Science.gov

Sample records for freshwater bayou prospect

  1. Structural-stratigraphic setting of South Freshwater Bayou Prospect, Vermilion Parish, Louisiana

    SciTech Connect

    Cavanagh, T.; Pilger, R.H. Jr.; Bebout, D.G.; Bachman, A.L.

    1981-01-01

    The primary reservoir targets in South Freshwater Bayou Prospect are sands whose deposition appears to have been structurally controlled. The growth of a deep domal feature localized deepwater sand deposition on its flanks, thereby producing a significant thickness of subsequently geopressured sandstone. The area is, therefore, not only prospective in its own right, but provides an exploration model for other geopressured-geothermal prospects.

  2. Geopressured geothermal resource potential of Miocene Bayou Hebert Prospect, Vermilion and Iberia parishes, Louisiana

    SciTech Connect

    McCulloh, R.P.; Pino, M.A.; Bebout, D.G.; Bachman, A.L.

    1981-01-01

    The Bayou Hebert prospect is a fault-bounded block of lower Miocene shale and sandstone which covers a 75-square-mile area in southeastern Vermilion and southwestern Iberia parishes, southwestern Louisiana. The average depth to the top of the geopressured zone is 12,500 feet. Detailed correlation of shale resistivity patterns on well logs from this area has delineated faults, local unconformities, and changes in thickness and facies of lithologic units. Most faults revealed by this method are associated with the boundary fault zones, but the few delineated in the interior of the prospect could reduce the volume of potential reservoir units. Cross sections show that the lower Miocene section thickens across growth faults by addition of new units as well as by expansion. Of the parameters of reservoir volume, salinity, temperature, and permeability, reservoir volume shows the most significant variation and indicates that the eastern fourth of the prospect has the most geopressured geothermal potential.

  3. Arctic freshwater export: Status, mechanisms, and prospects

    NASA Astrophysics Data System (ADS)

    Haine, Thomas W. N.; Curry, Beth; Gerdes, Rüdiger; Hansen, Edmond; Karcher, Michael; Lee, Craig; Rudels, Bert; Spreen, Gunnar; de Steur, Laura; Stewart, Kial D.; Woodgate, Rebecca

    2015-02-01

    Large freshwater anomalies clearly exist in the Arctic Ocean. For example, liquid freshwater has accumulated in the Beaufort Gyre in the decade of the 2000s compared to 1980-2000, with an extra ≈ 5000 km3 - about 25% - being stored. The sources of freshwater to the Arctic from precipitation and runoff have increased between these periods (most of the evidence comes from models). Despite flux increases from 2001 to 2011, it is uncertain if the marine freshwater source through Bering Strait for the 2000s has changed, as observations in the 1980s and 1990s are incomplete. The marine freshwater fluxes draining the Arctic through Fram and Davis straits are also insignificantly different. In this way, the balance of sources and sinks of freshwater to the Arctic, Canadian Arctic Archipelago (CAA), and Baffin Bay shifted to about 1200 ± 730 km3 yr- 1 freshening the region, on average, during the 2000s. The observed accumulation of liquid freshwater is consistent with this increased supply and the loss of freshwater from sea ice. Coupled climate models project continued freshening of the Arctic during the 21st century, with a total gain of about 50,000 km3 for the Arctic, CAA, and Baffin Bay (an increase of about 50%) by 2100. Understanding of the mechanisms controlling freshwater emphasizes the importance of Arctic surface winds, in addition to the sources of freshwater. The wind can modify the storage, release, and pathways of freshwater on timescales of O(1-10) months. Discharges of excess freshwater through Fram or Davis straits appear possible, triggered by changes in the wind, but are hard to predict. Continued measurement of the fluxes and storage of freshwater is needed to observe changes such as these.

  4. Modelling Freshwater Resources at the Global Scale: Challenges and Prospects

    NASA Astrophysics Data System (ADS)

    Döll, Petra; Douville, Hervé; Güntner, Andreas; Müller Schmied, Hannes; Wada, Yoshihide

    2016-03-01

    Quantification of spatially and temporally resolved water flows and water storage variations for all land areas of the globe is required to assess water resources, water scarcity and flood hazards, and to understand the Earth system. This quantification is done with the help of global hydrological models (GHMs). What are the challenges and prospects in the development and application of GHMs? Seven important challenges are presented. (1) Data scarcity makes quantification of human water use difficult even though significant progress has been achieved in the last decade. (2) Uncertainty of meteorological input data strongly affects model outputs. (3) The reaction of vegetation to changing climate and CO2 concentrations is uncertain and not taken into account in most GHMs that serve to estimate climate change impacts. (4) Reasons for discrepant responses of GHMs to changing climate have yet to be identified. (5) More accurate estimates of monthly time series of water availability and use are needed to provide good indicators of water scarcity. (6) Integration of gradient-based groundwater modelling into GHMs is necessary for a better simulation of groundwater-surface water interactions and capillary rise. (7) Detection and attribution of human interference with freshwater systems by using GHMs are constrained by data of insufficient quality but also GHM uncertainty itself. Regarding prospects for progress, we propose to decrease the uncertainty of GHM output by making better use of in situ and remotely sensed observations of output variables such as river discharge or total water storage variations by multi-criteria validation, calibration or data assimilation. Finally, we present an initiative that works towards the vision of hyperresolution global hydrological modelling where GHM outputs would be provided at a 1-km resolution with reasonable accuracy.

  5. Modelling Freshwater Resources at the Global Scale: Challenges and Prospects

    NASA Technical Reports Server (NTRS)

    Doll, Petra; Douville, Herve; Guntner, Andreas; Schmied, Hannes Muller; Wada, Yoshihide

    2015-01-01

    Quantification of spatially and temporally resolved water flows and water storage variations for all land areas of the globe is required to assess water resources, water scarcity and flood hazards, and to understand the Earth system. This quantification is done with the help of global hydrological models (GHMs). What are the challenges and prospects in the development and application of GHMs? Seven important challenges are presented. (1) Data scarcity makes quantification of human water use difficult even though significant progress has been achieved in the last decade. (2) Uncertainty of meteorological input data strongly affects model outputs. (3) The reaction of vegetation to changing climate and CO2 concentrations is uncertain and not taken into account in most GHMs that serve to estimate climate change impacts. (4) Reasons for discrepant responses of GHMs to changing climate have yet to be identified. (5) More accurate estimates of monthly time series of water availability and use are needed to provide good indicators of water scarcity. (6) Integration of gradient-based groundwater modelling into GHMs is necessary for a better simulation of groundwater-surface water interactions and capillary rise. (7) Detection and attribution of human interference with freshwater systems by using GHMs are constrained by data of insufficient quality but also GHM uncertainty itself. Regarding prospects for progress, we propose to decrease the uncertainty of GHM output by making better use of in situ and remotely sensed observations of output variables such as river discharge or total water storage variations by multi-criteria validation, calibration or data assimilation. Finally, we present an initiative that works towards the vision of hyper resolution global hydrological modelling where GHM outputs would be provided at a 1-km resolution with reasonable accuracy.

  6. Prospects for monitoring freshwater ecosystems towards the 2010 targets

    PubMed Central

    Revenga, C; Campbell, I; Abell, R; de Villiers, P; Bryer, M

    2005-01-01

    Human activities have severely affected the condition of freshwater ecosystems worldwide. Physical alteration, habitat loss, water withdrawal, pollution, overexploitation and the introduction of non-native species all contribute to the decline in freshwater species. Today, freshwater species are, in general, at higher risk of extinction than those in forests, grasslands and coastal ecosystems. For North America alone, the projected extinction rate for freshwater fauna is five times greater than that for terrestrial fauna—a rate comparable to the species loss in tropical rainforest. Because many of these extinctions go unseen, the level of assessment and knowledge of the status and trends of freshwater species are still very poor, with species going extinct before they are even taxonomically classified. Increasing human population growth and achieving the sustainable development targets set forth in 2002 will place even higher demands on the already stressed freshwater ecosystems, unless an integrated approach to managing water for people and ecosystems is implemented by a broad constituency. To inform and implement policies that support an integrated approach to water management, as well as to measure progress in halting the rapid decline in freshwater species, basin-level indicators describing the condition and threats to freshwater ecosystems and species are required. This paper discusses the extent and quality of data available on the number and size of populations of freshwater species, as well as the change in the extent and condition of natural freshwater habitats. The paper presents indicators that can be applied at multiple scales, highlighting the usefulness of using remote sensing and geographical information systems technologies to fill some of the existing information gaps. Finally, the paper includes an analysis of major data gaps and information needs with respect to freshwater species to measure progress towards the 2010 biodiversity targets. PMID

  7. PROSPECTS ON BEHAVIORAL STUDIES OF MARINE AND FRESHWATER TOXINS.

    EPA Science Inventory

    This manuscript is based in large part on an invited presentation. The manuscript provides a brief overview of the growing issue of the human-health and environmental impact of a variety of toxins of marine and freshwater origin, the current (generally crude) state of behavioral...

  8. Screening of three proposed DOE geopressured-geothermal aquifer natural gas project areas for potential conflicting commercial production: Freshwater Bayou, Lake Theriot, and Kaplan, Louisiana

    SciTech Connect

    Knutson, C.F.; Rogers, L.A.

    1982-02-01

    Three proposed DOE geopressured geothermal prospects defined by the Louisiana State University resource assessment group were screened for possible conflict with existing gas production. The analysis used the public records available at the Louisiana Department of Conservation offices in Baton Rouge and structural and statigraphic interpretations made by the L.S.U. resource assessment group. (MHR)

  9. Big Bayou Creek and Little Bayou Creek Watershed Monitoring Program

    SciTech Connect

    Kszos, L.A.; Peterson, M.J.; Ryon; Smith, J.G.

    1999-03-01

    Biological monitoring of Little Bayou and Big Bayou creeks, which border the Paducah Site, has been conducted since 1987. Biological monitoring was conducted by University of Kentucky from 1987 to 1991 and by staff of the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) from 1991 through March 1999. In March 1998, renewed Kentucky Pollutant Discharge Elimination System (KPDES) permits were issued to the US Department of Energy (DOE) and US Enrichment Corporation. The renewed DOE permit requires that a watershed monitoring program be developed for the Paducah Site within 90 days of the effective date of the renewed permit. This plan outlines the sampling and analysis that will be conducted for the watershed monitoring program. The objectives of the watershed monitoring are to (1) determine whether discharges from the Paducah Site and the Solid Waste Management Units (SWMUs) associated with the Paducah Site are adversely affecting instream fauna, (2) assess the ecological health of Little Bayou and Big Bayou creeks, (3) assess the degree to which abatement actions ecologically benefit Big Bayou Creek and Little Bayou Creek, (4) provide guidance for remediation, (5) provide an evaluation of changes in potential human health concerns, and (6) provide data which could be used to assess the impact of inadvertent spills or fish kill. According to the cleanup will result in these watersheds [Big Bayou and Little Bayou creeks] achieving compliance with the applicable water quality criteria.

  10. 88. (Credit CBF) Twelve Mile Bayou Pumping Station and force ...

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

    88. (Credit CBF) Twelve Mile Bayou Pumping Station and force main for pumping water over levee and into the canal (Blind Bayou), March 1913. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

  11. 86. (Credit CBF) Canal between Twelve Mile Bayou and Cross ...

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

    86. (Credit CBF) Canal between Twelve Mile Bayou and Cross Bayou in the bed of Blind Bayou (constructed 1901-1903). Photo taken in November of 1911. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

  12. 33 CFR 117.425 - Black Bayou.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Black Bayou. 117.425 Section 117.425 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.425 Black Bayou. The draws of the...

  13. 33 CFR 117.425 - Black Bayou.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Black Bayou. 117.425 Section 117.425 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.425 Black Bayou. The draws of the...

  14. 33 CFR 117.425 - Black Bayou.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Black Bayou. 117.425 Section 117.425 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.425 Black Bayou. The draws of the...

  15. 33 CFR 117.425 - Black Bayou.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Black Bayou. 117.425 Section 117.425 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.425 Black Bayou. The draws of the...

  16. 33 CFR 117.425 - Black Bayou.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Black Bayou. 117.425 Section 117.425 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.425 Black Bayou. The draws of the...

  17. 33 CFR 117.437 - Colyell Bayou.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Colyell Bayou. 117.437 Section 117.437 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.437 Colyell Bayou. The removable...

  18. 33 CFR 117.497 - Stumpy Bayou.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Stumpy Bayou. 117.497 Section 117.497 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.497 Stumpy Bayou. The removable span of...

  19. 33 CFR 117.437 - Colyell Bayou.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Colyell Bayou. 117.437 Section 117.437 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.437 Colyell Bayou. The removable...

  20. 33 CFR 117.497 - Stumpy Bayou.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Stumpy Bayou. 117.497 Section 117.497 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.497 Stumpy Bayou. The removable span of...

  1. 33 CFR 117.497 - Stumpy Bayou.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Stumpy Bayou. 117.497 Section 117.497 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.497 Stumpy Bayou. The removable span of...

  2. 33 CFR 117.437 - Colyell Bayou.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Colyell Bayou. 117.437 Section 117.437 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.437 Colyell Bayou. The removable...

  3. 33 CFR 117.967 - Greens Bayou.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Greens Bayou. 117.967 Section 117.967 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.967 Greens Bayou. The draw of the Port...

  4. 33 CFR 117.967 - Greens Bayou.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Greens Bayou. 117.967 Section 117.967 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.967 Greens Bayou. The draw of the Port...

  5. 33 CFR 117.957 - Cedar Bayou.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Cedar Bayou. 117.957 Section 117.957 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.957 Cedar Bayou. The draw of the Union...

  6. 33 CFR 117.987 - Taylor Bayou.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Taylor Bayou. 117.987 Section 117.987 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.987 Taylor Bayou. The draws of the Union...

  7. 33 CFR 117.965 - Cow Bayou.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Cow Bayou. 117.965 Section 117.965 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.965 Cow Bayou. The draws of the Orange...

  8. 33 CFR 117.987 - Taylor Bayou.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Taylor Bayou. 117.987 Section 117.987 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.987 Taylor Bayou. The draws of the Union...

  9. 33 CFR 117.959 - Chocolate Bayou.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Chocolate Bayou. 117.959 Section 117.959 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.959 Chocolate Bayou. The draw of the...

  10. 33 CFR 117.957 - Cedar Bayou.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Cedar Bayou. 117.957 Section 117.957 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.957 Cedar Bayou. The draw of the Union...

  11. 33 CFR 117.959 - Chocolate Bayou.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Chocolate Bayou. 117.959 Section 117.959 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.959 Chocolate Bayou. The draw of the...

  12. 33 CFR 117.957 - Cedar Bayou.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Cedar Bayou. 117.957 Section 117.957 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.957 Cedar Bayou. The draw of the Union...

  13. 33 CFR 117.965 - Cow Bayou.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Cow Bayou. 117.965 Section 117.965 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.965 Cow Bayou. The draws of the Orange...

  14. 33 CFR 117.987 - Taylor Bayou.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Taylor Bayou. 117.987 Section 117.987 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.987 Taylor Bayou. The draws of the Union...

  15. 33 CFR 117.965 - Cow Bayou.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Cow Bayou. 117.965 Section 117.965 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.965 Cow Bayou. The draws of the Orange...

  16. 33 CFR 117.955 - Buffalo Bayou.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Buffalo Bayou. 117.955 Section 117.955 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.955 Buffalo Bayou. (a) The draw of...

  17. 33 CFR 117.965 - Cow Bayou.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Cow Bayou. 117.965 Section 117.965 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.965 Cow Bayou. The draws of the Orange...

  18. 33 CFR 117.959 - Chocolate Bayou.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Chocolate Bayou. 117.959 Section 117.959 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.959 Chocolate Bayou. The draw of the...

  19. 33 CFR 117.957 - Cedar Bayou.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Cedar Bayou. 117.957 Section 117.957 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.957 Cedar Bayou. The draw of the Union...

  20. 33 CFR 117.955 - Buffalo Bayou.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Buffalo Bayou. 117.955 Section 117.955 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.955 Buffalo Bayou. (a) The draw of...

  1. 33 CFR 117.967 - Greens Bayou.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Greens Bayou. 117.967 Section 117.967 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.967 Greens Bayou. The draw of the Port...

  2. 33 CFR 117.967 - Greens Bayou.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Greens Bayou. 117.967 Section 117.967 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.967 Greens Bayou. The draw of the Port...

  3. 33 CFR 117.987 - Taylor Bayou.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Taylor Bayou. 117.987 Section 117.987 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.987 Taylor Bayou. The draws of the Union...

  4. 33 CFR 117.959 - Chocolate Bayou.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Chocolate Bayou. 117.959 Section 117.959 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.959 Chocolate Bayou. The draw of the...

  5. 33 CFR 117.955 - Buffalo Bayou.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Buffalo Bayou. 117.955 Section 117.955 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.955 Buffalo Bayou. (a) The draw of...

  6. 33 CFR 117.955 - Buffalo Bayou.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Buffalo Bayou. 117.955 Section 117.955 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.955 Buffalo Bayou. (a) The draw of...

  7. 33 CFR 117.957 - Cedar Bayou.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Cedar Bayou. 117.957 Section 117.957 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.957 Cedar Bayou. The draw of the Union...

  8. 33 CFR 117.959 - Chocolate Bayou.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Chocolate Bayou. 117.959 Section 117.959 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.959 Chocolate Bayou. The draw of the...

  9. 33 CFR 117.987 - Taylor Bayou.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Taylor Bayou. 117.987 Section 117.987 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.987 Taylor Bayou. The draws of the Union...

  10. 33 CFR 117.955 - Buffalo Bayou.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Buffalo Bayou. 117.955 Section 117.955 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.955 Buffalo Bayou. (a) The draw of...

  11. 33 CFR 117.967 - Greens Bayou.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Greens Bayou. 117.967 Section 117.967 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.967 Greens Bayou. The draw of the Port...

  12. 33 CFR 117.965 - Cow Bayou.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Cow Bayou. 117.965 Section 117.965 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.965 Cow Bayou. The draws of the Orange...

  13. 33 CFR 117.469 - Liberty Bayou.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Liberty Bayou. 117.469 Section 117.469 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.469 Liberty Bayou. The draw of...

  14. 33 CFR 117.469 - Liberty Bayou.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Liberty Bayou. 117.469 Section 117.469 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.469 Liberty Bayou. The draw of...

  15. 33 CFR 334.740 - Weekley Bayou, an arm of Boggy Bayou, Fla., at Eglin Air Force Base; restricted area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Weekley Bayou, an arm of Boggy Bayou, Fla., at Eglin Air Force Base; restricted area. 334.740 Section 334.740 Navigation and Navigable... REGULATIONS § 334.740 Weekley Bayou, an arm of Boggy Bayou, Fla., at Eglin Air Force Base; restricted area....

  16. 33 CFR 334.740 - Weekley Bayou, an arm of Boggy Bayou, Fla., at Eglin Air Force Base; restricted area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Weekley Bayou, an arm of Boggy Bayou, Fla., at Eglin Air Force Base; restricted area. 334.740 Section 334.740 Navigation and Navigable... REGULATIONS § 334.740 Weekley Bayou, an arm of Boggy Bayou, Fla., at Eglin Air Force Base; restricted area....

  17. 77 FR 42637 - Drawbridge Operation Regulation; Bayou Boeuf, Amelia, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-20

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulation; Bayou Boeuf, Amelia, LA AGENCY: Coast... (BNSF) Railway Company swing span bridge across ] Bayou Boeuf, mile 10.2, at Amelia, St. Mary Parish... across Bayou Boeuf, mile 10.2, at Amelia, St. Mary Parish, Louisiana. The bridge provides no...

  18. 77 FR 69564 - Drawbridge Operation Regulation; Bayou Boeuf, Amelia, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-20

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulation; Bayou Boeuf, Amelia, LA AGENCY: Coast... (BNSF) Railway Company swing span bridge across Bayou Boeuf, mile 10.2, at Amelia, St. Mary Parish... across Bayou Boeuf, mile 10.2, at Amelia, St. Mary Parish, Louisiana. The bridge provides no...

  19. 2010 FIRST Robotics Bayou Regional Tournament

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Members of the robotics team from St. Patrick Catholic High School in Biloxi, Miss., focus on guiding their robot on the 2010 Bayou Regional playing field during the annual FIRST (For Inspiration and Recognition of Science and Technology) Robotics competition March 5-6. The event attracted 36 teams from eight states, including 25 teams from Louisiana and Mississippi high schools. The tournament was one of dozens of FIRST tournaments scheduled around the country in advance of the national robotics championship in Atlanta in April. The Bayou Regional competition was held at the Alario Center in Westwego, La.

  20. Health assessment for Bayou Sorrel, Bayou Sorrel, Louisiana, Region 6. CERCLIS No. LAD980745541. Final report

    SciTech Connect

    Not Available

    1989-04-06

    The Bayou Sorrel National Priorities List Site is located in Iberville Parish, Louisiana, 6 miles northwest of the community of Bayou Sorrel. The population near Bayou Sorrel is a seasonal one. Fishing, hunting, and vegetable gardens provide a large portion of the diet for many of the inhabitants in the area. The waste types disposed of at Bayou Sorrel included process wastes from pesticide and herbicide manufacture, sulfide-containing wastes, and spent wash solutions from boiler cleaning. The Record of Decision signed November 1986 mandated several remedial actions which included installation of: a runoff control system; caps meeting Resource Conservation and Recovery Act specifications; a sand/geofabric drainage layer and collection system; a gas ventilation system; slurry walls around the former landfill area and Pond 4; a fence around all capped areas; and a ground-water monitoring system.

  1. 2010 FIRST Robotics Bayou Regional Tournament

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Student-built robots maneuver the course during the 2010 Bayou Regional FIRST (For Inspiration and Recognition of Science and Technology) Robotics competition in Westwego on March 5-6. The annual competition drew 36 high school teams from eight states. NASA's John C. Stennis Space Center supports FIRST Robotics by providing financing, mentors and training, as well as competition judges and referees, audiovisual staff and other volunteer personnel.

  2. 75 FR 52937 - Turtle Bayou Gas Storage Company, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ... Energy Regulatory Commission Turtle Bayou Gas Storage Company, LLC; Notice of Application August 20, 2010. Take notice that on August 6, 2010, Turtle Bayou Gas Storage Company, LLC (Turtle Bayou), One Office... caverns and related facilities to be located in Chambers and Liberty Counties, Texas. Turtle Bayou...

  3. 33 CFR 117.471 - Little Black Bayou.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Little Black Bayou. 117.471 Section 117.471 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.471 Little Black Bayou. The draw...

  4. 33 CFR 117.471 - Little Black Bayou.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Little Black Bayou. 117.471 Section 117.471 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.471 Little Black Bayou. The draw...

  5. 33 CFR 117.471 - Little Black Bayou.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Little Black Bayou. 117.471 Section 117.471 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.471 Little Black Bayou. The draw...

  6. 33 CFR 117.471 - Little Black Bayou.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Little Black Bayou. 117.471 Section 117.471 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.471 Little Black Bayou. The draw...

  7. 33 CFR 117.471 - Little Black Bayou.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Little Black Bayou. 117.471 Section 117.471 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.471 Little Black Bayou. The draw...

  8. 78 FR 10523 - Drawbridge Operation Regulation; Bayou Boeuf, Amelia, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-14

    ... (BNSF) Railway Company swing span bridge across Bayou Boeuf, mile 10.2, at Amelia, St. Mary Parish... operating schedule of the swing span railroad bridge across Bayou Boeuf, mile 10.2, at Amelia, St. Mary..., the bridge currently opens on signal for the passage of vessels. This deviation allows the swing...

  9. 33 CFR 117.439 - Des Allemands Bayou.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Des Allemands Bayou. 117.439... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.439 Des Allemands Bayou. (a) The draw of the S631 bridge, mile 13.9 at Des Allemands, shall open on signal if at least four hours notice...

  10. 33 CFR 117.439 - Des Allemands Bayou.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Des Allemands Bayou. 117.439... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.439 Des Allemands Bayou. (a) The draw of the S631 bridge, mile 13.9 at Des Allemands, shall open on signal if at least four hours notice...

  11. 33 CFR 117.439 - Des Allemands Bayou.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Des Allemands Bayou. 117.439... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.439 Des Allemands Bayou. (a) The draw of the S631 bridge, mile 13.9 at Des Allemands, shall open on signal if at least four hours notice...

  12. 77 FR 27115 - Drawbridge Operation Regulation; Bayou Boeuf, Amelia, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-09

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulation; Bayou Boeuf, Amelia, LA AGENCY: Coast... (BNSF) Railway Company swing span bridge across Bayou Boeuf, mile 10.2, at Amelia, St. Mary Parish... Boeuf, mile 10.2, at Amelia, St. Mary Parish, Louisiana. The bridge provides no vertical clearance...

  13. 33 CFR 117.443 - Du Large Bayou.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Du Large Bayou. 117.443 Section 117.443 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.443 Du Large Bayou. The draw of...

  14. 77 FR 57020 - Drawbridge Operation Regulation; Carlin Bayou, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-17

    ... INFORMATION: Table of Acronyms CFR Code of Federal Regulations DHS Department of Homeland Security FR Federal... ``Drawbridge Operation Regulation; Carlin Bayou, LA'' in the Federal Register (77 FR 29927). We received no... Louisiana and Delta Railroad (LDRR) vertical lift bridge across Carlin Bayou in Delcambre, Iberia...

  15. Epidemiology of recreational exposure to freshwater cyanobacteria – an international prospective cohort study

    PubMed Central

    Stewart, Ian; Webb, Penelope M; Schluter, Philip J; Fleming, Lora E; Burns, John W; Gantar, Miroslav; Backer, Lorraine C; Shaw, Glen R

    2006-01-01

    Background Case studies and anecdotal reports have documented a range of acute illnesses associated with exposure to cyanobacteria and their toxins in recreational waters. The epidemiological data to date are limited; we sought to improve on the design of some previously conducted studies in order to facilitate revision and refinement of guidelines for exposure to cyanobacteria in recreational waters. Methods A prospective cohort study was conducted to investigate the incidence of acute symptoms in individuals exposed, through recreational activities, to low (cell surface area <2.4 mm2/mL), medium (2.4–12.0 mm2/mL) and high (>12.0 mm2/mL) levels of cyanobacteria in lakes and rivers in southeast Queensland, the central coast area of New South Wales, and northeast and central Florida. Multivariable logistic regression analyses were employed; models adjusted for region, age, smoking, prior history of asthma, hay fever or skin disease (eczema or dermatitis) and clustering by household. Results Of individuals approached, 3,595 met the eligibility criteria, 3,193 (89%) agreed to participate and 1,331 (37%) completed both the questionnaire and follow-up interview. Respiratory symptoms were 2.1 (95%CI: 1.1–4.0) times more likely to be reported by subjects exposed to high levels of cyanobacteria than by those exposed to low levels. Similarly, when grouping all reported symptoms, individuals exposed to high levels of cyanobacteria were 1.7 (95%CI: 1.0–2.8) times more likely to report symptoms than their low-level cyanobacteria-exposed counterparts. Conclusion A significant increase in reporting of minor self-limiting symptoms, particularly respiratory symptoms, was associated with exposure to higher levels of cyanobacteria of mixed genera. We suggest that exposure to cyanobacteria based on total cell surface area above 12 mm2/mL could result in increased incidence of symptoms. The potential for severe, life-threatening cyanobacteria-related illness is likely to be

  16. The Bayou Choctaw Oil Shipment Test

    SciTech Connect

    Bauer, S.J.; Ballard, S.; Barker, G.T.

    1994-05-01

    In early October of 1993, an oil shipment of about 1 million barrels was made from the Bayou Choctaw Strategic Petroleum Reserve storage facility to St. James Terminal. During the shipment, oil temperatures and soil temperatures along the pipeline were recorded. The field data were used to make estimations of soil thermal properties, thermal conductivity and specific heat. These data were also used to validate and calibrate a heat transfer code, OILPIP, which has been used to calculate pipeline cooling of oil during a drawdown.

  17. 2. VIEW NORTHEAST AT NORTHERN BANK OF BAYOU LAFOURCHE; M/V ...

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

    2. VIEW NORTHEAST AT NORTHERN BANK OF BAYOU LAFOURCHE; M/V 'FOX' LIES UNDER TREES AT CENTER OF PHOTOGRAPH - Motorized Sailing Vessel "Fox", Beached on East Bank ofBayou Lafourche, Larose, Lafourche Parish, LA

  18. Bioaccumulation of human pharmaceuticals in fish across habitats of a tidally influenced urban bayou.

    PubMed

    Du, Bowen; Haddad, Samuel P; Luek, Andreas; Scott, W Casan; Saari, Gavin N; Burket, S Rebekah; Breed, Christopher S; Kelly, Martin; Broach, Linda; Rasmussen, Joseph B; Chambliss, C Kevin; Brooks, Bryan W

    2016-04-01

    Though pharmaceuticals and other contaminants of emerging concern are increasingly observed in inland water bodies, the occurrence and bioaccumulation of pharmaceuticals in estuaries and coastal ecosystems are poorly understood. In the present study, bioaccumulation of select pharmaceuticals and other contaminants of emerging concern was examined in fish from Buffalo Bayou, a tidally influenced urban ecosystem that receives effluent from a major (∼200 million gallons per day) municipal wastewater treatment plant in Houston, Texas, USA. Using isotope dilution liquid chromatography-tandem mass spectrometry, various target analytes were observed in effluent, surface water, and multiple fish species. The trophic position of each species was determined using stable isotope analysis. Fish tissue levels of diphenhydramine, which represented the only pharmaceutical detected in all fish species, did not significantly differ between freshwater and marine fish predominantly inhabiting benthic habitats; however, saltwater fish with pelagic habitat preferences significantly accumulated diphenhydramine to the highest levels observed in the present study. Consistent with previous observations from an effluent-dependent freshwater river, diphenhydramine did not display trophic magnification, which suggests site-specific, pH-influenced inhalational uptake to a greater extent than dietary exposure in this tidally influenced urban ecosystem. The findings highlight the importance of understanding differential bioaccumulation and risks of ionizable contaminants of emerging concern in habitats of urbanizing coastal systems. PMID:26587912

  19. 77 FR 35897 - Drawbridge Operation Regulation; Lafourche Bayou, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... Waterway (GIWW). DATES: The comment period for the proposed rule published April 16, 2012, at 77 FR 22520..., 2008, issue of the Federal Register (73 FR 3316). 4. Public Meeting We do not now plan to hold a public..., ``Drawbridge Operation Regulation; Lafourche Bayou, LA,'' in the Federal Register (77 FR 22520). The...

  20. 77 FR 29927 - Drawbridge Operation Regulation; Carlin Bayou, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-21

    ..., 2008, issue of the Federal Register (73 FR 3316). ] 4. Public Meeting We do not now plan to hold a... SECURITY Coast Guard 33 CFR Part 117 RIN 1625-AA09 Drawbridge Operation Regulation; Carlin Bayou, LA AGENCY... human environment because it simply promulgates the operating regulations or procedures for...

  1. 77 FR 22520 - Drawbridge Operation Regulation; Lafourche Bayou, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-16

    ... Federal Register (73 FR 3316). Public Meeting We do not now plan to hold a public meeting. But you may... SECURITY Coast Guard 33 CFR Part 117 RIN 1625-AA09 Drawbridge Operation Regulation; Lafourche Bayou, LA... of materials, performance, design, or operation; test methods; sampling procedures; and...

  2. 76 FR 52567 - Drawbridge Operation Regulation; Bonfouca Bayou, Slidell, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-23

    ... Federal Register (74 FR 67974). No comments were received. No public hearing was requested and none was... governing the operation of the State Route (SR) 433 Swing Span Bridge across Bonfouca Bayou, mile 7.0, at...) requested that the operating regulation of the SR 433 swing span bridge be changed in order to allow...

  3. 77 FR 46286 - Drawbridge Operation Regulation; Bayou Boeuf, Amelia, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-03

    ... from regulations in the Federal Register (77 FR 42637). The BNSF Railway Company requested this... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulation; Bayou Boeuf, Amelia, LA AGENCY: Coast... Boeuf, mile 10.2, at Amelia, St. Mary Parish, Louisiana. The modification of the date is necessary...

  4. Challenges of watershed implementation plans: Joe's bayou watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Joe’s Bayou watershed is located in the Ouachita River Basin, Louisiana and covers a drainage area of about 173 square kilometers. This watershed is listed on the §303(d) List for Louisiana as impaired for dissolved oxygen (DO) and nutrients. The TMDL report recommends a reduction of 89% of total no...

  5. 75 FR 63714 - Drawbridge Operation Regulation; Des Allemands Bayou, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-18

    ... Burlington Northern Santa Fe Railway swing bridge across Des Allemands Bayou, mile 14.0, in St. Charles and Lafourche Parishes, Louisiana. The deviation is necessary to perform extensive rehabilitation to the bridge. This deviation allows the bridge to remain closed to navigation completely from January 18,...

  6. Streamflow, specific-conductance, and temperature data for Bayou and Little Bayou Creeks near Paducah, Kentucky, August 15 and 16, 1989

    USGS Publications Warehouse

    Evaldi, R.D.; McClain, D.L.

    1989-01-01

    Discharge, temperature, and specific conductance measurements were made August 15 and 16, 1989, at 74 main channel sites and seven flowing tributaries on Bayou and Little Bayou Creeks, Kentucky in the vicinity of the Paducah Gaseous Diffusion Plant. These measurements were made during base flow conditions to provide data for analysis of the interaction of surface and groundwater. The discharge of Bayou Creek was 0.30 cfs at the most upstream site, and 5.8 cfs at the most downstream site. Total measured tributary inflow of Bayou Creek was 5.7 cfs. Specific conductance values in the Bayou Creek watershed ranged from 208 to 489 microsiemens/cm, and water temperature ranged from 20.0 to 32.6 C. The discharge of Little Bayou Creek was 0.65 cfs at the most upstream site, and 1.8 cfs at the most downstream site. Total measured tributary inflow of Little Bayou Creek was 0.38 cfs. Specific conductance values in the Little Bayou Creek watershed ranged from 211 to 272 microsiemens/cm, and water temperature ranged from 14.5 to 24.9 C. (USGS)

  7. Microseismic monitoring of Chocolate Bayou, Texas: the Pleasant Bayou No. 2 geopressured/geothermal energy test well program

    SciTech Connect

    Mauk, F.J.; Kimball, B.; Davis, R.A.

    1984-01-01

    The Brazoria seismic network, instrumentation, design, and specifications are described. The data analysis procedures are presented. Seismicity is described in relation to the Pleasant Bayou production history. Seismicity originating near the chemical plant east of the geopressured/geothermal well is discussed. (MHR)

  8. Microseismic monitoring of Chocolate Bayou Texas: the Pleasant Bayou No. 2 geopressured/geothermal energy test-well program. 1981 annual progress report

    SciTech Connect

    Mauk, F.J.

    1982-01-01

    To investigate normal ambient seismicity as well as potentially enhanced seismic activity induced by brine production, a seismic monitoring program has been conducted in the vicinity of the Chocolate Bayou geopressured test well (the Pleasant Bayou No. 2) since September 1978. The Pleasant Bayou No. 2 well has been completed and perforated at depths of 14,467-14,707 feet (4464.4-4482.7m). The brines produced from the Pleasant Bayou No. 2 well are reinjected at a depth of 6226-6538 feet (1897.7-1992.8m) in the Pleasant Bayou No. 1 well. The seismic monitoring network and results obtained from January through November 1981 are described.

  9. Freshwater Macroinvertebrates.

    ERIC Educational Resources Information Center

    Nalepa, T. F.

    1978-01-01

    Presents a literature review of freshwater biology particularly freshwater macroinvertebrates and their effect on water pollution, covering publications of 1976-77. A list of 158 references is also presented. (HM)

  10. Testing of the Pleasant Bayou Well through October 1990

    SciTech Connect

    Randolph, P.L.; Hayden, C.G.; Mosca, V.L.; Anhaiser, J.L.

    1992-08-01

    Pleasant Bayou location was inactive from 1983 until the cleanout of the production and disposal wells in 1986. The surface facilities were rehabilitated and after shakedown of the system, additional repair of wellhead valves, and injection of an inhibitor pill, continuous long-term production was started in 1988. Over two years of production subsequent to that are reviewed here, including: production data, brine sampling and analysis, hydrocarbon sampling and analysis, solids sampling and analysis, scale control and corrosion monitoring and control.

  11. Brazoria County Re-Leveling Pleasant Bayou Geopressured Well Site

    SciTech Connect

    1984-07-01

    The purpose is to conduct first order leveling surveys as part of an ongoing environmental monitoring program for geopressured-geothermal test wells. The scope is to Conduct First Order, Class I, leveling to monitor subsidence of previously installed and leveled bench marks, established by the National Geodetic Survey (NGS) and Vernon F. Meyer and Associates, Inc., in the area of the Pleasant Bayou geopressured test well. All leveling surveys to conform to NGS standards and specifications.

  12. 77 FR 69562 - Drawbridge Operation Regulation; Barataria Bayou, Lafitte, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-20

    ...The Coast Guard has issued a temporary deviation from the operating schedule that governs the LA 302 (Kerner) swing span bridge across the Barataria Bayou, mile 35.7, at Lafitte, Louisiana. The deviation is necessary to allow a movie production crew to safely film at the bridge site. This deviation allows the bridge to remain closed to navigation for 12 hours on two separate...

  13. 75 FR 9404 - Turtle Bayou Gas Storage Company, LLC; Amended Notice of Intent To Prepare an Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-02

    ... Energy Regulatory Commission Turtle Bayou Gas Storage Company, LLC; Amended Notice of Intent To Prepare an Environmental Assessment for the Planned Turtle Bayou Natural Gas Storage Project and Request for... environmental assessment (EA) that will discuss the environmental impacts of the Turtle Bayou Natural...

  14. 33 CFR 334.760 - Naval Support Activity Panama City and Alligator Bayou, a tributary of St. Andrew Bay, Fla...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... City and Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. 334.760 Section... Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. (a) The area. The waters within... the south side of the entrance to Alligator Bayou; thence directly across the entrance to a point...

  15. 33 CFR 334.760 - Naval Support Activity Panama City and Alligator Bayou, a tributary of St. Andrew Bay, Fla...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... City and Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. 334.760 Section... Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. (a) The area. The waters within... the south side of the entrance to Alligator Bayou; thence directly across the entrance to a point...

  16. 33 CFR 334.760 - Naval Support Activity Panama City and Alligator Bayou, a tributary of St. Andrew Bay, Fla...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... City and Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. 334.760 Section... Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. (a) The area. The waters within... the south side of the entrance to Alligator Bayou; thence directly across the entrance to a point...

  17. 33 CFR 334.760 - Naval Support Activity Panama City and Alligator Bayou, a tributary of St. Andrew Bay, Fla...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... City and Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. 334.760 Section... Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. (a) The area. The waters within... the south side of the entrance to Alligator Bayou; thence directly across the entrance to a point...

  18. 33 CFR 334.760 - Naval Support Activity Panama City and Alligator Bayou, a tributary of St. Andrew Bay, Fla...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... City and Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. 334.760 Section... Alligator Bayou, a tributary of St. Andrew Bay, Fla.; naval restricted area. (a) The area. The waters within... the south side of the entrance to Alligator Bayou; thence directly across the entrance to a point...

  19. Pleasant Bayou Geopressured-Geothermal Reservoir Analysis - January 1991

    SciTech Connect

    Riney, T.D.

    1991-01-01

    Many sedimentary basins contain formations with pore fluids at pressures higher than hydrostatic value; these formations are called geopressured. The pore pressure is generally well in excess of hydrostatic and the fluids vary in scalinity, temperature, and dissolved methane. As part of its program to define the magnitude and recoverability of the geopressured-geothermal energy resource, the US Department of Energy has drilled and tested deep wells in geopressured formations in the Texas-Louisiana Gulf Coast region. Geological information for the Pleasant Bayou geopressured geothermal resource is most extensive among the reservoirs tested. Earlier testing of the DOE well (Pleasant Bayou Well No.2) was conducted in several phases during 1979-1983. Long-term testing was resumed in May 1988 and is currently in progress. This report summarizes the pertinent field and laboratory test data available through December 31, 1990. A numerical reservoir simulator is employed as a tool for synthesizing and integrating the reservoir information, formation rock and fluid properties data from laboratory tests, well data from the earlier testing (1979-1983), and the ongoing long-term production testing (1988-1990) of Pleasant Bayou Well No.2. A reservoir simulation model has been constructed which provides a detailed match to the well test history to date. This model is constructed within a geologic framework described by the Texas Bureau of Economic Geology and relies heavily on the pressure transient data from the 1980 Reservoir Limits Test in conjunction with the 1988-1990 production testing.

  20. 76 FR 16294 - Drawbridge Operation Regulation; Buffalo Bayou, Mile 4.3, Houston, Harris County, TX

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-23

    ... SECURITY Coast Guard 33 CFR Part 117 RIN 1625-AA09 Drawbridge Operation Regulation; Buffalo Bayou, Mile 4.3... removing the existing drawbridge operation regulation for the drawbridge across Buffalo Bayou, mile 4.3... provide the 30 day notice period before its effective date. This rule removes the draw...

  1. Real-Time GPS Network Monitors Bayou Corne Sinkhole Event

    NASA Astrophysics Data System (ADS)

    Kent, Joshua D.; Dunaway, Larry

    2013-10-01

    In August 2012 a sinkhole developed in the swampy marshland near the rural community of Bayou Corne in Assumption Parish (i.e., county), Louisiana. The area was evacuated, and some residents have still not been able to return. The sinkhole—which now measures about 450 meters wide and is continuing to grow—is being monitored by multiple systems, including four rapid-response GPS continuously operating reference stations (CORS) called CORS911. The real-time data provided by this system are used by scientists and decision makers to help ensure public safety.

