheltering, and drainage pooling) are more complex and variable than those evident in summer. During the afternoon in the Salt Lake Valley, these lake breezes can lead to elevated pollution levels due to the transport of fine particle pollutants from over the Great Salt Lake, decreased vertical mixing depth, and increased vertical stability.

  15. 77 FR 44222 - Inland Waterways Users Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-27

    ... Department of the Army; Corps of Engineers Inland Waterways Users Board AGENCY: Department of the Army, U.S.... Name of Committee: Inland Waterways Users Board (Board). Date: August 29, 2012. Location: The Sheraton... and the FY 2013 budget, status of the Olmsted Locks and Dam Project, and the Board will consider its...

  16. 78 FR 72070 - Inland Waterways Users Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-02

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF DEFENSE Department of the Army; Corps of Engineers Inland Waterways Users Board AGENCY: Department of the Army, U.S.... Name of Committee: Inland Waterways Users Board (Board). Date: January 14, 2014. Location: Meeting at...

  17. Employing the Disadvantaged: Inland Steel's Experience.

    ERIC Educational Resources Information Center

    Campbell, Ralph

    1969-01-01

    Among the various approaches used by the Inland Steel Company in training ghetto youth for jobs, greatest promise has been shown by the Work Experience and Training Program initiated in 1965 at the Joseph T. Ryerson and Son plant, an Inland subsidiary located in the Lawndale (West Side) area of Chicago near the scene of the 1966 riots. Results…

  18. Employing the Disadvantaged: Inland Steel's Experience.

    ERIC Educational Resources Information Center

    Campbell, Ralph

    1969-01-01

    Among the various approaches used by the Inland Steel Company in training ghetto youth for jobs, greatest promise has been shown by the Work Experience and Training Program initiated in 1965 at the Joseph T. Ryerson and Son plant, an Inland subsidiary located in the Lawndale (West Side) area of Chicago near the scene of the 1966 riots. Results…

  19. DAHITI - An Innovative Approach for Estimating Water Level Time Series over Inland Water using Multi-Mission Satellite Altimetry

    NASA Astrophysics Data System (ADS)

    Schwatke, Christian; Dettmering, Denise

    2016-04-01

    Satellite altimetry has been designed for sea level monitoring over open ocean areas. However, for some years, this technology has also been used to retrieve water levels from lakes, reservoirs, rivers, wetlands and in general any inland water body. In this contribution, a new approach for the estimation of inland water level time series is presented. The method is the basis for the computation of time series of rivers and lakes available through the web service 'Database for Hydrological Time Series over Inland Water' (DAHITI). It is based on an extended outlier rejection and a Kalman filter approach incorporating cross-calibrated multi-mission altimeter data from Envisat, ERS-2, Jason-1, Jason-2, Topex/Poseidon, and SARAL/AltiKa, including their uncertainties. The new approach yields RMS differences with respect to in situ data between 4 cm and 36 cm for lakes and 8 cm and 114 cm for rivers, respectively. Within this presentation, the new approach will be introduced and examples for water level time series for a variety of lakes and rivers will be shown featuring different characteristics such as shape, lake extent, river width, and data coverage. A comprehensive validation is performed by comparisons with in situ gauge data and results from external inland altimeter databases.

  20. DAHITI - an innovative approach for estimating water level time series over inland waters using multi-mission satellite altimetry

    NASA Astrophysics Data System (ADS)

    Schwatke, C.; Dettmering, D.; Bosch, W.; Seitz, F.

    2015-10-01

    Satellite altimetry has been designed for sea level monitoring over open ocean areas. However, for some years, this technology has also been used to retrieve water levels from reservoirs, wetlands and in general any inland water body, although the radar altimetry technique has been especially applied to rivers and lakes. In this paper, a new approach for the estimation of inland water level time series is described. It is used for the computation of time series of rivers and lakes available through the web service "Database for Hydrological Time Series over Inland Waters" (DAHITI). The new method is based on an extended outlier rejection and a Kalman filter approach incorporating cross-calibrated multi-mission altimeter data from Envisat, ERS-2, Jason-1, Jason-2, TOPEX/Poseidon, and SARAL/AltiKa, including their uncertainties. The paper presents water level time series for a variety of lakes and rivers in North and South America featuring different characteristics such as shape, lake extent, river width, and data coverage. A comprehensive validation is performed by comparisons with in situ gauge data and results from external inland altimeter databases. The new approach yields rms differences with respect to in situ data between 4 and 36 cm for lakes and 8 and 114 cm for rivers. For most study cases, more accurate height information than from other available altimeter databases can be achieved.

  1. Spatially-resolved stable isotope analysis of a hypersaline microbial mat

    NASA Astrophysics Data System (ADS)

    Moran, J.; Cory, A. B.; Lindemann, S. R.; Fredrickson, J. K.

    2012-12-01

    Hot Lake is a hypersaline, meromictic lake located in north-central Washington. High rates of evapotranspiration coupled with its location in an endorrheic basin contribute to the lake's high salinity. The predominant dissolved salt is magnesium sulfate; hypolimnion waters may seasonally exceed 2 M magnesium sulfate concentrations. In addition to extreme salinity, horizons within the lake seasonally exceed 50 °C, in part due to the enhanced light absorption by magnesium sulfate-saturated water. Despite extreme and highly variable seasonal conditions (salinity, temperature, photon flux), dense benthic microbial mats composed of cyanobacteria and bacterial heterotroph populations develop annually at the lake. These mats may exceed 5 mm in thickness and display stratification observable by eye associated with dominant bacterial phototrophic pigments. Typical mat stratification includes an orange surface layer followed by green and purple layers at increasing depth into the mat. Carbonates including aragonite and magnesite are observed within the mat and their formation is likely induced or influenced by microbial activities. While not exclusively limited to the green stratum in the mat, maximum carbonate content is within this layer. We are exploring the role Hot Lake's microbial mats play in carbon cycling within the system. Namely, we seek to understand the rates of carbon accumulation in the mat and associated sediments and the various forms this carbon takes (organic or inorganic species). We are assessing mat development, community composition, and carbon accumulation in pre-cleaned devices installed at the lake as they are colonized by native mat. We are using laser ablation isotope ratio mass spectrometry (LA-IRMS) to provide spatially-resolved stable isotope analysis of mat cross-sections. Currently, this technique permits isotope analysis at the 50 μm scale, and can provide multiple isotope analyses within the thickness of each major layer of the mat. We

  2. Large contribution to inland water CO2 and CH4 emissions from very small ponds

    NASA Astrophysics Data System (ADS)

    Holgerson, Meredith A.; Raymond, Peter A.

    2016-03-01

    Inland waters are an important component of the global carbon cycle. Although they contribute to greenhouse gas emissions, estimates of carbon processing in these waters are uncertain. The global extent of very small ponds, with surface areas of less than 0.001 km2, is particularly difficult to map, resulting in their exclusion from greenhouse gas budget estimates. Here we combine estimates of the lake and pond global size distribution, gas exchange rates, and measurements of carbon dioxide and methane concentrations from 427 lakes and ponds ranging in surface area from 2.5 m2 to 674 km2. We estimate that non-running inland waters release 0.583 Pg C yr-1. Very small ponds comprise 8.6% of lakes and ponds by area globally, but account for 15.1% of CO2 emissions and 40.6% of diffusive CH4 emissions. In terms of CO2 equivalence, the ratio of CO2 to CH4 flux increases with surface area, from about 1.5 in very small ponds to about 19 in large lakes. The high fluxes from very small ponds probably result from shallow waters, high sediment and edge to water volume ratios, and frequent mixing. These attributes increase CO2 and CH4 supersaturation in the water and limit efficient methane oxidation. We conclude that very small ponds represent an important inland water carbon flux.

  3. Transboundary fisheries science: Meeting the challenges of inland fisheries management in the 21st century

    USGS Publications Warehouse

    Midway, Stephen R.; Wagner, Tyler; Zydlewski, Joseph D.; Irwin, Brian J.; Paukert, Craig P.

    2016-01-01

    Managing inland fisheries in the 21st century presents several obstacles, including the need to view fisheries from multiple spatial and temporal scales, which usually involves populations and resources spanning sociopolitical boundaries. Though collaboration is not new to fisheries science, inland aquatic systems have historically been managed at local scales and present different challenges than in marine or large freshwater systems like the Laurentian Great Lakes. Therefore, we outline a flexible strategy that highlights organization, cooperation, analytics, and implementation as building blocks toward effectively addressing transboundary fisheries issues. Additionally, we discuss the use of Bayesian hierarchical models (within the analytical stage), due to their flexibility in dealing with the variability present in data from multiple scales. With growing recognition of both ecological drivers that span spatial and temporal scales and the subsequent need for collaboration to effectively manage heterogeneous resources, we expect implementation of transboundary approaches to become increasingly critical for effective inland fisheries management.

  4. Wet Tropospheric Corrections over Inland Water- Getting Ready for Sentinel-3

    NASA Astrophysics Data System (ADS)

    Fernandes, M. Joana; Lazaro, Clara

    2015-12-01

    This study addresses the problems associated to the retrieval of the wet tropospheric correction (WTC) for Sentinel-3 over inland water regions. Based on the experience acquired with the development of algorithms to improve the WTC retrieval over the open and coastal ocean, applied to the main altimetric missions, techniques for the estimation of improved WTC for Sentinel-3 over inland waters are being developed at the University of Porto (U.Porto). The potential of these techniques to generate continuous altimeter profiles over inland waters are illustrated with Envisat data over Lake Victoria (Africa). First results show that improved continuous WTC can be obtained, preserving the good MWR values, leading to a decrease in the water surface anomaly variance both with respect to the baseline MWR-derived WTC and ERA Interim model.

  5. Water: Wisconsin lakes, streams and wetlands

    EPA Science Inventory

    Wisconsin has a tremendous diversity of aquatic habitat: headwater streams, large rivers, inland lakes, and two Great Lakes. Knowing the fundamentals of aquatic ecosystem science is critical to understand how these ecosystems function and to predict how they will respond to human...

  6. 27 CFR 9.83 - Lake Erie.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Colden, New York, exactly 12 statute miles inland from any point on the shore of Lake Erie. (3) The... 1:250,000 (1956, revised 1972); (3) “Erie,” scale 1:250,000 (1959, revised 1972); and (4) “Buffalo... on the islands of Lake Erie across the States of New York, Pennsylvania, and Ohio. The...

  7. Water: Wisconsin lakes, streams and wetlands

    EPA Science Inventory

    Wisconsin has a tremendous diversity of aquatic habitat: headwater streams, large rivers, inland lakes, and two Great Lakes. Knowing the fundamentals of aquatic ecosystem science is critical to understand how these ecosystems function and to predict how they will respond to human...

  8. 33 CFR 162.120 - Harbors on Lake Michigan.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Harbors on Lake Michigan. 162.120...) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.120 Harbors on Lake Michigan... City, Indiana; St. Joseph, South Haven, Saugatuck, Holland (Lake Macatawa), Grand Haven, Muskegon...

  9. 40 CFR 35.1605-2 - Freshwater lake.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Freshwater lake. 35.1605-2 Section 35.1605-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... Lakes § 35.1605-2 Freshwater lake. Any inland pond, reservoir, impoundment, or other similar body of...

  10. 40 CFR 35.1605-2 - Freshwater lake.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Freshwater lake. 35.1605-2 Section 35.1605-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... Lakes § 35.1605-2 Freshwater lake. Any inland pond, reservoir, impoundment, or other similar body of...

  11. 33 CFR 162.120 - Harbors on Lake Michigan.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Harbors on Lake Michigan. 162.120...) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.120 Harbors on Lake Michigan... City, Indiana; St. Joseph, South Haven, Saugatuck, Holland (Lake Macatawa), Grand Haven, Muskegon...

  12. 33 CFR 162.120 - Harbors on Lake Michigan.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Harbors on Lake Michigan. 162.120...) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.120 Harbors on Lake Michigan... City, Indiana; St. Joseph, South Haven, Saugatuck, Holland (Lake Macatawa), Grand Haven, Muskegon...

  13. 40 CFR 35.1605-2 - Freshwater lake.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Freshwater lake. 35.1605-2 Section 35.1605-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... Lakes § 35.1605-2 Freshwater lake. Any inland pond, reservoir, impoundment, or other similar body of...

  14. 40 CFR 35.1605-2 - Freshwater lake.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Freshwater lake. 35.1605-2 Section 35.1605-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... Lakes § 35.1605-2 Freshwater lake. Any inland pond, reservoir, impoundment, or other similar body of...

  15. 40 CFR 35.1605-2 - Freshwater lake.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Freshwater lake. 35.1605-2 Section 35... STATE AND LOCAL ASSISTANCE Cooperative Agreements for Protecting and Restoring Publicly Owned Freshwater Lakes § 35.1605-2 Freshwater lake. Any inland pond, reservoir, impoundment, or other similar body of...

