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Sample records for inland hypersaline lakes

  1. 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.

  2. 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

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

    PubMed

    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.

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

    PubMed

    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

  5. 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...

  6. Picophytoplankton predominance in hypersaline lakes (Transylvanian Basin, Romania).

    PubMed

    Somogyi, Boglárka; Vörös, Lajos; Pálffy, Károly; Székely, Gyöngyi; Bartha, Csaba; Keresztes, Zsolt Gyula

    2014-11-01

    The occurrence and importance of photoautotrophic picoplankton (PPP, cells with a diameter <2 μm) was studied along a trophic and salinity gradient in hypersaline lakes of the Transylvanian Basin (Romania). The studied lakes were found to be rich in PPP, with abundances (maximum 7.6 × 10(6) cells mL(-1)) higher than in freshwater and marine environments of similar trophic conditions. The contribution of PPP to the total phytoplankton biovolume did not decrease with increasing trophic state as it was generally found in other aquatic environments. Regardless of the trophic conditions, the contribution of PPP could reach 90-100 % in these hypersaline lakes. We hypothesized that the PPP predominance might be the result of the low grazing pressure, since heterotrophic nanoflagellates (the main grazers of PPP) were absent in the studied samples. There were significant differences in community composition among the lakes along the salinity gradient. CyPPP predominated in less saline waters (mainly below 5 %), while EuPPP were present along the entire salinity range (up to 18.7 %), dominating the phytoplankton between 3 and 13 % salinity. Above 13 % salinity, the phytoplankton was composed mainly of Dunaliella species.

  7. 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

  8. 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...

  9. 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.

  10. 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. PMID:26724953

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. 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. PMID:25932617

  18. 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.

  19. 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. PMID:26834712

  20. 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

  1. 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.

  2. 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. PMID:27070383

  3. 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.

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Great Lakes and inland waters is valid on all of the inland waters of the United States as defined in... waters of the United States, excluding the Great Lakes. Licenses and MMC endorsements with either a Great... line as defined in 33 CFR part 80, the applicant must complete an examination on the COLREGS or...

  5. 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

  6. 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

  7. 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...

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Microbial Diversity of the Hypersaline Sidi Ameur and Himalatt Salt Lakes of the Algerian Sahara.

    PubMed

    Boutaiba, Saad; Hacene, Hocine; Bidle, Kelly A; Maupin-Furlow, Julie A

    2011-10-01

    Microbial populations within hypersaline lakes often exhibit high activities of photosynthesis, dissimilatory sulphate reduction and other processes and, thus, can have profound impacts on biogeochemical cycles of carbon, nitrogen, sulphur and other important elements within arid lands. To further understand these types of ecosystems, the physicochemical and biological properties of Sidi Ameur and Himalatt Salt Lakes in the Algerian Sahara were examined and compared. Both lakes were relatively neutral in pH (7.2 to 7.4) and high in salt, at 12% and 20 % (w/v) salinity for Himalatt and Sidi Ameur Lakes, respectively, with dominant ions of sodium and chloride. The community compositions of microbes from all three domains (Bacteria, Archaea and Eukarya) were surveyed through the use of 16S and 18S ribosomal gene amplification and clone library clustering using amplified ribosomal DNA restriction analysis (ARDRA) in conjunction with DNA sequencing and analysis. A high level of microbial diversity, particularly among the bacteria of the Himalatt Salt Lake and archaea of Sidi Ameur Lake, was found within these environments. Representatives from all known halophilic bacterial phyla as well as 6 different genera of halophilic archaea were identified. Moreover, several apparently novel phylotypes among both archaea and bacteria were revealed.

  14. Microbial Diversity of the Hypersaline Sidi Ameur and Himalatt Salt Lakes of the Algerian Sahara

    PubMed Central

    Boutaiba, Saad; Hacene, Hocine; Bidle, Kelly A.; Maupin-Furlow, Julie A.

    2011-01-01

    Microbial populations within hypersaline lakes often exhibit high activities of photosynthesis, dissimilatory sulphate reduction and other processes and, thus, can have profound impacts on biogeochemical cycles of carbon, nitrogen, sulphur and other important elements within arid lands. To further understand these types of ecosystems, the physicochemical and biological properties of Sidi Ameur and Himalatt Salt Lakes in the Algerian Sahara were examined and compared. Both lakes were relatively neutral in pH (7.2 to 7.4) and high in salt, at 12% and 20 % (w/v) salinity for Himalatt and Sidi Ameur Lakes, respectively, with dominant ions of sodium and chloride. The community compositions of microbes from all three domains (Bacteria, Archaea and Eukarya) were surveyed through the use of 16S and 18S ribosomal gene amplification and clone library clustering using amplified ribosomal DNA restriction analysis (ARDRA) in conjunction with DNA sequencing and analysis. A high level of microbial diversity, particularly among the bacteria of the Himalatt Salt Lake and archaea of Sidi Ameur Lake, was found within these environments. Representatives from all known halophilic bacterial phyla as well as 6 different genera of halophilic archaea were identified. Moreover, several apparently novel phylotypes among both archaea and bacteria were revealed. PMID:21909172

  15. 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

  16. 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.

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

    USGS Publications Warehouse

    Fuller, Lori M.; Jodoin, Richard S.

    2016-01-01

    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.

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

    DOE PAGES

    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 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

  19. Halo(natrono)archaea isolated from hypersaline lakes utilize cellulose and chitin as growth substrates

    PubMed Central

    Sorokin, Dimitry Y.; Toshchakov, Stepan V.; Kolganova, Tatyana V.; Kublanov, Ilya V.

    2015-01-01

    Until recently, extremely halophilic euryarchaeota were considered mostly as aerobic heterotrophs utilizing simple organic compounds as growth substrates. Almost nothing is known on the ability of these prokaryotes to utilize complex polysaccharides, such as cellulose, xylan, and chitin. Although few haloarchaeal cellulases and chitinases were recently characterized, the analysis of currently available haloarchaeal genomes deciphered numerous genes-encoding glycosidases of various families including endoglucanases and chitinases. However, all these haloarchaea were isolated and cultivated on simple substrates and their ability to grow on polysaccharides in situ or in vitro is unknown. This study examines several halo(natrono)archaeal strains from geographically distant hypersaline lakes for the ability to grow on insoluble polymers as a sole growth substrate in salt-saturated mineral media. Some of them belonged to known taxa, while other represented novel phylogenetic lineages within the class Halobacteria. All isolates produced extracellular extremely salt-tolerant cellulases or chitinases, either cell-free or cell-bound. Obtained results demonstrate a presence of diverse populations of haloarchaeal cellulo/chitinotrophs in hypersaline habitats indicating that euryarchaea participate in aerobic mineralization of recalcitrant organic polymers in salt-saturated environments. PMID:26441877

  20. Halo(natrono)archaea isolated from hypersaline lakes utilize cellulose and chitin as growth substrates.

    PubMed

    Sorokin, Dimitry Y; Toshchakov, Stepan V; Kolganova, Tatyana V; Kublanov, Ilya V

    2015-01-01

    Until recently, extremely halophilic euryarchaeota were considered mostly as aerobic heterotrophs utilizing simple organic compounds as growth substrates. Almost nothing is known on the ability of these prokaryotes to utilize complex polysaccharides, such as cellulose, xylan, and chitin. Although few haloarchaeal cellulases and chitinases were recently characterized, the analysis of currently available haloarchaeal genomes deciphered numerous genes-encoding glycosidases of various families including endoglucanases and chitinases. However, all these haloarchaea were isolated and cultivated on simple substrates and their ability to grow on polysaccharides in situ or in vitro is unknown. This study examines several halo(natrono)archaeal strains from geographically distant hypersaline lakes for the ability to grow on insoluble polymers as a sole growth substrate in salt-saturated mineral media. Some of them belonged to known taxa, while other represented novel phylogenetic lineages within the class Halobacteria. All isolates produced extracellular extremely salt-tolerant cellulases or chitinases, either cell-free or cell-bound. Obtained results demonstrate a presence of diverse populations of haloarchaeal cellulo/chitinotrophs in hypersaline habitats indicating that euryarchaea participate in aerobic mineralization of recalcitrant organic polymers in salt-saturated environments. PMID:26441877

  1. 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.

  2. Cladosporinone, a new viriditoxin derivative from the hypersaline lake derived fungus Cladosporium cladosporioides.

    PubMed

    Liu, Yang; Kurtán, Tibor; Yun Wang, Chang; Han Lin, Wen; Orfali, Raha; Müller, Werner Eg; Daletos, Georgios; Proksch, Peter

    2016-09-01

    A new cytotoxic viriditoxin derivative, cladosporinone (1), along with the known viriditoxin (2) and two viriditoxin derivatives (3 and 4) were obtained from the fungus Cladosporium cladosporioides isolated from the sediment of a hypersaline lake in Egypt. The structure of the new compound (1) was determined by 1D and 2D NMR measurements as well as by high-resolution ESIMS and electronic circular dichroism spectroscopy. All isolated compounds were studied for their cytotoxicity against the murine lymphoma cell line L5187Y and for their antibiotic activity against several pathogenic bacteria. Viriditoxin (2) was the most active compound in both bioassays. Compound 1 also exhibited strong cytotoxicity against the murine lymphoma cell line L5187Y with an IC50 value of 0.88 μm, whereas its antibiotic activity was weak.

  3. 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.

  4. Organic Osmolytes in Aerobic Bacteria from Mono Lake, an Alkaline, Moderately Hypersaline Environment

    PubMed Central

    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. PMID:16535487

  5. 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.

  6. Methanosalsum natronophilum sp. nov., and Methanocalculus alkaliphilus sp. nov., haloalkaliphilic methanogens from hypersaline soda lakes.

    PubMed

    Sorokin, Dimitry Y; Abbas, Ben; Merkel, Alexander Y; Rijpstra, W Irene C; Damsté, Jaap S Sinninghe; Sukhacheva, Marina V; van Loosdrecht, Mark C M

    2015-10-01

    Two groups of haloalkaliphilic methanogenic archaea were dominating in enrichments from hypersaline soda lake sediments at pH 10. At moderate salt concentrations with formate or H2 as electron donor, methanogens belonging to the genus Methanocalculus were enriched, while at high salt concentrations with methylated substrates, a group related to Methanosalsum zhilinae was dominating. For both groups, several pure cultures were obtained including the type strains AMF2T for the Methanocalculus group and AME2T for the Methanosalsum group. The Methanocalculus group is characterized by lithoheterotrophic growth with either formate (preferable substrate) or H2 at moderate salinity up to 1.5-2 M total Na+ and obligate alkaliphilic growth with an optimum at pH 9.5. According to phylogenetic analysis, the group also includes closely related strains isolated previously from the low-salt alkaline Lonar Lake. The novel Methanosalsum group is characterized by high salt tolerance (up to 3.5 M total Na+) and obligate alkaliphilic growth with an optimum at pH 9.5. It has a typical methylotrophic substrate profile, utilizing methanol, methylamines and dimethyl sulfide (at low concentrations) as methanogenic substrates. On the basis of physiological and phylogenetic data, it is proposed that the two groups of soda lake methanogenic isolates are assigned into two novel species, Methanocalculus alkaliphilus sp. nov. (type strain AMF2T = DSM 24457T = UNIQEM U859T) and Methanosalsum natronophilum sp. nov. (type strain AME2T = DSM 24634T = NBRC 110091T).

  7. 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

    ...— (1) One year of service as a mate or first-class pilot while acting in the capacity of first mate of... mate inland or first-class pilot of Great Lakes and inland self-propelled vessels of unlimited tonnage... endorsement as mate or first-class pilot of Great Lakes and inland self-propelled vessels of 1,600 GRT or...

  8. 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.

  9. 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. PMID:27082142

  10. 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...

  11. 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...

  12. 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. PMID:26946176

  13. 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

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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.

  19. Magnesite formation by microbial activity: Evidence from a Miocene hypersaline lake

    NASA Astrophysics Data System (ADS)

    Sanz-Montero, M. E.; Rodríguez-Aranda, J. P.

    2012-07-01

    This paper provides an ancient analogue for biologically mediated magnesite in lacustrine hypersaline environments. Thin beds of massive to crudely laminated magnesitic marls occur interbedded with mudstone and evaporite facies deposited in a saline lake-mudflat sedimentary system during the Lower Miocene in the Madrid Basin, Central Spain. Exposure of this succession in a recently excavated tunnel and in collected cores offered a good opportunity to study magnesite precipitates that have been preserved in unaltered conditions by primary evaporitic minerals. Specifically, magnesite arranged as host matrix between and enclosed by displacive halite and glauberite crystals occurs closely associated with abundant microfossils embedded in sheets of organic matter, interpreted as the remains of extracellular polymeric substances (EPS). Even, many magnesite clots are seen to have resulted from the agglutination of fossilized bacterial bodies forming a biofilm. The close and pervasive association of microorganisms and magnesite is used as evidence that microbes played a fundamental role in the precipitation of this mineral. Additional traces of microorganisms and microbial activity observed in magnesite beds include the isotopic ratios in the carbonates, with the δ13C(PDB) value averaging - 6.2‰, the presence of carbonaceous film-like structures and the association with patchly-distributed pyrite and celestite minerals. On the basis of the combined sedimentological, mineralogical, chemical and morphological signatures of the magnesitic deposits, it is postulated that carbonate crystals precipitated in microbial mats. Magnesite crystals together with celestite, local barite, and/or pyrite have been also observed to replace silicate and sulphate minerals. It is suggested that magnesite precipitation was biochemically coupled with the early dissolution of the associated sedimentary minerals. Microbes may have used the associated minerals as source of energy and/or of

  20. Bacillus iranensis sp. nov., a moderate halophile from a hypersaline lake.

    PubMed

    Bagheri, M; Didari, M; Amoozegar, M A; Schumann, P; Sánchez-Porro, C; Mehrshad, M; Ventosa, A

    2012-04-01

    A Gram-positive, moderately halophilic rod, designated X5BT, was isolated from saline mud of the hypersaline lake Aran-Bidgol in Iran. Strain X5BT was a strictly aerobic, motile bacterium that produced ellipsoidal endospores at a central-subterminal position in non-swollen sporangia. The isolate grew at pH 7.0-10.0 (optimum pH 7.5), at 25-45 °C (optimum 35 °C) and with 2.5-15 % (w/v) NaCl (optimum 5-7.5 %). On the basis of 16S rRNA gene sequences, strain X5BT belonged to the genus Bacillus and showed highest similarity with Bacillus persepolensis HS136T (95.6 % 16S rRNA gene sequence similarity) and Bacillus salarius BH169T (95.5 %). The DNA G+C content was 42.4 mol%. The major cellular fatty acids were anteiso-C15:0 and iso-C15:0 and the polar lipid profile consisted of phosphatidylglycerol, diphosphatidylglycerol, three phospholipids and two glycolipids. The diamino acid found in the cell-wall peptidoglycan was meso-diaminopimelic acid and the isoprenoid quinones were MK-7 (92 %), MK-6 (6 %) and MK-5 (2 %). On the basis of phylogenetic, chemotaxonomic and phenotypic data, a novel species of the genus Bacillus is proposed, with the name Bacillus iranensis sp. nov. The type strain is X5BT (=IBRC 10446T=DSM 23995T).

  1. 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.

  2. Halorubrum halodurans sp. nov., an extremely halophilic archaeon isolated from a hypersaline lake.

    PubMed

    Corral, Paulina; de la Haba, Rafael R; Sánchez-Porro, Cristina; Ali Amoozegar, Mohammad; Thane Papke, R; Ventosa, Antonio

    2016-01-01

    Two extremely halophilic archaea, strains Cb34T and C170, belonging to the genus Halorubrum, were isolated from the brine of the hypersaline lake Aran-Bidgol in Iran. Cells of the two strains were motile, pleomorphic rods, stained Gram-variable and produced red-pigmented colonies. Strains Cb34T and C170 required 25 % (w/v) salts, pH 7.0 and 37 °C for optimal growth under aerobic conditions; 0.3 M Mg2+ was required. Cells of both isolates were lysed in distilled water and hypotonic treatment with < 10 % NaCl provoked cell lysis. Phylogenetic analysis based on 16S rRNA gene sequence similarities showed that these two strains were closely related to Halorubrum cibi B31T (98.8 %) and other members of the genus Halorubrum. In addition, studies based on the rpoB' gene revealed that strains Cb34T and C170 are placed among the species of Halorubrum and are closely related to Halorubrum cibi B31T, with rpoB' gene sequence similarity less than or equal to 95.7 %. The polar lipid patterns of both strains consisted of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and sulfated mannosyl glucosyl diether. The DNA G+C content was 62.1-62.4 mol%. DNA-DNA hybridization studies confirmed that strains Cb34T and C170 constitute a distinct species. Data obtained in this study show that the two strains represent a novel species, for which the name Halorubrum halodurans sp. nov. is proposed. The type strain is Cb34T ( = CECT 8745T = IBRC-M 10233T). PMID:26537912

  3. Halorubrum persicum sp. nov., an extremely halophilic archaeon isolated from sediment of a hypersaline lake.

    PubMed

    Corral, Paulina; de la Haba, Rafael R; Sánchez-Porro, Cristina; Amoozegar, Mohammad Ali; Papke, R Thane; Ventosa, Antonio

    2015-06-01

    An extremely halophilic archaeon belonging to the genus Halorubrum, strain C49T, was isolated from sediment of the hypersaline lake Aran-Bidgol in Iran. Phylogenetic analysis based on 16S rRNA gene sequence similarities showed that strain C49T was closely related to Halorubrum saccharovorum JCM 8865T (99.5 %) and other species of the genus Halorubrum. Studies based on multilocus sequence analysis revealed that strain C49T is placed among the species of Halorubrum; the strain constituted a defined branch in comparison with the type strains of species of Halorubrum, while the 16S rRNA gene sequence divergence could not define the status of the newly isolated strain. For optimum growth, strain C49T required 20 % (w/v) salts at pH 7.0 and 37 °C under aerobic conditions. Mg2+ was not required. The cells were pleomorphic rods, motile and stained Gram-variable. Colonies of the strain were pink. Hypotonic treatment with <12 % NaCl provoked cell lysis. The polar lipid pattern of strain C49T consisted of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester derived from both C20C20 and C20C25 archaeol, phosphatidylglycerol sulfate and sulfated mannosyl glucosyl diether. The DNA G+C content was 64.2 mol%. DNA-DNA hybridization studies and average nucleotide identity confirmed that strain C49T constitutes a distinct genospecies. Data obtained in this study show that strain C49T represents a novel species, for which the name Halorubrum persicum sp. nov. is proposed. The type strain is C49T ( = IBRC-M 10232T = JCM 30541T). PMID:25744586

  4. 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. PMID:27387660

  5. 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.

  6. 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.

  7. Planning and Management Guidelines for Inland Lake Property Owners.

    ERIC Educational Resources Information Center

    Van Dusen, Peter; Marsh, William M.

    This booklet is designed to assist prospective and established property owners in the selection, planning, and management of lake lands. It is organized into three parts: (1) selection and preparation of a building site; (2) property management; and (3) community development. These sections outline some basic guidelines for land development and…

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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.

  12. 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 to qualify an applicant for an endorsement as master of Great Lakes and inland steam or motor...

  13. 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

    ... 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...

  14. 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...

  15. 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...

  16. 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

  17. 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.

  18. 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. PMID:21602338

  19. 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

  20. Vertical physico-chemical gradients with distinct microbial communities in the hypersaline and heliothermal Lake Ursu (Sovata, Romania).

    PubMed

    Máthé, István; Borsodi, Andrea K; Tóth, Erika M; Felföldi, Tamás; Jurecska, Laura; Krett, Gergely; Kelemen, Zsolt; Elekes, Erzsébet; Barkács, Katalin; Márialigeti, Károly

    2014-05-01

    The effect of vertical physico-chemical stratification on the planktonic microbial community composition of the deep, hypersaline and heliothermal Lake Ursu (Sovata, Romania) was examined in this study. On site and laboratory measurements were performed to determine the physical and chemical variables of the lake water, and culture-based and cultivation-independent techniques were applied to identify the members of microbial communities. The surface of the lake was characterized by a low salinity water layer while the deepest region was extremely saline (up to 300 g/L salinity). Many parameters (e.g. photosynthetically active radiation, dissolved oxygen concentration, pH, redox potential) changed dramatically from 2 to 4 m below the water surface in conjunction with the increasing salinity values. The water temperature reached a maximum at this depth. At around 3 m depth, there was a water layer with high (bacterio) chlorophyll content dominated by Prosthecochloris vibrioformis, a phototrophic green sulfur bacterium. Characteristic microbial communities with various prokaryotic taxa were identified along the different environmental parameters present in the different water layers. Some of these bacteria were known to be heterotrophic and therefore may be involved in the decomposition of lake organic material (e.g. Halomonas, Idiomarina and Pseudoalteromonas) while others in the transformation of sulfur compounds (e.g. Prosthecochloris). Eukaryotic microorganisms identified by molecular methods in the lake water belonged to genera of green algae (Mantionella and Picochlorum), and were restricted mainly to the upper layers. PMID:24531691

  1. 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

  2. Vertical physico-chemical gradients with distinct microbial communities in the hypersaline and heliothermal Lake Ursu (Sovata, Romania).

    PubMed

    Máthé, István; Borsodi, Andrea K; Tóth, Erika M; Felföldi, Tamás; Jurecska, Laura; Krett, Gergely; Kelemen, Zsolt; Elekes, Erzsébet; Barkács, Katalin; Márialigeti, Károly

    2014-05-01

    The effect of vertical physico-chemical stratification on the planktonic microbial community composition of the deep, hypersaline and heliothermal Lake Ursu (Sovata, Romania) was examined in this study. On site and laboratory measurements were performed to determine the physical and chemical variables of the lake water, and culture-based and cultivation-independent techniques were applied to identify the members of microbial communities. The surface of the lake was characterized by a low salinity water layer while the deepest region was extremely saline (up to 300 g/L salinity). Many parameters (e.g. photosynthetically active radiation, dissolved oxygen concentration, pH, redox potential) changed dramatically from 2 to 4 m below the water surface in conjunction with the increasing salinity values. The water temperature reached a maximum at this depth. At around 3 m depth, there was a water layer with high (bacterio) chlorophyll content dominated by Prosthecochloris vibrioformis, a phototrophic green sulfur bacterium. Characteristic microbial communities with various prokaryotic taxa were identified along the different environmental parameters present in the different water layers. Some of these bacteria were known to be heterotrophic and therefore may be involved in the decomposition of lake organic material (e.g. Halomonas, Idiomarina and Pseudoalteromonas) while others in the transformation of sulfur compounds (e.g. Prosthecochloris). Eukaryotic microorganisms identified by molecular methods in the lake water belonged to genera of green algae (Mantionella and Picochlorum), and were restricted mainly to the upper layers.

  3. Halorussus amylolyticus sp. nov., isolated from an inland salt lake.

    PubMed

    Yuan, Pan-Pan; Ye, Wei-Tao; Pan, Jia-Xiang; Han, Dong; Zhang, Wen-Jiao; Cui, Heng-Lin

    2015-10-01

    A halophilic archaeal strain, YC93T, was isolated from Yuncheng salt lake in Shanxi Province, China. Cells were pleomorphic rods, stained Gram-negative and formed light-red-pigmented colonies on agar plates. Strain YC93T was able to grow at 25–50 °C (optimum 37 °C), with 1.4–4.8 M NaCl (optimum 2.0 M), with 0–1.0 M MgCl2 (optimum 0.05 M) and at pH 6.0–9.5 (optimum pH 7.0). Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 8 % (w/v). 16S rRNA gene sequence analysis revealed that strain YC93T had two dissimilar 16S rRNA genes both of which were phylogenetically related to those of the two recognized members of the genus Halorussus (93.0–95.3 % similarity). The rpoB′ gene of strain YC93T was phylogenetically related to the corresponding gene of Halorussus rarus TBN4T (91.3 % similarity) and Halorussus ruber YC25T (90.5 %). The major polar lipids were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and five glycolipids chromatographically identical to those of Halorussus rarus CGMCC 1.10122T. The DNA G+C content of strain YC93T was 64.6 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain YC93T represents a novel species of the genus Halorussus, for which the name Halorussus amylolyticus sp. nov. is proposed. The type strain is YC93T ( = CGMCC 1.12126T = JCM 18367T). PMID:26228463

  4. Inland fisheries

    USGS Publications Warehouse

    Cable, Louella E.; Shapiro, Sidney

    1971-01-01

    Today's inland commercial fisheries are small independent operational units widely dispersed on lakes, impoundments, and streams throughout the vast central plains. The problems of the fisheries are diverse and unique to local conditions. Inland fisheries are particularly important to the Nation in times of international conflict because they are distributed throughout the area and the fish can be easily harvested.

  5. Inputting history of heavy metals into the inland lake recorded in sediment profiles: Poyang Lake in China.

    PubMed

    Yuan, Guo-Li; Liu, Chen; Chen, Long; Yang, Zhongfang

    2011-01-15

    The temporal and spatial distribution of heavy metals (Cd, Hg, Pb, As and Cr) in Poyang Lake, the largest freshwater lake (3050 km(2)) in China, were studied based on the sedimentary profiles. For this purpose, eight sedimentary cores were selected which located at lake area, outfall of lake and the main branch rivers, respectively. High-resolution profiles with interval 2 cm were used for analyzing the concentration of metals, and the ages of them were determined by (210)Pb and (137)Cs isotopic dating. While studying the change of metals concentration with the age in profile, it is found that the concentration of them in sediments was influenced not only by the sources in history but also by the sediment types. Based on this detailed work, the inventory and burden of heavy metals per decade were estimated in lake area during the past 50 years. Significantly, rivers-contribution ratio per decade was estimated to distinguish each river's contribution of heavy metals into lake while river-flux in history and metals concentration in profiles were considered as calculating factors. So, our research provides a proof to well understand the sedimentary history and the inputting history of heavy metals from main rivers into an inland lake.

  6. 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. PMID:27045804

  7. 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. PMID:27617057

  8. 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

  9. 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.

  10. 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

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

    PubMed

    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

  12. 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.

  13. 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.

  14. 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...

  15. 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...

  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, 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...

  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, 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...

  18. 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...

  19. 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...

  20. 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

  1. 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) satellite-data 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

  2. 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.

  3. 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).

  4. Halanaeroarchaeum sulfurireducens gen. nov., sp. nov., the first obligately anaerobic sulfur-respiring haloarchaeon, isolated from a hypersaline lake.

    PubMed

    Sorokin, Dimitry Y; Kublanov, Ilya V; Yakimov, Mikhail M; Rijpstra, W Irene C; Sinninghe Damsté, Jaap S

    2016-06-01

    Anaerobic enrichments with acetate as electron donor and carbon source, and elemental sulfur as electron acceptor at 4 M NaCl using anaerobic sediments and brines from several hypersaline lakes in Kulunda Steppe (Altai, Russia) resulted in isolation in pure culture of four strains of obligately anaerobic haloarchae growing exclusively by sulfur respiration. Such metabolism has not yet been demonstrated in any known species of Halobacteria, and in the whole archaeal kingdom, acetate oxidation with sulfur as acceptor was not previously demonstrated. The four isolates had nearly identical 16S rRNA gene sequences and formed a novel genus-level branch within the family Halobacteriaceae. The strains had a restricted substrate range limited to acetate and pyruvate as electron donors and elemental sulfur as electron acceptor. In contrast to aerobic haloarchaea, the biomass of anaerobic isolates completely lacked the typical red pigments. Growth with acetate+sulfur was observed between 3-5 M NaCl and at a pH range from 6.7 to 8.0. The membrane core lipids were dominated by archaeols. On the basis of distinct physiological and phylogenetic data, the sulfur-respiring isolates represent a novel species of a new genus in the family Halobacteriaceae, for which the name Halanaeroarchaeaum sulfurireducens gen. nov., sp. nov. is proposed. The type strain of the type species is HSR2T (=JCM 30661T=UNIQEM U935T).

  5. Halanaeroarchaeum sulfurireducens gen. nov., sp. nov., the first obligately anaerobic sulfur-respiring haloarchaeon, isolated from a hypersaline lake.

    PubMed

    Sorokin, Dimitry Y; Kublanov, Ilya V; Yakimov, Mikhail M; Rijpstra, W Irene C; Sinninghe Damsté, Jaap S

    2016-06-01

    Anaerobic enrichments with acetate as electron donor and carbon source, and elemental sulfur as electron acceptor at 4 M NaCl using anaerobic sediments and brines from several hypersaline lakes in Kulunda Steppe (Altai, Russia) resulted in isolation in pure culture of four strains of obligately anaerobic haloarchae growing exclusively by sulfur respiration. Such metabolism has not yet been demonstrated in any known species of Halobacteria, and in the whole archaeal kingdom, acetate oxidation with sulfur as acceptor was not previously demonstrated. The four isolates had nearly identical 16S rRNA gene sequences and formed a novel genus-level branch within the family Halobacteriaceae. The strains had a restricted substrate range limited to acetate and pyruvate as electron donors and elemental sulfur as electron acceptor. In contrast to aerobic haloarchaea, the biomass of anaerobic isolates completely lacked the typical red pigments. Growth with acetate+sulfur was observed between 3-5 M NaCl and at a pH range from 6.7 to 8.0. The membrane core lipids were dominated by archaeols. On the basis of distinct physiological and phylogenetic data, the sulfur-respiring isolates represent a novel species of a new genus in the family Halobacteriaceae, for which the name Halanaeroarchaeaum sulfurireducens gen. nov., sp. nov. is proposed. The type strain of the type species is HSR2T (=JCM 30661T=UNIQEM U935T). PMID:27031647

  6. Exploration and characterization of agriculturally and industrially important haloalkaliphilic bacteria from environmental samples of hypersaline Sambhar lake, India.

    PubMed

    Sahay, Harmesh; Mahfooz, Sahil; Singh, Atul K; Singh, Surendra; Kaushik, Rajeev; Saxena, Anil K; Arora, Dilip K

    2012-11-01

    Screening of bacteria from Sambhar lake, an extreme hypersaline environment of India, led to the isolation of 93 haloalkaliphilic bacteria growing optimally in media with 2-25 % salt and 6-12 pH. Based on 16S rRNA gene sequences, 93 isolates were further categorized into 32 groups, with each group representing a different taxa belonging to 3 phyla (Firmicutes, Proteobacteria and Actinobacteria). Majority of the isolates (53.12 %) showed similarity with phylum Firmicutes which was followed by Proteobacteria (40.63 %) and Actinobacteria (6.25 %). The isolates belonging to 32 representative groups were further evaluated for the production of extracellular enzymes viz. amylase, cellulase, protease and xylanase, plant growth promoting attributes and BIOLOG™ substrate usage. Among all the isolates, xylanase producing isolates were in maximum (68 %) as compared to protease (56 %), cellulase (40 %), and amylase (37 %) producing strains. Similarly, among plant growth promoting activities, ammonia producing isolates were highest (56 %) when compared to those producing ACC deaminase (53 %), IAA (50 %), hydrogen cyanide (28 %), siderophore (21 %) and solubilizing P (34 %). Isolates showing enzymatic and PGP activities could be further utilized for promoting plant growth in saline affected area. PMID:22828794

  7. Saccharopolyspora halotolerans sp. nov., a halophilic actinomycete isolated from a hypersaline lake.

    PubMed

    Lv, Ling-Ling; Zhang, Yue-Feng; Xia, Zhan-Feng; Zhang, Jing-Jing; Zhang, Li-Li

    2014-10-01

    A novel actinomycete strain, designated TRM 45123(T), was isolated from a hypersaline habitat in Xinjiang Province (40° 20' N 90° 49' E), north-west China. The isolate was characterized using a polyphasic approach. 16S rRNA gene sequence analysis indicated that strain TRM 45123(T) belonged to the genus Saccharopolyspora and was closely related to Saccharopolyspora gloriosae (96.7% similarity). The G+C content of the DNA was 69.07 mol%. The isolate contained meso-diaminopimelic acid as the diagnostic diamino acid, and arabinose and ribose as the major whole-cell sugars. The diagnostic phospholipids were phosphatidylethanolamine, phosphatidylcholine and phosphatidylglycerol. The predominant menaquinone was MK-9(H4). The major fatty acids were iso-C16 : 0, anteiso-C17:0, iso-C15:0 and anteiso-C15:0. On the basis of the evidence from this polyphasic study, a novel species, Saccharopolyspora halotolerans sp. nov., is proposed. The type strain of Saccharopolyspora halotolerans is TRM 45123(T) ( = CCTCC AA 2013006(T) = DSM 45990(T)). PMID:25061064

  8. Saccharopolyspora halotolerans sp. nov., a halophilic actinomycete isolated from a hypersaline lake.

    PubMed

    Lv, Ling-Ling; Zhang, Yue-Feng; Xia, Zhan-Feng; Zhang, Jing-Jing; Zhang, Li-Li

    2014-10-01

    A novel actinomycete strain, designated TRM 45123(T), was isolated from a hypersaline habitat in Xinjiang Province (40° 20' N 90° 49' E), north-west China. The isolate was characterized using a polyphasic approach. 16S rRNA gene sequence analysis indicated that strain TRM 45123(T) belonged to the genus Saccharopolyspora and was closely related to Saccharopolyspora gloriosae (96.7% similarity). The G+C content of the DNA was 69.07 mol%. The isolate contained meso-diaminopimelic acid as the diagnostic diamino acid, and arabinose and ribose as the major whole-cell sugars. The diagnostic phospholipids were phosphatidylethanolamine, phosphatidylcholine and phosphatidylglycerol. The predominant menaquinone was MK-9(H4). The major fatty acids were iso-C16 : 0, anteiso-C17:0, iso-C15:0 and anteiso-C15:0. On the basis of the evidence from this polyphasic study, a novel species, Saccharopolyspora halotolerans sp. nov., is proposed. The type strain of Saccharopolyspora halotolerans is TRM 45123(T) ( = CCTCC AA 2013006(T) = DSM 45990(T)).