  2. Bioavailability Assessment of a Contaminated Field Sediemtn from Patrick Bayou, Texas: TIE and Equilibrium Partitioning

    EPA Science Inventory

    Contaminated sediments are commonly found in urbanized harbors. Remediation is often necessary and diagnosing the cause of sediment toxicity becomes imperative. In the present study, sediments from Patrick Bayou, Texas were subjected to initial toxicity testing. All sediments ...

  3. Interpretation of remote sensing data in the Bayou Lafourche Delta of south Louisiana

    NASA Technical Reports Server (NTRS)

    Whitehurst, C. A.

    1975-01-01

    Initial efforts were directed toward a comprehensive ground truth program for the Bayou Lafourche Delta. The impact of transportation systems on the marsh environment, impounded marsh areas, proposed jetty systems at Belle Pass, Louisiana, and erosion and sediment transport in the southwestern canal, Lafourche Parish, Louisiana are studied. The use of color IR imagery for a vegetation study of spoil banks in the Bayou Lafourche Region is also discussed.

  4. Bayou virus-associated hantavirus pulmonary syndrome in Eastern Texas: identification of the rice rat, Oryzomys palustris, as reservoir host.

    PubMed Central

    Torrez-Martinez, N.; Bharadwaj, M.; Goade, D.; Delury, J.; Moran, P.; Hicks, B.; Nix, B.; Davis, J. L.; Hjelle, B.

    1998-01-01

    We describe the third known case of hantavirus pulmonary syndrome (HPS) due to Bayou virus, from Jefferson County, Texas. By using molecular epidemiologic methods, we show that rice rats (Oryzomys palustris) are frequently infected with Bayou virus and that viral RNA sequences from HPS patients are similar to those from nearby rice rats. Bayou virus is associated with O. palustris; this rodent appears to be its predominant reservoir host. PMID:9452404

  5. Features of Bayou Choctaw SPR caverns and internal structure of the salt dome.

    SciTech Connect

    Munson, Darrell E.

    2007-07-01

    The intent of this study is to examine the internal structure of the Bayou Choctaw salt dome utilizing the information obtained from graphical representations of sonar survey data of the internal cavern surfaces. Many of the Bayou Choctaw caverns have been abandoned. Some existing caverns were purchased by the Strategic Petroleum Reserve (SPR) program and have rather convoluted histories and complex cavern geometries. In fact, these caverns are typically poorly documented and are not particularly constructive to this study. Only two Bayou Choctaw caverns, 101 and 102, which were constructed using well-controlled solutioning methods, are well documented. One of these was constructed by the SPR for their use while the other was constructed and traded for another existing cavern. Consequently, compared to the SPR caverns of the West Hackberry and Big Hill domes, it is more difficult to obtain a general impression of the stratigraphy of the dome. Indeed, caverns of Bayou Choctaw show features significantly different than those encountered in the other two SPR facilities. In the number of abandoned caverns, and some of those existing caverns purchased by the SPR, extremely irregular solutioning has occurred. The two SPR constructed caverns suggest that some sections of the caverns may have undergone very regular solutioning to form uniform cylindrical shapes. Although it is not usually productive to speculate, some suggestions that point to the behavior of the Bayou Choctaw dome are examined. Also the primary differences in the Bayou Choctaw dome and the other SPR domes are noted.

  6. Bubbles, Bubbles, Tremors & Trouble: The Bayou Corne Sinkhole

    NASA Astrophysics Data System (ADS)

    Nunn, J. A.

    2013-12-01

    In May 2012, thermogenic methane bubbles were first observed in Bayou Corne in Assumption Parish, Louisiana. As of July 2013, ninety one bubbling sites have been identified. Gas was also found in the top of the Mississippi River Alluvial Aquifer (MRAA) about 125 ft below the surface. Vent wells drilled into the MRAA have flared more 16 million SCF of gas. Trace amounts of hydrogen sulfide also have been detected. Bayou Corne flows above the Napoleonville salt dome which has been an active area for oil and gas exploration since the 1920s. The dome is also a site of dissolution salt mining which has produced large caverns with diameters of up to 300 ft and heights of 2000 ft. Some caverns are used for storage of natural gas. Microseismic activity was confirmed by an Earthscope seismic station in White Castle, LA in July 2012. An array of microseismic stations set up in the area recorded more than 60 microseismic events in late July and early August, 2012. These microseismic events were located on the western side of the dome. Estimated focal depths are just above the top of salt. In August 2012, a sinkhole developed overnight just to the northwest of a plugged and abandoned brine filled cavern (see figure below). The sinkhole continues to grow in area to more than 20 acres and has consumed a pipeline right of way. The sinkhole is more than 750 ft deep at its center. Microseismic activity was reduced for several months following the formation of the sinkhole. Microseismic events have reoccurred episodically since then with periods of frequent events preceding slumping of material into the sinkhole or a 'burp' where fluid levels in the sinkhole drop and then rebound followed by a decrease in microseismic activity. Some gas and/or oil may appear at the surface of the sinkhole following a 'burp'. Very long period events also have been observed which are believed to be related to subsurface fluid movement. A relief well drilled into the abandoned brine cavern found that

  7. Three dimensional simulation for bayou choctaw strategic petroleum reserve (SPR).

    SciTech Connect

    Ehgartner, Brian L. (Sandia National Laboratories, Albuquerque, NM); Park, Byoung Yoon; Lee, Moo Yul

    2006-12-01

    Three dimensional finite element analyses were performed to evaluate the structural integrity of the caverns located at the Bayou Choctaw (BC) site which is considered a candidate for expansion. Fifteen active and nine abandoned caverns exist at BC, with a total cavern volume of some 164 MMB. A 3D model allowing control of each cavern individually was constructed because the location and depth of caverns and the date of excavation are irregular. The total cavern volume has practical interest, as this void space affects total creep closure in the BC salt mass. Operations including both cavern workover, where wellhead pressures are temporarily reduced to atmospheric, and cavern enlargement due to leaching during oil drawdowns that use water to displace the oil from the caverns, were modeled to account for as many as the five future oil drawdowns in the six SPR caverns. The impacts on cavern stability, underground creep closure, surface subsidence, infrastructure, and well integrity were quantified.

  8. Freshwater Wetlands.

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    Provides descriptions about freshwater wetlands, such as marshes, swamps, and bogs. Contains three learning activities which deal with unusual wetland plants, the animals and plants in a typical marsh, and the effects of a draught on a swamp. Included are reproducible handouts and worksheets for two of the activities. (TW)

  9. Freshwater macroinvertebrates

    SciTech Connect

    Quigley, M.A.

    1982-06-01

    Major aspects of the biology of freshwater macroinvertebrates with emphasis on man-induced environmental changes were reviewed in this report with 183 references. The effects of both chemical and physical environmental alteration are examined. The population dynamics of the macroinvertebrates are controlled by factors such as food and feeding habits, periodicity and drift, productivity and animal-sediment interactions.(KRM)

  10. 77 FR 23118 - Annual Marine Events in the Eighth Coast Guard District, Blessing of the Fleet; Bayou La Batre...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-18

    ... SECURITY Coast Guard 33 CFR Part 100 Annual Marine Events in the Eighth Coast Guard District, Blessing of the Fleet; Bayou La Batre; Bayou La Batre, AL AGENCY: Coast Guard, DHS. ACTION: Notice of enforcement of regulation. SUMMARY: The Coast Guard will enforce Special Local Regulations for the Blessing...

  11. Bayou Choctaw Caverns 15 and 17 web analysis

    SciTech Connect

    Ehgartner, B.

    1993-01-01

    The relatively thin web of salt that separates Bayou Choctaw Caverns 15 and 17 was evaluated using the finite-element method. The stability calculations provided insight as to whether or not any operationrestrictions or recommendations are necessary. Because of the uncertainty in the exact dimensions of the salt web, various web thicknesses were examined under different operating scenarios that included individual cavern workovers and drawdowns. Cavern workovers were defined by a sudden drop in the oil side pressure at the wellhead to atmospheric. Workovers represent periods of low cavern pressure. Cavern drawdowns were simulated by enlargening the cavern diameters, thus decreasing the thickness of the web. The calculations predict that Cavern 15 dominates the behavior of the web because of its larger diameter. Thus, giventhe choice of caverns, Cavern 17 should be used for oil withdrawal in order to minimize the adverse impacts on web resulting from pressure drops or cavern enlargement. From a stability point of view, maintaining normal pressures in Cavern 15 was found to be more important than operating the caverns as a gallery where both caverns are maintained at the same pressure. However, during a workover, it may be prudent to operate the caverns under similar pressures to avoid the possibility of a sudden pressure surge at the wellhead should the web fail.

  12. Time of travel of solutes in Buffalo Bayou and selected tributaries, Houston, Texas, August 1999

    USGS Publications Warehouse

    East, Jeffery W.; Schaer, Jasper D.

    2000-01-01

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency, conducted a time-of-travel study in the Buffalo Bayou watershed during low flow in August 1999. The study was done as part of the U.S. Environmental Protection Agency Environmental Monitoring for Public Access and Community Tracking (EMPACT) program. The EMPACT program was designed for the U.S. Environmental Protection Agency to work with communities to “make timely, accurate, and understandable environmental information available to millions of people in the largest metropolitan areas across the country.” (U.S. Environmental Protection Agency, 2000). Buffalo Bayou, located in Houston, Texas, was chosen as a pilot project because it is a frequently used recreational water source, it has many water-treatment facilities located along its stream segments, and it has a history of water-quality problems (Houston-Galveston Area Council, 2000). One component of the pilot project is to develop a water-quality simulation model that can be used to assess the effects of noncompliance events on Buffalo Bayou. Because accurate estimates of time of travel during low flow are required to develop the model, the time of travel of solutes in Buffalo Bayou and selected tributaries was determined using dye tracing methods. The study was conducted during low flow in a 38.7-mile reach of Buffalo Bayou, a 9.6-mile reach of Whiteoak Bayou, a 5.9-mile reach of Mason Creek, and a 6.6-mile reach of Bear Creek. Efforts to determine the time of travel in a 7.5-mile reach of Horsepen Creek were unsuccessful. This report explains the approach used to conduct the study and presents the results of the study

  13. Davis Pond Freshwater Prediversion Biomonitoring Study: Freshwater Fisheries and Eagles

    USGS Publications Warehouse

    Jenkins, Jill A.; Bourgeois, E. Beth; Jeske, Clint W.

    2008-01-01

    In January 2001, the construction of the Davis Pond freshwater diversion structure was completed by the U.S. Army Corps of Engineers. The diversion of freshwater from the Mississippi River is intended to mitigate saltwater intrusion from the Gulf of Mexico and to lessen the concomitant loss of wetland areas. In addition to the freshwater inflow, Barataria Bay basin would receive nutrients, increased flows of sediments, and water-borne and sediment-bound compounds. The purpose of this biomonitoring study was, therefore, to serve as a baseline for prediversion concentrations of selected contaminants in bald eagle (Haliaeetus leucocephalus) nestlings (hereafter referred to as eaglets), representative freshwater fish, and bivalves. Samples were collected from January through June 2001. Two similarly designed postdiversion studies, as described in the biological monitoring program, are planned. Active bald eagle nests targeted for sampling eaglet blood (n = 6) were generally located southwest and south of the diversion structure. The designated sites for aquatic animal sampling were at Lake Salvador, at Lake Cataouatche, at Bayou Couba, and along the Mississippi River. Aquatic animals representative of eagle prey were collected. Fish were from three different trophic levels and have varying feeding strategies and life histories. These included herbivorous striped mullet (Mugil cephalus), omnivorous blue catfish (Ictalurus furcatus), and carnivorous largemouth bass (Micropterus salmoides). Three individuals per species were collected at each of the four sampling sites. Freshwater Atlantic rangia clams (Rangia cuneata) were collected at the downstream marsh sites, and zebra mussels (Dreissena spp.) were collected on the Mississippi River. The U.S. Geological Survey (USGS) Biomonitoring of Environmental Status and Trends (BEST) protocols served as guides for fish sampling and health assessments. Fish are useful for monitoring aquatic ecosystems because they accumulate

  14. Role of pressure, temperature, salinity, lithology, and structure in hydrocarbon accumulation in Constance Bayou, Deep Lake, and southeast Little Pecan Lake Fields, Cameron Parish, Louisiana

    SciTech Connect

    Harrison, F.W. III

    1980-01-01

    Pressure, temperature, salinity, lithology, and structural studies indicate that hydrocarbons in Deep Lake, Constance Bayou, and Little Pecan Lake Fields, were generated in the shale beds of the hard geopressured zone and migrated upward along major growth faults. The hydrocarbons were originally dissolved in hot fresh pore water and came out of solution in the overlying low temperature and pressure zones, accumulating in the sand beds of the first structural traps encountered. By examining regional cross sections and anomaly maps, fluid escape routes taken by the hot pore water containing dissolved hydrocarbons can be identified. Areas below which a vertical flush of hot fresh pore water from the hard geopressured zone has occurred have 3 identifying characteristics: low fluid pressures, high formation water salinity values, and presence of residual high pressure areas. These areas are considered to be highly prospective places to search for hydrocarbon accumulations.

  15. Allegations of diversion and substitution of crude oil. Bayou Choctaw Storage Site, Strategic Petroleum Reserve

    SciTech Connect

    Not Available

    1984-03-30

    Investigation did not substantiate allegations that crude oil destined for the Strategic Petroleum Reserve storage site at Bayou Choctaw was diverted to private use and some other material substituted in its place. However, recommendations are made for handling intermediate transport and storage systems for crude oil to tighten security aspects. (PSB)

  16. 33 CFR 207.185 - Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation. 207.185 Section 207.185 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION...

  17. 33 CFR 207.185 - Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation. 207.185 Section 207.185 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION...

  18. 33 CFR 207.185 - Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation. 207.185 Section 207.185 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION...

  19. 33 CFR 207.185 - Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation. 207.185 Section 207.185 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION...

  20. 33 CFR 207.185 - Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation. 207.185 Section 207.185 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION...

  1. RAINFALL AND RUNOFF AS A SOURCE OF ORGANIC CARBON ADDITIONS TO BAYOU TEXAR, FLORIDA

    EPA Science Inventory

    Rainfall and Runoff as a Source of Organic Carbon Additions to Bayou Texar, Florida (Abstract). To be presented at the16th Biennial Conference of the Estuarine Research Foundation, ERF 2001: An Estuarine Odyssey, 4-8 November 2001, St. Pete Beach, FL. 1 p. (ERL,GB R852).

    T...

  2. THE EFFECT OF PRECIPITATION ON ORGANIC CARBON COMPONENTS IN BAYOU TEXAR, FLORIDA

    EPA Science Inventory

    This study examined the relationship between precipitation and organic carbon in Bayou Texar, part of Florida's Pensacola Bay system in the northern Gulf of Mexico. Weekly samples were collected from five stations between March to June, 1999. Additionally, samples were taken befo...

  3. 77 FR 57492 - Drawbridge Operation Regulation; Grosse Tete Bayou, Iberville Parish, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-18

    ... FR Federal Register NPRM Notice of Proposed Rulemaking Sec. Section Symbol U.S.C. United States Code... Federal Register (FR). The railroad bridge has had no openings in 61 years. It has effectively been a... the Grosse Tete Bayou, mile 14.7, in Iberia Parish, LA has been modified to a fixed bridge;...

  4. Contaminant exposure of barn swallows nesting on Bayou d'Inde, Calcasieu Estuary, Louisiana, USA.

    USGS Publications Warehouse

    Custer, T.W.; Custer, Christine M.; Goatcher, B.L.; Melancon, M.J.; Matson, C.W.; Bickham, J.W.

    2006-01-01

    Current and historical point source discharges, storm water runoff, and accidental spills have contaminated the water, sediment, and biota within the Calcasieu Estuary in southwestern Louisiana. In 2003, barn swallow (Hirundo rustica) eggs and nestlings were collected beneath two bridges that cross Bayou d'Inde, the most contaminated waterway within the Calcasieu Estuary. Samples were also collected from a bridge over Bayou Teche, a reference site in south central Louisiana. Polychlorinated biphenyl (PCB) concentrations in barn swallow eggs and nestlings were significantly higher at the downstream site on Bayou d'Inde (2.8 micro g/g PCBs in eggs and 1.5 micro g/g PCBs in nestlings) than at the other two sites (< 0.2 micro g/g PCBs in eggs and nestlings at both sites). Ethoxyresorufin-O-dealkylase activity in nestling livers was significantly higher at the downstream site on Bayou d'Inde (50 pmol/min/mg) compared to the other two locations (24 pmol/min/mg, each), probably because of exposure to PCBs. Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran concentrations in eggs and polycyclic aromatic hydrocarbons in nestlings were at background concentrations at all sites. Trace element concentrations in barn swallow eggs and nestling livers were at background levels and did not differ among the three sites. A biomarker of DNA damage did not differ among sites.

  5. Contaminant exposure of barn swallows nesting on Bayou d'Inde, Calcasieu Estuary, Louisiana, USA

    USGS Publications Warehouse

    Custer, T.W.; Custer, Christine M.; Goatcher, B.L.; Melancon, M.J.; Matson, C.W.; Bickham, J.W.

    2006-01-01

    Current and historical point source discharges, storm water runoff, and accidental spills have contaminated the water, sediment, and biota within the Calcasieu Estuary in southwestern Louisiana. In 2003, barn swallow (Hirundo rustica) eggs and nestlings were collected beneath two bridges that cross Bayou d'Inde, the most contaminated waterway within the Calcasieu Estuary. Samples were also collected from a bridge over Bayou Teche, a reference site in south central Louisiana. Polychlorinated biphenyl (PCB) concentrations in barn swallow eggs and nestlings were significantly higher at the downstream site on Bayou d'Inde (2.8 mu g/g PCBs in eggs and 1.5 mu g/g PCBs in nestlings) than at the other two sites (< 0.2 mu g/g PCBs in eggs and nestlings at both sites). Ethoxyresorufin-O-dealkylase activity in nestling livers was significantly higher at the downstream site on Bayou d'Inde (50 pmol/min/mg) compared to the other two locations (24 pmol/min/mg, each), probably because of exposure to PCBs. Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran concentrations in eggs and polycyclic aromatic hydrocarbons in nestlings were at background concentrations at all sites. Trace element concentrations in barn swallow eggs and nestling livers were at background levels and did not differ among the three sites. A biomarker of DNA damage did not differ among sites.

  6. Contaminant exposure of barn swallows nesting on Bayou d'Inde, Calcasieu Estuary, Louisiana, USA.

    PubMed

    Custer, Thomas W; Custer, Christine M; Goatcher, Buddy L; Melancon, Mark J; Matson, Cole W; Bickham, John W

    2006-10-01

    Current and historical point source discharges, storm water runoff, and accidental spills have contaminated the water, sediment, and biota within the Calcasieu Estuary in southwestern Louisiana. In 2003, barn swallow (Hirundo rustica) eggs and nestlings were collected beneath two bridges that cross Bayou d'Inde, the most contaminated waterway within the Calcasieu Estuary. Samples were also collected from a bridge over Bayou Teche, a reference site in south central Louisiana. Polychlorinated biphenyl (PCB) concentrations in barn swallow eggs and nestlings were significantly higher at the downstream site on Bayou d'Inde (2.8 micro g/g PCBs in eggs and 1.5 micro g/g PCBs in nestlings) than at the other two sites (< 0.2 micro g/g PCBs in eggs and nestlings at both sites). Ethoxyresorufin-O-dealkylase activity in nestling livers was significantly higher at the downstream site on Bayou d'Inde (50 pmol/min/mg) compared to the other two locations (24 pmol/min/mg, each), probably because of exposure to PCBs. Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran concentrations in eggs and polycyclic aromatic hydrocarbons in nestlings were at background concentrations at all sites. Trace element concentrations in barn swallow eggs and nestling livers were at background levels and did not differ among the three sites. A biomarker of DNA damage did not differ among sites. PMID:16779575

  7. 3-D seismic results in the discovery of significant reserves bypassed for 55 years in the Chocolate Bayou Field

    SciTech Connect

    Pennington, A.; Plant, C.; Davis, C.

    1994-12-31

    The Chocolate Bayou Field is located 25 miles south of Houston, in Southeast Brazoria County, Texas. Discovered in 1938, the field has produced over 2 trillion cubic feet of natural gas and 65 million barrels of oil from approximately 30 sands and 300 wellbores. The majority of the production is from the sands of the upper and middle Frio (Oligocene) section. Accumulation is found on structural highs on both the downthrown and upthrown side of a major basinward growth fault. A 3-D seismic survey was conducted over the field in 1988 in an effort to locate bypassed reserves. Interpretation of the data revealed and unexpected paleo structure associated with a buried and previously undetected counter-regional fault located almost 3 miles south of the structural crest at the Upper Frio level. Detailed structural and isochron mapping with adequate depth conversions indicated that the structure was prospective for trapping of the Lower Frio Sand which were well developed but wet under the Upper Frio structural crest. Although the feature was located on the absolute edge of the survey, the data were adequate to locate two wells which have now been completed in the Lower Frio (RA{sub 4}) section. The sands ranged in thickness from 65 to 115 feet of net pay with porosities from 27 to 30% with sustained production rates in excess of 10,000 million cubic feet of gas and 140 barrels of oil per day per completion.

  8. Freshwater Flow Charts - 1995

    SciTech Connect

    Kaiper, G V

    2003-11-21

    This report covers the following: (1) Explanation of Charts Showing Freshwater Flow in 1995; (2) Estimated U.S. Freshwater Flow in 1995 (chart); (3) Estimated California Freshwater Flow in 1995 (chart); (4) Estimated New Mexico Freshwater Flow in 1995 (chart); and (5) Web locations and credits.

  9. Microseismic monitoring of Chocolate Bayou, Texas. The Pleasant Bayou No. 2 geopressured/geothermal energy test-well program. 1982 annual progress report

    SciTech Connect

    Mauk, F.J.; Davis, R.A.

    1982-01-01

    To investigate the seismic risks associated with geopressured fluid production from the Pleasant Bayou No. 2 design well a seismic monitoring program was conducted in the vicinity of the Brazoria County design wells since 1979. The monitoring program was designed first to establish the nature of the local ambient seismicity prior to production, and second to provide continued surveillance of the area during the well tests to determine if production altered ambient seismic conditions significantly. The operation, data analyses, results and conclusions of the Brazoria seismic network during the operational period from 1 January through 31 December 1982 are described.

  10. Conversion of the Bayou Choctaw geological site characterization report to a three-dimensional model.

    SciTech Connect

    Stein, Joshua S.; Rautman, Christopher Arthur

    2004-02-01

    The geologic model implicit in the original site characterization report for the Bayou Choctaw Strategic Petroleum Reserve Site near Baton Rouge, Louisiana, has been converted to a numerical, computer-based three-dimensional model. The original site characterization model was successfully converted with minimal modifications and use of new information. The geometries of the salt diapir, selected adjacent sedimentary horizons, and a number of faults have been modeled. Models of a partial set of the several storage caverns that have been solution-mined within the salt mass are also included. Collectively, the converted model appears to be a relatively realistic representation of the geology of the Bayou Choctaw site as known from existing data. A small number of geometric inconsistencies and other problems inherent in 2-D vs. 3-D modeling have been noted. Most of the major inconsistencies involve faults inferred from drill hole data only. Modem computer software allows visualization of the resulting site model and its component submodels with a degree of detail and flexibility that was not possible with conventional, two-dimensional and paper-based geologic maps and cross sections. The enhanced visualizations may be of particular value in conveying geologic concepts involved in the Bayou Choctaw Strategic Petroleum Reserve site to a lay audience. A Microsoft WindowsTM PC-based viewer and user-manipulable model files illustrating selected features of the converted model are included in this report.

  11. 76 FR 45421 - Safety Zone; Houma Navigation Canal, From Waterway Mile Markers 19.0 to 20.0, Southwest of Bayou...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-29

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AAOO Safety Zone; Houma Navigation Canal, From Waterway Mile... the Houma Navigation Canal, from Waterway Mile Markers 19.0 to 20.0, Southwest of Bayou Plat, bank to.../Barriers in the Houma Navigation Canal, from Waterway Mile Markers 19.0 to 20.0, southwest of Bayou...

  12. Nutrient loading and selected water-quality and biological characteristics of Dickinson Bayou near Houston, Texas, 1995-97

    USGS Publications Warehouse

    East, Jeffery W.; Paul, Edna M.; Porter, Stephen D.

    1998-01-01

    Algal samples were collected at seven stations and were analyzed for periphyton identification and enumeration, and chlorophyll a and chlorophyll b concentrations. The large relative abundance of soil algae at stations in the middle of the watershed likely indicates the cumulative effects on water quality of agricultural nonpoint sources. Farther downstream near the State Highway 3 bridge, and downstream of three major tributary inflows, the increase in abundance of soil algae to a larger-than-expected level might reflect water-quality influences from predominantly urban nonpoint sources in the drainage basins of the three major tributary inflows. Nutrient concentrations do not appear to limit algal production in the upper (non-tidal) reach of Dickinson Bayou; but nutrient concentrations could have been limiting benthicalgal production in the lower (tidal) reach of the bayou during the time of the synoptic survey. If nitrogen is the limiting resource for algal productivity in the tidal reach of Dickinson Bayou, eutrophi

  13. Influence of water allocation and freshwater inflow on oyster production: a hydrodynamic-oyster population model for Galveston Bay, Texas, USA.

    PubMed

    Powell, Eric N; Klinck, John M; Hofmann, Eileen E; McManus, Margaret A

    2003-01-01

    A hydrodynamic-oyster population model was developed to assess the effect of changes in freshwater inflow on oyster populations in Galveston Bay, Texas, USA. The population model includes the effects of environmental conditions, predators, and the oyster parasite, Perkinsus marinus, on oyster populations. The hydrodynamic model includes the effects of wind stress, river runoff, tides, and oceanic exchange on the circulation of the bay. Simulations were run for low, mean, and high freshwater inflow conditions under the present (1993) hydrology and predicted hydrologies for 2024 and 2049 that include both changes in total freshwater inflow and diversions of freshwater from one primary drainage basin to another. Freshwater diversion to supply the Houston metropolitan area is predicted to negatively impact oyster production in Galveston Bay. Fecundity and larval survivorship both decline. Mortality from Perkinsus marinus increases, but to a lesser extent. A larger negative impact in 2049 relative to 2024 originates from the larger drop in fecundity under that hydrology. Changes in recruitment and mortality, resulting in lowered oyster abundance, occur because the bay volume available for mixing freshwater input from the San Jacinto and Buffalo Bayou drainage basins that drain metropolitan Houston is small in comparison to the volume of Trinity Bay that presently receives the bulk of the bay's freshwater inflow. A smaller volume for mixing results in salinities that decline more rapidly and to a greater extent under conditions of high freshwater discharge.Thus, the decline in oyster abundance results from a disequilibrium between geography and salinity brought about by freshwater diversion. Although the bay hydrology shifts, available hard substrate does not. The simulations stress the fact that it is not just the well-appreciated reduction in freshwater inflow that can result in decreased oyster production. Changing the location of freshwater inflow can also

  14. An integrated approach to reservoir engineering at Pleasant Bayou Geopressured-Geothermal reservoir

    SciTech Connect

    Shook, G.M.

    1992-12-01

    A numerical model has been developed for the Pleasant Bayou Geothermal-Geopressured reservoir. This reservoir description is the result of integration of a variety of data, including geological and geophysical interpretations, pressure transient test analyses, and well operations. Transient test analyses suggested several enhancements to the geologic description provided by University of Texas Bureau of Economic Geology (BEG), including the presence of an internal fault not previously identified. The transient tests also suggested water influx from an adjacent aquifer during the long-term testing of Pleasant Bayou; comparisons between transient test analyses and the reservoir description from BEG suggests that this fault exhibits pressure-dependent behavior. Below some pressure difference across the fault, it remains a no-flow barrier; above this threshold pressure drop the barrier fails, and fluid moves across the fault. A history match exercise is presented, using the hypothesized {open_quotes}leaky fault.{close_quotes} Successful match of 4 years of production rates and estimates of average reservoir pressure supports the reservoir description developed herein. Sensitivity studies indicate that the degree of communication between the perforated interval and the upper and lower sands in the reservoir (termed {open_quotes}distal volume{close_quotes} by BEG) impact simulation results very little, whereas results are quite sensitive to storage and transport properties of this distal volume. The prediction phase of the study indicates that Pleasant Bayou is capable of producing 20,000 STB/d through 1997, with the final bottomhole pressure approximately 1600 psi above abandonment pressure.

  15. Geomechanical testing of Bayou Choctaw 102B core for SPR analysis

    SciTech Connect

    Ingraham, Mathew Duffy; Broome, Scott Thomas; Bauer, Stephen J.; Barrow, Perry Carl; Flint, Gregory Mark

    2014-02-01

    A laboratory testing program was developed to examine the short-term mechanical and time-dependent (creep) behavior of salt from the Bayou Choctaw Salt Dome. This report documents the test methodologies, and constitutive properties inferred from tests performed. These are used to extend our understanding of the mechanical behavior of the Bayou Choctaw domal salt and provide a data set for numerical analyses. The resulting information will be used to support numerical analyses of the current state of the Bayou Choctaw Dome as it relates to its crude oil storage function as part of the US Strategic Petroleum Reserve. Core obtained from Drill Hole BC-102B was tested under creep and quasi-static constant mean stress axisymmetric compression, and constant mean stress axisymmetric extension conditions. Creep tests were performed at 100 degrees Fahrenheit, and the axisymmetric tests were performed at ambient temperatures (72-78 degrees Fahrenheit). The testing performed indicates that the dilation criterion is pressure and stress state dependent. It was found that as the mean stress increases, the shear stress required to cause dilation increases. The results for this salt are reasonably consistent with those observed for other domal salts. Also it was observed that tests performed under extensile conditions required consistently lower shear stress to cause dilation for the same mean stress, which is consistent with other domal salts. Young's moduli ranged from 3.95 x 106 to 8.51 x 106 psi with an average of 6.44 x 106 psi, with Poisson's ratios ranging from 0.10 to 0.43 with an average of 0.30. Creep testing indicates that the BC salt is intermediate in creep resistance when compared with other bedded and domal salt steady-state behavior.

  16. Proceedings of the global climate change and freshwater ecosystems

    SciTech Connect

    Firth, P.; Fisher, S.G.

    1992-01-01

    This book discusses global climate change which is a certainty. The Earth's climate has never remained static for long and the prospect for human-accelerated climate change in the near future appears likely. Freshwater systems are intimately connected to climate in several ways. They may influence, or even drive, global atmospheric processes affecting climate (e.g., biogenic gas emissions from freshwater wetlands). They may be sensitive early indicators of climate change because they integrate the atmospheric and terrestrial events occurring in their catchments. And, of course, they will be affected by climate change. Freshwater hydrological processes, freshwater resources, and freshwater ecosystems have historically responded to climatic shifts and we fully expect that they will continue to do so. Climate-induced changes may include altered water temperatures, runoff, nutrient flux, discharge, flow regime, lake and aquifer levels, water quality, ice cover, suspended load, primary and secondary production, trophic dynamics, organism ranges, and migration patterns.

  17. Tremors in the Bayou: The Events on the Napoleonville Salt Dome, Louisiana

    NASA Astrophysics Data System (ADS)

    Ellsworth, W. L.; Horton, S.; Benz, H.; Hickman, S.; Leeds, A.; Leith, W. S.; Meremonte, M.; Rubinstein, J. L.; Withers, M. M.; Herrmann, R. B.

    2012-12-01

    Beginning in early June, 2012, an extended series of earth tremors were reported by residents of Bayou Corne in Assumption Parish, Louisiana, and at well control facilities on the nearby Napoleonville salt dome. The salt dome contains numerous caverns resulting from solution mining; some are used to store LPG and natural gas while others produce saltwater brine. Residents also reported natural gas bubbling at nearby locations in Bayou Corne and Grand Bayou. Some of the tremors were large enough to produce "cracks in sheet rock and foundations" (The Advocate, Baton Rouge, July 5, 2012). It was thus quite surprising to find that no earthquakes were detected in this region by either the USGS NEIC or the USArray Array Network Facility despite the presence of Transportable Array station 544A only 10 km from Bayou Corne. Careful inspection of the seismograms at 544A did reveal multiple events characterized by virtually no body wave energy and strong surface waves at the times of reported tremors. In response to a request for assistance from the State of Louisiana six temporary seismic stations with Trillium broad band sensors were deployed in the immediate epicentral region by the USGS and University of Memphis starting on July 12. Seismograms recorded by the temporary stations revealed a variable rate of tremor activity, with several hundred events registered on active days. Even at very close distance (S-P < 0.5 s) the body waves are weak and surface waves prominent, indicating a very shallow source depth. Precise location of the events is complicated by the presence of the high-seismic velocity and steep-sided Napoleonville salt dome that reaches to within 220 m of the surface and is overlain and surrounded by very low velocity sediments. Following several repositionings of the seismic network we have determined that the source region lies on the western edge of the salt dome top at very shallow depth and in the vicinity of an abandoned brine supply cavern. Tremor

  18. 77 FR 39422 - Eighth Coast Guard District Annual Safety Zones; Niceville July 4th Fireworks Show; Boggy Bayou...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-03

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Eighth Coast Guard District Annual Safety Zones; Niceville July 4th Fireworks Show; Boggy Bayou; Niceville, FL AGENCY: Coast Guard, DHS. ACTION: Notice of enforcement of regulation. SUMMARY: The Coast Guard will enforce a Safety Zone for the Niceville July...

  19. Threat of a sinkhole: A reevaluation of Cavern 4, Bayou Choctaw salt dome, Louisiana

    SciTech Connect

    Neal, J.T.; Todd, J.L.; Linn, J.K.; Magorian, T.R.

    1993-09-01

    Cavern Lake at Bayou Choctaw salt dome resulted from the failure of Cavern 7 in 1954. Uncontrolled solutioning of this cavern through the thin caprock had set the stage for overburden to collapse into the cavern below. A similar situation developed with nearby Cavern 4, but with less dissolutioning of the caprock. Because pressure loss was already a problem and because another 800 ft diameter lake would have endangered surface operations, solutioning of Cavern 4 was stopped and the cavern abandoned in 1957 in order to protect the already-small site. In 1978 the Strategic Petroleum Reserve (SPR) acquired a number of caverns at Bayou Choctaw, including Cavern 4, and the possible repeat of the Cavern 7 failure and formation of another lake thus became an issue. The cavern dimensions were re-sonared in 1980 for comparison with 1963 and 1977 surveys. Annual surface leveling between 1982--1992 showed less subsidence occurring than the site average, and a cavern monitoring system, installed in 1984, has revealed no anomalous motion. Repeat sonar surveys in 1992 showed very little, if any, change occurred since 1980 although a small amount of uncertainty exists as a result of changing sonar techniques. We conclude that significant additional solutioning or erosion of the caprock has not occurred and that there is no increased threat to SPR operations.

  20. Expansion analyses of strategic petroleum reserve in Bayou Choctaw : revised locations.

    SciTech Connect

    Ehgartner, Brian L.; Park, Byoung Yoon

    2010-11-01

    This report summarizes a series of three-dimensional simulations for the Bayou Choctaw Strategic Petroleum Reserve. The U.S. Department of Energy plans to leach two new caverns and convert one of the existing caverns within the Bayou Choctaw salt dome to expand its petroleum reserve storage capacity. An existing finite element mesh from previous analyses is modified by changing the locations of two caverns. The structural integrity of the three expansion caverns and the interaction between all the caverns in the dome are investigated. The impacts of the expansion on underground creep closure, surface subsidence, infrastructure, and well integrity are quantified. Two scenarios were used for the duration and timing of workover conditions where wellhead pressures are temporarily reduced to atmospheric pressure. The three expansion caverns are predicted to be structurally stable against tensile failure for both scenarios. Dilatant failure is not expected within the vicinity of the expansion caverns. Damage to surface structures is not predicted and there is not a marked increase in surface strains due to the presence of the three expansion caverns. The wells into the caverns should not undergo yield. The results show that from a structural viewpoint, the locations of the two newly proposed expansion caverns are acceptable, and all three expansion caverns can be safely constructed and operated.

  1. Turtle Bayou - 1936 to 1983: case history of a major gas field in south Louisiana

    SciTech Connect

    Cronquist, C.

    1983-01-01

    Turtle Bayou field, located in the middle Miocene trend in S. Louisiana, is nearing the end of a productive life which spans over 30 yr. Discovered by Shell Oil Co. in 1949 after unsuccessful attempts by 2 other majors, the field is a typical, low relief, moderately faulted Gulf Coast structure, probably associated with deep salt movement. The productive interval includes 22 separate gas-bearing sands in a regressive sequence of sands and shales from approx. 6500 to 12,000 ft. Now estimated to have contained ca 1.2 trillion scf of gas in place, cumulative production through 1982 was 702 billion scf. Cumulative condensate-gas ratio has been 20 bbl/million. Recovery mechanisms in individual reservoirs include strong bottom water drive, partial edgewater drive, and pressure depletion. Recovery efficiencies in major reservoirs range from 40 to 75% of original gas in place.

  2. Construction of hexahedral elements mesh capturing realistic geometries of Bayou Choctaw SPR site

    SciTech Connect

    Park, Byoung Yoon; Roberts, Barry L.

    2015-09-01

    The three-dimensional finite element mesh capturing realistic geometries of Bayou Choctaw site has been constructed using the sonar and seismic survey data obtained from the field. The mesh is consisting of hexahedral elements because the salt constitutive model is coded using hexahedral elements. Various ideas and techniques to construct finite element mesh capturing artificially and naturally formed geometries are provided. The techniques to reduce the number of elements as much as possible to save on computer run time with maintaining the computational accuracy is also introduced. The steps and methodologies could be applied to construct the meshes of Big Hill, Bryan Mound, and West Hackberry strategic petroleum reserve sites. The methodology could be applied to the complicated shape masses for not only various civil and geological structures but also biological applications such as artificial limbs.

  3. Effects of polychlorinated dibenzo-p-dioxins and dibenzofurans on nesting wood ducks (Aix sponsa) at Bayou Meto, Arkansas.

    PubMed

    White, D H; Hoffman, D J

    1995-05-01

    Wood ducks (Aix sponsa) nesting along Bayou Meto downstream from a hazardous waste site in central Arkansas were contaminated with polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Residues in eggs, based on 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ), ranged up to 611 parts per trillion (ppt), and egg arithmetic means were 90-fold higher at the site nearest the point source compared with a reference site. We monitored productivity of wood ducks in artificial nest boxes at three sites on the bayou and at a reference site on a separate drainage during 1988-1990. Productivity was suppressed (p < 0.05) at the bayou sites compared with the reference site, and egg TCDD-EQs were inversely correlated (p < 0.001) with productivity in corresponding nests. The threshold range of toxicity, where reduced productivity was evident in wood ducks (based on TCDD-EQs), was > 20 to 50 ppt. Oxidative stress and teratogenic effects occurred in ducklings at the more contaminated nesting sites nearest the point source. These findings suggest that wood ducks may be more sensitive to PCDD and PCDF contamination than some other aquatic birds and could serve as an indicator species for monitoring biological impacts from these contaminants. PMID:7556022

  4. Superfund Record of Decision (EPA Region 6): Bayou Sorrel, Louisiana, November 1986. First remedial action. Final report

    SciTech Connect

    Not Available

    1986-11-14

    The Bayou Sorrel site is located in Iberville Parish, Louisiana approximately 20 miles southwest of Baton Rouge, LA. Fifty acres of the 265-acre site have been used for waste disposal. The waste-disposal areas consist of four landfills: a spent-lime cell, a crushed-drum cell, four covered liquid-waste ponds, and a land farm. The remaining acres are covered by dense brush and trees. The entire site has a marshy, bayou-type environment and is prone to flooding and poor drainage. Early in 1977, the Environmental Purification Advancement Corporation (EPAC) began operating the Bayou Sorrel site. A sister firm, Clean Land Air Water, Inc. (CLAW) operated an injection well approximately six miles south of the site. EPAC operations included landfarming, open liquid impoundments, drum burial, and landfilling of chemically fixated wastes. The fixation process is unknown but may have included lime, cement, and native soils. EPAC and CLAW were two separate operations, however, it was suggested that wastes from the injection well were diverted to EPAC when process problems at the well caused a bottleneck. In the summer of 1978, a truck driver died at the site.

  5. Bayou Saigon.

    ERIC Educational Resources Information Center

    Epstein, Nadine

    1994-01-01

    Vietnamese immigrants constitute 28% of the population of the small town of Amelia, Louisiana. Vietnamese are characterized by their neighbors as family oriented, hardworking, and self-disciplined. The principal of the local elementary school describes the Vietnamese students as bright and motivated. The local Vietnamese priest expresses concern…

  6. Freshwater Marsh. Habitat Pac.

    ERIC Educational Resources Information Center

    Fish and Wildlife Service (Dept. of Interior), Washington, DC.

    The materials in this educational packet are designed for use with students in grades 4 through 7. They consist of an overview, three lesson plans and student data sheets, and a poster. The overview describes how the freshwater marsh is an important natural resource for plant, animal, and human populations and how the destruction of marshes causes…

  7. Soil Biogeochemical Properties and Erosion Source Prediction Model Summary for the Buffalo Bayou Watershed, Houston, Texas

    NASA Astrophysics Data System (ADS)

    Ahmed, I.