  16. Ophiuroids Discovered in the Middle Triassic Hypersaline Environment

    PubMed Central

    Salamon, Mariusz A.; Niedźwiedzki, Robert; Lach, Rafał; Brachaniec, Tomasz; Gorzelak, Przemysław

    2012-01-01

    Echinoderms have long been considered to be one of the animal phyla that is strictly marine. However, there is growing evidence that some recent species may live in either brackish or hypersaline environments. Surprisingly, discoveries of fossil echinoderms in non-(open)marine paleoenvironments are lacking. In Wojkowice Quarry (Southern Poland), sediments of lowermost part of the Middle Triassic are exposed. In limestone layer with cellular structures and pseudomorphs after gypsum, two dense accumulations of articulated ophiuroids (Aspiduriella similis (Eck)) were documented. The sediments with ophiuroids were formed in environment of increased salinity waters as suggested by paleontological, sedimentological, petrographical and geochemical data. Discovery of Triassic hypersaline ophiuroids invalidates the paleontological assumption that fossil echinoderms are indicators of fully marine conditions. Thus caution needs to be taken when using fossil echinoderms in paleoenvironmental reconstructions. PMID:23185442

  17. Culture-Independent Approaches for Studying Viruses from Hypersaline Environments

    PubMed Central

    Santos, Fernando; Yarza, Pablo; Parro, Víctor; Meseguer, Inmaculada; Rosselló-Móra, Ramon

    2012-01-01

    Hypersaline close-to-saturation environments harbor an extremely high concentration of virus-like particles, but the number of haloviruses isolated so far is still very low. Haloviruses can be directly studied from natural samples by using different culture-independent techniques that include transmission electron microscopy, pulsed-field gel electrophoresis, and different metagenomic approaches. Here, we review the findings of these studies, with a main focus on the metagenomic approaches. The analysis of bulk viral nucleic acids directly retrieved from the environment allows estimations of viral diversity, activity, and dynamics and tentative host assignment. Results point to a diverse and active viral community in constant interplay with its hosts and to a “hypersalineness” quality common to viral assemblages present in hypersaline environments that are thousands of kilometers away from each other. PMID:22247131

  18. Isolated history of the coastal plant Lathyrus japonicus (Leguminosae) in Lake Biwa, an ancient freshwater lake

    PubMed Central

    Ohtsuki, Tatsuo; Kaneko, Yuko; Setoguchi, Hiroaki

    2011-01-01

    Background and aims Lake Biwa is one of the world's few ancient lakes. Formed ∼4 million years ago, the lake harbours many coastal species that commonly inhabit seashores. The beach pea Lathyrus japonicus is a typical coastal species of this freshwater lake, but its inland populations are faced with the threat of extinction. Here, we investigated the phylogeographical and population structures of both inland and coastal populations of L. japonicus. We also elucidated the historical isolation of the Lake Biwa population. Methodology In total, 520 individuals from 50 L. japonicus populations were sampled throughout the species distribution in Japan. Chloroplast haplotyping using intergenic spacers psbA–trnH and atpI–atpH was performed to investigate the phylogeographical structure as well as the genetic diversity of L. japonicus. Six nuclear microsatellite markers were also used to analyse the population structure. Principal results Population structure analyses of chloroplast DNA (cpDNA) and nuclear DNA (nDNA) identified inland and coastal groups. Based on the genetic differentiation, inland populations exhibited a single cpDNA haplotype and significantly lower values of HS, AR and FIS than coastal populations. In addition to the presence of a bottleneck, the lack of gene flow among inland populations was supported by estimates of recent migration rates between subpopulations. Conclusions Our data revealed that inland populations have been isolated in Lake Biwa as ‘landlocked’ populations since the predecessor lake was isolated from sea. This was also seen in a previous study of Calystegia soldanella. However, the high genetic differentiation, accompanied by a lack of gene flow among the Lake Biwa populations (according to the BAYESASS+ analysis), contradicts the results with C. soldanella. We conclude that because of the presence of a bottleneck and low genetic diversity of the inland populations, self-sustaining population persistence may be difficult in

  19. An Investigation of Summertime Inland Water Body Temperatures in California and Nevada (USA): Recent Trends and Future Projections

    NASA Astrophysics Data System (ADS)

    Healey, Nathan; Hook, Simon; Piccolroaz, Sebastiano; Toffolon, Marco; Radocinski, Robert

    2016-04-01

    Inland water body temperature has been identified as an ideal indicator of potential climate change. Understanding inland water body temperature trends is important for forecasting impacts to limnological, biological, and hydrological resources. Many inland water bodies are situated in remote locations with incomplete data records of in-situ monitoring or lack in-situ observations altogether. Thus, the utilization of satellite data is essential for understanding the behavior of global inland water body temperatures. Part of this research provides an analysis of summertime (July-September) temperature trends in the largest California/Nevada (USA) inland water bodies between 1991 and 2015. We examine satellite temperature retrievals from ATSR (ATSR-1, ATSR-2, AATSR), MODIS (Terra and Aqua), and VIIRS sensors. Our findings indicate that inland water body temperatures in the western United States were rapidly warming between 1991 and 2009, but since then trends have been decreasing. This research also includes implementation of a model called air2water to predict future inland water body surface temperature through the sole input of air temperature. Using projections from CMIP5-CCSM4 output, our model indicates that Lake Tahoe (USA) is expected to experience an increase of roughly 3 °C by 2100.

  20. Plumbing the global carbon cycle: Integrating inland waters into the terrestrial carbon budget

    USGS Publications Warehouse

    Cole, J.J.; Prairie, Y.T.; Caraco, N.F.; McDowell, W.H.; Tranvik, L.J.; Striegl, R.G.; Duarte, C.M.; Kortelainen, Pirkko; Downing, J.A.; Middelburg, J.J.; Melack, J.

    2007-01-01

    Because freshwater covers such a small fraction of the Earth's surface area, inland freshwater ecosystems (particularly lakes, rivers, and reservoirs) have rarely been considered as potentially important quantitative components of the carbon cycle at either global or regional scales. By taking published estimates of gas exchange, sediment accumulation, and carbon transport for a variety of aquatic systems, we have constructed a budget for the role of inland water ecosystems in the global carbon cycle. Our analysis conservatively estimates that inland waters annually receive, from a combination of background and anthropogenically altered sources, on the order of 1.9 Pg C y-1 from the terrestrial landscape, of which about 0.2 is buried in aquatic sediments, at least 0.8 (possibly much more) is returned to the atmosphere as gas exchange while the remaining 0.9 Pg y-1 is delivered to the oceans, roughly equally as inorganic and organic carbon. Thus, roughly twice as much C enters inland aquatic systems from land as is exported from land to the sea. Over prolonged time net carbon fluxes in aquatic systems tend to be greater per unit area than in much of the surrounding land. Although their area is small, these freshwater aquatic systems can affect regional C balances. Further, the inclusion of inland, freshwater ecosystems provides useful insight about the storage, oxidation and transport of terrestrial C, and may warrant a revision of how the modern net C sink on land is described. ?? 2007 Springer Science+Business Media, LLC.

  1. Spatial and Temporal Patterns of Mercury Accumulation in Lacustrine Sediments Across the Laurentian Great Lakes Region

    EPA Science Inventory

    Data from 103 sediment cores from the Great Lakes and inland lakes of the Great Lakes airshed were compiled to examine and provide a synthesis of patterns of historical and recent changes in mercury (Hg) deposition. Limited data from the lower Laurentian Great Lakes shows a lega...

  2. Spatial and Temporal Patterns of Mercury Accumulation in Lacustrine Sediments Across the Laurentian Great Lakes Region

    EPA Science Inventory

    Data from 103 sediment cores from the Great Lakes and inland lakes of the Great Lakes airshed were compiled to examine and provide a synthesis of patterns of historical and recent changes in mercury (Hg) deposition. Limited data from the lower Laurentian Great Lakes shows a lega...

  3. Kalman filter approach for estimating water level time series over inland water using multi-mission satellite altimetry

    NASA Astrophysics Data System (ADS)

    Schwatke, C.; Dettmering, D.; Bosch, W.; Seitz, F.

    2015-05-01

    Satellite altimetry has been designed for sea level monitoring over open ocean areas. However, since some years, this technology is also used for observing inland water levels of lakes and rivers. In this paper, a new approach for the estimation of inland water level time series is described. It is used for the computation of time series available through the web service "Database for Hydrological Time Series over Inland Water" (DAHITI). The method is based on a Kalman filter approach incorporating multi-mission altimeter observations and their uncertainties. As input data, cross-calibrated altimeter data from Envisat, ERS-2, Jason-1, Jason-2, Topex/Poseidon, and SARAL/AltiKa are used. The paper presents water level time series for a variety of lakes and rivers in North and South America featuring different characteristics such as shape, lake extent, river width, and data coverage. A comprehensive validation is performed by comparison with in-situ gauge data and results from external inland altimeter databases. The new approach yields RMS differences with respect to in-situ data between 4 and 38 cm for lakes and 12 and 139 cm for rivers, respectively. For most study cases, more accurate height information than from available other altimeter data bases can be achieved.

  4. High Frequency monitoring of cyanoHABs and cyanotoxin production to characterize periods of greatest risk on an inland reservoir

    EPA Science Inventory

    A monitoring approach combining wet chemistry and high frequency (HF) water quality sensors has been employed to improve our understanding of the ecology of an inland reservoir with a history of cyanoHAB events. Lake Harsha is a multi-use reservoir managed by the USACE in southwe...

  5. High Frequency monitoring of cyanoHABs and cyanotoxin production to characterize periods of greatest risk on an inland reservoir

    EPA Science Inventory

    A monitoring approach combining wet chemistry and high frequency (HF) water quality sensors has been employed to improve our understanding of the ecology of an inland reservoir with a history of cyanoHAB events. Lake Harsha is a multi-use reservoir managed by the USACE in southwe...

  6. The operational use of Landsat for lake quality assessment

    NASA Technical Reports Server (NTRS)

    Scarpace, F. L.; Fisher, L. T.

    1980-01-01

    A cooperative program between the Wisconsin Department of Natural Resources and the University of Wisconsin for the assessment, with Landsat data, of the trophic status of all the significant inland lakes in Wisconsin is described. The analysis technique is a semiautomatic data acquisition and handling system which, in conjunction with an analytical categorization scheme, can be used for classifying inland lakes into one of seven categories of eutrophication and one of four problem types.

  7. Remote measurement and monitoring of inland water heights using multi-mission satellite radar altimetry

    NASA Astrophysics Data System (ADS)

    Benveniste, Jerome

    The effective management of the Earth's inland water is a major challenge facing scientists and governments worldwide. However, whilst demand for this often scarce resource continues to grow, the number and distribution of in-situ hydrological gauge stations is steadily falling and many catchments basins in the developing world are now entirely ungauged. Over the past few years research has been undertaken into a spacebased technique which can remotely measure river and lake heights using data from the series of satellite radar altimeters, originally designed to measure the height of the Earth's oceans. Results over inland water were initially confined to a handful of very large lakes, where the water surface resembled the ocean sufficiently well to allow existing processing techniques to retrieve meaningful measurements. This capability has now been transformed by the development of echo processing techniques which allow that part of the returned signal originating from inland water to be separated from the return from the surrounding terrain. This has extended the scope of this technique to monitoring thousands of river and lake heights worldwide, with the access to more than a decade of historical data now permitting analysis of trends and identification of climate signatures. This paper presents analyses of 15 years of altimeter data using results from hundreds of time series from ERS-2, EnviSat, TOPEX and Jason-1 to demonstrate the effectiveness of this technique in monitoring river and lake heights on a continental scale. The extension of this technique to near real time monitoring using data from the Envisat RA-2 is also presented. The results illustrate the current capability and future potential of this approach to derive a global picture of the Earth's inland water resources and to identify both climate signatures and regions where human usage is depleting the resource beyond its capacity to recharge.

  8. 46 CFR 11.450 - Tonnage limitations and qualifying requirements for endorsements as master or mate of Great Lakes...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Tonnage limitations and qualifying requirements for endorsements as master or mate of Great Lakes and inland vessels of not more than 200 gross tons. 11.450... and qualifying requirements for endorsements as master or mate of Great Lakes and inland vessels of...

  9. 46 CFR 11.450 - Tonnage limitations and qualifying requirements for endorsements as master or mate of Great Lakes...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Tonnage limitations and qualifying requirements for endorsements as master or mate of Great Lakes and inland vessels of less than 200 GRT. 11.450 Section 11.450... limitations and qualifying requirements for endorsements as master or mate of Great Lakes and inland vessels...

  10. 46 CFR 11.450 - Tonnage limitations and qualifying requirements for endorsements as master or mate of Great Lakes...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Tonnage limitations and qualifying requirements for endorsements as master or mate of Great Lakes and inland vessels of not more than 200 gross tons. 11.450... and qualifying requirements for endorsements as master or mate of Great Lakes and inland vessels of...