  9. 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.

  10. 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.

  11. 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

    ... inland steam or motor vessels of not more than 100 gross tons. 11.455 Section 11.455 Shipping COAST GUARD... steam or motor vessels of not more than 100 gross tons. (a) 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...

  12. 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

    ... inland steam or motor vessels of not more than 100 gross tons. 11.455 Section 11.455 Shipping COAST GUARD... steam or motor vessels of not more than 100 gross tons. (a) 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...

  13. 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

    ... 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...

  14. 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

    ... 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...

  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, 2010 CFR

    2010-10-01

    ... inland steam or motor vessels of not more than 200 gross tons. 11.452 Section 11.452 Shipping COAST GUARD... steam or motor vessels of not more than 200 gross tons. (a) 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...

  16. 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...

  17. 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

    ... 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...

  18. 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

    ... inland steam or motor vessels of not more than 200 gross tons. 11.452 Section 11.452 Shipping COAST GUARD... steam or motor vessels of not more than 200 gross tons. (a) 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...

  19. 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...

  20. 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

    ... inland steam or motor vessels of not more than 200 gross tons. 11.452 Section 11.452 Shipping COAST GUARD... steam or motor vessels of not more than 200 gross tons. (a) 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...

  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, 2013 CFR

    2013-10-01

    ... inland steam or motor vessels of not more than 100 gross tons. 11.455 Section 11.455 Shipping COAST GUARD... steam or motor vessels of not more than 100 gross tons. (a) 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 11.455 - 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

    ... inland steam or motor vessels of not more than 100 gross tons. 11.455 Section 11.455 Shipping COAST GUARD... steam or motor vessels of not more than 100 gross tons. (a) 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 11.452 - 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

    ... inland steam or motor vessels of not more than 200 gross tons. 11.452 Section 11.452 Shipping COAST GUARD... steam or motor vessels of not more than 200 gross tons. (a) 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...

  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, 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...

  5. 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...

  6. 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...

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. Effect of hypersaline and low lake conditions on ecological functioning of St Lucia estuarine system, South Africa: An overview 2002-2008

    NASA Astrophysics Data System (ADS)

    Cyrus, D. P.; Vivier, L.; Jerling, H. L.

    2010-03-01

    Lake St Lucia, the largest estuarine lake in Africa has been subjected to hypersaline conditions and low lake levels over the past eight years following the closure of its mouth due to drought in the region. This paper documents the physical changes through which the lake has passed and summarises the main findings of research undertaken on the three major biotic components that have been subjected to these conditions. A review of the anthropogenic impacts which have affected the system is provided. These indicate that in combination with drought conditions greater pressure is placed on the system that was the case in the historical past. Available data indicate that the current situation is not only impacting on the lake and its fauna but also on the adjacent nearshore marine environment, It is considered that the Meta area is potentially also under threat. Medium to long term relief possibilities that are under consideration are discussed in relation to the restructuring of something resembling the historically combined uMfolozi-St Lucia ecosystem that existed in the past. It is concluded that in the short term only two options are available to potentially provide relief for the system, the first is to breach the connection between the mouth and the sea. The second is to re-establish some form of more permanent connection, between uMfolozi and St Lucia.

  15. 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 Upper

  16. 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

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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

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

    PubMed

    Cruz-Rivera, Edwin; 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

  6. 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.

  7. 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.

  8. 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...

  9. 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

    ... steam or motor vessels of not more than 1600 gross tons. 11.444 Section 11.444 Shipping COAST GUARD... steam or motor vessels of not more than 1600 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...

  10. 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

    ... steam or motor vessels of not more than 200 gross tons. 11.454 Section 11.454 Shipping COAST GUARD... steam or motor vessels of not more than 200 gross tons. (a) 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...

  11. 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, 2011 CFR

    2011-10-01

    ... steam or motor vessels of not more than 1600 gross tons. 11.444 Section 11.444 Shipping COAST GUARD... steam or motor vessels of not more than 1600 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...

  12. 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

    ... steam or motor vessels of not more than 200 gross tons. 11.454 Section 11.454 Shipping COAST GUARD... steam or motor vessels of not more than 200 gross tons. (a) 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...

  13. 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...

  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-propelled vessels of less than 200 GRT. 11.454 Section 11.454 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN REQUIREMENTS FOR OFFICER ENDORSEMENTS Professional Requirements for National Deck...

  15. 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

    ... steam or motor vessels of not more than 1600 gross tons. 11.444 Section 11.444 Shipping COAST GUARD... steam or motor vessels of not more than 1600 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...

  16. 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

    ... steam or motor vessels of not more than 1600 gross tons. 11.444 Section 11.444 Shipping COAST GUARD... steam or motor vessels of not more than 1600 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...

  17. 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

    ... steam or motor vessels of not more than 200 gross tons. 11.454 Section 11.454 Shipping COAST GUARD... steam or motor vessels of not more than 200 gross tons. (a) 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 11.454 - 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

    ... steam or motor vessels of not more than 200 gross tons. 11.454 Section 11.454 Shipping COAST GUARD... steam or motor vessels of not more than 200 gross tons. (a) 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, 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...

  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. Spatial and Temporal Variations of Microbial Biodiversity at Hypersaline Microbial Mats

    NASA Astrophysics Data System (ADS)

    Gulecal, Y.; Unsal, N.; Temel, M.

    2014-12-01

    Hypersaline environments, such as hypersaline lakes are interesting sources with considerable potential for the isolation of extremophile microorganisms adapted to severe conditions. Biodiversity in such lakes (Dead Sea, the Great Salt Lake, the Solar Lake, the Soda Lake) varies due to differences in environmental conditions and specific lake characteristics such as local climate, lake size, water depth and lake water salt composition (Kamekura 1998; Sorokin et al. 2004). In this study area, Acigol Lake is an alkaline (pH:9), hypersaline lake located at Southwest Anatolia in Turkey. The aim of study was to determine the Archaea and Bacteria in microbial mats of hypersaline lacustrine environments. In conclusion, diagnostic biosignatures for methanogens and other archaeal groups within hypersaline microbial mats were identified through genomic DNA and lipid analyses.

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. 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

    The pH of aqueous environments is determined by the dominant buffer systems of the water, defined operationally as total alkalinity (TA). The major buffer systems in the modern ocean are carbonic and boric acids of which the species bicarbonate, carbonate and borate make up about 77%, 19% and 4% of the TA, respectively. During the course of seawater evaporation (e.g. lagoons) the residual brine loses considerable portion of the dissolved inorganic carbon (DIC) and carbonate alkalinity (CA) already at the early stages of evaporation. DIC and CA decrease due to massive precipitation of CaCO3, while total boron (TB) increases conservatively, turning borate to the dominant alkalinity species in marine derived brines. In the present work we assess the apparent dissociation constant value of boric acid (KB‧) in saline and hypersaline waters, using the Dead Sea (DS) as a case study. We explain the DS low pH (∼6.3) and the effect of the boric and carbonic acid pK‧-s on the behavior of the brine's buffer system, including the pH increase that results from brine dilution.

  7. 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.

  8. 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. PMID:25576792

  9. Complete genome sequence of 'Halanaeroarchaeum sulfurireducens' M27-SA2, a sulfur-reducing and acetate-oxidizing haloarchaeon from the deep-sea hypersaline anoxic lake Medee.

    PubMed

    Messina, Enzo; Sorokin, Dimitry Y; Kublanov, Ilya V; Toshchakov, Stepan; Lopatina, Anna; Arcadi, Erika; Smedile, Francesco; La Spada, Gina; La Cono, Violetta; Yakimov, Michail M

    2016-01-01

    Strain M27-SA2 was isolated from the deep-sea salt-saturated anoxic lake Medee, which represents one of the most hostile extreme environments on our planet. On the basis of physiological studies and phylogenetic positioning this extremely halophilic euryarchaeon belongs to a novel genus 'Halanaeroarchaeum' within the family Halobacteriaceae. All members of this genus cultivated so far are strict anaerobes using acetate as the sole carbon and energy source and elemental sulfur as electron acceptor. Here we report the complete genome sequence of the strain M27-SA2 which is composed of a 2,129,244-bp chromosome and a 124,256-bp plasmid. This is the second complete genome sequence within the genus Halanaeroarchaeum. We demonstrate that genome of 'Halanaeroarchaeum sulfurireducens' M27-SA2 harbors complete metabolic pathways for acetate and sulfur catabolism and for de novo biosynthesis of 19 amino acids. The genomic analysis also reveals that 'Halanaeroarchaeum sulfurireducens' M27-SA2 harbors two prophage loci and one CRISPR locus, highly similar to that of Kulunda Steppe (Altai, Russia) isolate 'H. sulfurireducens' HSR2(T). The discovery of sulfur-respiring acetate-utilizing haloarchaeon in deep-sea hypersaline anoxic lakes has certain significance for understanding the biogeochemical functioning of these harsh ecosystems, which are incompatible with life for common organisms. Moreover, isolations of Halanaeroarchaeum members from geographically distant salt-saturated sites of different origin suggest a high degree of evolutionary success in their adaptation to this type of extreme biotopes around the world. PMID:27182430

  10. 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.

  11. 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. PMID:19948847

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

    PubMed

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

    2011-02-01

    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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. 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

  19. 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. PMID:26547282

  20. 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.

  1. Synergy of multispectral and multisensors satellite observations to evaluate desert aerosol transport and impact of dust deposition on inland waters: study case of Lake Garda

    NASA Astrophysics Data System (ADS)

    Di Nicolantonio, Walter; Cazzaniga, Ilaria; Cacciari, Alessandra; Bresciani, Mariano; Giardino, Claudia

    2015-01-01

    The capabilities of different Earth Observation multispectral satellites are employed for detecting and tracking of desert dust coming from North Africa toward the Northern Italy area and for evaluating the impact of Saharan dust deposition in inland waters, such as those of Lake Garda. Absorbing and scattering spectral optical properties of desert aerosol in the atmospheric windows in the ultraviolet, visible-near-infrared, and infrared spectral ranges are exploited in the dust retrieval performed by OMI/Aura, MODIS/Terra-Aqua, and SEVIRI/MSG satellite sensors. Therefore, the direct link between dust deposition and increase in phytoplankton abundance has been assessed retrieving MERIS-based chlorophyll-a (chl-a) concentration for the desert dust events. Estimates of the increased chl-a in the lake have been derived with values in concentration from 30% to 170%. AERONET sun-photometer measurements, gravimetric particulate matter samplings, in situ chl-a concentration and surface temperature are employed to select events and assess the presence of desert dust and recognize a corresponding increase of the phytoplankton abundance in the analyzed inland waters. The improved observational features that will be provided by the next European Sentinels missions, namely Sentinel-2, 3, 4, 5P, together with MTG-I (Imager) and MTG-S (Sounder) will allow better monitoring atmospheric constituents and studying the environmental impacts of desert dust transport.

  2. 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

  3. 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. PMID:26699717

  4. 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

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

    PubMed

    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).

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

    PubMed

    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

  7. 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…

  8. Estimating phycocyanin pigment concentration in productive inland waters using Landsat measurements: a case study in Lake Dianchi.

    PubMed

    Sun, Deyong; Hu, Chuanmin; Qiu, Zhongfeng; Shi, Kun

    2015-02-01

    Using remote sensing reflectance (R(rs)(λ), sr(-1)) and phycocyanin (PC, mg m(-3)) pigment data as well as other bio-optical data collected from two cruises in September and December 2009 in Lake Dianchi (a typical plateau lake of China), we developed a practical approach to estimate PC concentrations that could be applied directly to Landsat measurements. The visible and near-IR bands as well as their band ratios of simulated Landsat data were used as inputs to the algorithms, where the algorithm coefficients for each Landsat sensor were determined through multivariate regressions. The coefficients of determination (R(2)) between the R(rs)-modeled and measured PC were all > 0.97 for the spectral bands corresponding to Landsat 8 OLI, Landsat 7 ETM + , Landsat 5 TM, and Landsat 4 TM, with mean absolute percentage errors (MAPE) < 10% for PC ranging between ~80 and 700 mg m(-3) (n = 14). The algorithms were further evaluated using an independent data set (n = 14), yielding larger but still acceptable MAPE (~30%) for PC ranging between ~80 and 500 mg m(-3). Application of the approach to Landsat 8 measurements over Lake Dianchi suggests potential use of the approach for periodical assessment of the lake's bloom conditions, yet its empirical nature together with the lack of specific narrow bands on Landsat sensors to explicitly account for the PC absorption around 625 nm calls for extra caution when applied to other eutrophic lakes.

  9. Estimating phycocyanin pigment concentration in productive inland waters using Landsat measurements: a case study in Lake Dianchi.

    PubMed

    Sun, Deyong; Hu, Chuanmin; Qiu, Zhongfeng; Shi, Kun

    2015-02-01

    Using remote sensing reflectance (R(rs)(λ), sr(-1)) and phycocyanin (PC, mg m(-3)) pigment data as well as other bio-optical data collected from two cruises in September and December 2009 in Lake Dianchi (a typical plateau lake of China), we developed a practical approach to estimate PC concentrations that could be applied directly to Landsat measurements. The visible and near-IR bands as well as their band ratios of simulated Landsat data were used as inputs to the algorithms, where the algorithm coefficients for each Landsat sensor were determined through multivariate regressions. The coefficients of determination (R(2)) between the R(rs)-modeled and measured PC were all > 0.97 for the spectral bands corresponding to Landsat 8 OLI, Landsat 7 ETM + , Landsat 5 TM, and Landsat 4 TM, with mean absolute percentage errors (MAPE) < 10% for PC ranging between ~80 and 700 mg m(-3) (n = 14). The algorithms were further evaluated using an independent data set (n = 14), yielding larger but still acceptable MAPE (~30%) for PC ranging between ~80 and 500 mg m(-3). Application of the approach to Landsat 8 measurements over Lake Dianchi suggests potential use of the approach for periodical assessment of the lake's bloom conditions, yet its empirical nature together with the lack of specific narrow bands on Landsat sensors to explicitly account for the PC absorption around 625 nm calls for extra caution when applied to other eutrophic lakes. PMID:25836166

  10. 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. PMID:26644942

  11. 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.

  12. 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...

  13. 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...

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

    2015-01-01

    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.

  19. 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.

  20. NIR-red reflectance-based algorithms for chlorophyll-a estimation in mesotrophic inland and coastal waters: Lake Kinneret case study.

    PubMed

    Yacobi, Yosef Z; Moses, Wesley J; Kaganovsky, Semion; Sulimani, Benayahu; Leavitt, Bryan C; Gitelson, Anatoly A

    2011-03-01

    A variety of models have been developed for estimating chlorophyll-a (Chl-a) concentration in turbid and productive waters. All are based on optical information in a few spectral bands in the red and near-infra-red regions of the electromagnetic spectrum. The wavelength locations in the models used were meticulously tuned to provide the highest sensitivity to the presence of Chl-a and minimal sensitivity to other constituents in water. But the caveat in these models is the need for recurrent parameterization and calibration due to changes in the biophysical characteristics of water based on the location and/or time of the year. In this study we tested the performance of NIR-red models in estimating Chl-a concentrations in an environment with a range of Chl-a concentrations that is typical for coastal and mesotrophic inland waters. The models with the same spectral bands as MERIS, calibrated for small lakes in the Midwest U.S., were used to estimate Chl-a concentration in the subtropical Lake Kinneret (Israel), where Chl-a concentrations ranged from 4 to 21 mg m(-3) during four field campaigns. A two-band model without re-parameterization was able to estimate Chl-a concentration with a root mean square error less than 1.5 mg m(-3). Our work thus indicates the potential of the model to be reliably applied without further need of parameterization and calibration based on geographical and/or seasonal regimes. PMID:21376361

  1. 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).

  2. [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. PMID:27228614

  3. [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.

  4. Possible origin of the high incidence of Clostridium botulinum type E in an inland bay (Green Bay of Lake Michigan).

    PubMed

    Bott, T L; Johnson, J; Foster, E M; Sugiyama, H

    1968-05-01

    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.

  5. 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. PMID:27498508

  6. 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.

  7. 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

  8. 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

  9. 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.

  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. PMID:10877781

  11. 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

  12. 77 FR 62435 - Inland Waterways Navigation Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-15

    ... Security FR Federal Register NPRM Notice of Proposed Rulemaking A. Regulatory History and Information On... Inland Waterways Navigation Regulations (77 FR 27007). We received 1 comment. Specifically, Lake Carriers... wake damage to vessels and shore structures (See 60 FR 35701-01). Because the Detroit River Light...

  13. Aquibacillus halophilus gen. nov., sp. nov., a moderately halophilic bacterium from a hypersaline lake, and reclassification of Virgibacillus koreensis as Aquibacillus koreensis comb. nov. and Virgibacillus albus as Aquibacillus albus comb. nov.

    PubMed

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

    2014-11-01

    A novel Gram-stain-positive, moderately halophilic bacterium, designated strain B6B(T), was isolated from the water of an Iranian hypersaline lake, Aran-Bidgol, and characterized taxonomically using a polyphasic approach. Cells of strain B6B(T) were rod-shaped, motile and produced ellipsoidal endospores in terminal positions in non-swollen sporangia. Strain B6B(T) was a strictly aerobic bacterium and catalase- and oxidase-positive. The strain was able to grow at NaCl concentrations of 0.5-20.0% (w/v), with optimum growth occurring at 10.0% (w/v) NaCl. The optimum temperature and pH for growth were 35 °C and pH 7.0. On the basis of 16S rRNA gene sequence analysis, strain B6B(T) was shown to belong to the phylum Firmicutes and its closest phylogenetic similarities were with the species Virgibacillus koreensis BH30097(T) (97.5%), Virgibacillus albus YIM 93624(T) (97.4%), Sediminibacillus halophilus EN8d(T) (96.8%), Sediminibacillus albus NHBX5(T) (96.6%), Virgibacillus carmonensis LMG 20964(T) (96.3%) and Paraliobacillus quinghaiensis YIM-C158(T) (96.0%), respectively. Phylogenetic analysis revealed that strain B6B(T), along with V. koreensis BH30097(T) and V. albus YIM 93624(T), clustered in a separate clade in the family Bacillaceae. The DNA G+C content of the novel isolate was 35.8 mol%. DNA-DNA hybridization experiments revealed low levels of relatedness between strain B6B(T)and V. koreensis BH30097(T) (13%) and V. albus YIM 93624(T) (33%). The major cellular fatty acid of strain B6B(T) was anteiso-C15 : 0 (75.1%) and its polar lipid pattern consisted of phosphatidylglycerol, diphosphatidylglycerol, an unknown phospholipid and an unknown glycolipid. The isoprenoid quinones were MK-7 (90%) and MK-6 (3%). The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. All of these features support the placement of isolate B6B(T) within the phylum Firmicutes. It is closely related to V. koreensis and V. albus, but with features that clearly

  14. 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.

  15. 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.

  16. Complete Genome Sequence of a New Megavirus Family Member Isolated from an Inland Water Lake for the First Time in India

    PubMed Central

    Chatterjee, Anirvan; Ali, Farhan; Bange, Disha

    2016-01-01

    We report here the isolation and complete genome sequencing of a large double-stranded DNA virus, Powai Lake megavirus, for the first time from India. The isolation of a large DNA virus with genome size >1 Mb from India further attests to the prevalence of Giant viruses in different environmental niches. PMID:27313286

  17. 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

  18. [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

  19. SEASAT altimetry for surface height of inland seas

    NASA Technical Reports Server (NTRS)

    Welker, J. E.

    1984-01-01

    The capability of spaceborne altimetry to record the level, or monitor changes in the level, of inland seas was assessed. SEASAT altimetry data from Lake Baikal in Siberia; the Caspian, Black, and Aral Seas in the southern Soviet Union; the Great Salt Lake in the United States; lakes and reservoirs in northwestern and central China; and snow cover in northwestern India and on the Tibetan Plateau were examined.

  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

    A total of 65 water-quality samples were collected during 2014 at 5 sites on 3 lakes—Buckeye Fairfield and Onion Island, Harsha Main and Campers, and MBSP Lake Erie beach. Four of the sites were bathing beaches and one site, Onion Island, was an offshore boater swim area. Concentrations of microcystin ranged from <0.10 to 240 µ/L and, as in 2013, the widest range was found at MBSP Lake Erie. At Buckeye Lake, microcystin concentrations were consistently high (greater than 20 µ/L), ranging from 23 to 81 µ/L. At Harsha Main and Campers, microcystin concentrations ranged from <0.10 to 15 µ/L. Saxitoxin was detected in four samples collected at MBSP Lake Erie. Throughout the 2014 season, the cyanobacterial community, as determined by molecular and microscopy methods, and the dominance associated with the highest microcystin concentrati

  1. 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, Rob; 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.

  2. CRUCIAL: Cryosat-2 Success over Inland Water and Land: Preliminary Inland Water Heights and Validation

    NASA Astrophysics Data System (ADS)

    Benveniste, J.; Moore, P.; Berry, P. A. M.; Balmbra, R.; Birkinshaw, S.; Bauer-Gottwein, P.; Dinardo, S.; Lucas, B.

    2014-12-01

    CRUCIAL is an ESA/STSE funded project investigating innovative land and inland water applications from Cryosat-2 with a forward-look component to the future Sentinel-3 mission. The fact that the Earth's land surface is, in general, a relatively poor reflector of Ku band energy, with the exceptions of inland water, salar and ice surfaces has enabled Earth-orbiting satellite radar altimeters to be used for land surface applications including mapping and measurement of river and lake systems. The high along-track sampling of Cryosat-2 altimeter in SAR mode (I8 KHz) offers the opportunity to recover high frequency signals over much of the Earth's land surface, enhancing the inland water height retrieval capability. Constraining this application is the limited availability of SAR Full Bit Rate (FBR) data from Cryosat-2 over these land surfaces; however, for Sentinel-3 the SAR mode will be deployed widely over land. This paper will summarise the CRUCIAL aims and objectives and present preliminary inland water heights from retracked Cryosat-2 altimetric waveforms, including results over Lake Malawi, the Amazon, Mekong and Brahmaputra with validation against in situ and other satellite data where possible.

  3. 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.

  4. 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)...

  5. 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.

  6. 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.

  7. Mortality of waterfowl on a hypersaline wetland as a result of salt encrustation

    SciTech Connect

    Wobeser, G.; Howard, J.

    1987-01-01

    Approximately 300 geese, primarily lesser Canada geese (Branta canadensis parvipes) were found unable to fly or dead on a small hypersaline lake (conductivity 77,000-90,000 mumhos/cm) in western Saskatchewan in September 1985. The birds were heavily encrusted with sodium sulfate crystals. Dead birds that were necropsied had aspirated lake water and had evidence of acute muscle degeneration. The live geese (155) were captured and moved to nearby freshwater wetlands where most apparently survived. Some birds died of severe myopathy after translocation. Five northern shovelers (Anas clypeata) were found encrusted with salt and unable to fly on the lake approximately 10 days later. Salt encrustation apparently occurred when rapid cooling of the lake resulted in supersaturation and crystallization of the dissolved salt. A local resident recalled similar events occurring on the lake in autumn on at least two other occasions during the past 50 yr.

  8. 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.

  9. 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.

  10. 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.

  11. Uranium in saline lakes of Northwestern Mongolia

    NASA Astrophysics Data System (ADS)

    Isupov, V. P.; Vladimirov, A. G.; Lyakhov, N. Z.; Shvartsev, S. L.; Ariunbileg, S.; Kolpakova, M. N.; Shatskaya, S. S.; Chupakhina, L. E.; Kuibida, L. V.; Moroz, E. N.

    2011-03-01

    Analysis of major- and trace-element compositions of water in hypersaline soda closed basin lakes of Northwestern Mongolia and Chuya basin (Gorny Altai) shows high enrichment in 238U (up to 1 mg/l). Proceeding from new data, uranium accumulation in water has been attributed to (i) location of the lakes and their watersheds in potential provinces of U-bearing rocks and (ii) uranium complexing with carbonate in presence of carbonate (bicarbonate) anions. Among the explored hypersaline soda lakes of the area, the greatest uranium resources are stored in Lake Hyargas Nuur (about 6000 ton).

  12. 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.

  13. 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.

  14. 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

  15. Bacillamides from a hypersaline microbial mat bacterium.

    PubMed

    Socha, Aaron M; Long, Richard A; Rowley, David C

    2007-11-01

    Chemical studies of a Bacillus endophyticus isolated from a Bahamian hypersaline microbial mat led to the isolation of bacillamides B and C, new tryptamide thiazole metabolites. Bioassay-guided fractionation using a HPLC-UV-MS bioassay technique enabled the detection of these trace fermentation products, and their total structures were elucidated by combined spectroscopic techniques.

  16. 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…

  17. Assembly-Driven Community Genomics of a Hypersaline Microbial Ecosystem

    PubMed Central

    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. PMID:23637883

  18. 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.

  19. 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

  20. Heterotrophic protists in hypersaline microbial mats and deep hypersaline basin water columns.

    PubMed

    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.

  1. 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.

  2. Methanogenesis in hypersaline ecosystems, and isolation and characterization of eight halophilic, methanogenic bacteria

    SciTech Connect

    Mathrani, I.M.

    1989-01-01

    The present ecological study of methanogenesis in hypersaline ecosystems focused on anaerobic sediment samples collected from several parts of the world. Inocula from solar salterns and natural hypersaline systems were examined for their ability to use catabolic substrates and for conditions which supported methanogenesis. Eight strictly anaerobic, halophilic, methane-producing Archaeobacteria were isolated from enrichment cultures inoculated with samples from hypersaline systems. The physiological and ecological characteristics of the isolates were examined and their phenotypic relatedness to each other and existing species of halophilic methanogens was discussed. The methanogenic, sulfate-reducing, and cellulolytic, halophilic bacteria from sediments of Lake Retba, Senegal were enumerated in depth profiles of sediment core samples. The catabolic substrates and environmental conditions for best growth of each bacterial group were determined. Trimethylamine, dimethylamine, methylamine, methanol, and sometimes dimethylsulfide were used as substrates for growth of methanogenic enrichment cultures and the eight isolates; hydrogen, acetate, or secondary alcohols did not support growth of methanogens. Hydrogen, formate, and lactate supported the growth of halophilic sulfate-reducing bacteria.

  3. 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.

  4. 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

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Service requirements for master of inland steam or motor... Deck Officers § 11.435 Service requirements for master of inland steam or motor vessels of any gross... (excluding the Great Lakes) steam or motor vessels of any gross tons is: (a) One year of service as...

  5. 46 CFR 11.435 - Service requirements for master of inland steam or motor vessels of any gross tons.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Service requirements for master of inland steam or motor... Deck Officers § 11.435 Service requirements for master of inland steam or motor vessels of any gross... (excluding the Great Lakes) steam or motor vessels of any gross tons is: (a) One year of service as...

  6. 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

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Service requirements for master of inland steam or motor... Deck Officers § 11.435 Service requirements for master of inland steam or motor vessels of any gross... (excluding the Great Lakes) steam or motor vessels of any gross tons is: (a) One year of service as...

  7. 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

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Service requirements for master of inland steam or motor... Deck Officers § 11.435 Service requirements for master of inland steam or motor vessels of any gross... (excluding the Great Lakes) steam or motor vessels of any gross tons is: (a) One year of service as...

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. Physiological Adaptation of a Nitrate-Storing Beggiatoa sp. to Diel Cycling in a Phototrophic Hypersaline Mat▿

    PubMed Central

    Hinck, Susanne; Neu, Thomas R.; Lavik, Gaute; Mussmann, Marc; de Beer, Dirk; Jonkers, Henk M.

    2007-01-01

    The aim of this study was to investigate the supposed vertical diel migration and the accompanying physiology of Beggiatoa bacteria from hypersaline microbial mats. We combined microsensor, stable-isotope, and molecular techniques to clarify the phylogeny and physiology of the most dominant species inhabiting mats of the natural hypersaline Lake Chiprana, Spain. The most dominant morphotype had a filament diameter of 6 to 8 μm and a length varying from 1 to >10 mm. Phylogenetic analysis by 16S rRNA gene comparison revealed that this type appeared to be most closely related (91% sequence identity) to the narrow (4-μm diameter) nonvacuolated marine strain MS-81-6. Stable-isotope analysis showed that the Lake Chiprana species could store nitrate intracellularly to 40 mM. The presence of large intracellular vacuoles was confirmed by fluorescein isothiocyanate staining and subsequent confocal microscopy. In illuminated mats, their highest abundance was found at a depth of 8 mm, where oxygen and sulfide co-occurred. However, in the dark, the highest Beggiatoa densities occurred at 7 mm, and the whole population was present in the anoxic zone of the mat. Our findings suggest that hypersaline Beggiatoa bacteria oxidize sulfide with oxygen under light conditions and with internally stored nitrate under dark conditions. It was concluded that nitrate storage by Beggiatoa is an optimal strategy to both occupy the suboxic zones in sulfidic sediments and survive the dark periods in phototrophic mats. PMID:17766448

  16. 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.

  17. 76 FR 11216 - Inland Waterways Users Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-01

    ....m. Agenda: The Board will be provided the status of the funding for inland navigation projects and studies and the status of the Inland Waterways Trust Fund, the funding status for Fiscal Year (FY)...

  18. 78 FR 72070 - Inland Waterways Users Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-02

    ... scheduled to adjourn at approximately 1:00 p.m. Agenda: The agenda will include the status of funding for inland navigation projects and studies, the status of the Inland Waterways Trust Fund, funding for...

  19. 77 FR 44222 - Inland Waterways Users Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-27

    ...:00 p.m. Agenda: The agenda will include the status of funding for inland navigation projects and studies and the status of the Inland Waterways Trust Fund, the funding status for Fiscal Year (FY)...