    2015-12-01

    We draw conclusions on the research output and findings from a 4-year multidisciplinary USDA-CBG collaborative program in sustainable integrated monitoring of soil organic carbon (SOC) loss prediction via erosion. The underlying method uses the state-of-the-art stable isotope science of sediment tracing under uncertain hydrologic influences. The research finds are rooted in the (i) application of Bayesian Markov Chain Monte Carlo statistical models to assess the relationship between rainfall-runoff and soil erosion in space and time, (ii) capture of the episodic nature of rainfall events and its role in the spatial distribution of SOC loss from water erosion, (iii) stable isotope composition guided fingerprinting (source and quantity) of eroded soil, and (iv) the creation of an integrated watershed scale statistical soil loss monitoring model driven by spatial and temporal correlation of flow and stable isotope composition. The research theme was successfully applied on the urbanized Buffalo Bayou Watershed in Houston, Texas. The application brought to light novel future research conceptual outlines which will also be discussed in this deliverable to the AGU meeting. These include but not limited to: regional rainfall cluster research, physics of muddy river-bank soil and suspended sediment interaction, and friction & mobility that together make up the plasticity of soil aggregates that control erosion processes and landscape changes in a riparian corridor. References: Ahmed, I., Karim, A., Boutton, T.W., and Strom, K.B. (2013a). "Monitoring Soil Organic Carbon Loss from Erosion Using Stable Isotopes." Proc., Soil Carbon Sequestration, International Conference, May 26-29, Reykjavik, Iceland. Ahmed, I, Bouttom, T.W., Strom, K. B., Karim, A., and Irvin-Smith, N. (2013b). "Soil carbon distribution and loss monitoring in the urbanized Buffalo Bayou watershed, Houston, Texas." Proc., 4th Annual All Investigators Meeting of the North American Carbon Program, February 4

  8. Acidification of freshwaters

    SciTech Connect

    Cresser, M.S.; Edwards, A.C.

    1987-01-01

    This volume gives an account that draws not only on the main branches of chemistry but also on soil physics, chemistry, hydrology, meteorology, geography, geology, plant physiology, soil microbiology and zoology. The author examine the numerous interacting physical, chemical, and biological, processes that regulate the acidity of freshwaters, a phenomenon that has various causes, including precipitation; acidifying pollutions; and the interaction of plants, soils and water. The relative importance of the different processes is examined.

  9. Digital model of the Bayou Bartholomew alluvial aquifer stream system, Arkansas

    USGS Publications Warehouse

    Reed, J.E.; Broom, Matthew E.

    1979-01-01

    A digital model of the Bayou Bartholomew aquifer-stream system in Arkansas was calibrated for the purpose of predicting hydrologic responses to stresses of water development. The simulated-time span for model calibration was from 1953 to 1970, during which time the system was stressed largely by ground- and surface-water diversions for rice irrigation. The model was calibrated by comparing groundwater-level and streamflow data with model-derived groundwater levels and streamflow. In the calibrated model, the ratio of model-derived to observed streamflows for 17 subbasins averaged 1.1; the ratios among the subbasins ranged from 0.8 to 1.6. The average deviation of the differences between model-derived and observed groundwater levels at 47 nodes was 0.2; the average among the nodes ranged from -2.3 to 10.4. The average standard deviation of the differences between the model-derived and observed groundwater levels was 3.5; the average among the nodes ranged from 0.4 to 10.5. The model will provide projections of changes in the potentiometric surface resulting from (1) changes in the rate or distribution of groundwater pumpage or (2) changes in the stage of streams and reservoirs. The model will provide only approximate projections of the streamflow. (USGS)

  10. Turtle Bayou 1936-1983: case history of a major gas field in south Louisiana

    SciTech Connect

    Cronquist, C.

    1984-11-01

    Turtle Bayou field, located in the middle Miocene trend in south Louisiana, is nearing the end of a productive life spanning more than 30 years. Discovered by Shell Oil Co. in 1949 after unsuccessful attempts by two other companies, the field is a typical, low-relief, moderately faulted U.S. Gulf Coast structure, probably associated with deep salt movement. The productive interval includes 22 separate gas-bearing sands in a regressive sequence of sands and shales from approximately 6,500 to 12,000 ft (1980 to 3660 m). Now estimated to have contained about 1.2 trillion scf (34 X 10/sup 9/ std m/sup 3/) of gas in place, cumulative production through 1982 was 702 billion scf (20 X 10/sup 9/ std m/sup 3/). Cumulative condensate/gas ration (CGR) has been 20 bbl/MMcf (110 X 10/sup -6/ m/sup 3//m/sup 3/. Recovery mechanisms in individual reservoirs include strong bottomwater drive, partial edgewater drive, and pressure depletion. Recovery efficiencies in major reservoirs range form 40 to 83% of original gas in place (OGIP). On decline since 1973, it is anticipated the field will be essentially depleted in the next 5 years.

  11. Turtle Bayou--1936 to 1983--case history of a major gas field in South Louisiana

    SciTech Connect

    Cronquist, C.

    1983-10-01

    Turtle Bayou Field, located in the middle Miocene trend in South Louisiana, is nearing the end of a productive life which spans over 30 years. Discovered by Shell Oil Company in 1949 after unsuccessful attempts by two other majors, the field is a typical, low relief, moderately faulted Gulf Coast structure, probably associated with deep salt movement. The productive interval includes 22 separate gas-bearing sands in a regressive sequence of sands and shales from approximately 6500 to 12,000 feet. Now estimated to have contained about 1.2 trillion standard cubic feet of gas in place, cumulative production through 1982 was 702 billion standard cubic feet. Cumulative condensate-gas ratio has been 20 barrels per million. Recovery mechanisms in individual reservoirs include strong bottom water drive, partial edgewater drive, and pressure depletion. Recovery efficiencies in major reservoirs range from 40 to 75 percent of original gas in place. On decline since 1973, it is anticipated the field will be essentially depleted in the next five years.

  12. Pleasant Bayou geopressured/geothermal testing project, Brazoria County, Texas. Final report

    SciTech Connect

    Ortego, P.K.

    1985-07-01

    Phase II-B production testing of the Pleasant Bayou No. 2 well began September 22, 1982. The test plan was designed to evaluate the capabilities of the geopressured-geothermal reservoir during an extended flow period. Tests were conducted to determine reservoir areal extent; aquifer fluid properties; fluid property change with production; information on reservoir production drive mechanism; long-term scale and corrosion control methods; and disposal well operations. Operatinal aspects of geopressured-geothermal production were also evaluated. The test was discontinued prematurely in May 1983 because of a production tubing failure. Most of the production tubing was recovered from the well and cause of the failure was determined. Plans for recompletion of the well were prepared. However, the well was not recompleted because of funding constraints and/or program rescheduling. In March 1984, the Department of Energy, Nevada Operations Office (DOE/NV) directed that the site be placed in a standby-secured condition. In August 1984, the site was secured. Routine site maintenance and security was provided during the secured period.

  13. Mobilization of trace metals and inorganic compounds during resuspension of anoxic sediments from Trepangier Bayou, Louisiana.

    PubMed

    Shipley, Heather J; Gao, Yan; Kan, Amy T; Tomson, Mason B

    2011-01-01

    The release of trace metals (Mn, Ni, Co, Cu, Zn, Pb, and Cd) and inorganic compounds (As) from initially anoxic Trepangier Bayou sediments, Louisiana and the sources of the released metals were investigated. After 1 to 2 d aeration, significant amounts of trace metals (Mn, Zn, Cd, Ni, and Co) were released to the aqueous phase with increased acidity, primarily due to the oxidation of acid-volatile sulfide and ferrous iron and iron sulfide minerals. The addition of a bacterial inhibitor, NaN,, to the Trepangier sediment during resuspension inhibited metal release, suggesting that microbial catalysis can regulate metal mobilization during sediment resuspension. In a well buffered system, oxidation of iron sulfides alone did not appear to induce trace metal release. Moreover, when Trepangier sediment was resuspended in anoxic conditions at neutral pH, <1% of the trace metal content was released, whereas a significant release of metal was observed under acidic anoxic conditions. Although oxidation of iron sulfide minerals is an essential prerequisite for the release of Zn, Co, Cd, and Ni, carbonates and oxides also play a role. The trace metals and inorganic compounds investigated could be classified into three groups according to their release characteristics: (i) Mn, Zn, Cd, Ni, and Co; (ii) Fe, Pb, and As; and (iii) Cu. The groupings appeared to depend on the sources of compounds and their relative affinity, after oxidation, to iron oxyhydroxides or organic matter. PMID:21520756

  14. Freshwater wetlands and wildlife

    SciTech Connect

    Sharitz, R.R.; Gibbons, J.W.

    1989-01-01

    This volume is a product of the Freshwater Wetlands and Wildlife symposium held in Charleston, South Carolina, on March 24--27, 1986 and contains 94 papers. The stimulus for the symposium came from our interest in augmenting the findings of the long-term research programs on freshwater wetlands and wildlife that have been carried out on the US Department of Energy's Savannah River Site in South Carolina. The symposium provided a forum on an international scale for the exchange of data about freshwater ecosystems: their functions, uses, and their future. The papers in this volume address issues related to natural, man-managed, and degraded ecosystems. The volume is divided into two sections. The first section deals with the functions and values of wetlands, including their use as habitat for plants and animals, their role in trophic dynamics, and their basic processes. The second section treats the subject of their status and management, including techniques for assessing their value, laws for protecting them, and plans for properly managing them. Individual papers will be indexed and entered separately on the energy data base.

  15. Dispersal and persistence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in a contaminated aquatic ecosystem, Bayou Meto, Arkansas

    SciTech Connect

    Heckathorn, W.D.; Johnson, J.E.; Thompson, A.L.

    1995-12-31

    In 1991, sediment and fish samples were collected from Bayou Meto above and below the Vertac Chemical Corporation in Jacksonville, Arkansas. The purpose of this study was to: (1) assess present concentrations of dioxins in sediments and fishes of Bayou Meto; (2) compare the present concentrations and distribution of dioxins in Bayou Meto to concentrations found in previous studies; (3) examine the dispersion of TCOD from its point source; and (4) compare experimental theories on biomagnification with the field findings. The sediment and fish were collected from twelve sites on Bayou Meto, and two sites on Wattensaw Bayou. Concentrations of 2,3,7,8-TCDD were elevated in sediment and fish samples at levels sufficient to pose a threat to fish and wildlife resources. TCDD concentrations remained above background levels downstream, grading in a classic pattern of dispersion from a single point source. For all samples, the higher chlorinated congeners were orders of magnitude higher than the TCDD concentrations. The highest TCDD concentration in sediments and fishes were found immediately downstream from Rocky Branch at river km 250. TCDD concentrations in fish and sediment samples were elevated above background level to the furthest downstream sampling station at river km 36. However, TCDD levels in Bayou Meto sediments have declined over time by dispersion and sedimentation. Juvenile bluegills consistently contained 2.4 times more TCDD than did the smallmouth buffalo, and 6.2 times more TCDD than the largemouth bass. Bluegill samples at the sampling station below Rocky Branch were the only fish where concentrations exceeded those of the sediments. Fishes do not appear to biomagnify TCDD. TCDD body burdens of fishes appear to be determined primarily by lipid concentrations and secondarily by association to the sediments and diet.

  16. A validation test for Adagio through replication of Big Hill and Bayou Choctaw JAS3D models.

    SciTech Connect

    Park, Byoung Yoon

    2013-06-01

    JAS3D, a three dimensional iterative solid mechanics code, has been used for structural analyses for the Strategic Petroleum Reserve system since the 1990s. JAS3D is no longer supported by Sandia National Laboratories, and has been replaced by Adagio. To validate the transition from JAS3D to Adagio, the existing JAS3D input decks and user subroutines for Bayou Choctaw and Big Hill models were converted for use with Adagio. The calculation results from the Adagio runs are compared to the JAS3D. Since the Adagio results are very similar to the JAS3D results, Adagio is judged to be performing satisfactorily.

  17. Effects of pollution on freshwater organisms

    SciTech Connect

    Phipps, G.L.; Harden, M.J.; Leonard, E.N.; Roush, T.H; Spehar, D.L.; Stephan, C.E.; Pickering, Q.H.; Buikema, A.L. Jr.

    1984-06-01

    This review includes subjects in last year's reviews on effects of pollution on freshwater invertebrates and effects of pollution on freshwater fish and amphibians. This review also includes information on the effects of pollution on freshwater plants. 625 references.

  18. Strategic Petroleum Reserve (SPR) additional geologic site characterization studies, Bayou Choctaw salt dome, Louisiana

    SciTech Connect

    Neal, J.T.; Magorian, T.R.; Byrne, K.O.; Denzler, S.

    1993-09-01

    This report revises and updates the geologic site characterization report that was published in 1980. Revised structure maps and sections show interpretative differences in the dome shape and caprock structural contours, especially a major east-west trending shear zone, not mapped in the 1980 report. Excessive gas influx in Caverns 18 and 20 may be associated with this shear zone. Subsidence values at Bayou Choctaw are among the lowest in the SPR system, averaging only about 10 mm/yr but measurement and interpretation issues persist, as observed values often approximate measurement accuracy. Periodic, temporary flooding is a continuing concern because of the low site elevation (less than 10 ft), and this may intensify as future subsidence lowers the surface even further. Cavern 4 was re-sonared in 1992 and the profiles suggest that significant change has not occurred since 1980, thereby reducing the uncertainty of possible overburden collapse -- as occurred at Cavern 7 in 1954. Other potential integrity issues persist, such as the proximity of Cavern 20 to the dome edge, and the narrow web separating Caverns 15 and 17. Injection wells have been used for the disposal of brine but have been only marginally effective thus far; recompletions into more permeable lower Pleistocene gravels may be a practical way of increasing injection capacity and brinefield efficiency. Cavern storage space is limited on this already crowded dome, but 15 MMBBL could be gained by enlarging Cavern 19 and by constructing a new cavern beneath and slightly north of abandoned Cavern 13. Environmental issues center on the low site elevation: the backswamp environment combined with the potential for periodic flooding create conditions that will require continuing surveillance.

  19. Arctic freshwater synthesis: Introduction

    NASA Astrophysics Data System (ADS)

    Prowse, T.; Bring, A.; Mârd, J.; Carmack, E.

    2015-11-01

    In response to a joint request from the World Climate Research Program's Climate and Cryosphere Project, the International Arctic Science Committee, and the Arctic Council's Arctic Monitoring and Assessment Program, an updated scientific assessment has been conducted of the Arctic Freshwater System (AFS), entitled the Arctic Freshwater Synthesis (AFSΣ). The major reason for joint request was an increasing concern that changes to the AFS have produced, and could produce even greater, changes to biogeophysical and socioeconomic systems of special importance to northern residents and also produce extra-Arctic climatic effects that will have global consequences. Hence, the key objective of the AFSΣ was to produce an updated, comprehensive, and integrated review of the structure and function of the entire AFS. The AFSΣ was organized around six key thematic areas: atmosphere, oceans, terrestrial hydrology, terrestrial ecology, resources and modeling, and the review of each coauthored by an international group of scientists and published as separate manuscripts in this special issue of Journal of Geophysical Research-Biogeosciences. This AFSΣ—Introduction reviews the motivations for, and foci of, previous studies of the AFS, discusses criteria used to define the domain of the AFS, and details key characteristics of the definition adopted for the AFSΣ.

  20. Sperm in "parhenogenetic" freshwater gastrotrichs.

    PubMed

    Weiss, M J; Levy, D P

    1979-07-20

    Freshwater members of the phylum Gastrotricha have been considered obligate parthenogens. In Lepidodermelia squammata, the species for which there is most evidence for parthenogenesis, sperm have been discovered. This finding will necessitate reexamination of the nature of sexuality and life cycles and of the concept of "species" in freshwater gastrotrichs. PMID:17747043

  1. Effects of polychlorinated dibenzo-p-dioxins and dibenzofurans on nesting wood ducks (Aix Sponsa) at Bayou Meto, Arkansas

    USGS Publications Warehouse

    White, D.H.; Hoffman, D.J.

    1995-01-01

    Wood ducks (Aix sponsa) nesting along Bayou Meto downstream from a hazardous waste site in central Arkansas were contaminated with polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Residues in eggs, based on 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ), ranged up to 611 parts per trillion (ppt), and egg arithmetic means were 90-fold higher at the site nearest the point source compared with a reference site. We monitored productivity of wood ducks in artificial nest boxes at three sites on the bayou and at a reference site on a separate drainage during 1988-1990. Productivity was suppressed (p 20 to 50 ppt. Oxidative stress and teratogenic effects occurred in ducklings at the more contaminated nesting sites nearest the point source. These findings suggest that wood ducks may be more sensitive to PCDD and PCDF contamination than some other aquatic birds and could serve as an indicator species for monitoring biological impacts from these contaminants.

  2. Freshwater withdrawals in Texas, 1985

    USGS Publications Warehouse

    Lurry, Dee L.; Barber, Nancy L.

    1990-01-01

    Freshwater withdrawal data was compiled for the 254 counties in Texas for 1985. Major categories of withdrawal are presented by county on maps of the State. Withdrawals are also shown by source, aquifer, and major river basin. Total freshwater withdrawals in Texas during 1985 were about 20, 100 million gal/day. Surface-water withdrawals were about 12,900 million gal/day or 64% of the total, and groundwater withdrawals were about 7,190 million gal/day or 36% of the total. More water was withdrawn for irrigation than for any other purpose, accounting for 40% of total freshwater withdrawals and for 75% of groundwater withdrawals. (USGS)

  3. Characterizing Micro- and Macro-Scale Seismicity from Bayou Corne, Louisiana

    NASA Astrophysics Data System (ADS)

    Baig, A. M.; Urbancic, T.; Karimi, S.

    2013-12-01

    The initiation of felt seismicity in Bayou Corne, Louisiana, coupled with other phenomena detected by residents on the nearby housing development, prompted a call to install a broadband seismic network to monitor subsurface deformation. The initial deployment was in place to characterize the deformation contemporaneous with the formation of a sinkhole located in close proximity to a salt dome. Seismic events generated during this period followed a swarm-like behaviour with moment magnitudes culminating around Mw2.5. However, the seismic data recorded during this sequence suffer from poor signal to noise, onsets that are very difficult to pick, and the presence of a significant amount of energy arriving later in the waveforms. Efforts to understand the complexity in these waveforms are ongoing, and involve invoking the complexities inherent in recording in a highly attenuating swamp overlying a complex three-dimensional structure with the strong material property contrast of the salt dome. In order to understand the event character, as well as to locally lower the completeness threshold of the sequence, a downhole array of 15 Hz sensors was deployed in a newly drilled well around the salt dome. Although the deployment lasted a little over a month in duration, over 1000 events were detected down to moment magnitude -Mw3. Waveform quality tended to be excellent, with very distinct P and S wave arrivals observable across the array for most events. The highest magnitude events were seen as well on the surface network and allowed for the opportunity to observe the complexities introduced by the site effects, while overcoming the saturation effects on the higher-frequency downhole geophones. This hybrid downhole and surface array illustrates how a full picture of subsurface deformation is only made possible by combining the high-frequency downhole instrumentation to see the microseismicity complemented with a broadband array to accurately characterize the source

  4. A Possible Source Model for VLP Signals in Bayou Corne, LA

    NASA Astrophysics Data System (ADS)

    Leidig, M.; Stroujkova, A. F.

    2013-12-01

    Very Long Period (VLP) signals have been recorded in the Bayou Corne area since the formation of a sinkhole resulting from failed a salt cavern. Sediment and/or water migration is hypothesized to be responsible for these signals. Some key observations regarding these signals include: 1. VLP signals are best recorded at an individual station (LA12) to the southwest of the sinkhole. 2. First VLP event detected 3 days after the sinkhole formed, months after the first seismic events. 3. VLP events increase dramatically in the days preceding sinkhole activity. 4. Natural gas migration potentially occurred for a period of time, possibly months, prior to first VLP event detection. 5. Area near LA12 has undergone at least 2 m of subsidence. 6. VLP activity has continued, even as the cavern has nearly filled with sediment. We have examined various possible source mechanisms in order to understand the origin of the VLP signals. A damped oscillator model in which a surface layer vibrates in response to external disturbances best describes the observed VLP events. The model likely represents the shallow Upper Aquitard (UA) oscillating on top of the Mississippi River Alluvial Aquifer (MRAA). In order for the clay layer of the UA to undulate, the sediments in the MRAA would need to be in a fluidized state, with a viscosity similar to tar or magma. The MRAA is fully saturated with water, and small injections of water into the MRAA could temporarily and locally fluidize the sands and disturb the UA creating a VLP event. In addition, small earthquakes can disturb the system and trigger the oscillations. Lateral movement of fluidized sediments could also disturb the UA and generate a VLP in addition to explaining subsidence near LA12. Lateral extrusion of material into the sinkhole also fits with the lack of detected VLP events prior to the sinkhole formation and the increase in VLP events prior to sinkhole activity. Repeated mappings of the sinkhole geometry indicate the maximum

  5. Subsurface geology and potential for geopressured-geothermal energy in the Turtle Bayou field-Kent Bayou field area, Terrebonne Parish, Louisiana

    SciTech Connect

    Moore, D.R.

    1982-09-01

    A 216 square mile area approximately 65 miles southwest of New Orleans, Louisiana, has been geologically evaluated to determine its potential for geopressured-geothermal energy production. The structural and stratigraphic analyses were made with emphasis upon the Early and Middle Miocene age sediments which lie close to and within the geopressured section. Three geopressured sands, the Robulus (43) sand, Cibicides opima sand, and Cristellaria (I) sand, are evaluated for their potential of producing geothermal energy. Two of these sands, the Robulus (43) sand and the Cibicides opima sand, meet several of the United States Department of Energy's suggested minimum requirements for a prospective geopressured-geothermal energy reservoir.

  6. [Lactobacilli of freshwater fishes].

    PubMed

    Kvasnikov, E I; Kovalenko, N K; Materinskaia, L G

    1977-01-01

    Normal microflora in the intestinal tract of fishes inhabiting fresh-water reservoirs includes lactic bacteria. The number of the bacteria depends on the animal species, the composition of food, the age, and the season. The highest number of these microorganisms (hundreds of millions per gram of the intestinal content) is found in carps. Enterococci are most often encountered in fishes inhabiting ponds: Streptococcus faecalis Andrewes a. Horder, Str. faecium Orla-Jensen, Str. bovis Orla-Jensen. Lactobacilli are more typical of fishes in water reserviors: Lactobacillus plantarum (Orla-Jensen) Bergey et al., L. casei (Orla-Jensen) Hansen a. Lessel, L. casei var. casei, L. casei var. rhamnosus, L. Casei var. alactosus, L. leichmannii (Henneberg) Bergey et al., L. acidophillus (Moro) Hansen a. Mocquot, L. Fermenti Beijerinck, L. cellobiosus Rogosa et al., L. Buchneri (Henneberg) Bergey et al. The content of lactic bacteria varies in water reservoirs; their highest content is found in ooze (tens of thousands per gram). PMID:909475

  7. Summary statistics and graphical comparisons of specific conductance, temperature, and dissolved oxygen data, Buffalo Bayou, Houston, Texas, April 1986-March 1991

    USGS Publications Warehouse

    Brown, D.W.; Paul, E.M.

    1995-01-01

    Buffalo Bayou is the major stream that drains the Houston, Texas, metropolitan area. The U.S. Geological Survey has provided specific conductance, temperature, and dissolved oxygen data to the City of Houston for three sites along a 7.7-mile reach of Buffalo Bayou since 1986. Summary statistics and graphical comparisons of the data show substantial variability in the properties during 1986-91. Specific conductance ranged from about 100 microsiemens per centimeter at 25 degrees Celsius at each of the three sites to 17,100 microsiemens per centimeter at 25 degrees Celsius at the most downstream site, at the headwaters of the Houston Ship Channel. Water temperatures ranged from 5 to 33 degrees Celsius. Temperatures were very similar at the two upstream sites and slightly warmer at the most downstream site. Dissolved oxygen ranged from zero at the most downstream site to 11.7 milligrams per liter at the most upstream site.

  8. Superfund Record of Decision (EPA Region 6): Petro-Chemical (Turtle Bayou), Liberty County, TX. (Second remedial action), September 1991. Final report

    SciTech Connect

    Not Available

    1991-09-06

    The 500-acre Petro-Chemical (Turtle Bayou) site is in Liberty County, Texas. Current land use in the area is divided among cropland, pasture, range, forest, and small rural communities. Since 1971, numerous undocumented disposal activities occurred onsite involving primarily petrochemical wastes. The ROD for OU2 focuses on three areas of contamination at the site affecting soil and ground water contamination, known as the main waste area, the east disposal area, and the Bayou disposal area. The primary contaminants of concern affecting the soil and ground water are VOCs including benzene and xylenes; other organics including PAHs; and metals including lead. The selected remedial action for the site includes treating 302,800 cubic yards of contaminated soil onsite using in-situ vapor extraction to remove VOCs, controlling vertical air infiltration using an engineered soil and synthetic liner cap; consolidating lead-contaminated soil in the Main Waste Area, followed by capping.

  9. Inhabitants of the Fresh-Water Community.

    ERIC Educational Resources Information Center

    Jorgensen, Joseph; Schroeder, Marlene

    This learner's guide is designed to assist middle school students in studying freshwater organisms. Following a brief introduction to freshwater ecology, simple line drawings facilitate the identification of plants and animals common to Florida's freshwater ecosystems. Emphasis of the short text which accompanies each illustration is upon the…

  10. Cable Bacteria in Freshwater Sediments

    PubMed Central

    Kristiansen, Michael; Frederiksen, Rasmus B.; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and electric fields indicated electron transfer between vertically separated anodic and cathodic half-reactions. Fluorescence in situ hybridization revealed the presence of Desulfobulbaceae filaments. In addition, in situ measurements of oxygen, pH, and electric potential distributions in the waterlogged banks of Giber Å demonstrated the presence of distant electric redox coupling in naturally occurring freshwater sediment. At the same site, filamentous Desulfobulbaceae with cable bacterium morphology were found to be present. Their 16S rRNA gene sequence placed them as a distinct sister group to the known marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary origin of the cable phenotype within Desulfobulbaceae with subsequent diversification into a freshwater and a marine lineage. PMID:26116678

  11. Cable Bacteria in Freshwater Sediments.

    PubMed

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus B; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-09-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and electric fields indicated electron transfer between vertically separated anodic and cathodic half-reactions. Fluorescence in situ hybridization revealed the presence of Desulfobulbaceae filaments. In addition, in situ measurements of oxygen, pH, and electric potential distributions in the waterlogged banks of Giber Å demonstrated the presence of distant electric redox coupling in naturally occurring freshwater sediment. At the same site, filamentous Desulfobulbaceae with cable bacterium morphology were found to be present. Their 16S rRNA gene sequence placed them as a distinct sister group to the known marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary origin of the cable phenotype within Desulfobulbaceae with subsequent diversification into a freshwater and a marine lineage. PMID:26116678

  12. Effects of Stormwater Pipe Size and Rainfall on Sediment and Nutrients Delivered to a Coastal Bayou.

    PubMed

    Grigas, Daniel; Lehrter, John; Cebrian, Just; Chen, Yushun; Ehmen, Brenna; Woodrey, Mark

    2015-09-01

    Pollutants discharged from stormwater pipes can cause water quality and ecosystem problems in coastal bayous. A study was conducted to characterize sediment and nutrients discharged by small and large (< 20 cm and >20 cm in internal diameters, respectively) pipes under different rainfall intensities (< 2.54 cm and > 2.54 cm, respectively). Results showed that large pipes had greater discharge than small pipes. Pollutants concentrations did not vary by pipe size. Large pipes had greater loads of TSS (138.2 vs. 24.0 mg/s), NO3(-) (5.54 vs. 2.74 mg/s), and NH4(+) (0.39 vs. 0.19 mg/s) than small pipes. Neither discharge nor constituents varied by rainfall events. Pipe size may be a useful metric for estimating loads to a system. Nutrient reduction efforts should be directed to reducing the dissolved nutrient pools, while stormwater management efforts should be directed to reducing pipe freshwater discharge volumes that drive constituent loads. PMID:26961474

  13. Sonar atlas of caverns comprising the U.S. Strategic Petroleum Reserve. Volume 1, Bayou Choctaw site, Louisiana.

    SciTech Connect

    Rautman, Christopher Arthur; Lord, Anna Snider

    2007-10-01

    Downhole sonar surveys from the four active U.S. Strategic Petroleum Reserve sites have been modeled and used to generate a four-volume sonar atlas, showing the three-dimensional geometry of each cavern. This volume 1 focuses on the Bayou Choctaw SPR site, located in southern Louisiana. Volumes 2, 3, and 4, respectively, present images for the Big Hill SPR site, Texas, the Bryan Mound SPR site, Texas, and the West Hackberry SPR site, Louisiana. The atlas uses a consistent presentation format throughout. The basic geometric measurements provided by the down-cavern surveys have also been used to generate a number of geometric attributes, the values of which have been mapped onto the geometric form of each cavern using a color-shading scheme. The intent of the various geometrical attributes is to highlight deviations of the cavern shape from the idealized cylindrical form of a carefully leached underground storage cavern in salt. The atlas format does not allow interpretation of such geometric deviations and anomalies. However, significant geometric anomalies, not directly related to the leaching history of the cavern, may provide insight into the internal structure of the relevant salt dome.

  14. Water quality for freshwater fish

    SciTech Connect

    Howells, G. )

    1994-01-01

    This timely and up-to-date volume brings together recent critical reviews on water quality requirements for freshwater fish commissioned by the European Inland Fisheries Advisory Commission, an agency of the United Nations Food and Agriculture Organization. It provides a unique and authoritative source of critically evaluated water quality data concerning the effects of chromium, nickel, aluminum and nitrite on freshwater fish and includes an assessment of the toxicity of mixtures. The reports presented in this volume cover all stages of the life cycle and relevant trophic levels, including aquatic invertebrates and plants and potential bioaccumulation through the food chain. An extensive bibliography is provided for each chapter as well as a glossary of terms and a list of fish species mentioned in the text. This compilation of papers is the definitive reference volume for chemists, biologists, ecologists and toxicologists as well as for water resource managers concerned with management and control of pollution in fresh waters.

  15. Freshwater Biodiversity and Insect Diversification

    PubMed Central

    Dijkstra, Klaas-Douwe B.; Monaghan, Michael T.; Pauls, Steffen U.

    2016-01-01

    Inland waters cover less than one percent of Earth’s surface, but harbor more than six percent of all insect species: nearly 100,000 species from 12 orders spend one or more life stages in freshwater. Little is known about how this remarkable diversity arose, although allopatric speciation and ecological adaptation are thought to be primary mechanisms. Freshwater habitats are exceptionally susceptible to environmental change, and exhibit marked ecological gradients. The amphibiotic lifestyles of aquatic insects result in complex contributions of extinction and allopatric and non-allopatric speciation in species diversification. In contrast to the lack of evolutionary studies, the ecology and habitat preferences of aquatic insects have been intensively studied, in part because of their widespread use as bio-indicators. The combination of phylogenetics with the extensive ecological data provides a promising avenue for future research, making aquatic insects highly suitable models for the study of ecological diversification. PMID:24160433

  16. Sulfur cycling in freshwater sediments

    NASA Technical Reports Server (NTRS)

    Klug, M. J.

    1985-01-01

    Organic sulfur containing compounds represent greater than 80% of the total sulfur in sediments of eutrophic freshwater lakes. Although sedimentary sulfur is predominantly in the form of organic compounds, more sulfur is transformed by sulfate reduction than by any other process. Rates of sulfate reduction in these sediments average 7 mmol/sq m/day. This rate is 19 times greater than the net rate of production of inorganic sulfur from organic compounds on an annual basis.

  17. Estimated freshwater withdrawals in Texas, 1990

    USGS Publications Warehouse

    Lurry, Dee L.

    1994-01-01

    Freshwater withdrawals in Texas during 1990 were estimated as part of the U.S. Geological Survey's National Water Use Information Program. Estimates of freshwater withdrawals were made for five categories of use: irrigation, thermoelectric- power generation, water supply, industrial and mining, and domestic/commercial/livestock. Total freshwater withdrawals for the State were estimated to be 20,100 Mgal/d (million gallons per day). Ground water was estimated to account for 37 percent (7,390 Mgal/d), and surface water was estimated to account for 63 percent (12,700 Mgal/d) of total withdrawals. The largest withdrawals of freshwater were for irrigation purposes.

  18. Swimming in the USA: Beachgoer Characteristics and Health Outcomes at U.S. Marine and Freshwater Beaches

    EPA Science Inventory

    Swimming in lakes and oceans is popular, but tittle is known about the demographic characteristics, behaviors, and health risks of beachgoers on a national level. Data from a prospective cohort study of beachgoers at multiple marine and freshwater beaches in the USA were used to ...

  19. Pipeline corridors through wetlands - impacts on plant communities: Bayou Grand Cane, De Soto Parish, Louisiana. Topical report, August 1991--July 1993

    SciTech Connect

    Shem, L.M.; Zimmerman, R.E.; Hayes, D.; Van Dyke, G.D. |

    1994-12-01

    The goal of the Gas Research Institute Wetland Corridors Program is to document impacts of existing pipeline on the wetlands they traverse. To accomplish this goal, 12 existing wetland crossings were surveyed. These sites varied in elapsed time since pipeline construction, wetland type, pipeline installation techniques, and night of-way (ROW) management practices. This report presents the results of a survey conducted over the period of August 12-13, 1991, at the Bayou Grand Cane crossing in De Soto Parish, Louisiana, where a pipeline constructed three years prior to the survey crosses the bayou through mature bottomland hardwoods. The sit was not seeded or fertilized after construction activities. At the time of sampling, a dense herb stratum (composed of mostly native species) covered the 20-m-wide ROW, except within drainage channels. As a result of the creation of the ROW, new habitat was created, plant diversity increased, and forest habitat became fragmented. The ROW must be maintained at an early stage of succession to allow access to the pipeline however, impacts to the wetland were minimized by decreasing the width of the ROW to 20 m and recreating the drainage channels across the ROW. The canopy trees on the ROW`s edge shaded part of the ROW, which helped to minimize the effects of the ROW.

  20. NATIVE FRESHWATER FISH AND MUSSEL SPECIES RICHNESS

    EPA Science Inventory

    These data represent predicted current distributions of all native freshwater fish and freshwater mussels in the Middle-Atlantic region. The data are available for both 8-digit HUCs and EMAP hexagons and represent total species counts for each spatial unit.

  1. Effects of Pollution on Freshwater Fish.

    ERIC Educational Resources Information Center

    Brungs, W. A.; And Others

    1978-01-01

    Presents a literature review of the effects of pollution on freshwater fish, covering publications of 1976-77. This review includes: (1) water quality; (2) pesticide pollutants; (3) chemical pollutants; (4) miscellaneous pollutants; and (5) physical factors of pollution on freshwater fish. A list of 338 references is also presented. (HM)

  2. Freshwater Ecology. LC Science Tracer Bullet.

    ERIC Educational Resources Information Center

    Niskern, Diana, Comp.

    Freshwater ecosystems include lakes, ponds, streams, rivers, and certain types of wetlands. This literature and resources guide is not intended to be a comprehensive bibliography on freshwater ecology; the guide is designed--as the name of the series implies--to put the reader or student "on target." Other literature guides related to freshwater…

  3. Freshwater Biological Traits Database (Final Report)

    EPA Science Inventory

    Cover of the <span class=Freshwater Biological Traits Database Final Report"> This final report discusses the development of a database of freshwater biolo...

  4. Why are freshwater fish so threatened?

    USGS Publications Warehouse

    Closs, Gerard P.; Angermeier, Paul; Darwall, William R.T.; Balcombe, Stephen R.

    2015-01-01

    Understanding why so many freshwater fish species are threatened requires some understanding of their biology, diversity, distribution, biogeography and ecology, but also some appreciation of the social, economic and political forces that are causing humans to destroy the natural ecosystems upon which we all ultimately depend. To begin to understand the diversity of freshwater fishes, we first need to consider the processes that generated and continue to sustain the diversity of species we see today. Based on an understanding of how freshwater fish diversity is generated and sustained, we consider how vulnerable or resilient various freshwater fishes are to the range of anthropogenic impacts that impinge on freshwater ecosystems. Finally, we discuss how social, political and economic drivers influence human impacts on natural systems, and the changes needed to current models of development that can lead to a sustainable future for humans and the diverse range of freshwater fish species with which we share our planet. The aim of this chapter is to provide an overview of the key issues and threats driving the declines in freshwater fish diversity identified in Chapter 1; subsequent chapters provide more detail on the key issues and address our options for developing a sustainable future for freshwater fishes.

  5. Freshwater for resilience: a shift in thinking.

    PubMed Central

    Folke, Carl

    2003-01-01

    Humanity shapes freshwater flows and biosphere dynamics from a local to a global scale. Successful management of target resources in the short term tends to alienate the social and economic development process from its ultimate dependence on the life-supporting environment. Freshwater becomes transformed into a resource for optimal management in development, neglecting the multiple functions of freshwater in dynamic landscapes and its fundamental role as the bloodstream of the biosphere. The current tension of these differences in worldview is exemplified through the recent development of modern aquaculture contrasted with examples of catchment-based stewardship of freshwater flows in dynamic landscapes. In particular, the social and institutional dimension of catchment management is highlighted and features of social-ecological systems for resilience building are presented. It is concluded that this broader view of freshwater provides the foundation for hydrosolidarity. PMID:14728796

  6. Pathogenic agents in freshwater resources

    NASA Astrophysics Data System (ADS)

    Geldreich, Edwin E.

    1996-02-01

    Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and should not be ignored. The range of infected individuals within a given warm-blooded animal group (humans included) may range from 1 to 25%. Survival times for pathogens in the water environment may range from a few days to as much as a year (Ascaris, Taenia eggs), with infective dose levels varying from one viable cell for several primary pathogenic agents to many thousands of cells for a given opportunistic pathogen.As pathogen detection in water is complex and not readily incorporated into routine monitoring, a surrogate is necessary. In general, indicators of faecal contamination provide a positive correlation with intestinal pathogen occurrences only when appropriate sample volumes are examined by sensitive methodology.Pathways by which pathogens reach susceptible water users include ingestion of contaminated water, body contact with polluted recreational waters and consumption of salad crops irrigated by polluted freshwaters. Major contributors to the spread of various water-borne pathogens are sewage, polluted surface waters and stormwater runoff. All of these contributions are intensified during periods of major floods. Several water-borne case histories are cited as examples of breakdowns in public health protection related to water supply, recreational waters and the consumption of contaminated salad crops. In the long term, water resource management must focus on pollution prevention from point sources of waste discharges and the spread of pathogens in watershed stormwater runoff.

  7. Streamflow and nutrient data for the Yazoo River below Steele Bayou near Long Lake, Mississippi, 1996-2000

    USGS Publications Warehouse

    Runner, Michael S.; Turnipseed, D. Phil; Coupe, Richard H.

    2002-01-01

    Increased nutrient loading to the Gulf of Mexico from off-continent flux has been identified as contributing to the increase in the areal extent of the low dissolved-oxygen zone that develops annually off the Louisiana and Texas coast. The proximity of the Yazoo River Basin in northwestern Mississippi to the Gulf of Mexico, and the intensive agricultural activities in the basin have led to speculation that the Yazoo River Basin contributes a disproportionate amount of nitrogen and phosphorus to the Mississippi River and ultimately to the Gulf of Mexico. An empirical measurement of the flux of nitrogen and phosphorus from the Yazoo Basin has not been possible due to the hydrology of the lower Yazoo River Basin. Streamflow for the Yazoo River below Steele Bayou is affected by backwater from the Mississippi River. Flow at the gage is non-uniform and varying, with bi-directional and reverse flows possible. Streamflow was computed by using remote sensing and acoustic and conventional discharge and velocity measurement techniques. Streamflow from the Yazoo River for the 1996-2000 period accounted for 2.8 percent of the flow of the Mississippi River for the same period. Water samples from the Yazoo River were collected from February 1996 through December 2000 and were analyzed for total nitrogen, nitrate, total phosphorus, and orthophosphorus as part of the U.S. Geological Survey National Water-Quality Assessment Program. These data were used to compute annual loads of nitrogen and phosphorus discharged from the Yazoo River for the period 1996-2000. Annual loads of nitrogen and phosphorus were calculated by two methods. The first method used multivariate regression and the second method multiplied the mean annual concentration by the total annual flow. Load estimates based on the product of the mean annual concentration and the total annual flow were within the 95 percent confidence interval for the load calculated by multivariate regression in 10 of 20 cases. The Yazoo

  8. The mesoscale and regional freshwater flux

    NASA Astrophysics Data System (ADS)

    Gordon, A. L.; Giulivi, C. F.

    2012-12-01

    The closer we look at the ocean, with improved instrumentation and models, the less it looks like the familiar 'textbook' view of overly smoothed maps of SST and SSS, with ocean scale circulation gyres, and more of a jumble of a westward parade of mesoscale features. The question arises: what role does the mesoscale play in compensating the air-sea flux of heat and freshwater? Here we focus on the freshwater balance within the salty North Atlantic subtropics regime, where the annual evaporation minus precipitation (E-P) is over 1 m/year. A traditional view is that the required quasi-steady state ocean freshwater inflow is derived from the wind-driven circulation and the associated shallow meridional overturning circulation. Here we evaluate if the mesoscale 'eddy' field, may stir into the subtropical regime a significant share of the needed freshwater. The Voluntary Observing Ships (VOS) data provide an overview of the SSS seasonal cycle of the Atlantic subtropical regime. While E-P is always positive, greater in January-July, minimum in October, the SSS displays a maximum in October, minimum occurs in April. It is hypothesized that the lower SSS of the winter/spring period marks increased winter freshwater flux by meso-scale activity. While the eddy freshwater flux can be estimated from the Rapid thermohaline and velocity data sections near 24.5°N, it is the meridional convergence of the eddy freshwater flux that compensates the regional E-P. We use the SODA output, which assimilates the VOS and Rapid data, to estimate the eddy freshwater flux convergence. Our preliminary assessment is that the eddy flux convergence does play a major role in closing the seasonal freshwater cycle of the North Atlantic surface layer.