  11. 46 CFR 11.450 - Tonnage limitations and qualifying requirements for endorsements as master or mate of Great Lakes...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... endorsements as master or mate of Great Lakes and inland vessels of not more than 200 gross tons. 11.450... and qualifying requirements for endorsements as master or mate of Great Lakes and inland vessels of... master or mate of vessels of not more than 200 gross tons are issued in 50 ton increments based on...

  12. 77 FR 69447 - Inland Waterways Users Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-19

    ... investment recommendations, along with updates of the Inland Marine Transportation System (IMTS) Levels of... Road, Casey Building, Alexandria, ] Virginia 22315-3868; Ph: 703-428-6438. SUPPLEMENTARY INFORMATION...

  13. 76 FR 11216 - Inland Waterways Users Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-01

    ... studies and the status of the Inland Waterways Trust Fund, the funding status for Fiscal Year (FY) 2011...) Investment Strategy report recommendations, as well as be updated on the work being performed by the...

  14. Tree Guidelines for Inland Empire Communities

    Treesearch

    E.G. McPherson; J.R. Simpson; P.J. Peper; Q. Xiao; D.R. Pittenger; D.R. Hodel

    2001-01-01

    Communities in the Inland Empire region of California contain over 8 million people, or about 25% of the state’s population. The region’s inhabitants derive great benefit from trees because compared to coastal areas, the summers are hotter and air pollution levels are higher. The region’s climate is still mild enough to grow a diverse mix of trees. The Inland Empire’s...

  15. 33 CFR 162.140 - Connecting waters from Lake Huron to Lake Erie; miscellaneous rules.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Connecting waters from Lake Huron to Lake Erie; miscellaneous rules. 162.140 Section 162.140 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND...

  16. 33 CFR 162.140 - Connecting waters from Lake Huron to Lake Erie; miscellaneous rules.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; miscellaneous rules. 162.140 Section 162.140 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND...

  17. Organic volatile sulfur compounds in inland aquatic systems

    SciTech Connect

    Richards, S.R.

    1991-01-01

    The speciation, concentration, and fluxes of organic volatile sulfur compounds (VSCs) in a wide variety of inland aquatic systems wee studied. Dissolved VSCs were sparged from water samples, trapped cryogenically, and quantified by gas chromatograph equipped with a flame photometric detector. Species detected and mean surface water concentrations were: carbonyl sulfide (COS), 0.091-7.6 nM; methanethiol (MSH), undetected-180 nM; dimethyl sulfide (DMS), 0.48-1290 nM; carbon disulfide (CS[sub 2]), undetected-69 nM; dimethyl disulfide (DMDS), undetected-68 nM. The range in surface water concentrations of over five orders of magnitude was influenced principally by lake depth and sulfate concentration ([SO[sub 4][sup 2[minus

  18. Effects of selenite on Microcystis aeruginosa: Growth, microcystin production and its relationship to toxicity under hypersalinity and copper sulfate stresses.

    PubMed

    Zhou, Chuanqi; Huang, Jung-Chen; Liu, Fang; He, Shengbing; Zhou, Weili

    2017-04-01

    Se laden freshwater algae that enter the Salton Sea with river water pose ecorisks to wildlife in the lake by transferring selenium (Se) to higher trophic levels. The aim of this study was to investigate impacts of Se on Microcystis aeruginosa, widely distributed in freshwater bodies, and its relationship with toxicity, such as microcystins and Se residues. When supplied with selenite, the 96 h-IC50 was calculated 2.60 mg Se/L. However, these inhibitory effects did not extend to microcystin production, and the extracellular fraction significantly increased with selenite as well as sulfate. As M. aeruginosa assimilated selenite very efficiently, 97% of the removed Se was through accumulation, compared to 3% via volatilization, raising a concern about ecotoxicity caused by the remaining Se in the algae. The XAS analysis suggests the dominant Se species accumulated in the algal cells was elemental Se (81%), which is relatively nonbioavailable to aquatic organisms. We further investigated the potential fate of Se carried into the Salton Sea by M. aeruginosa with river water. Under hypersalinity stress, the biomass Se and intracellular microcystins were released and reduced by 47% and 74%, respectively, resulting in the increasing levels of Se and microcystins in the water column. CuSO4 was then applied as an algaecide to prevent M. aeruginosa from entering the lake. The results indicate a similar response to that under hypersalinity stress: the volatilization process was blocked and the Se and microcystins were released from the damaged algal cells in the presence of CuSO4, further raising toxicity levels by 8% and 60%, respectively, in the water column within 24 h. Overall, the coexistence of selenite and M. aeruginosa in river waters might negatively impact aquatic ecosystems of the Salton Sea and further research is required on how to harvest Se from M. aeruginosa to protect local wildlife. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Sulfur cycling and methanogenesis primarily drive microbial colonization of the highly sulfidic Urania deep hypersaline basin.

    PubMed

    Borin, Sara; Brusetti, Lorenzo; Mapelli, Francesca; D'Auria, Giuseppe; Brusa, Tullio; Marzorati, Massimo; Rizzi, Aurora; Yakimov, Michail; Marty, Danielle; De Lange, Gert J; Van der Wielen, Paul; Bolhuis, Henk; McGenity, Terry J; Polymenakou, Paraskevi N; Malinverno, Elisa; Giuliano, Laura; Corselli, Cesare; Daffonchio, Daniele

    2009-06-09

    Urania basin in the deep Mediterranean Sea houses a lake that is >100 m deep, devoid of oxygen, 6 times more saline than seawater, and has very high levels of methane and particularly sulfide (up to 16 mM), making it among the most sulfidic water bodies on Earth. Along the depth profile there are 2 chemoclines, a steep one with the overlying oxic seawater, and another between anoxic brines of different density, where gradients of salinity, electron donors and acceptors occur. To identify and differentiate the microbes and processes contributing to the turnover of organic matter and sulfide along the water column, these chemoclines were sampled at a high resolution. Bacterial cell numbers increased up to a hundredfold in the chemoclines as a consequence of elevated nutrient availability, with higher numbers in the upper interface where redox gradient was steeper. Bacterial and archaeal communities, analyzed by DNA fingerprinting, 16S rRNA gene libraries, activity measurements, and cultivation, were highly stratified and metabolically more active along the chemoclines compared with seawater or the uniformly hypersaline brines. Detailed analysis of 16S rRNA gene sequences revealed that in both chemoclines delta- and epsilon-Proteobacteria, predominantly sulfate reducers and sulfur oxidizers, respectively, were the dominant bacteria. In the deepest layers of the basin MSBL1, putatively responsible for methanogenesis, dominated among archaea. The data suggest that the complex microbial community is adapted to the basin's extreme chemistry, and the elevated biomass is driven largely by sulfur cycling and methanogenesis.

  20. Spatial distribution of Chloroflexus-like bacteria in the hypersaline artificial microbial mat

    NASA Astrophysics Data System (ADS)

    Bachar, A.; Polerecky, L.; Vamvakopoulos, K.; de Beer, D.; Jonkers, H. M.

    An artificial microbial mat grown in a mesocosm originated from the Hypersaline Lake of La Salada de Chiprana NE Spain was examined with respect to its organism s spatial distribution via high resolution methods A special attention was given to the elucidative Chloroflexus -like bacteria on which spatial distribution data is not available We have characterized this thick 1cm and developed mat for photopigments HPLC and obtained the general pigment distribution pattern Furthermore fiberoptic and photosynthetic microsensor measurements gave inner light attenuations and flux rates of oxygen within the different layers respectively Using fluorescence and spectral imaging we were able to detect characteristic pigmentation in the different layers FISH probes targeting Chloroflexus -like bacteria confirmed the visualization techniques and showed a single hybridized layer below the cyanobacterial layer as did the HPLC fiberoptic microsensor and fluorescence imaging We conclude that Chloroflexus -like bacteria are located below the cyanobacterial layer and above the purple sulfur bacteria and for the firs time we are able to show it by different independent state of the art techniques These approaches can be important for rapid community investigations within a millimeter scale microniches

  1. Nutrient, sulfur and carbon dynamics in a hypersaline lagoon

    NASA Astrophysics Data System (ADS)

    Cotner, James B.; Suplee, Michael W.; Chen, Nai Wei; Shormann, David E.

    2004-04-01

    We measured benthic and water column fluxes in a hypersaline coastal system (Baffin Bay, Texas) in 1996-1997, a period of decreasing salinity (increased freshwater input) and turbidity. Salinity decreased from a mean of 60 to 32 practical salinity units (psu) and turbidity decreased from a mean of 78 to 25 NTU over the study period. Associated with hydrological changes, there were important changes in nutrient fluxes and metabolism. There was a shift of total respiration from the water column to the sediments and an increased amount of the benthic metabolism (2-67%) was attributed to sulfate reduction in this system when salinity was lowest, perhaps a consequence of increased benthic light levels and photosynthetic production of labile carbon in the sediments. The sediments were a large sink for both N and P. Sediment particulate C:N (9.8) and C:P (119) ratios were lower than those in the water column. However, ammonium:phosphate fluxes increased coincident with increased sulfate reduction rates and porewater sulfide concentrations. Efficient N-retention mediated through dissimilative nitrate reduction to ammonium, and high rates of N-fixation in shallow, hypersaline systems may facilitate transitions from N-limitation to P-limitation. During the most hypersaline period, seston exhibited some of the most extreme nutrient ratios ever reported for a marine ecosystem (C:N 10-37 and C:P 200-1200) and suggest that plankton are likely to be P-limited or are very well adapted to low P availability. When salinity and N:P and C:P ratios were highest, the plankton was dominated by a brown tide alga ( Aureoumbra lagunensis), supporting evidence that this organism is adapted to low P, long residence time systems.

  2. Fungal communities of young and mature hypersaline microbial mats.

    PubMed

    Cantrell, Sharon A; Tkavc, Rok; Gunde-Cimerman, Nina; Zalar, Polona; Acevedo, Manuel; Báez-Félix, Claribel

    2013-01-01

    Microbial mats are a laminated organic-sedimentary ecosystem, found in a wide range of habitats. Fluctuating diel and seasonal physicochemical gradients characterize these ecosystems, resulting in both strata and microenvironments that harbor specific microbial communities. This study was undertaken to compare two types of microbial mats across seasons to further understand the structure of fungal communities in hypersaline microbial mats and their seasonal dynamics. The structure and diversity of fungal communities was documented in young transient and mature hypersaline microbial mats from a tropical region (Puerto Rico) using one culture-dependent and three culture-independent molecular techniques based on the internal transcribed spacer (ITS) region of ribosomal DNA: terminal restriction fragment length polymorphism (TRFLP), denaturing gradient gel electrophoresis (DGGE) and clone libraries. Two microbial mats (one young and transient, one mature) were sampled in Nov 2007 (wet season), Jan 2008 (intermediate season) and Mar 2008 (dry season) in the Cabo Rojo Solar Salterns on the southwestern coast of Puerto Rico. Traditional and molecular techniques revealed strong spatial and temporal heterogeneities in both microbial mats. Higher abundance of isolates and phylotypes were observed during the wet season, and diversity decreased from the top (oxic) to the bottom (anoxic) layers in both seasons. Some of the species isolated belong to the genera Aspergillus, Cladosporium, Hortaea, Pichia and Wallemia, which often are isolated from hypersaline environments. The most abundant clones belong to Acremonium strictum and Cladosporium halotolerans, which were not isolated in pure culture. The differences observed using culture-based and molecular techniques demonstrates the need of combining methods to study the diversity of fungi in a given substrate.

  3. Climate change in Brazil: perspective on the biogeochemistry of inland waters.

    PubMed

    Roland, F; Huszar, V L M; Farjalla, Vf; Enrich-Prast, A; Amado, A M; Ometto, J P H B

    2012-08-01

    Although only a small amount of the Earth's water exists as continental surface water bodies, this compartment plays an important role in the biogeochemical cycles connecting the land to the atmosphere. The territory of Brazil encompasses a dense river net and enormous number of shallow lakes. Human actions have been heavily influenced by the inland waters across the country. Both biodiversity and processes in the water are strongly driven by seasonal fluvial forces and/or precipitation. These macro drivers are sensitive to climate changes. In addition to their crucial importance to humans, inland waters are extremely rich ecosystems, harboring high biodiversity, promoting landscape equilibrium (connecting ecosystems, maintaining animal and plant flows in the landscape, and transferring mass, nutrients and inocula), and controlling regional climates through hydrological-cycle feedback. In this contribution, we describe the aquatic ecological responses to climate change in a conceptual perspective, and we then analyze the possible climate-change scenarios in different regions in Brazil. We also indentify some potential biogeochemical signals in running waters, natural lakes and man-made impoundments. The possible future changes in climate and aquatic ecosystems in Brazil are highly uncertain. Inland waters are pressured by local environmental changes because of land uses, landscape fragmentation, damming and diversion of water bodies, urbanization, wastewater load, and level of pollutants can alter biogeochemical patterns in inland waters over a shorter term than can climate changes. In fact, many intense environmental changes may enhance the effects of changes in climate. Therefore, the maintenance of key elements within the landscape and avoiding extreme perturbation in the systems are urgent to maintain the sustainability of Brazilian inland waters, in order to prevent more catastrophic future events.