  20. 78 FR 44934 - Inland Waterways Users Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-25

    ... approximately 1:00 p.m. Agenda: The agenda will include the status of funding for inland navigation projects and studies, the status of the Inland Waterways Trust Fund, funding for Fiscal Year (FY) 2013 and 2014,...

  1. 75 FR 11870 - Inland Waterways Users Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-12

    .... BILLING CODE 3720-58-P ... 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: April 13, 2010. Location: The...

  2. 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.

  3. CRUCIAL: Cryosat-2 Success over Inland Water and Land

    NASA Astrophysics Data System (ADS)

    Moore, Philip; Berry, Philippa; Balmbra, Robert; Birkinshaw, Stephen; Kilsby, Chris; Bauer-Gottwein, Peter; Benveniste, Jerome; Dinardo, Salvatore; Lucas, Bruno

    2014-05-01

    CRUCIAL is an ESA/STSE funded project investigating innovative land and inland water applications from Cryosat-2 with a forward-look component to the future Sentinel-3 mission. The fact that the Earth's land surface is, in general, a relatively poor reflector of Ku band energy, with the exceptions of inland water, salar and ice surfaces has enabled Earth-orbiting satellite radar altimeters to be used for land surface applications including mapping and measurement of river and lake systems. Research with EnviSat Burst Echoes has shown that substantial high frequency information content is present at short spatial scales with a small bright reflecting patch at nadir, such as over inland water, able to dominate the returned echo. Onboard echo averaging of the previous generation of satellite radar altimeters therefore causes loss of significant amounts of information. The high along-track sampling of Cryosat-2 altimeter in SAR mode (I8 KHz) offers the opportunity to recover high frequency signals over much of the Earth's land surface, enhancing the inland water height retrieval capability. Constraining this application is the limited availability of SAR Full Bit Rate (FBR) data from Cryosat-2 over these land surfaces; however, for Sentinel-3 the SAR mode will be deployed widely over land. The Cryosat-2 CRUCIAL project will not only provide valuable data, but, as precursor of the Sentinel-3 SAR mode data, gives a valuable first look at this new measurement capability. This paper will summarise the CRUCIAL aims and objectives and showcase first results from retracking Cryosat-2 SAR and LRM waveforms over multiple inland water targets.

  4. CRUCIAL: Cryosat-2 success over inland water and land

    NASA Astrophysics Data System (ADS)

    Moore, Philip; Benveniste, Jérôme; Bauer-Gottwein, Peter; Dinardo, Salvatore; Lucas, Bruno Manuel; Berry, Philippa; Balmbra, Robert; Birkinshaw, Stephen

    CRUCIAL is an ESA/STSE funded project investigating innovative land and inland water applications from Cryosat-2 with a forward-look component to the future Sentinel-3 mission. The fact that the Earth’s land sur face is, in general, a relatively poor reflector of Ku band energy, with the exceptions of inland water, salar and ice surfaces has enabled Earth-orbiting satellite radar altimeters to be used for land surface applications including mapping and measurement of river and lake systems. Research with EnviSat Burst Echoes has shown that sub stantial high frequency information content is present at short spatial scales with a small bright reflecting patch at nadir, such as over inland water, able to dominate the returned echo. Onboard echo averaging of the previous generation of satellite radar altimeters therefore causes loss of significant amounts of information. The high along track sampling of Cryosat-2 altimeter in SAR mode (I8 KHz) offers the opportunity to recover high frequency signals over much of the Earth’s land surface, enhancing the inland water height retrieval capability. Constraining this application is the limited availability of SAR Full Bit Rate (FBR) data from Cryosat-2 over these land surfaces; however, for Sentinel-3 the SAR mode will be deployed widely over land. The Cryosat-2 CRUCIAL project will not only provide valuable data, but, as precursor of the Sentinel-3 SAR mode data, gives a valuable first look at this new measurement capability. This paper will summarise the CRUCIAL aims and objectives and showcase first results from retracking Cryosat-2 SAR and LRM waveforms over multiple inland water targets.

  5. Viruses Occur Incorporated in Biogenic High-Mg Calcite from Hypersaline Microbial Mats.

    PubMed

    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 (>10(10) 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 × 10(9) 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.

  6. Viruses Occur Incorporated in Biogenic High-Mg Calcite from Hypersaline Microbial Mats.

    PubMed

    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 (>10(10) 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 × 10(9) 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

  7. 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

  8. Predominance of biotic over abiotic formation of halogenated hydrocarbons in hypersaline sediments in Western Australia.

    PubMed

    Ruecker, A; Weigold, P; Behrens, S; Jochmann, M; Laaks, J; Kappler, A

    2014-08-19

    Volatile halogenated organic compounds (VOX) contribute to ozone depletion and global warming. There is evidence of natural VOX formation in many environments ranging from forest soils to salt lakes. Laboratory studies have suggested that VOX formation can be chemically stimulated by reactive Fe species while field studies have provided evidence for direct biological (enzymatic) VOX formation. However, the relative contribution of abiotic and biotic processes to global VOX budgets is still unclear. The goals of this study were to quantify VOX release from sediments from a hypersaline lake in Western Australia (Lake Strawbridge) and to distinguish between the relative contributions of biotic and abiotic VOX formation in microbially active and sterilized microcosms. Our experiments demonstrated that the release of organochlorines from Lake Strawbridge sediments was mainly biotic. Among the organochlorines detected were monochlorinated, e.g., chloromethane (CH3Cl), and higher chlorinated VOX compounds such as trichloromethane (CHCl3). Amendment of sediments with either Fe(III) oxyhydroxide (ferrihydrite) or a mixture of lactate/acetate or both ferrihydrite and lactate/acetate did not stimulate VOX formation. This suggests that although microbial Fe(III) reduction took place, there was no stimulation of VOX formation via Fe redox transformations or the formation of reactive Fe species under our experimental conditions.

  9. Predominance of biotic over abiotic formation of halogenated hydrocarbons in hypersaline sediments in Western Australia.

    PubMed

    Ruecker, A; Weigold, P; Behrens, S; Jochmann, M; Laaks, J; Kappler, A

    2014-08-19

    Volatile halogenated organic compounds (VOX) contribute to ozone depletion and global warming. There is evidence of natural VOX formation in many environments ranging from forest soils to salt lakes. Laboratory studies have suggested that VOX formation can be chemically stimulated by reactive Fe species while field studies have provided evidence for direct biological (enzymatic) VOX formation. However, the relative contribution of abiotic and biotic processes to global VOX budgets is still unclear. The goals of this study were to quantify VOX release from sediments from a hypersaline lake in Western Australia (Lake Strawbridge) and to distinguish between the relative contributions of biotic and abiotic VOX formation in microbially active and sterilized microcosms. Our experiments demonstrated that the release of organochlorines from Lake Strawbridge sediments was mainly biotic. Among the organochlorines detected were monochlorinated, e.g., chloromethane (CH3Cl), and higher chlorinated VOX compounds such as trichloromethane (CHCl3). Amendment of sediments with either Fe(III) oxyhydroxide (ferrihydrite) or a mixture of lactate/acetate or both ferrihydrite and lactate/acetate did not stimulate VOX formation. This suggests that although microbial Fe(III) reduction took place, there was no stimulation of VOX formation via Fe redox transformations or the formation of reactive Fe species under our experimental conditions. PMID:25073729

  10. 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.

  11. 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.

  12. 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

  13. Hypersalinity drives physiological and morphological changes in Limia perugiae (Poeciliidae).

    PubMed

    Weaver, Pablo F; Tello, Oscar; Krieger, Jonathan; Marmolejo, Arlen; Weaver, Kathleen F; Garcia, Jerome V; Cruz, Alexander

    2016-01-01

    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.

  14. 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

  15. Hypersalinity drives physiological and morphological changes in Limia perugiae (Poeciliidae).

    PubMed

    Weaver, Pablo F; Tello, Oscar; Krieger, Jonathan; Marmolejo, Arlen; Weaver, Kathleen F; Garcia, Jerome V; Cruz, Alexander

    2016-01-01

    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

  16. Sublethal toxicity of chlorpyrifos to salmonid olfaction after hypersaline acclimation.

    PubMed

    Maryoung, Lindley A; Blunt, Brian; Tierney, Keith B; Schlenk, Daniel

    2015-04-01

    Salmonid habitats can be impacted by several environmental factors, such as salinization, which can also affect salmonid tolerance to anthropogenic stressors, such as pesticides. Previous studies have shown that hypersaline acclimation enhances the acute toxicity of certain organophosphate and carbamate pesticides to euryhaline fish; however, sublethal impacts have been far less studied. The current study aims to determine how hypersaline acclimation and exposure to the organophosphate chlorpyrifos (CPF) impact salmonid olfaction. Combined acclimation and exposure to CPF was shown to impact rainbow trout olfaction at the molecular, physiological, and behavioral levels. Concurrent exposure to hypersalinity and 0.5μg/L CPF upregulated four genes (chloride intracellular channel 4, G protein zgc:101761, calcium calmodulin dependent protein kinase II delta, and adrenergic alpha 2C receptor) that inhibit olfactory signal transduction. At the physiological level, hypersalinity and chlorpyrifos caused a decrease in sensory response to the amino acid l-serine and the bile salt taurocholic acid. Combined acclimation and exposure also negatively impacted behavior and reduced the avoidance of a predator cue (l-serine). Thus, acclimation to hypersaline conditions and exposure to environmentally relevant concentrations of chlorpyrifos caused an inhibition of olfactory signal transduction leading to a decreased response to odorants and impairment of olfactory mediated behaviors.

  17. Temporal stability and origin of chemoclines in the deep hypersaline anoxic Urania basin

    NASA Astrophysics Data System (ADS)

    Goldhammer, Tobias; Schwärzle, Andreas; Aiello, Ivano W.; Zabel, Matthias

    2015-06-01

    Submarine brine lakes feature sharp and persistent concentration gradients between seawater and brine, though these should be smoothed out by free diffusion in open ocean settings. The anoxic Urania basin of the eastern Mediterranean contains an ultrasulfidic, hypersaline brine of Messinian origin above a thick layer of suspended sediments. With a dual modeling approach we reconstruct its contemporary stratification by geochemical solute transport fundamentals and show that thermal convection is required to maintain mixing in the brine and mud layer. The origin of the Urania basin stratification was dated to 1650 years B.P., which may be linked to a major earthquake in the region. The persistence of the chemoclines may be key to the development of diverse and specialized microbial communities. Ongoing thermal convection in the fluid mud layer may have important yet unresolved consequences for sedimentological and geochemical processes, also in similar environments.

  18. Radar Altimetry for Inland Water: Current and Potential Applications

    NASA Astrophysics Data System (ADS)

    Tarpanelli, Angelica; Brocca, Luca; Barbetta, Silvia; Moramarco, Tommaso; da Silva, Joecila Santos; Calmant, Stephane

    2015-12-01

    Apart from oceans and ice-sheets, radar altimeters are shown by a plethora of works to be of considerable interest in monitoring inland water bodies such as rivers, lakes, wetlands and floodplains. More than a decade of research on the application in the field of continental hydrology has demonstrated the advantages of providing global coverage, regular temporal sampling and short delivery delays, especially via the acquisition of numerous useful measurements over ungauged areas. With the aim to investigate the benefits that can be achieved by Sentinel-3 mission, two applications are here shown for selected pilot rivers and the results on discharge estimation are analyzed and discussed in terms of performance measures.

  19. 33 CFR 162.120 - Harbors on Lake Michigan.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., White Lake, Pentwater, Ludington, Manistee, Portage Lake (Manistee County), Frankfort, Charlevoix, and... 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...

  20. 33 CFR 162.120 - Harbors on Lake Michigan.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., White Lake, Pentwater, Ludington, Manistee, Portage Lake (Manistee County), Frankfort, Charlevois, and... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Harbors on Lake Michigan. 162.120...) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.120 Harbors on Lake...

  1. 33 CFR 162.120 - Harbors on Lake Michigan.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., White Lake, Pentwater, Ludington, Manistee, Portage Lake (Manistee County), Frankfort, Charlevoix, and... 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...

  2. 33 CFR 162.120 - Harbors on Lake Michigan.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., White Lake, Pentwater, Ludington, Manistee, Portage Lake (Manistee County), Frankfort, Charlevoix, and... 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...

  3. Microbial diversity of hypersaline environments: a metagenomic approach.

    PubMed

    Ventosa, Antonio; de la Haba, Rafael R; Sánchez-Porro, Cristina; Papke, R Thane

    2015-06-01

    Recent studies based on metagenomics and other molecular techniques have permitted a detailed knowledge of the microbial diversity and metabolic activities of microorganisms in hypersaline environments. The current accepted model of community structure in hypersaline environments is that the square archaeon Haloquadratum waslbyi, the bacteroidete Salinibacter ruber and nanohaloarchaea are predominant members at higher salt concentrations, while more diverse archaeal and bacterial taxa are observed in habitats with intermediate salinities. Additionally, metagenomic studies may provide insight into the isolation and characterization of the principal microbes in these habitats, such as the recently described gammaproteobacterium Spiribacter salinus. PMID:26056770

  4. 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.

  5. 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.

  6. 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

  7. 75 FR 57264 - Inland Waterways Users Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-20

    ... permitted by the committee. Brenda S. Bowen, Army Federal Register Liaison Officer. BILLING CODE 3720-58-P ... 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: October 20, 2010. Location: The...

  8. 77 FR 69447 - Inland Waterways Users Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-19

    ...:00 p.m. Agenda: The agenda will include the status of funding for inland navigation projects and..., status of the Olmsted Locks and Dam Project, the Board's annual report for 2012 and the project investment recommendations, along with updates of the Inland Marine Transportation System (IMTS) Levels...

  9. 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…

  10. 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

    2012-01-01

    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

  11. 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.

  12. Metagenomic and lipid analyses reveal a diel cycle in a hypersaline microbial ecosystem.

    PubMed

    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

    2015-12-01

    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. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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...

  18. 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...) 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,...

  19. 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...

  20. 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... 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...

  1. 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... 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...

  2. 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... 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...

  3. 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... 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...

  4. 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

  5. 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

  6. The spectral signature analysis of inland and coastal water bodies acquired from field spectroradiometric measurements

    NASA Astrophysics Data System (ADS)

    Papoutsa, Christiana; Akylas, Evangelos; Hadjimitsis, Diofantos

    2013-08-01

    The main goal of this research is to examine the optical properties of different water bodies such as coastal water; oligotrophic and eutrophic inland water by observing their spectral signatures. Spectral profiles of sampling points, which correspond to water bodies with different water quality characteristics, are extracted and analyzed. Field spectroscopy is a very important tool giving critical information for the comprehension of spectral signatures of different water bodies. Field spectroradiometric measurements can assist to improve or develop new algorithms and methodology enables to classify several water bodies according to their water quality characteristics using remotely sensed data. Field spectroradiometric data presented at this study were obtained for inland water in Asprokremmos Dam, Paphos District/Cyprus; in Larnaca's Salt Lake, Larnaca District/Cyprus; and in Karla Lake, Volos District/Greece and for coastal water in Zugi-Vasilikos-Old Harbour, Limassol District/Cyprus.

  7. 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...

  8. 33 CFR 89.25 - Waters upon which Inland Rules 9(a)(ii), 14(d), and 15(b) apply.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Point. (g) Flint River. (h) Chattachoochee River. (i) The Apalachicola River above its confluence with...), and 15(b) apply. Inland Rules 9(a)(ii), 14(d), and 15(b) apply on the Great Lakes, the Western Rivers, and the following specified waters: (a) Tennessee-Tombigbee Waterway. (b) Tombigbee River. (c)...

  9. 33 CFR 89.25 - Waters upon which Inland Rules 9(a)(ii), 14(d), and 15(b) apply.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Point. (g) Flint River. (h) Chattachoochee River. (i) The Apalachicola River above its confluence with...), and 15(b) apply. Inland Rules 9(a)(ii), 14(d), and 15(b) apply on the Great Lakes, the Western Rivers, and the following specified waters: (a) Tennessee-Tombigbee Waterway. (b) Tombigbee River. (c)...

  10. 33 CFR 89.25 - Waters upon which Inland Rules 9(a)(ii), 14(d), and 15(b) apply.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Point. (g) Flint River. (h) Chattachoochee River. (i) The Apalachicola River above its confluence with...), and 15(b) apply. Inland Rules 9(a)(ii), 14(d), and 15(b) apply on the Great Lakes, the Western Rivers, and the following specified waters: (a) Tennessee-Tombigbee Waterway. (b) Tombigbee River. (c)...

  11. 33 CFR 89.25 - Waters upon which Inland Rules 9(a)(ii), 14(d), and 15(b) apply.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Point. (g) Flint River. (h) Chattachoochee River. (i) The Apalachicola River above its confluence with...), and 15(b) apply. Inland Rules 9(a)(ii), 14(d), and 15(b) apply on the Great Lakes, the Western Rivers, and the following specified waters: (a) Tennessee-Tombigbee Waterway. (b) Tombigbee River. (c)...

  12. 33 CFR 89.25 - Waters upon which Inland Rules 9(a)(ii), 14(d), and 15(b) apply.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Point. (g) Flint River. (h) Chattachoochee River. (i) The Apalachicola River above its confluence with...), and 15(b) apply. Inland Rules 9(a)(ii), 14(d), and 15(b) apply on the Great Lakes, the Western Rivers, and the following specified waters: (a) Tennessee-Tombigbee Waterway. (b) Tombigbee River. (c)...

  13. 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...

  14. 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.

  15. 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

    ... 46 Shipping 1 2010-10-01 2010-10-01 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...

  16. 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

    ... 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...

  17. 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

    ... 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... for master or mate of vessels of less than 200 GRT are issued in 50 GRT increments based on...

  18. 46 CFR 11.450 - Tonnage limitations and qualifying requirements for endorsements as master or mate of Great Lakes...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 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...

  19. 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

    ... 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...

  20. 33 CFR 162.134 - Connecting waters from Lake Huron to Lake Erie; traffic rules.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Connecting waters from Lake Huron to Lake Erie; traffic rules. 162.134 Section 162.134 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.134 Connecting waters from...

  1. 33 CFR 162.140 - Connecting waters from Lake Huron to Lake Erie; miscellaneous rules.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 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 WATERWAYS NAVIGATION REGULATIONS § 162.140 Connecting waters...

  2. 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 WATERWAYS NAVIGATION REGULATIONS § 162.140 Connecting waters...

  3. 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 WATERWAYS NAVIGATION REGULATIONS § 162.140 Connecting waters...

  4. 33 CFR 162.140 - Connecting waters from Lake Huron to Lake Erie; miscellaneous rules.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 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 WATERWAYS NAVIGATION REGULATIONS § 162.140 Connecting waters...

  5. 33 CFR 162.140 - Connecting waters from Lake Huron to Lake Erie; miscellaneous rules.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 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 WATERWAYS NAVIGATION REGULATIONS § 162.140 Connecting waters...

  6. 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.

  7. 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.

  8. 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

  9. Improved Atmospheric Correction for AVIRIS Spectra from Inland Waters

    NASA Technical Reports Server (NTRS)

    Gastil, Mary; Melack, John M.

    1998-01-01

    Remote sensing reflectance (Rrs) cannot be measured directly. Comparison of Rrs calculated from field measurements to Rrs calculated from AVIRIS spectra and the atmospheric radiative transfer model modtran provides a measure of the accuracy of our method. That and other comparisons are presented here as a validation of a method of retrieving Rrs from inland waters from AVIRIS radiance. The method of collecting field measurements for Rrs is described in Hamilton, 1993. Retrieval of Rrs from AVIRIS using modtran was developed from Carder, 1993. AVIRIS radiance is reduced by the path radiance modeled by modtran and divided by one-way transmission. Skylight, modeled by modtran, specularly reflected from the lake surface, is then subtracted from this radiance, leaving only that radiance which has come from under water. This water-leaving radiance is then normalized by the downwelling irradiance incident at the surface as modeled by modtran. Our improved retrieval of Rrs has allowed us to fit a single curve to a set of 134 pairs of AVIRIS Rrs and measured chlorophyll gathered on eight experiments at Mono Lake. Previously, spectra from different surveys varied more due to lingering atmospheric effects and/or radiometric calibration imprecision than they varied due to chlorophyll.

  10. 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.

  11. 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. PMID:22748091

  12. 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.

  13. Cyanobacterial diversity and halotolerance in a variable hypersaline environment.

    PubMed

    Kirkwood, Andrea E; Buchheim, Julie A; Buchheim, Mark A; Henley, William J

    2008-04-01

    The Great Salt Plains (GSP) in north-central Oklahoma, USA is an expansive salt flat (approximately 65 km(2)) that is part of the federally protected Salt Plains National Wildlife Refuge. The GSP serves as an ideal environment to study the microbial diversity of a terrestrial, hypersaline system that experiences wide fluctuations in freshwater influx and diel temperature. Our study assessed cyanobacterial diversity at the GSP by focusing on the taxonomic and physiological diversity of GSP isolates, and the 16S rRNA phylogenetic diversity of isolates and environmental clones from three sites (north, central, and south). Taxonomic diversity of isolates was limited to a few genera (mostly Phormidium and Geitlerinema), but physiological diversity based on halotolerance ranges was strikingly more diverse, even between strains of the same phylotype. The phylogenetic tree revealed diversity that spanned a number of cyanobacterial lineages, although diversity at each site was dominated by only a few phylotypes. Unlike other hypersaline systems, a number of environmental clones from the GSP were members of the heterocystous lineage. Although a number of cyanobacterial isolates were close matches with prevalent environmental clones, it is not certain if these clones reflect the same halotolerance ranges of their matching isolates. This caveat is based on the notable disparities we found between strains of the same phylotype and their inherent halotolerance. Our findings support the hypothesis that variable or poikilotrophic environments promote diversification, and in particular, select for variation in ecotype more than phylotype. PMID:17653786

  14. 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

  15. 75 FR 41987 - Inland Navigation Rules; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-20

    ...-1565 Scott.R.Medeiros@uscg.mil . SUPPLEMENTARY INFORMATION: In FR doc 2010-8532 appearing on page 20294... 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...

  16. 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

  17. 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.

  18. 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

  19. Urmia Lake (Northwest Iran): a brief review

    PubMed Central

    Eimanifar, Amin; Mohebbi, Feridon

    2007-01-01

    Lake Urmia (or Ormiyeh) is one of the largest hypersaline lakes in the world and the habitat of a unique bisexual Artemia species (A. urmiana). Despite this, and several other values of the lake, little literature on it has been published. The present paper is an attempt to provide a brief review on various aspects of the lake. Urmia Lake, located in northwestern Iran, is an oligotrophic lake of thalassohaline origin with a total surface area between 4750 and 6100 km2 and a maximum depth of 16 m at an altitude of 1250 m. The lake is divided into north and south parts separated by a causeway in which a 1500-m gap provides little exchange of water between the two parts. Due to drought and increased demands for agricultural water in the lake's basin, the salinity of the lake has risen to more than 300 g/L during recent years, and large areas of the lake bed have been desiccated. Therefore, management and conservation of this incomparable ecosystem should be considered to improve the current condition by fisheries research institutes. PMID:17506897

  20. 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.

  1. 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.

  2. Comprehensive lake dynamics mapping at continental scales using Landsat 8

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  3. 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.

  4. 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.

  5. Remote chlorophyll-a estimates for inland waters based on a cluster-based classification.

    PubMed

    Shi, Kun; Li, Yunmei; Li, Lin; Lu, Heng; Song, Kaishan; Liu, Zhonghua; Xu, Yifan; Li, Zuchuan

    2013-02-01

    Accurate estimates of chlorophyll-a concentration (Chl-a) from remotely sensed data for inland waters are challenging due to their optical complexity. In this study, a framework of Chl-a estimation is established for optically complex inland waters based on combination of water optical classification and two semi-empirical algorithms. Three spectrally distinct water types (Type I to Type III) are first identified using a clustering method performed on remote sensing reflectance (R(rs)) from datasets containing 231 samples from Lake Taihu, Lake Chaohu, Lake Dianchi, and Three Gorges Reservoir. The classification criteria for each optical water type are subsequently defined for MERIS images based on the spectral characteristics of the three water types. The criteria cluster every R(rs) spectrum into one of the three water types by comparing the values from band 7 (central band: 665 nm), band 8 (central band: 681.25 nm), and band 9 (central band: 708.75 nm) of MERIS images. Based on the water classification, the type-specific three-band algorithms (TBA) and type-specific advanced three-band algorithm (ATBA) are developed for each water type using the same datasets. By pre-classifying, errors are decreased for the two algorithms, with the mean absolute percent error (MAPE) of TBA decreasing from 36.5% to 23% for the calibration datasets, and from 40% to 28% for ATBA. The accuracy of the two algorithms for validation data indicates that optical classification eliminates the need to adjust the optimal locations of the three bands or to re-parameterize to estimate Chl-a for other waters. The classification criteria and the type-specific ATBA are additionally validated by two MERIS images. The framework of first classifying optical water types based on reflectance characteristics and subsequently developing type-specific algorithms for different water types is a valid scheme for reducing errors in Chl-a estimation for optically complex inland waters.

  6. An improved atmospheric correction algorithm for applying MERIS data to very turbid inland waters

    NASA Astrophysics Data System (ADS)

    Jaelani, Lalu Muhamad; Matsushita, Bunkei; Yang, Wei; Fukushima, Takehiko

    2015-07-01

    Atmospheric correction (AC) is a necessary process when quantitatively monitoring water quality parameters from satellite data. However, it is still a major challenge to carry out AC for turbid coastal and inland waters. In this study, we propose an improved AC algorithm named N-GWI (new standard Gordon and Wang's algorithms with an iterative process and a bio-optical model) for applying MERIS data to very turbid inland waters (i.e., waters with a water-leaving reflectance at 864.8 nm between 0.001 and 0.01). The N-GWI algorithm incorporates three improvements to avoid certain invalid assumptions that limit the applicability of the existing algorithms in very turbid inland waters. First, the N-GWI uses a fixed aerosol type (coastal aerosol) but permits aerosol concentration to vary at each pixel; this improvement omits a complicated requirement for aerosol model selection based only on satellite data. Second, it shifts the reference band from 670 nm to 754 nm to validate the assumption that the total absorption coefficient at the reference band can be replaced by that of pure water, and thus can avoid the uncorrected estimation of the total absorption coefficient at the reference band in very turbid waters. Third, the N-GWI generates a semi-analytical relationship instead of an empirical one for estimation of the spectral slope of particle backscattering. Our analysis showed that the N-GWI improved the accuracy of atmospheric correction in two very turbid Asian lakes (Lake Kasumigaura, Japan and Lake Dianchi, China), with a normalized mean absolute error (NMAE) of less than 22% for wavelengths longer than 620 nm. However, the N-GWI exhibited poor performance in moderately turbid waters (the NMAE values were larger than 83.6% in the four American coastal waters). The applicability of the N-GWI, which includes both advantages and limitations, was discussed.

  7. "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...

  8. 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.

  9. 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

  10. 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

  11. Inland sea as a unit for environmental history: East Asian inland seas from prehistory to future.

    PubMed

    Lindstrom, Kati; Uchiyama, Junzo

    2012-04-01

    The boundaries of landscape policies often coincide with political or economic boundaries, thus creating a situation where a unit of landscape protection or management reflects more its present political status than its historico-geographical situation, its historical function and formation. At the same time, it is evident that no unit can exist independently of the context that has given birth to it and that environmental protection in isolated units cannot be very effective. The present paper will discuss inland sea as a landscape unit from prehistory to modern days and its implications for future landscape planning, using EastAsian inland sea (Japan Sea and East China Sea) rim as an example. Historically an area of active communication, EastAsian inland sea rim has become a politically very sharply divided area. The authors will bring examples to demonstrate how cultural communication on the inland sea level has influenced the formation of several landscape features that are now targets for local or national landscape protection programs, and how a unified view could benefit the future of landscape policies in the whole region.

  12. 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

  13. 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.

  14. 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'.

  15. Microbial quality of tropical inland waters and effects of rainfall events.

    PubMed

    Santiago-Rodriguez, Tasha M; Tremblay, Raymond L; Toledo-Hernandez, Carlos; Gonzalez-Nieves, Joel E; Ryu, Hodon; Santo Domingo, Jorge W; Toranzos, Gary A

    2012-08-01

    Novel markers of fecal pollution in tropical waters are needed since conventional methods recommended for other geographical regions may not apply. To address this, the prevalence of thermotolerant coliforms, enterococci, coliphages, and enterophages was determined by culture methods across a watershed. Additionally, human-, chicken-, and cattle-specific PCR assays were used to identify potential fecal pollution sources in this watershed. An enterococcus quantitative PCR (qPCR) assay was tested and correlated with culture methods at three sites since water quality guidelines could incorporate this technique as a rapid detection method. Various rainfall events reported before sample collection at three sites were considered in the data analyses. Thermotolerant coliforms, enterococci, coliphages, and enterophages were detected across the watershed. Human-specific Bacteroides bacteria, unlike the cattle- and chicken-specific bacteria, were detected mostly at sites with the corresponding fecal impact. Enterococci were detected by qPCR as well, but positive correlations with the culture method were noted at two sites, suggesting that either technique could be used. However, no positive correlations were noted for an inland lake tested, suggesting that qPCR may not be suitable for all water bodies. Concentrations of thermotolerant coliforms and bacteriophages were consistently lower after rainfall events, pointing to a possible dilution effect. Rainfall positively correlated with enterococci detected by culturing and qPCR, but this was not the case for the inland lake. The toolbox of methods and correlations presented here could be potentially applied to assess the microbial quality of various water types.

  16. 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.

  17. Geochemistry and Mineralogy of Western Australian Salt Lake Sediments: Implications for Meridiani Planum on Mars

    NASA Astrophysics Data System (ADS)

    Ruecker, A.; Schröder, C.; Byrne, J.; Weigold, P.; Behrens, S.; Kappler, A.

    2016-07-01

    Hypersaline lakes are characteristic for Western Australia and display a rare combination of geochemical and mineralogical properties that make these lakes potential analogues for past conditions on Mars. In our study, we focused on the geochemistry and mineralogy of Lake Orr and Lake Whurr. While both lakes are poor in organic carbon (<1%), the sediments' pH values differ and range from 3.8 to 4.8 in Lake Orr and from 5.4 to 6.3 in Lake Whurr sediments. Lake Whurr sediments were dominated by orange and red sediment zones in which the main Fe minerals were identified as hematite, goethite, and tentatively jarosite and pyrite. Lake Orr was dominated by brownish and blackish sediments where the main Fe minerals were goethite and another paramagnetic Fe(III)-phase that could not be identified. Furthermore, a likely secondary Fe(II)-phase was observed in Lake Orr sediments. The mineralogy of these two salt lakes in the sampling area is strongly influenced by events such as flooding, evaporation, and desiccation, processes that explain at least to some extent the observed differences between Lake Orr and Lake Whurr. The iron mineralogy of Lake Whurr sediments and the high salinity make this lake a suitable analogue for Meridiani Planum on Mars, and in particular the tentative identification of pyrite in Lake Whurr sediments has implications for the interpretation of the Fe mineralogy of Meridiani Planum sediments.

  18. Multidate Landsat lake quality monitoring program

    NASA Technical Reports Server (NTRS)

    Fisher, L. T.; Scarpace, F. L.; Thomsen, R. G.

    1979-01-01

    A unified package of files and programs has been developed to automate the multidate Landsat-derived analyses of water quality for about 3000 inland lakes throughout Wisconsin. A master lakes file which stores geographic information on the lakes, a file giving the latitudes and longitudes of control points for scene navigation, and a program to estimate control point locations and produce microfiche character maps for scene navigation are among the files and programs of the system. The use of ground coordinate systems to isolate irregular shaped areas which can be accessed at will appears to provide an economical means of restricting the size of the data set.