  9. Conservation and protection of Georgia's freshwater wetlands

    SciTech Connect

    Turner, M.J.J.

    1989-01-01

    Georgia's freshwater wetlands are a valuable natural resource. Despite this fact, they are vanishing at an alarming rate. One objective of the research presented in this dissertation was to try to determine why freshwater wetlands have been so little esteemed historically that their destruction has until lately drawn little attention. In addition, it was hoped that this research would lead to conclusions about the extent of Georgia's freshwater wetlands and the status of their conservation and protection. A further goal of the study was to generate ideas about how better to protect this resource, and to examine policy issues that must be addressed in association with the problem. Interest in freshwater wetlands is part of a continuum of interests and events associated with environmental awareness that has its roots in the late 1800's and early 1900's. An understanding of the history of the environmental movement and the maturation of environmental philosophy provides needed background against which the issues associated with preservation of freshwater wetlands must be viewed. The first two chapters are thus devoted to an exploration of the history of environmental awareness and activism. In the third chapter, historical material about freshwater wetlands in the, US is presented. The final section is dedicated to a discussion of freshwater wetlands in Georgia. Georgia's boundaries encompass five physiographic provinces. Freshwater wetlands are found in all of these regions, but the type of wetland varies among them. In the northern part of the state, freshwater wetlands are scarce, but in the southern half of the state they are so common as to be considered a dominant feature of the landscape. Among the threats to Georgia's wetlands are urban development, agricultural conversion, impoundment, and pollution.

  10. Contamination of the freshwater ecosystem by pesticides

    USGS Publications Warehouse

    Cope, Oliver B.

    1966-01-01

    A large part of our disquieting present-day pesticide problem is intimately tied to the freshwater ecosystem. Economic poisons are used in so many types of terrain to control so many kinds of organisms that almost all lakes and streams are likely to be contaminated. In addition to accidental contamination many pesticides are deliberately applied directly to fresh waters for suppression of aquatic animals or plants. The problem is intensified because of the extreme susceptibility of freshwater organisms. The complexity of freshwater environments and their variety makes it difficult to comprehend the total effect of pesticides.

  11. Biodiversity Prospecting.

    ERIC Educational Resources Information Center

    Sittenfeld, Ana; Lovejoy, Annie

    1994-01-01

    Examines the use of biodiversity prospecting as a method for tropical countries to value biodiversity and contribute to conservation upkeep costs. Discusses the first agreement between a public interest organization and pharmaceutical company for the extraction of plant and animal materials in Costa Rica. (LZ)

  12. 40 CFR 35.1605-3 - Publicly owned freshwater lake.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Publicly owned freshwater lake. 35.1605... Owned Freshwater Lakes § 35.1605-3 Publicly owned freshwater lake. A freshwater lake that offers public... maintaining the public access and recreational facilities of this lake or other publicly owned...

  13. 40 CFR 35.1605-3 - Publicly owned freshwater lake.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Publicly owned freshwater lake. 35.1605... Owned Freshwater Lakes § 35.1605-3 Publicly owned freshwater lake. A freshwater lake that offers public... maintaining the public access and recreational facilities of this lake or other publicly owned...

  14. 40 CFR 35.1605-3 - Publicly owned freshwater lake.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Publicly owned freshwater lake. 35.1605... Owned Freshwater Lakes § 35.1605-3 Publicly owned freshwater lake. A freshwater lake that offers public... maintaining the public access and recreational facilities of this lake or other publicly owned...

  15. 40 CFR 35.1605-3 - Publicly owned freshwater lake.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Publicly owned freshwater lake. 35.1605... Owned Freshwater Lakes § 35.1605-3 Publicly owned freshwater lake. A freshwater lake that offers public... maintaining the public access and recreational facilities of this lake or other publicly owned...

  16. 40 CFR 35.1605-3 - Publicly owned freshwater lake.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Publicly owned freshwater lake. 35.1605... Owned Freshwater Lakes § 35.1605-3 Publicly owned freshwater lake. A freshwater lake that offers public... maintaining the public access and recreational facilities of this lake or other publicly owned...

  17. Adaptive diversity: hormones and metabolism in freshwaters.

    PubMed

    Laudet, Vincent

    2010-12-01

    Genes underlying the evolution of morphological traits have recently been identified in a number of model species. In the stickleback, the metabolic adaptations to a freshwater habitat have now been linked to a well-known hormonal system. PMID:21145015

  18. EFFECTS OF POLLUTION ON FRESHWATER FISH

    EPA Science Inventory

    An extensive literature review is presented which is concerned with the effects of pollutants (metals, pesticides, detergents, industrial wastes) on freshwater fish; chemical and biological methods for identifying and determining the effects of such pollutants; and the effects of...

  19. Freshwater resources of Big Pine Key, Florida

    USGS Publications Warehouse

    Hanson, Chris E.

    1980-01-01

    The principal freshwater-bearing unit underlying Big Pine Key, Fla, is a layer of oolitic limestone averaging 19 feet in thickness. The freshwater exists in two separate lenses, one in the northern half of the island and one in the southern half. The slightly larger north lens is separated from the south lens by a low-lying land area 1 to 3 feet above mean sea level. The lenses float on saltwater in the aquifer and are affected by tidal fluctuations. The areal and depth configuration of the lenses fluctuate in response to rainfall, evapotranspiration, lateral and vertical losses, and pumpage from local wells. The lenses are not a major source of freshwater. Only a small amount of the freshwater in the lenses can be removed before saltwater intrusion will occur. (USGS)

  20. Estimated freshwater withdrawals in Washington, 2010

    USGS Publications Warehouse

    Lane, Ron C.; Welch, Wendy B.

    2015-01-01

    The amount of public- and self-supplied water used for domestic, irrigation, livestock, aquaculture, industrial, mining, and thermoelectric power was estimated for state, county, and eastern and western regions of Washington during calendar year 2010. Withdrawals of freshwater for offstream uses were estimated to be about 4,885 million gallons per day. The total estimated freshwater withdrawals for 2010 was approximately 15 percent less than the 2005 estimate because of decreases in irrigation and thermoelectric power withdrawals.

  1. Future freshwater demands in the Arctic

    NASA Astrophysics Data System (ADS)

    White, D.; Strang, E. T.; Hinzman, L.; Alessa, L.; Kliskey, A.

    2004-12-01

    The overall objective of our research is to understand how humans rely on freshwater at local and regional scales in the Arctic, how these dependencies have changed in the recent past, and how they are likely to change in the future. This study will take place on the Seward Peninsula where climate induced changes in the hydrologic cycle are already being observed. This presentation will describe the human dependencies on freshwater in the Arctic. In particular, we will discuss the effects of inadequate quantity or quality of freshwater on Arctic inhabitants. The freshwater used by humans in the Arctic for drinking, cooking, and washing is derived in many cases from surface water, such as lakes and streams. Since the surface water frozen 6-9 months of the year in the Arctic, communities that rely on rivers and lakes must treat and store large volumes of water for use during winter. The stored water must be heated throughout the winter and distributed on an as-needed basis. Unfortunately, when not enough water can be gathered in the summer or stored in the winter, the entire community may be without freshwater. During these months, water must be collected by individuals from ice, snow, and rain. Collecting water during breakup can be dangerous. River ice is rotten, there is too little snow for snow mobiles, and the tundra is too soft all terrain vehicles. While the state of Alaska and Federal programs are making progress towards developing sustainable water sources for Alaska's Arctic communities, freshwater remains a precious commodity. Communities throughout the Arctic, including Canada and Russia, have similar problems with obtaining and purifying freshwater. As climate induced changes are being observed in the Arctic, the threat to the freshwater resource is now a greater concern than ever. This study is being funded under the NSF Arctic System Science Program, Human Dimensions of the Arctic (OPP-0328686).

  2. National Water-Quality Assessment Program; summary of pesticide data collected on East Fork Double Bayou, near Anahuac, Texas, March to September 1994

    USGS Publications Warehouse

    U.S. Geological Survey

    1995-01-01

    The Trinity River Basin study-unit assessment began in October 1991, with 2 years dedicated to planning, analyzing existing information, and designing data-collection networks, surveys, and studies. Then, a 3-year intensive data-collection program was initiated. The assessment followed guidelines provided by the National Water-Quality Assessment (NAWQA) Program National Synthesis team and considered suggestions made by the study unit's liaison committee. One of the issues selected for study concerned the quality of runoff in the coastal prairie. The study includes collecting streamflow, water-quality and watershed data on three streams, each representing watersheds in different parts of the coastal prairie. This fact sheet presents a summary of the pesticide data collected on East Fork Double Bayou from March to September 1994.

  3. Final report for the geothermal well site restoration and plug and abandonment of wells: DOE Pleasant Bayou test site, Brazoria County, Texas

    SciTech Connect

    Rinehart, Ben N.; Seigel, Ben H.

    1994-03-13

    For a variety of reasons, thousands of oil and gas wells have been abandoned in the Gulf Coast Region of the United States. Many of these wells penetrated geopressured zones whose resource potential for power generation was undervalued or ignored. The U.S. Department of Energy (DOE) Geopressured-Geothermal Research Program was chartered to improve geothermal technology to the point where electricity could be commercially produced from a substantial number of geopressured resource sites. This research program focused on relatively narrow technical issues that are unique to geopressured resources such as the ability to predict reservoir production capacity based on preliminary flow tests. Three well sites were selected for the research program. These are the Willis Hulin and Gladys McCall sites in Louisiana, and the Pleasant Bayou site in Texas. The final phase of this research project consists of plug and abandonment (P&A) of the wells and site restoration.

  4. Environmental baseline monitoring in the area of general crude oil - Department of Energy Pleasant Bayou Number 2: a geopressured geothermal test well, 1979. Annual report, Volume I

    SciTech Connect

    Gustavson, T.C.; Howard, R.C.; McGookey, D.

    1980-01-01

    A program to monitor baseline air and water quality, subsidence, microseismic activity, and noise in the vicinity of Brazoria County geopressured geothermal test wells, Pleasant Bayou No. 1 and No. 2, has been underway since March 1978. The initial report on environmental baseline monitoring at the test well contained descriptions of baseline air and water quality, a noise survey, an inventory of microseismic activity, and a discussion of the installation of a liquid tilt meter (Gustavson, 1979). The following report continues the description of baseline air and water quality of the test well site, includes an inventory of microseismic activity during 1979 with interpretations of the origin of the events, and discusses the installation and monitoring of a liquid tilt meter at the test well site. In addition, a brief description of flooding at the test site is presented.

  5. Human freshwater demand for economic activity and ecosystems in Taiwan.

    PubMed

    Ferng, Jiun-Jiun

    2007-12-01

    Freshwater is necessary to economic activity, and humans depend on goods and services generated by water-dependent ecosystems. However, national freshwater management usually focuses on direct use of domestic freshwater. With an increasing scarcity of freshwater, attention has turned to two indirect uses of freshwater by humans. The first indirect use is freshwater used by foreign countries when producing products for export. The second use is freshwater required by local ecosystems: human survival and development depend on goods and services generated in these ecosystems. This work adopted Taiwan as a case study. In addition to two widely recognized ecosystem freshwater demands, evapotranspiration and reversed river flow, this study suggests that freshwater is a constituent of some abiotic components, such as groundwater in aquifers, because excessive withdrawal has already caused significant land subsidence in Taiwan. Moreover, the estimated results show that Taiwan's net imports of freshwater through trade amounts to approximately 25% of its total freshwater use for economic production. Integrating industrial policy, trade policy, and national freshwater management is a useful approach for developing strategies to limit the growing use of freshwater in Taiwan. Policy implications are then developed by further analyzing withdrawal sources of freshwater (domestic and foreign) for supporting economic production in Taiwan and identifying the factors (domestic final demand and export) driving freshwater-intensive products. PMID:17899249

  6. Human Freshwater Demand for Economic Activity and Ecosystems in Taiwan

    NASA Astrophysics Data System (ADS)

    Ferng, Jiun-Jiun

    2007-12-01

    Freshwater is necessary to economic activity, and humans depend on goods and services generated by water-dependent ecosystems. However, national freshwater management usually focuses on direct use of domestic freshwater. With an increasing scarcity of freshwater, attention has turned to two indirect uses of freshwater by humans. The first indirect use is freshwater used by foreign countries when producing products for export. The second use is freshwater required by local ecosystems: human survival and development depend on goods and services generated in these ecosystems. This work adopted Taiwan as a case study. In addition to two widely recognized ecosystem freshwater demands, evapotranspiration and reversed river flow, this study suggests that freshwater is a constituent of some abiotic components, such as groundwater in aquifers, because excessive withdrawal has already caused significant land subsidence in Taiwan. Moreover, the estimated results show that Taiwan’s net imports of freshwater through trade amounts to approximately 25% of its total freshwater use for economic production. Integrating industrial policy, trade policy, and national freshwater management is a useful approach for developing strategies to limit the growing use of freshwater in Taiwan. Policy implications are then developed by further analyzing withdrawal sources of freshwater (domestic and foreign) for supporting economic production in Taiwan and identifying the factors (domestic final demand and export) driving freshwater-intensive products.

  7. Freshwater Commercial Bycatch: an Understated Conservation Problem

    SciTech Connect

    Raby, Graham D.; Colotelo, Alison HA; Blouin-Demers, Gabriel; Cooke, Steven J.

    2011-04-01

    Commercial fisheries bycatch in marine systems has been regarded as a global conservation concern by environmental groups, scientists, government, and the public for decades. Fortunately, some headway has been made to mitigate the negative impacts of bycatch in marine environments. In a survey of the literature, we found that despite freshwater commercial fisheries yields comprising 11% of the global commercial catch, bycatch research focusing on freshwater commercial fisheries represented only {approx}3% of the total bycatch literature. This paucity of research is particularly alarming given that freshwater animals and habitats are some of the world's most imperiled. The limited inland bycatch literature that does exist includes examples of population declines attributed to commercial bycatch (e.g., freshwater dolphins in the Yangtze River in China) and illustrates that in some systems bycatch can be substantial (e.g., lake trout bycatch in the Laurentian Great Lakes). Encouraging results from the marine realm can serve as models for bycatch research in freshwater, and lead to measurable gains in conservation of freshwater ecosystems. We summarize existing work on inland bycatch in an effort to draw attention to this understated and understudied conservation problem.

  8. Commissioned Review. Carbon: freshwater plants

    USGS Publications Warehouse

    Keeley, J.E.; Sandquist, D.R.

    1992-01-01

    δ13C values for freshwater aquatic plant matter varies from −11 to −50‰ and is not a clear indicator of photosynthetic pathway as in terrestrial plants. Several factors affect δ13C of aquatic plant matter. These include: (1) The δ13C signature of the source carbon has been observed to range from +1‰ for HCO3− derived from limestone to −30‰ for CO2 derived from respiration. (2) Some plants assimilate HCO3−, which is –7 to –11‰ less negative than CO2. (3) C3, C4, and CAM photosynthetic pathways are present in aquatic plants. (4) Diffusional resistances are orders of magnitude greater in the aquatic environment than in the aerial environment. The greater viscosity of water acts to reduce mixing of the carbon pool in the boundary layer with that of the bulk solution. In effect, many aquatic plants draw from a finite carbon pool, and as in terrestrial plants growing in a closed system, biochemical discrimination is reduced. In standing water, this factor results in most aquatic plants having a δ13C value similar to the source carbon. Using Farquhar's equation and other physiological data, it is possible to use δ13C values to evaluate various parameters affecting photosynthesis, such as limitations imposed by CO2 diffusion and carbon source.

  9. Global estimation of freshwater fluxes and freshwater oceanic transport from satellite data

    SciTech Connect

    Gautier, C.; Peterson, P.; Jones, C.

    1996-12-01

    The exchange of moisture and heat fluxes across the ocean-atmosphere interface exerts a strong influence on the oceanic and atmospheric circulations, and therefore on the maintenance of the climate system equilibrium. Observational measurements of these fluxes over large areas of the ocean`s surface are limited by the lack of in-situ data. This paper reports research efforts to estimate the freshwater budget and freshwater oceanic transport using remotely sensed data. Six years (1988--1993) of surface evaporation estimated with satellite and in-situ data re combined with satellite-derived precipitation to compute the freshwater budget and freshwater oceanic transport. The interannual variability of the freshwater budget and oceanic transport eliminates are examined for two contrasting events: the La Nina of 1988--89 and the El Nino condition during 1991--92, one of the longest El Nino episodes on record. Possible implications for future climate change are discussed.

  10. Prospective Optimization

    PubMed Central

    Sejnowski, Terrence J.; Poizner, Howard; Lynch, Gary; Gepshtein, Sergei; Greenspan, Ralph J.

    2014-01-01

    Human performance approaches that of an ideal observer and optimal actor in some perceptual and motor tasks. These optimal abilities depend on the capacity of the cerebral cortex to store an immense amount of information and to flexibly make rapid decisions. However, behavior only approaches these limits after a long period of learning while the cerebral cortex interacts with the basal ganglia, an ancient part of the vertebrate brain that is responsible for learning sequences of actions directed toward achieving goals. Progress has been made in understanding the algorithms used by the brain during reinforcement learning, which is an online approximation of dynamic programming. Humans also make plans that depend on past experience by simulating different scenarios, which is called prospective optimization. The same brain structures in the cortex and basal ganglia that are active online during optimal behavior are also active offline during prospective optimization. The emergence of general principles and algorithms for goal-directed behavior has consequences for the development of autonomous devices in engineering applications. PMID:25328167

  11. Effects of Pollution on Freshwater Organisms.

    PubMed

    Choudri, B S; Baawain, Mahad

    2016-10-01

    This review includes works published in the general scientific literature during 2015 on the effects of anthropogenic pollutants on freshwater organisms. It begins with two broad sections: research reviews and broad field studies and surveys. This is followed by reviews of research categorized in sections to reflect the pollutant class. These sections include wastewater, stormwater and non-point source pollution, nutrients, sediment cap materials and suspended clays, botanical extracts, surfactants, metals, persistent organic pollutants, pharmaceuticals, endocrine disruptors, pesticides, petroleum hydrocarbons and polycyclic aromatic hydrocarbons (PAHs), ionic liquids, and nanomaterials. The final section includes works describing innovations in the field of freshwater pollution research. PMID:27620107

  12. FRESHWATER INFLOWS: WATER FOR HEALTHY ESTUARIES CONFERENCE (MX96476507

    EPA Science Inventory

    The grantee will hold an interstate workshop on Freshwater Inflow issues in the Gulf of Mexico coastal region. The conference will identify water management questions to be addressed regarding providing freshwater inflows to estuaries, update participants on the current scientif...

  13. Dispersion Of Crude Oil And Petroleum Products In Freshwater

    EPA Science Inventory

    The objective of this research was to investigate the relationship between dispersion effectiveness in freshwater and the surfactant composition for fresh and weathered crude oil. Although limited research on the chemical dispersion of crude oil and petroleum products in freshwat...

  14. Continental Shelf Freshwater Water Resources and Enhanced Oil Recovery By Low Salinity Water Flooding

    NASA Astrophysics Data System (ADS)

    Person, M. A.; Morrow, N.; Wilson, J. L.

    2014-12-01

    This study investigates the prospects of utilizing offshore freshwater in continental shelf oil production. Petroleum engineers have recently shown that tertiary water floods using freshwater can enhance oil recovery by as much as 18% (Morrow and Buckley, 2011). Hydrogeologists recently estimated that up to 5x105 km3of fresh to brackish water are sequestered in shallow ( < 500 m) permeable sands and carbonate reservoirs within 80 km of the present-day coastline around the world (Post et al., 2013). Most of the offshore freshwater was emplaced during the Pleistocene during periods of sea level low stands and when ice sheets over ran passive margins at high latitudes. We have analyzed a series of continental shelf cross sections from around the world estimating the average freshwater volume emplaced with distance offshore. We compare the distribution of fresh-brackish water with distance from the coastline to oil platform locations in order to assess the economic viability of this energy-water nexus. We also discuss a project that is currently underway within the North Sea (Clair Ridge) to field validate this concept. We present a series of variable-density groundwater flow and solute transport simulations that are intended to assess how long freshwater resources could be produced in an offshore environment using horizontal drilling technologies before seawater invades the well. We considered a 100m thick freshwater reservoir sandwiched between two 200-300m thick confining units. We pumped the horizontal well at a rate of 5.4 m3/day (1 gpm per meter of well). The resulting drawdown was less than 5 m at the well head (r=0.15 m). For a 1000 m long horizontal well, this resulted in the production of 5455 m3/day of fresh water (over 34,000 barrels per day). Concentrations increased at the wellhead by about 5000 mg/l after 20 years of continuous pumping using a reservoir permeability of 10-13 m2. This simulation demonstrates that where freshwater is available it is likely

  15. 40 CFR 35.1605-2 - Freshwater lake.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Freshwater lake. 35.1605-2 Section 35... STATE AND LOCAL ASSISTANCE Cooperative Agreements for Protecting and Restoring Publicly Owned Freshwater Lakes § 35.1605-2 Freshwater lake. Any inland pond, reservoir, impoundment, or other similar body...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. TOXICITY OF SYNTHETIC PYRETHROIDS TO FRESHWATER INVERTEBRATES

    EPA Science Inventory

    This report reviews the laboratory toxicity data on freshwater target and nontarget invertebrate s exposed to pyrethroids and evaluates the state of the data. Early in their development, yrethroids were shown to be highly effective insecticides gainst mosquitoes, blackflies and c...

  1. Mathematical Explorations: Freshwater Scarcity: A Proportional Representation

    ERIC Educational Resources Information Center

    King, Alessandra

    2014-01-01

    Middle school students' mathematical understanding benefits from connecting mathematics to other content areas in the curriculum. This month's activity explores the issue of the scarcity of freshwater, a natural resource (activity sheets are included). This activity concentrates on the critical areas mentioned in the Common Core State…

  2. Freshwater Biological Traits Database (External Review Draft)

    EPA Science Inventory

    This draft report discusses the development of a database of freshwater biological traits. The database combines several existing traits databases into an online format. The database is also augmented with additional traits that are relevant to detecting climate change-related ef...

  3. Freshwater savings from marine protein consumption

    NASA Astrophysics Data System (ADS)

    Gephart, Jessica A.; Pace, Michael L.; D'Odorico, Paolo

    2014-01-01

    Marine fisheries provide an essential source of protein for many people around the world. Unlike alternative terrestrial sources of protein, marine fish production requires little to no freshwater inputs. Consuming marine fish protein instead of terrestrial protein therefore represents freshwater savings (equivalent to an avoided water cost) and contributes to a low water footprint diet. These water savings are realized by the producers of alternative protein sources, rather than the consumers of marine protein. This study quantifies freshwater savings from marine fish consumption around the world by estimating the water footprint of replacing marine fish with terrestrial protein based on current consumption patterns. An estimated 7 600 km3 yr-1 of water is used for human food production. Replacing marine protein with terrestrial protein would require an additional 350 km3 yr-1 of water, meaning that marine protein provides current water savings of 4.6%. The importance of these freshwater savings is highly uneven around the globe, with savings ranging from as little as 0 to as much as 50%. The largest savings as a per cent of current water footprints occur in Asia, Oceania, and several coastal African nations. The greatest national water savings from marine fish protein occur in Southeast Asia and the United States. As the human population increases, future water savings from marine fish consumption will be increasingly important to food and water security and depend on sustainable harvest of capture fisheries and low water footprint growth of marine aquaculture.

  4. Toxicity of vanadium to different freshwater organisms

    SciTech Connect

    Beusen, J.M.; Neven, B.

    1987-08-01

    The aim of this study is to determine the acute and subchronic toxicity of vanadium for various species of freshwater fish. The long-term toxicity and the effect of vanadium on the reproduction of Daphnia magna is also evaluated and compared with the toxicity of other metals.

  5. Effects of Pollution on Freshwater Invertebrates.

    ERIC Educational Resources Information Center

    Buikema, A. L., Jr.; Herricks, E. E.

    1978-01-01

    Presents a literature review of the effects of pollution on freshwater invertebrates, covering publications of 1976-77. Some of the areas covered are: (1) toxicant effects on invertebrates; (2) microcosm and community effects, and (3) biological control of aquatic life. A list of 123 references is also presented. (HM)

  6. Tetanus after envenomations caused by freshwater stingrays.

    PubMed

    Torrez, Pasesa P Q; Quiroga, Mariana M; Said, Renato; Abati, Paulo A M; França, Francisco O S

    2015-04-01

    Injuries caused by freshwater stingray are common in several regions of South America, although they are underreported. The riverside inhabitants are the main victims in the Amazonian and Midwest regions of South America. The fishermen are injured mainly in the new focus of colonization of the rivers by freshwater stingrays. With the increasing population in these regions, where freshwater stingrays are found, there has been a significant increase in injuries within the general population. The highest increase occurred among tourists from other regions, where these animals are not known, when visiting these areas. The envenomations from the stingray causes prolonged and intense pain, both local and regionally. Generally these are associated with other local inflammatory manifestations, such as swelling and erythema. The injury often progresses to necrosis and it is considered potentially tetanogenic. A secondary infection is also a frequent local complication and most frequently is caused by Aeromonas species, usually Aeromonas hydrophila. Herein we report the first 2 cases of tetanus after freshwater stingray injuries: a 51-year-old men who had tetanus and recovered without sequel and the second a 67-year-old men who had severe tetanus and a deep, necrotizing soft-tissue infection with sepsis, septic shock and evolution to death. PMID:25576234

  7. In Brief: Europe's freshwater fish threatened

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2007-11-01

    Two hundred of Europe's 522 freshwater fish species are threatened with extinction and 12 are already extinct, according to the Handbook of European Freshwater Fishes, published in collaboration with the World Conservation Union (IUCN) and released on 1 November 2007. IUCN notes that the main threats to fish species stem from development and population growth and include water withdrawals, large dams, and inappropriate fisheries management that has led to overfishing and the introduction of alien species. Authors Maurice Kottelat, former president of the European Ichthyological Society, and Jörg Freyhof, scientist from Leibniz Institute of Freshwater Ecology, noted that fish conservation should be managed by agencies in charge of conservation, and not as a crop by agencies in charge of agriculture. William Darwall, senior program officer with IUCN's Species Program, said the species ``are critical to the freshwater ecosystems upon which we do depend, such as for water purification and flood control.'' For more information, visit the Web site: http://www.iucn.org.

  8. DIBUTYLPHTHALATE DEGRADATION IN ESTUARINE AND FRESHWATER SITES

    EPA Science Inventory

    Biotic and abiotic degradation of di-n-butylphthalate (DBP) in water and sediment/water systems from six different sites was investigated under laboratory conditions. Water and underlying sediment were collected from freshwater and estuarine sites in Florida, Mississippi, and Lou...

  9. FRESHWATER SNAILS (MOLLUSCA: GASTROPODA) OF NORTH AMERICA

    EPA Science Inventory

    Freshwater gastropod mollusks are represented in North America (north of Mexico) by 15 families, 78 genera and, as treated in this manual, 499 species. They are grouped into two large subclasses, the gill-breathing, operculated Prosobranchia and the lung-breathing, non-operculate...

  10. Effects of pollution on freshwater invertebrates

    SciTech Connect

    Buikema

    1982-06-01

    The biological effects of acid rain, chlorination, heavy metals and other forms of pollution on freshwater invertebrates are examined in this review. Several methods for evaluating chronic toxicity to pesticide residues and synthetic fuels components are reviewed. The effects of pollutants is reviewed in detail for cladocera, amphipods, isopods, decapods, aquatic insects, molluscs, worms, and protozoa.(KRM)

  11. Macrophytes: Freshwater Forests of Lakes and Rivers.

    ERIC Educational Resources Information Center

    McDermid, Karla J.; Naiman, Robert J.

    1983-01-01

    Physical, chemical, and biological effects on macrophytes (aquatic plants) on the freshwater ecosystem are discussed. Research questions and issues related to these organisms are also discussed, including adaptations for survival in a wet environment, ecological consequences of large-scale macrophyte eradication, seasonal changes in plant…

  12. 2008 NWFSC Tidal Freshwater Genetics Results

    SciTech Connect

    David Teel

    2009-05-01

    Genetic Analysis of Juvenile Chinook Salmon for inclusion in 'Ecology of Juvenile Salmon in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, Lower Columbia River, 2008. Annual Report to Bonneville Power Administration, Contract DE-AC05-76RL01830.'

  13. Tulane/Xavier Center for Bioenvironmental Research; project: hazardous materials in aquatic environments; subproject: biomarkers and risk assessment in Bayou Trepagnier, LA

    SciTech Connect

    Ide, C.

    1996-12-31

    Tulane and Xavier Universities have singled out the environment as a major strategic focus for research and training for now and beyond the year 2000. the Tulane/Xavier Center for Bioenvironmental Research (CBR) was established in 1989 as the umbrella organization to coordinate environmental research at both universities. CBR projects funded by the DOE under the Hazardous Materials in Aquatic Environments grant are defining the following: (1) the complex interactions that occur during the transport of contaminants through wetlands environments, (2) the actual and potential impact of contaminants on ecological systems and health, (3) the mechanisms and new technologies through which these impacts might be remediated, and (4) new programs aimed at educating and training environmental workers of the future. The subproject described in this report, `Biomarkers and Risk Assessment in Bayou Trepagnier, LN`, is particularly relevant to the US Department of Energy`s Environmental Restoration and Waste Management program aimed at solving problems related to hazard monitoring and clean-up prioritization at sites with aquatic pollution problems in the DOE complex.

  14. Prospect redux

    NASA Technical Reports Server (NTRS)

    Jacquemoud, S.; Ustin, S. L.; Verdebout, J.; Schmuck, G.; Andreoli, G.; Hosgood, B.

    1995-01-01

    The remote estimation of leaf biochemical content from spaceborne platforms has been the subject of many studies aimed at better understanding of terrestrial ecosystem functioning. The major ecological processes involved in exchange of matter and energy, like photosynthesis, primary production, evaportranspiration, respiration, and decomposition can be related to plant properties e.g., chlorophyll, water, protein, cellulose and lignin contents. As leaves represent the most important plant surfaces interacting with solar energy, a top priority has been to relate optical properties to biochemical constituents. Two different approaches have been considered: first, statistical correlations between the leaf reflectance (or transmittance) and biochemical content, and second, physically based models of leaf scattering and absorption developed using the laws of optics. Recently reviewed by Verdebout et al., the development of models of leaf optical properties has resulted in better understanding of the interaction of light with plant leaves. Present radiative transfer models mainly use chlorophyll and/or water contents as input parameters to calculate leaf reflectance. Inversion of these models allows to retrieve these constituents from spectrophotometric measurements. Conel et al. recently proposed a two-stream Kubelka-Munk model to analyze the influence of protein, cellulose, lignin, and starch on leaf reflectance, but in fact, the estimation of leaf biochemistry from remote sensing is still an open question. In order to clarify it, a laboratory experiment associating visible/infrared spectra of plan leaves both with physical measurements and biochemical analyses was conducted at the Joint Research Center during the summer of 1993. This unique data set has been used to upgrade the PROSPECT model, by including leaf biochemistry.

  15. Ecotoxicology of selenium in freshwater systems.

    PubMed

    Maier, K J; Knight, A W

    1994-01-01

    The toxicology, environmental impacts and risk assessment of Se in freshwater systems are a high priority for research and regulatory agencies. However, understanding Se in freshwater systems is a challenging endeavor. The accurate risk assessment and determination of a water-quality criterion for any freshwater ecosystem are difficult for many reasons. First, the understanding of the structure and energy dynamics in ecosystems is limited. Second, knowledge of Se cycling and transformations in aquatic ecosystems is rudimentary. Third, the role of various environmental factors affecting its bioaccumulation, biotransformation, and toxicology in aquatic ecosystems is largely unknown. Fourth, the extrapolation and use of existing data in commonly used formulas for risk assessment and calculations of water quality criteria is difficult because of the demonstrated species differences in the bioaccumulation, metabolism, and tolerance of Se. There are many aspects of Se ecotoxicology that need to be addressed to develop more accurate environmental risk assessments and determine appropriate water-quality criteria to protect aquatic ecosystems. Studies evaluating the biochemical speciation of Se in aquatic ecosystems, and determination of the role of microbial communities in its cycling, bioaccumulation, transformation, transfer, and toxicity in aquatic systems, appear to be priorities for future research. These would include a broad exploration of Se effects on ecosystems, e.g., exposure regime, direct and indirect biologic effects, and ecosystem level effects. There are, however, ecological uncertainties that tend to confound such endeavors, e.g., insufficient data, extrapolation issues, and environmental stochasticity (Harwell and Harwell 1989). There are several concepts concerning the ecotoxicology of Se that can be stated. Elevated concentrations have degraded many freshwater ecosystems throughout the United States, and additional systems are expected to be affected as

  16. Mesozooplankton affinities in a recovering freshwater estuary

    NASA Astrophysics Data System (ADS)

    Chambord, Sophie; Maris, Tom; Colas, Fanny; Van Engeland, Tom; Sossou, Akoko-C.; Azémar, Frédéric; Le Coz, Maïwen; Cox, Tom; Buisson, Laetitia; Souissi, Sami; Meire, Patrick; Tackx, Michèle

    2016-08-01

    Water quality of the Scheldt estuary (Belgium/The Netherlands) has considerably improved in recent years, especially in the upstream, freshwater reaches. Within the zooplankton community, the copepod Eurytemora affinis, typically abundant in brackish water and quasi-absent from freshwater before 2007, has since substantially developed in the latter, where it now represents 90% of the crustacean mesozooplankton community. Simultaneously, cyclopoid copepod abundance has greatly decreased, while cladoceran abundance did not change. The study aim was: 1) to verify if the zooplankton community described for the period 2007-2009 by Mialet et al. (2011) has stabilized until present, and 2) to look for the environmental conditions favouring E. affinis development and causing changes in the upstream freshwater zooplankton community. The 2002-2012 temporal evolution of the zooplankton distribution at three stations in the upstream freshwater Scheldt estuary was analyzed. Water quality remained better after 2007 than before, and some factors revealed continuous improvement in annual mean concentrations (e.g. increase in O2, decrease in BOD5 and NH4sbnd N concentration). The increase in oxygen and the decrease in NH4sbnd N concentration, together with low discharge during summer were the main environmental factors explaining the development and timing of E. affinis in the upstream freshwater reach. In this reach, E. affinis maximal abundance is shifted to higher temperatures (summer) compared to its typical maximum spring abundance peak in the brackish zone of the Scheldt estuary and in most temperate estuaries. The changes in zooplankton community followed a temporal and spatial gradient induced by the spatio-temporal evolution of water quality improvement. The most downstream station (3) allowed E. affinis development (oxygen concentration > 4 mg L-1; NH4sbnd N concentration < 2 mg L-1, discharge (Q) < 50 m3 s-1) from 2007 onwards, and this station showed the highest E

  17. Freshwater aquatic plant biomass production in Florida

    SciTech Connect

    Reddy, K.R.; Sutton, D.L.; Bowes, G.

    1983-01-01

    About 8% (1.2 million ha) of the total surface area of Florida is occupied by freshwater. Many of these water bodies are eutrophic. Nutrients present in these water bodies can be potentially used to culture aquatic plants as a possible feedstock for methane production. This paper summarizes the results of known research findings on biomass production potential of freshwater aquatic plants in Florida and identifies key research needs to improve the quality and quantity of biomass yields. Among floating aquatic plants, biomass yield potential was in the order of water-hyacinth > water lettuce > pennywort > salvinia > duckweed > azolla. Pennywort, duckweed, and azolla appear to perform well during the cooler months compared to other aquatic plants. Among emergent plants, biomass yield potential was in the order of southern wild rice > cattails > soft rush > bulrush. Cultural techniques, nutrient management, and environmental factors influencing the biomass yields were discussed. 68 references.

  18. Freshwater biodiversity and aquatic insect diversification.

    PubMed

    Dijkstra, Klaas-Douwe B; Monaghan, Michael T; Pauls, Steffen U

    2014-01-01

    Inland waters cover less than 1% of Earth's surface but harbor more than 6% of all insect species: Nearly 100,000 species from 12 orders spend one or more life stages in freshwater. Little is known about how this remarkable diversity arose, although allopatric speciation and ecological adaptation are thought to be primary mechanisms. Freshwater habitats are highly susceptible to environmental change and exhibit marked ecological gradients. Standing waters appear to harbor more dispersive species than running waters, but there is little understanding of how this fundamental ecological difference has affected diversification. In contrast to the lack of evolutionary studies, the ecology and habitat preferences of aquatic insects have been intensively studied, in part because of their widespread use as bioindicators. The combination of phylogenetics with the extensive ecological data provides a promising avenue for future research, making aquatic insects highly suitable models for the study of ecological diversification. PMID:24160433

  19. Superhydrophobic resistance to dynamic freshwater biofouling inception.

    PubMed

    Krishnan, K Ghokulla; Malm, Peter; Loth, Eric

    2015-01-01

    Superhydrophobic nanotextured surfaces have gained increased usage in various applications due to their non-wetting and self-cleaning abilities. The aim of this study was to investigate nanotextured surfaces with respect to their resistance to the inception of freshwater biofouling at transitional flow conditions. Several coatings were tested including industry standard polyurethane (PUR), polytetrafluoroethylene (PTFE), capstone mixed polyurethane (PUR + CAP) and nanocomposite infused polyurethane (PUR + NC). Each surface was exposed to freshwater conditions in a lake at 4 m s(-1) for a duration of 45 min. The polyurethane exhibited the greatest fouling elements, in terms of both height and number of elements, with the superhydrophobic nanocomposite based polyurethane (PUR + NC) showing very little to no fouling. A correlation between the surface characteristics and the degree of fouling inception was observed. PMID:26618394

  20. Freshwater peat on the continental shelf

    USGS Publications Warehouse

    Emery, K.O.; Wigley, R.L.; Bartlett, A.S.; Rubin, M.; Barghoorn, E.S.

    1967-01-01

    Freshwater peats from the continental shelf off northeastern United States contain the same general pollen sequence as peats from ponds that are above sea level and that are of comparable radiocarbon ages. These peats indicate that during glacial times of low sea level terrestrial vegetation covered the region that is now the continental shelf in an unbroken extension from the adjacent land areas to the north and west.

  1. Freshwater peat on the continental shelf.

    PubMed

    Emery, K O; Wigley, R L; Bartlett, A S; Rubin, M; Barghoorn, E S

    1967-12-01

    Freshwater peats from the continental shelf off northeastern United States contain the same general pollen sequence as peats from ponds that are above sea level and that are of comparable radiocarbon ages. These peats indicate that during glacial times of low sea level terrestrial vegetation covered the region that is now the continental shelf in an unbroken extension from the adjacent land areas to the north and west. PMID:17801856

  2. Pesticides in Brazilian freshwaters: a critical review.

    PubMed

    Albuquerque, A F; Ribeiro, J S; Kummrow, F; Nogueira, A J A; Montagner, C C; Umbuzeiro, G A

    2016-07-13

    The widespread use of pesticides in agriculture can lead to water contamination and cause adverse effects on non-target organisms. Brazil has been the world's top pesticide market consumer since 2008, with 381 approved pesticides for crop use. This study provides a comprehensive literature review on the occurrence of pesticide residues in Brazilian freshwaters. We searched for information in official agency records and peer-reviewed scientific literature. Risk quotients were calculated to assess the potential risk posed to aquatic life by the individual pesticides based on their levels of water contamination. Studies about the occurrence of pesticides in freshwaters in Brazil are scarce and concentrated in few sampling sites in 5 of the 27 states. Herbicides (21) accounted for the majority of the substances investigated, followed by fungicides (11), insecticides (10) and plant growth regulators (1). Insecticides are the class of major concern. Brazil would benefit from the implementation of a nationwide pesticide freshwater monitoring program to support preventive, remediation and enforcement actions. PMID:27367607

  3. Urban growth, climate change, and freshwater availability

    PubMed Central

    McDonald, Robert I.; Green, Pamela; Balk, Deborah; Fekete, Balazs M.; Revenga, Carmen; Todd, Megan; Montgomery, Mark

    2011-01-01

    Nearly 3 billion additional urban dwellers are forecasted by 2050, an unprecedented wave of urban growth. While cities struggle to provide water to these new residents, they will also face equally unprecedented hydrologic changes due to global climate change. Here we use a detailed hydrologic model, demographic projections, and climate change scenarios to estimate per-capita water availability for major cities in the developing world, where urban growth is the fastest. We estimate the amount of water physically available near cities and do not account for problems with adequate water delivery or quality. Modeled results show that currently 150 million people live in cities with perennial water shortage, defined as having less than 100 L per person per day of sustainable surface and groundwater flow within their urban extent. By 2050, demographic growth will increase this figure to almost 1 billion people. Climate change will cause water shortage for an additional 100 million urbanites. Freshwater ecosystems in river basins with large populations of urbanites with insufficient water will likely experience flows insufficient to maintain ecological process. Freshwater fish populations will likely be impacted, an issue of special importance in regions such as India's Western Ghats, where there is both rapid urbanization and high levels of fish endemism. Cities in certain regions will struggle to find enough water for the needs of their residents and will need significant investment if they are to secure adequate water supplies and safeguard functioning freshwater ecosystems for future generations. PMID:21444797

  4. Monitoring Global Freshwater Resources with GRACE

    NASA Technical Reports Server (NTRS)

    Rodell, Matt; Famiglietti, Jay; Velicogna, Isabella; Swenson, Sean; Chambers, Don

    2011-01-01

    Freshwater resources include surface waters, groundwater, and seasonal snowpack. Given adequate ground based measurements, all of these can be monitored effectively, however, outside of the developed world such measurements often are not systematic and the data not centralized, and as a result reports of freshwater availability may be largely anecdotal. Even in the developed world it can be difficult to quantify changes in groundwater storage over large scales. Owing to its global coverage, satellite remote sensing has become a valuable tool for freshwater resources assessment. In particular, the Gravity Recovery and Climate Experiment (GRACE) has demonstrated an unequaled ability to monitor total terrestrial water storage including groundwater at regional to continental scales. In this presentation we will identify apparent trends in terrestrial water storage observed by GRACE over the past nine years and attempt to explain their origins and predict whether they are likely to continue. Trends in certain regions where groundwater extraction has significantly depleted aquifers, including northern India and California, will be discussed in detail.