  4. Algal fossils from a late precambrian, hypersaline lagoon.

    PubMed

    Oehler, D Z; Oehler, J H; Stewart, A J

    1979-07-27

    Organically preserved algal microfossils from the Ringwood evaporite deposit in the Gillen Member of the Bitter Springs Formation (late Precambrian of central Australia) are of small size, low diversity, and probable prokaryotic affinities. These rather primitive characteristics appear to reflect the stressful conditions that prevailed in a periodically stagnant, hypersaline lagoon. This assemblage (especially in comparison with the much more diverse assemblages preserved in the Loves Creek Member of the same formation) illustrates the potential utility of Proterozoic microbiotas for basin analysis and local stratigraphic correlation and demonstrates the need to base evolutionary considerations and Precambrian intercontinental biostratigraphy on biotas that inhabited less restricted environments.

  5. Spatially-resolved carbon flow through a hypersaline phototrophic microbial mat

    NASA Astrophysics Data System (ADS)

    Moran, J.; Lindemann, S. R.; Cory, A. B.; Courtney, S.; Cole, J. K.; Fredrickson, J.

    2013-12-01

    Hot Lake is a hypersaline, meromictic lake located in an endorheic basin in north-central Washington. Low annual rainfall and high evaporation rates contribute to the lake's high salinity. The predominant dissolved salt is magnesium sulfate, of which monimolimnion waters may seasonally exceed 2 M concentrations. Induced by its high salinity and meromictic nature, Hot Lake displays an inverse thermal gradient with deep horizons seasonally exceeding 50 °C. Despite extreme conditions, dense benthic microbial mats composed of cyanobacteria, anoxygenic photoheterotrophs, and bacterial heterotroph populations develop in the lake. These mats can exceed 1 cm in thickness and display vertical stratification in color due to bacterial pigmentation. Typical mat stratification includes an orange surface layer underlain by green and purple layers at increasing depth. Carbonates, including aragonite and magnesite, are observed within the mat and their formation is likely induced or influenced by microbial metabolic activities and associated pH excursions. We are exploring the role Hot Lake's microbial mats play in carbon cycling. Cyanobacteria are the dominant CO2-fixing organisms in the mat and we seek to understand the spatial and metabolic controls on how the carbon initially fixed by mat cyanobacteria is transferred to associated heterotrophic populations spread throughout the mat strata. Secondly, we seek to understand the overall net carbon balance of the mat through a growing season. We are using a stable isotope probing approach for assessing carbon uptake and migration through representative mat samples. We performed a series of ex situ incubations of freshly harvested mat samples in lake water amended with 13C-labeled bicarbonate or substrates commonly consumed by heterotrophs (including acetate and glucose) and using multiple stable isotope techniques to track label uptake, residence time, remineralization, and location within the mat. In addition to bulk isotope

  6. Continuous CO2 escape from the hypersaline Dead Sea caused by aragonite precipitation

    NASA Astrophysics Data System (ADS)

    Golan, Rotem; Lazar, Boaz; Wurgaft, Eyal; Lensky, Nadav; Ganor, Jiwchar; Gavrieli, Ittai

    2017-06-01

    Chemical precipitation of CaCO3 occurs in diverse marine and lacustrine environments. In the hypersaline Ca-chloride lakes that have been occupying the Dead Sea basin since the late Pleistocene, CaCO3 precipitated, mostly as aragonite. The aragonite sediments precipitated mainly during periods of high lake level stands as a result of mixing of bicarbonate-rich freshwater runoff with Dead Sea brine, that is Ca-rich and have high Mg/Ca ratio. During periods of arid conditions with limited freshwater inflow, water level declined, salinity increased and gypsum and halite became the dominant evaporitic minerals to precipitate. The present study investigates the carbon cycle of the Dead Sea under the current limited water and bicarbonate supply to the brine, representing periods of extremely arid conditions. The decrease of inflows to the Dead Sea in recent years stems mainly from diversion of freshwater from the drainage basin and results in dramatic water level decline and massive halite precipitation. During 2013-2014, bi-monthly depth profiles of total alkalinity, dissolved inorganic carbon (DIC) and its isotopic composition (δ13C) were conducted in the Dead Sea, from surface down to the bottom of the lake (290 m). Mass balance calculations conducted for the period 1993-2013 show that while inventories of conservative ions such as Mg2+ remained constant, the net DIC inventory of the lake decreased by ∼10%. DIC supply to the lake during this period, however, amounted to ∼10% of lake's inventory indicating that during 20 years, the lake lost ∼20% of its 1993s inventory. Compilation of historical data with our data shows that during the past two decades the lake's low DIC (∼1 mmol kg-1) and very high PCO2 (1800 ppm V) remained relatively constant, suggesting that a quasi-steady-state situation prevails. In spite of the surprisingly stable DIC and CO2 concentrations, during this 20 year period δ13CDIC increased significantly, from 1.4‰ to 2.7‰. An isotopic

  7. A numerical simulation of an observed lake breeze over Southern Lake Ontario

    NASA Astrophysics Data System (ADS)

    Maddukuri, C. Subbarao

    1982-07-01

    A time-dependent, two-dimensional primitive-equation atmospheric boundary-layer model has been applied to the South shore of Lake Ontario, using data obtained by Estoque et al. (1976). The model has correctly predicted the times of onset, maximum intensity and disappearance of the lake breeze. However, it underestimated the maximum inland penetration of the lake breeze, probably due to the fact that horizontal variations of surface potential temperature over the land had not been taken into account.

  8. Holocene Depositional History of Shad Pond, a Hypersaline Coastal Lagoon, Eleuthera, Bahamas and Its Influence on Lucayan Occupation

    NASA Astrophysics Data System (ADS)

    Boush, L. E.; Fentress, S.; Conroy, M.; Cook, A.; Miseridina, D.; Buynevich, I. V.; Myrbo, A.; Brown, E. T.; Berman, M.; Gnivecki, P.; Kjellmark, E.; Savarese, M.; Brady, K.

    2013-12-01

    Shad Pond, an enclosed hypersaline lagoon on the southeastern tip of Eleuthera, Bahamas reveals a ~5000-year record of hurricane activity, as well as sea-level and climate change history. Three sediment cores recovered 1.04-2.54 m of sediment over bedrock along a transect perpendicular to shoreline. Sediment composition and grain size, loss on ignition, X-ray fluorescence (XRF) measurements of the cores along with dune transects and ground-penetrating radar (GPR) profiles adjacent to the lake provide a comprehensive dataset to interpret the history of this coastal basin. The sedimentary sequence was composed of alternating lithofacies that included microbial mats, sand, and peat. Laminated mats often alternated with sandy layers in thin to medium-bedded units. Two peat layers were found in the basal part of the shore-distal core (Site 1) between 1.82-2.40 m and 2.53-2.54 m and were separated by a 13-cm-thick gray mud layer. In general, organic matter and carbonate content tracked granulometry and composition in all cores. High-resolution XRF scans of Ca and Sr at Site 1 show elevated levels ~3,700 cal yBP, which correlate with the top of the peat layer, but these elemental concentrations vary at Site 3. XRF measurements of Fe indicate a dust flux that has been recorded regionally throughout the Caribbean. Dune transects and GPR profiles indicate a phased history of the pond, beginning with initial stages as an open lagoon dominated by red mangrove, with black mangrove and buttonwood also present. The lake likely closed at approximately 3,700 cal yBP indicated by the transition between the upper peat and microbial mat layers. This could have been due to increased storm events in a regime of rising sea level. Aeolian aggradation continued to heighten the barrier between the bedrock headlands to its present position. Hurricane overwash deposits punctuated the algal mat accumulation throughout this time period. Present-day hypersaline conditions sustain algal mats

  9. Anaerobic oxidation of methane in hypersaline cold seep sediments.

    PubMed

    Maignien, Loïs; Parkes, R John; Cragg, Barry; Niemann, Helge; Knittel, Katrin; Coulon, Stephanie; Akhmetzhanov, Andrey; Boon, Nico

    2013-01-01

    Life in hypersaline environments is typically limited by bioenergetic constraints. Microbial activity at the thermodynamic edge, such as the anaerobic oxidation of methane (AOM) coupled to sulphate reduction (SR), is thus unlikely to thrive in these environments. In this study, carbon and sulphur cycling was investigated in the extremely hypersaline cold seep sediments of Mercator mud volcano. AOM activity was partially inhibited but still present at salinity levels of 292 g L(-1) (c. eightfold sea water concentration) with rates of 2.3 nmol cm(-3) day(-1) and was even detectable under saturated conditions. Methane and evaporite-derived sulphate comigrated in the ascending geofluids, which, in combination with a partial activity inhibition, resulted in AOM activity being spread over unusually wide depth intervals. Up to 79% of total cells in the AOM zone were identified by fluorescence in situ hybridization (FISH) as anaerobic methanotrophs of the ANME-1. Most ANME-1 cells formed monospecific chains without any attached partner. At all sites, AOM activity co-occurred with SR activity and sometimes significantly exceeded it. Possible causes of these unexpected results are discussed. This study demonstrates that in spite of a very low energy yield of AOM, microorganisms carrying this reaction can thrive in salinity up to halite saturation.

  10. Lipid Biomarkers for a Hypersaline Microbial Mat Community

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda L.; Embaye, Tsege; Turk, Kendra A.

    2003-01-01

    The use of lipid biomarkers and their carbon isotopic compositions are valuable tools for establishing links to ancient microbial ecosystems. As witnessed by the stromatolite record, benthic microbial mats grew in shallow water lagoonal environments where microorganisms had virtually no competition apart from the harsh conditions of hypersalinity, desiccation and intense light. Today, the modern counterparts of these microbial ecosystems find appropriate niches in only a few places where extremes eliminate eukaryotic grazers. Answers to many outstanding questions about the evolution of microorganisms and their environments on early Earth are best answered through study of these extant analogs. Lipids associated with various groups of bacteria can be valuable biomarkers for identification of specific groups of microorganisms both in ancient organic-rich sedimentary rocks (geolipids) and contemporary microbial communities (membrane lipids). Use of compound specific isotope analysis adds additional refinement to the identification of biomarker source, so that it is possible to take advantage of the 3C-depletions associated with various functional groups of organisms (i.e. autotrophs, heterotrophs, methanotrophs, methanogens) responsible for the cycling of carbon within a microbial community. Our recent work has focused on a set of hypersaline evaporation ponds at Guerrero Negro, Baja California Sur, Mexico which support the abundant growth of Microcoleus-dominated microbial mats. Specific biomarkers for diatoms, cyanobacteria, archaea, green nonsulfur (GNS), sulfate reducing, and methanotrophic bacteria have been identified. Analyses of the ester-bound fatty acids indicate a highly diverse microbial community, dominated by photosynthetic organisms at the surface.

  11. Lipid Biomarkers for a Hypersaline Microbial Mat Community

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda L.; Embaye, Tsege; Turk, Kendra A.

    2003-01-01

    The use of lipid biomarkers and their carbon isotopic compositions are valuable tools for establishing links to ancient microbial ecosystems. As witnessed by the stromatolite record, benthic microbial mats grew in shallow water lagoonal environments where microorganisms had virtually no competition apart from the harsh conditions of hypersalinity, desiccation and intense light. Today, the modern counterparts of these microbial ecosystems find appropriate niches in only a few places where extremes eliminate eukaryotic grazers. Answers to many outstanding questions about the evolution of microorganisms and their environments on early Earth are best answered through study of these extant analogs. Lipids associated with various groups of bacteria can be valuable biomarkers for identification of specific groups of microorganisms both in ancient organic-rich sedimentary rocks (geolipids) and contemporary microbial communities (membrane lipids). Use of compound specific isotope analysis adds additional refinement to the identification of biomarker source, so that it is possible to take advantage of the 3C-depletions associated with various functional groups of organisms (i.e. autotrophs, heterotrophs, methanotrophs, methanogens) responsible for the cycling of carbon within a microbial community. Our recent work has focused on a set of hypersaline evaporation ponds at Guerrero Negro, Baja California Sur, Mexico which support the abundant growth of Microcoleus-dominated microbial mats. Specific biomarkers for diatoms, cyanobacteria, archaea, green nonsulfur (GNS), sulfate reducing, and methanotrophic bacteria have been identified. Analyses of the ester-bound fatty acids indicate a highly diverse microbial community, dominated by photosynthetic organisms at the surface.