  19. Hypersalinity toxicity thresholds for nine California ocean plan toxicity test protocols.

    PubMed

    Voorhees, Jennifer P; Phillips, Bryn M; Anderson, Brian S; Siegler, Katie; Katz, Scott; Jennings, Lydia; Tjeerdema, Ron S; Jensen, Joanna; de la Paz Carpio-Obeso, Maria

    2013-11-01

    Currently, several desalination facilities have been proposed to operate or are actually operating in California. These facilities' use of reverse osmosis (RO) may discharge hypersaline reject brine into the marine environment. The risks, if any, this brine would pose to coastal receiving waters are unknown. To test the toxicity of hypersaline brine in the absence of any additional toxic constituents, we prepared brine and tested it with the seven toxicity test organisms listed in the 2009 California Ocean Plan. The most sensitive protocols were the marine larval development tests, whereas the most tolerant to increased salinities were the euryhaline topsmelt, mysid shrimp, and giant kelp tests. Reject brines from the Monterey Bay Aquarium's RO desalination facility were also tested with three species. The effects of the aquarium's brine effluent on topsmelt, mussels, and giant kelp were consistent with those observed in the salinity tolerance experiments. This information will be used by regulators to establish receiving water limitations for hypersaline discharges.

  20. Biogeography of Nocardiopsis strains from hypersaline environments of Yunnan and Xinjiang Provinces, western China

    PubMed Central

    He, Song-Tao; Zhi, Xiao-Yang; Jiang, Hongchen; Yang, Ling-Ling; Wu, Jin-Yuan; Zhang, Yong-Guang; Hozzein, Wael N.; Li, Wen-Jun

    2015-01-01

    The genus Nocardiopsis is a widespread group within the phylum Actinobacteria and has been isolated from various salty environments worldwide. However, little is known about whether biogeography affects Nocardiopsis distribution in various hypersaline environments. Such information is essential for understanding the ecology of Nocardiopsis. Here we analyzed 16S rRNA, gyrB, rpoB and sodA genes of 78 Nocardiopsis strains isolated from hypersaline environments in Yunnan and Xinjiang Provinces of western China. The obtained Nocardiopsis strains were classified into five operational taxonomic units, each comprising location-specific phylo- and genotypes. Statistical analyses showed that spatial distance and environmental factors substantially influenced Nocardiopsis distribution in hypersaline environments: the former had stronger influence at large spatial scales, whereas the latter was more influential at small spatial scales. PMID:26289784

  1. Ecosystem approach to inland fisheries: research needs and implementation strategies.

    PubMed

    Beard, T Douglas; Arlinghaus, Robert; Cooke, Steven J; McIntyre, Peter B; De Silva, Sena; Bartley, Devin; Cowx, Ian G

    2011-08-23

    Inland fisheries are a vital component in the livelihoods and food security of people throughout the world, as well as contributing huge recreational and economic benefits. These valuable assets are jeopardized by lack of research-based understanding of the impacts of fisheries on inland ecosystems, and similarly the impact of human activities associated with inland waters on fisheries and aquatic biodiversity. To explore this topic, an international workshop was organized in order to examine strategies to incorporate fisheries into ecosystem approaches for management of inland waters. To achieve this goal, a new research agenda is needed that focuses on: quantifying the ecosystem services provided by fresh waters; quantifying the economic, social and nutritional benefits of inland fisheries; improving assessments designed to evaluate fisheries exploitation potential; and examining feedbacks between fisheries, ecosystem productivity and aquatic biodiversity. Accomplishing these objectives will require merging natural and social science approaches to address coupled social-ecological system dynamics.

  2. Ecosystem approach to inland fisheries: Research needs and implementation strategies

    USGS Publications Warehouse

    Beard, T.D.; Arlinghaus, R.; Cooke, S.J.; McIntyre, P.B.; De Silva, S.; Bartley, D.; Cowx, I.G.

    2011-01-01

    Inland fisheries are a vital component in the livelihoods and food security of people throughout the world, as well as contributing huge recreational and economic benefits. These valuable assets are jeopardized by lack of research-based understanding of the impacts of fisheries on inland ecosystems, and similarly the impact of human activities associated with inland waters on fisheries and aquatic biodiversity. To explore this topic, an international workshop was organized in order to examine strategies to incorporate fisheries into ecosystem approaches for management of inland waters. To achieve this goal, a new research agenda is needed that focuses on: quantifying the ecosystem services provided by fresh waters; quantifying the economic, social and nutritional benefits of inland fisheries; improving assessments designed to evaluate fisheries exploitation potential; and examining feedbacks between fisheries, ecosystem productivity and aquatic biodiversity. Accomplishing these objectives will require merging natural and social science approaches to address coupled social-ecological system dynamics. ?? 2010 The Royal Society.

  3. Ecosystem approach to inland fisheries: research needs and implementation strategies

    USGS Publications Warehouse

    Beard, T. Douglas; Arlinghaus, Robert; Cooke, Steven J.; McIntyre, Peter B.; De Silva, Sena; Bartley, Devin M.; Cowx, Ian G.

    2011-01-01

    Inland fisheries are a vital component in the livelihoods and food security of people throughout the world, as well as contributing huge recreational and economic benefits. These valuable assets are jeopardized by lack of research-based understanding of the impacts of fisheries on inland ecosystems, and similarly the impact of human activities associated with inland waters on fisheries and aquatic biodiversity. To explore this topic, an international workshop was organized in order to examine strategies to incorporate fisheries into ecosystem approaches for management of inland waters. To achieve this goal, a new research agenda is needed that focuses on: quantifying the ecosystem services provided by fresh waters; quantifying the economic, social and nutritional benefits of inland fisheries; improving assessments designed to evaluate fisheries exploitation potential; and examining feedbacks between fisheries, ecosystem productivity and aquatic biodiversity. Accomplishing these objectives will require merging natural and social science approaches to address coupled social–ecological system dynamics.

  4. Ecosystem approach to inland fisheries: research needs and implementation strategies

    PubMed Central

    Beard, T. Douglas; Arlinghaus, Robert; Cooke, Steven J.; McIntyre, Peter B.; De Silva, Sena; Bartley, Devin; Cowx, Ian G.

    2011-01-01

    Inland fisheries are a vital component in the livelihoods and food security of people throughout the world, as well as contributing huge recreational and economic benefits. These valuable assets are jeopardized by lack of research-based understanding of the impacts of fisheries on inland ecosystems, and similarly the impact of human activities associated with inland waters on fisheries and aquatic biodiversity. To explore this topic, an international workshop was organized in order to examine strategies to incorporate fisheries into ecosystem approaches for management of inland waters. To achieve this goal, a new research agenda is needed that focuses on: quantifying the ecosystem services provided by fresh waters; quantifying the economic, social and nutritional benefits of inland fisheries; improving assessments designed to evaluate fisheries exploitation potential; and examining feedbacks between fisheries, ecosystem productivity and aquatic biodiversity. Accomplishing these objectives will require merging natural and social science approaches to address coupled social–ecological system dynamics. PMID:21325307

  5. Diel Migrations of Microorganisms within a Benthic, Hypersaline Mat Community

    PubMed Central

    Garcia-Pichel, Ferran; Mechling, Margaret; Castenholz, Richard W.

    1994-01-01

    We studied the diel migrations of several species of microorganisms in a hypersaline, layered microbial mat. The migrations were quantified by repeated coring of the mat with glass capillary tubes. The resulting minicores were microscopically analyzed by using bright-field and epifluorescence (visible and infrared) microscopy to determine depths of coherent layers and were later dissected to determine direct microscopic counts of microorganisms. Microelectrode measurements of oxygen concentration, fiber optic microprobe measurements of light penetration within the mat, and incident irradiance measurements accompanied the minicore sampling. In addition, pigment content, photosynthesis and irradiance responses, the capacity for anoxygenic photosynthesis, and gliding speeds were determined for the migrating cyanobacteria. Heavily pigmented Oscillatoria sp. and Spirulina cf. subsalsa migrated downward into the mat during the early morning and remained deep until dusk, when upward migration occurred. The mean depth of the migration (not more than 0.4 to 0.5 mm) was directly correlated with the incident irradiance over the mat surface. We estimated that light intensity at the upper boundary of the migrating cyanobacteria was attenuated to such an extent that photoinhibition was effectively avoided but that intensities which saturated photosynthesis were maintained through most of the daylight hours. Light was a cue of paramount importance in triggering and modulating the migration of the cyanobacteria, even though the migrating phenomenon could not be explained solely in terms of a light response. We failed to detect diel migration patterns for other cyanobacterial species and filamentous anoxyphotobacteria. The sulfide-oxidizing bacterium Beggiatoa sp. migrated as a band that followed low oxygen concentrations within the mat during daylight hours. During the nighttime, part of this population migrated toward the mat surface, but a significant proportion remained deep

  6. Chemical modeling for precipitation from hypersaline hydrofracturing brines.

    PubMed

    Zermeno-Motante, Maria I; Nieto-Delgado, Cesar; Cannon, Fred S; Cash, Colin C; Wunz, Christopher C

    2016-10-15

    Hypersaline hydrofracturing brines host very high salt concentrations, as high as 120,000-330,000 mg/L total dissolved solids (TDS), corresponding to ionic strengths of 2.1-5.7 mol/kg. This is 4-10 times higher than for ocean water. At such high ionic strengths, the conventional equations for computing activity coefficients no longer apply; and the complex ion-interactive Pitzer model must be invoked. The authors herein have used the Pitzer-based PHREEQC computer program to compute the appropriate activity coefficients when forming such precipitates as BaSO4, CaSO4, MgSO4, SrSO4, CaCO3, SrCO3, and BaCO3 in hydrofracturing waters. The divalent cation activity coefficients (γM) were computed in the 0.1 to 0.2 range at 2.1 mol/kg ionic strength, then by 5.7 mol/kg ionic strength, they rose to 0.2 for Ba(2+), 0.6 for Sr(2+), 0.8 for Ca(2+), and 2.1 for Mg(2+). Concurrently, the [Formula: see text] was 0.02-0.03; and [Formula: see text] was 0.01-0.02. While employing these Pitzer-derived activity coefficients, the authors then used the PHREEQC model to characterize precipitation of several of these sulfates and carbonates from actual hydrofracturing waters. Modeled precipitation matched quite well with actual laboratory experiments and full-scale operations. Also, the authors found that SrSO4 effectively co-precipitated radium from hydrofracturing brines, as discerned when monitoring (228)Ra and other beta-emitting species via liquid scintillation; and also when monitoring gamma emissions from (226)Ra.

  7. Chemical modeling for precipitation from hypersaline hydrofracturing brines.

    PubMed

    Zermeno-Motante, Maria I; Nieto-Delgado, Cesar; Cannon, Fred S; Cash, Colin C; Wunz, Christopher C

    2016-10-15

    Hypersaline hydrofracturing brines host very high salt concentrations, as high as 120,000-330,000 mg/L total dissolved solids (TDS), corresponding to ionic strengths of 2.1-5.7 mol/kg. This is 4-10 times higher than for ocean water. At such high ionic strengths, the conventional equations for computing activity coefficients no longer apply; and the complex ion-interactive Pitzer model must be invoked. The authors herein have used the Pitzer-based PHREEQC computer program to compute the appropriate activity coefficients when forming such precipitates as BaSO4, CaSO4, MgSO4, SrSO4, CaCO3, SrCO3, and BaCO3 in hydrofracturing waters. The divalent cation activity coefficients (γM) were computed in the 0.1 to 0.2 range at 2.1 mol/kg ionic strength, then by 5.7 mol/kg ionic strength, they rose to 0.2 for Ba(2+), 0.6 for Sr(2+), 0.8 for Ca(2+), and 2.1 for Mg(2+). Concurrently, the [Formula: see text] was 0.02-0.03; and [Formula: see text] was 0.01-0.02. While employing these Pitzer-derived activity coefficients, the authors then used the PHREEQC model to characterize precipitation of several of these sulfates and carbonates from actual hydrofracturing waters. Modeled precipitation matched quite well with actual laboratory experiments and full-scale operations. Also, the authors found that SrSO4 effectively co-precipitated radium from hydrofracturing brines, as discerned when monitoring (228)Ra and other beta-emitting species via liquid scintillation; and also when monitoring gamma emissions from (226)Ra. PMID:27470293

  8. Diel Metagenomics and Metatranscriptomics of Elkhorn Slough Hypersaline Microbial Mat

    NASA Astrophysics Data System (ADS)

    Lee, J.; Detweiler, A. M.; Everroad, R. C.; Bebout, L. E.; Weber, P. K.; Pett-Ridge, J.; Bebout, B.

    2014-12-01

    To understand the variation in gene expression associated with the daytime oxygenic phototrophic and nighttime fermentation regimes seen in hypersaline microbial mats, a contiguous mat piece was subjected to sampling at regular intervals over a 24-hour diel period. Additionally, to understand the impact of sulfate reduction on biohydrogen consumption, molybdate was added to a parallel experiment in the same run. 4 metagenome and 12 metatranscriptome Illumina HiSeq lanes were completed over day / night, and control / molybdate experiments. Preliminary comparative examination of noon and midnight metatranscriptomic samples mapped using bowtie2 to reference genomes has revealed several notable results about the dominant mat-building cyanobacterium Microcoleus chthonoplastes PCC 7420. Dominant cyanobacterium M. chthonoplastes PCC 7420 shows expression in several pathways for nitrogen scavenging, including nitrogen fixation. Reads mapped to M. chthonoplastes PCC 7420 shows expression of two starch storage and utilization pathways, one as a starch-trehalose-maltose-glucose pathway, another through UDP-glucose-cellulose-β-1,4 glucan-glucose pathway. The overall trend of gene expression was primarily light driven up-regulation followed by down-regulation in dark, while much of the remaining expression profile appears to be constitutive. Co-assembly of quality-controlled reads from 4 metagenomes was performed using Ray Meta with progressively smaller K-mer sizes, with bins identified and filtered using principal component analysis of coverages from all libraries and a %GC filter, followed by reassembly of the remaining co-assembly reads and binned reads. Despite having relatively similar abundance profiles in each metagenome, this binning approach was able to distinctly resolve bins from dominant taxa, but also sulfate reducing bacteria that are desired for understanding molybdate inhibition. Bins generated from this iterative assembly process will be used for downstream

  9. Condition-dependent migratory behaviour of endangered Atlantic salmon smolts moving through an inland sea.

    PubMed

    Crossin, Glenn T; Hatcher, Bruce G; Denny, Shelley; Whoriskey, Kim; Orr, Michael; Penney, Alicia; Whoriskey, Frederick G

    2016-01-01

    The Bras d'Or Lake watershed of Cape Breton Island, Nova Scotia, Canada is a unique inland sea ecosystem, UNESCO Biosphere Reserve and home to a group of regionally distinct Atlantic salmon (Salmo salar) populations. Recent population decreases in this region have raised concern about their long-term persistence. We used acoustic telemetry to track the migrations of juvenile salmon (smolts) from the Middle River into the Bras d'Or Lake and, subsequently, into the Atlantic Ocean. Roughly half of the tagged smolts transited the Bras d'Or Lakes to the Atlantic Ocean, using a migration route that took them through the Gulf of St Lawrence's northern exit at the Strait of Belle Isle (∼650 km from the home river) towards feeding areas in the Labrador Sea and Greenland. However, a significant fraction spent >70 days in the Lakes, suggesting that this population has an alternative resident form, in which smolts limit their migrations within the Bras d'Or. Smolts in good relative condition (as determined from length-to-mass relationships) tended to be residents, whereas fish in poorer condition were ocean migrants. We also found a covarying effect of river temperature that helped to predict residence vs. ocean migration. We discuss these results relative to their bioenergetic implications and provide suggestions for future studies aimed at the conservation of declining salmon populations in Canada. PMID:27293765

  10. Condition-dependent migratory behaviour of endangered Atlantic salmon smolts moving through an inland sea

    PubMed Central

    Crossin, Glenn T.; Hatcher, Bruce G.; Denny, Shelley; Whoriskey, Kim; Orr, Michael; Penney, Alicia; Whoriskey, Frederick G.

    2016-01-01

    The Bras d’Or Lake watershed of Cape Breton Island, Nova Scotia, Canada is a unique inland sea ecosystem, UNESCO Biosphere Reserve and home to a group of regionally distinct Atlantic salmon (Salmo salar) populations. Recent population decreases in this region have raised concern about their long-term persistence. We used acoustic telemetry to track the migrations of juvenile salmon (smolts) from the Middle River into the Bras d’Or Lake and, subsequently, into the Atlantic Ocean. Roughly half of the tagged smolts transited the Bras d’Or Lakes to the Atlantic Ocean, using a migration route that took them through the Gulf of St Lawrence’s northern exit at the Strait of Belle Isle (∼650 km from the home river) towards feeding areas in the Labrador Sea and Greenland. However, a significant fraction spent >70 days in the Lakes, suggesting that this population has an alternative resident form, in which smolts limit their migrations within the Bras d’Or. Smolts in good relative condition (as determined from length-to-mass relationships) tended to be residents, whereas fish in poorer condition were ocean migrants. We also found a covarying effect of river temperature that helped to predict residence vs. ocean migration. We discuss these results relative to their bioenergetic implications and provide suggestions for future studies aimed at the conservation of declining salmon populations in Canada. PMID:27293765

  11. Preservation of ancestral Cretaceous microflora recovered from a hypersaline oil reservoir

    PubMed Central

    Gales, Grégoire; Tsesmetzis, Nicolas; Neria, Isabel; Alazard, Didier; Coulon, Stéphanie; Lomans, Bart P.; Morin, Dominique; Ollivier, Bernard; Borgomano, Jean; Joulian, Catherine

    2016-01-01

    Microbiology of a hypersaline oil reservoir located in Central Africa was investigated with molecular and culture methods applied to preserved core samples. Here we show that the community structure was partially acquired during sedimentation, as many prokaryotic 16S rRNA gene sequences retrieved from the extracted DNA are phylogenetically related to actual Archaea inhabiting surface evaporitic environments, similar to the Cretaceous sediment paleoenvironment. Results are discussed in term of microorganisms and/or DNA preservation in such hypersaline and Mg-rich solutions. High salt concentrations together with anaerobic conditions could have preserved microbial/molecular diversity originating from the ancient sediment basin wherein organic matter was deposited. PMID:26965360

  12. Preservation of ancestral Cretaceous microflora recovered from a hypersaline oil reservoir

    NASA Astrophysics Data System (ADS)

    Gales, Grégoire; Tsesmetzis, Nicolas; Neria, Isabel; Alazard, Didier; Coulon, Stéphanie; Lomans, Bart P.; Morin, Dominique; Ollivier, Bernard; Borgomano, Jean; Joulian, Catherine

    2016-03-01

    Microbiology of a hypersaline oil reservoir located in Central Africa was investigated with molecular and culture methods applied to preserved core samples. Here we show that the community structure was partially acquired during sedimentation, as many prokaryotic 16S rRNA gene sequences retrieved from the extracted DNA are phylogenetically related to actual Archaea inhabiting surface evaporitic environments, similar to the Cretaceous sediment paleoenvironment. Results are discussed in term of microorganisms and/or DNA preservation in such hypersaline and Mg-rich solutions. High salt concentrations together with anaerobic conditions could have preserved microbial/molecular diversity originating from the ancient sediment basin wherein organic matter was deposited.

  13. Towards the water level fluctuations of Lake Nam Co with a lumped watershed-lake model

    NASA Astrophysics Data System (ADS)

    Li, Binquan; Chen, Li; Liang, Zhongmin; Yu, Zhongbo

    2015-04-01

    Hydrologic cycles of most inland lake watersheds on the Tibetan Plateau are not closely monitored due to lack of observation abilities in the harsh environment. Understanding the hydrologic processes of lake watersheds in the Tibetan Plateau 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 simple and plausible hydrologic models. In this study, water level fluctuations of an inland saline lake in the central Tibetan Plateau, Nam Co, were investigated using a lumped watershed-lake model. This terminal lake is fed by both precipitation and glacier melt water from west slopes of Nyainqentanglha Ranges. The degree-day factor method was introduced to improve the model applicability in the glacier-covered basins. The model simulated the hydrologic processes as well as lake water budget of the Nam Co watershed. Remote sensing images (Landsat MSS, TM and ETM) from 1972 to 2008 were used to identify the boundaries of glacier and lake. Multi-source climate data (e.g., ground point observation, 0.25o gridded APHRODITE and TRMM 3B42 v7) were used to drive the hydrologic model at a monthly time step. It was found that both precipitation and air temperature experienced increasing trends with rates of 2.2 mm/year and 0.04 oC/year, respectively, for the period of 1963-2012. As a response to climate change, in the study basin, glaciers decreased by 51 km2 (-23%) while lakes expanded by 98 km2 (+5%) from 1972 to 2007. Results also showed that, during the period of 1961-2013, precipitation on lake, surface and subsurface runoff productions contributed 33%, 39% and 28%, respectively, to the total water mass gain of Lake Nam Co. As for its water sinks, lake water evaporation and groundwater outflow contributions were 63% and 23%, respectively. Consequently, a 14% of incoming water remained in the lake, producing an increase of the

  14. Water Quality Monitoring of Inland Waters using Meris data

    NASA Astrophysics Data System (ADS)

    Potes, M.; Costa, M. J.; Salgado, R.; Le Moigne, P.

    2012-04-01

    The successful launch of ENVISAT in March 2002 has given a great opportunity to understand the optical changes of water surfaces, including inland waters such as lakes and reservoirs, through the use of the Medium Resolution Imaging Spectrometer (MERIS). The potential of this instrument to describe variations of optically active substances has been examined in the Alqueva reservoir, located in the south of Portugal, where satellite spectral radiances are corrected for the atmospheric effects to obtain the surface spectral reflectance. In order to validate this spectral reflectance, several field campaigns were carried out, with a portable spectroradiometer, during the satellite overpass. The retrieved lake surface spectral reflectance was combined with limnological laboratory data and with the resulting algorithms, spatial maps of biological quantities and turbidity were obtained, allowing for the monitoring of these water quality indicators. In the framework of the recent THAUMEX 2011 field campaign performed in Thau lagoon (southeast of France) in-water radiation, surface irradiation and reflectance measurements were taken with a portable spectrometer in order to test the methodology described above. At the same time, water samples were collected for laboratory analysis. The two cases present different results related to the geographic position, water composition, environment, resources exploration, etc. Acknowledgements This work is financed through FCT grant SFRH/BD/45577/2008 and through FEDER (Programa Operacional Factores de Competitividade - COMPETE) and National funding through FCT - Fundação para a Ciência e a Tecnologia in the framework of projects FCOMP-01-0124-FEDER-007122 (PTDC / CTE-ATM / 65307 / 2006) and FCOMP-01-0124-FEDER-009303 (PTDC/CTE-ATM/102142/2008). Image data has been provided by ESA in the frame of ENVISAT projects AOPT-2423 and AOPT-2357. We thank AERONET investigators for their effort in establishing and maintaining Évora AERONET

  15. Productivity Estimation of Hypersaline Microbial Mat Communities - Diurnal Cycles of Dissolved Oxygen

    NASA Astrophysics Data System (ADS)

    Less, G.; Cohen, Y.; Luz, B.; Lazar, B.

    2002-05-01

    Hypersaline microbial mat communities (MMC) are the modern equivalents of the Archean stromatolities, the first photosynthetic organisms on Earth. An estimate of their oxygen production rate is important to the understanding of oxygen evolution on Earth ca. 2 b.y.b.p. Here we use the diurnal cycle of dissolved oxygen, O2/Ar ratio and the isotopic composition of dissolved oxygen to calculate net and gross primary productivity of MMC growing in a large scale (80 m2) experimental pan. The pan is inoculated with MMC taken from the Solar Lake, Sinai, Egypt and filled with 90\\permil evaporated Red Sea water brine up to a depth of ca. 0.25 m. It is equipped with computerized flow through system that is programmed to pump pan water at selected time intervals into a sampling cell fitted with dissolved oxygen, pH, conductivity and temperature sensors connected to a datalogger. Manual brine samples were taken for calibrating the sensors, mass spectrometric analyses and for measurements of additional relevant parameters. Dissolved oxygen concentrations fluctuate during the diurnal cycle being highly supersaturated except for the end of the night. The O2 curve varies seasonally and has a typical "shark fin" shape due to the MMC metabolic response to the shape of the diurnal light curve. The dissolved oxygen data were fitted to a smooth curve that its time derivative (dO2 /dt) is defined as: Z dO2 /dt=GP-R-k(O2(meas)- O2(sat)) where z is the depth (m); GP and R are the MMC gross production and respiration (mol m-2 d-1), respectively; k is the gas exchange coefficient (m d-1); O2(meas) and O2(sat) (mol L-1) are the measured and equilibrium dissolved oxygen concentrations, respectively. The high resolution sampling of the automated system produces O2 curves that enable the calculation of smooth and reliable time derivatives. The calculations yield net production values that vary between 1,000 10-6 to -100 10-6 mol O2 m-2 h-1 and day respiration rates between 60 10-6 to 30 10

  16. Hypersaline Subsurface Microbial Communities from the Dead Sea Viewed from Their Metagenomes.

    NASA Astrophysics Data System (ADS)

    Thomas, C.; Ionescu, D.; Ariztegui, D.

    2014-12-01

    The Dead Sea Deep Drilling Project (DSDDP) is an international research initiative aiming to reconstruct the paleoenvironmental and paleoseismic history of the Dead Sea Basin (DSB) in the Levantine region. Within this framework, analysis of microbial communities intend to qualify the extent of life in this extreme environment, the factors allowing its development and their contribution to the sedimentary and geochemical record. The extreme chemistry of the Dead Sea prevents the use of common in situ imaging techniques leaving little information on the general activity of the subsurface biosphere. Cloning and metagenomic techniques have however been implemented at different levels of a 457 m deep core. Results suggest a differential development or survival of the microbial community along the sedimentary column. Reasons for such distribution remain unclear but cannot only be imparted to salinity. Poorly known communities (e.g. Candidate Divisions MSBL1 and KB1) with strong potential for adaptations to anoxic hypersaline environments are recovered in some intervals. Halobacteria classes generally dominate the assemblages. Metagenomic data allowed characterizing their presence in two evaporitic facies of the core (aragonite at 2.7 m and gypsum at 90.6 m below lake floor), where they exhibit both salt-in and salt-out strategies to cope with the high salinities of the Dead Sea. Metabolisms are also adapted to the high heavy metal concentrations and low nutrient availability in the sediment. Although more work is needed in order to infer the impact of these microorganisms on the sediment and element cycles, indices of methanogenesis, fermentation and sulfate reducing activity imply influence on the carbon and sulfur cycle of the Dead Sea subsurface. This is highlighted by traces of microbial degradation of organic matter viewed under SEM, and by the formation of euhedral Fe-S mineralizations as a result of reduction of sulfur. Overall, this work calls for the importance

  17. 15 CFR 923.31 - Inland boundary.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... quantity of seawater, as defined by and uniformly applied by the State; (4) Salt marshes and wetlands—Areas subject to regular inundation of tidal salt (or Great Lakes) waters which contain marsh flora typical of... subject to coastal storm surge, and areas containing vegetation that is salt tolerant and survives...

  18. Environmental determinants of cholera outbreaks in inland Africa: a systematic review of main transmission foci and propagation routes.

    PubMed

    Rebaudet, Stanislas; Sudre, Bertrand; Faucher, Benoît; Piarroux, Renaud

    2013-11-01

    Cholera is generally regarded as the prototypical waterborne and environmental disease. In Africa, available studies are scarce, and the relevance of this disease paradigm is questionable. Cholera outbreaks have been repeatedly reported far from the coasts: from 2009 through 2011, three-quarters of all cholera cases in Africa occurred in inland regions. Such outbreaks are either influenced by rainfall and subsequent floods or by drought- and water-induced stress. Their concurrence with global climatic events has also been observed. In lakes and rivers, aquatic reservoirs of Vibrio cholerae have been evocated. However, the role of these reservoirs in cholera epidemiology has not been established. Starting from inland cholera-endemic areas, epidemics burst and spread to various environments, including crowded slums and refugee camps. Human displacements constitute a major determinant of this spread. Further studies are urgently needed to better understand these complex dynamics, improve water and sanitation efforts, and eliminate cholera from Africa.

  19. Lake Life.

    ERIC Educational Resources Information Center

    Ohrn, Deborah Gore, Ed.

    1993-01-01

    This quarterly publication of the State Historical Society of Iowa features articles and activities for elementary school students. This summer issue focuses on the topic of lake life. The issue includes the following features: (1) "Where the Lakes Are Map"; (2) "Letter from the Lake"; (3) "Lake People"; (4) "Spirit Lake"; (5) "Lake Manawa"; (6)…

  20. Contemporary microbes in hypersaline springs that contain fossil carbon

    NASA Astrophysics Data System (ADS)

    Ziolkowski, L. A.; Mykytczuk, N. C.; Whyte, L.; Slater, G. F.

    2011-12-01

    On Axel Heiberg Island, near 80 oN in the Canadian Arctic, perennial hypersaline springs provide a unique environment for cold-active microbes. The neutral pH Gypsum Hill springs originate in a gypsum diaper and flow through 600 m of continuous permafrost before reaching the surface at ~6 oC, 7.5 % NaCl, low dissolved inorganic carbon and rich in both sulfate and sulfide (Pollard et al., 2009). In the first part of the year, when ambient temperatures dip as low as -40 oC, filamentous streamers are abundant under the snow covered run-off channels. These microbial assemblages are not present during the summer, when the snow cover has melted. Culture- and molecular-based analyses of the 16S rRNA gene indicated that the streamers are dominated by a chemolithoautotrophic sulfur-oxidizing Thiomicrospira species and under in situ conditions the streamers oxidized sulfide and thiosulfate and also fixed CO2 (Perreault et al., 2008). We characterized the isotopic composition (13C and 14C) of the microbial community biomarkers as phospholipid fatty acid (PLFA) and glycolipid fatty acid (GLFA) methyl esters. These components represent the cell membranes of the viable microbial community, which are quickly hydrolyzed after cell death and provide insight into the carbon cycling of the organisms. Even though isotopic measurements of the bulk biomass indicate carbon and nitrogen limitation within the system, the streamers are rich in biomass with greater than 109 cells/g. While the PLFA and GLFA profiles were similar, indicating a predominantly gram-negative bacteria community, the 13C composition of these two lipid types was different. The PLFA δ13C indicated a dominant autotrophic signal, while the δ13C of the GLFA had a more heterotrophic signal. While the streamers grow yearly, their 14C age based on the lipid results was 6400 years, indicating utilization of a carbon source that is 14C depleted. We hypothesize that these microbes are using 14C depleted dissolved inorganic

  1. Dynamics of Molecular Hydrogen in Hypersaline Microbial Mars

    NASA Technical Reports Server (NTRS)

    Hoehler, Tori M.; Bebout, Brad M.; Visscher, Pieter T.; DesMarais, David J.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Early Earth microbial communities that centered around the anaerobic decomposition of organic molecular hydrogen as a carrier of electrons, regulator of energy metabolism, and facilitator of syntroph'c microbial interactions. The advent of oxygenic photosynthetic organisms added a highly dynamic and potentially dominant term to the hydrogen economy of these communities. We have examined the daily variations of hydrogen concentrations in cyanobacteria-dominated microbial mats from hypersaline ponds in Baja California Sur, Mexico. These mats bring together phototrophic and anaerobic bacteria (along with virtually all other trophic groups) in a spatially ordered and chemically dynamic matrix that provides a good analog for early Earth microbial ecosystems. Hydrogen concentrations in the photic zone of the mat can be three orders of magnitude or more higher than in the photic zone, which are, in turn, an order of magnitude higher than in the unconsolidated sediments underlying the mat community. Within the photic zone, hydrogen concentrations can fluctuate dramatically during the diel (24 hour day-night) cycle, ranging from less than 0.001% during the day to nearly 10% at night. The resultant nighttime flux of hydrogen from the mat to the environment was up to 17% of the daytime oxygen flux. The daily pattern observed is highly dependent on cyanobacterial species composition within the mat, with Lyngbya-dominated systems having a much greater dynamic range than those dominated by Microcoleus; this may relate largely to differing degrees of nitrogen-fixing and fermentative activity in the two mats. The greatest H2 concentrations and fluxes were observed in the absence of oxygen, suggesting an important potential feedback control in the context of the evolution of atmospheric composition. The impact of adding this highly dynamic photosynthetic term to the hydrogen economy of early microbial ecosystems must have been substantial. From an evolutionary standpoint, the H2

  2. Diversity of bacteria and archaea in hypersaline sediment from Death Valley National Park, California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to phylogenetically analyze microorganisms from the domains Bacteria and Archaea in hypersaline sediment from Death Valley National Park. Using domain-specific primers, a region of the 16S rRNA gene was amplified using PCR, and the product was subsequently used to cr...