  5. Vegetative community control of freshwater availability: Phoenix Islands case study

    NASA Astrophysics Data System (ADS)

    Engels, M.; Heinse, R.

    2014-12-01

    On small low islands with limited freshwater resources, terrestrial plant communities play a large role in moderating freshwater availability. Freshwater demands of vegetative communities are variable depending on the composition of the community. Hence, changes to community structure from production crop introductions, non-native species invasions, and climate change, may have significant implications for freshwater availability. Understanding how vegetative community changes impact freshwater availability will allow for better management and forecasting of limited freshwater supplies. To better understand these dynamics, we investigated three small tropical atolls in the Phoenix Island Protected Area, Kiribati. Despite their close proximity, these islands receive varying amounts of rainfall, are host to different plant communities and two of the islands have abandoned coconut plantations. Using electromagnetic induction, ground penetrating radar, soil samples, climate and satellite data, we present preliminary estimates of vegetative water demand for different tropical plant communities.

  6. Bayou virus detected in non-oryzomyine rodent hosts: an assessment of habitat composition, reservoir community structure, and marsh rice rat social dynamics.

    PubMed

    Holsomback, Tyla S; McIntyre, Nancy E; Nisbett, Richard A; Strauss, Richard E; Chu, Yong-Kyu; Abuzeineh, Alisa A; de la Sancha, Noé; Dick, Carl W; Jonsson, Colleen B; Morris, Brandon E L

    2009-06-01

    In the United States, Bayou virus (BAYV) ranks second only to Sin Nombre virus (SNV) in terms of hantavirus pulmonary syndrome (HPS) incidents, having been confirmed in cases from Texas and Louisiana since its discovery in 1994. This study on BAYV infection among sympatric, non-oryzomyine rodents ("spillover") in Freeport, TX, is the first to link patterns of hantavirus interspecific spillover with the spatiotemporal ecology of the primary host (marsh rice rat, Oryzomys palustris). Mark-recapture and/or harvest methods were employed from March 2002 through May 2004 in two macrohabitat types. Rodent blood samples were screened for the presence of IgG antibody to BAYV antigen by IFA after which Ab-positive blood, saliva, and urine were analyzed for the presence of viral RNA by nested RT-PCR. From 727 non-oryzomyine captures, five seropositive (but not viral RNA positive) individuals were detected: one each of Baiomys taylori, Peromyscus leucopus, and Reithrodontomys fulvescens; and two Sigmodon hispidus. Spillover hosts were not associated with macrohabitat where O. palustris abundance, density, or seroprevalence was highest. Rather, spillover occurred in the macrohabitat indicative of greater overall disturbance (as indicated by grazing and exotic plant diversity) and overall biodiversity. Spillover occurred during periods of high seroprevalence detected elsewhere within the study region. Spillover locations differed significantly from all other capture locations in terms of percent water, shrub, and grass cover. Although greater habitat and mammal diversity of old-fields may serve to reduce seroprevalence levels by tempering intraspecific contacts between rice rats, greater diversity also may create an ecologically opportunistic setting for BAYV spillover. Impacts of varying levels of disturbance and biodiversity on transmission dynamics represent a vastly uncharacterized component of the evolutionary ecology of hantaviruses. PMID:20836801

  7. A bioaccumulation bioassay for freshwater sediments

    USGS Publications Warehouse

    Mac, Michael J.; Noguchi, George E.; Hesselberg, Robert J.; Edsall, Carol C.; Shoesmith, John A.; Bowker, James D.

    1990-01-01

    A laboratory bioassay is described for determining the bioavailability of contaminants from freshwater sediments. The bioassay consists of 10-d exposures to whole sediments under flow-through conditions. After testing five species, the fathead minnow (Pimephales promelas) and the earthworm (Lubricus terrestris) were recommended for use in the test. When the availability of polychlorinated biphenyls (PCBs), Hg and Zn from Great Lakes sediments was examined in laboratory exposures, only the PCBs were accumulated. A field validation study demonstrated that the magnitude of accumulation in laboratory exposures was similar to that in organisms caged in the field. A protocol is recommended for using the test as a standardized bioaccumulation bioassay.

  8. Freshwater aspects of anadromous salmonid enhancement

    USGS Publications Warehouse

    Gould, Rowan W.

    1982-01-01

    Freshwater enhancement of anadromous salmonid populations has been practiced in the United States and Canada since the late 1800's. Reduction of natural spawning habitat and increasing fishing pressure make artificial enhancement a possible alternative to declining populations. Enhancement of anadromous salmonids involved improvement of the natural environment and reducing natural mortality. Methods of enhancement include fishways, spawning and rearing channels, stream rehabilitation, lake fertilization, environmental management, and artificial propagation techniques. Five Pacific salmon species and steelhead trout are commonly enhanced, primarily in watershed entering the Pacific Ocean and Great Lakes. Enhancement efforts contribute heavily to a commercial and sport industry realizing over $1.5 billion.

  9. Freshwater fluxes through the Western Fram Strait

    NASA Astrophysics Data System (ADS)

    Meredith, Michael; Heywood, Karen; Dennis, Paul; Goldson, Laura; White, Rowan; Fahrbach, Eberhard; Schauer, Ursula; Østerhus, Svein

    Two hydrographic and δ18O transects across Fram Strait (Aug-Sept 1997, 1998) are used to examine freshwater contributions to the East Greenland Current (EGC). The EGC featured up to ˜16% meteoric water in both years, but was made comparatively more saline through the formation of up to ˜11 m of sea ice. We derive meteoric water fluxes of ˜3680 km³yr-1 in Aug-Sept 1997, and ˜2000 km³yr-1 in Aug-Sept 1998. The 1997 and 1998 data show a long-term mean sea ice flux through Fram Strait around half the long-term mean meteoric water flux. A 1991 δ18O section [Bauch et al., 1995] yielded a very similar ratio. Our 1998 section reveals fresh, low-δ18O water on the East Greenland shelf whose comparatively large volume constitutes a potentially significant contribution to the total freshwater flux through Fram Strait. Such fluxes are important to the regional and global thermohaline circulation; we suggest that efforts towards monitoring both the EGC and East Greenland shelf waters are thus required.

  10. Climate and local abundance in freshwater fishes

    PubMed Central

    Knouft, Jason H.; Anthony, Melissa M.

    2016-01-01

    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide variation in population abundance associated with environmental conditions has been investigated in terrestrial species, the relationship between climate and local abundance in freshwater taxa across species' distributions is not well understood. We used GIS-based temperature and precipitation data to determine the relationships between climatic conditions and range-wide variation in local abundance for 19 species of North American freshwater fishes. Climate predicted a portion of the variation in local abundance among populations for 18 species. In addition, the relationship between climatic conditions and local abundance varied among species, which is expected as lineages partition the environment across geographical space. The influence of local habitat quality on species persistence is well documented; however, our results also indicate the importance of climate in regulating population sizes across a species geographical range, even in aquatic taxa. PMID:27429769

  11. Heart Rate Sensor for Freshwater Mussels

    NASA Astrophysics Data System (ADS)

    Just, C. L.; Vial, D. P.; Kruger, A.; Niemeier, J. J.; Lee, H. W.; Schroer, H. W.

    2014-12-01

    Researchers have long been interested the cardiac activity of mollusks. First, it is important as a basic measure of the animal's metabolism. Further, activities such as feeding and burrowing affect heart rate, as do environmental factors such as water salinity, water temperature, exposure, and predation. We have developed a small, noninvasive sensor for measuring freshwater mussel heart rate. Its working principle is as follows. An infrared (IR) light-emitting diode is placed in contact with the mussel shell. Some of the IR penetrates through the shell, reflects off internal organs, and traverses back. A photodetector detects this IR, and electronics condition the signal. The heartbeat of the animal modulates the IR, allowing one to measure the heart rate. The technique is widely-used in finger heart-rate monitors in humans. The sensors do not have to be positioned above the heart and several locations on the mussel shell work well. The sensor is small (8 mm × 10 mm) and consumes less than 1 mA, and has a simple one-wire interface that allows for easy integration into data acquisition hardware. We present heart rate measurements for the common pocketbook (lampsilis cardium) freshwater mussel.

  12. Reclaiming freshwater sustainability in the Cadillac Desert

    PubMed Central

    Sabo, John L.; Sinha, Tushar; Bowling, Laura C.; Schoups, Gerrit H. W.; Wallender, Wesley W.; Campana, Michael E.; Cherkauer, Keith A.; Fuller, Pam L.; Graf, William L.; Hopmans, Jan W.; Kominoski, John S.; Taylor, Carissa; Trimble, Stanley W.; Webb, Robert H.; Wohl, Ellen E.

    2010-01-01

    Increasing human appropriation of freshwater resources presents a tangible limit to the sustainability of cities, agriculture, and ecosystems in the western United States. Marc Reisner tackles this theme in his 1986 classic Cadillac Desert: The American West and Its Disappearing Water. Reisner's analysis paints a portrait of region-wide hydrologic dysfunction in the western United States, suggesting that the storage capacity of reservoirs will be impaired by sediment infilling, croplands will be rendered infertile by salt, and water scarcity will pit growing desert cities against agribusiness in the face of dwindling water resources. Here we evaluate these claims using the best available data and scientific tools. Our analysis provides strong scientific support for many of Reisner's claims, except the notion that reservoir storage is imminently threatened by sediment. More broadly, we estimate that the equivalent of nearly 76% of streamflow in the Cadillac Desert region is currently appropriated by humans, and this figure could rise to nearly 86% under a doubling of the region's population. Thus, Reisner's incisive journalism led him to the same conclusions as those rendered by copious data, modern scientific tools, and the application of a more genuine scientific method. We close with a prospectus for reclaiming freshwater sustainability in the Cadillac Desert, including a suite of recommendations for reducing region-wide human appropriation of streamflow to a target level of 60%. PMID:21149727

  13. Ecogeomorphological feedbacks in a tidal freshwater marsh

    NASA Astrophysics Data System (ADS)

    Palinkas, C. M.; Engelhardt, K.

    2013-12-01

    Tidal freshwater marshes are critical components of fluvial and estuarine ecosystems. However, ecogeomorphological feedbacks (i.e., feedbacks between sediment dynamics and the vegetation community) in freshwater marshes have not received as much attention as within their saltwater counterparts. This study evaluates the role of these feedbacks in stabilizing marsh-surface elevation, relative to sea-level rise, in Dyke Marsh Preserve (Potomac River, USA). Specifically, we relate the composition of the vegetation community to current and historical patterns of sedimentation that occur on bimonthly to decadal time scales. Along with a ~3-year time series of bimonthly and seasonal-scale observations, 210Pb (half-life 22.3 y) profiles are used to identify sites with relatively steady sediment accumulation (i.e., stable sediments) and those with numerous deposition/erosion events (i.e., unstable sediments). Differences in the vegetation community (e.g., composition, stem density) and sediment character (e.g., organic content, grain size) among sites in each of these stability categories are examined with statistical techniques and compared to observations of marsh-surface elevation change. The resulting insights are placed into a geomorphological context to assess the potential response of this marsh to rapid global environmental change.

  14. Reclaiming freshwater sustainability in the Cadillac Desert

    USGS Publications Warehouse

    Sabo, John L.; Sinha, Tushar; Bowling, Laura C.; Schoups, Gerrit H.W.; Wallender, Wesley W.; Campana, Michael E.; Cherkauer, Keith A.; Fuller, Pam L.; Graf, William L.; Hopmans, Jan W.; Kominoski, John S.; Taylor, Carissa; Trimble, Stanley W.; Webb, Robert H.; Wohl, Ellen E.

    2010-01-01

    Increasing human appropriation of freshwater resources presents a tangible limit to the sustainability of cities, agriculture, and ecosystems in the western United States. Marc Reisner tackles this theme in his 1986 classic Cadillac Desert: The American West and Its Disappearing Water. Reisner's analysis paints a portrait of region-wide hydrologic dysfunction in the western United States, suggesting that the storage capacity of reservoirs will be impaired by sediment infilling, croplands will be rendered infertile by salt, and water scarcity will pit growing desert cities against agribusiness in the face of dwindling water resources. Here we evaluate these claims using the best available data and scientific tools. Our analysis provides strong scientific support for many of Reisner's claims, except the notion that reservoir storage is imminently threatened by sediment. More broadly, we estimate that the equivalent of nearly 76% of streamflow in the Cadillac Desert region is currently appropriated by humans, and this figure could rise to nearly 86% under a doubling of the region's population. Thus, Reisner's incisive journalism led him to the same conclusions as those rendered by copious data, modern scientific tools, and the application of a more genuine scientific method. We close with a prospectus for reclaiming freshwater sustainability in the Cadillac Desert, including a suite of recommendations for reducing region-wide human appropriation of streamflow to a target level of 60%.

  15. Climate and local abundance in freshwater fishes.

    PubMed

    Knouft, Jason H; Anthony, Melissa M

    2016-06-01

    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide variation in population abundance associated with environmental conditions has been investigated in terrestrial species, the relationship between climate and local abundance in freshwater taxa across species' distributions is not well understood. We used GIS-based temperature and precipitation data to determine the relationships between climatic conditions and range-wide variation in local abundance for 19 species of North American freshwater fishes. Climate predicted a portion of the variation in local abundance among populations for 18 species. In addition, the relationship between climatic conditions and local abundance varied among species, which is expected as lineages partition the environment across geographical space. The influence of local habitat quality on species persistence is well documented; however, our results also indicate the importance of climate in regulating population sizes across a species geographical range, even in aquatic taxa. PMID:27429769

  16. Microbial degradation of microcystin in Florida's freshwaters.

    PubMed

    Ramani, A; Rein, K; Shetty, K G; Jayachandran, K

    2012-02-01

    Presence of microcystin (MC), a predominant freshwater algal toxin and a suspected liver carcinogen, in Florida's freshwaters poses serious health threat to humans and aquatic species. Being recalcitrant to conventional physical and chemical water treatment methods, biological methods of MC removal is widely researched. Water samples collected from five sites of Lake Okeechobee (LO) frequently exposed to toxic Microcystis blooms were used as inoculum for enrichment with microcystin LR (MC-LR) supplied as sole C and N source. After 20 days incubation, MC levels were analyzed using high performance liquid chromatography (HPLC). A bacterial consortium consisting of two isolates DC7 and DC8 from the Indian Prairie Canal sample showed over 74% toxin degradation at the end of day 20. Optimal temperature requirement for biodegradation was identified and phosphorus levels did not affect the MC biodegradation. Based on 16S rRNA sequence similarity the isolate DC8 was found to have a match with Microbacterium sp. and the DC7 isolate with Rhizobium gallicum (AY972457). PMID:21611743

  17. Institutional development of freshwater fish stocking in Mexico.

    PubMed

    Ibáñez, A L; Pérez-Ramírez, M; García-Calderón, J L

    2014-12-01

    By using freshwater fish stocking information from the Mexican government, this work described the current situation of the national stocking and its associated fishery policy. There is a lack of effective freshwater stocking programmes as a result of limited fisheries management, unharmonized fisheries regulations and institutional performance. The fry production has decreased from 140 to 20 million in the past 11 years. PMID:25146570

  18. A subtropical fate awaited freshwater discharged from glacial Lake Agassiz

    SciTech Connect

    Condron, Alan; Winsor, Peter

    2011-02-10

    The 8.2 kyr event is the largest abrupt climatic change recorded in the last 10,000 years, and is widely hypothesized to have been triggered by the release of thousands of kilometers cubed of freshwater into the North Atlantic Ocean. Using a high-resolution (1/6°) global, ocean-ice circulation model we present an alternative view that freshwater discharged from glacial Lake Agassiz would have remained on the continental shelf as a narrow, buoyant, coastal current, and would have been transported south into the subtropical North Atlantic. The pathway we describe is in contrast to the conceptual idea that freshwater from this lake outburst spread over most of the sub-polar North Atlantic, and covered the deep, open-ocean, convection regions. This coastally confined freshwater pathway is consistent with the present-day routing of freshwater from Hudson Bay, as well as paleoceanographic evidence of this event. In this study, using a coarse-resolution (2.6°) version of the same model, we demonstrate that the previously reported spreading of freshwater across the sub-polar North Atlantic results from the inability of numerical models of this resolution to accurately resolve narrow coastal flows, producing instead a diffuse circulation that advects freshwater away from the boundaries. To understand the climatic impact of freshwater released in the past or future (e.g. Greenland and Antarctica), the ocean needs to be modeled at a resolution sufficient to resolve the dynamics of narrow, coastal buoyant flows.

  19. FRESHWATER POTOMAC LONG-TERM BENTHIC MONITORING PROGRAM

    EPA Science Inventory

    The Maryland Department of the Environments Freshwater Potomac Long-Term Benthic Monitoring Program provides seasonal information on abundance and composition for the benthic fauna of the freshwater portion of the Potomac River for use in recommendations to State agencies accordi...

  20. THREATENED AND ENDANGERED FRESHWATER FISH AND MUSSEL SPECIES RICHNESS

    EPA Science Inventory

    These data represent predicted current distributions of all US listed Threatened and Endangered freshwater fish and freshwater mussels in the Middle-Atlantic region. The data are available for both 8-digit HUCs and EMAP hexagons and represent total species counts for each spatia...

  1. Recent changes in the freshwater composition east of Greenland

    NASA Astrophysics Data System (ADS)

    Steur, L.; Pickart, R. S.; Torres, D. J.; Valdimarsson, H.

    2015-04-01

    Results from three hydrographic surveys across the East Greenland Current between 2011 and 2013 are presented with focus on the freshwater sources. End-member analysis using salinity, δ18O, and nutrient data shows that while meteoric water dominated the freshwater content, a significant amount of Pacific freshwater was present near Denmark Strait with a maximum in August 2013. While in 2011 and 2012 the net sea ice melt was dominated by brine, in 2013 it became close to zero. The amount of Pacific freshwater observed near Denmark Strait in 2013 is as large as the previous maximum in 1998. This, together with the decrease in meteoric water and brine, suggests a larger contribution from the Canadian Basin. We hypothesize that the increase of Pacific freshwater is the result of enhanced flux through Bering Strait and a shorter pathway of Pacific water through the interior Arctic to Fram Strait.

  2. Pesticide toxicity index for freshwater aquatic organisms

    USGS Publications Warehouse

    Munn, Mark D.; Gilliom, Robert J.

    2001-01-01

    The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is designed to assess current water-quality conditions, changes in water quality over time, and the effects of natural and human factors on water quality for the Nation's streams and ground-water resources. For streams, one of the most difficult parts of the assessment is to link chemical conditions to effects on aquatic biota, particularly for pesticides, which tend to occur in streams as complex mixtures with strong seasonal patterns. A Pesticide Toxicity Index (PTI) was developed that combines pesticide exposure of aquatic biota (measured concentrations of pesticides in stream water) with toxicity estimates (standard endpoints from laboratory bioassays) to produce a single index value for a sample or site. The development of the PTI was limited to pesticide compounds routinely measured in NAWQA studies and to toxicity data readily available from existing databases. Qualifying toxicity data were found for one or more types of test organisms for 75 of the 83 pesticide compounds measured in NAWQA samples, but with a wide range of bioassays per compound (1 to 65). There were a total of 2,824 bioassays for the 75 compounds, including 287 48-hour EC50 values (concentration at which 50 percent of test organisms exhibit a nonlethal response) for freshwater cladocerans, 585 96-hour LC50 values (concentration lethal to 50 percent of test organisms) for freshwater benthic invertebrates, and 1,952 96-hour LC50 values for freshwater fish. The PTI for a particular sample is the sum of toxicity quotients (measured concentration divided by the median toxicity concentration from bioassays) for each detected pesticide. The PTI can be calculated for specific groups of pesticides and for specific taxonomic groups.While the PTI does not determine whether water in a sample is toxic, its values can be used to rank or compare the toxicity of samples or sites on a relative basis for use in further analysis or

  3. Gastric cryptosporidiosis in freshwater angelfish (Pterophyllum scalare).

    PubMed

    Murphy, Brian G; Bradway, Daniel; Walsh, Timothy; Sanders, George E; Snekvik, Kevin

    2009-09-01

    A freshwater angelfish (Pterophyllum scalare) hatchery experienced variable levels of emaciation, poor growth rates, swollen coelomic cavities, anorexia, listlessness, and increased mortality within their fish. Multiple chemotherapeutic trials had been attempted without success. In affected fish, large numbers of protozoa were identified both histologically and ultrastructurally associated with the gastric mucosa. The youngest cohort of parasitized fish was the most severely affected and demonstrated the greatest morbidity and mortality. The protozoa were morphologically most consistent with Cryptosporidium. All of the protozoan life stages were identified ultrastructurally and protozoal genomic DNA was isolated from parasitized tissue viscera and sequenced. Histological, ultrastructural, genetic, and phylogenetic analyses confirmed this protozoal organism to be a novel species of Cryptosporidium. PMID:19737774

  4. Freshwater snail consumption and angiostrongyliasis in Malaya.

    PubMed

    Liat, L B; Fong, Y L; Krishnansamy, M; Ramachandran, P; Mansor, S

    1978-06-01

    A survey of the freshwater snails, Pila scutata and Bellamyia ingallsiana, as food consumed by the local population was carried out in Peninsular Malaysia. Of these two species the first is preferred; the sizes favoured are between 25--40 mm. Pila snails were found to be consumed by the three communities, viz. Malay, Chinese and Indian, in different ways. The various methods of preparing the snails for consumption are described. P. scutata is an intermediate host of the rat-lung worm, Angiostrongylus malaysiensis. As this worm presumably is the causative agent of human eosinophilic meningoencephalitis, the eating habits of the three races in consuming the snail in relation to the epidemiology of the disease was also discussed. PMID:726037

  5. Ancient androdioecy in the freshwater crustacean Eulimnadia

    PubMed Central

    Weeks, Stephen C; Sanderson, Thomas F; Reed, Sadie K; Zofkova, Magdalena; Knott, Brenton; Balaraman, Usha; Pereira, Guido; Senyo, Diana M; Hoeh, Walter R

    2005-01-01

    Among the variety of reproductive mechanisms exhibited by living systems, one permutation—androdioecy (mixtures of males and hermaphrodites)—is distinguished by its rarity. Models of mating system evolution predict that androdioecy should be a brief stage between hermaphroditism and dioecy (separate males and females), or vice versa. Herein we report evidence of widespread and ancient androdioecy in crustaceans in the genus Eulimnadia, based on observations of over 33 000 shrimp from 36 locations from every continent except Antarctica. Using phylogenetic, biogeographical and palaeontological evidence, we infer that androdioecy in Eulimnadia has persisted for 24–180 million years and has been maintained through multiple speciation events. These results suggest that androdioecy is a highly successful aspect of the life history of these freshwater crustaceans, and has persisted for orders of magnitude longer than predicted by current models of this rare breeding system. PMID:16608693

  6. Gastric cryptosporidiosis in freshwater angelfish (Pterophyllum scalare)

    USGS Publications Warehouse

    Murphy, B.G.; Bradway, D.; Walsh, T.; Sanders, G.E.; Snekvik, K.

    2009-01-01

    A freshwater angelfish (Pterophyllum scalare) hatchery experienced variable levels of emaciation, poor growth rates, swollen coelomic cavities, anorexia, listlessness, and increased mortality within their fish. Multiple chemotherapeutic trials had been attempted without success. In affected fish, large numbers of protozoa were identified both histologically and ultrastructurally associated with the gastric mucosa. The youngest cohort of parasitized fish was the most severely affected and demonstrated the greatest morbidity and mortality. The protozoa were morphologically most consistent with Cryptosporidium. All of the protozoan life stages were identified ultrastructurally and protozoal genomic DNA was isolated from parasitized tissue viscera and sequenced. Histological, ultrastructural, genetic, and phylogenetic analyses confirmed this protozoal organism to be a novel species of Cryptosporidium.

  7. The decline of North American freshwater fishes

    USGS Publications Warehouse

    Walsh, Stephen J.; Jelks, Howard L.; Burkhead, Noel M.

    2009-01-01

    North America has a broad array of freshwater ecosystems because of the continent's complex geography and geological history. Within a multitude of habitats—that include streams, large rivers, natural lakes, springs, and wetlands—rich assemblages of fishes reside, representing diverse taxonomic groups with unique ecological requirements. They face an unprecedented conservation crisis.1 In the last few decades, the proportion of inland fishes of North America, which are considered imperiled or extinct, increased from 20 to 40%.2 Although extinctions have occurred, many species and populations are declining in range size and abundance. The fish biota of the continent as a whole remains diverse; however, we can take action to stem any further declines.

  8. Toxicities of selected substances to freshwater biota

    SciTech Connect

    Hohreiter, D.W.

    1980-05-01

    The amount of data available concerning the toxicity of various substances to freshwater biota is so large that it is difficult to use in a practical situation, such as environmental impact assessment. In this document, summary tables are presented showing acute and/or chronic toxicity of selected substances for various groups of aquatic biota. Each entry is referenced to its original source so that details concerning experimental conditions may be consulted. In addition, general information concerning factors modifying toxicity, synergisms, evidence of bioaccumulation, and water quality standards and criteria for the selected substances is given. The final table is a general toxicity table designed to provide an easily accessible and general indication of toxicity of selected substances in aquatic systems.

  9. Global climate change and freshwater ecosystems

    SciTech Connect

    Firth, P.; Fisher, S.G.

    1992-01-01

    This book is based on a symposium held in May 1990, sponsored by NASA, US EPA, and the North American Benthological Society. It focuses on the potential interactions between climate change and freshwater ecosystems. The assumption of global warming 2-5 degrees occurring in the next century was presented to the authors by the editors, and each author was asked to comment on how this warming might affect their particular system or process of interest. The book deals primarily with streams in the USA. Other chapters deal with the following topics: mechanisms driving global climate change; remote sensing; wetlands; lakes; general issues related to water resources and regional studies as they apply to flowing water.

  10. Eutrophication of freshwater and marine ecosystems

    USGS Publications Warehouse

    Smith, Val H.; Joye, Samantha B.; Howarth, Robert W.

    2006-01-01

    Initial understanding of the links between nutrients and aquatic productivity originated in Europe in the early 1900s, and our knowledge base has expanded greatly during the past 40 yr. This explosion of eutrophication-related research has made it unequivocally clear that a comprehensive strategy to prevent excessive amounts of nitrogen and phosphorus from entering our waterways is needed to protect our lakes, rivers, and coasts from water quality deterioration. However, despite these very significant advances, cultural eutrophication remains one of the foremost problems for protecting our valuable surface water resources. The papers in this special issue provide a valuable cross section and synthesis of our current understanding of both freshwater and marine eutrophication science. They also serve to identify gaps in our knowledge and will help to guide future research.

  11. Carcinogens and cancers in freshwater fishes.

    PubMed Central

    Black, J J; Baumann, P C

    1991-01-01

    Epizootics of neoplasms in freshwater fish species are considered in relation to circumstantial and experimental evidence that suggest that some epizootics of neoplasia of hepatocellular, cholangiocellular, epidermal, and oral epithelial origin may be causally related to contaminant exposure. Although there is concern for the safety of consuming fish affected with neoplasms, this concern may be misdirected as direct transmission of cancer by ingesting cancerous tissue would seem unlikely. Of greater concern is the matter of toxic and cancer-causing chemicals present in edible fish that exhibit neoplasia as a symptom of past exposure via residence in a polluted waterway. There is ample evidence to suggest that contaminant chemicals ingested via contaminated Great Lakes fish may already be affecting both human and ecosystem health, but these effects are subtle and may require new approaches to the study of the affected systems. PMID:2050071

  12. Estimated Freshwater Withdrawals in Oklahoma, 1990

    USGS Publications Warehouse

    Lurry, Dee L.; Tortorelli, Robert L.

    1996-01-01

    This report presents 1990 freshwater withdrawal estimates for Oklahoma by source and category. Withdrawal source is either ground water or surface water. Withdrawal categories include: irrigation, water supply, livestock, thermoelectric-power generation, domestic and commercial, and industrial and mining. Withdrawal data are aggregated by county, major aquifer, and principal river basin. Only the four major categories of irrigation, water supply, livestock, and thermoelectric-power generation are illustrated in this report, although data for all categories are tabulated. The U.S. Geological Survey (USGS) established the National Water-Use Information Program in 1977 to collect uniform, current, and reliable information on water use. The Oklahoma District of the USGS and the Oklahoma Water Resources Board participate in a cooperative program to collect and publish water-use information for Oklahoma. Data contained in this report were made available through the cooperative program.

  13. Arctic Ocean basin liquid freshwater storage trend 1992-2012

    NASA Astrophysics Data System (ADS)

    Rabe, B.; Karcher, M.; Kauker, F.; Schauer, U.; Toole, J. M.; Krishfield, R. A.; Pisarev, S.; Kikuchi, T.; Su, J.

    2014-02-01

    Freshwater in the Arctic Ocean plays an important role in the regional ocean circulation, sea ice, and global climate. From salinity observed by a variety of platforms, we are able, for the first time, to estimate a statistically reliable liquid freshwater trend from monthly gridded fields over all upper Arctic Ocean basins. From 1992 to 2012 this trend was 600±300 km3 yr-1. A numerical model agrees very well with the observed freshwater changes. A decrease in salinity made up about two thirds of the freshwater trend and a thickening of the upper layer up to one third. The Arctic Ocean Oscillation index, a measure for the regional wind stress curl, correlated well with our freshwater time series. No clear relation to Arctic Oscillation or Arctic Dipole indices could be found. Following other observational studies, an increased Bering Strait freshwater import to the Arctic Ocean, a decreased Davis Strait export, and enhanced net sea ice melt could have played an important role in the freshwater trend we observed.

  14. Global patterns of freshwater species diversity, threat and endemism

    PubMed Central

    Collen, Ben; Whitton, Felix; Dyer, Ellie E; Baillie, Jonathan E M; Cumberlidge, Neil; Darwall, William R T; Pollock, Caroline; Richman, Nadia I; Soulsby, Anne-Marie; Böhm, Monika

    2014-01-01

    Aim Global-scale studies are required to identify broad-scale patterns in the distributions of species, to evaluate the processes that determine diversity and to determine how similar or different these patterns and processes are among different groups of freshwater species. Broad-scale patterns of spatial variation in species distribution are central to many fundamental questions in macroecology and conservation biology. We aimed to evaluate how congruent three commonly used metrics of diversity were among taxa for six groups of freshwater species. Location Global. Methods We compiled geographical range data on 7083 freshwater species of mammals, amphibians, reptiles, fishes, crabs and crayfish to evaluate how species richness, richness of threatened species and endemism are distributed across freshwater ecosystems. We evaluated how congruent these measures of diversity were among taxa at a global level for a grid cell size of just under 1°. Results We showed that although the risk of extinction faced by freshwater decapods is quite similar to that of freshwater vertebrates, there is a distinct lack of spatial congruence in geographical range between different taxonomic groups at this spatial scale, and a lack of congruence among three commonly used metrics of biodiversity. The risk of extinction for freshwater species was consistently higher than for their terrestrial counterparts. Main conclusions We demonstrate that broad-scale patterns of species richness, threatened-species richness and endemism lack congruence among the six freshwater taxonomic groups examined. Invertebrate species are seldom taken into account in conservation planning. Our study suggests that both the metric of biodiversity and the identity of the taxa on which conservation decisions are based require careful consideration. As geographical range information becomes available for further sets of species, further testing will be warranted into the extent to which geographical variation in

  15. Sex identification and PIT-tagging: tools and prospects for studying intersexual differences in freshwater fishes.

    PubMed

    Hulthén, K; Chapman, B B; Nilsson, P A; Hansson, L-A; Skov, C; Baktoft, H; Brodersen, J; Brönmark, C

    2014-02-01

    This study evaluated a technique to allow the long-term monitoring of individual fishes of known sex in the wild using sex confirmation in close proximity to the reproductive period combined with individual tagging. Hundreds of partially migratory roach Rutilus rutilus were tagged with passive integrated transponders (PIT) following sex determination in spring and various performance measures were compared with fish tagged outside the reproductive period in autumn. Short-term survival was >95% for R. rutilus sexed and tagged under natural field conditions. Total length (LT ) did not affect the probability of survival within the size range tagged (119-280 mm), nor were there differences in timing of migration the following season between individuals sexed and tagged in spring and individuals tagged in autumn (i.e. outside the reproductive period). Also, a similar per cent of R. rutilus sexed and tagged in spring and tagged in autumn migrated the following season (34·5 and 34·7%). Moreover, long-term recapture data revealed no significant differences in body condition between R. rutilus individuals sexed and tagged in spring, individuals tagged in autumn and unmanipulated individuals. The observed sex ratio of recaptured fish did not differ from the expected values of equal recapture rates between males and females. Hence, there is no observable evidence for an adverse effect of tagging close to the reproductive period and therefore this method is suitable for studying intersexual differences and other phenotypic traits temporarily expressed during reproduction at the individual level in fishes. PMID:24490936

  16. AN INTEGRATED WATERSHED APPROACH LINKING SALMONID PRODUCTIVITY TO FRESHWATER HABITAT

    EPA Science Inventory

    EPA's Western Ecology Division is undertaking research addressing catchment-scale dynamics of freshwater habitat productivity for native fishes. Through partnerships with state and federal agencies and private landowners, current field efforts focus on linkages among stream chemi...

  17. Methods for freshwater riverine input into regional ocean models

    NASA Astrophysics Data System (ADS)

    Herzfeld, M.

    2015-06-01

    The input of freshwater at the coast in regional models is a non-trivial exercise that has been studied extensively in the past. Several issues are of relevance; firstly, estuaries process water properties along their length, so that while freshwater may enter at the estuary head, it is no longer fresh at the mouth. Secondly, models create a numerical response that results in excessive upstream or offshore transport compared to what is typically observed. The cause of this has been traced to the lack of landward flow at the coast where freshwater is input. In this study we assess the performance of various methods of freshwater input in coarse resolution regional models where the estuary cannot be explicitly resolved, and present a formulation that attempts to account for upstream flow in the salt wedge and in-estuary mixing that elevates salinity at the mouth.

  18. SUSPENDED AND DISSOLVED SOLIDS EFFECTS ON FRESHWATER BIOTA: A REVIEW

    EPA Science Inventory

    It is widely recognized that suspended and dissolved solids in lakes, rivers, streams, and reservoirs affect water quality. In this report the research needs appropriate to setting freshwater quality criteria or standards for suspended solids (not including bedload) and dissolved...

  19. Extinction rates in North American freshwater fishes, 1900-2010

    USGS Publications Warehouse

    Burkhead, Noel M.

    2012-01-01

    Widespread evidence shows that the modern rates of extinction in many plants and animals exceed background rates in the fossil record. In the present article, I investigate this issue with regard to North American freshwater fishes. From 1898 to 2006, 57 taxa became extinct, and three distinct populations were extirpated from the continent. Since 1989, the numbers of extinct North American fishes have increased by 25%. From the end of the nineteenth century to the present, modern extinctions varied by decade but significantly increased after 1950 (post-1950s mean = 7.5 extinct taxa per decade). In the twentieth century, freshwater fishes had the highest extinction rate worldwide among vertebrates. The modern extinction rate for North American freshwater fishes is conservatively estimated to be 877 times greater than the background extinction rate for freshwater fishes (one extinction every 3 million years). Reasonable estimates project that future increases in extinctions will range from 53 to 86 species by 2050.

  20. ALGAL METABOLITE INFLUENCE ON BLOOM SEQUENCE IN EUTROPHIED FRESHWATER PONDS

    EPA Science Inventory

    The extracellular metabolites of planktonic bloom dominant algae play a most significant role in the determination of bloom sequence in a eutrophied freshwater pond. Certain extracellular metabolites of planktonic blue-green algae substantially inhibit the growth of planktonic di...

  1. A new numerical benchmark of a freshwater lens

    NASA Astrophysics Data System (ADS)

    Stoeckl, L.; Walther, M.; Graf, T.

    2016-04-01

    A numerical benchmark for 2-D variable-density flow and solute transport in a freshwater lens is presented. The benchmark is based on results of laboratory experiments conducted by Stoeckl and Houben (2012) using a sand tank on the meter scale. This benchmark describes the formation and degradation of a freshwater lens over time as it can be found under real-world islands. An error analysis gave the appropriate spatial and temporal discretization of 1 mm and 8.64 s, respectively. The calibrated parameter set was obtained using the parameter estimation tool PEST. Comparing density-coupled and density-uncoupled results showed that the freshwater-saltwater interface position is strongly dependent on density differences. A benchmark that adequately represents saltwater intrusion and that includes realistic features of coastal aquifers or freshwater lenses was lacking. This new benchmark was thus developed and is demonstrated to be suitable to test variable-density groundwater models applied to saltwater intrusion investigations.

  2. ENVIRONMENTAL REQUIREMENTS AND POLLUTION TOLERANCE OF COMMON FRESHWATER CHIRONOMIDAE

    EPA Science Inventory

    Data on the environmental requirements and pollution tolerance of 230 taxa of freshwater chironomids were compiled from 33 references. This compilation was prepared to assist biologists in evaluating data from macroinvertebrate samples collected for the assessment of water qualit...

  3. [Latin American malacology. Freshwater mollusks from Argentina].

    PubMed

    Rumi, Alejandra; Gregoric, Diego E Gutiérrez; Núñez, Verónica; Darrigran, Gustavo A

    2008-03-01

    A report and an updated list with comments on the species of freshwater molluscs of Argentina which covers an area of 2 777 815 km2 is presented. Distributions of Gastropoda and Bivalvia families, endemic, exotic, invasive as well as entities of sanitary importance are also studied and recommendations on their conservation are provided. Molluscs related to the Del Plata Basin have been thoroughly studied in comparison to others areas of the country. This fauna exhibits relatively the biggest specific richness and keeps its affinity with the fauna of other regions of the basin in areas of Paraguay and Brasil. The 4 500 records of molluscs considered in this paper arise from the study of the collections of Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Buenos Aires; Museo de La Plata, La Plata and Fundación "Miguel Lillo", Tucumán. These institutions keep very important collections of molluscs in southern South America. Field information has recently been obtained and localities cited by other authors are also included in the data base. Until today, 166 species have been described, 101 belonging to 10 families of Gastropoda and 65 to 7 of Bivalvia. Families with highest specific richness are Lithoglyphidae (22) and Sphaeriidae (25), respectively. The number of endemic species (those present only in Argentina) by family is: Gastropoda: Ampullariidae (1), Cochliopidae (10), Lithoglyphidae (11), Thiariidae (3), Chilinidae (11), Lymnaeidae (2) and Physidae (2?); Bivalvia: Hyriidae (1?); Etheriidae (1?) and Sphaeriidae (10). Families with a distribution that comprise almost the whole country are: the Sphaeriidae and the gastropods Cochliopidae, Chilinidae and Lymnaeidae. Families Erodonidae and Solecurtidae (Bivalvia) were registered in mixohaline environments from Buenos Aires province. Gastropod families Thiaridae and Glacidorbiidae show a very restricted distribution. The rest of the families are present mainly in the center and north of the country

  4. A subtropical fate awaited freshwater discharged from glacial Lake Agassiz

    DOE PAGESBeta

    Condron, Alan; Winsor, Peter

    2011-02-10

    The 8.2 kyr event is the largest abrupt climatic change recorded in the last 10,000 years, and is widely hypothesized to have been triggered by the release of thousands of kilometers cubed of freshwater into the North Atlantic Ocean. Using a high-resolution (1/6°) global, ocean-ice circulation model we present an alternative view that freshwater discharged from glacial Lake Agassiz would have remained on the continental shelf as a narrow, buoyant, coastal current, and would have been transported south into the subtropical North Atlantic. The pathway we describe is in contrast to the conceptual idea that freshwater from this lake outburstmore » spread over most of the sub-polar North Atlantic, and covered the deep, open-ocean, convection regions. This coastally confined freshwater pathway is consistent with the present-day routing of freshwater from Hudson Bay, as well as paleoceanographic evidence of this event. In this study, using a coarse-resolution (2.6°) version of the same model, we demonstrate that the previously reported spreading of freshwater across the sub-polar North Atlantic results from the inability of numerical models of this resolution to accurately resolve narrow coastal flows, producing instead a diffuse circulation that advects freshwater away from the boundaries. To understand the climatic impact of freshwater released in the past or future (e.g. Greenland and Antarctica), the ocean needs to be modeled at a resolution sufficient to resolve the dynamics of narrow, coastal buoyant flows.« less

  5. Sensitivity of hypogean and epigean freshwater copepods to agricultural pollutants.

    PubMed

    Di Lorenzo, T; Di Marzio, W D; Sáenz, M E; Baratti, M; Dedonno, A A; Iannucci, A; Cannicci, S; Messana, G; Galassi, D M P

    2014-03-01

    Widespread pollution from agriculture is one of the major causes of the poor freshwater quality currently observed across Europe. Several studies have addressed the direct impact of agricultural pollutants on freshwater biota by means of laboratory bioassays; however, as far as copepod crustaceans are concerned, the ecotoxicological research is scarce for freshwater species and almost nonexistent for the hypogean ones. In this study, we conducted a comparative analysis of the available literature data on the sensitivity of freshwater copepods to agricultural pollutants. We also assessed the acute and chronic sensitivity of a hypogean and an epigean species, both belonging to the Crustacea Copepoda Cyclopoida Cyclopidae, to two N-fertilizers (urea and ammonium nitrate) and two herbicides (ARIANE(TM) II from Dow AgroSciences LLC, and Imazamox), widely used for cereal agriculture in Europe. According to the literature review, freshwater copepods are sensitive to a range of pesticides and N-fertilizers. Ecotoxicological studies on hypogean species of copepods account only one study. There are no standardized protocols available for acute and chronic toxicity tests for freshwater copepods, making comparisons about sensitivity difficult. From our experiments, ionized ammonia proved to be more toxic than the herbicide Imazamox, in both short and chronic bioassays. Urea was the less toxic chemical for both species. The hypogean species was more sensitive than the epigean one to all chemicals. For both species and for all tested chemicals, acute lethality and chronic lethality were induced at concentrations higher than the law limits of good water body quality in Europe, except for ionized ammonia, which provoked the chronic lethality of the hypogean species at a lower concentration. The hazardous concentration (HC) of un-ionized ammonia for 5 % of freshwater copepods, obtained by a species sensitivity distribution, was 92 μg l(-1), significantly lower than the HC computed

  6. Freshwater wetlands for wastewater management: environmental assessment handbook

    SciTech Connect

    Not Available

    1985-09-01

    The Freshwater Wetlands Handbook provides institutional, scientific and engineering guidance for the use of natural, freshwater wetlands for wastewater management. Wetlands have long been recognized for their pollutant removal capabilities and many have been used for wastewater management for some time. Little technical or institutional guidance currently exists for regulating these systems or for planning new systems. This Handbook provides guidance for state and federal regulatory agencies and potential dischargers evaluating wetlands for wastewater disposal or pollutant removal.