  12. Differences in lateral gene transfer in hypersaline versus thermal environments.

    PubMed

    Rhodes, Matthew E; Spear, John R; Oren, Aharon; House, Christopher H

    2011-07-08

    The role of lateral gene transfer (LGT) in the evolution of microorganisms is only beginning to be understood. While most LGT events occur between closely related individuals, inter-phylum and inter-domain LGT events are not uncommon. These distant transfer events offer potentially greater fitness advantages and it is for this reason that these "long distance" LGT events may have significantly impacted the evolution of microbes. One mechanism driving distant LGT events is microbial transformation. Theoretically, transformative events can occur between any two species provided that the DNA of one enters the habitat of the other. Two categories of microorganisms that are well-known for LGT are the thermophiles and halophiles. We identified potential inter-class LGT events into both a thermophilic class of Archaea (Thermoprotei) and a halophilic class of Archaea (Halobacteria). We then categorized these LGT genes as originating in thermophiles and halophiles respectively. While more than 68% of transfer events into Thermoprotei taxa originated in other thermophiles, less than 11% of transfer events into Halobacteria taxa originated in other halophiles. Our results suggest that there is a fundamental difference between LGT in thermophiles and halophiles. We theorize that the difference lies in the different natures of the environments. While DNA degrades rapidly in thermal environments due to temperature-driven denaturization, hypersaline environments are adept at preserving DNA. Furthermore, most hypersaline environments, as topographical minima, are natural collectors of cellular debris. Thus halophiles would in theory be exposed to a greater diversity and quantity of extracellular DNA than thermophiles.

  13. Methanogenesis in hypersaline environments -Analogs for Ancient Mars?

    NASA Astrophysics Data System (ADS)

    Bebout, Brad; Chanton, Jeff; Kelley, Cheryl; Tazaz, Amanda; Poole, Jennifer; García Maldonado, José Q.; López Cortés, Alejandro

    The recent findings of evidence of large bodies of hypersaline water which existed in the past on Mars have underscored the need to investigate those environments for evidence of past, as well as extant, life. Methane, a key biomarker gas, has been reported in the atmosphere of Mars, and is known to be produced by microbial mats which are present in most hypersaline environments on Earth. Modern microbial mat communities are thought to be extant analogues of communities which were present early in Earth's geologic history, when environmental condition on Earth and Mars were similar. Because methane may be an indication of life (biogenic methane) but might also be a consequence of geologic activity (abiotic methane) and/or the thermal alteration of ancient organic matter (thermogenic methane), the stable isotopic composition of methane (both carbon and hydrogen) will be a key criterion for determining whether or not the methane on Mars is biologically produced, and if so, how recently (i.e., biogenic vs. thermogenic methane). The goals of our study are: a) to document the range of the stable isotopic composition of methane (both carbon and hydrogen) in hypersaline environments, and b) to understand the role of biology in generating that stable isotopic composition. Our results will help provide a framework for the interpretation of methane stable isotopic data from Mars. We have measured high concentrations of methane in bubbles of gas present in the Guerrero Negro hypersaline ecosystem, Baja California Mexico and in salt ponds on the San Francisco Bay. These bubbles are present both in sediments underlying microbial mats (including one site where methane constitutes nearly 40% by volume of the bubbles), as well as in areas not colonized by microbial mats; layers of evaporitic minerals in some areas trap gas containing high concentrations of methane. The carbon isotopic (δ 13 C) composition of the methane in collected bubbles exhibited an extremely wide range of

  14. Impacts of hypersaline acclimation on the acute toxicity of the organophosphate chlorpyrifos to salmonids.

    PubMed

    Maryoung, Lindley A; Lavado, Ramon; Schlenk, Daniel

    2014-07-01

    Acclimation to hypersaline conditions enhances the acute toxicity of certain thioether organophosphate and carbamate pesticides in some species of euryhaline fish. As the organophosphate chlorpyrifos is commonly detected in salmonid waterways, the impacts of hypersaline conditions on its toxicity were examined. In contrast to other previously examined pesticides, time to death by chlorpyrifos was more rapid in freshwater than in hypersaline water (16ppth). The median lethal time (LT50) after 100μg/L chlorpyrifos exposure was 49h (95% CI: 31-78) and 120h (95% CI: 89-162) for rainbow trout (Oncorhynchus mykiss) in freshwater and those acclimated to hypersaline conditions, respectively. Previous studies with hypersaline acclimated fish indicated induction of xenobiotic metabolizing enzymes that may detoxify chlorpyrifos. In the current study, chlorpyrifos metabolism was unaltered in liver and gill microsomes of freshwater and hypersaline acclimated fish. Acetylcholinesterase inhibition in brain and bioavailability of chlorpyrifos from the aqueous exposure media were also unchanged. In contrast, mRNA expression of neurological targets: calcium calmodulin dependent protein kinase II delta, chloride intracellular channel 4, and G protein alpha i1 were upregulated in saltwater acclimated fish, consistent with diminished neuronal signaling which may protect animals from cholinergic overload associated with acetylcholinesterase inhibition. These results indicate targets other than acetylcholinesterase may contribute to the altered toxicity of chlorpyrifos in salmonids under hypersaline conditions.

  15. Rehabilitating China's largest inland river.

    PubMed

    Li, Yiqing; Chen, Yaning; Zhang, Yaoqi; Xia, Yang

    2009-06-01

    Wetlands are particularly important for conserving China's biodiversity but riparian wetlands in the Tarim River basin in western China have been reduced by 46% during the last 3 decades. The world's largest habitat for Populus euphratica, which is in the Tarim River basin, significantly shrank. To protect and restore the deteriorated ecosystems along the Tarim River and its associated wetlands, China's government initiated a multimillion dollar river restoration project to release water from upper dams to the dried-up lower reaches of the Tarim River starting in 2000. We monitored the responses of groundwater and vegetation to water recharge in the lower reaches of the river from 2000 to 2006 by establishing nine 1000-m-long transects perpendicular to the river at intervals of 20-45 km along the 320-km river course below the Daxihaizi Reservoir, the source of water conveyance, to Lake Taitema, the terminus of the Tarim River. Water recharges from the Daxihaizi Reservoir to the lower reaches of the Tarim River significantly increased groundwater levels and vegetation coverage at all monitoring sites along the river. The mean canopy size of the endangered plant species P. euphratica doubled after 6 years of water recharge. Some rare migrating birds returned to rest on the restored wetlands in summer along the lower reaches of the Tarim River. The biggest challenge facing decision makers, however, is to balance water allocation and water rights between agricultural and natural ecosystems in a sustainable way. A large number of inhabitants in the Tarim Basin depend on these limited water resources for a living. At the same time, the endangered ecosystems need to be protected. Given the ecological, socioeconomic, and sociopolitical realities in the Tarim Basin, adaptive water policies and strategies are needed for water allocation in these areas of limited water resources.

  16. 77 FR 26522 - Inland Waterways Users Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-04

    .... Name of Committee: Inland Waterways Users Board (Board). Date: June 6, 2012. Location: The OMNI William Penn Hotel, 530 William Penn Place, Pittsburgh, PA 15219 at 412-281-7100 or 1-800-843-6664 or www.omnihotels.com/FindAHotel/PittsburghWilliamPenn.aspx . Time: Registration will begin at 8:30 a.m. and...

  17. 77 FR 27007 - Inland Waterways Navigation Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-08

    ... SECURITY Coast Guard 33 CFR Part 162 RIN 1625-AB84 Inland Waterways Navigation Regulations AGENCY: Coast... waterways navigation regulations. Specifically, this rule proposes to redefine the geographical points which... navigation restrictions on the public and private industry. If you think that your business, organization,...

  18. 75 FR 57264 - Inland Waterways Users Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF DEFENSE Department of the Army; Corps of Engineers Inland Waterways Users Board AGENCY: Department of the Army, U.S... Casino Hotel Bettendorf, 1777 Isle Parkway, Bettendorf, Iowa 52722 at 1-800-843-4753 or 1-800-724-5825...

  19. Forest ecosystem health in the inland west

    Treesearch

    R. Neil Sampson; Lance R. Clark; Lynnette Z. Morelan

    1995-01-01

    For the past four years, American Forests has focused much of its policy attention on forest health, highlighted by a forest health partnership in southern Idaho. The partnership has been hard at work trying to better understand the forests of the Inland West. Our goal has been to identify what is affecting these forests, why they are responding differently to climate...

  20. 77 FR 28825 - Inland Waterways Navigation Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-16

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 162 RIN 1625-AB84 Inland Waterways Navigation Regulations AGENCY: Coast Guard, DHS. ACTION: Notice of proposed rulemaking; Correction of Preamble. SUMMARY: This document makes...

  1. 75 FR 41987 - Inland Navigation Rules; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-20

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AB43 Inland Navigation Rules; Correction ACTION: Final rule... Navigation Rules into the Code of Federal Regulations. That publication contained an error in the...

  2. 33 CFR 162.120 - Harbors on Lake Michigan.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Harbors on Lake Michigan. 162.120 Section 162.120 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.120 Harbors on Lake...

  3. 33 CFR 162.120 - Harbors on Lake Michigan.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Harbors on Lake Michigan. 162.120 Section 162.120 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.120 Harbors on Lake...

  4. Comprehensive lake dynamics mapping at continental scales using Landsat 8

    USDA-ARS?s Scientific Manuscript database

    Inland lakes, important water resources, play a crucial role in the global water cycle and are sensitive to global warming and human activities. There clearly is a pressing need to understand temporal and spatial variations of lakes at global and continental scales. The recent operation of Landsat...

  5. 78 FR 23849 - Inland Waterways Navigation Regulation: Sacramento River, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-23

    ... SECURITY Coast Guard 33 CFR Part 162 RIN 1625-AB95 Inland Waterways Navigation Regulation: Sacramento River... entitled, ``Inland Waterways Navigation Regulation: Sacramento River, CA'' in the Federal Register (78 FR 4785). That rule announced our intent to update the inland waterways navigation regulations by...

  6. Improved inland water levels from SAR altimetry using novel empirical and physical retrackers

    NASA Astrophysics Data System (ADS)

    Villadsen, Heidi; Deng, Xiaoli; Andersen, Ole B.; Stenseng, Lars; Nielsen, Karina; Knudsen, Per

    2016-06-01

    Satellite altimetry has proven a valuable resource of information on river and lake levels where in situ data are sparse or non-existent. In this study several new methods for obtaining stable inland water levels from CryoSat-2 Synthetic Aperture Radar (SAR) altimetry are presented and evaluated. In addition, the possible benefits from combining physical and empirical retrackers are investigated. The retracking methods evaluated in this paper include the physical SAR Altimetry MOde Studies and Applications (SAMOSA3) model, a traditional subwaveform threshold retracker, the proposed Multiple Waveform Persistent Peak (MWaPP) retracker, and a method combining the physical and empirical retrackers. Using a physical SAR waveform retracker over inland water has not been attempted before but shows great promise in this study. The evaluation is performed for two medium-sized lakes (Lake Vänern in Sweden and Lake Okeechobee in Florida), and in the Amazon River in Brazil. Comparing with in situ data shows that using the SAMOSA3 retracker generally provides the lowest root-mean-squared-errors (RMSE), closely followed by the MWaPP retracker. For the empirical retrackers, the RMSE values obtained when comparing with in situ data in Lake Vänern and Lake Okeechobee are in the order of 2-5 cm for well-behaved waveforms. Combining the physical and empirical retrackers did not offer significantly improved mean track standard deviations or RMSEs. Based on these studies, it is suggested that future SAR derived water levels are obtained using the SAMOSA3 retracker whenever information about other physical properties apart from range is desired. Otherwise we suggest using the empirical MWaPP retracker described in this paper, which is both easy to implement, computationally efficient, and gives a height estimate for even the most contaminated waveforms.

  7. Forest-Product Imports and Exports Via the Great Lakes-St. Lawrence Seaway Through Upper Lakes Ports

    Treesearch

    Eugene M. Carpenter

    1966-01-01

    The expanded Great Lakes-St. Lawrence Seaway system was opened in the early spring of 1959, and for the first time deep-draft ocean-going vessels could visit inland Great Lakes ports. In 1963 the Station published a Research Note reporting what effect this expansion may have had on the volume of forest products moving through Minnesota, Wisconsin, and Michigan ports;...