  3. Methane and carbon dioxide emissions from inland waters in India - implications for large scale greenhouse gas balances.

    PubMed

    Panneer Selvam, Balathandayuthabani; Natchimuthu, Sivakiruthika; Arunachalam, Lakshmanan; Bastviken, David

    2014-11-01

    Inland waters were recently recognized to be important sources of methane (CH4 ) and carbon dioxide (CO2 ) to the atmosphere, and including inland water emissions in large scale greenhouse gas (GHG) budgets may potentially offset the estimated carbon sink in many areas. However, the lack of GHG flux measurements and well-defined inland water areas for extrapolation, make the magnitude of the potential offset unclear. This study presents coordinated flux measurements of CH4 and CO2 in multiple lakes, ponds, rivers, open wells, reservoirs, springs, and canals in India. All these inland water types, representative of common aquatic ecosystems in India, emitted substantial amounts of CH4 and a major fraction also emitted CO2 . The total CH4 flux (including ebullition and diffusion) from all the 45 systems ranged from 0.01 to 52.1 mmol m(-2)  d(-1) , with a mean of 7.8 ± 12.7 (mean ± 1 SD) mmol m(-2)  d(-1) . The mean surface water CH4 concentration was 3.8 ± 14.5 μm (range 0.03-92.1 μm). The CO2 fluxes ranged from -28.2 to 262.4 mmol m(-2)  d(-1) and the mean flux was 51.9 ± 71.1 mmol m(-2)  d(-1) . The mean partial pressure of CO2 was 2927 ± 3269 μatm (range: 400-11 467 μatm). Conservative extrapolation to whole India, considering the specific area of the different water types studied, yielded average emissions of 2.1 Tg CH4  yr(-1) and 22.0 Tg CO2  yr(-1) from India's inland waters. When expressed as CO2 equivalents, this amounts to 75 Tg CO2 equivalents yr(-1) (53-98 Tg CO2 equivalents yr(-1) ; ± 1 SD), with CH4 contributing 71%. Hence, average inland water GHG emissions, which were not previously considered, correspond to 42% (30-55%) of the estimated land carbon sink of India. Thereby this study illustrates the importance of considering inland water GHG exchange in large scale assessments.

  4. Rotifers from selected inland saline waters in the Chihuahuan Desert of México

    PubMed Central

    Walsh, Elizabeth J; Schröder, Thomas; Wallace, Robert L; Ríos-Arana, Judith V; Rico-Martínez, Roberto

    2008-01-01

    Background In spite of considerable efforts over past decades we still know relatively little regarding the biogeography of rotifers of inland waters in México. To help rectify this we undertook an extensive survey of the rotifer fauna of 48 water bodies in the Chihuahuan Desert of México. Results Of the sites surveyed, 21 had salinities ≥ 2000 μS cm-1 and in these we found 57 species of monogonont rotifers and several bdelloids. Species richness in the saline sites varied widely, with a range in species richness of 1 to 27 and a mean (± 1SD) = 8.8 (± 6.2). Collectively all sites possess relatively high percent single- and doubletons, 33.3 and 21.7%, respectively. Simpson's Asymmetric Index indicated that similarity in rotifer species composition varied widely among a set of 10 sites. These were selected because they were sampled more frequently or represent unusual habitats. These SAI values ranged from 0.00 (complete dissimilarity) to 1.00 (complete similarity). The Jaccard Index varied between 0.00 and 0.35. This observation probably reflects similarities and differences in water chemistry among these sites. Inland saline systems differed in their chemical composition by region. Conductivity was related to hardness and alkalinity. In addition, hardness was positively associated with chloride and sulfate. RDA showed that several species were positively associated with chloride concentration. Other factors that were significantly associated with rotifer species included the presence of macrophytes, nitrate content, oxygen concentration, TDS, latitude and whether the habitat was a large lake or reservoir. Conclusion This study illustrates the diversity of the rotiferan fauna of inland saline systems and the uniqueness among waterbodies. Conservation of these systems is needed to preserve these unique sources of biodiversity that include rotifers and the other endemic species found in association with them. PMID:18533042

  5. VIEW INLAND (MAUKA) FROM BEACH ROAD. NOTE THE APPROXIMATE 46' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW INLAND (MAUKA) FROM BEACH ROAD. NOTE THE APPROXIMATE 46' DISTANCE BETWEEN RESIDENCES 26 AND 28 WORCHESTER AVENUE. VIEW FACING NORTHEAST. - Hickam Field, Fort Kamehameha Historic Housing, Along Worchester Avenue & Hope Street, Honolulu, Honolulu County, HI

  6. Proceedings of GLaSS: Global Lakes Sentinel Services

    NASA Astrophysics Data System (ADS)

    Peters, Steef; Hommersom, Annelies; Alikas, Krista; Heege, Thomas; Schenk, Karin; Ruescas, Ana; Eleveld, Marieke; Giardino, Claudia; Koponen, Sampsa; Kallio, Kari; Philipson, Petra

    2015-12-01

    Global Lakes Sentinel Services (GLaSS) is developing a prototype Sentinel service infrastructure to ingest and process Sentinel-2 and Sentinel-3 data into validated ecological water quality parameters for lakes, plus training material. GLaSS is an EU-funded R&D project within the Copernicus framework. The project is well on its way to reach its goals. Some results on comparisons on atmospheric correction methods for inland waters are presented here.

  7. Combined stable isotope, proteomic, metabolomics, and spatial specific analysis to track carbon flow through a hypersaline phototrophic microbial mat

    NASA Astrophysics Data System (ADS)

    Moran, J.; Cory, A.; Riha, K. M.; Huang, E. L.; Gritsenko, M. A.; Kim, Y. M.; Metz, T. O.; Lipton, M. S.

    2014-12-01

    Tracking labeled substrates through microbial mat systems can help elucidate carbon dynamics, species interactions, and niche partitioning, but the inherent microbial complexity of these systems makes them difficult to probe with single analytical techniques. Here we use a combination of different tools to track three labeled substrates through a benthic phototrophic mat from Hot Lake. Hot Lake is a hypersaline, meromictic lake located in an endorheic basin in north-central Washington which, despite extreme salinity and seasonal water temperatures (> 55 ˚C), hosts dense, phototrophic benthic microbial mats. Cyanobacteria are the dominant CO2-fixing organisms in the system 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. We performed ex situ incubations over a complete diel cycle with 13C labeled bicarbonate, acetate, and glucose. Traditional elemental analysis IRMS provided an estimate of bulk label uptake to total biomass and showed that both bicarbonate and acetate were incorporated only during daylight while glucose uptake was nearly constant through the cycle. Spatially resolved isotope analysis using laser ablation IRMS showed distinctive patterns between the different substrates with bicarbonate having highest uptake in the top third of the mat, acetate uptake focused near the mat's center, and glucose showing similar uptake at all mat depths. Proteomic analysis showed a longer lag in substrate conversion to protein than to biomass and a distinct spike in the number of labeled peptides in the bicarbonate incubation near the end of the diel cycle. Proteomic analysis confirmed that photosynthetic organisms showed the highest rates of label conversion to protein but heterotrophic organisms also incorporated label into their peptides. Metabolomic analysis demonstrated the high conversion of organic substrates

  8. Methanogenesis at extremely haloalkaline conditions in the soda lakes of Kulunda Steppe (Altai, Russia).

    PubMed

    Sorokin, Dimitry Y; Abbas, Ben; Geleijnse, Mitchell; Pimenov, Nikolai V; Sukhacheva, Marina V; van Loosdrecht, Mark C M

    2015-04-01

    Microbial methanogenesis at extreme conditions of saline alkaline soda lakes has, so far, been poorly investigated. Despite the obvious domination of sulfidogenesis as the therminal anaerobic process in the hypersaline soda lakes of Kulunda Steppe (Altai, southwestern Siberia), high concentrations of methane were detected in the anaerobic sediments. Potential activity measurements with different substrates gave results significantly deviating from what is commonly found in hypersaline habitats with neutral pH. In particular, not only a non-competitive methylotrophic pathway was active, but also lithotrophic and, in some cases, even acetate-dependent methanogenesis was found to be present in hypersaline soda lake sediments. All three pathways were functioning exclusively within the alkaline pH range between 8 and 10.5, while the salt concentration was the key factor influencing the activity. Methylotrophic and, to a lesser extent, lithotrophic methanogenesis were active up to soda-saturating conditions (4 M total Na(+)). Acetate-dependent methanogenesis was observed at salinities below 3 M total Na(+). Detection of methanogens in sediments using the mcrA gene as a functional marker demonstrated domination of methylotrophic genera Methanolobus and Methanosalsum and lithotrophic Methanocalculus. In a few cases, acetoclastic Methanosaeta was detected, as well as two deep lineage methanogens. Cultivation results corresponded well to the mcrA-based observations. Enrichments for natronophilic methylotrophic methanogens resulted in isolation of Methanolobus strains at moderate salinity, while at salt concentrations above 2 M Na(+) a novel member of the genus Methanosalsum was dominating. Enrichments with H2 or formate invariably resulted in domination of close relatives of Methanocalculus natronophilus. Enrichments with acetate at low salt concentration yielded two acetoclastic alkaliphilic Methanosaeta cultures, while at salinity above 1 M Na(+) syntrophic associations

  9. Methanogenesis at extremely haloalkaline conditions in the soda lakes of Kulunda Steppe (Altai, Russia).

    PubMed

    Sorokin, Dimitry Y; Abbas, Ben; Geleijnse, Mitchell; Pimenov, Nikolai V; Sukhacheva, Marina V; van Loosdrecht, Mark C M

    2015-04-01

    Microbial methanogenesis at extreme conditions of saline alkaline soda lakes has, so far, been poorly investigated. Despite the obvious domination of sulfidogenesis as the therminal anaerobic process in the hypersaline soda lakes of Kulunda Steppe (Altai, southwestern Siberia), high concentrations of methane were detected in the anaerobic sediments. Potential activity measurements with different substrates gave results significantly deviating from what is commonly found in hypersaline habitats with neutral pH. In particular, not only a non-competitive methylotrophic pathway was active, but also lithotrophic and, in some cases, even acetate-dependent methanogenesis was found to be present in hypersaline soda lake sediments. All three pathways were functioning exclusively within the alkaline pH range between 8 and 10.5, while the salt concentration was the key factor influencing the activity. Methylotrophic and, to a lesser extent, lithotrophic methanogenesis were active up to soda-saturating conditions (4 M total Na(+)). Acetate-dependent methanogenesis was observed at salinities below 3 M total Na(+). Detection of methanogens in sediments using the mcrA gene as a functional marker demonstrated domination of methylotrophic genera Methanolobus and Methanosalsum and lithotrophic Methanocalculus. In a few cases, acetoclastic Methanosaeta was detected, as well as two deep lineage methanogens. Cultivation results corresponded well to the mcrA-based observations. Enrichments for natronophilic methylotrophic methanogens resulted in isolation of Methanolobus strains at moderate salinity, while at salt concentrations above 2 M Na(+) a novel member of the genus Methanosalsum was dominating. Enrichments with H2 or formate invariably resulted in domination of close relatives of Methanocalculus natronophilus. Enrichments with acetate at low salt concentration yielded two acetoclastic alkaliphilic Methanosaeta cultures, while at salinity above 1 M Na(+) syntrophic associations

  10. Ancient lakes as evolutionary reservoirs: evidence from the thalassoid gastropods of Lake Tanganyika.

    PubMed Central

    Wilson, Anthony B.; Glaubrecht, Matthias; Meyer, Axel

    2004-01-01

    Ancient lakes are often collectively viewed as evolutionary hot spots of diversification. East Africa's Lake Tanganyika has long been the subject of scientific interest owing to dramatic levels of endemism in species as diverse as cichlid fishes, paludomid gastropods, decapod and ostracod crustaceans and poriferans. It is the largest and deepest of the African rift lakes, and its endemic fauna has been presented with a stable inland environment for over 10 Myr, offering unique opportunities for within-lake diversification. Although astonishing diversification has been documented in the endemic cichlid fauna of the lake, similar patterns of rapid diversification have long been assumed for other groups. In contrast to this hypothesis of rapid speciation, we show here that there has been no acceleration in the rate of speciation in the thalassoid gastropods of the lake following lake colonization. While limited within-lake speciation has occurred, the dramatic conchological diversity of gastropods presently found within the lake has evolved from at least four major lineages that pre-date its formation by as much as 40 Myr. At the same time, a widespread group of African gastropods appears to have evolved from taxa presently found in the lake. While Lake Tanganyika has been a cradle of speciation for cichlid fishes, it has also been an important evolutionary reservoir of gastropod lineages that have been extirpated outside the basin. PMID:15129964

  11. Discrimination among spawning concentrations of Lake Superior lake herring based on trace element profiles in sagittae

    USGS Publications Warehouse

    Bronte, Charles R.; Hesselberg, Robert J.; Shoesmith, John A.; Hoff, Michael H.

    1996-01-01

    Little is known about the stock structure of lake herring Coregonus artedi in Lake Superior, and recent increases in harvestable stock sizes has led to expanded exploitation in some areas. Research on marine teleosts has demonstrated that chemical differences in sagittal otoliths can be used for identification of fish stocks. We used plasma emission spectrophotometry to measure the concentrations of 10 trace elements in the sagittal otoliths from lake herring captured at eight spawning sites in Lake Superior and from Little Star Lake, an inland lake outside the Lake Superior basin. Discriminant function analysis indicated that elemental concentrations provided site-specific information but that considerable overlap existed among some locations, especially those in western Lake Superior. Correct classification rates varied from 12.0% to 86.1% and were generally higher for spawning locations from embayments in eastern Lake Superior and for the outgroup population from Little Star Lake. The results presented here demonstrate the potential usefulness of this technique for strictly freshwater species, especially those that live in highly oligotrophic waters such as Lake Superior.

  12. Preliminary evaluation of a lake whitefish (Coregonus clupeaformis) bioenergetics model

    USGS Publications Warehouse

    Madenjian, Charles P.; Pothoven, Steven A.; Schneeberger, Philip J.; O'Connor, Daniel V.; Brandt, Stephen B.

    2005-01-01

    We conducted a preliminary evaluation of a lake whitefish (Coregonus clupeaformis) bioenergetics model by applying the model to size-at-age data for lake whitefish from northern Lake Michigan. We then compared estimates of gross growth efficiency (GGE) from our bioenergetis model with previously published estimates of GGE for bloater (C. hoyi) in Lake Michigan and for lake whitefish in Quebec. According to our model, the GGE of Lake Michigan lake whitefish decreased from 0.075 to 0.02 as age increased from 2 to 5 years. In contrast, the GGE of lake whitefish in Quebec inland waters decreased from 0.12 to 0.05 for the same ages. When our swimming-speed submodel was replaced with a submodel that had been used for lake trout (Salvelinus namaycush) in Lake Michigan and an observed predator energy density for Lake Michigan lake whitefish was employed, our model predicted that the GGE of Lake Michigan lake whitefish decreased from 0.12 to 0.04 as age increased from 2 to 5 years.

  13. Evaluating integration of inland bathymetry in the U.S. Geological Survey 3D Elevation Program, 2014

    USGS Publications Warehouse

    Miller-Corbett, Cynthia

    2016-09-01

    the 3D Elevation Program so that data can be integrated with a minimal level of effort. Geomorphic site conditions are known to affect the success and accuracy of light detection and ranging and other bathymetric surveys, and a baseline that includes geomorphic data is recommended to help in evaluation of limitations imposed by geomorphology for surveys completed in the variable physiographic provinces across the United States. The geographic distribution for existing surveys identifies regions where inland bathymetry data have been collected and, conversely, where little or no survey data seem to be available to provide hydrologic and hydraulic information. This distribution, in conjunction with local to regional data needs to characterize and monitor river and lake resources, provides another important set of criteria to propose and guide acquisition of new bathymetry data for the 3D Elevation Program. An initial evaluation of needs can be based on the importance of water resources that provide primary water supplies for communities, agriculture, energy, and ecological systems; the importance of flood plain analyses; and projected population growth across the United States.

  14. Evaluating integration of inland bathymetry in the U.S. Geological Survey 3D Elevation Program, 2014

    USGS Publications Warehouse

    Miller-Corbett, Cynthia

    2016-01-01

    the 3D Elevation Program so that data can be integrated with a minimal level of effort. Geomorphic site conditions are known to affect the success and accuracy of light detection and ranging and other bathymetric surveys, and a baseline that includes geomorphic data is recommended to help in evaluation of limitations imposed by geomorphology for surveys completed in the variable physiographic provinces across the United States. The geographic distribution for existing surveys identifies regions where inland bathymetry data have been collected and, conversely, where little or no survey data seem to be available to provide hydrologic and hydraulic information. This distribution, in conjunction with local to regional data needs to characterize and monitor river and lake resources, provides another important set of criteria to propose and guide acquisition of new bathymetry data for the 3D Elevation Program. An initial evaluation of needs can be based on the importance of water resources that provide primary water supplies for communities, agriculture, energy, and ecological systems; the importance of flood plain analyses; and projected population growth across the United States.

  15. Role of exchange flow in salt water balance of Urmia Lake

    NASA Astrophysics Data System (ADS)

    Marjani, Aliasghar; Jamali, Mirmosadegh

    2014-03-01

    In this paper we examine how exchange flow in Urmia Lake plays a crucial role in dynamics of the lake. Urmia Lake, a very large hyper-saline lake of high ecological significance, is located in northwest of Iran with a 15-km causeway dividing it into north and south lakes. A 1250-m opening in the causeway near the east coast links the two lakes. The differences in mean water levels and densities of the two lakes increase in spring due to large freshwater inflows into the south lake. High evaporation dominates the lake in summer. By incorporating the results of a two-layer hydraulics theory into a mixing model of the lake, we show that the exchange flow through the opening diminishes the water level and salinity differences of the two lakes and hence helps restoration of the pre-construction state of the lake by the end of fall. The model results are confirmed by the field data. The north-south and south-north flows through the opening are equal in most of the year, except in spring when the south-north flow is greater due to the head difference of the two lakes.

  16. Microbial Quality of Tropical Inland Waters and Effects of Rainfall Events

    PubMed Central

    Tremblay, Raymond L.; Toledo-Hernandez, Carlos; Gonzalez-Nieves, Joel E.; Ryu, Hodon; Santo Domingo, Jorge W.; Toranzos, Gary A.

    2012-01-01

    Novel markers of fecal pollution in tropical waters are needed since conventional methods recommended for other geographical regions may not apply. To address this, the prevalence of thermotolerant coliforms, enterococci, coliphages, and enterophages was determined by culture methods across a watershed. Additionally, human-, chicken-, and cattle-specific PCR assays were used to identify potential fecal pollution sources in this watershed. An enterococcus quantitative PCR (qPCR) assay was tested and correlated with culture methods at three sites since water quality guidelines could incorporate this technique as a rapid detection method. Various rainfall events reported before sample collection at three sites were considered in the data analyses. Thermotolerant coliforms, enterococci, coliphages, and enterophages were detected across the watershed. Human-specific Bacteroides bacteria, unlike the cattle- and chicken-specific bacteria, were detected mostly at sites with the corresponding fecal impact. Enterococci were detected by qPCR as well, but positive correlations with the culture method were noted at two sites, suggesting that either technique could be used. However, no positive correlations were noted for an inland lake tested, suggesting that qPCR may not be suitable for all water bodies. Concentrations of thermotolerant coliforms and bacteriophages were consistently lower after rainfall events, pointing to a possible dilution effect. Rainfall positively correlated with enterococci detected by culturing and qPCR, but this was not the case for the inland lake. The toolbox of methods and correlations presented here could be potentially applied to assess the microbial quality of various water types. PMID:22610428

  17. Astrobiology of Antarctic ice Covered Lakes

    NASA Astrophysics Data System (ADS)

    Doran, P. T.; Fritsen, C. H.

    2005-12-01

    Antarctica contains a number of permanently ice-covered lakes which have often been used as analogs of purported lakes on Mars in the past. Antarctic subglacial lakes, such as Lake Vostok, have also been viewed as excellent analogs for an ice covered ocean on the Jovian moon Europa, and to a lesser extend on Mars. Lakes in the McMurdo Dry Valleys of East Antarctica have ice covers that range from 3 to 20 meters thick. Water salinities range from fresh to hypersaline. The thinner ice-covered lakes have a well-documented ecology that relies on the limited available nutrients and the small amount of light energy that penetrates the ice covers. The thickest ice-covered lake (Lake Vida in Victoria Valley) has a brine beneath 20 m of ice that is 7 times sea water and maintains a temperature below -10 degrees Celsius. This lake is vastly different from the thinner ice-covered lakes in that there is no communication with the atmosphere. The permanent ice cover is so thick, that summer melt waters can not access the sub-ice brine and so the ice grows from the top up, as well as from the bottom down. Brine trapped beneath the ice is believed to be ancient, stranded thousands of years ago when the ice grew thick enough to isolate it from the surface. We view Lake Vida as an excellent analog for the last aquatic ecosystem to have existed on Mars under a planetary cooling. If, as evidence is now increasingly supporting, standing bodies of water existed on Mars in the past, their fate under a cooling would be to go through a stage of permanent ice cover establishment, followed by a thickening of that ice cover until the final stage just prior to a cold extinction would be a Lake Vida-like lake. If dust storms or mass movements covered these ancient lakes, remnants may well be in existence in the subsurface today. A NASA Astrobiology Science and Technology for Exploring Planets (ASTEP) project will drill the Lake Vida ice cover and access the brine and sediments beneath in

  18. Model reactions and natural occurrence of furans from hypersaline environments

    NASA Astrophysics Data System (ADS)

    Krause, T.; Tubbesing, C.; Benzing, K.; Schöler, H. F.

    2013-11-01

    Volatile organic compounds like furan and its derivatives are important for atmospheric properties and reactions. In this paper the known abiotic formation of furan from catechol under Fenton-like conditions with Fe3+ sulphate was revised by the use of a bispidine Fe2+ complex as a~model compound for iron with well-known characteristics. While total yields were comparable to those with the Fe3+ salt, the turnover numbers of the active iron species increased. Additionally, the role of iron and pH will be discussed during furan formation from model compounds and in natural sediment and water samples collected from the Dead Sea and several salt lakes in Western Australia. Various alkylated furans and even traces of halogenated furans (3-chlorofuran and 3-bromofuran) were found in these samples. Furthermore, the emission of furans is compared to the abundance of several possible precursors such as isoprene and aromatic hydrocarbons as well as to the related thiophenes. It is assumed that the emissions of volatile organic compounds such as furans contribute to the formation of ultra fine particles in the vicinity of salt lakes and are therefore important for the local climate.

  19. Model reactions and natural occurrence of furans from hypersaline environments

    NASA Astrophysics Data System (ADS)

    Krause, T.; Tubbesing, C.; Benzing, K.; Schöler, H. F.

    2014-05-01

    Volatile organic compounds like furan and its derivatives are important for atmospheric properties and reactions. In this work the known abiotic formation of furan from catechol under Fenton-like conditions with Fe3+ sulfate was revised by the use of a bispidine Fe2+ complex as a model compound for iron with well-known characteristics. While total yields were comparable to those with the Fe3+ salt, the bispidine Fe2+ complex is a better catalyst as the turnover numbers of the active iron species were higher. Additionally, the role of iron and pH is discussed in relation to furan formation from model compounds and in natural sediment and water samples collected from the Dead Sea and several salt lakes in Western Australia. Various alkylated furans and even traces of halogenated furans (3-chlorofuran and 3-bromofuran) were found in some Australian samples. 3-chlorofuran was found in three sediments and four water samples, whereas 3-bromofuran was detected in three water samples. Further, the emission of furans is compared to the abundance of several possible precursors such as isoprene and aromatic hydrocarbons as well as to the related thiophenes. It is deduced that the emissions of volatile organic compounds such as furans contribute to the formation of ultra-fine particles in the vicinity of salt lakes and are important for the local climate.

  20. IX international conference on Salt Lake research: Research opportunities and management challenges

    PubMed Central

    Jellison, Robert

    2005-01-01

    The 9th International Conference on Salt Lake Research was held 26–30 September 2005 in Western Australia at the Curtin University of Technology, Perth, Australia. One hundred scientists from 10 countries presented research on a diverse array of topics highlighting research findings and opportunities, and management challenges associated with inland saline waters. Major emergent themes of the conference included modeling of ecosystem processes, microbial communities, and features of Western Australian inland saline environments, including current threats, conservation and management. PMID:16381606

  1. Association of a new type of gliding, filamentous, purple phototrophic bacterium inside bundles of Microcoleus chthonoplastes in hypersaline cyanobacterial mats

    NASA Technical Reports Server (NTRS)

    D'Amelio, E. D.; Cohen, Y.; Des Marais, D. J.

    1987-01-01

    An unidentified filamentous purple bacterium, probably belonging to a new genus or even a new family, is found in close association with the filamentous, mat-forming cyanobacterium Microcoleus chthonoplastes in a hypersaline pond at Guerrero Negro, Baja California Sur, Mexico, and in Solar Lake, Sinai, Egypt. This organism is a gliding, segmented trichome, 0.8-0.9 micrometer wide. It contains intracytoplasmic stacked lamellae which are perpendicular and obliquely oriented to the cell wall, similar to those described for the purple sulfur bacteria Ectothiorhodospira. These bacteria are found inside the cyanobacterial bundle, enclosed by the cyanobacterial sheath. Detailed transmission electron microscopical analyses carried out in horizontal sections of the upper 1.5 mm of the cyanobacterial mat show this cyanobacterial-purple bacterial association at depths of 300-1200 micrometers, corresponding to the zone below that of maximal oxygenic photosynthesis. Sharp gradients of oxygen and sulfide are established during the day at this microzone in the two cyanobacterial mats studied. The close association, the distribution pattern of this association and preliminary physiological experiments suggest a co-metabolism of sulfur by the two-membered community. This probable new genus of purple bacteria may also grow photoheterotrophically using organic carbon excreted by the cyanobacterium. Since the chemical gradients in the entire photic zone fluctuate widely in a diurnal cycle, both types of metabolism probably take place. During the morning and afternoon, sulfide migrates up to the photic zone allowing photoautotrophic metabolism with sulfide as the electron donor. During the day the photic zone is highly oxygenated and the purple bacteria may either use oxidized species of sulfur such as elemental sulfur and thiosulfate in the photoautotrophic mode or grow photoheterotrophically using organic carbon excreted by M. chthonoplastes. The new type of filamentous purple sulfur

  2. ICESat Observations of Inland Surface Water Stage, Slope, and Extent: a New Method for Hydrologic Monitoring

    NASA Technical Reports Server (NTRS)

    Harding, David J.; Jasinski, Michael F.

    2004-01-01

    River discharge and changes in lake, reservoir and wetland water storage are critical terms in the global surface water balance, yet they are poorly observed globally and the prospects for adequate observations from in-situ networks are poor (Alsdorf et al., 2003). The NASA-sponsored Surface Water Working Group has established a framework for advancing satellite observations of river discharge and water storage changes which focuses on obtaining measurements of water surface height (stage), slope, and extent. Satellite laser altimetry, which can achieve centimeter-level elevation precision for single, small laser footprints, provides a method to obtain these inland water parameters and contribute to global water balance monitoring. Since its launch in January, 2003 the Ice, Cloud, and land Elevation Satellite (ICESat), a NASA Earth Observing System mission, has achieved over 540 million laser pulse observations of ice sheet, ocean surface, land topography, and inland water elevations and cloud and aerosol height distributions. By recording the laser backscatter from 80 m diameter footprints spaced 175 m along track, ICESat acquires globally-distributed elevation profiles, using a 1064 nm laser altimeter channel, and cloud and aerosol profiles, using a 532 nm atmospheric lidar channel. The ICESat mission has demonstrated the following laser altimeter capabilities relevant to observations of inland water: (1) elevation measurements with a precision of 2 to 3 cm for flat surfaces, suitable for detecting river surface slopes along long river reaches or between multiple crossings of a meandering river channel, (2) from the laser backscatter waveform, detection of water surface elevations beneath vegetation canopies, suitable for measuring water stage in flooded forests, (3) single pulse absolute elevation accuracy of about 50 cm (1 sigma) for 1 degree sloped surfaces, with calibration work in progress indicating that a final accuracy of about 12 cm (1 sigma) will be

  3. Great Salt Lake Microbial Communities: The Foundation of a Terminal Lake Ecosystem

    NASA Astrophysics Data System (ADS)

    Baxter, B. K.; Acord, M.; Riddle, M. R.; Avery, B.

    2006-12-01

    Great Salt Lake (GSL) is a natural hypersaline ecosystem and a terminal lake of substantial size. The dramatic fluctuation in water levels and salinity creates an ecological backdrop selective for organisms with a high degree of adaptability. At the macro level, the biodiversity of the GSL ecosystem is simple, due to the limitations of an extreme saline environment: Birds eat the two invertebrates of the lake, and the invertebrates eat phytoplankton. However, analysis of the microbial level reveals an enormous diversity of species interacting with one another and the ecosystem as a whole. Our cultivation, biochemical tests, microscopy and DNA sequencing yielded data on dozens of isolates. These data demonstrate novel species, and possibly genera, living in the lake. In addition, we have discovered viruses (bacteriophage) that prey on the microorganisms. Preliminary data on bacteria dwelling in the gut of the brine shrimp, Artemia franciscana, link these prokaryotic organisms to the food chain for the first time. All of these results taken together open the door for the discussion of the significance of the microbial level of terminal lake ecosystem, particularly in light of lake water contamination and bioremediation possibilities.

  4. Magnitude and Significance of Carbon Burial in Lakes, Reservoirs, and Northern Peatlands

    USGS Publications Warehouse

    U.S. Geological Survey

    1999-01-01

    It is estimated that freshwater lakes in the world have a total area of about 1.5x1012 m2 (Shiklomanov, 1993; table 1). Including saline inland seas in this total would add another 1x1012 m2. The 28 largest (area of each > 5,000 km2) freshwater lakes in the world have a total area of 1.18x1012 m2 or about 79 percent of the total area of all freshwater lakes. If the 28 large lakes bury organic carbon (OC), on average, at the same rate as Lake Michigan (5 g/m2/yr), then the annual rate of OC burial in these 28 lakes is about 6 Tg/yr (6 terragrams per year or 6x1012 g/yr; table 1). If the smaller lakes bury OC, on average, at the same rate as an average Minnesota lake (72 g/m2/yr), then the annual rate of OC accumulation in these smaller lakes is about 23 Tg/yr (23x1012 g/yr; table 1). If saline inland seas bury OC at the Lake Michigan rate, this would be an additional 5 Tg/yr, for a total of 34 Tg/yr for all freshwater lakes and saline inland seas (table 1). Mulholland and Elwood (1982) estimated the OC burial in all lakes and inland seas (excluding the Black Sea) to be 60 Tg/yr today (table 1) and an average of 20 Tg/yr for the last 10,000 years. Stallard (1998) modeled terrestrial sedimentation as a series of 864 scenarios. For lake area, he used 1.54x1012 m2, the area of the 250 largest lakes in the world. This is close to the total of large and small lakes given in table 1. Again, including inland seas to this total would add an additional 1x1012 m2. Results of scenarios for lakes and reservoirs were divided into two components, those with clastic sediments and those with organic sediments. The results of OC burial in the most likely of Stallard's scenarios for lakes range from 48 to 72 Tg/yr (table 1), the average of which is close to the 60 Tg/yr estimated by Mulholland and Elwood (1982). We will use an average of 54 Tg/yr (table 1). The closeness of these estimates, calculated by different methods, suggests that this value is not in error by more than a factor

  5. Blow-down and blow-in of Inland`s No. 7 blast furnace

    SciTech Connect

    Ricketts, J.; Quisenberry, P.; Carter, W.