  7. UAV-based hyperspectral monitoring of small freshwater area

    NASA Astrophysics Data System (ADS)

    Pölönen, I.; Puupponen, H.-H.; Honkavaara, Eija; Lindfors, A.; Saari, H.; Markelin, L.; Hakala, T.; Nurminen, K.

    2014-10-01

    Recent development in compact, lightweight hyperspectral imagers have enabled UAV-based remote sensing with reasonable costs. We used small hyperspectral imager based on Fabry-Perot interferometer for monitoring small freshwater area in southern Finland. In this study we shortly describe the utilized technology and the field studies performed. We explain processing pipeline for gathered spectral data and introduce target detection-based algorithm for estimating levels of algae, aquatic chlorophyll and turbidity in freshwater. Certain challenges we faced are pointed out.

  8. Restricted-Range Fishes and the Conservation of Brazilian Freshwaters

    PubMed Central

    Nogueira, Cristiano; Buckup, Paulo A.; Menezes, Naercio A.; Oyakawa, Osvaldo T.; Kasecker, Thais P.; Ramos Neto, Mario B.; da Silva, José Maria C.

    2010-01-01

    Background Freshwaters are the most threatened ecosystems on earth. Although recent assessments provide data on global priority regions for freshwater conservation, local scale priorities remain unknown. Refining the scale of global biodiversity assessments (both at terrestrial and freshwater realms) and translating these into conservation priorities on the ground remains a major challenge to biodiversity science, and depends directly on species occurrence data of high taxonomic and geographic resolution. Brazil harbors the richest freshwater ichthyofauna in the world, but knowledge on endemic areas and conservation in Brazilian rivers is still scarce. Methodology/Principal Findings Using data on environmental threats and revised species distribution data we detect and delineate 540 small watershed areas harboring 819 restricted-range fishes in Brazil. Many of these areas are already highly threatened, as 159 (29%) watersheds have lost more than 70% of their original vegetation cover, and only 141 (26%) show significant overlap with formally protected areas or indigenous lands. We detected 220 (40%) critical watersheds overlapping hydroelectric dams or showing both poor formal protection and widespread habitat loss; these sites harbor 344 endemic fish species that may face extinction if no conservation action is in place in the near future. Conclusions/Significance We provide the first analysis of site-scale conservation priorities in the richest freshwater ecosystems of the globe. Our results corroborate the hypothesis that freshwater biodiversity has been neglected in former conservation assessments. The study provides a simple and straightforward method for detecting freshwater priority areas based on endemism and threat, and represents a starting point for integrating freshwater and terrestrial conservation in representative and biogeographically consistent site-scale conservation strategies, that may be scaled-up following naturally linked drainage systems

  9. Activated chemical defenses suppress herbivory on freshwater red algae.

    PubMed

    Goodman, Keri M; Hay, Mark E

    2013-04-01

    The rapid life cycles of freshwater algae are hypothesized to suppress selection for chemical defenses against herbivores, but this notion remains untested. Investigations of chemical defenses are rare for freshwater macrophytes and absent for freshwater red algae. We used crayfish to assess the palatability of five freshwater red algae relative to a palatable green alga and a chemically defended aquatic moss. We then assessed the roles of structural, nutritional, and chemical traits in reducing palatability. Both native and non-native crayfish preferred the green alga Cladophora glomerata to four of the five red algae. Batrachospermum helminthosum, Kumanoa holtonii, and Tuomeya americana employed activated chemical defenses that suppressed feeding by 30-60 % following damage to algal tissues. Paralemanea annulata was defended by its cartilaginous structure, while Boldia erythrosiphon was palatable. Activated defenses are thought to reduce ecological costs by expressing potent defenses only when actually needed; thus, activation might be favored in freshwater red algae whose short-lived gametophytes must grow and reproduce rapidly over a brief growing season. The frequency of activated chemical defenses found here (three of five species) is 3-20× higher than for surveys of marine algae or aquatic vascular plants. If typical for freshwater red algae, this suggests that (1) their chemical defenses may go undetected if chemical activation is not considered and (2) herbivory has been an important selective force in the evolution of freshwater Rhodophyta. Investigations of defenses in freshwater rhodophytes contribute to among-system comparisons and provide insights into the generality of plant-herbivore interactions and their evolution. PMID:23011851

  10. Stormwater runoff drives viral community composition changes in inland freshwaters

    PubMed Central

    Williamson, Kurt E.; Harris, Jamie V.; Green, Jasmin C.; Rahman, Faraz; Chambers, Randolph M.

    2014-01-01

    Storm events impact freshwater microbial communities by transporting terrestrial viruses and other microbes to freshwater systems, and by potentially resuspending microbes from bottom sediments. The magnitude of these impacts on freshwater ecosystems is unknown and largely unexplored. Field studies carried out at two discrete sites in coastal Virginia (USA) were used to characterize the viral load carried by runoff and to test the hypothesis that terrestrial viruses introduced through stormwater runoff change the composition of freshwater microbial communities. Field data gathered from an agricultural watershed indicated that primary runoff can contain viral densities approximating those of receiving waters. Furthermore, viruses attached to suspended colloids made up a large fraction of the total load, particularly in early stages of the storm. At a second field site (stormwater retention pond), RAPD-PCR profiling showed that the viral community of the pond changed dramatically over the course of two intense storms while relatively little change was observed over similar time scales in the absence of disturbance. Comparisons of planktonic and particle-associated viral communities revealed two completely distinct communities, suggesting that particle-associated viruses represent a potentially large and overlooked portion of aquatic viral abundance and diversity. Our findings show that stormwater runoff can quickly change the composition of freshwater microbial communities. Based on these findings, increased storms in the coastal mid-Atlantic region predicted by most climate change models will likely have important impacts on the structure and function of local freshwater microbial communities. PMID:24672520

  11. Electromagnetic methods for mapping freshwater lenses on Micronesian atoll islands

    USGS Publications Warehouse

    Anthony, S.S.

    1992-01-01

    The overall shape of freshwater lenses can be determined by applying electromagnetic methods and inverse layered-earth modeling to the mapping of atoll island freshwater lenses. Conductivity profiles were run across the width of the inhabited islands at Mwoakilloa, Pingelap, and Sapwuahfik atolls of the Pohnpei State, Federated States of Micronesia using a dual-loop, frequency-domain, electromagnetic profiling system. Six values of apparent conductivity were recorded at each sounding station and were used to interpret layer conductivities and/or thicknesses. A three-layer model that includes the unsaturated, freshwater, and saltwater zones was used to simulate apparent-conductivity data measured in the field. Interpreted results were compared with chloride-concentration data from monitoring wells and indicate that the interface between freshwater and saltwater layers, defined from electromagnetic data, is located in the upper part of the transition zone, where the chloride-concentration profile shows a rapid increase with depth. The electromagnetic method can be used to interpret the thickness of the freshwater between monitoring wells, but can not be used to interpret the thickness of freshwater from monitoring wells to the margin of an island. ?? 1992.

  12. Deep-ocean origin of the freshwater eels.

    PubMed

    Inoue, Jun G; Miya, Masaki; Miller, Michael J; Sado, Tetsuya; Hanel, Reinhold; Hatooka, Kiyotaka; Aoyama, Jun; Minegishi, Yuki; Nishida, Mutsumi; Tsukamoto, Katsumi

    2010-06-23

    Of more than 800 species of eels of the order Anguilliformes, only freshwater eels (genus Anguilla with 16 species plus three subspecies) spend most of their lives in freshwater during their catadromous life cycle. Nevertheless, because their spawning areas are located offshore in the open ocean, they migrate back to their specific breeding places in the ocean, often located thousands of kilometres away. The evolutionary origin of such enigmatic behaviour, however, remains elusive because of the uncertain phylogenetic position of freshwater eels within the principally marine anguilliforms. Here, we show strong evidence for a deep oceanic origin of the freshwater eels, based on the phylogenetic analysis of whole mitochondrial genome sequences from 56 species representing all of the 19 anguilliform families. The freshwater eels occupy an apical position within the anguilliforms, forming a highly supported monophyletic group with various oceanic midwater eel species. Moreover, reconstruction of the growth habitats on the resulting tree unequivocally indicates an origination of the freshwater eels from the midwater of the deep ocean. This shows significant concordance with the recent collection of mature adults of the Japanese eel in the upper midwater of the Pacific, suggesting that they have retained their evolutionary origin as a behavioural trait in their spawning areas. PMID:20053660

  13. Toxicity testing of freshwater sediment collected near freshwater aquaculture facilities in the Maritimes, Canada.

    PubMed

    Lalonde, B A; Garron, C; Ernst, B; Jackman, P

    2013-01-01

    In the Atlantic region of Canada, there are close to 50 land-based freshwater aquaculture facilities, most of which discharge wastewater to freshwater receiving environments. This study was designed to assess the chemical and toxicological characteristics of sediments in those receiving environments. Thirty sediment samples were collected from 3 locations (upstream, outfall and downstream) at seven freshwater aquaculture facilities. Toxicity tests conducted included amphipod growth, amphipod survival and Microtox™. Sediments were also analysed for ammonia/porewater ammonia, redox and sulphide. Porewater ammonia concentration for the amphipod survival test ranged from 0.01 to 42 mg/L at the conclusion of the 14-day survival test. Ammonia concentration in sediment ranged from 0.3-202 μg/g, sulphide concentration ranged from 0.15 to 17.4 μg/g, yet redox ranged from 32 to 594 mV. Microtox™  IC50 values ranged from 108,00 to >164,000 mg/L, yet amphipod survival ranged from 0 to 100%, depending on sampling locations. Amphipod survival was significantly related (P < 0.05) to porewater ammonia (at time = 0 and 14 days) and Microtox™  IC50 was significantly related (P < 0.05) to ammonia, sulphide and redox levels. These results indicate that discharges from some the land-based aquaculture facilities are impacting sediment dwelling benthic invertebrates at the outfall but that impact largely disappears by 100 m downstream. Furthermore those impacts were rarely detected during the early winter season, when biomass production was at the lowest. PMID:23705607

  14. Predicting spatial similarity of freshwater fish biodiversity

    PubMed Central

    Azaele, Sandro; Muneepeerakul, Rachata; Maritan, Amos; Rinaldo, Andrea; Rodriguez-Iturbe, Ignacio

    2009-01-01

    A major issue in modern ecology is to understand how ecological complexity at broad scales is regulated by mechanisms operating at the organismic level. What specific underlying processes are essential for a macroecological pattern to emerge? Here, we analyze the analytical predictions of a general model suitable for describing the spatial biodiversity similarity in river ecosystems, and benchmark them against the empirical occurrence data of freshwater fish species collected in the Mississippi–Missouri river system. Encapsulating immigration, emigration, and stochastic noise, and without resorting to species abundance data, the model is able to reproduce the observed probability distribution of the Jaccard similarity index at any given distance. In addition to providing an excellent agreement with the empirical data, this approach accounts for heterogeneities of different subbasins, suggesting a strong dependence of biodiversity similarity on their respective climates. Strikingly, the model can also predict the actual probability distribution of the Jaccard similarity index for any distance when considering just a relatively small sample. The proposed framework supports the notion that simplified macroecological models are capable of predicting fundamental patterns—a theme at the heart of modern community ecology. PMID:19359481

  15. Survey design for detecting rare freshwater mussels

    USGS Publications Warehouse

    Smith, D.R.

    2006-01-01

    A common objective when surveying freshwater mussels is to detect the presence of rare populations. In certain situations, such as when endangered or threatened species are potentially in the area of a proposed impact, the survey should be designed to ensure a high probability of detecting species presence. Linking survey design to probability of detecting species presence has been done for quantitative surveys, but commonly applied designs that are based on timed searches have not made that connection. I propose a semiquantitative survey design that links search area and search efficiency to probability of detecting species presence. The survey can be designed to protect against failing to detect populations above a threshold abundance (or density). I illustrate the design for surveys to detect clubshell (Pluerobema clava) and northern riffleshell (Epioblasma torulosa rangiana) in the Allegheny River. Monte Carlo simulation indicated that the proposed survey design performs well under a range of spatial distributions and low densities (<0.05 m2) where search area is sufficient to ensure that the probability of detecting species presence is predicted to be ???0.85. ?? 2006 by The North American Benthological Society.

  16. Forests fuel fish growth in freshwater deltas

    PubMed Central

    Tanentzap, Andrew J.; Szkokan-Emilson, Erik J.; Kielstra, Brian W.; Arts, Michael T.; Yan, Norman D.; Gunn, John M.

    2014-01-01

    Aquatic ecosystems are fuelled by biogeochemical inputs from surrounding lands and within-lake primary production. Disturbances that change these inputs may affect how aquatic ecosystems function and deliver services vital to humans. Here we test, using a forest cover gradient across eight separate catchments, whether disturbances that remove terrestrial biomass lower organic matter inputs into freshwater lakes, thereby reducing food web productivity. We focus on deltas formed at the stream-lake interface where terrestrial-derived particulate material is deposited. We find that organic matter export increases from more forested catchments, enhancing bacterial biomass. This transfers energy upwards through communities of heavier zooplankton, leading to a fourfold increase in weights of planktivorous young-of-the-year fish. At least 34% of fish biomass is supported by terrestrial primary production, increasing to 66% with greater forest cover. Habitat tracers confirm fish were closely associated with individual catchments, demonstrating that watershed protection and restoration increase biomass in critical life-stages of fish. PMID:24915965

  17. The freshwater artisanal fishery of Patos Lagoon.

    PubMed

    Ceni, G; Fontoura, N F; Cabral, H N

    2016-07-01

    In this study data relative to the fishery in the freshwater area of the Patos Lagoon are analysed, and the dynamics, fishing gears used and catches evaluated. The results reveal the existence of two fishery strategies: forbidden mesh size gillnets (FMG; <35 mm; square measure) and allowed mesh size gillnets (AMG; ≥35 mm; square measure). In total, 31 species were caught (AMG = 27 and FMG = 24), but selectivity due to mesh size was significant (P < 0·001). The FMG may be very harmful since it captures individuals of most species below size at first maturity, including the target species, the armoured catfish Loricariichthys anus (61% of the total catch). In addition, this gear is used throughout the year, including the closed season (CS; November to January), when the target species is reproducing. Target species for the AMG are larger in size, comprising mainly the mullet Mugil liza, the marine catfish Genidens barbus and the whitemouth croaker Micropogonias furnieri. AMS gillnets were not used during the CS. The use of FMG reveals the need for effective fishery law enforcement and the need for additional studies to assess the status of populations of the exploited species. PMID:27250698

  18. Actinide behavior in a freshwater pond

    SciTech Connect

    Trabalka, J.R.; Bogle, M.A.; Scott, T.G.

    1983-01-01

    Long-term investigations of solution chemistry in an alkaline freshwater pond have revealed that actinide oxidation state behavior, particularly that of plutonium, is complex. The Pu(V,VI) fraction was predominant in solution, but it varied over the entire range reported from other natural aquatic environments, in this case, as a result of intrinsic biological and chemical cycles (redox and pH-dependent phenomena). A strong positive correlation between plutonium (Pu), but not uranium (U), and hydroxyl ion over the observation period, especially when both were known to be in higher oxidation states, was particularly notable. Coupled with other examples of divergent U and Pu behavior, this result suggests that Pu(V), or perhaps a mixture of Pu(V,VI), was the prevalent oxidation state in solution. Observations of trivalent actinide sorption behavior during an algal bloom, coupled with the association with a high-molecular weight (nominally 6000 to 10,000 mol wt) organic fraction in solution, indicate that solution-detritus cycling of organic carbon, in turn, may be the primary mechanism in amercium-curium (Am-Cm) cycling. Sorption by sedimentary materials appears to predominate over other factors controlling effective actinide solubility and may explain, at least partially, the absence of an expected strong positive correlation between carbonate and dissolved U. 49 references, 6 figures, 12 tables.

  19. Methane cycling in a tidal freshwater swamp

    SciTech Connect

    Megonigal, J.P.; Schlesinger, W.H. )

    1993-06-01

    Previous studies of methanogenesis in a tidal freshwater swamp on the North Carolina coast have found that potential rates of methane production overestimate observed rates of methane flux, especially during summer months. This research investigates three possibilities for the unexplained losses: methane oxidation, lateral export of dissolved methane to the adjacent river, and ebullition. It is possible that each of these sinks increase during the summer. The potential for methane oxidation was demonstrated in intact soil cores incubated for 21 hours under a 0.5% CH[sub 3]F atmosphere. Methane flux increased from 10+/-27 (mean+/-sd) to 60+/-3 mg m[sup [minus]2] d[sup [minus]1] in treated cores; control core fluxes were 15+/-3 and 19+/-3 mg m[sup [minus]2] d[sup [minus]1] over the same periods. Incubations of slightly unsaturated soils with [sup 14]CH[sub 4] confirmed rapid potential rates of methane oxidation.

  20. Biomass of freshwater turtles: a geographic comparison

    SciTech Connect

    Congdon, J.D.; Greene, J.L.; Gibbons, J.W.

    1986-01-01

    Standing crop biomass of freshwater turtles and minimum annual biomass of egg production were calculated for marsh and farm pond habitats in South Caroling and in Michigan. The species in South Carolina included Chelydra serpentina, Deirochelys reticularia, Kinosternon subrubrum, Pseudemys floridana, P. scripta and Sternotherus odoratus. The species in Michigan were Chelydra serpentina, Chrysemys picta and Emydoidea blandingi. Biomass was also determined for a single species population of P. scripta on a barrier island near Charleston, South Carolina. Population density and biomass of Pseudemys scripta in Green Pond on Capers Island were higher than densities and biomass of the entire six-species community studied on the mainland. In both the farm pond and marsh habitat in South Carolina P. scripta was the numerically dominant species and had the highest biomass. In Michigan, Chrysemys picta was the numerically dominant species; however, the biomass of Chelydra serpentina was higher. The three-species community in Michigan in two marshes (58 kg ha/sup -1/ and 46 kg ha/sup -1/) and farm ponds (23 kg ha/sup -1/) had lower biomasses than did the six-species community in a South Carolina marsh (73 kg/sup -1/). Minimum annual egg production by all species in South Carolina averaged 1.93 kg ha/sup -1/ and in Michigan averaged 2.89 kg ha/sup -1/ of marsh.

  1. 2007 NWFSC Tidal Freshwater Genetics Results

    SciTech Connect

    David Teel

    2008-03-18

    Genetic Analysis of Juvenile Chinook Salmon for inclusion in 'Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, lower Columbia River, 2007. Final report submitted to the Bonneville Power Administration, Contract DE-AC05-76RLO1830.' Genotypic data were collected for 108 Chinook salmon and used in the genetic stock identification analysis. Results of the mixture analysis are presented in Table 1. Percentage estimates for four genetic stock groups (West Cascade Tributary Fall, Willamette River Spring, Deschutes River Fall, and Upper Columbia River Summer/Fall) ranged from 11% to 43%, all with non-zero lower 95% confidence intervals. Small contributions were also estimated for the West Cascade Tributary Spring (3%) and Snake River Fall (6%) stock groups. Results of individual fish probability assignments were summed by collection date (Figure 1) and site (Figure 2). Assignment probabilities for the most likely stock group for each individual ranged from 0.51 to 1.00 with approximately 60% of the assignments greater than 0.90 (data not shown). Nearly all of the low probability assignments were fish with assignments split between the Deschutes River Fall and Upper Columbia River Summer/Fall groups.

  2. Forests fuel fish growth in freshwater deltas.

    PubMed

    Tanentzap, Andrew J; Szkokan-Emilson, Erik J; Kielstra, Brian W; Arts, Michael T; Yan, Norman D; Gunn, John M

    2014-01-01

    Aquatic ecosystems are fuelled by biogeochemical inputs from surrounding lands and within-lake primary production. Disturbances that change these inputs may affect how aquatic ecosystems function and deliver services vital to humans. Here we test, using a forest cover gradient across eight separate catchments, whether disturbances that remove terrestrial biomass lower organic matter inputs into freshwater lakes, thereby reducing food web productivity. We focus on deltas formed at the stream-lake interface where terrestrial-derived particulate material is deposited. We find that organic matter export increases from more forested catchments, enhancing bacterial biomass. This transfers energy upwards through communities of heavier zooplankton, leading to a fourfold increase in weights of planktivorous young-of-the-year fish. At least 34% of fish biomass is supported by terrestrial primary production, increasing to 66% with greater forest cover. Habitat tracers confirm fish were closely associated with individual catchments, demonstrating that watershed protection and restoration increase biomass in critical life-stages of fish. PMID:24915965

  3. Synergistic allelochemicals from a freshwater cyanobacterium

    PubMed Central

    Leão, Pedro N.; Pereira, Alban R.; Liu, Wei-Ting; Ng, Julio; Pevzner, Pavel A.; Dorrestein, Pieter C.; König, Gabriele M.; Vasconcelos, Vitor M.; Gerwick, William H.

    2010-01-01

    The ability of cyanobacteria to produce complex secondary metabolites with potent biological activities has gathered considerable attention due to their potential therapeutic and agrochemical applications. However, the precise physiological or ecological roles played by a majority of these metabolites have remained elusive. Several studies have shown that cyanobacteria are able to interfere with other organisms in their communities through the release of compounds into the surrounding medium, a phenomenon usually referred to as allelopathy. Exudates from the freshwater cyanobacterium Oscillatoria sp. had previously been shown to inhibit the green microalga Chlorella vulgaris. In this study, we observed that maximal allelopathic activity is highest in early growth stages of the cyanobacterium, and this provided sufficient material for isolation and chemical characterization of active compounds that inhibited the growth of C. vulgaris. Using a bioassay-guided approach, we isolated and structurally characterized these metabolites as cyclic peptides containing several unusually modified amino acids that are found both in the cells and in the spent media of Oscillatoria sp. cultures. Strikingly, only the mixture of the two most abundant metabolites in the cells was active toward C. vulgaris. Synergism was also observed in a lung cancer cell cytotoxicity assay. The binary mixture inhibited other phytoplanktonic organisms, supporting a natural function of this synergistic mixture of metabolites as allelochemicals. PMID:20534563

  4. Flavobacterium procerum sp. nov., isolated from freshwater.

    PubMed

    Feng, Qingqing; Han, Lu; Yuan, Xin; Tan, Xu; Gao, Yuan; Lv, Jie

    2015-08-01

    A Gram-reaction-negative, strictly aerobic, yellow-pigmented, rod-shaped bacterium, designated strain T3T, was isolated from freshwater of Chishui River flowing through Maotai town, Guizhou, south-west China. Analysis of the16S rRNA gene sequence indicated that strain T3T was a member of the genus Flavobacterium and closely related to Flavobacterium resistens DSM 19382T (96.8 %). The novel strain was able to grow at 10-34 °C (optimum 28 °C), pH 6.0-11.0 (optimum pH 8.0-9.0) and with 0-2.0 % (w/v) NaCl (optimum 0 %). The major polar lipids were phosphatidylethanolamine, two unknown glycolipids, five unknown aminolipids and four unidentified lipids, and the major respiratory quinone was MK-6. The predominant fatty acids were C16  :  1ω7c and/or C16  :  1ω6c and iso-C15  :  0. The DNA G+C content of the strain was 36 mol  %. Based on these data, strain T3T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium procerum sp. nov. is proposed. The type strain is T3T ( = CGMCC 1.12926T = JCM 30113T). PMID:25969476

  5. Large-scale degradation of Amazonian freshwater ecosystems.

    PubMed

    Castello, Leandro; Macedo, Marcia N

    2016-03-01

    Hydrological connectivity regulates the structure and function of Amazonian freshwater ecosystems and the provisioning of services that sustain local populations. This connectivity is increasingly being disrupted by the construction of dams, mining, land-cover changes, and global climate change. This review analyzes these drivers of degradation, evaluates their impacts on hydrological connectivity, and identifies policy deficiencies that hinder freshwater ecosystem protection. There are 154 large hydroelectric dams in operation today, and 21 dams under construction. The current trajectory of dam construction will leave only three free-flowing tributaries in the next few decades if all 277 planned dams are completed. Land-cover changes driven by mining, dam and road construction, agriculture and cattle ranching have already affected ~20% of the Basin and up to ~50% of riparian forests in some regions. Global climate change will likely exacerbate these impacts by creating warmer and dryer conditions, with less predictable rainfall and more extreme events (e.g., droughts and floods). The resulting hydrological alterations are rapidly degrading freshwater ecosystems, both independently and via complex feedbacks and synergistic interactions. The ecosystem impacts include biodiversity loss, warmer stream temperatures, stronger and more frequent floodplain fires, and changes to biogeochemical cycles, transport of organic and inorganic materials, and freshwater community structure and function. The impacts also include reductions in water quality, fish yields, and availability of water for navigation, power generation, and human use. This degradation of Amazonian freshwater ecosystems cannot be curbed presently because existing policies are inconsistent across the Basin, ignore cumulative effects, and overlook the hydrological connectivity of freshwater ecosystems. Maintaining the integrity of these freshwater ecosystems requires a basinwide research and policy framework

  6. New Zealand Freshwater Management: Changing Policy for a Changing World

    NASA Astrophysics Data System (ADS)

    Rouse, H. L.; Norton, N.

    2014-12-01

    Fresh water is essential to New Zealand's economic, environmental, cultural and social well-being. In line with global trends, New Zealand's freshwater resources are under pressure from increased abstraction and changes in land-use which contribute contaminants to our freshwater systems. Recent central government policy reform introduces greater national direction and guidance, to bring about a step-change in freshwater management. An existing national policy for freshwater management introduced in 2011 requires regional authorities to produce freshwater management plans containing clear freshwater objectives (measurable statements about the desired environmental state for water bodies) and associated limits to resource use (such as environmental flows and quantity allocation limits, and loads of contaminants to be discharged). These plans must integrate water quantity and quality management, consider climate change, and incorporate tangata whenua (New Zealand māori) roles and interests. In recent (2014) national policy amendments, the regional authorities are also required to implement national 'bottom-line' standards for certain attributes of the system to be managed; undertake accounting for all water takes and all sources of contaminants; and to develop and implement their plans in a collaborative way with communities. This rapid change in national policy has necessitated a new way of working for authorities tasked with implementation; many obstacles lie in their path. The scientific methods required to help set water quantity limits are well established, but water quality methods are less so. Collaborative processes have well documented benefits but also raise many challenges, particularly for the communication of complex and often uncertain scientific information. This paper provides background on the national policy changes and offers some early lessons learned by the regional authorities implementing collaborative freshwater management in New Zealand.

  7. Mechanical challenges to freshwater residency in sharks and rays.

    PubMed

    Gleiss, Adrian C; Potvin, Jean; Keleher, James J; Whitty, Jeff M; Morgan, David L; Goldbogen, Jeremy A

    2015-04-01

    Major transitions between marine and freshwater habitats are relatively infrequent, primarily as a result of major physiological and ecological challenges. Few species of cartilaginous fish have evolved to occupy freshwater habitats. Current thought suggests that the metabolic physiology of sharks has remained a barrier to the diversification of this taxon in freshwater ecosystems. Here, we demonstrate that the physical properties of water provide an additional constraint for this species-rich group to occupy freshwater systems. Using hydromechanical modeling, we show that occurrence in fresh water results in a two- to three-fold increase in negative buoyancy for sharks and rays. This carries the energetic cost of lift production and results in increased buoyancy-dependent mechanical power requirements for swimming and increased optimal swim speeds. The primary source of buoyancy, the lipid-rich liver, offers only limited compensation for increased negative buoyancy as a result of decreasing water density; maintaining the same submerged weight would involve increasing the liver volume by very large amounts: 3- to 4-fold in scenarios where liver density is also reduced to currently observed minimal levels and 8-fold without any changes in liver density. The first data on body density from two species of elasmobranch occurring in freshwater (the bull shark Carcharhinus leucas, Müller and Henle 1839, and the largetooth sawfish Pristis pristis, Linnaeus 1758) support this hypothesis, showing similar liver sizes as marine forms but lower liver densities, but the greatest negative buoyancies of any elasmobranch studied to date. Our data suggest that the mechanical challenges associated with buoyancy control may have hampered the invasion of freshwater habitats in elasmobranchs, highlighting an additional key factor that may govern the predisposition of marine organisms to successfully establish in freshwater habitats. PMID:25573824

  8. Anthropogenic litter in urban freshwater ecosystems: distribution and microbial interactions.

    PubMed

    Hoellein, Timothy; Rojas, Miguel; Pink, Adam; Gasior, Joseph; Kelly, John

    2014-01-01

    Accumulation of anthropogenic litter (i.e. garbage; AL) and its ecosystem effects in marine environments are well documented. Rivers receive AL from terrestrial habitats and represent a major source of AL to marine environments, but AL is rarely studied within freshwater ecosystems. Our objectives were to 1) quantify AL density in urban freshwaters, 2) compare AL abundance among freshwater, terrestrial, and marine ecosystems, and 3) characterize the activity and composition of AL biofilms in freshwater habitats. We quantified AL from the Chicago River and Chicago's Lake Michigan shoreline, and found that AL abundance in Chicago freshwater ecosystems was comparable to previously reported data for marine and terrestrial ecosystems, although AL density and composition differed among habitats. To assess microbial interactions with AL, we incubated AL and natural substrates in 3 freshwater ecosystems, quantified biofilm metabolism as gross primary production (GPP) and community respiration (CR), and characterized biofilm bacterial community composition via high-throughput sequencing of 16S rRNA genes. The main driver of biofilm community composition was incubation location (e.g., river vs pond), but there were some significant differences in biofilm composition and metabolism among substrates. For example, biofilms on organic substrates (cardboard and leaves) had lower GPP than hard substrates (glass, plastic, aluminum and tiles). In addition, bacterial communities on organic substrates were distinct in composition from those on hard substrates, with higher relative abundances of bacteria associated with cellulose decomposition. Finally, we used our results to develop a conceptual diagram designed to unite the study of AL in terrestrial and freshwater environments with the well-established field of marine debris research. We suggest this broad perspective will be useful for future studies which synthesize AL sources, ecosystem effects, and fate across multiple ecosystem

  9. Anthropogenic Litter in Urban Freshwater Ecosystems: Distribution and Microbial Interactions

    PubMed Central

    Hoellein, Timothy; Rojas, Miguel; Pink, Adam; Gasior, Joseph; Kelly, John

    2014-01-01

    Accumulation of anthropogenic litter (i.e. garbage; AL) and its ecosystem effects in marine environments are well documented. Rivers receive AL from terrestrial habitats and represent a major source of AL to marine environments, but AL is rarely studied within freshwater ecosystems. Our objectives were to 1) quantify AL density in urban freshwaters, 2) compare AL abundance among freshwater, terrestrial, and marine ecosystems, and 3) characterize the activity and composition of AL biofilms in freshwater habitats. We quantified AL from the Chicago River and Chicago's Lake Michigan shoreline, and found that AL abundance in Chicago freshwater ecosystems was comparable to previously reported data for marine and terrestrial ecosystems, although AL density and composition differed among habitats. To assess microbial interactions with AL, we incubated AL and natural substrates in 3 freshwater ecosystems, quantified biofilm metabolism as gross primary production (GPP) and community respiration (CR), and characterized biofilm bacterial community composition via high-throughput sequencing of 16S rRNA genes. The main driver of biofilm community composition was incubation location (e.g., river vs pond), but there were some significant differences in biofilm composition and metabolism among substrates. For example, biofilms on organic substrates (cardboard and leaves) had lower GPP than hard substrates (glass, plastic, aluminum and tiles). In addition, bacterial communities on organic substrates were distinct in composition from those on hard substrates, with higher relative abundances of bacteria associated with cellulose decomposition. Finally, we used our results to develop a conceptual diagram designed to unite the study of AL in terrestrial and freshwater environments with the well-established field of marine debris research. We suggest this broad perspective will be useful for future studies which synthesize AL sources, ecosystem effects, and fate across multiple ecosystem

  10. Simulating Freshwater Availability under Future Climate Conditions

    NASA Astrophysics Data System (ADS)

    Zhao, F.; Zeng, N.; Motesharrei, S.; Gustafson, K. C.; Rivas, J.; Miralles-Wilhelm, F.; Kalnay, E.

    2013-12-01

    Freshwater availability is a key factor for regional development. Precipitation, evaporation, river inflow and outflow are the major terms in the estimate of regional water supply. In this study, we aim to obtain a realistic estimate for these variables from 1901 to 2100. First we calculated the ensemble mean precipitation using the 2011-2100 RCP4.5 output (re-sampled to half-degree spatial resolution) from 16 General Circulation Models (GCMs) participating the Coupled Model Intercomparison Project Phase 5 (CMIP5). The projections are then combined with the half-degree 1901-2010 Climate Research Unit (CRU) TS3.2 dataset after bias correction. We then used the combined data to drive our UMD Earth System Model (ESM), in order to generate evaporation and runoff. We also developed a River-Routing Scheme based on the idea of Taikan Oki, as part of the ESM. It is capable of calculating river inflow and outflow for any region, driven by the gridded runoff output. River direction and slope information from Global Dominant River Tracing (DRT) dataset are included in our scheme. The effects of reservoirs/dams are parameterized based on a few simple factors such as soil moisture, population density and geographic regions. Simulated river flow is validated with river gauge measurements for the world's major rivers. We have applied our river flow calculation to two data-rich watersheds in the United States: Phoenix AMA watershed and the Potomac River Basin. The results are used in our SImple WAter model (SIWA) to explore water management options.

  11. Freshwater ecosystems--structure and response.

    PubMed

    Jones, J G

    2001-10-01

    Before it is possible to predict the impact of human activities on the natural environment it is necessary to understand the forces that drive and, therefore, control that environment. This paper is concerned with the freshwater component of the aquatic environment. The driving forces involved (some of which are under man's control) can be divided into the physical and the chemical, but the response is, almost entirely, biological. Although most impacts of the food processing industry might be perceived to be on running waters, this is not always the case, but we can apply the same basic rules to both static and running waters. The physical forces that determine how a lake functions are as follows. In early spring, in the temperate zone, the temperature of the surface water in lakes rises and the sunlight input increases. This results in stratification of the water body. The cooler, deeper water is separated, physically, by gravity. This isolated water plays a very different role in the function of the lake and is analogous to how a river works. Man's activities drive these systems by our input of inorganic and organic substances. The inorganic inputs, particularly of phosphorous, stimulate undesirable algal growths, some of which may produce particularly dangerous toxins. We must now accept that climate change, driven by man, will exacerbate these problems. Organic inputs from the food industry, i.e., carbohydrates, lipids, and proteins, will all impact lakes and rivers by increasing the biological oxygen demand. The worst case scenario is total loss of oxygen from the water as a result of microbial activity. Lipids create the greatest oxygen demand but carbohydrates (more easily biodegradable) also result in unsightly "sewage fungus." Protein waste can be degraded to produce ammonia and sulfide, both of which produce toxicity problems. Bioremediation processes, particularly phytoremediation, can alleviate these problems in a cost-effective manner and this paper

  12. Behavior of technetium in freshwater environments

    SciTech Connect

    Blaylock, B.G.; Frank, M.L.; Hoffman, F.O.; DeAngelis, D.L.

    1984-01-01

    In a previous study, /sup 95m/Tc, as a pertechnetate, was released to a small, experimental, freshwater pond, and the concentrations were determined in biotic and abiotic components of the pond ecosystem. A simple mathematical model was developed to predict the concentration of /sup 95m/Tc in fish and snails. Results from this study indicated that uptake through the food chain was an important source of technetium to the higher trophic levels (i.e., fish). In the current study, an experimental pond was spiked with /sup 95m/Tc in the pertechnetate form, and the concentrations of /sup 95m/Tc were measured in the lower trophic levels. Emphasis was placed on measuring the concentration of /sup 95m/Tc in zooplankton, benthic invertebrates, and the aquatic macrophyte Elodea canadensis. Fish were excluded from the pond to allow the development of a large zooplankton population. The concentration of /sup 95m/Tc in water decreased from 0.75 Bq/mL 1 h after the pond was spiked, to 0.21 Bq/mL at 20 d. Throughout the experiment, at least 98% of the /sup 95m/Tc in the water was in the dissolved fraction (0.4 ..mu..m). Zooplankton accumulated /sup 95m/Tc rapidly, having concentration factors (Bq/g sample wet wt. divided by Bq/g water) ranging from 3 at 4 h to 36 at 20 d. Concentration factors ranged from 3 to 8 for benthic insects and from 1 to 62 for the aquatic macrophyte.

  13. Flavobacterium buctense sp. nov., isolated from freshwater.

    PubMed

    Feng, Xiao-Min; Tan, Xu; Jia, Li; Long, Ping-Ping; Han, Lu; Lv, Jie

    2015-11-01

    A gram-negative, non-gliding motile, aerobic bacterium, designated as strain T7(T), was isolated from freshwater of Chishui River flowing through Maotai town, Guizhou Province, southwest of China. Based on the 16S rRNA gene sequence analysis, the isolate was identified as a member of the genus Flavobacterium and that shared less than 97 % sequence similarities with recognized Flavobacterium species. Its closest phylogenetic relative was Flavobacterium dankookense (96.9 %), followed by Flavobacterium cheonhonense (96.8 %) and Flavobacterium macrobrachii (96.7 %). The strain formed smooth yellow colonies on R2A plates, and cells were observed to be short rods. Strain T7(T) was found to be able to grow at 15-30 °C (optimum 25 °C), at NaCl concentration of 0-0.5 % (optimum 0 %) and at pH 6.5-9.5 (optimum pH 7.5). Catalase and oxidase tests were positive. Polar lipids of strain T7(T) included phosphatidylethanolamine, four unidentified polar lipids, one unidentified phospholipid and one unidentified aminolipid. Chemotaxonomic analysis revealed menaquinone-6 as the dominant respiratory quinone and C(15:0), iso-C(15:0) and iso-C(15:1) as the major fatty acids. The DNA G+C content of strain T7(T) was determined to be 38.2 mol%. On the basis of phylogenetic, phenotypic and genetic data obtained in this study, strain T7(T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium buctense sp. nov. is proposed. The type strain is T7(T) (=JCM 30750=CGMCC 1.15216). PMID:26374244

  14. Freshwater biodiversity: importance, threats, status and conservation challenges.

    PubMed

    Dudgeon, David; Arthington, Angela H; Gessner, Mark O; Kawabata, Zen-Ichiro; Knowler, Duncan J; Lévêque, Christian; Naiman, Robert J; Prieur-Richard, Anne-Hélène; Soto, Doris; Stiassny, Melanie L J; Sullivan, Caroline A

    2006-05-01

    Freshwater biodiversity is the over-riding conservation priority during the International Decade for Action - 'Water for Life' - 2005 to 2015. Fresh water makes up only 0.01% of the World's water and approximately 0.8% of the Earth's surface, yet this tiny fraction of global water supports at least 100000 species out of approximately 1.8 million - almost 6% of all described species. Inland waters and freshwater biodiversity constitute a valuable natural resource, in economic, cultural, aesthetic, scientific and educational terms. Their conservation and management are critical to the interests of all humans, nations and governments. Yet this precious heritage is in crisis. Fresh waters are experiencing declines in biodiversity far greater than those in the most affected terrestrial ecosystems, and if trends in human demands for water remain unaltered and species losses continue at current rates, the opportunity to conserve much of the remaining biodiversity in fresh water will vanish before the 'Water for Life' decade ends in 2015. Why is this so, and what is being done about it? This article explores the special features of freshwater habitats and the biodiversity they support that makes them especially vulnerable to human activities. We document threats to global freshwater biodiversity under five headings: overexploitation; water pollution; flow modification; destruction or degradation of habitat; and invasion by exotic species. Their combined and interacting influences have resulted in population declines and range reduction of freshwater biodiversity worldwide. Conservation of biodiversity is complicated by the landscape position of rivers and wetlands as 'receivers' of land-use effluents, and the problems posed by endemism and thus non-substitutability. In addition, in many parts of the world, fresh water is subject to severe competition among multiple human stakeholders. Protection of freshwater biodiversity is perhaps the ultimate conservation challenge

  15. Arctic Ocean freshwater as a trigger for abrupt climate change

    NASA Astrophysics Data System (ADS)

    Bradley, Raymond; Condron, Alan; Coletti, Anthony

    2016-04-01

    The cause of the Younger Dryas cooling remains unresolved despite decades of debate. Current arguments focus on either freshwater from Glacial Lake Agassiz drainage through the St Lawrence or the MacKenzie river systems. High resolution ocean modeling suggests that freshwater delivered to the North Atlantic from the Arctic Ocean through Fram Strait would have had more of an impact on Atlantic Meridional Overturning Circulation (AMOC) than freshwater from the St Lawrence. This has been interpreted as an argument for a MacKenzie River /Lake Agassiz freshwater source. However, it is important to note that although the modeling identifies Fram Strait as the optimum location for delivery of freshwater to disrupt the AMOC, this does not mean the freshwater source came from Lake Agassiz. Another potential source of freshwater is the Arctic Ocean ice cover itself. During the LGM, ice cover was extremely thick - many tens of meters in the Canada Basin (at least), resulting in a hiatus in sediment deposition there. Extreme ice thickness was related to a stagnant circulation, very low temperatures and continuous accumulation of snow on top of a base of sea-ice. This resulted in a large accumulation of freshwater in the Arctic Basin. As sea-level rose and a more modern circulation regime became established in the Arctic, this freshwater was released from the Arctic Ocean through Fram Strait, leading to extensive sea-ice formation in the North Atlantic (Greenland Sea) and a major reduction in the AMOC. Here we present new model results and a review of the paleoceanographic evidence to support this hypothesis. The bottom line is that the Arctic Ocean was likely a major player in causing abrupt climate change in the past, via its influence on the AMOC. Although we focus here on the Younger Dryas, the Arctic Ocean has been repeatedly isolated from the world ocean during glacial periods of the past. When these periods of isolation ended, it is probable that there were significant

  16. SGD Flux of Freshwater and Nutrients into the Coastal Area

    NASA Astrophysics Data System (ADS)

    Hatta, M.; Zhang, J.