  8. Anammox bacterial populations in deep marine hypersaline gradient systems.

    PubMed

    Borin, Sara; Mapelli, Francesca; Rolli, Eleonora; Song, Bongkeun; Tobias, Craig; Schmid, Markus C; De Lange, Gert J; Reichart, Gert J; Schouten, Stefan; Jetten, Mike; Daffonchio, Daniele

    2013-03-01

    To extend the knowledge of anaerobic ammonium oxidation (anammox) habitats, bacterial communities were examined in two hypersaline sulphidic basins in Eastern Mediterranean Sea. The 2 m thick seawater-brine haloclines of the deep anoxic hypersaline basins Bannock and L'Atalante were sampled in intervals of 10 cm with increasing salinity. (15)N isotope pairing incubation experiments showed the production of (29)N2 and (30)N2 gases in the chemoclines, ranging from 6.0 to 9.2 % salinity of the L'Atalante basin. Potential anammox rates ranged from 2.52 to 49.65 nmol N2 L(-1) day(-1) while denitrification was a major N2 production pathway, accounting for more than 85.5 % of total N2 production. Anammox-related 16S rRNA genes were detected along the L'Atalante and Bannock haloclines up to 24 % salinity, and the amplification of the hydrazine synthase genes (hzsA) further confirmed the presence of anammox bacteria in Bannock. Fluorescence in situ hybridisation and sequence analysis of 16S rRNA genes identified representatives of the marine anammox genus 'Candidatus Scalindua' and putatively new operational taxonomic units closely affiliated to sequences retrieved in marine environments that have documented anammox activity. 'Scalindua brodae' like sequences constituted up to 84.4 % of the sequences retrieved from Bannock. The anammox community in L'Atalante was different than in Bannock and was stratified according to salinity increase. This study putatively extends anammox bacterial habitats to extremely saline sulphidic ecosystems.

  9. Differences in lateral gene transfer in hypersaline versus thermal environments

    PubMed Central

    2011-01-01

    Background The role of lateral gene transfer (LGT) in the evolution of microorganisms is only beginning to be understood. While most LGT events occur between closely related individuals, inter-phylum and inter-domain LGT events are not uncommon. These distant transfer events offer potentially greater fitness advantages and it is for this reason that these "long distance" LGT events may have significantly impacted the evolution of microbes. One mechanism driving distant LGT events is microbial transformation. Theoretically, transformative events can occur between any two species provided that the DNA of one enters the habitat of the other. Two categories of microorganisms that are well-known for LGT are the thermophiles and halophiles. Results We identified potential inter-class LGT events into both a thermophilic class of Archaea (Thermoprotei) and a halophilic class of Archaea (Halobacteria). We then categorized these LGT genes as originating in thermophiles and halophiles respectively. While more than 68% of transfer events into Thermoprotei taxa originated in other thermophiles, less than 11% of transfer events into Halobacteria taxa originated in other halophiles. Conclusions Our results suggest that there is a fundamental difference between LGT in thermophiles and halophiles. We theorize that the difference lies in the different natures of the environments. While DNA degrades rapidly in thermal environments due to temperature-driven denaturization, hypersaline environments are adept at preserving DNA. Furthermore, most hypersaline environments, as topographical minima, are natural collectors of cellular debris. Thus halophiles would in theory be exposed to a greater diversity and quantity of extracellular DNA than thermophiles. PMID:21740576

  10. Monitoring Inland Ice Cover under All-weather Conditions with the Combined Use of Microwave and GOES-R Observations

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Key, J. R.; Wang, X.

    2010-12-01

    The cryosphere exists at all latitudes and in about one hundred countries. Not only does the cryosphere play a significant role in climate, but also it has profound socio-economic value, especially over inland water, including lakes and rivers, due to its role in water resources and its impact on transportation, fisheries, hunting, herding, and agriculture. A number of ice characterization algorithms have been improved and/or developed for the next generation Geostationary Operational Environmental Satellite (GOES-R) Advanced Baseline Imager (ABI), including ice identification, ice concentration, ice thickness and age, and ice motion. These products will play an important role in monitoring ice cover over inland water considering its high spatial, temporal, and spectral resolution. However, the effectiveness of such products is constrained by cloud cover. Lake ice products from microwave observations are less affected by clouds, but their quality is hindered by coarse spatial and temporal resolution as well as contamination by the land surface. Optimization of all-weather ice products from microwave observations, and ice products with higher spatial and temporal resolutions from GOES-R enables us to monitor the ice characteristics over the inland water surfaces, e.g., the Great Lakes, effectively in real time under all-weather conditions, and improves the products that are being developed for ABI. The combined used of both products provides accurate, timely information on ice characteristics over inland water surfaces to meet the needs of transportation and winter weather forecasting. An overview of the ice cover, concentration, and motion products for both GOES-R and microwave observation will be given, and case studies of combining both products for monitoring ice characteristics over inland water will be presented.

  11. Michigan lakes: An assessment of water quality

    USGS Publications Warehouse

    Minnerick, R.J.

    2004-01-01

    Michigan has more than 11,000 inland lakes, that provide countless recreational opportunities and are an important resource that makes tourism and recreation a $15-billion-dollar per-year industry in the State (Stynes, 2002). Knowledge of the water-quality characteristics of inland lakes is essential for the current and future management of these resources.Historically the U. S. Geological Survey (USGS) and the Michigan Department of Environmental Quality (MDEQ) jointly have monitored water quality in Michigan's lakes and rivers. During the 1990's, however, funding for surface-water-quality monitoring was reduced greatly. In 1998, the citizens of Michigan passed the Clean Michigan Initiative to clean up, protect, and enhance Michigan's environmental infrastructure. Because of expanding water-quality-data needs, the MDEQ and the USGS jointly redesigned and implemented the Lake Water-Quality Assessment (LWQA) Monitoring Program (Michigan Department of Environmental Quality, 1997).

  12. MILLIMETER-SCALE GENETIC GRADIENTS AND COMMUNITY-LEVEL MOLECULAR CONVERGENCE IN A HYPERSALINE MICROBIAL MAT

    SciTech Connect

    Fenner, Marsha W; Kunin, Victor; Raes, Jeroen; Harris, J. Kirk; Spear, John R.; Walker, Jeffrey J.; Ivanova, Natalia; Mering, Christian von; Bebout, Brad M.; Pace, Norman R.; Bork, Peer; Hugenholtz, Philip

    2008-04-30

    To investigate the extent of genetic stratification in structured microbial communities, we compared the metagenomes of 10 successive layers of a phylogenetically complex hypersaline mat from Guerrero Negro, Mexico. We found pronounced millimeter-scale genetic gradients that are consistent with the physicochemical profile of the mat. Despite these gradients, all layers displayed near identical and acid-shifted isoelectric point profiles due to a molecular convergence of amino acid usage indicating that hypersalinity enforces an overriding selective pressure on the mat community.

  13. Inland Water Temperature: An Ideal Indicator for the National Climate Assessment

    NASA Astrophysics Data System (ADS)

    Hook, S. J.; Lenters, J. D.; O'Reilly, C.; Healey, N. C.

    2014-12-01

    NASA is a significant contributor to the U.S. National Climate Assessment (NCA), which is a central component of the 2012-2022 U.S. Global Change Research Program Strategic Plan. The NCA has identified the need for indicators that provide a clear, concise way of communicating to NCA audiences about not only the status and trends of physical drivers of the climate system, but also the ecological and socioeconomic impacts, vulnerabilities, and responses to those drivers. We are using thermal infrared satellite data in conjunction with in situ measurements to produce water temperatures for all the large inland water bodies in North America for potential use as an indicator for the NCA. Recent studies have revealed significant warming of inland waters throughout the world. The observed rate of warming is - in many cases - greater than that of the ambient air temperature. These rapid, unprecedented changes in inland water temperatures have profound implications for lake hydrodynamics, productivity, and biotic communities. Scientists are just beginning to understand the global extent, regional patterns, physical mechanisms, and ecological consequences of lake warming. As part of our earlier studies we have collected thermal infrared satellite data from those satellite sensors that provide long-term and frequent spaceborne thermal infrared measurements of inland waters including ATSR, AVHRR, and MODIS and used these to examine trends in water surface temperature for approximately 100 of the largest inland water bodies in the world. We are now extending this work to generate temperature time-series of all North American inland water bodies that are sufficiently large to be studied using 1km resolution satellite data for the last 3 decades. These data are then being related to changes in the surface air temperature and compared with regional trends in water surface temperature derived from CMIP5/IPCC model simulations/projections to better predict future temperature changes

  14. SICS: the Southern Inland and Coastal System interdisciplinary project of the USGS South Florida Ecosystem Program

    USGS Publications Warehouse

    ,

    2011-01-01

    State and Federal agencies are working jointly on structural modifications and improved water-delivery strategies to reestablish more natural surface-water flows through the Everglades wetlands and into Florida Bay. Changes in the magnitude, duration, timing, and distribution of inflows from the headwaters of the Taylor Slough and canal C-111 drainage basins have shifted the seasonal distribution and extent of wetland inundation, and also contributed to the development of hypersaline conditions in nearshore embayments of Florida Bay. Such changes are altering biological and vegetative communities in the wetlands and creating stresses on aquatic habitat. Affected biotic resources include federally listed species such as the Cape Sable seaside sparrow, American crocodile, wood stork, and roseate spoonbill. The U.S. Geological Survey (USGS) is synthesizing scientific findings from hydrologic process studies, collecting data to characterize the ecosystem properties and functions, and integrating the results of these efforts into a research tool and management model for this Southern Inland and Coastal System(SICS). Scientists from all four disciplinary divisions of the USGS, Biological Resources, Geology, National Mapping, and Water Resources are contributing to this interdisciplinary project.

  15. Diversity of culturable halophilic sulfur-oxidizing bacteria in hypersaline habitats.

    PubMed

    Sorokin, Dimitry Yu; Tourova, Tatjana P; Lysenko, Anatoly M; Muyzer, Gerard

    2006-10-01

    Unexpectedly high culturable diversity of moderately and extremely halophilic obligately chemolithoautotrophic sulfur-oxidizing bacteria (SOB) was discovered in the sediments of various hypersaline habitats, including chloride-sulfate lakes in Mongolia, Russia and Ukraine, a sea saltern in Slovenia and a deep-sea salt brine from the Mediterranean. Six different groups of halophilic SOB, including four new genera, all belonging to the Gammaproteobacteria, were found. Two groups of moderately halophilic strictly aerobic SOB dominated at 2 M NaCl, including representatives of the genus Halothiobacillus (in fully aerobic conditions) and Thiomicrospira (in micro-oxic conditions). Under denitrifying conditions at 2 M NaCl, a group of moderately halophilic and facultatively anaerobic SOB was selected, capable of complete denitrification of nitrate. The group represents a new genus with closest relatives among as yet undescribed marine thiodenitrifying isolates. With thiocyanate as a substrate, an enrichment culture at 2 M NaCl yielded a pure culture of moderately halophilic SOB capable of aerobic growth with thiocyanate and thiosulfate at up to 4 M NaCl. Furthermore, this bacterium also grew anaerobically using nitrite as electron acceptor. It formed a new lineage distantly related to the genus Thiomicrospira. Enrichments at 4 M NaCl resulted in the domination of two different, previously unknown, groups of extremely halophilic SOB. Under oxic conditions, they were represented by strictly aerobic spiral-shaped bacteria, related to the Ectothiorhodospiraceae, while under denitrifying conditions a group of facultatively anaerobic nitrate-reducing bacteria with long rod-shaped cells was selected, distantly related to the genus Acidithiobacillus.

  16. Enhanced bioremediation of oil-polluted, hypersaline, coastal areas in Kuwait via vitamin-fertilization.

    PubMed

    Al-Mailem, Dina M; Eliyas, Mohamed; Radwan, Samir

    2014-03-01

    There is no research published sofar on managements that could bioremediate hypersaline soils and water polluted with hydrocarbons. The objective of this study was to assess the effect of vitamin amendment on hydrocarbon removal by microorganisms indigenous to such hypersaline environments. We used in this study ten hydrocarbonoclastic bacterial species and five archaeal species that had been isolated by the conventional plating method on media containing oil as a sole carbon source, from a hypersaline (3-4 M NaCl) coastal area in Kuwait, and characterized by sequencing of their 16S rRNA coding genes. The oil and pure hydrocarbon consumption was measured by gas-liquid chromatography. The oil and pure hydrocarbon consumption potential of all microorganisms in media with hypersalinity was enhanced by vitamin fertilization. This was true for individual microorganisms in pure cultures as well as for microbial consortia in hypersaline soil and water samples used as inocula. Most effective vitamins were thiamin, pyridoxine and vitamin B12. Vitamin fertilization using vitamin rich wastes or byproducts could be an effective practice for enhancing bioremediation of oil contaminated hypersaline environments.

  17. "The Effect of Alternative Representations of Lake Temperatures and Ice on WRF Regional Climate Simulations"

    EPA Science Inventory

    Lakes can play a significant role in regional climate, modulating inland extremes in temperature and enhancing precipitation. Representing these effects becomes more important as regional climate modeling (RCM) efforts focus on simulating smaller scales. When using the Weathe...

  18. "The Effect of Alternative Representations of Lake Temperatures and Ice on WRF Regional Climate Simulations"

    EPA Science Inventory

    Lakes can play a significant role in regional climate, modulating inland extremes in temperature and enhancing precipitation. Representing these effects becomes more important as regional climate modeling (RCM) efforts focus on simulating smaller scales. When using the Weathe...