    1995-12-01

    After extensive and detailed planning, a mini-reline of the 13.7 meter No. 7 Blast Furnace was executed in November 1993. The furnace lining had 18 million metric tons of production and the bosh, belly and lower stack lining were being maintained through a scheduled grouting practice. The mini-reline was planned for 33 days and the reline work included (a) replacing the bosh, belly and lower stack alumina lining with graphite brick, (b) gunning the middle and upper stack, (c) rebuilding the furnace top, stove burners and tapholes and (d) minor repairs to other auxiliary equipment. During this 33 day reline period the two 8 meter furnaces could only produce 40% of the normal production requirement, therefore the blow-down, quench, salamander tap and blow-in activities were critical to meeting the planned schedule. The planning of these activities was started in the spring of 1993 and included review of Inland`s past blow-down and blow-in performance as well as bench marking the performance of other large blast furnaces in North America, Japan and Europe. The development of the 1993 procedures focused on opportunities to accelerate the blow-down, quench, salamander tap and blow-in as well as having a clean hearth and stack which could also save time during the demolition phase of the reline. Any time that could be saved in these activities directly translated to an early start-up and more plantwide production. This paper will cover the successful planning and implementation of these activities which resulted in a 2 day reduction in the reline schedule, an accelerated production curve and an earlier than planned use of PCI during blow-in.

  6. Fungal life in the extremely hypersaline water of the Dead Sea: first records.

    PubMed Central

    Buchalo, A S; Nevo, E; Wasser, S P; Oren, A; Molitoris, H P

    1998-01-01

    The first report, to our knowledge, on the occurrence of filamentous fungi in the hypersaline (340 g salt l-1) Dead Sea is presented. Three species of filamentous fungi from surface water samples of the Dead Sea were isolated: Gymnascella marismortui (Ascomycota), which is described as a new species, Ulocladium chlamydosporum and Penicillium westlingii (Deuteromycota). G. marismortui and U. chlamydosporum grew on media containing up to 50% Dead Sea water. G. marismortui was found to be an obligate halophile growing optimally in the presence of 0.5-2 M NaCl or 10 30% (by volume) of Dead Sea water. Isolated cultures did not grow on agar media without salt, but grew on agar prepared with up to 50% Dead Sea water. This suggests that they may be adapted to life in the extremely stressful hypersaline Dead Sea. PMID:9721690

  7. Dependence of juvenile reef fishes on semi-arid hypersaline estuary microhabitats as nurseries.

    PubMed

    Sales, N S; Dias, T L P; Baeta, A; Pessanha, A L M

    2016-07-01

    The differences between fish assemblages in three microhabitat types, in relation to vegetation and sediment characteristics of a hypersaline estuary located in an semi-arid zone in north-eastern Brazil, were investigated. Fishes were collected using a beach seine during the rainy and dry seasons in 2012. A total of 78 species were recorded, with the most common families being Gerreidae, Lutjanidae and Tetraodontidae. The majority of species were represented by juveniles, with Eucinostomus argenteus, Ulaema lefroyi and Sphoeroides greeleyi being the dominant species. The fish assemblage structures differed significantly among microhabitat types, with the narrow intertidal flat adjacent to the mangrove fringe supporting the most diverse fish fauna. In addition, only 27 species were common to all of the microhabitats. The results support the hypothesis that hypersaline estuaries serve as important nursery areas for various reef fish species, due to the structural complexity provided by their macroalgae beds and mangroves. PMID:27237742

  8. Dependence of juvenile reef fishes on semi-arid hypersaline estuary microhabitats as nurseries.

    PubMed

    Sales, N S; Dias, T L P; Baeta, A; Pessanha, A L M

    2016-07-01

    The differences between fish assemblages in three microhabitat types, in relation to vegetation and sediment characteristics of a hypersaline estuary located in an semi-arid zone in north-eastern Brazil, were investigated. Fishes were collected using a beach seine during the rainy and dry seasons in 2012. A total of 78 species were recorded, with the most common families being Gerreidae, Lutjanidae and Tetraodontidae. The majority of species were represented by juveniles, with Eucinostomus argenteus, Ulaema lefroyi and Sphoeroides greeleyi being the dominant species. The fish assemblage structures differed significantly among microhabitat types, with the narrow intertidal flat adjacent to the mangrove fringe supporting the most diverse fish fauna. In addition, only 27 species were common to all of the microhabitats. The results support the hypothesis that hypersaline estuaries serve as important nursery areas for various reef fish species, due to the structural complexity provided by their macroalgae beds and mangroves.

  9. Removal performance and microbial communities in a sequencing batch reactor treating hypersaline phenol-laden wastewater.

    PubMed

    Jiang, Yu; Wei, Li; Zhang, Huining; Yang, Kai; Wang, Hongyu

    2016-10-01

    Hypersaline phenol-rich wastewater is hard to be treated by traditional biological systems. In this work, a sequencing batch reactor was used to remove phenol from hypersaline wastewater. The removal performance was evaluated in response to the variations of operating parameters and the microbial diversity was investigated by 454 pyrosequencing. The results showed that the bioreactor had high removal efficiency of phenol and was able to keep stable with the increase of initial phenol concentration. DO, pH, and salinity also affected the phenol removal rate. The most abundant bacterial group was phylum Proteobacteria in the two working conditions, and class Gammaproteobacteria as well as Alphaproteobacteria was predominant subgroup. The abundance of bacterial clusters was notably different along with the variation of operation conditions, resulting in changes of phenol degradation rates. The high removal efficiency of phenol suggested that the reactor might be promising in treating phenol-laden industrial wastewater in high-salt condition. PMID:27359064

  10. Evidence of novel phylogenetic lineages of methanogenic archaea from hypersaline microbial mats.

    PubMed

    García-Maldonado, José Q; Bebout, Brad M; Everroad, R Craig; López-Cortés, Alejandro

    2015-01-01

    Methanogenesis in hypersaline and high-sulfate environments is typically dominated by methylotrophic methanogens because sulfate reduction is thermodynamically favored over hydrogenotrophic methanogenesis in these environments. We characterized the community composition of methanogenic archaea in both unmanipulated and incubated microbial mats from different hypersaline environments in Baja California Sur, Mexico. Clone libraries of methyl coenzyme-M reductase (mcrA) sequences and DGGE band patterns of 16S rRNA and mcrA sequences showed that the methanogen community in these microbial mats is dominated by methylotrophic methanogens of the genus Methanohalophilus. However, phylogenetic analyses of mcrA sequences from these mats also revealed two new lineages corresponding to putative hydrogenotrophic methanogens related with the strictly hydrogenotrophic order Methanomicrobiales. Stimulated methane production under decreased salinity and sulfate concentrations also suggested the presence of hydrogenotrophic methanogens in these samples. The relative abundance of mcrA gene and transcripts, estimated by SYBR green I qPCR assays, suggested the activity of different phylogenetic groups of methanogens, including the two novel clusters, in unmanipulated samples of hypersaline microbial mats. Using geochemical and molecular approaches, we show that substrate limitation and values of salinity and sulfate higher than 3 % and 25 mM (respectively) are potential environmental constraints for methanogenesis in these environments. Microcosm experiments with modifications of salinity and sulfate concentrations and TMA addition showed that upper salt and sulfate concentrations for occurrence of methylotrophic methanogenesis were 28 % and 263 mM, respectively. This study provides phylogenetic information about uncultivated and undescribed methanogenic archaea from hypersaline environments.

  11. Microbial eukaryotes in the hypersaline anoxic L'Atalante deep-sea basin.

    PubMed

    Alexander, Eva; Stock, Alexandra; Breiner, Hans-Werner; Behnke, Anke; Bunge, John; Yakimov, Michail M; Stoeck, Thorsten

    2009-02-01

    The frontiers of eukaryote life in nature are still unidentified. In this study, we analysed protistan communities in the hypersaline (up to 365 g l(-1) NaCl) anoxic L'Atalante deep-sea basin located in the eastern Mediterranean Sea. Targeting 18S ribosomal RNA retrieved from the basin's lower halocline (3501 m depth) we detected 279 protistan sequences that grouped into 42 unique phylotypes (99% sequence similarity). Statistical analyses revealed that these phylotypes account only for a proportion of the protists inhabiting this harsh environment with as much as 50% missed by this survey. Most phylotypes were affiliated with ciliates (45%), dinoflagellates (21%), choanoflagelates (10%) and uncultured marine alveolates (6%). Sequences from other taxonomic groups like stramenopiles, Polycystinea, Acantharea and Euglenozoa, all of which are typically found in non-hypersaline deep-sea systems, are either missing or very rare in our cDNA clone library. Although many DHAB sequences fell within previously identified environmental clades, a large number branched relatively deeply. Phylotype richness, community membership and community structure differ significantly from a deep seawater reference community (3499 m depth). Also, the protistan community in the L'Atalante basin is distinctively different from any previously described hypersaline community. In conclusion, we hypothesize that extreme environments may exert a high selection pressure possibly resulting in the evolution of an exceptional and distinctive assemblage of protists. The deep hypersaline anoxic basins in the Mediterranean Sea provide an ideal platform to test for this hypothesis and are promising targets for the discovery of undescribed protists with unknown physiological capabilities.

  12. Microbial eukaryotes in the hypersaline anoxic L'Atalante deep-sea basin.

    PubMed

    Alexander, Eva; Stock, Alexandra; Breiner, Hans-Werner; Behnke, Anke; Bunge, John; Yakimov, Michail M; Stoeck, Thorsten

    2009-02-01

    The frontiers of eukaryote life in nature are still unidentified. In this study, we analysed protistan communities in the hypersaline (up to 365 g l(-1) NaCl) anoxic L'Atalante deep-sea basin located in the eastern Mediterranean Sea. Targeting 18S ribosomal RNA retrieved from the basin's lower halocline (3501 m depth) we detected 279 protistan sequences that grouped into 42 unique phylotypes (99% sequence similarity). Statistical analyses revealed that these phylotypes account only for a proportion of the protists inhabiting this harsh environment with as much as 50% missed by this survey. Most phylotypes were affiliated with ciliates (45%), dinoflagellates (21%), choanoflagelates (10%) and uncultured marine alveolates (6%). Sequences from other taxonomic groups like stramenopiles, Polycystinea, Acantharea and Euglenozoa, all of which are typically found in non-hypersaline deep-sea systems, are either missing or very rare in our cDNA clone library. Although many DHAB sequences fell within previously identified environmental clades, a large number branched relatively deeply. Phylotype richness, community membership and community structure differ significantly from a deep seawater reference community (3499 m depth). Also, the protistan community in the L'Atalante basin is distinctively different from any previously described hypersaline community. In conclusion, we hypothesize that extreme environments may exert a high selection pressure possibly resulting in the evolution of an exceptional and distinctive assemblage of protists. The deep hypersaline anoxic basins in the Mediterranean Sea provide an ideal platform to test for this hypothesis and are promising targets for the discovery of undescribed protists with unknown physiological capabilities. PMID:18826436

  13. Characterization of a moderately halo-acidophilic bacterium isolated from Lake Brown, western Australia

    NASA Astrophysics Data System (ADS)

    Mormile, Melanie R.; Hong, Bo-young; Adams, Nicholas T.; Benison, Kathleen C.; Oboh-Ikuenobe, Francisca

    2007-09-01

    Compared to prevalent alkaline to neutral hypersaline environments, acidic hypersaline environments have been scarcely studied. However, they hold interest to many researchers in that these environments have similar geological and geochemical characteristics as those found in lithified strata on Mars. Fieldwork indicated that Lake Brown, located in Western Australia, possessed pH values of 3.1-4.5 and salinity between 13.0-23.0%. Water column, groundwater, and sediment samples were collected from the lake during the austral winter of 2005. These samples were analyzed with both traditional culture and molecular methods. Modified growth media and minimal media were designed to match the composition (Cl, Na, Mg, SO4, K, Ca, and Br) of Lake Brown surface and ground waters for the enrichment of microorganisms. One of the isolates obtained, Brown 1, can grow in media that possesses pH values of 3-7 with optimal growth at pH 4, salinity that ranged from 5% to saturation with optimal growth at 5% and could grow under temperatures that ranged from 20°C to 65°C with optimal grow occurring at 37°C. The isolate's optimum growth conditions are similar to those found in Lake Brown. The isolate is a Gram-negative rod that forms yellow colonies on 17% Phytogel. Its 16S rRNA gene can be amplified with bacterial primers but not with archaeal primers. Its 16S rRNA gene sequence suggests that the isolate is a gamma proteobacterium. Studies on organisms isolated from environments such as Lake Brown, an acid hypersaline lake, can provide an opportunity to both expand our knowledge of terrestrial extremophiles and gain insight on the possible forms of life that might have existed on Mars.

  14. The density-driven circulation of the coastal hypersaline system of the Great Barrier Reef, Australia.

    PubMed

    Salamena, Gerry G; Martins, Flávio; Ridd, Peter V

    2016-04-15

    The coastal hypersaline system of the Great Barrier Reef (GBR) in the dry season, was investigated for the first time using a 3D baroclinic model. In the shallow coastal embayments, salinity increases to c.a. 1‰ above typical offshore salinity (~35.4‰). This salinity increase is due to high evaporation rates and negligible freshwater input. The hypersalinity drifts longshore north-westward due to south-easterly trade winds and may eventually pass capes or headlands, e.g. Cape Cleveland, where the water is considerably deeper (c.a. 15m). Here, a pronounced thermohaline circulation is predicted to occur which flushes the hypersalinity offshore at velocities of up to 0.08m/s. Flushing time of the coastal embayments is around 2-3weeks. During the dry season early summer, the thermohaline circulation reduces and therefore, flushing times are predicted to be slight longer due to the reduced onshore-offshore density gradient compared to that in the dry season winter period. PMID:26880128

  15. The density-driven circulation of the coastal hypersaline system of the Great Barrier Reef, Australia.

    PubMed

    Salamena, Gerry G; Martins, Flávio; Ridd, Peter V

    2016-04-15

    The coastal hypersaline system of the Great Barrier Reef (GBR) in the dry season, was investigated for the first time using a 3D baroclinic model. In the shallow coastal embayments, salinity increases to c.a. 1‰ above typical offshore salinity (~35.4‰). This salinity increase is due to high evaporation rates and negligible freshwater input. The hypersalinity drifts longshore north-westward due to south-easterly trade winds and may eventually pass capes or headlands, e.g. Cape Cleveland, where the water is considerably deeper (c.a. 15m). Here, a pronounced thermohaline circulation is predicted to occur which flushes the hypersalinity offshore at velocities of up to 0.08m/s. Flushing time of the coastal embayments is around 2-3weeks. During the dry season early summer, the thermohaline circulation reduces and therefore, flushing times are predicted to be slight longer due to the reduced onshore-offshore density gradient compared to that in the dry season winter period.

  16. Oxygen isotope composition of Holocene dolomite formed in humid hypersaline setting

    SciTech Connect

    Major, R.P.; Lucia, F.J. ); Lloyd, R.M.

    1992-07-01

    Holocene dolomite forming in supratidal carbonate sediments of Bonaire, Netherlands Antilles, is precipitated from hypersaline fluids in which the Mg:Ca ratio is elevated by evaporation and gypsum precipitation. Kinetic effects and water-vapor exchange between the humid atmosphere and hypersaline brines limit the {delta}{sup 18}O{sub water} values of the brines between +0.7{per thousand} and +2.1{per thousand} standard mean ocean water. The mean {delta}{sup 18}O value of dolomite is +1.0{per thousand} Peedee belemnite (n = 8), which is lower than values of dolomite precipitated from hypersaline brines in less humid environments. Bonaire dolomite is also isotopically lighter than dolomites interpreted to have formed in normal marine waters and mixed marine and/or meteoric waters. Calculated fractionation between dolomite and calcite formed from Bonaire brines is between 1.5{per thousand} and 3.5{per thousand}. The high end of this range is consistent with previously proposed mineralogic fractionations of 3{per thousand} {plus minus} 1{per thousand} and 3.2{per thousand} between dolomite and calcite.

  17. Anaerobic oxidation of methane by sulfate in hypersaline groundwater of the Dead Sea aquifer.

    PubMed

    Avrahamov, N; Antler, G; Yechieli, Y; Gavrieli, I; Joye, S B; Saxton, M; Turchyn, A V; Sivan, O

    2014-11-01

    Geochemical and microbial evidence points to anaerobic oxidation of methane (AOM) likely coupled with bacterial sulfate reduction in the hypersaline groundwater of the Dead Sea (DS) alluvial aquifer. Groundwater was sampled from nine boreholes drilled along the Arugot alluvial fan next to the DS. The groundwater samples were highly saline (up to 6300 mm chlorine), anoxic, and contained methane. A mass balance calculation demonstrates that the very low δ(13) CDIC in this groundwater is due to anaerobic methane oxidation. Sulfate depletion coincident with isotope enrichment of sulfur and oxygen isotopes in the sulfate suggests that sulfate reduction is associated with this AOM. DNA extraction and 16S amplicon sequencing were used to explore the microbial community present and were found to be microbial composition indicative of bacterial sulfate reducers associated with anaerobic methanotrophic archaea (ANME) driving AOM. The net sulfate reduction seems to be primarily controlled by the salinity and the available methane and is substantially lower as salinity increases (2.5 mm sulfate removal at 3000 mm chlorine but only 0.5 mm sulfate removal at 6300 mm chlorine). Low overall sulfur isotope fractionation observed ((34) ε = 17 ± 3.5‰) hints at high rates of sulfate reduction, as has been previously suggested for sulfate reduction coupled with methane oxidation. The new results demonstrate the presence of sulfate-driven AOM in terrestrial hypersaline systems and expand our understanding of how microbial life is sustained under the challenging conditions of an extremely hypersaline environment. PMID:25039851

  18. Dissimilatory sulfate reduction in hypersaline coastal pans: Activity across a salinity gradient

    NASA Astrophysics Data System (ADS)

    Porter, Donovan; Roychoudhury, Alakendra N.; Cowan, Donald

    2007-11-01

    The impact of salinity on the metabolic activity of sulfate-reducing bacteria in five highly saline to hypersaline coastal pans was studied using a radioactive tracer (35SO42-) technique. We recorded sulfate reduction at in situ porewater salinities of up to 422. Furthermore, enumeration of sulfate reduction rates in whole core incubations conducted under in situ conditions suggested a high variability in the activity of sulfate-reducers. Average reduction rates (27-3685 nmol cm -3 d -1) varied according to depth, season and site sampled. The highest reduction rates measured in the hypersaline pan were comparable to the highest reported rates from highly productive salt marsh and microbial mat ecosystems. Correspondingly, the depth-integrated rates (integrated to 12 cm) varied from 6 to 241 mmol m -2 d -1 and were also among the highest ever reported rates. The reduction rates decreased down-core and, surprisingly, were highest in the winter season when the lowest sediment temperatures were encountered. High salt concentrations did not inhibit sulfate reduction rates. Rather, higher rates were measured at pans with higher in situ salinities. In laboratory slurry incubation experiments, sediments from the saltpans were treated with increasing salt concentrations. Regression analysis suggested that the short term response of microbial consortia to up-shock was an increase in sulfate reduction activity up to salinities of 272-311 and 134-244, in hypersaline and highly saline pans, respectively. Beyond these salinities, the cells showed evidence of reduced activities.

  19. Anaerobic oxidation of methane by sulfate in hypersaline groundwater of the Dead Sea aquifer.

    PubMed

    Avrahamov, N; Antler, G; Yechieli, Y; Gavrieli, I; Joye, S B; Saxton, M; Turchyn, A V; Sivan, O

    2014-11-01

    Geochemical and microbial evidence points to anaerobic oxidation of methane (AOM) likely coupled with bacterial sulfate reduction in the hypersaline groundwater of the Dead Sea (DS) alluvial aquifer. Groundwater was sampled from nine boreholes drilled along the Arugot alluvial fan next to the DS. The groundwater samples were highly saline (up to 6300 mm chlorine), anoxic, and contained methane. A mass balance calculation demonstrates that the very low δ(13) CDIC in this groundwater is due to anaerobic methane oxidation. Sulfate depletion coincident with isotope enrichment of sulfur and oxygen isotopes in the sulfate suggests that sulfate reduction is associated with this AOM. DNA extraction and 16S amplicon sequencing were used to explore the microbial community present and were found to be microbial composition indicative of bacterial sulfate reducers associated with anaerobic methanotrophic archaea (ANME) driving AOM. The net sulfate reduction seems to be primarily controlled by the salinity and the available methane and is substantially lower as salinity increases (2.5 mm sulfate removal at 3000 mm chlorine but only 0.5 mm sulfate removal at 6300 mm chlorine). Low overall sulfur isotope fractionation observed ((34) ε = 17 ± 3.5‰) hints at high rates of sulfate reduction, as has been previously suggested for sulfate reduction coupled with methane oxidation. The new results demonstrate the presence of sulfate-driven AOM in terrestrial hypersaline systems and expand our understanding of how microbial life is sustained under the challenging conditions of an extremely hypersaline environment.

  20. Dispersion and transport of hypersaline gravity currents in the presence of internal waves at a pycnocline

    NASA Astrophysics Data System (ADS)

    Hogg, C. A. R.; Pietrasz, V. B.; Ouellette, N. T.; Koseff, J. R.

    2015-12-01

    Desalination of seawater offers a source of potable water in arid regions and during drought. However, hypersaline discharge from desalination facilities presents environmental risks, particularly to benthic organisms. The risks posed by salt levels and chemical additives, which can be toxic to local ecosystems, are typically mitigated by ensuring high levels of dilution close to the source. We report on laboratory flume experiments examining how internal waves at the pycnocline of a layered ambient density stratification influence the transport of hypersaline effluent moving as a gravity current down the slope. We found that some of the hypersaline fluid from the gravity current was diverted away from the slope into an intrusion along the pycnocline. A parametric study investigated how varying the energy of the internal wave altered the amount of dense fluid that was diverted into the pycnocline intrusion. The results are compared to an analytical framework that compares the incident energy in the internal wave to potential energy used in diluting the gravity current. These results are significant for desalination effluents because fluid diverted into the intrusion avoids the ecologically sensitive benthic layer and disperses more quickly than if it had continued to propagate along the bed.

  1. Trophic ecology and food consumption of fishes in a hypersaline tropical lagoon.

    PubMed

    Almeida-Silva, P H; Tubino, R A; Zambrano, L C; Hunder, D A; Garritano, S R; Monteiro-Neto, C

    2015-06-01

    This study evaluated the trophic ecology (diet composition, trophic strategy, similarities and overlap between species, feeding period and food consumption) of six benthivorous fish species in Araruama Lagoon, the largest hypersaline tropical lagoon on the east coast of South America, with an area of 210 km(2) and an average salinity of 52. The burrfish Chilomycterus spinosus fed on Anomalocardia flexuosa shell deposits, ingesting associated fauna. The caitipa mojarra Diapterus rhombeus differed from all other species, having not only the highest proportions of algae and Nematoda, but also feeding on polychaete tentacles. The two mojarras Eucinostomus spp. showed similar trophic strategies, feeding mostly on Polychaeta. The corocoro grunt Orthopristis ruber also fed mainly on Polychaeta, but differed from Eucinostomus spp. in secondary items. The whitemouth croacker Micropogonias furnieri fed mainly on small Crustacea at night, showing a high number of secondary prey items with low frequencies and high prey-specific abundance. The daily food consumption (g food g(-1) fish mass) for Eucinostomus argenteus was 0·012 and was 0·031 and 0·027 for M. furnieri in two different sampling events. The diet similarities between Araruama Lagoon and other brackish and marine environments indicate that hypersalinity is not a predominant factor shaping the trophic ecology of fishes in this lagoon. The stability of hypersaline conditions, without a pronounced gradient, may explain the presence of several euryhaline fishes and invertebrates well adapted to this condition, resulting in a complex food web.

  2. Tracing groundwater input into Lake Vanda, Wright Valley, Antarctica using major ions, stable isotopes and noble gas

    NASA Astrophysics Data System (ADS)

    Dowling, C. B.; Poreda, R. J.; Snyder, G. T.

    2008-12-01

    The McMurdo Dry Valleys (MDV), Antarctica, is the largest ice-free region on Antarctica. Lake Vanda, located in central Wright Valley, is the deepest lake among the MDV lakes. It has a relatively fresh water layer above 50 m with a hypersaline calcium-chloride brine below (50-72 m). The Onyx River is the only stream input into Lake Vanda. It flows westward from the coastal Lower Wright Glacier and discharges into Lake Vanda. Suggested by the published literature and this study, there has been and may still be groundwater input into Lake Vanda. Stable isotopes, major ions, and noble gas data from this study coupled with previously published data indicate that the bottom waters of Lake Vanda have had significant contributions from a deep groundwater system. The dissolved gas of the bottom waters of Lake Vanda display solubility concentrations rather than the Ar-enriched dissolved gas seen in the Taylor Valley lakes (such as Lake Bonney). The isotopic data indicate that the bottom calcium-chloride-brine of Lake Vanda has undergone very little evaporation. The calcium-chloride chemistry of the groundwater that discharges into Lake Vanda most likely results from the chemical weathering and dissolution of cryogenic evaporites (antarcticite and gypsum) within the glacial sediments of Wright Valley. The high calcium concentrations of the brine have caused gypsum to precipitate on the lake bottom. Our work also supports previous physical and chemical observations suggesting that the upper portion actively circulates and the hypersaline bottom layer does not. The helium and calcium chloride values are concentrated at the bottom, with a very narrow transition layer between it and the above fresh water. If the freshwater layer did not actively circulate, then diffusion over time would have caused the helium and calcium chloride to slowly permeate upwards through the water column.

  3. Neonatal birth weight variations between inland and littoral Croatia.

    PubMed

    Bralić, Irena; Rodin, Urelija; Matanić, Dubravka; Jovancevic, Milivoj

    2010-09-01

    The aim of the study was to assess neonatal birth weight (BW) differences between inland and littoral Croatia, to identify BW groups with most pronounced differences, and possible variations in the rate of BW > or = 4000 g between Sibenik area and the rest of littoral (counties with access to the Adriatic Sea) and inland Croatia. The study included data on 99.42% of 200,740 live births recorded in 37 Croatian maternity hospitals during the 2001-2005 period. Distribution of 500-g BW groups was analyzed irrespective of neonatal sex and gestational age. Differences were found between the inland and littoral parts of Croatia according to distribution of the BW groups of < 2500 g (5.4% vs. 4.4%), 2500-3999 g (84% vs. 80.2%) and > or = 4000 g (10.6% vs. 15.4%) (chi2 = 882; p < 0.001).The highest rate of BW > or = 4000 g was recorded in Sibenik-Knin County (5-year mean 18.32%) and was greater throughout the littoral as compared with inland Croatia (5-year mean 14.99% vs. 9.58%). A shift towards higher BWgroups recorded throughout littoral as compared with inland Croatia supports the hypothesis on variation in anthropologic characteristics in the respective populations to be pronounced as early as at birth. Study results confirmed fetal macrosomia not to be exclusively characteristic of Sibenik-Knin County, since the rate of neonatal BW > or =4000 g was significantly higher in the entire littoral as compared with inland Croatia.

  4. Heavy metal tolerance of inland saltgrass (Distichlis spicata)

    SciTech Connect

    Prodgers, R.A.; Inskeep, W.P. )

    1991-09-01

    Inland saltgrass (Distichlis spicata) occurs on at least two metal-contaminated sites in southwestern Montana. As a result of mining, milling, and smelting activities, soils have elevated concentrations of copper, zinc, and manganese. One soil is acidic (upper horizons), slightly saline, and moderately sodic. The other soil is alkaline, nonsaline, and nonsodic. The fact that inland saltgrass grows on these soils and does not accumulate dangerous levels of metals makes it a candidate species for revegetating hardrock mining and other metal-polluted sites.

  5. Inland diatoms from the McMurdo Dry Valleys and James Ross Island, Antarctica

    USGS Publications Warehouse

    Esposito, R.M.M.; Spaulding, S.A.; McKnight, Diane M.; Van De Vijver, B.; Kopalova, K.; Lubinski, D.; Hall, B.; Whittaker, T.

    2008-01-01

    Diatom taxa present in the inland streams and lakes of the McMurdo Dry Valleys and James Ross Island, Antarctica, are presented in this paper. A total of nine taxa are illustrated, with descriptions of four new species (Luticola austroatlantica sp. nov., Luticola dolia sp. nov., Luticola laeta sp. nov., Muelleria supra sp. nov.). In the perennially ice-covered lakes of the McMurdo Dry Valleys, diatoms are confined to benthic mats within the photic zone. In streams, diatoms are attached to benthic surfaces and within the microbial mat matrix. One species, L. austroatlantica, is found on James Ross Island, of the southern Atlantic archipelago, and the McMurdo Dry Valleys. The McMurdo Dry Valley populations are at the lower range of the size spectrum for the species. Streams flow for 6-10 weeks during the austral summer, when temperatures and solar radiation allow glacial ice to melt. The diatom flora of the region is characterized by species assemblages favored under harsh conditions, with naviculoid taxa as the dominant group and several major diatom groups conspicuously absent. ?? 2008 NRC.

  6. A note on the biogeographical origin of the brine shrimp Artemia urmiana Günther, 1899 from Urmia Lake, Iran.

    PubMed

    Eimanifar, Amin; Asem, Alireza; Djamali, Morteza; Wink, Michael

    2016-01-01

    The brine shrimp Artemia urmiana, an abundant inhabitant of the hypersaline Urmia Lake in northwestern Iran, has recently been described from Lake Koyashskoe, also a shallow hypersaline lake that is located on the Black Sea coast of the Crimean Peninsula (Ukraine). This discovery has questioned the endemicity of A. urmiana in Urmia Lake and has also brought into question the biogeographical origin of this species. In the present study, we combined recent genetic divergence data (mtDNA-COI) with palaeoecological evidence to address the biogeographical origin of A. urmiana. Calibration of the molecular clock of the COI region was set by assigning the age of the micro-crustacean Daphnia pulex minimally at 145 Mya. The divergence age of A. urmiana in Urmia Lake dates back to 383,000 years, whereas Ukrainian Artemia reflects a very young populations that diverged about 196,000 years ago. Palaeoecological evidence suggests that the age of the major habitat of A. urmiana i.e. Urmia Lake goes back to the Tertiary Period while the Ukranian habitats of the species are very young, by virtue of geological features of the Holocene age. We conclude that the biogeographical origin of A. urmiana is outside of Europe and the current state of knowledge strongly suggests that Urmia Lake has been the major source of its expansion into its modern habitats in Europe. PMID:27394547

  7. Eutrophic lakes as CO2 sinks - A survey of 19 lakes in India

    NASA Astrophysics Data System (ADS)

    Singh, G.