    2006-12-01

    The estimation of a freshwater discharge plays an important role in understanding interocean fluxes of buoyancy in stabilizing the present-day overturning circulation of heat and salt. Recently, one of the freshwater discharges, a Submarine Groundwater Discharge (SGD), has been recognized as an important worldwide phenomenon that provides direct transport pathways for both water and other materials between the land groundwater system and the marine environment. However, using oceanographic data, the estimation of SGD flux hardly is reported. Especially in the high-latitude marginal sea, an important area for the oceanic circulation, it is difficult to evaluate the flux because this area has plural interfaces to the open ocean, many sources of freshwater and complicated water mass structure. Toyama Bay - semi-closed, the biggest, and the deepest one in the Sea of Japan - is suitable for a model of the estimation. This is due to how the bay has a simple water mass structure, the deep water is related to the abyssal circulation of Japan Sea, and the shallow water is influenced by a huge amount of freshwater, especially SGD, which is distributed widely on the continental shelf. The SGD fluxes of freshwater and nutrients in Toyama Bay were estimated using a box model in this study. The data sources are from the expedition of the T/S Kakuyo Maru in 2003, the R/V Tansei Maru (KT05-11) in 2005, MIRC (Marine Information Research Center, Japan Hydrographic Association), and parts by Toyama Prefectural Fisheries Experimental Station. According to the T-S diagram, the water structure in Toyama Bay was classified into three parts: the costal surface water, Tsushima Warm Current and the deep water. It was clarified that the <200m is composed of high-salinity water mass and the low-salinity water mass formed by the nearshore freshwater. The SGD's freshwater flux, which was calculated by a box model (<200m), was about <30% of the riverine. For the flux of nutrients, P and N are

  17. Taking High Conservation Value from Forests to Freshwaters

    NASA Astrophysics Data System (ADS)

    Abell, Robin; Morgan, Siân K.; Morgan, Alexis J.

    2015-07-01

    The high conservation value (HCV) concept, originally developed by the Forest Stewardship Council, has been widely incorporated outside the forestry sector into companies' supply chain assessments and responsible purchasing policies, financial institutions' investment policies, and numerous voluntary commodity standards. Many, if not most, of these newer applications relate to production practices that are likely to affect freshwater systems directly or indirectly, yet there is little guidance as to whether or how HCV can be applied to water bodies. We focus this paper on commodity standards and begin by exploring how prominent standards currently address both HCVs and freshwaters. We then highlight freshwater features of high conservation importance and examine how well those features are captured by the existing HCV framework. We propose a new set of freshwater `elements' for each of the six values and suggest an approach for identifying HCV Areas that takes out-of-fence line impacts into account, thereby spatially extending the scope of existing methods to define HCVs. We argue that virtually any non-marine HCV assessment, regardless of the production sector, should be expanded to include freshwater values, and we suggest how to put those recommendations into practice.

  18. Bistability of mangrove forests and competition with freshwater plants

    USGS Publications Warehouse

    Jiang, Jiang; Fuller, Douglas O; Teh, Su Yean; Zhai, Lu; Koh, Hock Lye; DeAngelis, Donald L.; Sternberg, L.D.S.L.

    2015-01-01

    Halophytic communities such as mangrove forests and buttonwood hammocks tend to border freshwater plant communities as sharp ecotones. Most studies attribute this purely to underlying physical templates, such as groundwater salinity gradients caused by tidal flux and topography. However, a few recent studies hypothesize that self-reinforcing feedback between vegetation and vadose zone salinity are also involved and create a bistable situation in which either halophytic dominated habitat or freshwater plant communities may dominate as alternative stable states. Here, we revisit the bistability hypothesis and demonstrate the mechanisms that result in bistability. We demonstrate with remote sensing imagery the sharp boundaries between freshwater hardwood hammock communities in southern Florida and halophytic communities such as buttonwood hammocks and mangroves. We further document from the literature how transpiration of mangroves and freshwater plants respond differently to vadose zone salinity, thus altering the salinity through feedback. Using mathematical models, we show how the self-reinforcing feedback, together with physical template, controls the ecotones between halophytic and freshwater communities. Regions of bistability along environmental gradients of salinity have the potential for large-scale vegetation shifts following pulse disturbances such as hurricane tidal surges in Florida, or tsunamis in other regions. The size of the region of bistability can be large for low-lying coastal habitat due to the saline water table, which extends inland due to salinity intrusion. We suggest coupling ecological and hydrologic processes as a framework for future studies.

  19. Freshwater Assessments in Developing Country Contexts: Innovations and Opportunities

    NASA Astrophysics Data System (ADS)

    Abell, R.; Bryer, M.

    2005-05-01

    The world's developed nations have hosted the lion's share of freshwater conservation assessments, yet developing nations are home to a disproportionately large fraction of global freshwater biodiversity. With less `hard-path' infrastructure in place, opportunities for proactive freshwater conservation abound, but economic growth pressures do as well. The need for freshwater assessments is urgent in these environments, but assessment approaches and outcomes can exhibit important differences from those in developed country contexts. First, the need to balance biodiversity conservation with economic development interests is a common and strong undercurrent and translates to an elevated focus on freshwater ecosystem goods and services over pure existence values. Second, data gaps about species, habitats, and processes can be so extensive as to nearly engender paralysis. Assessment methodologies created for data-rich situations often transfer imperfectly to these environments, and planners must find creative ways of circumventing data gaps without sacrificing scientific robustness. In some cases, this need has catalyzed technological `leapfrogging,' with advanced tools developed expressly to address these gaps. Here we present examples of these innovations as applied in South America, with a focus on the use of habitat classifications and threat analyses based on models and geospatial data.

  20. Malacofauna of Holocene freshwater calcareous deposits of Lithuania

    NASA Astrophysics Data System (ADS)

    Sanko, Aleksander; Vainorius, Julius; Melešytė, Monika

    2010-12-01

    The malacofauna of freshwater calcareous deposits of Lithuania was studied. Sections of the Mūšos Tyrelis and Pabaliai peatbogs near the town of Šiauliai, as well as Dubičiai section (three sites) in SE Lithuania and Dūkštos in Central Lithuania were investigated. Freshwater calcareous deposits are attributed to three groups of facies - lacustrine, valley-hollow-peatbog and terrestrial. Each group of facies consists of sub-facies (freshwater lime, "gazha" (limno-calcite), peat-tufa, calcareous tufa, "mada") varying the formation conditions, composition and other characteristics. The mollusc fauna in the lacustrine facies group (Mūšos Tyrelis and Pabaliai sections) is represented by lacustrine species containing euryecological freshwater molluscs. Terrestrial and rheophilous species are rare or absent in the lacustrine group. Deposits of valley-hollow-peatbog facies contain shells of euryecological freshwater and lacustrine molluscs together with rheophyl shells, sometimes with abundant terrestrial shells, as was observed in the Dubičiai-4 section. A characteristic feature of the terrestrial facies group deposits is the occurrence of solely terrestrial mollusc shells (Dūkštos section).

  1. Key roles for freshwater Actinobacteria revealed by deep metagenomic sequencing.

    PubMed

    Ghai, Rohit; Mizuno, Carolina Megumi; Picazo, Antonio; Camacho, Antonio; Rodriguez-Valera, Francisco

    2014-12-01

    Freshwater ecosystems are critical but fragile environments directly affecting society and its welfare. However, our understanding of genuinely freshwater microbial communities, constrained by our capacity to manipulate its prokaryotic participants in axenic cultures, remains very rudimentary. Even the most abundant components, freshwater Actinobacteria, remain largely unknown. Here, applying deep metagenomic sequencing to the microbial community of a freshwater reservoir, we were able to circumvent this traditional bottleneck and reconstruct de novo seven distinct streamlined actinobacterial genomes. These genomes represent three new groups of photoheterotrophic, planktonic Actinobacteria. We describe for the first time genomes of two novel clades, acMicro (Micrococcineae, related to Luna2,) and acAMD (Actinomycetales, related to acTH1). Besides, an aggregate of contigs belonged to a new branch of the Acidimicrobiales. All are estimated to have small genomes (approximately 1.2 Mb), and their GC content varied from 40 to 61%. One of the Micrococcineae genomes encodes a proteorhodopsin, a rhodopsin type reported for the first time in Actinobacteria. The remarkable potential capacity of some of these genomes to transform recalcitrant plant detrital material, particularly lignin-derived compounds, suggests close linkages between the terrestrial and aquatic realms. Moreover, abundances of Actinobacteria correlate inversely to those of Cyanobacteria that are responsible for prolonged and frequently irretrievable damage to freshwater ecosystems. This suggests that they might serve as sentinels of impending ecological catastrophes. PMID:25355242

  2. Impact of freshwater diversion projects on diversity and activity of methanotrophic communities in freshwater wetlands

    NASA Astrophysics Data System (ADS)

    Isaac, J.; Schulz, C. J.; Childers, G. W.

    2009-12-01

    Methanotrophic bacteria are key players in the carbon cycle capable of using methane as a sole carbon and energy source. Methanotrophs are ubiquitous in soil environments and play a key role in decreasing methane flux from anaerobic environments to the atmosphere, reducing the concentration of this greenhouse gas. Wetlands are a particularly important source of methane to the atmosphere, even though methanotrophs can consume the majority of the methane produced. Decreases in methanotrophic activity in wetland environments due to disturbance can have negative impacts with regard to greenhouse gas emissions, especially if the impact is widespread. Currently, several freshwater diversion projects are active and/or scheduled to come online in south Louisiana, delivering freshwater, sediments, and nutrients to coastal wetlands en masse to help combat subsidence and coastal erosion. Along with freshwater, these diversions also deliver other components of the Mississippi River including substantial bicarbonate alkalinity, reactive nitrogen, and sulfate. Analogous to the large scale diversion projects are smaller restoration projects that deliver treated wastewater effluent to wetlands. In particular, the Joyce Wildlife Management Area (JWMA) in southeast Louisiana has been the recipient of ~5 million gallons of treated domestic effluent per day since 2006. Both the composition of the marsh receiving the effluent and the effluent itself have similarities to Mississippi River diversions. We collected pre and post JWMA sediment microbial community DNA and created cloned libraries of genes encoding particulate methane monooxygenase (pmoA) as a proxy for methanotrophic community composition. Water chemistry data was also collected. Shifts in methanotrophic community composition were apparent as well as shifts in water chemistry. The most notable shift in water chemistry was pH, which changed from mildly acidic to slightly alkaline conditions, due to the increased alkalinity of

  3. Multi proxy chemical properties of freshwater sapropel

    NASA Astrophysics Data System (ADS)

    Stankevica, Karina; Rutina, Liga; Burlakovs, Juris; Klavins, Maris

    2014-05-01

    Freshwater sapropel is organic rich lake sediment firstly named "gyttja" by Hampus van Post in 1862. It is composed of organic remains such as shell detritus, plankton, chitin of insects, spores of higher plants and mineral part formed in eutrophic lake environments. The most appropriate environments for the formation of sapropel are in shallow, overgrown post-glacial lakes and valleys of big rivers in boreal zone, while thick deposits of such kind of organic sediments rarely can be found in lakes on permafrost, mountainous regions or areas with increased aridity. Organic lake sediments are divided in 3 classes according the content of organic matter and mineral part: biogenic, clastic and mixed. The value of sapropel as natural resource increases with the content of organic matter and main applications of sapropel are in agriculture, medicine, cosmetic and chemical industry. The research of sapropel in Latvia has shown that the total amount of this natural resource is close to 2 billion m3 or ~500 million tons. Sapropel has fine, dispersed structure and is plastic, but colour due to the high natural content of phosphorus usually is dark blue, later after drying it becomes light blue. Main research of the sapropel nowadays is turned to investigation of interactions among organic and mineral part of the sapropel with living organisms thus giving the inside look in processes and biological activity of the formation. From the chemical point of view sapropel contains lipids (bitumen), water-soluble substances that are readily hydrolyzed, including humic and fulvic acids, cellulose and the residual part, which does not hydrolyze. In this work we have analyzed the class of organic sapropel: peaty, cyanobacterial and green algal types, as well as siliceous sapropel, in order to determine the presence of biologically active substances, including humic substances, proteins and enzymes as well as to check free radical scavenging activity. Samples were collected from lakes

  4. Extinction rates in North American freshwater fishes, 1900-2010

    USGS Publications Warehouse

    Burkhead, Noel M.

    2012-01-01

    Widespread evidence shows that the modern rates of extinction in many plants and animals exceed background rates in the fossil record. In the present article, I investigate this issue with regard to North American freshwater fishes. From 1898 to 2006, 57 taxa became extinct, and three distinct populations were extirpated from the continent. Since 1989, the numbers of extinct North American fishes have increased by 25%. From the end of the nineteenth century to the present, modern extinctions varied by decade but significantly increased after 1950 (post-1950s mean = 7.5 extinct taxa per decade). The modern extinction rate for North American freshwater fishes is conservatively estimated to be 877 times greater than the background extinction rate for freshwater fishes (one extinction every 3 million years). Reasonable estimates project that future increases in extinctions will range from 53 to 86 species by 2050.

  5. New data on freshwater psammic Gastrotricha from Brazil.

    PubMed

    Garraffoni, André R S; Araujo, Thiago Q; Lourenço, Anete P; Balsamo, Maria

    2010-01-01

    Current knowledge of freshwater gastrotrich fauna from Brazil is underestimated as only two studies are available. The present communication is a taxonomic account of the first-ever survey of freshwater Gastrotricha in Minas Gerais State. Samplings were carried out yielding six species of three Chaetonotidae genera: Aspidiophorus cf. pleustonicus, Ichthydium cf. chaetiferum, Chaetonotus acanthocephalus, Chaetonotus heideri, Chaetonotus cf. succinctus, Chaetonotus sp., and also an undescribed species belonging to the genus Redudasys (incertae sedis): this is the first finding of specimens of Redudasys outside of original type locality. These preliminary observations suggest that the knowledge of the biodiversity of Gastrotricha in the Minas Gerais State, as well as in the whole Brazil, will certainly increase as further investigations are undertaken, and that freshwater Macrodasyida may be more common than previously thought. PMID:21594197

  6. New data on freshwater psammic Gastrotricha from Brazil

    PubMed Central

    Garraffoni, André R. S.; Araujo, Thiago Q.; Lourenço, Anete P.; Balsamo, Maria

    2010-01-01

    Abstract Current knowledge of freshwater gastrotrich fauna from Brazil is underestimated as only two studies are available. The present communication is a taxonomic account of the first-ever survey of freshwater Gastrotricha in Minas Gerais State. Samplings were carried out yielding six species of three Chaetonotidae genera: Aspidiophorus cf. pleustonicus, Ichthydium cf. chaetiferum, Chaetonotus acanthocephalus, Chaetonotus heideri, Chaetonotus cf. succinctus, Chaetonotus sp., and also an undescribed species belonging to the genus Redudasys (incertae sedis): this is the first finding of specimens of Redudasys outside of original type locality. These preliminary observations suggest that the knowledge of the biodiversity of Gastrotricha in the Minas Gerais State, as well as in the whole Brazil, will certainly increase as further investigations are undertaken, and that freshwater Macrodasyida may be more common than previously thought. PMID:21594197

  7. Assessing and managing freshwater ecosystems vulnerable to global change

    USGS Publications Warehouse

    Angeler, David G.; Allen, Craig R.; Birge, Hannah E.; Drakare, Stina; McKie, Brendan G.; Johnson, Richard K.

    2014-01-01

    Freshwater ecosystems are important for global biodiversity and provide essential ecosystem services. There is consensus in the scientific literature that freshwater ecosystems are vulnerable to the impacts of environmental change, which may trigger irreversible regime shifts upon which biodiversity and ecosystem services may be lost. There are profound uncertainties regarding the management and assessment of the vulnerability of freshwater ecosystems to environmental change. Quantitative approaches are needed to reduce this uncertainty. We describe available statistical and modeling approaches along with case studies that demonstrate how resilience theory can be applied to aid decision-making in natural resources management. We highlight especially how long-term monitoring efforts combined with ecological theory can provide a novel nexus between ecological impact assessment and management, and the quantification of systemic vulnerability and thus the resilience of ecosystems to environmental change.

  8. Patterns of Freshwater Species Richness, Endemism, and Vulnerability in California.

    PubMed

    Howard, Jeanette K; Klausmeyer, Kirk R; Fesenmyer, Kurt A; Furnish, Joseph; Gardali, Thomas; Grantham, Ted; Katz, Jacob V E; Kupferberg, Sarah; McIntyre, Patrick; Moyle, Peter B; Ode, Peter R; Peek, Ryan; Quiñones, Rebecca M; Rehn, Andrew C; Santos, Nick; Schoenig, Steve; Serpa, Larry; Shedd, Jackson D; Slusark, Joe; Viers, Joshua H; Wright, Amber; Morrison, Scott A

    2015-01-01

    The ranges and abundances of species that depend on freshwater habitats are declining worldwide. Efforts to counteract those trends are often hampered by a lack of information about species distribution and conservation status and are often strongly biased toward a few well-studied groups. We identified the 3,906 vascular plants, macroinvertebrates, and vertebrates native to California, USA, that depend on fresh water for at least one stage of their life history. We evaluated the conservation status for these taxa using existing government and non-governmental organization assessments (e.g., endangered species act, NatureServe), created a spatial database of locality observations or distribution information from ~400 data sources, and mapped patterns of richness, endemism, and vulnerability. Although nearly half of all taxa with conservation status (n = 1,939) are vulnerable to extinction, only 114 (6%) of those vulnerable taxa have a legal mandate for protection in the form of formal inclusion on a state or federal endangered species list. Endemic taxa are at greater risk than non-endemics, with 90% of the 927 endemic taxa vulnerable to extinction. Records with spatial data were available for a total of 2,276 species (61%). The patterns of species richness differ depending on the taxonomic group analyzed, but are similar across taxonomic level. No particular taxonomic group represents an umbrella for all species, but hotspots of high richness for listed species cover 40% of the hotspots for all other species and 58% of the hotspots for vulnerable freshwater species. By mapping freshwater species hotspots we show locations that represent the top priority for conservation action in the state. This study identifies opportunities to fill gaps in the evaluation of conservation status for freshwater taxa in California, to address the lack of occurrence information for nearly 40% of freshwater taxa and nearly 40% of watersheds in the state, and to implement adequate

  9. Patterns of Freshwater Species Richness, Endemism, and Vulnerability in California

    PubMed Central

    Furnish, Joseph; Gardali, Thomas; Grantham, Ted; Katz, Jacob V. E.; Kupferberg, Sarah; McIntyre, Patrick; Moyle, Peter B.; Ode, Peter R.; Peek, Ryan; Quiñones, Rebecca M.; Rehn, Andrew C.; Santos, Nick; Schoenig, Steve; Serpa, Larry; Shedd, Jackson D.; Slusark, Joe; Viers, Joshua H.; Wright, Amber; Morrison, Scott A.

    2015-01-01

    The ranges and abundances of species that depend on freshwater habitats are declining worldwide. Efforts to counteract those trends are often hampered by a lack of information about species distribution and conservation status and are often strongly biased toward a few well-studied groups. We identified the 3,906 vascular plants, macroinvertebrates, and vertebrates native to California, USA, that depend on fresh water for at least one stage of their life history. We evaluated the conservation status for these taxa using existing government and non-governmental organization assessments (e.g., endangered species act, NatureServe), created a spatial database of locality observations or distribution information from ~400 data sources, and mapped patterns of richness, endemism, and vulnerability. Although nearly half of all taxa with conservation status (n = 1,939) are vulnerable to extinction, only 114 (6%) of those vulnerable taxa have a legal mandate for protection in the form of formal inclusion on a state or federal endangered species list. Endemic taxa are at greater risk than non-endemics, with 90% of the 927 endemic taxa vulnerable to extinction. Records with spatial data were available for a total of 2,276 species (61%). The patterns of species richness differ depending on the taxonomic group analyzed, but are similar across taxonomic level. No particular taxonomic group represents an umbrella for all species, but hotspots of high richness for listed species cover 40% of the hotspots for all other species and 58% of the hotspots for vulnerable freshwater species. By mapping freshwater species hotspots we show locations that represent the top priority for conservation action in the state. This study identifies opportunities to fill gaps in the evaluation of conservation status for freshwater taxa in California, to address the lack of occurrence information for nearly 40% of freshwater taxa and nearly 40% of watersheds in the state, and to implement adequate

  10. 2H and 18O Freshwater Isoscapes of Scotland

    NASA Astrophysics Data System (ADS)

    Meier-Augenstein, Wolfram; Hoogewerff, Jurian; Kemp, Helen; Frew, Danny

    2013-04-01

    Scotland's freshwater lochs and reservoirs provide a vital resource for sustaining biodiversity, agriculture, food production as well as for human consumption. Regular monitoring of freshwaters by the Scottish Environment Protection Agency (SEPA) fulfils legislative requirements with regards to water quality but new scientific methods involving stable isotope analysis present an opportunity combining these mandatory monitoring schemes with fundamental research to inform and deliver on current and nascent government policies [1] through gaining a greater understanding of Scottish waters and their importance in the context of climate change, environmental sustainability and food security. For example, 2H and 18O isoscapes of Scottish freshwater could be used to underpin research and its applications in: • Climate change - Using longitudinal changes in the characteristic isotope composition of freshwater lochs and reservoirs as proxy, isoscapes will provide a means to assess if and how changes in temperature and weather patterns might impact on precipitation patterns and amount. • Scottish branding - Location specific stable isotope signatures of Scottish freshwater have the potential to be used as a tool for provenancing and thus protecting premium Scottish produce such as Scottish beef, Scottish soft fruit and Scottish Whisky. During 2011 and 2012, with the support of SEPA more than 110 samples from freshwater lochs and reservoirs were collected from 127 different locations across Scotland including the Highlands and Islands. Here we present the results of this sampling and analysis exercise isotope analyses in form of 2H and 18O isoscapes with an unprecedented grid resolution of 26.5 × 26.5 km (or 16.4 × 16.4 miles). [1] Adaptation Framework - Adapting Our Ways: Managing Scotland's Climate Risk (2009): Scotland's Biodiversity: It's in Your Hands - A strategy for the conservation and enhancement of biodiversity in Scotland (2005); Recipe For Success - Scotland

  11. Prospective memory: A comparative perspective

    PubMed Central

    Crystal, Jonathon D.; Wilson, A. George

    2014-01-01

    Prospective memory consists of forming a representation of a future action, temporarily storing that representation in memory, and retrieving it at a future time point. Here we review the recent development of animal models of prospective memory. We review experiments using rats that focus on the development of time-based and event-based prospective memory. Next, we review a number of prospective-memory approaches that have been used with a variety of non-human primates. Finally, we review selected approaches from the human literature on prospective memory to identify targets for development of animal models of prospective memory. PMID:25101562

  12. Why freshwater organisms survived the asteroid that killed the dinosaurs

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2013-08-01

    Roughly 65.5 million years ago, a massive asteroid smashed into present-day Chicxulub, Mexico. The impact set fire to Earth's surface. Dust and ash darkened the sky, sending the planet into an "impact winter" that lasted months to years and caused the extinction of nonavian dinosaurs and half of ocean-dwelling species. However, life in inland freshwater ecosystems largely escaped this fate. To try to understand why freshwater organisms held on while ocean life failed, Robertson et al. surveyed relevant research to understand how the mechanisms of extinction would have operated differently in the two environments.

  13. Potential Impacts of Food Production on Freshwater Availability

    NASA Astrophysics Data System (ADS)

    Yano, Shinjiro; Hanasaki, Naota; Itsubo, Norihiro; Kim, Hyungjun; Oki, Taikan

    2014-05-01

    The sustainability of freshwater use is often evaluated based on the total volume of water consumption or withdrawal. However, the renewable freshwater resource and potential impacts of water depletion differ with location and water source. In addition, most estimates of the environmental impacts of water use have focused on depletion from a single-source perspective without separating geographically different water sources. Therefore, comprehensive potential impacts from multiple water sources remain unclear. In this study, we quantified the potential impacts of the global food production on freshwater availability (water availability footprint), applying the Water Availability Factor (fwa). Each water source including rainfall, surface water, and groundwater had individual fwa, which is calculated based on the geophysical hydrological cycle, to reflect the differences among renewable freshwater resources by place and source. The fwa for each water source was estimated based on land area or time period required to obtain the reference volume of freshwater. The reference volume was regarded as 1 m3 of rainfall over an area of 1.0 m2 (1,000 mm/year), based on the global mean annual precipitation. This concept is consistent with the Ecological Footprint (EF), which measures how much biologically productive land area is required to provide the resources consumed. The EF concept is measured in global hectares, a standardized unit equal to one hectare with global average bioproductivity. We found that the current agriculture consumes freshwater resources at 1.3 times the rapid rate than sustainable water use. This rate can also indicate environmental water scarcity. Among environmentally water-scarce countries, well-financed countries tend to import cereal products as virtual water to compensate for their domestic water resources. Among water-abundant countries, well-financed countries tend to export cereal products by exploiting their freshwater availability. The fwa

  14. RECOVERY OF FRESHWATER STORED IN SALINE AQUIFERS IN PENINSULAR FLORIDA.

    USGS Publications Warehouse

    Merritt, Michael L.

    1986-01-01

    Subsurface freshwater storage has been operationally tested at seven sites in central and south Florida. Injection was into a high chloride water aquifer at six sites, and into a high sulfate water aquifer at the seventh. Recovery efficiency has ranged from 0 to 75 percent in high chloride water aquifers, and has exceeded 100 percent in the high sulfate water aquifer. Computer modeling techniques were used to examine the geohydrologic, design, and management factors governing the recovery efficiency of subsurface freshwater storage. The modeling approach permitted many combinations of geohydrologic and operational conditions to be studied at relatively low cost.

  15. Biomarkers of Type II Synthetic Pyrethroid Pesticides in Freshwater Fish

    PubMed Central

    2014-01-01

    Type II synthetic pyrethroids contain an alpha-cyano group which renders them more neurotoxic than their noncyano type I counterparts. A wide array of biomarkers have been employed to delineate the toxic responses of freshwater fish to various type II synthetic pyrethroids. These include hematological, enzymatic, cytological, genetic, omic and other types of biomarkers. This review puts together the applications of different biomarkers in freshwater fish species in response to the toxicity of the major type II pyrethroid pesticides and assesses their present status, while speculating on the possible future directions. PMID:24868555

  16. Freshwater Variability between Ellesmere Island and the North Pole

    NASA Astrophysics Data System (ADS)

    Smethie, W. M.; Schlosser, P.; Newton, R.; Friedrich, R.; Steele, M.

    2013-12-01

    The Switchyard Project has established a time series of CTD and chemical measurements between Ellesmere Island and the North Pole and annual observations have been taken since 2005 to the present. The total freshwater inventory and inventories of the freshwater components (meteoric water [MEW], sea-ice melt water [SIMW] and inflow from the Pacific Ocean [PFW]) are determined from measurements of temperature, salinity, delta O-18, nitrate and phosphate, each year. The total inventory has varied by about 5 m between 2005 and 2013, which is about 50% of the lowest inventory. The total inventory was fairly stable between 2003 - 2007, then increased dramatically between 2007 and 2008 and again between 2008 and 2009. It then decreased between 2009 and 2011 and increased from 2011 to 2013. The increase between 2007 and 2008 resulted primarily from an increase in MEW tempered by decreases in SIMW and PFW. Back tracks of ice flow suggested that these waters came from the Russian continental shelves via the Transpolar Drift along the Lomonosov Ridge. The continued freshening in 2009 corresponded with a change is the large scale circulation of the Canada Basin with a weakening of the Beaufort Gyre and expulsion of freshwater, which included water from the large sea ice melting event of 2007. SIMW accounted for about two-thirds of the freshening. Ice back tracks suggest that water flowed out of the Beaufort Sea in an anticylonic pattern and crossed the Canada Basin along the Mendelev Ridge to reach the Lincoln Sea with a transport time of 2-3 years. The freshwater decrease between 2010 and 2011 was the result of a 70% decrease in SIMW and 30% decrease in MEW and the ice track flow pattern had shifted back to the pattern prior to 2009. The source of freshwater for the increase in freshwater inventory between 2011 and 2013 was MEW. PFW retreated to the continental shelf of Ellesmere Island, decreasing by about 30% and SIMW decreased to more negative values indicating water

  17. Assessing macroinvertebrate biodiversity in freshwater ecosystems: advances and challenges in DNA-based approaches

    EPA Science Inventory

    Assessing the biodiversity of macroinvertebrate faunas in freshwater ecosystems is an essential component of both basic ecological inquiry and applied ecological assessments. Aspects of taxonomic diversity and composition in freshwater communities are widely used to quantify wate...

  18. THE EFFECT OF FRESHWATER INFLOW ON NET ECOSYSTEM METABOLISM IN LAVACA BAY, TEXAS

    EPA Science Inventory

    Estuaries and other coastal ecosystems depend on freshwater inflow to maintain the gradients in environmental characteristics that define these transitional water bodies. Freshwater inflow (FWI) rates in many estuaries are changing due to changing land use patterns, water divers...

  19. 76 FR 17962 - Strengthening the Scientific Understanding of Climate Change Impacts on Freshwater Resources of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-31

    ... Geological Survey Strengthening the Scientific Understanding of Climate Change Impacts on Freshwater... titled ``Strengthening the Scientific Understanding of Climate Change Impacts on Freshwater Resources of... Federal Interagency Climate Change Adaptation Task Force and its Water Resources Workgroup....

  20. Incidence of the leech Actinobdella pediculata on freshwater drum in Lake Erie

    USGS Publications Warehouse

    Bur, Michael T.

    1994-01-01

    Actinobdella pediculata (Glossiphoniidae), a freshwater leech, was found attached to freshwater drum (Aplodinotus grunniens) from western Lake Erie during 1991 through 1993. The animal was first observed during routine examinations of freshwater drum collected in May 1991. The leeches were usually attached to the inside, lower portion of the opercula near the isthmus. Incidence of attachment increased with freshwater drum age and length. No noticeable adverse effects on the fish from attachment by the leech were noted.

  1. Physiological basis for large differences in resistance to nitrite among freshwater and freshwater-acclimated euryhaline fishes.

    PubMed

    Tomasso, Joseph R; Grosell, Martin

    2005-01-01

    Uptake of environmental NO2- by most freshwater fishes occurs at the gills where NO2- is actively transported into the blood by the Cl- uptake pathway. Some freshwater fishes do not concentrate NO2- in their plasma, regardless of environmental NO2- exposure and exhibit a high degree of resistance to NO2-. Recent studies indicate that freshwater-adapted killifish (Fundulidae: Fundulus heteroclitus) and European eel (Anguillidae: Anguilla anguilla) have no or minimal Cl- uptake activity at the gills relative to most freshwater fishes; rather, Cl- requirements are met in other ways (probably dietary). We hypothesized that different rates of Cl- uptake by the gill may explain the observed differences in NO2- uptake and consequent toxicity among freshwater fishes. Cl- influx rates of channel catfish (Ictaluridae: Ictalurus punctatus), a species that concentrates NO2- in the plasma and is sensitive to NO2-, and bluegill (Centrarchidae: Lepomis macrochirus), a species that does not concentrate NO2- in the plasma and is resistant to NO2-, were determined over a range of environmental Cl- concentrations. Channel catfish actively transported chloride into the plasma (Km = 155.6+/-101.2 micromol/L Cl-; Jmax = 414.9+/-51.4 nmol/g/h; +/-SEM). In contrast, bluegill exhibited no observable Cl- uptake. We placed our results and previously reported results in a phylogenetic context and concluded that differences in Cl- uptake mechanisms among groups of freshwater fishes may explain, in large part, the wide range of sensitivity to environmental NO2-. NO2- uptake determinations may also prove to be an easy screening method when studying the phylogenetic distribution and nature of Cl- uptake mechanisms in the gills of fishes. PMID:15667081

  2. "Key to Freshwater Algae": A Web-Based Tool to Enhance Understanding of Microscopic Biodiversity

    ERIC Educational Resources Information Center

    Shayler, Hannah A.; Siver, Peter A.

    2006-01-01

    The Freshwater Ecology Laboratory at Connecticut College has developed an interactive, Web-based identification key to freshwater algal genera using the Lucid Professional and Lucid 3 software developed by the Centre for Biological Information Technology at the University of Queensland, Brisbane, Australia. The "Key to Freshwater Algae" was funded…

  3. BIOREMEDIATION OF OIL-CONTAMINATED COASTAL FRESHWATER AND SALTWATER WETLANDS

    EPA Science Inventory

    Two field studies involving intentional releases of crude oil onto a freshwater wetland and a salt marsh were conducted in Canada in the summers of 1999 and 2000, respectively. The objective of both studies was to determine the role of nutrients in enhancing wetland restoration ...

  4. TOXICITY OF COPPER-SPIKED SEDIMENTS TO FRESHWATER INVERTEBRATES

    EPA Science Inventory

    Natural freshwater sediments from two Oregon sites were spiked with copper in the laboratory and two static toxicity tests were conducted with series of copper concentrations ranging from 59 to 10,600 mg/kg of dry sediment. Water (800 ml) was added to 1-liter test beakers over th...

  5. High diversity of magnetotactic deltaproteobacteria in a freshwater niche.

    PubMed

    Wang, Yinzhao; Lin, Wei; Li, Jinhua; Pan, Yongxin

    2013-04-01

    Knowledge of the diversity of magnetotactic bacteria in natural environments is crucial for understanding their contribution to various biological and geological processes. Here we report a high diversity of magnetotactic bacteria in a freshwater site. Ten out of 18 operational taxonomic units (OTUs) were affiliated with the Deltaproteobacteria. Some rod-shaped bacteria simultaneously synthesized greigite and magnetite magnetosomes. PMID:23377941

  6. High Diversity of Magnetotactic Deltaproteobacteria in a Freshwater Niche

    PubMed Central

    Wang, Yinzhao; Lin, Wei; Li, Jinhua

    2013-01-01

    Knowledge of the diversity of magnetotactic bacteria in natural environments is crucial for understanding their contribution to various biological and geological processes. Here we report a high diversity of magnetotactic bacteria in a freshwater site. Ten out of 18 operational taxonomic units (OTUs) were affiliated with the Deltaproteobacteria. Some rod-shaped bacteria simultaneously synthesized greigite and magnetite magnetosomes. PMID:23377941

  7. PHYSICOCHEMICAL FACTORS AFFECTING TOXICITY IN FRESHWATER: HARDNESS, PH, AND TEMPERATURE

    EPA Science Inventory

    A search of the literature for effects of hardness, pH, or temperature on the toxicity of chemicals to freshwater organisms suggested that the amount of reliable and useful data is limited. uch of the disparity among results reported in the literature was caused by improperly des...

  8. UV radiation and freshwater zooplankton: damage, protection and recovery

    PubMed Central

    Rautio, Milla; Tartarotti, Barbara

    2011-01-01

    While many laboratory and field studies show that zooplankton are negatively affected when exposed to high intensities of ultraviolet radiation (UVR), most studies also indicate that zooplankton are well adapted to cope with large variations in their UVR exposure in the pelagic zone of lakes. The response mechanisms of zooplankton are diverse and efficient and may explain the success and richness of freshwater zooplankton in optically variable waters. While no single behavioural or physiological protection mechanism seems to be superior, and while several unexplained and contradictory patterns exist in zooplankton UVR ecology, recent increases in our understanding are consistent with UVR playing an important role for zooplankton. This review examines the variability in freshwater zooplankton responses to UVR, with a focus on crustacean zooplankton (Cladocera and Copepoda). We present an overview of UVR-induced damages, and the protection and recovery mechanisms freshwater zooplankton use when exposed to UVR. We review the current knowledge of UVR impact on freshwater zooplankton at species and community levels, and discuss briefly how global change over the last three decades has influenced the UVR milieu in lakes. PMID:21516254

  9. Freshwater flocculation of suspended sediments in the Yangtze River, China

    NASA Astrophysics Data System (ADS)

    Guo, Leicheng; He, Qing

    2011-03-01

    This study focuses on suspended sediments and in situ flocculation in the Yangtze River, with the goal of improving our understanding of the relationship between freshwater and estuarine flocculation. A field survey with state-of-the-art instruments was carried out in January 2008 in the reach from downstream of the Three Gorges Dam to the estuary. The data show that in situ floc mean diameters range from 22 to 182 μm in the river, whereas the median dispersed grain sizes are 4.4-11.4 μm. This demonstrates that flocculation is an important process during the transport of suspended sediments along the river. The flocculation characteristics, suspended sediment concentration and dispersed grain sizes all vary longitudinally in the main stream of the Yangtze River. Biochemical factors are likely be more significant in the freshwater flocculation than in the estuary, where hydrodynamics and biochemical factors are both important. Flocculation is found in the freshwater river, in the estuary and in coastal waters, which indicates that dynamic break-up/reflocculation processes take place during the suspended sediment transport. The freshwater flocs may behave as parent flocs to the estuarine flocculation. This study enhances our understanding of flocculation from estuarine and coastal areas to fresh river systems and provides insights into the effects of input of riverine flocs to the estuarine flocculation and into the sources and fate of flocs.

  10. Escherichia coli and fecal coliforms in freshwater and estuarine sediments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It has been known for some time that substantial populations of fecal coliforms and E. coli are harbored in freshwater bottom sediments, bank soils, and beach sands. However, the relative importance of sediments as bacterial habitats and as a source of water-borne fecal coliforms and E. coli has not...

  11. Vectors of invasions in freshwater invertebrates and fishes

    USGS Publications Warehouse

    Fuller, Pam L.

    2015-01-01

    Without human assistance, the terrestrial environment and oceans represent barriers to the dispersal of freshwater aquatic organisms. The ability to overcome such barriers depends on the existence of anthropogenic vectors that can transport live organisms to new areas, and the species’ biology to survive the transportation and transplantation into the new environment (Johnson et al., 2006).

  12. Fatty acid amides from freshwater green alga Rhizoclonium hieroglyphicum.

    PubMed

    Dembitsky, V M; Shkrob, I; Rozentsvet, O A

    2000-08-01

    Freshwater green algae Rhizoclonium hieroglyphicum growing in the Ural Mountains were examined for their fatty acid amides using capillary gas chromatography-mass spectrometry (GC-MS). Eight fatty acid amides were identified by GC-MS. (Z)-9-octadecenamide was found to be the major component (2.26%). PMID:11014298

  13. Establishing a database of radionuclide transfer parameters for freshwater wildlife.

    PubMed

    Yankovich, T; Beresford, N A; Fesenko, S; Fesenko, J; Phaneuf, M; Dagher, E; Outola, I; Andersson, P; Thiessen, K; Ryan, J; Wood, M D; Bollhöfer, A; Barnett, C L; Copplestone, D

    2013-12-01

    Environmental assessments to evaluate potentials risks to humans and wildlife often involve modelling to predict contaminant exposure through key pathways. Such models require input of parameter values, including concentration ratios, to estimate contaminant concentrations in biota based on measurements or estimates of concentrations in environmental media, such as water. Due to the diversity of species and the range in physicochemical conditions in natural ecosystems, concentration ratios can vary by orders of magnitude, even within similar species. Therefore, to improve model input parameter values for application in aquatic systems, freshwater concentration ratios were collated or calculated from national grey literature, Russian language publications, and refereed papers. Collated data were then input into an international database that is being established by the International Atomic Energy Agency. The freshwater database enables entry of information for all radionuclides listed in ICRP (1983), in addition to the corresponding stable elements, and comprises a total of more than 16,500 concentration ratio (CRwo-water) values. Although data were available for all broad wildlife groups (with the exception of birds), data were sparse for many organism types. For example, zooplankton, crustaceans, insects and insect larvae, amphibians, and mammals, for which there were CRwo-water values for less than eight elements. Coverage was most comprehensive for fish, vascular plants, and molluscs. To our knowledge, the freshwater database that has now been established represents the most comprehensive set of CRwo-water values for freshwater species currently available for use in radiological environmental assessments. PMID:23103210

  14. A Guide to the Natural History of Freshwater Lake Bacteria†

    PubMed Central

    Newton, Ryan J.; Jones, Stuart E.; Eiler, Alexander; McMahon, Katherine D.; Bertilsson, Stefan

    2011-01-01

    Summary: Freshwater bacteria are at the hub of biogeochemical cycles and control water quality in lakes. Despite this, little is known about the identity and ecology of functionally significant lake bacteria. Molecular studies have identified many abundant lake bacteria, but there is a large variation in the taxonomic or phylogenetic breadths among the methods used for this exploration. Because of this, an inconsistent and overlapping naming structure has developed for freshwater bacteria, creating a significant obstacle to identifying coherent ecological traits among these groups. A discourse that unites the field is sorely needed. Here we present a new freshwater lake phylogeny constructed from all published 16S rRNA gene sequences from lake epilimnia and propose a unifying vocabulary to discuss freshwater taxa. With this new vocabulary in place, we review the current information on the ecology, ecophysiology, and distribution of lake bacteria and highlight newly identified phylotypes. In the second part of our review, we conduct meta-analyses on the compiled data, identifying distribution patterns for bacterial phylotypes among biomes and across environmental gradients in lakes. We conclude by emphasizing the role that this review can play in providing a coherent framework for future studies. PMID:21372319

  15. Comments on the Manuscript, "Biodiesel Production from Freshwater Algae"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recent publication (Vijayaragahavan, K.; Hemanathan, K., Biodiesel from freshwater algae, Energy Fuels, 2009, 23(11):5448-5453) on fuel production from algae is evaluated. It is discussed herein that the fuel discussed in that paper is not biodiesel, rather it probably consists of hydrocarbons. ...