  19. Tracking and predicting barges on inland waterways

    SciTech Connect

    Randeniya, Duminda I; Hilliard, Michael R

    2013-01-01

    We present a non-linear, probabilistic prediction model developed and implemented to track spatial location and other navigation characteristics of a barge traveling on the inland waterway system. A pre-filter, to check the validity of the measurements, a non-linear speed estimation process, and a Kalman filter to predict the navigation solution of the barge is developed in this work. Due to the complex dynamics involved in the system, a non-linear stochastic model was developed in state space using system dynamics to represent the process and measurement systems while maintaining the fidelity of an actual system. The algorithm was verified using actual measurements obtained from multiple barges on multiple rivers acquired from different sensors. The results show a reliable and robust prediction algorithm for tracking inland waterway barges.

  20. Late quaternary sediments, minerals, and inferred geochemical history of Didwana Lake, Thar Desert, India

    USGS Publications Warehouse

    Wasson, R.J.; Smith, G.I.; Agrawal, D.P.

    1984-01-01

    Variations in clastic sediment texture, mineralogy of both evaporites formed at the surface and precipitates formed below the lake floor, and the relative chemical activities of the major dissolved components of the chemical precipitates, have allowed reconstruction of the history of salinity and water-level changes in Didwana Lake, Thar Desert, India. Hypersaline conditions prevailed at about the Last Glacial Maximum, with little evidence of clastic sediments entering the lake. Between ca. 13,000 and 6000 B.P. the lake level fluctuated widely, the lake alternately hypersaline and fresh, and clastic sediments were delivered to the lake at a low rate. Deep-water conditions occurred ca. 6000 B.P. and clastic influx increased abruptly. The water level dropped towards 4000 B.P. when the lake dried briefly. Since 4000 B.P. the lake has been ephemeral with a lowered rate of sedimentation and mildly saline conditions rather like those of today. This sequence of changes documented in the lake parallels changes in vegetation recorded in published pollen diagrams from both the Thar and the Arabian Sea. Correlation of the various lines of evidence suggests that the climate of the Last Glacial Maximum at Didwana was dry and windy with a weak monsson circulation. The monsson was re-established between ca. 13,000 and a little before 6000 B.P., and, when winter rainfall increased ca. 6000 B.P., the lake filled to its maximum depth. ?? 1984.

  1. Dynamics of absorption properties along a latitudinal gradient: sources of absorption in Australian inland waters

    NASA Astrophysics Data System (ADS)

    Hestir, E. L.; Campbell, G.; Malthus, T. J.; Dekker, A.; Botha, E.

    2013-12-01

    Australian inland waters are optically complex and vary spatially and temporally. Inversion of optical remote sensing data for the retrieval of optically active water quality constituents (chlorophyll, colored dissolved organic matter and total suspended solids) is impeded by the scarcity of inherent optical property (IOP) data sets. In 2012 a major measurement program commenced to improve understanding of IOPs in Australia. Seven large lakes were sampled along a latitudinal gradient in Eastern Australia; in situ observations were made of the absorption properties of the water quality during two epochs (wet and dry season). This study documents the seasonal, inter & intra lake variability of the absorption budget of Australian lakes. These data reveal the sources of biogeochemical constituents determining the light climate of lakes. Optically active water quality constituents (total suspended solids, chlorophyll-a, and colored dissolved organic matter) varied significantly between wet and dry season and between lakes. The primary contribution to the absorption budget was from non-algal particulate matter (NAP; 10-60%), followed by colored dissolved organic matter (CDOM; 20-80%). Absorption from phytoplankton contributed only 0-30% of the total budget. This indicates that these lakes are primarily light limited, though the limitation comes from multiple sources. The contribution of NAP to the total absorption budget showed the greatest amount of variance between wet and dry seasons. Examination of the organic matter and estimated phytoplankton biomass contributions to TSS reveal that chlorophyll is not the primary source of organic matter in Australian lakes: allochthonous inputs are the primary trophic driver. Finally, there is strong regional and seasonal variation in the IOPs of the lakes, with the exception of the slope of CDOM. The slope of CDOM was not significantly different between seasons (p=0.94). Non-parametric stepwise multiple comparisons showed the

  2. Lipid Biomarkers for a Hypersaline Microbial Mat Community

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda; Orphan, Victoria; Embaye, Tsegereda; Turk, Kendra; Kubo, Mike; Summons, Roger

    2004-01-01

    The use of lipid biomarkers and their carbon isotopic compositions are valuable tools for establishing links to ancient microbial ecosystems. Various lipids associated with specific microbial groups can serve as biomarkers for establishing organism source and function in contemporary microbial ecosystems (membrane lipids), and by analogy, potential relevance to ancient organic-rich sedimentary rocks (geolipids). As witnessed by the stromatolite record, benthic microbial mats grew in shallow water lagoonal environments. Our recent work has focused on lipid biomarker analysis of a potential analogue for such ancient mats growing in a set of hypersaline evaporation ponds at Guerrero Negro, Baja California Sur, Mexico. The aerobic, surface layer of this mat (0 to 1 mm) contained a variety of ester-bound fatty acids (FA) representing a diverse bacterial population including cyanobacteria, sulphate reducers (SRB) and heterotrophs. Biomarkers for microeukaryotes detected in this layer included sterols, C-20 polyunsaturated FA and a highly branched isoprenoid, diagnostic for diatoms. Cyanobacteria were also indicated by the presence of a diagnostic set of mid-chain methylalkanes. C-28, to C-34 wax esters (WXE) present in relatively small amounts in the upper 3 mm of the mat are considered biomarkers for green non-sulphur bacteria. Ether-bound isoprenoids were also identified although in considerably lower abundance than ester-bound FA (approx. 1:l0). These complex ether lipids included archatol, hydroxyarchaeol and a C-40 tetraether, all in small amounts. After ether cleavage with boron tribromide, the major recovered isoprenyl was a C-30:1. This C(sub 30;1) yelded squalane after hydrogenation, a known geobiomarker for hypersaline environments in ancient oils and sediments. In this mat, it represents the dominant Archaeal population. The carbon isotopic composition of biomarker lipids were generally depleted relative to the bulk organic material (delta C-13 TOC -10%). Most

  3. Lipid Biomarkers for a Hypersaline Microbial Mat Community

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda; Orphan, Victoria; Embaye, Tsegereda; Turk, Kendra; Kubo, Mike; Summons, Roger

    2004-01-01

    The use of lipid biomarkers and their carbon isotopic compositions are valuable tools for establishing links to ancient microbial ecosystems. Various lipids associated with specific microbial groups can serve as biomarkers for establishing organism source and function in contemporary microbial ecosystems (membrane lipids), and by analogy, potential relevance to ancient organic-rich sedimentary rocks (geolipids). As witnessed by the stromatolite record, benthic microbial mats grew in shallow water lagoonal environments. Our recent work has focused on lipid biomarker analysis of a potential analogue for such ancient mats growing in a set of hypersaline evaporation ponds at Guerrero Negro, Baja California Sur, Mexico. The aerobic, surface layer of this mat (0 to 1 mm) contained a variety of ester-bound fatty acids (FA) representing a diverse bacterial population including cyanobacteria, sulphate reducers (SRB) and heterotrophs. Biomarkers for microeukaryotes detected in this layer included sterols, C-20 polyunsaturated FA and a highly branched isoprenoid, diagnostic for diatoms. Cyanobacteria were also indicated by the presence of a diagnostic set of mid-chain methylalkanes. C-28, to C-34 wax esters (WXE) present in relatively small amounts in the upper 3 mm of the mat are considered biomarkers for green non-sulphur bacteria. Ether-bound isoprenoids were also identified although in considerably lower abundance than ester-bound FA (approx. 1:l0). These complex ether lipids included archatol, hydroxyarchaeol and a C-40 tetraether, all in small amounts. After ether cleavage with boron tribromide, the major recovered isoprenyl was a C-30:1. This C(sub 30;1) yelded squalane after hydrogenation, a known geobiomarker for hypersaline environments in ancient oils and sediments. In this mat, it represents the dominant Archaeal population. The carbon isotopic composition of biomarker lipids were generally depleted relative to the bulk organic material (delta C-13 TOC -10%). Most

  4. Layered Thermohaline Convection in Hypersaline GeothermalSystems

    SciTech Connect

    Oldenburg, Curtis M.; Pruess, Karsten

    1997-01-05

    Thermohaline convection occurs in hypersaline geothermal systems due to thermal and salinity effects on liquid density. Because of its importance in oceanography, thermohaline convection in viscous liquids has received more attention than thermohaline convection in porous media. The fingered and layered convection patterns observed in viscous liquid thermohaline convection have been hypothesized to occur also in porous media. However, the extension of convective dynamics from viscous liquid systems to porous media systems is complicated by the presence of the solid matrix in porous media. The solid grains cause thermal retardation, hydrodynamic dispersion, and permeability effects. We present simulations of thermohaline convection in model systems based on the Salton Sea Geothermal System, California, that serve to point out the general dynamics of porous media thermohaline convection in the diffusive regime, and the effects of porosity and permeability, in particular. We use the TOUGH2 simulator with residual formulation and fully coupled solution technique for solving the strongly coupled equations governing thermohaline convection in porous media. We incorporate a model for brine density that takes into account the effects of NaCl and CaCl2. Simulations show that in forced convection, the increased pore velocity and thermal retardation in low-porosity regions enhances brine transport relative to heat transport. In thermohaline convection, the heat and brine transport are strongly coupled and enhanced transport of brine over heat cannot occur because buoyancy caused by heat and brine together drive the flow. Random permeability heterogeneity has a limited effect if the scale of flow is much larger than the scale of permeability heterogeneity. For the system studied here, layered thermohaline convection persists for more than one million years for a variety of initial conditions. Our simulations suggest that layered thermohaline convection is possible in

  5. Schistosomiasis in Lake Malaŵi villages.

    PubMed

    Madsen, Henry; Bloch, Paul; Makaula, Peter; Phiri, Happy; Furu, Peter; Stauffer, Jay R

    2011-06-01

    Historically, open shorelines of Lake Malaŵi were free from schistosome, Schistosoma haematobium, transmission, but this changed in the mid-1980s, possibly as a result of over-fishing reducing density of molluscivore fishes. Very little information is available on schistosome infections among people in lake-shore communities and therefore we decided to summarise data collected from 1998 to 2007. Detailed knowledge of the transmission patterns is essential to design a holistic approach to schistosomiasis control involving the public health, fisheries and tourism sectors. On Nankumba Peninsula, in the southern part of the lake, inhabitants of villages located along the shores of Lake Malaŵi have higher prevalence of S. haematobium infection than those living in inland villages. Overall prevalence (all age classes combined) of urinary schistosomiasis in 1998/1999 ranged from 10.2% to 26.4% in inland villages and from 21.0% to 72.7% in lakeshore villages; for school children prevalence of infection ranged from 15.3% to 57.1% in inland schools and from 56.2% to 94.0% in lakeshore schools. Inhabitants on the islands, Chizumulu and Likoma, also have lower prevalence of infection than those living in lakeshore villages on Nankumba Peninsula. This increased prevalence in lakeshore villages is not necessarily linked to transmission taking place in the lake itself, but could also be due to the presence of more numerous typical inland transmission sites (e.g., streams, ponds) being close to the lake. Temporal data witness of intense transmission in some lakeshore villages with 30-40% of children cleared from infection becoming reinfected 12 months later (also lakeshore village). The level of S. mansoni infection is low in the lakeshore communities. Findings are discussed in relation to fishing in the lake.

  6. Microbial Biomass and Activity Distribution in an Anoxic, Hypersaline Basin

    PubMed Central

    LaRock, Paul A.; Lauer, Ray D.; Schwarz, John R.; Watanabe, Kathleen K.; Wiesenburg, Denis A.