    2015-12-01

    Inland waters emit a substantial amount of CO2 every year, most recent syntheses estimate (Raymond et al. 2013, IPCC 2013). However, eutrophic water bodies, which constitute the majority of inland waters, are underrepresented in these syntheses and may absorb rather than emit CO2 because of their high productivity (Balmer and Downing 2011, Pacheco et al. 2013). We did a survey of 19 urban and peri-urban lakes in India across a wide range of climates and with varying levels of eutrophication to get a snapshot of lake air-water CO2 exchange. A majority of the lakes (12 out of 19) were undersaturated with CO2 during daytime. Surface water pCO2 varied from 26 to 4600 ppm. Using estimates of gas transfer velocity from two different methods, we found the average daytime flux of CO2 in these lakes to vary from -3.11 mg C m-2d-1 to 36 mg C m-2 d-1. Weighted-averages of pCO2 and flux using lake area were 692 ppm and 2.33 mg C m-2 d-1, respectively. However, these values were dominated by one large coastal lake that was saturated with CO2. The other 18 lakes yielded averages pCO2 and flux of 282 ppm and -0.65 mg C m-2 d-1. Eutrophication is one the biggest contemporary threats to the global freshwater supply, and is particularly severe in developing countries. This study, despite its limited scope, provides strong support to the fact that eutrophic lakes may act as CO2 sinks rather than sources. Follow-up studies on the diurnal and seasonal pCO2 trends and the metabolic characteristics of these lakes will reveal the determinants of their carbon metabolism.

  8. Variability of wet troposphere delays over inland reservoirs as simulated by a high-resolution regional climate model

    NASA Astrophysics Data System (ADS)

    Clark, E.; Lettenmaier, D. P.

    2014-12-01

    Satellite radar altimetry is widely used for measuring global sea level variations and, increasingly, water height variations of inland water bodies. Existing satellite radar altimeters measure water surfaces directly below the spacecraft (approximately at nadir). Over the ocean, most of these satellites use radiometry to measure the delay of radar signals caused by water vapor in the atmosphere (also known as the wet troposphere delay (WTD)). However, radiometry can only be used to estimate this delay over the largest inland water bodies, such as the Great Lakes, due to spatial resolution issues. As a result, atmospheric models are typically used to simulate and correct for the WTD at the time of observations. The resolutions of these models are quite coarse, at best about 5000 km2 at 30˚N. The upcoming NASA- and CNES-led Surface Water and Ocean Topography (SWOT) mission, on the other hand, will use interferometric synthetic aperture radar (InSAR) techniques to measure a 120-km-wide swath of the Earth's surface. SWOT is expected to make useful measurements of water surface elevation and extent (and storage change) for inland water bodies at spatial scales as small as 250 m, which is much smaller than current altimetry targets and several orders of magnitude smaller than the models used for wet troposphere corrections. Here, we calculate WTD from very high-resolution (4/3-km to 4-km) simulations of the Weather Research and Forecasting (WRF) regional climate model, and use the results to evaluate spatial variations in WTD. We focus on six U.S. reservoirs: Lake Elwell (MT), Lake Pend Oreille (ID), Upper Klamath Lake (OR), Elephant Butte (NM), Ray Hubbard (TX), and Sam Rayburn (TX). The reservoirs vary in climate, shape, use, and size. Because evaporation from open water impacts local water vapor content, we compare time series of WTD over land and water in the vicinity of each reservoir. To account for resolution effects, we examine the difference in WRF

  9. Metagenomics Reveals a Novel Virophage Population in a Tibetan Mountain Lake

    PubMed Central

    Oh, Seungdae; Yoo, Dongwan; Liu, Wen-Tso

    2016-01-01

    Virophages are parasites of giant viruses that infect eukaryotic organisms and may affect the ecology of inland water ecosystems. Despite the potential ecological impact, limited information is available on the distribution, diversity, and hosts of virophages in ecosystems. Metagenomics revealed that virophages were widely distributed in inland waters with various environmental characteristics including salinity and nutrient availability. A novel virophage population was overrepresented in a planktonic microbial community of the Tibetan mountain lake, Lake Qinghai. Our study identified coccolithophores and coccolithovirus-like phycodnaviruses in the same community, which may serve as eukaryotic and viral hosts of the virophage population, respectively. PMID:27151658

  10. 78 FR 23849 - Inland Waterways Navigation Regulation: Sacramento River, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-23

    ... comments in response, therefore, the rule will go into effect as scheduled. DATES: The effective date of the direct final rule published January 23, 2013 (78 FR 4785) is confirmed as April 23, 2013. FOR... entitled, ``Inland Waterways Navigation Regulation: Sacramento River, CA'' in the Federal Register (78...

  11. 75 FR 78688 - Inland Waterways Users Board; Request for Nominations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-16

    ... FR 7620), on July 11, 2008 (73 FR 39952), on February 24, 2009 (74 FR 8236) and the notice published on February 4, 2010 (75 FR 5769) have been retained for consideration. Renomination is not required... Department of the Army Inland Waterways Users Board; Request for Nominations AGENCY: Department of the...

  12. 33 CFR 62.32 - Inland waters obstruction mark.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Inland waters obstruction mark. 62.32 Section 62.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System §...

  13. 33 CFR 62.32 - Inland waters obstruction mark.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Inland waters obstruction mark. 62.32 Section 62.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System §...

  14. 33 CFR 62.32 - Inland waters obstruction mark.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Inland waters obstruction mark. 62.32 Section 62.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System §...

  15. 33 CFR 62.32 - Inland waters obstruction mark.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Inland waters obstruction mark. 62.32 Section 62.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System §...

  16. 33 CFR 62.32 - Inland waters obstruction mark.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Inland waters obstruction mark. 62.32 Section 62.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System §...

  17. 77 FR 52175 - Changes to the Inland Navigation Rules

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-28

    ... Act notice regarding our public dockets in the January 17, 2008, issue of the Federal Register (73 FR... Secretary to move the inland navigation rules from the United States Code (U.S.C.) to 33 CFR part 83. 75 FR... prototype testing, feasibility studies, and other limited activities. However, the specific...

  18. Aquatic community response in a groundwater-fed desert lake to Holocene desiccation of the Sahara

    NASA Astrophysics Data System (ADS)

    Eggermont, Hilde; Verschuren, Dirk; Fagot, Maureen; Rumes, Bob; Van Bocxlaer, Bert; Kröpelin, Stefan

    2008-12-01

    The finely laminated sediment record of a permanent, hypersaline, desert oasis lake in the Ounianga region of northeastern Chad presents a unique opportunity to document the hydrological evolution of this groundwater-fed aquatic ecosystem during mid- and late-Holocene desiccation of the Sahara. In this study we reconstruct long-term changes in zoobenthos and zooplankton communities of Lake Yoa as their early-Holocene freshwater habitat changed into the hypersaline conditions prevailing today. Chironomid production peaked during the fresh-to-saline transition period, then stabilized at about half that of the earlier freshwater ecosystem. Quantitative salinity inferences based on fossil chironomid assemblages indicate that the fresh-to-saline transition occurred fairly abruptly between ˜4100 and 3400 cal yr BP, but that the ecosystem was buffered against shorter-term climate fluctuations due to continuous inflow of fossil groundwater. The mixture of tropical-African and southern Palaearctic chironomid faunas in the Lake Yoa fossil record required us to address several methodological issues concerning chironomid-based salinity reconstruction, and the applicability of a calibration dataset based on tropical East and West African lakes to this Sahara desert locality. The most coherent reconstruction was obtained with an inference model that applies a weighted best-modern-analogue (WMAT) transfer function to the African calibration dataset expanded with six Sahara lakes.

  19. De novo sequences of Haloquadratum walsbyi from Lake Tyrrell, Australia, reveal a variable genomic landscape.

    PubMed

    Tully, Benjamin J; Emerson, Joanne B; Andrade, Karen; Brocks, Jochen J; Allen, Eric E; Banfield, Jillian F; Heidelberg, Karla B

    2015-01-01

    Hypersaline systems near salt saturation levels represent an extreme environment, in which organisms grow and survive near the limits of life. One of the abundant members of the microbial communities in hypersaline systems is the square archaeon, Haloquadratum walsbyi. Utilizing a short-read metagenome from Lake Tyrrell, a hypersaline ecosystem in Victoria, Australia, we performed a comparative genomic analysis of H. walsbyi to better understand the extent of variation between strains/subspecies. Results revealed that previously isolated strains/subspecies do not fully describe the complete repertoire of the genomic landscape present in H. walsbyi. Rearrangements, insertions, and deletions were observed for the Lake Tyrrell derived Haloquadratum genomes and were supported by environmental de novo sequences, including shifts in the dominant genomic landscape of the two most abundant strains. Analysis pertaining to halomucins indicated that homologs for this large protein are not a feature common for all species of Haloquadratum. Further, we analyzed ATP-binding cassette transporters (ABC-type transporters) for evidence of niche partitioning between different strains/subspecies. We were able to identify unique and variable transporter subunits from all five genomes analyzed and the de novo environmental sequences, suggesting that differences in nutrient and carbon source acquisition may play a role in maintaining distinct strains/subspecies.

  20. Does an ionospheric hole appear after an inland earthquake?

    NASA Astrophysics Data System (ADS)

    Kamogawa, Masashi; Kanaya, Tatsuya; Orihara, Yoshiaki; Toyoda, Atsushi; Suzuki, Yuko; Togo, Shoho; Liu, Jann-Yenq

    2015-11-01

    Ionospheric disturbances occurred as a result of the tsunami associated with the 2011 M9.0 off the Pacific Coast of the Tohoku earthquake (EQ). The ionospheric disturbances propagated radially from the tsunami source area, termed the traveling ionospheric disturbance. In addition to the traveling ionospheric disturbance, an ionospheric plasma depression lasting for approximately 1 h occurred above the tsunami source area, called a tsunami ionospheric hole. In this study, we compare the ionospheric disturbances caused by large inland and submarine EQs to investigate whether an ionospheric plasma depression only occurs in association with a tsunami. Note that we term an EQ with a tsunami a submarine EQ. To investigate the presence of a plasma depression, i.e., an ionospheric hole, associated with an inland EQ, data on total electron content between the global positioning system satellite and its receivers were used. Comparison of two inland and two submarine EQ events with similar magnitudes around 7 showed that ionospheric holes were observed only for the submarine EQs. This discrepancy might be attributed to the different excitation amplitudes of the atmospheric acoustic waves between the unidirectional fault displacement and the tsunami uplift/depression, corresponding to quarter and one-period variations. From this hypothesis, we predicted that an ionospheric hole could be observed after a significantly large inland EQ with a sufficiently large vertical ground displacement. In fact, we recognized the ionospheric hole generated by the large inland EQ that recently occurred in the Nepal with the magnitude of 7.8 on 25 April 2015.

  1. Mesoscale Modeling of the Inland Nocturnal Sea Breeze

    SciTech Connect

    Kurzeja, R.J.; Buckley, R.L.

    1995-09-12

    The mesoscale sea breeze has important consequences for many densely populated coastal environments, including convection initiation, aviation safety, and air quality. The sea breeze characteristics before and after sunset are markedly different (Sha et al 1993). A gravity current will form during the early afternoon due to the relatively large density difference between the land and sea air. During the afternoon, as the lighter land air is forced upward by the cooler dense sea air, Kelvin-Helmholtz (KH) billows often form along the interface, as well as thin regions of turbulent rising air, playing a crucial role in the mixing process (Simpson 1994). After sunset, the frontal zone expands as longwave radiation cools the surface which reduces vertical mixing. With further inland penetration, the sea breeze encounters increasingly stable air near the ground, resulting in the formation of an undular bore or cutoff vortex (Sha et al. 1993). It has been demonstrated that large-scale winds have profound effects on both the strength and inland penetration of sea breezes (Arritt 1993, among others). In general, offshore flow results in a sharper frontal discontinuity and less inland penetration, while onshore flow produces weaker fronts which may penetrate further inland. Most sea breeze studies have focused on its more dramatic daytime properties near the coast whereas inland nocturnal sea breezes have received much less attention. The reason for this neglect is a lack of good observational data in the boundary layer. Sha et al. (1991) note the necessity of high resolution data to capture the finer structures of the sea breeze. A unique opportunity to examine the nocturnal sea breeze became available at the Savannah River Site (SRS, located roughly 150 km from the Atlantic Ocean in southwestern South Carolina) during the Stable Boundary Layer Experiment (STABLE), 12-17 April, 1988. (Abstract Truncated)

  2. 48 CFR 47.303-10 - F.o.b. inland carrier, point of exportation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false F.o.b. inland carrier... ACQUISITION REGULATION CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 47.303-10 F.o.b. inland carrier, point of exportation. (a) Explanation of delivery term. F.o.b. inland carrier, point...

  3. 48 CFR 52.247-39 - F.o.b. Inland Point, Country of Importation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false F.o.b. Inland Point... Provisions and Clauses 52.247-39 F.o.b. Inland Point, Country of Importation. As prescribed in 47.303-11(c), insert the following clause in solicitations and contracts when the delivery term is f.o.b. inland...

  4. 48 CFR 47.303-11 - F.o.b. inland point, country of importation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false F.o.b. inland point... ACQUISITION REGULATION CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 47.303-11 F.o.b. inland point, country of importation. (a) Explanation of delivery term. F.o.b. inland point, country...

  5. Bacterial Communities of Three Saline Meromictic Lakes in Central Asia

    PubMed Central

    Baatar, Bayanmunkh; Chiang, Pei-Wen; Rogozin, Denis Yu; Wu, Yu-Ting; Tseng, Ching-Hung; Yang, Cheng-Yu; Chiu, Hsiu-Hui; Oyuntsetseg, Bolormaa; Degermendzhy, Andrey G.; Tang, Sen-Lin

    2016-01-01

    Meromictic lakes located in landlocked steppes of central Asia (~2500 km inland) have unique geophysiochemical characteristics compared to other meromictic lakes. To characterize their bacteria and elucidate relationships between those bacteria and surrounding environments, water samples were collected from three saline meromictic lakes (Lakes Shira, Shunet and Oigon) in the border between Siberia and the West Mongolia, near the center of Asia. Based on in-depth tag pyrosequencing, bacterial communities were highly variable and dissimilar among lakes and between oxic and anoxic layers within individual lakes. Proteobacteria, Bacteroidetes, Cyanobacteria, Actinobacteria and Firmicutes were the most abundant phyla, whereas three genera of purple sulfur bacteria (a novel genus, Thiocapsa and Halochromatium) were predominant bacterial components in the anoxic layer of Lake Shira (~20.6% of relative abundance), Lake Shunet (~27.1%) and Lake Oigon (~9.25%), respectively. However, few known green sulfur bacteria were detected. Notably, 3.94% of all sequencing reads were classified into 19 candidate divisions, which was especially high (23.12%) in the anoxic layer of Lake Shunet. Furthermore, several hydro-parameters (temperature, pH, dissolved oxygen, H2S and salinity) were associated (P< 0.05) with variations in dominant bacterial groups. In conclusion, based on highly variable bacterial composition in water layers or lakes, we inferred that the meromictic ecosystem was characterized by high diversity and heterogenous niches. PMID:26934492

  6. Aerobic organic carbon mineralization by sulfate-reducing bacteria in the oxygen-saturated photic zone of a hypersaline microbial mat.

    PubMed

    Jonkers, H M; Koh, I-O; Behrend, P; Muyzer, G; de Beer, D

    2005-02-01

    The sulfate-reducing bacterium strain SRB D2 isolated from the photic zone of a hypersaline microbial mat, from Lake Chiprana, NE Spain, respired pyruvate, alanine, and alpha-ketoglutarate but not formate, lactate, malate, succinate, and serine at significant rates under fully oxic conditions. Dehydrogenase enzymes of only the former substrates are likely oxygen-tolerant as all substrates supported anaerobic sulfate reduction. No indications were found, however, that aerobic respiration supported growth. Although strain SRB D2 appeared phylogenetically closely related to the oxygen-tolerant sulfate-reducing bacterium Desulfovibrio oxyclinae, substrate spectra were markedly different. Most-probable-number (MPN) estimates of sulfate-reducing bacteria and aerobic heterotrophic bacteria indicated that the latter were numerically dominant in both the photic and aphotic zones of the mat. Moreover, substrate spectra of representative isolates showed that the aerobic heterotrophic bacteria are metabolically more diverse. These findings indicate that sulfate-reducing bacteria in the fully oxic photic zone of mats have to compete with aerobic heterotrophic bacteria for organic substrates. Porewater analysis revealed that total carbohydrates and low-molecular-weight carbon compounds (LMWC) made up substantial fractions of the total dissolved organic carbon (DOC) pool and that nighttime degradation of the former was concomitant with increased concentration of the latter. Our findings indicate that aerobic respiration by sulfate-reducing bacteria contributes to organic carbon mineralization in the oxic zone of microbial mats as daytime porewater LMWC concentrations are above typical half-saturation constants.

  7. Aerobic organic carbon mineralization by sulfate-reducing bacteria in the oxygen-saturated photic zone of a hypersaline microbial mat.

    PubMed

    Jonkers, H M; Koh, I-O; Behrend, P; Muyzer, G; de Beer, D

    2005-02-01

    The sulfate-reducing bacterium strain SRB D2 isolated from the photic zone of a hypersaline microbial mat, from Lake Chiprana, NE Spain, respired pyruvate, alanine, and alpha-ketoglutarate but not formate, lactate, malate, succinate, and serine at significant rates under fully oxic conditions. Dehydrogenase enzymes of only the former substrates are likely oxygen-tolerant as all substrates supported anaerobic sulfate reduction. No indications were found, however, that aerobic respiration supported growth. Although strain SRB D2 appeared phylogenetically closely related to the oxygen-tolerant sulfate-reducing bacterium Desulfovibrio oxyclinae, substrate spectra were markedly different. Most-probable-number (MPN) estimates of sulfate-reducing bacteria and aerobic heterotrophic bacteria indicated that the latter were numerically dominant in both the photic and aphotic zones of the mat. Moreover, substrate spectra of representative isolates showed that the aerobic heterotrophic bacteria are metabolically more diverse. These findings indicate that sulfate-reducing bacteria in the fully oxic photic zone of mats have to compete with aerobic heterotrophic bacteria for organic substrates. Porewater analysis revealed that total carbohydrates and low-molecular-weight carbon compounds (LMWC) made up substantial fractions of the total dissolved organic carbon (DOC) pool and that nighttime degradation of the former was concomitant with increased concentration of the latter. Our findings indicate that aerobic respiration by sulfate-reducing bacteria contributes to organic carbon mineralization in the oxic zone of microbial mats as daytime porewater LMWC concentrations are above typical half-saturation constants. PMID:15965719

  8. Prokaryotic diversity in one of the largest hypersaline coastal lagoons in the world.

    PubMed

    Clementino, M M; Vieira, R P; Cardoso, A M; Nascimento, A P A; Silveira, C B; Riva, T C; Gonzalez, A S M; Paranhos, R; Albano, R M; Ventosa, A; Martins, O B

    2008-07-01

    Araruama Lagoon is an environment characterized by high salt concentrations. The low raining and high evaporation rates in this region favored the development of many salty ponds around the lagoon. In order to reveal the microbial composition of this system, we performed a 16S rRNA gene survey. Among archaea, most clones were related to uncultured environmental Euryarchaeota. In lagoon water, we found some clones related to Methanomicrobia and Methanothermococcus groups, while in the saline pond water members related to the genus Haloarcula were detected. Bacterial community was dominated by clones related to Gamma-proteobacteria, Actinobacteria, and Synechococcus in lagoon water, while Salinibacter ruber relatives dominated in saline pond. We also detected the presence of Alpha-proteobacteria, Pseudomonas-like bacteria and Verrucomicrobia. Only representatives of the genus Ralstonia were cosmopolitan, being observed in both systems. The detection of a substantial number of clones related to uncultured archaea and bacteria suggest that the hypersaline waters of Araruama harbor a pool of novel prokaryotic phylotypes, distinct from those observed in other similar systems. We also observed clones related to halophilic genera of cyanobacteria that are specific for each habitat studied. Additionally, two bacterioplankton molecular markers with ecological relevance were analyzed, one is linked to nitrogen fixation (nifH) and the other is linked to carbon fixation by bacterial photosynthesis, the protochlorophyllide genes, revealing a specific genetic distribution in this ecosystem. This is the first study of the biogeography and community structure of microbial assemblages in Brazilian tropical hypersaline environments. This work is directed towards a better understanding of the free-living prokaryotic diversity adapted to life in hypersaline waters.

  9. Linking Archaeal Molecular Diversity and Lipid Biomarker Composition in a Hypersaline Microbial Mat Community

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda; Orphan, Victoria; Turk, Kendra; Embaye, Tsegereda; Kubo, Mike; Summons, Roger

    2005-01-01

    Lipid biomarkers for discrete microbial groups are a valuable tool for establishing links to ancient microbial ecosystems. Lipid biomarkers can establish organism source and function in contemporary microbial ecosystems (membrane lipids) and by analogy, potential relevance to the fossilized carbon skeletons (geolipids) extracted from ancient sedimentary rock. The Mars Exploration Rovers have provided clear evidence for an early wet Mars and the presence of hypersaline evaporitic basins. Ongoing work on an early Earth analog, the hypersaline benthic mats in Guerrero Negro, Baja California Sur, may provide clues to what may have evolved and flourished on an early wet Mars, if only for a short period. Cyanobacterial mats are a pertinent early Earth analog for consideration of evolutionary and microbial processes within the aerobic photosynthetic and adjacent anoxic layers. Fluctuations in physio-chemical parameters associated with spatial and temporal scales are expressed through vast microbial metabolic diversity. Our recent work hopes to establish the dynamic of archaeal diversity, particularly as it relates to methane production in this high sulfate environment, through the use of lipid biomarker and phylogenetic analyses. Archaeal 16s rRNA and mcrA gene assemblages, demonstrated distinct spatial separation over the 130 mm core of at least three distinct genera within the order Methanosarcinales, as well as an abundance of uncultured members of the Thermoplasmales and Crenarchaeota. Ether-bound lipid analysis identified abundant 0-alkyl and 0-isopranyl chains throughout the core, and the presence of sn-2 hydroxyarchaeol, a biomarker for methylotrophic methanogens. A unique ether isoprenoid chain, a C30:1 , possibly related to the geolipid squalane, a paleobiomarker associated with hypersaline environments, was most abundant within the oxic-anoxic transition zone.

  10. Bacterial Community Response to Petroleum Hydrocarbon Amendments in Freshwater, Marine, and Hypersaline Water-Containing Microcosms

    PubMed Central

    Jurelevicius, Diogo; Alvarez, Vanessa Marques; Marques, Joana Montezano; de Sousa Lima, Laryssa Ribeiro Fonseca; Dias, Felipe de Almeida

    2013-01-01

    Hydrocarbon-degrading bacterial communities from freshwater, marine, and hypersaline Brazilian aquatic ecosystems (with water salinities corresponding to 0.2%, 4%, and 5%, respectively) were enriched with different hydrocarbons (heptadecane, naphthalene, or crude oil). Changes within the different microcosms of bacterial communities were analyzed using cultivation approaches and molecular methods (DNA and RNA extraction, followed by genetic fingerprinting and analyses of clone libraries based on the 16S rRNA-coding gene). A redundancy analysis (RDA) of the genetic fingerprint data and a principal component analysis (PCA) of the clone libraries revealed hydrocarbon-enriched bacterial communities specific for each ecosystem studied. However, within the same ecosystem, different bacterial communities were selected according to the petroleum hydrocarbon used. In general, the results demonstrated that Acinetobacter and Cloacibacterium were the dominant genera in freshwater microcosms; the Oceanospirillales order and the Marinobacter, Pseudomonas, and Cycloclasticus genera predominated in marine microcosms; and the Oceanospirillales order and the Marinobacter genus were selected in the different hydrocarbon-containing microcosms in hypersaline water. Determination of total petroleum hydrocarbons (TPHs) in all microcosms after 32 days of incubation showed a decrease in the hydrocarbon concentration compared to that for the controls. A total of 50 (41.3%) isolates from the different hydrocarbon-contaminated microcosms were associated with the dominant operational taxonomic units (OTUs) obtained from the clone libraries, and their growth in the hydrocarbon contaminating the microcosm from which they were isolated as the sole carbon source was observed. These data provide insight into the general response of bacterial communities from freshwater, marine, and hypersaline aquatic ecosystems to petroleum hydrocarbon contamination. PMID:23872573

  11. Anaerobic oxidation of methane by sulfate in hypersaline groundwater of the Dead Sea aquifer

    PubMed Central

    Avrahamov, N; Antler, G; Yechieli, Y; Gavrieli, I; Joye, S B; Saxton, M; Turchyn, A V; Sivan, O

    2014-01-01

    Geochemical and microbial evidence points to anaerobic oxidation of methane (AOM) likely coupled with bacterial sulfate reduction in the hypersaline groundwater of the Dead Sea (DS) alluvial aquifer. Groundwater was sampled from nine boreholes drilled along the Arugot alluvial fan next to the DS. The groundwater samples were highly saline (up to 6300 mm chlorine), anoxic, and contained methane. A mass balance calculation demonstrates that the very low δ13CDIC in this groundwater is due to anaerobic methane oxidation. Sulfate depletion coincident with isotope enrichment of sulfur and oxygen isotopes in the sulfate suggests that sulfate reduction is associated with this AOM. DNA extraction and 16S amplicon sequencing were used to explore the microbial community present and were found to be microbial composition indicative of bacterial sulfate reducers associated with anaerobic methanotrophic archaea (ANME) driving AOM. The net sulfate reduction seems to be primarily controlled by the salinity and the available methane and is substantially lower as salinity increases (2.5 mm sulfate removal at 3000 mm chlorine but only 0.5 mm sulfate removal at 6300 mm chlorine). Low overall sulfur isotope fractionation observed (34ε = 17 ± 3.5‰) hints at high rates of sulfate reduction, as has been previously suggested for sulfate reduction coupled with methane oxidation. The new results demonstrate the presence of sulfate-driven AOM in terrestrial hypersaline systems and expand our understanding of how microbial life is sustained under the challenging conditions of an extremely hypersaline environment. PMID:25039851

  12. Hydrology and Salt Balance in a Large, Hypersaline Coastal Lagoon: Lagoa de Araruama, Brazil

    NASA Astrophysics Data System (ADS)

    Kjerfve, Björn; Schettini, C. A. F.; Knoppers, Bastiaan; Lessa, Guilherme; Ferreira, H. O.

    1996-06-01

    Lagoa de Araruama in the state of Rio de Janeiro, Brazil, is a hypersaline coastal lagoon as a result of semi-arid climate conditions, a small drainage basin and a choked entrance channel. The lagoon has been continuously hypersaline for at least 4·5 centuries, but the mean salinity has varied substantially. It has recently decreased from 57 to 52 as indicated by density (salinity) measurements between 1965 and 1990. Analysis of more than 20 years of salinity time series data, in addition to monthly lagoon cruises to measure the spatial salinity distribution, indicate that the lagoon salinity largely fluctuates in response to the difference between evaporation and precipitation. The major factor explaining the long-term trend of decreasing salinity in the lagoon is the constant pumping of 1 m 3s -1of freshwater to the communities surrounding the lagoon from an adjacent watershed, and subsequent discharge of this water into Lagoa de Araruama. The net salt budget is primarily a balance between the advective import of salt from the coastal ocean and eddy diffusive export of salt to the ocean, although the extensive mining of salt from the lagoon during past decades is also a small but significant contribution to the salt budget. The flushing half-life is proposed as a useful time scale of water exchange, is calculated based on a combination of hydrological and tidal processes, and is excellent for comparison of lagoons and assessing water quality changes. The flushing half-life measures 83·5 days for Lagoa de Araruama, considerably longer than for most other coastal lagoons. The proposed dredging of a second ocean channel to Lagoa de Araruama is probably not a good idea. It is likely to accelerate the decrease of lagoon salinity and somewhat improve the lagoon water exchange. At the same time, this will eliminate the apparent buffering capacity provided by the hypersaline environment, and thus may potentially cause water quality problems.

  13. Bacterial community response to petroleum hydrocarbon amendments in freshwater, marine, and hypersaline water-containing microcosms.

    PubMed

    Jurelevicius, Diogo; Alvarez, Vanessa Marques; Marques, Joana Montezano; de Sousa Lima, Laryssa Ribeiro Fonseca; Dias, Felipe de Almeida; Seldin, Lucy

    2013-10-01

    Hydrocarbon-degrading bacterial communities from freshwater, marine, and hypersaline Brazilian aquatic ecosystems (with water salinities corresponding to 0.2%, 4%, and 5%, respectively) were enriched with different hydrocarbons (heptadecane, naphthalene, or crude oil). Changes within the different microcosms of bacterial communities were analyzed using cultivation approaches and molecular methods (DNA and RNA extraction, followed by genetic fingerprinting and analyses of clone libraries based on the 16S rRNA-coding gene). A redundancy analysis (RDA) of the genetic fingerprint data and a principal component analysis (PCA) of the clone libraries revealed hydrocarbon-enriched bacterial communities specific for each ecosystem studied. However, within the same ecosystem, different bacterial communities were selected according to the petroleum hydrocarbon used. In general, the results demonstrated that Acinetobacter and Cloacibacterium were the dominant genera in freshwater microcosms; the Oceanospirillales order and the Marinobacter, Pseudomonas, and Cycloclasticus genera predominated in marine microcosms; and the Oceanospirillales order and the Marinobacter genus were selected in the different hydrocarbon-containing microcosms in hypersaline water. Determination of total petroleum hydrocarbons (TPHs) in all microcosms after 32 days of incubation showed a decrease in the hydrocarbon concentration compared to that for the controls. A total of 50 (41.3%) isolates from the different hydrocarbon-contaminated microcosms were associated with the dominant operational taxonomic units (OTUs) obtained from the clone libraries, and their growth in the hydrocarbon contaminating the microcosm from which they were isolated as the sole carbon source was observed. These data provide insight into the general response of bacterial communities from freshwater, marine, and hypersaline aquatic ecosystems to petroleum hydrocarbon contamination.

  14. Response of biotic communities to salinity changes in a Mediterranean hypersaline stream

    PubMed Central

    Velasco, Josefa; Millán, Andrés; Hernández, Juan; Gutiérrez, Cayetano; Abellán, Pedro; Sánchez, David; Ruiz, Mar

    2006-01-01

    Background This study investigates the relationship between salinity and biotic communities (primary producers and macroinvertebrates) in Rambla Salada, a Mediterranean hypersaline stream in SE Spain. Since the 1980's, the mean salinity of the stream has fallen from about 100 g L-1 to 35.5 g L-1, due to intensive irrigated agriculture in the watershed. Furthermore, large dilutions occur occasionally when the water irrigation channel suffers cracks. Results Along the salinity gradient studied (3.5 – 76.4 g L-1) Cladophora glomerata and Ruppia maritima biomass decreased with increasing salinity, while the biomass of epipelic algae increased. Diptera and Coleoptera species dominated the community both in disturbed as in re-established conditions. Most macroinvertebrates species found in Rambla Salada stream are euryhaline species with a broad range of salinity tolerance. Eight of them were recorded in natural hypersaline conditions (~100 g L-1) prior to important change in land use of the watershed: Ephydra flavipes, Stratyomis longicornis, Nebrioporus ceresyi, N. baeticus, Berosus hispanicus, Enochrus falcarius, Ochthebius cuprescens and Sigara selecta. However, other species recorded in the past, such as Ochthebius glaber, O. notabilis and Enochrus politus, were restricted to a hypersaline source or absent from Rambla Salada. The dilution of salinity to 3.5 – 6.8 gL-1 allowed the colonization of species with low salininty tolerance, such as Melanopsis praemorsa, Anax sp., Simulidae, Ceratopogonidae and Tanypodinae. The abundance of Ephydra flavipes and Ochthebius corrugatus showed a positive significant response to salinity, while Anax sp., Simulidae, S. selecta, N. ceresyi, N. baeticus, and B. hispanicus showed significant negative correlations. The number of total macroinvertebrate taxa, Diptera and Coleoptera species, number of families, Margalef's index and Shannon's diversity index decreased with increasing salinity. However, the rest of community

  15. Patterns of Local Circulation in the Itaipu Lake Area: Numerical Simulations of Lake Breeze.

    NASA Astrophysics Data System (ADS)

    Stivari, Sônia M. S.; de Oliveira, Amauri P.; Karam, Hugo A.; Soares, Jacyra

    2003-01-01

    The lake-breeze circulation in the Itaipu region was investigated numerically using a nonhydrostatic version of the Topographic Vorticity Model. The area of study corresponds to a 100 km × 180 km rectangle, located on the Brazil-Paraguay border, with Itaipu Lake in its center. The characteristics of the lake breeze generated by the numerical experiments were consistent with the observations available in the area. The numerical experiments have shown that the land use effect is important in the spatial distribution of the lake-breeze circulation and that the topography contributes to modulating the breeze intensity, with the daytime valley-mountain circulation intensifying the lake breeze. However, the circulation pattern observed during daytime over the region is mainly due to the Itaipu Lake presence. The numerical results indicated that Itaipu Lake is able to generate and sustain a lake breeze, with 3.5 m s1 of maximum intensity and 1500-m depth, that propagates inland at 5.1 km h1 under typical undisturbed and calm-wind summer conditions.