    1979-01-01

    The Orca Basin is a hypersaline depression in the northern Gulf of Mexico with anoxic conditions observed in the lower 200 m of the water column. Measurements of adenosine 5′-triphosphate, heterotrophic potential, and uridine uptake made above and across the interface into the anoxic zone revealed the presence of an active microbial population approximately 100 m above the interface. Biomass and activity decreased at and just below the interface but increased near the bottom, consistent with similar observations made in the Cariaco Trench. The maximum adenosine 5′-triphosphate concentration above the interface of 5.9 ng/liter (2,173 m) is about eight times greater than the value found in oxygenated waters of corresponding depth in the absence of an anoxic zone. The maximum adenosine 5′-triphosphate concentration in the anoxic zone is approximately 15 times greater than that found in oxygenated water of similar depth, suggesting anoxia will support the development of a larger bacterial population. Our findings suggest that autotrophic bacteria may be the dominant physiological group in the region just above the interface. PMID:16345355

  7. Performance of fungi in low temperature and hypersaline environments.

    PubMed

    Siegel, S M; Speitel, T W

    1976-01-01

    During the past ten years we have observed a broad array of stress capabilities in common fungi including ability to grow in aqueous ammonia and other alkaline solutions, in acids, in the presence of heavy metals, and in various salt media at low temperature. This report is concerned primarily with (a) the performance of Aspergillaceae in a variety of saturated salts, (b) distinctive roles for K+ and Rb+ ions, and (c) the lowest temperatures at which growth in nutrient brines has been observed, namely 267 degrees K in as little as 14 days. We also describe a novel solid medium based upon gelatin, glycerol and water in which fungal cultures growing at 248 degrees K can be directly examined under oil-immersion magnification. The performance capabilities of the fungi show that tolerance or adaptability to harsh and extreme physical-chemical environments cannot be considered a unique feature of prokaryotic life forms. Salt flats, brine pools and other natural hypersaline environments have long been recognized as real ecological niches harboring a range of biota from pseudomonad bacteria and green algae to specialized crustaceans. A notable omission in this ecological record is the fungi, although the group is known to include marine forms.

  8. Halotaxis of cyanobacteria in an intertidal hypersaline microbial mat.

    PubMed

    Kohls, Katharina; Abed, Raeid M M; Polerecky, Lubos; Weber, Miriam; de Beer, Dirk

    2010-03-01

    An intertidal hypersaline cyanobacterial mat from Abu Dhabi (United Arab Emirates) exhibited a reversible change in its surface colour within several hours upon changes in salinity of the overlying water. The mat surface was orange-reddish at salinities above 15% and turned dark green at lower salinities. We investigated this phenomenon using a polyphasic approach that included denaturing gradient gel electrophoresis, microscopy, high-performance liquid chromatography, hyperspectral imaging, absorption spectroscopy, oxygen microsensor measurements and modelling of salinity dynamics. Filaments of Microcoleus chthonoplastes, identified based on 16S rRNA sequencing and morphology, were found to migrate up and down when salinity was decreased below or increased above 15%, respectively, causing the colour change of the mat uppermost layer. Migration occurred in light and in the dark, and could be induced by different salts, not only NaCl. The influence of salinity-dependent and independent physico-chemical parameters, such as water activity, oxygen solubility, H2S, gravity and light, was excluded, indicating that the observed migration was due to a direct response to salt stress. We propose to term this salinity-driven cyanobacterial migration as 'halotaxis', a process that might play a vital role in the survival of cyanobacteria in environments exposed to continuous salinity fluctuations such as intertidal flats.

  9. Diversity of Heterotrophic Protists from Extremely Hypersaline Habitats.

    PubMed

    Park, Jong Soo; Simpson, Alastair G B

    2015-09-01

    Heterotrophic protists (protozoa) are a diverse but understudied component of the biota of extremely hypersaline environments, with few data on molecular diversity within halophile 'species', and almost nothing known of their biogeographic distribution. We have garnered SSU rRNA gene sequences for several clades of halophilic protozoa from enrichments from waters of >12.5% salinity from Australia, North America, and Europe (6 geographic sites, 25 distinct samples). The small stramenopile Halocafeteria was found at all sites, but phylogenies did not show clear geographic clustering. The ciliate Trimyema was recorded from 6 non-European samples. Phylogenies confirmed a monophyletic halophilic Trimyema group that included possible south-eastern Australian, Western Australian and North American clusters. Several halophilic Heterolobosea were detected, demonstrating that Pleurostomum contains at least three relatively distinct clades, and increasing known continental ranges for Tulamoeba peronaphora and Euplaesiobystra hypersalinica. The unclassified flagellate Palustrimonas, found in one Australian sample, proves to be a novel deep-branching alveolate. These results are consistent with a global distribution of halophilic protozoa groups (∼ morphospecies), but the Trimyema case suggests that is worth testing whether larger forms exhibit biogeographic phylogenetic substructure. The molecular detection/characterization of halophilic protozoa is still far from complete at the clade level, let alone the 'species level'. Copyright © 2015 Elsevier GmbH. All rights reserved.

  10. The biodiversity and ecology of Antarctic lakes: models for evolution.

    PubMed

    Laybourn-Parry, Johanna; Pearce, David A

    2007-12-29

    Antarctic lakes are characterised by simplified, truncated food webs. The lakes range from freshwater to hypersaline with a continuum of physical and chemical conditions that offer a natural laboratory in which to study evolution. Molecular studies on Antarctic lake communities are still in their infancy, but there is clear evidence from some taxonomic groups, for example the Cyanobacteria, that there is endemicity. Moreover, many of the bacteria have considerable potential as sources of novel biochemicals such as low temperature enzymes and anti-freeze proteins. Among the eukaryotic organisms survival strategies have evolved, among which dependence on mixotrophy in phytoflagellates and some ciliates is common. There is also some evidence of evolution of new species of flagellate in the marine derived saline lakes of the Vestfold Hills. Recent work on viruses in polar lakes demonstrates high abundance and high rates of infection, implying that they may play an important role in genetic exchange in these extreme environments.

  11. The study of Lake Urmia desiccation: morphometry impress

    NASA Astrophysics Data System (ADS)

    Moradi, Ayoub; Rasouli, Ali Akbar; Roostaei, Shahram

    2017-04-01

    Located in northwestern Iran, the hypersaline Lake Urmia has started a serious uninterrupted desiccation since 1995. The lake has lost about eight meters of water level and about 75% of water surface area during past 20 years. In particular, the lake water volume decrement has been accelerated in recent years. The importance of the Lake Urmia for human life in northwestern Iran, and its destructive effects on a vast region if totally dry up, demands comprehensive studies of the lake level fluctuations mechanism. According to literature review, the water volume of the lake behaves sometimes differently from the water storage of the whole basin. Our time series analysis using Land Data Assimilation Systems also confirms those differences within last decades. In other hand, many studies addressed the lake desiccation to climatic changes and/or anthropogenic influences such as excessive dam constructions in the watershed during last decades. As water leaves the lake only through evaporation, the fluctuation of evaporation has a distinctive role in the lake level variations. Dramatic decreament in the lake extent indicates of a special morphometry. The lake's morphometry has made it vulnerable to temperature and salinity changes. It strongly controls the lake's water heat capacity and water density. And, it therefore controls the rate of evaporation from water surface. We study the role of lake's morphometry on the lake desiccation. Although, the global climatic change is known as the primary reason for current droughts in the Middle East generally, our preliminary results show that the lake's morphometry is the main cause for the accelerating of water volume lost in Lake Urmia. In particular, after 2007, lake's water temperature and density show significant variations. Water heat capacity and evaporation rate are consistent with information of lake's hypsometry.

  12. Mechanisms of fenthion activation in rainbow trout (Oncorhynchus mykiss) acclimated to hypersaline environments

    SciTech Connect

    Lavado, Ramon Rimoldi, John M.; Schlenk, Daniel

    2009-03-01

    Previous studies in rainbow trout have shown that acclimation to hypersaline environments enhances the toxicity to thioether organophosphate and carbamate pesticides. In order to determine the role of biotransformation in this process, the metabolism of the thioether organophosphate biocide, fenthion was evaluated in microsomes from gills, liver and olfactory tissues in rainbow trout (Oncorhynchus mykiss) acclimated to freshwater and 17 per mille salinity. Hypersalinity acclimation increased the formation of fenoxon and fenoxon sulfoxide from fenthion in liver microsomes from rainbow trout, but not in gills or in olfactory tissues. NADPH-dependent and independent hydrolysis was observed in all tissues, but only NADPH-dependent fenthion cleavage was differentially modulated by hypersalinity in liver (inhibited) and gills (induced). Enantiomers of fenthion sulfoxide (65% and 35% R- and S-fenthion sulfoxide, respectively) were formed in liver and gills. The predominant pathway of fenthion activation in freshwater appears to be initiated through initial formation of fenoxon which may be subsequently converted to the most toxic metabolite fenoxon R-sulfoxide. However, in hypersaline conditions both fenoxon and fenthion sulfoxide formation may precede fenoxon sulfoxide formation. Stereochemical evaluation of sulfoxide formation, cytochrome P450 inhibition studies with ketoconazole and immunoblots indicated that CYP3A27 was primarily involved in the enhancement of fenthion activation in hypersaline-acclimated fish with limited contribution of FMO to initial sulfoxidation.

  13. The ICESat-2 Inland Water Height Data Product: Evaluation of Water Profiles Using High Altitude Photon Counting Lidar

    NASA Astrophysics Data System (ADS)

    Jasinski, M. F.; Stoll, J.; Cook, W. B.; Arp, C. D.; Birkett, C. M.; Brunt, K. M.; Harding, D. J.; Jones, B. M.; Markus, T.; Neumann, T.

    2015-12-01

    The Advanced Topographic Laser Altimeter System (ATLAS) on the Ice, Cloud, and Land Elevation Satellite (ICESat-2), scheduled to launch in 2017, is a low energy, high repetition rate, short pulse width, 532 nm lidar. Although primarily designed for icecap and sea ice monitoring, ATLAS also will record dense observations over Pan-Arctic inland water bodies throughout its designed three year life span. These measurements will offer improved understanding of the linkages between climate variability and Arctic hydrology including closure of the Pan-Arctic water balance. An ICESat-2 Inland Water Body Height Data Product is being developed consisting of along-track water surface height, slope, and roughness for each ATLAS strong beam, and also aspect and slope between adjacent beams. The data product will be computed for all global inland water bodies that are traversed by ICESat-2 during clear to moderately clear atmospheric conditions. While the domain of the ATL13 data product is global, the focus is on high-latitude terrestrial regions where the convergence of the ICESat-2 orbits will provide spatially dense observations. Water bodies will be identified primarily through the use of an "Inland Water Body Shape Mask". In preparation for the mission, the Multiple Beam Altimeter Lidar Experimental Lidar (MABEL), was built and flown during numerous high altitude experiments, observing a wide range of water targets. The current analysis examines several MABEL inland and near coastal coastal targets during 2012 to 2015, focusing on along track surface water height, light penetration into water under a range of atmospheric and water conditions. Sites include several Alaska lakes, the Chesapeake Bay, and the near shore Atlantic coast. Results indicate very good capability for retrieving along track surface water height and standard deviation and penetration depth. Overall, the MABEL data and subsequent analyses have demonstrated the feasibility of the ATL13 algorithm for

  14. Ocean waves monitor system by inland microseisms

    NASA Astrophysics Data System (ADS)

    Lin, L. C.; Bouchette, F.; Chang, E. T. Y.

    2016-12-01

    Microseisms are continuous ground oscillations which have been wildly introduced for decades. It is well known that the microseismicity in the frequency band from 0.05 to about 1 Hz partly results from ocean waves, which has been first explained by Longuet-Higgins [1950]. The generation mechanism for such a microseismicity is based on nonlinear wave-wave interactions which drive pressure pulses within the seafloor. The resulting ground pressure fluctuations yield ground oscillations at a double frequency (DF) with respect to that of current ocean waves. In order to understand the characteristics of DF microseisms associated with different wave sources, we aim to analyze and interpret the spectra of DF microseisms by using the simple spectrum method [Rabinovich, 1997] at various inland seismometer along the Taiwan coast. This is the first monitoring system of ocean waves observed by inland seismometers in Taiwan. The method is applied to identify wave sources by estimating the spectral ratios of wave induced microseisms associated with local winds and typhoons to background spectra. Microseism amplitudes above 0.2 Hz show a good correlation with wind-driven waves near the coast. Comparison of microseism band between 0.1 and 0.2 Hz with buoys in the deep sea shows a strong correlation of seismic amplitude with storm generated waves, implying that such energy portion originates in remote regions. Results indicate that microseisms observed at inland sites can be a potential tool for the tracking of typhoon displacements and the monitoring of extreme ocean waves in real time. Real- time Microseism-Ocean Waves Monitoring Website (http://mwave.droppages.com/) Reference Rabinovich, A. B. (1997) "Spectral analysis of tsunami waves: Separation of source and topography effects," J. Geophys. Res., Vol. 102, p. 12,663-12,676. Longuet-Higgins, M.S. (1950) "A theory of origin of microseisms," Philos. Trans. R. Soc., A. 243, pp. 1-35.

  15. Demonstration of antifreeze protein activity in Antarctic lake bacteria.

    PubMed

    Gilbert, Jack A; Hill, Philip J; Dodd, Christine E R; Laybourn-Parry, Johanna

    2004-01-01

    Antifreeze proteins (AFPs) are a structurally diverse group of proteins that have the ability to modify ice crystal structure and inhibit recrystallization of ice. AFPs are well characterized in fish and insects, but very few bacterial species have been shown to have AFP activity to date. Thirty eight freshwater to hypersaline lakes in the Ve