  16. Limitations to lake trout (Salvelinus namaycush) rehabilitation in the Great Lakes imposed by biotic interactions occurring at early life stages

    USGS Publications Warehouse

    Jones, Michael L.; Eck, Gary W.; Evans, David O.; Fabrizio, Mary C.; Hoff, Michael H.; Hudson, Patrick L.; Janssen, John; Jude, David; O'Gorman, Robert; Savino, Jacqueline F.

    1995-01-01

    We examine evidence that biotic factors, particularly predation, may be limiting early survival of wild lake trout (Salvelinus namaycush) juveniles in many areas of the Great Lakes. The Great Lakes contain numerous potential predators of lake trout eggs and fry, some of which are recent invaders, and most of which were probably absent when lake trout most recently re-invaded the Great Lakes after the last ice age. Simple quantitative models of predation suggest that plausible assumptions about prey densities, predator feeding rates, and duration of exposure of predator to prey can lead to very high estimates of predation mortality, in some instances approaching 100%. Indirect evidence from inter-Great Lake comparisons and inland lake examples also suggest that biotic factors may impede successful lake trout colonization. Our synthesis of the evidence leads to recommendations for research to better define field feeding rates of lake trout egg and fry predators and comparative studies of densities of potential egg and fry predators on lake trout spawning reefs. Management options should be designed to provide useful information as well as achieve short-term goals. From a management standpoint we recommend that: newly constructed lake trout reefs should be placed well away from concentrations of potential predators; offshore spawning reefs should be stocked; salmonine stocking, nutrient abatement, and commercial harvest of alewives should all be considered as options to enhance survival of young lake trout; hatchery lake trout should not be stocked at sites where wild lake trout are showing signs of recovery; and exotic species expansions or introductions must be curtailed to maintain or improve on our recent successes in lake trout rehabilitation.

  17. Lake Eyre

    Atmospheric Science Data Center

    2013-04-16

    ...   View Larger Image Lake Eyre is a large salt lake situated between two deserts in one of Australia's driest regions. ... the effect of sunglint at the nadir camera view angle. Dry, salt encrusted parts of the lake appear bright white or gray. Purple areas have ...

  18. The Oligochaeta (Annelida, Clitellata) of the St. Lawrence Great Lakes region: An update

    USGS Publications Warehouse

    Spencer, Douglas R.; Hudson, Patrick L.

    2003-01-01

    An updated oligochaete species list for the Great Lakes region is provided. The list was developed through the reexamination of the taxa reported in a previous report in 1980, addition of new taxa or records collected from the region since 1980, and an update of taxonomy commensurate with systematic and nomenclatural changes over the intervening years since the last review. The authors found 74 papers mentioning Great Lakes oligochaete species. The majority of these papers were published in the 1980s. The literature review and additional collections resulted in 15 species being added to the previous list. Nine taxa were removed from the previous list due to misidentification, synonymies, level of identification, or inability to confirm the identity. Based on this review, 101 species of Oligochaeta are now known from the St. Lawrence Great Lakes watershed. Of these, 95 species are known from the St. Lawrence Great Lakes proper, with an additional 6 species recorded from the inland waters of the watershed. The greatest diversity of oligochaete species was found in the inland waters of the region (81) followed by Lake Huron (72), Lake Ontario (65), Lake Erie (64), Lake Superior (63), Lake Michigan (62), St. Marys River (60), Niagara River (49), Saginaw Bay (44), St. Clair River (37), Lake St. Clair (36), St. Lawrence River (27), and the Detroit River (21). Three species are suspected of being introduced, Branchiura sowerbyi, Gianius aquaedulcisand Ripistes parasita, and two are believed to be endemic, Thalassodrilus hallae andTeneridrilus flexus.

  19. Inland saltwater as a medium for the production of biomass

    SciTech Connect

    Brune, D.E.; Reach, C.D.; O'Connor, J.T.

    1981-01-01

    A study was undertaken to determine if waste brine waters originating from inland salt seeps and crude oil production could be used to sustain the growth of marine organisms. In spite of a chemical composition significantly different from seawater controls, a central Missouri brine supported the rapid and dense growth of marine algae, which, in turn, was found to promote the normal growth of the brine shrimp Artemia. Additional experiments with oil-field brines indicated that the ability of waste brines to sustain algae-shrimp growth is site specific. The experimental results indicate that oil-field brines and inland salt waters can serve as media for the production of marine plants and animals.

  20. Assessment of temporal variations of water quality in inland water bodies using atmospheric corrected satellite remotely sensed image data.

    PubMed

    Hadjimitsis, Diofantos G; Clayton, Chris

    2009-12-01

    Although there have been many studies conducted on the use of satellite remote sensing for water quality monitoring and assessment in inland water bodies, relatively few studies have considered the problem of atmospheric intervention of the satellite signal. The problem is especially significant when using time series multi-spectral satellite data to monitor water quality surveillance in inland waters such as reservoirs, lakes, and dams because atmospheric effects constitute the majority of the at-satellite reflectance over water. For the assessment of temporal variations of water quality, the use of multi-date satellite images is required so atmospheric corrected image data must be determined. The aim of this study is to provide a simple way of monitoring and assessing temporal variations of water quality in a set of inland water bodies using an earth observation- based approach. The proposed methodology is based on the development of an image-based algorithm which consists of a selection of sampling area on the image (outlet), application of masking and convolution image processing filter, and application of the darkest pixel atmospheric correction. The proposed method has been applied in two different geographical areas, in UK and Cyprus. Mainly, the method has been applied to a series of eight archived Landsat-5 TM images acquired from March 1985 up to November 1985 of the Lower Thames Valley area in the West London (UK) consisting of large water treatment reservoirs. Finally, the method is further tested to the Kourris Dam in Cyprus. It has been found that atmospheric correction is essential in water quality assessment studies using satellite remotely sensed imagery since it improves significantly the water reflectance enabling effective water quality assessment to be made.

  1. Characterization of SAR Mode Altimetry over Inland Water

    NASA Astrophysics Data System (ADS)

    Fabry, Pierre; Bercher, Nicolas

    2015-12-01

    Radar altimetry over the inland water domain is a difficult topic that still requires a lot of human expertise as well as manual editing and verifications. This is mainly due to the fact that inland water scenes are highly variable, both in space and time, which leads to a much broader range of radar signatures than in oceanography. The remark is particularly true for LRM altimetry and remains valid in many cases in SAR mode (SARM). In preparation for the operational Sentinel-3 mission and to better benefit from the improved SARM along-track resolution it is required to: 1. better characterize the SARM Individual Echoes, Multi-Look Stacks, 20Hz waveforms as well as the Range Integrated Power (RIP) over the inland water domain, 2. step toward processing schemes that account for the actual content of the illuminated scene. In this work, we introduce an automated technique to assess the water fraction within the Beam-limited Doppler footprint through its intersection area of with a water mask. This framework opens up new ways toward the automated characterization and processing of altimetry data based on regularly updated water masks.

  2. Atmospheric stability comparisons at shore and inland sites

    SciTech Connect

    Brown, R.M.; SethuRaman, S.; Nagle, C.

    1980-01-01

    The values needed to predict diffusion and resulting concentrations from sources near coastlines is limited by lack of experimental data at coastal locations. The results obtained in this study are directed to assist in those calculations. Wind measurements made at the coastal site and some comparisons with the measurements made at an inland location, both on Long Island, are presented. Continuous wind speed and direction measurements have been made at the Tiana Beach site since 1975. Hourly averaged wind direction, speed and gustiness types were obtained from these records, and processed by computer techniques. Simultaneous data from the inland location were also obtained. The data were grouped with a digital computer according to gustiness types, wind-speed categories and 10/sup 0/ wind direction increments from 0 to 360 degrees. The initial analysis was to separate the various gustiness types by the number of occurrences per month at each location. These data were used to determine the ratio of each type to the total monthly hours at each place. The ratios at each location were compared to give some understanding of the differences of total gustiness between the coastal and inland site.

  3. Digital waterway construction based on inland electronic navigation chart

    NASA Astrophysics Data System (ADS)

    Wang, Xue; Pan, Junfeng; Zhu, Weiwei

    2015-12-01

    With advantages of large capacity, long distance, low energy consumption, low cost, less land occupation and light pollution, inland waterway transportation becomes one of the most important constituents of the comprehensive transportation system and comprehensive water resources utilization in China. As one of "three elements" of navigation, waterway is the important basis for the development of water transportation and plays a key supporting role in shipping economic. The paper discuss how to realize the informatization and digitization of waterway management based on constructing an integrated system of standard inland electronic navigation chart production, waterway maintenance, navigation mark remote sensing and control, ship dynamic management, and water level remote sensing and report, which can also be the foundation of the intelligent waterway construction. Digital waterway construction is an information project and also has a practical meaning for waterway. It can not only meet the growing high assurance and security requirements for waterway, but also play a significant advantage in improving transport efficiency, reducing costs, promoting energy conservation and so on. This study lays a solid foundation on realizing intelligent waterway and building a smooth, efficient, safe, green modern inland waterway system, and must be considered as an unavoidable problem for the coordinated development between "low carbon" transportation and social economic.

  4. Evolution of genomic diversity and sex at extreme environments: Fungal life under hypersaline Dead Sea stress

    PubMed Central

    Kis-Papo, Tamar; Kirzhner, Valery; Wasser, Solomon P.; Nevo, Eviatar

    2003-01-01

    We have found that genomic diversity is generally positively correlated with abiotic and biotic stress levels (1–3). However, beyond a high-threshold level of stress, the diversity declines to a few adapted genotypes. The Dead Sea is the harshest planetary hypersaline environment (340 g·liter–1 total dissolved salts, ≈10 times sea water). Hence, the Dead Sea is an excellent natural laboratory for testing the “rise and fall” pattern of genetic diversity with stress proposed in this article. Here, we examined genomic diversity of the ascomycete fungus Aspergillus versicolor from saline, nonsaline, and hypersaline Dead Sea environments. We screened the coding and noncoding genomes of A. versicolor isolates by using >600 AFLP (amplified fragment length polymorphism) markers (equal to loci). Genomic diversity was positively correlated with stress, culminating in the Dead Sea surface but dropped drastically in 50- to 280-m-deep seawater. The genomic diversity pattern paralleled the pattern of sexual reproduction of fungal species across the same southward gradient of increasing stress in Israel. This parallel may suggest that diversity and sex are intertwined intimately according to the rise and fall pattern and adaptively selected by natural selection in fungal genome evolution. Future large-scale verification in micromycetes will define further the trajectories of diversity and sex in the rise and fall pattern. PMID:14645702

  5. Mollusc-Microbe Mutualisms Extend the Potential for Life in Hypersaline Systems

    NASA Astrophysics Data System (ADS)

    Hickman, Carole S.

    2003-11-01

    Metazoans in extreme environments have evolved mutualisms with microbes that extend the physical and chemical capabilities of both partners. Some of the best examples are bivalve molluscs in evaporite and hypersaline settings. Mollusc tissue is developmentally and evolutionarily amenable to housing vast numbers of symbiotic microbes. Documented benefits to the host are nutritional. Multiple postulated benefits to the microbes are related to optimizing metabolic performance at interfaces, where heterogeneity and steep gradients that cannot be negotiated by microbes can be spanned by larger metazoan hosts. A small cockle, Fragum erugatum, and its photosymbiotic microbes provide a remarkable example of a mutualistic partnership in the hypersaline reaches of Shark Bay, Western Australia. Lucinid bivalves and their endosymbiotic chemolithotrophic bacteria provide examples in which hosts span oxic/anoxic interfaces on behalf of their symbionts at sites of seafloor venting. Multiple lines of evidence underscore the antiquity of mutualisms and suggest that they may have played a significant role in life's first experiments above the prokaryotic grade of complexity. The study of metazoan-microbe mutualisms and their signatures in extreme environments in the geologic record will provide a significant augmentation to microbial models in paleobiology and astrobiology. There are strong potential links between mutualisms and the early history of life on Earth, the persistence of life in extreme environments at times of global crisis and mass extinction, and the possibilities for life elsewhere in the universe.

  6. Mollusc-microbe mutualisms extend the potential for life in hypersaline systems.

    PubMed

    Hickman, Carole S

    2003-01-01

    Metazoans in extreme environments have evolved mutualisms with microbes that extend the physical and chemical capabilities of both partners. Some of the best examples are bivalve molluscs in evaporite and hypersaline settings. Mollusc tissue is developmentally and evolutionarily amenable to housing vast numbers of symbiotic microbes. Documented benefits to the host are nutritional. Multiple postulated benefits to the microbes are related to optimizing metabolic performance at interfaces, where heterogeneity and steep gradients that cannot be negotiated by microbes can be spanned by larger metazoan hosts. A small cockle, Fragum erugatum, and its photosymbiotic microbes provide a remarkable example of a mutualistic partnership in the hypersaline reaches of Shark Bay, Western Australia. Lucinid bivalves and their endosymbiotic chemolithotrophic bacteria provide examples in which hosts span oxic/anoxic interfaces on behalf of their symbionts at sites of seafloor venting. Multiple lines of evidence underscore the antiquity of mutualisms and suggest that they may have played a significant role in life's first experiments above the prokaryotic grade of complexity. The study of metazoan-microbe mutualisms and their signatures in extreme environments in the geologic record will provide a significant augmentation to microbial models in paleobiology and astrobiology. There are strong potential links between mutualisms and the early history of life on Earth, the persistence of life in extreme environments at times of global crisis and mass extinction, and the possibilities for life elsewhere in the universe.

  7. On the viscosity of natural hyper-saline solutions and its importance: The Dead Sea brines

    NASA Astrophysics Data System (ADS)

    Weisbrod, Noam; Yechieli, Yoseph; Shandalov, Semion; Lensky, Nadav

    2016-01-01

    The relationship between the density, temperature and viscosity of hypersaline solutions, both natural and synthetic, is explored. An empirical equation of the density-viscosity relationship as a function of temperature was developed for the Dead Sea brine and its dilutions. The viscosity levels of the Dead Sea brine (density of 1.24 ṡ 103 kg/m3; viscosity of 3.6 mPa s at 20 °C) and of the more extremely saline natural brine (density of 1.37 ṡ 103 kg/m3) were found to be ∼3 and ∼10 times greater than that of fresh water, respectively. The combined effect of the above changes in viscosity and density on the hydraulic conductivity is reduction by a factor of 3-7. The chemical composition significantly affects the viscosity of brines with similar densities, whereby solutions with a higher Mg/Na ratio have higher viscosity. This explains the extremely high viscosity of the Dead Sea and related Mg-rich brines in comparison with the much lower values of NaCl and KCl brines with similar density. Possible impacts of the results include reduced settling velocity of grains in hypersaline viscous brines and changing hydraulic dynamics at the freshwater-saltwater and the vicinity of sinkholes.

  8. Determination of Rare Earth Elements in Hypersaline Solutions Using Low-Volume, Liquid-Liquid Extraction.

    PubMed

    Noack, Clinton W; Dzombak, David A; Karamalidis, Athanasios K

    2015-08-18

    Complex, hypersaline brines-including those coproduced with oil and gas, rejected from desalination technologies, or used as working fluids for geothermal electricity generation-could contain critical materials such as the rare earth elements (REE) in valuable concentrations. Accurate quantitation of these analytes in complex, aqueous matrices is necessary for evaluation and implementation of systems aimed at recovering those critical materials. However, most analytical methods for measuring trace metals have not been validated for highly saline and/or chemically complex brines. Here we modified and optimized previously published liquid-liquid extraction (LLE) techniques using bis(2-ethylhexyl) phosphate as the extractant in a heptane diluent, and studied its efficacy for REE recovery as a function of three primary variables: background salinity (as NaCl), concentration of a competing species (here Fe), and concentration of dissolved organic carbon (DOC). Results showed that the modified LLE was robust to a range of salinity, Fe, and DOC concentrations studied as well as constant, elevated Ba concentrations. With proper characterization of the natural samples of interest, this method could be deployed for accurate analysis of REE in small volumes of hyper-saline and chemically complex brines.

  9. PHYLOGENETIC ANALYSIS AND AUTECOLOGY OF SPORE-FORMING BACTERIA FROM HYPERSALINE ENVIRONMENTS.

    PubMed

    Gladka, G V; Romanovskaya, V A; Tashyreva, H O; Tashyrev, O B

    2015-01-01

    Multi-resistant to extreme factors spore-forming bacteria of Bacillus genus are isolated from hypersaline environments of the Crimea (Ukraine) and the Dead Sea (Israel). Phylogenetic analysis showed distinction of dominating extremophilic culturable species in studied regions. In Crimean environments they are B. mojavensis and B. simplex, in the Dead Sea ecosystem--B. subtilis subsp. spizizenii, B. subtilis subsp. subtilis, B. licheniformis and B. simplex. Isolates are simultaneously halotolerant and resistant to UV radiation. Strains isolated from the Dead Sea and the Crimea environments were resistant to UV: LD90 and LD99.99 made 100-170 J/m2 and 750-1500 J/m2 respectively. Spores showed higher UV-resistance (LD99.99-2500 J/m2) than the vegetative cells. However the number of spores made 0.02-0.007% of the whole cell population, and should not significantly affect the UV LD99.99 value. Isolates of both environments were halotolerant in the range of 0.1-10% NaCl and thermotolerant in the range of 20-50 °C, and didn't grow at 15 °C. Survival strategy of spore-forming bacteria from hypersaline environments under high UV radiation level can be performed by spore formation which minimize cell damage as well as efficient DNA-repair systems that remove damages. PMID:26829837

  10. Extremophile microbiomes in acidic and hypersaline river sediments of Western Australia.

    PubMed

    Lu, Shipeng; Peiffer, Stefan; Lazar, Cassandre Sara; Oldham, Carolyn; Neu, Thomas R; Ciobota, Valerian; Näb, Olga; Lillicrap, Adam; Rösch, Petra; Popp, Jürgen; Küsel, Kirsten

    2016-02-01

    We investigated the microbial community compositions in two sediment samples from the acidic (pH ∼3) and hypersaline (>4.5% NaCl) surface waters, which are widespread in Western Australia. In West Dalyup River, large amounts of NaCl, Fe(II) and sulfate are brought by the groundwater into the surface run-off. The presence of K-jarosite and schwertmannite minerals in the river sediments suggested the occurrence of microbial Fe(II) oxidation because chemical oxidation is greatly reduced at low pH. 16S rRNA gene diversity analyses revealed that sequences affiliated with an uncultured archaeal lineage named Aplasma, which has the genomic potential for Fe(II) oxidation, were dominant in both sediment samples. The acidophilic heterotrophs Acidiphilium and Acidocella were identified as the dominant bacterial groups. Acidiphilium strain AusYE3-1 obtained from the river sediment tolerated up to 6% NaCl at pH 3 under oxic conditions and cells of strain AusYE3-1 reduced the effects of high salt content by forming filamentous structure clumping as aggregates. Neither growth nor Fe(III) reduction by strain AusYE3-1 was observed in anoxic salt-containing medium. The detection of Aplasma group as potential Fe(II) oxidizers and the inhibited Fe(III)-reducing capacity of Acidiphilium contributes to our understanding of the microbial ecology of acidic hypersaline environments. PMID:26524974

  11. Determination of Rare Earth Elements in Hypersaline Solutions Using Low-Volume, Liquid-Liquid Extraction.

    PubMed

    Noack, Clinton W; Dzombak, David A; Karamalidis, Athanasios K

    2015-08-18

    Complex, hypersaline brines-including those coproduced with oil and gas, rejected from desalination technologies, or used as working fluids for geothermal electricity generation-could contain critical materials such as the rare earth elements (REE) in valuable concentrations. Accurate quantitation of these analytes in complex, aqueous matrices is necessary for evaluation and implementation of systems aimed at recovering those critical materials. However, most analytical methods for measuring trace metals have not been validated for highly saline and/or chemically complex brines. Here we modified and optimized previously published liquid-liquid extraction (LLE) techniques using bis(2-ethylhexyl) phosphate as the extractant in a heptane diluent, and studied its efficacy for REE recovery as a function of three primary variables: background salinity (as NaCl), concentration of a competing species (here Fe), and concentration of dissolved organic carbon (DOC). Results showed that the modified LLE was robust to a range of salinity, Fe, and DOC concentrations studied as well as constant, elevated Ba concentrations. With proper characterization of the natural samples of interest, this method could be deployed for accurate analysis of REE in small volumes of hyper-saline and chemically complex brines. PMID:25920439

  12. Two Fixed Ratio Dilutions for Soil Salinity Monitoring in Hypersaline Wetlands

    PubMed Central

    Herrero, Juan; Weindorf, David C.; Castañeda, Carmen

    2015-01-01

    Highly soluble salts are undesirable in agriculture because they reduce yields or the quality of most cash crops and can leak to surface or sub-surface waters. In some cases salinity can be associated with unique history, rarity, or special habitats protected by environmental laws. Yet in considering the measurement of soil salinity for long-term monitoring purposes, adequate methods are required. Both saturated paste extracts, intended for agriculture, and direct surface and/or porewater salinity measurement, used in inundated wetlands, are unsuited for hypersaline wetlands that often are only occasionally inundated. For these cases, we propose the use of 1:5 soil/water (weight/weight) extracts as the standard for expressing the electrical conductivity (EC) of such soils and for further salt determinations. We also propose checking for ion-pairing with a 1:10 or more diluted extract in hypersaline soils. As an illustration, we apply the two-dilutions approach to a set of 359 soil samples from saline wetlands ranging in ECe from 2.3 dS m-1 to 183.0 dS m-1. This easy procedure will be useful in survey campaigns and in the monitoring of soil salt content. PMID:26001130

  13. Nutrient budgets and trophic state in a hypersaline coastal lagoon: Lagoa de Araruama, Brazil

    NASA Astrophysics Data System (ADS)

    Souza, Marcelo F. L.; Kjerfve, Björn; Knoppers, Bastiaan; Landim de Souza, Weber F.; Damasceno, Raimundo N.

    2003-08-01

    Lagoa de Araruama in the state of Rio de Janeiro, Brazil, is a hypersaline lagoon with salinity varying spatially from 45 to 56. We collected water samples during monthly cruises throughout the lagoon, and along the streams feeding the system, from April 1991 to March 1992. Nutrients and other water quality parameters exhibited great spatial and temporal variations. Mass balance calculations indicate large amounts of anthropogenic nutrient inputs. The data indicate that the lagoon currently is oligotrophic but is in a state of transition to become a mesotrophic system. Molar dissolved inorganic nitrogen:dissolved inorganic phosphorus (DIN/DIP) varied between 2.2:1 and 659:1 with a volume-weighted average of 22:1. The high DIN/DIP ratio contrasts with that found in nearby lagoons, suggesting that phytoplankton primary production is limited by phosphorus in Lagoa de Araruama. The major loss of DIP is apparently driven by biological assimilation and diagenic reactions in the sediments. Calculations indicate that the lagoon is slightly net autotrophic at +0.9 mol C m -2 yr -1. This suggests that the biomass of the primary producers is restricted by phosphorus availability. Phosphorus retention in the sediment and the hypersaline state of the lagoon prevent changes in autotrophic communities and the formation of eutrophic conditions.

  14. Unveiling microbial activities along the halocline of Thetis, a deep-sea hypersaline anoxic basin.

    PubMed

    Pachiadaki, Maria G; Yakimov, Michail M; LaCono, Violetta; Leadbetter, Edward; Edgcomb, Virginia

    2014-12-01

    Deep-sea hypersaline anoxic basins (DHABs) in the Eastern Mediterranean Sea are considered some of the most hostile environments on Earth. Little is known about the biochemical adaptations of microorganisms living in these habitats. This first metatranscriptome analysis of DHAB samples provides significant insights into shifts in metabolic activities of microorganisms as physicochemical conditions change from deep Mediterranean sea water to brine. The analysis of Thetis DHAB interface indicates that sulfate reduction occurs in both the upper (7.0-16.3% salinity) and lower (21.4-27.6%) halocline, but that expression of dissimilatory sulfate reductase is reduced in the more hypersaline lower halocline. High dark-carbon assimilation rates in the upper interface coincided with high abundance of transcripts for ribulose 1,5-bisphosphate carboxylase affiliated to sulfur-oxidizing bacteria. In the lower interface, increased expression of genes associated with methane metabolism and osmoregulation is noted. In addition, in this layer, nitrogenase transcripts affiliated to uncultivated putative methanotrophic archaea were detected, implying nitrogen fixation in this anoxic habitat, and providing evidence of linked carbon, nitrogen and sulfur cycles. PMID:24950109

  15. Unveiling microbial activities along the halocline of Thetis, a deep-sea hypersaline anoxic basin

    PubMed Central

    Pachiadaki, Maria G; Yakimov, Michail M; LaCono, Violetta; Leadbetter, Edward; Edgcomb, Virginia

    2014-01-01

    Deep-sea hypersaline anoxic basins (DHABs) in the Eastern Mediterranean Sea are considered some of the most hostile environments on Earth. Little is known about the biochemical adaptations of microorganisms living in these habitats. This first metatranscriptome analysis of DHAB samples provides significant insights into shifts in metabolic activities of microorganisms as physicochemical conditions change from deep Mediterranean sea water to brine. The analysis of Thetis DHAB interface indicates that sulfate reduction occurs in both the upper (7.0–16.3% salinity) and lower (21.4–27.6%) halocline, but that expression of dissimilatory sulfate reductase is reduced in the more hypersaline lower halocline. High dark-carbon assimilation rates in the upper interface coincided with high abundance of transcripts for ribulose 1,5-bisphosphate carboxylase affiliated to sulfur-oxidizing bacteria. In the lower interface, increased expression of genes associated with methane metabolism and osmoregulation is noted. In addition, in this layer, nitrogenase transcripts affiliated to uncultivated putative methanotrophic archaea were detected, implying nitrogen fixation in this anoxic habitat, and providing evidence of linked carbon, nitrogen and sulfur cycles. PMID:24950109

  16. Estimation Of River And Lake Heights Using CryoSat-2 Altimetry

    NASA Astrophysics Data System (ADS)

    Villadsen, Heidi; Anderson, Ole B.; Stenseng, Lars

    2013-12-01

    Using a simple threshold retracker on SAR and LRM data from CryoSat-2 it is seen that the SIRAL radar altimeter shows great potential for height estimation over land and inland waters. Differences between heights from the SRTM DEM and the retracked heights were less than 1 m for Lake Va ̈ttern in Sweden, which is well within the error range of 16 m for SRTM. However, some difficulties where encountered, such as snagging due to bright targets off-nadir, as well as an occasional inability of the altimeter to adjust the window delay to the underlying terrain. It was also found, that classification of waveforms over land and inland waters is challenging. Therefore, using a well resolved river and lake mask and focusing on small test regions is recommended until radar altimetry over land and inland waters is fully understood.

  17. Vegetation and carbon sequestration and their relation to water resources in an inland river basin of Northwest China.

    PubMed

    Kang, E; Lu, L; Xu, Z

    2007-11-01

    In the Heihe River Basin in the arid inland area of northwest China, the distribution of water resources in vegetation landscape zones controls the ecosystems. The carbon sequestration capacity of vegetation is analyzed in relation to water resources and vegetation growing conditions. During the last 20 years, the vegetation ecosystems have degenerated in the Heihe River Basin. Simulation using the C-FIX model indicates that, at present, the total amount of NPP of vegetation accounts for about 18.16 TgC, and the average value is 106 gC/m(2)/yr over the whole basin. NPP has generally the highest value in the upperstream mountain area, middlestream artificial oases area, downstream river bank area, alluvial fan and the terminal lake depression where vegetation grows relatively well. The lowest value is found in the vast downstream desert and Gobi area. Protection of vegetation ecosystems and enhancement of carbon sequestration require such inland river basins as the Heihe River Basin to be brought under management in a comprehensive way, taking water as a key, to carry out a rational and efficient allocation and utilization of water resources. PMID:17126989

  18. Using a Freshwater Lake Model Coupled with WRF for Dynamical Downscaling Applications

    EPA Science Inventory

    The ability to represent extremes in temperature and precipitation in regional climates (including those affected by inland lakes) has become an area of focus as regional climate models (RCMs) simulate smaller temporal and spatial scales. When using the Weather Research and Fore...

  19. Diversity of sulfur-cycle prokaryotes in freshwater lake sediments investigated using aprA as the functional marker gene.

    PubMed

    Watanabe, Tomohiro; Kojima, Hisaya; Takano, Yoshinori; Fukui, Manabu

    2013-09-01

    The diversity of sulfate-reducing prokaryotes (SRPs) and sulfur-oxidizing prokaryotes (SOPs) in freshwater lake ecosystems was investigated by cloning and sequencing of the aprA gene, which encodes for a key enzyme in dissimilatory sulfate reduction and sulfur oxidation. To understand their diversity better, the spatial distribution of aprA genes was investigated in sediments collected from six geographically distant lakes in Antarctica and Japan, including a hypersaline lake for comparison. The microbial community compositions of freshwater sediments and a hypersaline sediment showed notable differences. The clones affiliated with Desulfobacteraceae and Desulfobulbaceae were frequently detected in all freshwater lake sediments. The SOP community was mainly composed of four major phylogenetic groups. One of them formed a monophyletic cluster with a sulfur-oxidizing betaproteobacterium, Sulfuricella denitrificans, but the others were not assigned to specific genera. In addition, the AprA sequences, which were not clearly affiliated to either SRP or SOP lineages, dominated the libraries from four freshwater lake sediments. The results showed the wide distribution of some sulfur-cycle prokaryotes across geographical distances and supported the idea that metabolic flexibility is an important feature for SRP survival in low-sulfate environments.

  20. Meeting Report: Knowledge and Gaps in Developing Microbial Criteria for Inland Recreational Waters

    PubMed Central

    Dorevitch, Samuel; Ashbolt, Nicholas J.; Ferguson, Christobel M.; Fujioka, Roger; McGee, Charles D.; Soller, Jeffrey A.; Whitman, Richard L.

    2010-01-01

    The U.S. Environmental Protection Agency (EPA) has committed to issuing in 2012 new or revised criteria designed to protect the health of those who use surface waters for recreation. For this purpose, the U.S. EPA has been conducting epidemiologic studies to establish relationships between microbial measures of water quality and adverse health outcomes among swimmers. New methods for testing water quality that would provide same-day results will likely be elements of the new criteria. Although the epidemiologic studies upon which the criteria will be based were conducted at Great Lakes and marine beaches, the new water quality criteria may be extended to inland waters (IWs). Similarities and important differences between coastal waters (CWs) and IWs that should be considered when developing criteria for IWs were the focus of an expert workshop. Here, we summarize the state of knowledge and research needed to base IWs microbial criteria on sound science. Two key differences between CWs and IWs are the sources of indicator bacteria, which may modify the relationship between indicator microbes and health risk, and the relationship between indicators and pathogens, which also may vary within IWs. Monitoring using rapid molecular methods will require the standardization and simplification of analytical methods, as well as greater clarity about their interpretation. Research needs for the short term and longer term are described. PMID:20100678