  16. Field Study Manual to Freshwater and Estuarine Habitats.

    ERIC Educational Resources Information Center

    Georgia State Dept. of Education, Atlanta.

    This field studies manual, developed by biology students in the 1971 Georgia Governor's Honors Program, was designed for collection of data pertinent to freshwater and estuarine habitats. In addition to the various methods of sampling the ecosystem and for quantification of the data, instructions for dividing the field study into three logical…

  17. Freshwater Education: The Need, The Tools, and The "Vital Link."

    ERIC Educational Resources Information Center

    Shroeder, Linda

    1984-01-01

    Freshwater education programs are beginning to instill in young people a sense of awareness and a sense of responsibility regarding the future of water resources. Several of these programs are discussed, including Project COAST (Coastal, Oceanic, and Aquatic Studies) and "Acid Precipitation Learning Materials, Grades 7-12." (JN)

  18. Toxicity of rotenone to giant river freshwater prawn Macrobrachium rosenbergii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquaculturists have often suffered predation losses in the production of freshwater giant river prawn Macrobrachium rosenbergii due to the presence of wild fish species in culture ponds. The piscicide rotenone is widely used to remove undesirable fish species from ponds. Although evidence in the t...

  19. Effects of pollution on freshwater fish and amphibians

    SciTech Connect

    Pickering, Q.H.; Hunt, E.P.; Phipps, G.L.; Roush, T.H.; Smith, W.E.; Spehar, D.L.; Stephan, C.E.; Tanner, D.K.

    1983-06-01

    A literature review is presented dealing with studies on the effects of pollution on freshwater fish and amphibians. The pollutants studied included acid mine drainage, PCBs, cadmium, lead, naphthalene, plutonium, in addition to several studies dealing with pH effects. (JMT)

  20. FRESHWATER DECISION MAKERS' INFORMATION NEEDS: PHASE I REPORT

    EPA Science Inventory

    SERDP COLLECTION, SERDP (STRATEGIC ENVIRONMENTAL RESEARCH AND DEVELOPMENT PROGRAM) This project was launched as a follow up to the Freshwater imperative, which was initiated in 1990. The project was developed as a three-phase effort to identify priority research issues based on t...

  1. Freshwater Fish Assemblage Patterns in Rhode Island Streams and Rivers

    EPA Science Inventory

    Patterns in fish assemblages in streams and rivers can inform watershed and water management, yet these patterns are not well characterized for the U.S. state of Rhode Island. Here we relate freshwater fish data collected by the Rhode Island Department of Environmental Managemen...

  2. Viruses of freshwater finfish in the asian-pacific region.

    PubMed

    Sahoo, P K; Goodwin, A E

    2012-09-01

    There has been a tremendous increase in global demand for marine and freshwater fish to meet the protein needs of our expanding human population. However, due to the limited capacity of the wild-capture sector and a levelling of production from capture fisheries, the practice of farming aquatic animals has expanded rapidly to become a major global industry. Aquaculture, particularly freshwater aquaculture is now integral to the economies of many countries. A large number of aquatic animal species are farmed in high density in freshwater, brackish and marine systems, where they are exposed to new environments and potentially new diseases. Further, environmental stress factors, the use of manufactured feeds, and prolific global trade has led to the emergence and spread of new diseases. Viral pathogens, established for decades or newly emerging as disease threats, are particularly challenging since there are few efficacious treatments. Vaccines have been developed for some viral fish pathogens in salmonids, but vaccines are not available for many of the viral pathogens important in Asia. Control and eradication programs are difficult because many viral infections remain latent until adverse environmental conditions, such as overcrowding or poor water quality, trigger the onset of disease. Here, we review the more significant viral pathogens of finfish in the Asia-Pacific including both those with a long history in Asian aquaculture and emerging pathogens including betanodaviruses and koi herpes virus that have caused massive losses in the freshwater aquaculture and ornamental fish industries. PMID:23997433

  3. Specific primers for the detection of freshwater alphaproteobacterial magnetotactic cocci.

    PubMed

    Lin, Wei; Pan, Yongxin

    2009-12-01

    Freshwater magnetotactic cocci within Alphaproteobacteria are of ecological interest due to their ubiquitous distribution in aquatic environments as well as their potential roles in iron cycling and the bulk magnetism of sediment. To effectively investigate the diversity and distribution of these cocci, specific primers (FMTCf and FMTCr) were developed. Their specificity, applicability, and effectiveness were then evaluated theoretically and empirically. PMID:20112228

  4. Subsurface storage of freshwater in south Florida; a prospectus

    USGS Publications Warehouse

    Merritt, M.L.; Meyer, F.W.; Sonntag, W.H.; Fitzpatrick, D.J.

    1983-01-01

    A method of increasing storage capacity for freshwater in south Florida is to use brackish artesian aquifers as reservoirs. In this way, water deficiencies occurring during the annual dry season can be offset by surplus water obtained during the wet season and injected underground. Most of south Florida is underlain by several deep, confined, carbonate waterbearing zones which might be suitable for freshwater storage. These zones are in the Avon Park, Ocala, Suwannee, Tampa, and Hawthorn Formations. Experimental freshwater injection systems have been operated at five locations with promising, but not fully definitive, results. A determination of the feasibility of freshwater injection at a selected site begins with an assessment of the local geologic suitability. Verification of feasibility, however, requires injection and recovery tests to be performed at the site. Recovery efficiency, a measure of the success of the operation, is the amount of potable water, expressed as a percentage of the volume injected, which can be recovered before its salinity, or the concentration of other chemical constituents present in the native aquifer water, increases to the point that the recovered water is no longer useable. (USGS)

  5. BIOREMEDIATION OF OIL-CONTAMINATED COASTAL FRESHWATER AND SALTWATER WETLANDS

    EPA Science Inventory

    Two field studies involving intentional releases of crude oil onto a freshwater wetland and a salt marsh were conducted in Canada in the summers of 1999 and 2000, respectively. The objective of both studies was to determine the role of nutrients in enhancing wetland restoration i...

  6. Transitioning to Zero Freshwater Withdrawal for Thermoelectric Generation

    NASA Astrophysics Data System (ADS)

    Macknick, J.; Tidwell, V. C.; Zemlick, K. M.; Sanchez, J.; Woldeyesus, T.

    2013-12-01

    The electricity sector is the largest withdrawer of freshwater in the United States. The primary demand for water from the electricity sector is for cooling thermoelectric power plants. Droughts and potential changes in water resources resulting from climate change pose important risks to thermoelectric power production in the United States. Power plants can minimize risk in a variety of ways. One method of reducing risk is to move away from dependency on freshwater resources. Here a scoping level analysis is performed to identify the technical tradeoffs and initial cost estimates for retrofitting all existing steam-powered generation to achieve zero freshwater withdrawal. Specifically, the conversion of existing freshwater-cooled plants to dry cooling or a wet cooling system utilizing non-potable water is considered. The least cost alternative is determined for each of the 1,178 freshwater using power plants in the United States. The use of non-potable water resources, such as municipal wastewater and shallow brackish groundwater, is considered based on the availability and proximity of those resources to the power plant, as well as the costs to transport and treat those resources to an acceptable level. The projected increase in levelized cost of electricity due to power plant retrofits ranges roughly from 0.20 to 20/MWh with a median value of 3.53/MWh. With a wholesale price of electricity running about 35/MWh, many retrofits could be accomplished at levels that would add less than 10% to current power plant generation expenses. Such retrofits could alleviate power plant vulnerabilities to thermal discharge limits in times of drought (particularly in the East) and would save 3.2 Mm3/d of freshwater consumption in watersheds with limited water availability (principally in the West). The estimated impact of retrofits on wastewater and brackish water supply is minimal requiring only a fraction of the available resource. Total parasitic energy requirements to

  7. Selecting Reliable and Robust Freshwater Macroalgae for Biomass Applications

    PubMed Central

    Lawton, Rebecca J.; de Nys, Rocky; Paul, Nicholas A.

    2013-01-01

    Intensive cultivation of freshwater macroalgae is likely to increase with the development of an algal biofuels industry and algal bioremediation. However, target freshwater macroalgae species suitable for large-scale intensive cultivation have not yet been identified. Therefore, as a first step to identifying target species, we compared the productivity, growth and biochemical composition of three species representative of key freshwater macroalgae genera across a range of cultivation conditions. We then selected a primary target species and assessed its competitive ability against other species over a range of stocking densities. Oedogonium had the highest productivity (8.0 g ash free dry weight m−2 day−1), lowest ash content (3–8%), lowest water content (fresh weigh: dry weight ratio of 3.4), highest carbon content (45%) and highest bioenergy potential (higher heating value 20 MJ/kg) compared to Cladophora and Spirogyra. The higher productivity of Oedogonium relative to Cladophora and Spirogyra was consistent when algae were cultured with and without the addition of CO2 across three aeration treatments. Therefore, Oedogonium was selected as our primary target species. The competitive ability of Oedogonium was assessed by growing it in bi-cultures and polycultures with Cladophora and Spirogyra over a range of stocking densities. Cultures were initially stocked with equal proportions of each species, but after three weeks of growth the proportion of Oedogonium had increased to at least 96% (±7 S.E.) in Oedogonium-Spirogyra bi-cultures, 86% (±16 S.E.) in Oedogonium-Cladophora bi-cultures and 82% (±18 S.E.) in polycultures. The high productivity, bioenergy potential and competitive dominance of Oedogonium make this species an ideal freshwater macroalgal target for large-scale production and a valuable biomass source for bioenergy applications. These results demonstrate that freshwater macroalgae are thus far an under-utilised feedstock with much potential

  8. Comparison of the respiratory metabolism of juvenile Litopenaeus vannamei cultured in seawater and freshwater

    NASA Astrophysics Data System (ADS)

    Ding, Sen; Wang, Fang; Dong, Shuanglin; Li, Ying

    2013-11-01

    Litopenaeus vannamei, a euryhaline species, can be cultured at a wide range of salinities. The emergence of freshwater pond-culture of L. vannamei is an important prelude to the continued development of shrimp culture in China. In this study, we compared the respiratory metabolism of juvenile L. vannamei cultured in freshwater and saltwater by measuring their oxygen consumption rate (OCR), ammonium-type nitrogen excretion rate (AER) and pyruvate kinase (PK) and lactate dehydrogenase (LDH) activities at different molting stages in order to physiecologically characterize juvenile L. vannamei under freshwater conditions. The results showed that OCR was significantly higher in saltwater than in freshwater at all stages of molting cycle. However, variation of OCR among molting stages in saltwater was similar with that in freshwater, and the highest OCR was observed at post-molting stage. At all stages of molting cycle, AER was significantly higher in freshwater than in saltwater, and the highest was observed at post-molting stage. The activity of PK was significantly higher in saltwater than in freshwater. Conversely, the activity of LDH was higher in freshwater than in saltwater in general. Significant variation of PK and LDH activities in molting cycle was observed in saltwater and freshwater. The results indicated that aerobic metabolism of juvenile L. vannamei was more active in saltwater than in freshwater; while its protein metabolism was more active in freshwater than in saltwater.

  9. Estimation of Freshwater Flow to Joe Bay, South Florida.

    NASA Astrophysics Data System (ADS)

    Zucker, M. A.; Hittle, C. D.

    2002-05-01

    During the last century, drainage canals were constructed as part of the Central and Southern Flood Control (C&SF) project. Flood control was achieved but degradation to the Everglades ecosystem was evident. Problems related to Florida Bay include sea grass die off, algae blooms, and extreme salinity conditions. Modifications to the C&SF project are proposed as part of the Comprehensive Everglades Restoration Plan (CERP). One objective of CERP is to improve the timing and distribution of freshwater flow within the Everglades ecosystem and to Florida Bay. Several CERP projects propose changes to the existing canal network that borders Everglades National Park (ENP) in southern Miami-Dade County. An examination of flows to Joe Bay, a small embayment on the northeastern shores of Florida Bay, has provided baseline information on current spatial and temporal water deliveries prior to CERP modifications. Understanding the existing complex water delivery system and the effects the system has on Everglades hydrology will provide a necessary benchmark against which to measure restoration success. The study was initiated by the U.S. Geological Survey (USGS) in May 1999 to estimate creek flows to Joe Bay and determine the relative amounts derived from Taylor Slough and overflow from the C-111 Canal. It is important to understand the source of freshwater to Joe Bay before it enters Florida Bay. Taylor Slough transports freshwater to northeastern Florida Bay from the northwest while overflow from the C-111 Canal provides freshwater to northeastern Florida Bay from the northeast. Joe Bay, receives part of the freshwater from each of these sources via sheet flow and small estuarine creeks, and subsequently discharges southward to northeastern Florida Bay via Trout Creek. Trout Creek contributes approximately 50 percent of the total freshwater flow to northeastern Florida Bay (Hittle 2001). Eight non-gaged creeks entering Joe Bay were selected for acoustic Doppler current

  10. Swimming in the USA: beachgoer characteristics and health outcomes at US marine and freshwater beaches

    PubMed Central

    Collier, Sarah A.; Wade, Timothy J.; Sams, Elizabeth A.; Hlavsa, Michele C.; Dufour, Alfred P.; Beach, Michael J.

    2015-01-01

    Swimming in lakes and oceans is popular, but little is known about the demographic characteristics, behaviors, and health risks of beachgoers on a national level. Data from a prospective cohort study of beachgoers at multiple marine and freshwater beaches in the USA were used to describe beachgoer characteristics and health outcomes for swimmers and non-swimmers. This analysis included 54,250 participants. Most (73.2%) entered the water; of those, 65.1% put their head under water, 41.3% got water in their mouth and 18.5% swallowed water. Overall, 16.3% of beachgoers reported any new health problem. Among swimmers, 6.6% reported gastrointestinal (GI) illness compared with 5.5% of non-swimmers (unadjusted χ2 p < 0.001); 6.0% of swimmers and 4.9% of non-swimmers reported respiratory illness (p < 0.001); 1.8% of swimmers and 1.0% of non-swimmers reported ear problems (p < 0.001); and 3.9% of swimmers and 2.4% of non-swimmers experienced a rash (p < 0.001). Overall, swimmers reported a higher unadjusted incidence of GI illness and earaches than non-swimmers. Current surveillance systems might not detect individual cases and outbreaks of illness associated with swimming in natural water. Better knowledge of beachgoer characteristics, activities, and health risks associated with swimming in natural water can improve disease surveillance and prioritize limited resources. PMID:26042984

  11. The potential of freshwater macroalgae as a biofuels feedstock and the influence of nutrient availability on freshwater macroalgal biomass production

    NASA Astrophysics Data System (ADS)

    Yun, Jin-Ho

    Extensive efforts have been made to evaluate the potential of microalgae as a biofuel feedstock during the past 4-5 decades. However, filamentous freshwater macroalgae have numerous characteristics that favor their potential use as an alternative algal feedstock for biofuels production. Freshwater macroalgae exhibit high rates of areal productivity, and their tendency to form dense floating mats on the water surface imply significant reductions in harvesting and dewater costs compared to microalgae. In Chapter 1, I reviewed the published literature on the elemental composition and energy content of five genera of freshwater macroalgae. This review suggested that freshwater macroalgae compare favorably with traditional bio-based energy sources, including terrestrial residues, wood, and coal. In addition, I performed a semi-continuous culture experiment using the common Chlorophyte genus Oedogonium to investigate whether nutrient availability can influence its higher heating value (HHV), productivity, and proximate analysis. The experimental study suggested that the most nutrient-limited growth conditions resulted in a significant increase in the HHV of the Oedogonium biomass (14.4 MJ/kg to 16.1 MJ/kg). Although there was no significant difference in productivity between the treatments, the average dry weight productivity of Oedogonium (3.37 g/m2/day) was found to be much higher than is achievable with common terrestrial plant crops. Although filamentous freshwater macroalgae, therefore, have significant potential as a renewable source of bioenergy, the ultimate success of freshwater macroalgae as a biofuel feedstock will depend upon the ability to produce biomass at the commercial-scale in a cost-effective and sustainable manner. Aquatic ecology can play an important role to achieve the scale-up of algal crop production by informing the supply rates of nutrients to the cultivation systems, and by helping to create adaptive production systems that are resilient to

  12. Early warning of freshwater salinization due to upward brine displacement by species transport simulations combined with a hydrochemical genesis model

    NASA Astrophysics Data System (ADS)

    Langer, Maria; Kühn, Michael

    2016-04-01

    Shallow groundwater resources could be possibly affected by intruding brines, which are displaced along hydraulically conductive faults as result of subsurface activities like CO2 injection. To avoid salinization of potable freshwater aquifers an early detection of intruding saline water is necessary, especially in regions where an initial geogenic salinization already exists. Our study is based on work of Tillner et al. [1] and Langer et al. [2] who investigated the influence of permeable fault systems on brine displacement for the prospective storage site Beeskow-Birkholz in the Northeast German Basin. With a 3D regional scale model considering the deep groundwater system, they demonstrated that the existence of hydraulically conductive faults is not necessarily an exclusion criterion for potential injection sites, because salinization of shallower aquifers strongly depends on the effective damage zone volume, the initial salinity distribution and overlying reservoirs [2], while permeability of fault zones does not influence salinization of shallower aquifers significantly [1]. Here we extracted a 2D cross section regarding the upper 220 m of the study area mainly represented by shallow freshwater aquifers, but also considering an initial geogenic salinization [3]. We took flow rates of the intruding brines from the previous studies [2] and implemented species transport simulations with the program code SHEMAT [4]. Results are investigated and interpreted with the hydrochemical genesis model GEBAH [5] which has been already applied as early warning of saltwater intrusions into freshwater aquifers and surface water [6]. GEBAH allows a categorization of groundwater by the ion ratios of the dissolved components and offers a first indicative determination for an existence and the intensity of saline water intrusion in shallow groundwater aquifer, independent of the concentration of the solution. With our model we investigated the migration of saline water through a

  13. Food of freshwater drum in western Lake Erie

    USGS Publications Warehouse

    Bur, Michael T.

    1982-01-01

    The abundance of freshwater drum (Aplodinotus grunniens) suggests they play an important role in the Lake Erie ecosystem. Our analysis of freshwater drum digestive tracts and macrobenthic samples collected from western Lake Erie indicates that drum were selective feeders. Planktonic cladocerans and larval midges (Chironomidae) were the primary prey organisms eaten by drum. Young-of-the-year fed mostly on cladocerans, while yearling and older drum ate both cladocerans and midge larvae. Decapods, pelecypods, and fish were found only in the digestive tracts of drum longer than 250 mm. While the most abundant organisms in benthic samples were cladocerans (ephippial) and oligochaetes (89.5% by number), they constituted less than 1% of the diet. An evaluation of food selectivity, using Ivlev's index of electivity for benthic organisms, indicated that adult drum preferred midges to any other benthic food.

  14. The gastrointestinal phage communities of the cultivated freshwater fishes.

    PubMed

    He, Yang; Yang, Hongjiang

    2015-03-01

    The phage communities in the gut of 62 cultivated freshwater fish were investigated by culture-based methods. Using three selective media, 445 pathogenic bacilli strains were isolated and used as indicators for subsequent phage isolations. Totally, 63 phages were detected and the respective host strains were identified with the comparative sequence analysis of 16S rRNA gene, including Aeromonas (29), Vibrio (1), Citrobacter (16), Serratia (4), Enterobacter (2), Proteus (3), Buttiauxella (2), Plesiomonas (2), Kluyvera (1), Morgenella (2) and Providencia (1). The diversity of Aeromonas phages was assessed by discrimination of their host strains with random amplified polymorphic DNA method. Furthermore, the isolated Aeromonas phages were characterized by host range and growth inhibition assay. The results demonstrated that there were abundant and diverse phage populations in the gut environment of the cultivated freshwater fishes. The phages could contribute to the microbiota balance in the gut ecosystem of fishes and provide reliable phage sources for future applications. PMID:25743067

  15. Combined ecological risks of nitrogen and phosphorus in European freshwaters.

    PubMed

    Azevedo, Ligia B; van Zelm, Rosalie; Leuven, Rob S E W; Hendriks, A Jan; Huijbregts, Mark A J

    2015-05-01

    Eutrophication is a key water quality issue triggered by increasing nitrogen (N) and phosphorus (P) levels and potentially posing risks to freshwater biota. We predicted the probability that an invertebrate species within a community assemblage becomes absent due to nutrient stress as the ecological risk (ER) for European lakes and streams subjected to N and P pollution from 1985 to 2011. The ER was calculated as a function of species-specific tolerances to NO3(-) and total P concentrations and water quality monitoring data. Lake and stream ER averaged 50% in the last monitored year (i.e. 2011) and we observed a decrease by 22% and 38% in lake and stream ER (respectively) of river basins since 1985. Additionally, the ER from N stress surpassed that of P in both freshwater systems. The ER can be applied to identify river basins most subjected to eutrophication risks and the main drivers of impacts. PMID:25700335

  16. Freshwater ecosystems and aquatic insects: a paradox in biological invasions.

    PubMed

    Fenoglio, Stefano; Bonada, Núria; Guareschi, Simone; López-Rodríguez, Manuel J; Millán, Andrés; Tierno de Figueroa, J Manuel

    2016-04-01

    Biological invasions have increased significantly in response to global change and constitute one of the major causes of biodiversity loss. Insects make up a large fraction of invasive species, in general, and freshwaters are among the most invaded ecosystems on our planet. However, even though aquatic insects dominate most inland waters, have unparalleled taxonomic diversity and occupy nearly all trophic niches, there are almost no invasive insects in freshwaters. We present some hypotheses regarding why aquatic insects are not common among aquatic invasive organisms, suggesting that it may be the result of a suite of biological, ecological and anthropogenic factors. Such specific knowledge introduces a paradox in the current scientific discussion on invasive species; therefore, a more in-depth understanding could be an invaluable aid to disentangling how and why biological invasions occur. PMID:27072403

  17. Identification of Major Planktonic Sulfur Oxidizers in Stratified Freshwater Lake

    PubMed Central

    Kojima, Hisaya; Watanabe, Tomohiro; Iwata, Tomoya; Fukui, Manabu

    2014-01-01

    Planktonic sulfur oxidizers are important constituents of ecosystems in stratified water bodies, and contribute to sulfide detoxification. In contrast to marine environments, taxonomic identities of major planktonic sulfur oxidizers in freshwater lakes still remain largely unknown. Bacterioplankton community structure was analyzed in a stratified freshwater lake, Lake Mizugaki in Japan. In the clone libraries of 16S rRNA gene, clones very closely related to a sulfur oxidizer isolated from this lake, Sulfuritalea hydrogenivorans, were detected in deep anoxic water, and occupied up to 12.5% in each library of different water depth. Assemblages of planktonic sulfur oxidizers were specifically analyzed by constructing clone libraries of genes involved in sulfur oxidation, aprA, dsrA, soxB and sqr. In the libraries, clones related to betaproteobacteria were detected with high frequencies, including the close relatives of Sulfuritalea hydrogenivorans. PMID:24695535

  18. Occupational health issues in marine and freshwater research

    PubMed Central

    2012-01-01

    Marine and freshwater scientists are potentially exposed to a wide variety of occupational hazards. Depending on the focus of their research, risks may include animal attacks, physiological stresses, exposure to toxins and carcinogens, and dangerous environmental conditions. Many of these hazards have been investigated amongst the general population in their recreational use of the environment; however, very few studies have specifically related potential hazards to occupational exposure. For example, while the incidence of shark and crocodile attacks may invoke strong emotions and the occupational risk of working with these animals is certainly real, many more people are stung by jellyfish or bitten by snakes or dogs each year. Furthermore, a large proportion of SCUBA-related injuries and deaths are incurred by novice or uncertified divers, rather than professional divers using aquatic environments. Nonetheless, marine and freshwater research remains a potentially risky occupation, and the likelihood of death, injury and long-term health impacts still needs to be seriously considered. PMID:22429712

  19. Halophytophthora fluviatilis sp. nov. from freshwater in Virginia.

    PubMed

    Yang, Xiao; Hong, Chuanxue

    2014-03-01

    Halophytophthora fluviatilis, a novel species from inland freshwater in Virginia, is characterized and described in this study. This homothallic species produced ovoid to globose sporangia, which release zoospores directly through exit pores. It grew well in a relatively wide range of salinity from 1.8 to 19.0 parts per thousand. Sequence analysis of the rRNA internal transcribed spacer region placed this new species in the Halophytophthora sensu stricto clade. Description of this new species expanded the habitat to include geographically distinct inland freshwater ecosystems for the genus Halophytophthora, challenging the notion that this genus is marine or brackish. The need to construct a molecular-based taxonomy for the genus Halophytophthora is also discussed. PMID:24484074

  20. Influence of net freshwater supply on salinity in Florida Bay

    USGS Publications Warehouse

    Nuttle, W.K.; Fourqurean, J.W.; Cosby, B.J.; Zieman, J.C.; Robblee, M.B.

    2000-01-01

    An annual water budget for Florida Bay, the large, seasonally hypersaline estuary in the Everglades National Park, was constructed using physically based models and long-term (31 years) data on salinity, hydrology, and climate. Effects of seasonal and interannual variations of the net freshwater supply (runoff plus rainfall minus evaporation) on salinity variation within the bay were also examined. Particular attention was paid to the effects of runoff, which are the focus of ambitious plans to restore and conserve the Florida Bay ecosystem. From 1965 to 1995 the annual runoff from the Everglades into the bay was less than one tenth of the annual direct rainfall onto the bay, while estimated annual evaporation slightly exceeded annual rainfall. The average net freshwater supply to the bay over a year was thus approximately zero, and interannual variations in salinity appeared to be affected primarily by interannual fluctuations in rainfall. At the annual scale, runoff apparently had little effect on the bay as a whole during this period. On a seasonal basis, variations in rainfall, evaporation, and runoff were not in phase, and the net freshwater supply to the bay varied between positive and negative values, contributing to a strong seasonal pattern in salinity, especially in regions of the bay relatively isolated from exchanges with the Gulf of Mexico and Atlantic Ocean. Changes in runoff could have a greater effect on salinity in the bay if the seasonal patterns of rainfall and evaporation and the timing of the runoff are considered. One model was also used to simulate spatial and temporal patterns of salinity responses expected to result from changes in net freshwater supply. Simulations in which runoff was increased by a factor of 2 (but with no change in spatial pattern) indicated that increased runoff will lower salinity values in eastern Florida Bay, increase the variability of salinity in the South Region, but have little effect on salinity in the Central

  1. Widespread distribution of ability to oxidize manganese among freshwater bacteria.

    PubMed

    Gregory, E; Staley, J T

    1982-08-01

    Manganese-oxidizing heterotrophic bacteria were found to comprise a significant proportion of the bacterial community of Lake Washington (Seattle, Wash.) and Lake Virginia (Winter Park, Fla.). Identification of these freshwater bacteria showed that members of a variety of genera are capable of oxidizing manganese. Isolates maintained in the laboratory spontaneously lost the ability to oxidize manganese. A direct correlation was found between the presence of plasmid DNA and the ability of the organism to oxidize manganese. PMID:16346084

  2. Occurrence of microcystin-producing cyanobacteria in Ugandan freshwater habitats

    PubMed Central

    Okello, William; Portmann, Cyril; Erhard, Marcel; Gademann, Karl; Kurmayer, Rainer

    2011-01-01

    Microcystins (MCs) are cyclic heptapeptides that are the most abundant toxins produced by cyanobacteria in freshwater. The phytoplankton of many freshwater lakes in Eastern Africa is dominated by cyanobacteria. Less is known, however, on the occurrence of MC producers and the production of MCs. Twelve Ugandan freshwater habitats ranging from mesotrophic to hypertrophic conditions were sampled in May and June of 2004 and April of 2008 and were analyzed for their physico-chemical parameters, phytoplankton composition, and MC concentrations. Among the group of the potential MC-producing cyanobacteria, Anabaena (0 - 107 cells ml−1) and Microcystis (103 - 107 cells ml−1) occurred most frequently and dominated in eutrophic systems. A significant linear relationship (n = 31, r2 = 0.38, p < 0.001) between the Microcystis cell numbers and MC concentration (1.3-93 fg of MC cell−1) was observed. Beside [MeAsp3, Mdha7]-MC-RR two new microcystins, [Asp3]-MC-RY and [MeAsp3]-MC-RY were isolated and their constitution assigned by LC-MS2. In order to identify the MC-producing organism in the water samples (i), the conserved aminotransferase domain part of the mcyE gene that is indicative of MC production was amplified by general primers and cloned and sequenced, and (ii), genus-specific primers were used to amplify the mcyE gene of the genera Microcystis, Anabaena, and Planktothrix. Only mcyE genotypes that are indicative of Microcystis sp. were obtained via the environmental cloning approach (337 bp, 96.1%-96.7% similarity to the Microcystis aeruginosa strain PCC7806). Accordingly, only the mcyE primers, which are specific for Microcystis, revealed PCR products. We concluded that Microcystis is the major MC-producer in Ugandan freshwater. PMID:19609871

  3. Serum antileptospiral agglutinins in freshwater turtles from Southern Brazil

    PubMed Central

    Silva, Éverton F; Seyffert, Núbia; Cerqueira, Gustavo M.; Leihs, Karl P.; Athanazio, Daniel A.; Valente, Ana L. S.; Dellagostin, Odir A.; Brod, Claudiomar S.

    2009-01-01

    In this study, we observed the presence of antileptospiral agglutinins in freshwater turtles of two urban lakes of Pelotas, Southern Brazil. Forty animals (29 Trachemys dorbigny and 11 Phrynops hilarii) were captured and studied. Attempts to isolate leptospires from blood and urine samples were unsuccessful. Serum samples (titer > 100) reactive to pathogenic strains were observed in 11 animals. These data encourage surveys of pet turtles to evaluate the risk of transmission of pathogenic leptospires to humans. PMID:24031348

  4. Laboratory Experiment of Saltwater Intrusion into Freshwater Aquifer

    NASA Astrophysics Data System (ADS)

    Maekawa, K.; Karasaki, K.; Takasu, T.

    2006-12-01

    It is important for safety assessment of high-level radioactive waste geologic disposal to understand groundwater flow in deep underground accurately. Especially groundwater flow in the coastal area considered to be quite complex that involves density and hydraulic gradient driven flow of freshwater and saltwater. Furthermore, bentonite, which is one of the favored artificial barrier materials, may not swell very well in saltwater as it does in freshwater, and therefore may not provide a reliable seal if salinity is high enough. In order to understand the behavior of saltwater intrusion into freshwater in deep underground, we constructed a laboratory equipment "Mini-MACRO" named after the original large scale MACRO (MAss transport Characterization in host ROck) and aimed to increase a precision and efficiency of experiment. Mini-MACRO equipment consists of three parts: a sandbox (0.5m x 0.25m x 0.1m) and each reservoir tank for saltwater and freshwater. Saltwater intrusion experiments are conducted using glass beads (sub-millimeter in diameter) and colored saltwater in the sandbox with a transparent face plate to allow visual observation. In the present paper we summarize the concept of the equipment design and the results of the experiment that we created several cases of experimental conditions to observe the saltwater intrusion behavior against various hydraulic gradients and densities of saltwater. This equipment contributes to the better understanding of saltwater intrusion behavior and to increasing confidence in modeling methodology of groundwater flow and mass transport in deep underground through comparison with numerical analysis. We believe that it is crucial for the safety assessment of geologic disposal to integrate this knowledge.

  5. Factors controlling bacterial production in marine and freshwater sediments.

    PubMed

    Sander, B C; Kalff, J

    1993-09-01

    We collected benthic bacterial production data measured by (3)H thymidine incorporation (TTI) (25 studies), frequency of dividing cells (FDC) (3 studies), dark-C02 assimilation (1 study) and (3)H-adenine uptake (2 studies) from the literature, which included 18 marine, 6 river, and 2 lake studies. In all of the studies that used the TTI method, (3)H-DNA was isolated and incubations were carried out at in situ temperatures. Most of the researchers also determined (3)H-DNA extraction efficiencies and isotope dilution, thus interpretable estimates of bacterial production were used in the analysis. In marine sediments, bacterial production rates were linked to bacterial biomass, bacterial abundance, sediment organic matter, temperature, and sediment chlorophyll a, with these variables explaining between 40% and 68% of the variation in production rates. Simple relationships between production and bacterial biomass or bacterial abundance, or between production and sediment organic matter, were improved by also including temperature in the analysis of marine sediments. Sediment organic matter explained an appreciable fraction (58%) of the observed production in freshwater sediments. Temperature was the most powerful predictor of the observed variability in specific growth rates (r (2) = 0.48 and r (2) = 0.58) in marine and freshwater sediments, respectively. Thus, bacterial production and specific growth rates are most closely linked to substrate supply and temperature in marine and freshwater sediments. PMID:24190006

  6. Assimilation impacts on Arctic Ocean circulation, heat and freshwater budgets

    NASA Astrophysics Data System (ADS)

    Zuo, Hao; Mugford, Ruth I.; Haines, Keith; Smith, Gregory C.

    We investigate the Arctic basin circulation, freshwater content (FWC) and heat budget by using a high-resolution global coupled ice-ocean model implemented with a state-of-the-art data assimilation scheme. We demonstrate that, despite a very sparse dataset, by assimilating hydrographic data in and near the Arctic basin, the initial warm bias and drift in the control run is successfully corrected, reproducing a much more realistic vertical and horizontal structure to the cyclonic boundary current carrying the Atlantic Water (AW) along the Siberian shelves in the reanalysis run. The Beaufort Gyre structure and FWC and variability are also more accurately reproduced. Small but important changes in the strait exchange flows are found which lead to more balanced budgets in the reanalysis run. Assimilation fluxes dominate the basin budgets over the first 10 years (P1: 1987-1996) of the reanalysis for both heat and FWC, after which the drifting Arctic upper water properties have been restored to realistic values. For the later period (P2: 1997-2004), the Arctic heat budget is almost balanced without assimilation contributions, while the freshwater budget shows reduced assimilation contributions compensating largely for surface salinity damping, which was extremely strong in this run. A downward trend in freshwater export at the Canadian Straits and Fram Strait is found in period P2, associated with Beaufort Gyre recharge. A detailed comparison with observations and previous model studies at the individual Arctic straits is also included.

  7. A synthetic phylogeny of freshwater crayfish: insights for conservation.

    PubMed

    Owen, Christopher L; Bracken-Grissom, Heather; Stern, David; Crandall, Keith A

    2015-02-19

    Phylogenetic systematics is heading for a renaissance where we shift from considering our phylogenetic estimates as a static image in a published paper and taxonomies as a hardcopy checklist to treating both the phylogenetic estimate and dynamic taxonomies as metadata for further analyses. The Open Tree of Life project (opentreeoflife.org) is developing synthesis tools for harnessing the power of phylogenetic inference and robust taxonomy to develop a synthetic tree of life. We capitalize on this approach to estimate a synthesis tree for the freshwater crayfish. The crayfish make an exceptional group to demonstrate the utility of the synthesis approach, as there recently have been a number of phylogenetic studies on the crayfishes along with a robust underlying taxonomic framework. Importantly, the crayfish have also been extensively assessed by an IUCN Red List team and therefore have accurate and up-to-date area and conservation status data available for analysis within a phylogenetic context. Here, we develop a synthesis phylogeny for the world's freshwater crayfish and examine the phylogenetic distribution of threat. We also estimate a molecular phylogeny based on all available GenBank crayfish sequences and use this tree to estimate divergence times and test for divergence rate variation. Finally, we conduct EDGE and HEDGE analyses and identify a number of species of freshwater crayfish of highest priority in conservation efforts. PMID:25561670

  8. South China Sea throughflow: A heat and freshwater conveyer belt

    NASA Astrophysics Data System (ADS)

    Qu, T.; Du, Y.

    2006-12-01

    Water of the Pacific origin enters the South China Sea through Luzon Strait. From there it flows southward into the Java Sea through Karimata Strait. Part of the water returns to the Pacific through Makassar Strait, while the rest leaks into the Indian Ocean through Indonesian archipelago. Analysis of surface flux data suggests that this circulation, termed the South China Sea throughflow, acts as a heat and freshwater conveyer belt transferring up to 0.2 PW of heat and 0.1 Sv of freshwater from the South China Sea to the Maritime Continent. As both surface heat and freshwater fluxes display substantially different temporal variabilities with the South China Sea throughflow, we hypothesize that the upper South China Sea is a buffer receiving an excess of heat in certain years and releasing it in others. Results from a high-resolution general circulation model confirm this hypothesis, implying that the South China Sea is likely to play a more active role than previously thought in regulating the sea surface temperature pattern in the Maritime Continent and its adjoining western Pacific and eastern Indian Oceans.

  9. A synthetic phylogeny of freshwater crayfish: insights for conservation

    PubMed Central

    Owen, Christopher L.; Bracken-Grissom, Heather; Stern, David; Crandall, Keith A.

    2015-01-01

    Phylogenetic systematics is heading for a renaissance where we shift from considering our phylogenetic estimates as a static image in a published paper and taxonomies as a hardcopy checklist to treating both the phylogenetic estimate and dynamic taxonomies as metadata for further analyses. The Open Tree of Life project (opentreeoflife.org) is developing synthesis tools for harnessing the power of phylogenetic inference and robust taxonomy to develop a synthetic tree of life. We capitalize on this approach to estimate a synthesis tree for the freshwater crayfish. The crayfish make an exceptional group to demonstrate the utility of the synthesis approach, as there recently have been a number of phylogenetic studies on the crayfishes along with a robust underlying taxonomic framework. Importantly, the crayfish have also been extensively assessed by an IUCN Red List team and therefore have accurate and up-to-date area and conservation status data available for analysis within a phylogenetic context. Here, we develop a synthesis phylogeny for the world's freshwater crayfish and examine the phylogenetic distribution of threat. We also estimate a molecular phylogeny based on all available GenBank crayfish sequences and use this tree to estimate divergence times and test for divergence rate variation. Finally, we conduct EDGE and HEDGE analyses and identify a number of species of freshwater crayfish of highest priority in conservation efforts. PMID:25561670

  10. 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

  11. Hidden diversity in the freshwater planktonic diatom Asterionella formosa.

    PubMed

    Van den Wyngaert, S; Möst, M; Freimann, R; Ibelings, B W; Spaak, P

    2015-06-01

    Many freshwater and marine algal species are described as having cosmopolitan distributions. Whether these widely distributed morphologically similar algae also share a similar gene pool remains often unclear. In the context of island biogeography theory, stronger spatial isolation deemed typical of freshwater lakes should restrict gene flow and lead to higher genetic differentiation among lakes. Using nine microsatellite loci, we investigate the genetic diversity of a widely distributed freshwater planktonic diatom, Asterionella formosa, across different lakes in Switzerland and the Netherlands. We applied a hierarchical spatial sampling design to determine the geographical scale at which populations are structured. A subset of the isolates was additionally analysed using amplified fragment length polymorphism (AFLP) markers. Our results revealed complex and unexpected population structure in A. formosa with evidence for both restricted and moderate to high gene flow at the same time. Different genetic markers (microsatellites and AFLPs) analysed with a variety of multivariate methods consistently revealed that genetic differentiation within lakes was much stronger than among lakes, indicating the presence of cryptic species within A. formosa. We conclude that the hidden diversity found in this study is expected to have implications for the further use of A. formosa in biogeographical, conservation and ecological studies. Further research using species-level phylogenetic markers is necessary to place the observed differentiation in an evolutionary context of speciation. PMID:25919789

  12. A new source of freshwater for Antarctica's coastal waters

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2011-06-01

    Research into submarine groundwater discharge (SGD), predominantly regarding its prevalence as a source of freshwater and nutrients to coastal ecosystems, has recently grown in prominence. Using a new groundwater discharge sensor specifically designed for use in the cold polar ocean, Uemura et al. measured the flows of freshwater streaming through the Antarctic subsurface and into the surrounding coastal waters. The researchers found that SGD rates measured in Lützow-Holm Bay in eastern Antarctica showed important differences from SGD rates measured elsewhere on Earth. At midlatitudes, discharge rates drop with increasing ocean depth, while the Antarctic flows were relatively consistent despite differences in depth among the seven survey sites scattered throughout the bay. In addition, the measured average flow rates, ranging from 0.85 × 10-7 to 9.5 × 10-7 meters per second, were 10-100 times higher than flow rates at similar depths made at midlatitudes. The authors also found that SDG rates oscillated with a period of 12.8 hours, peaking at low tide. Further, the discharge rates roughly tracked the size of the tide, having higher peaks in spring, when tides were strongest. The researchers propose that the most likely source of the freshwater flow is meltwater formed beneath the massive glaciers surrounding the bay. (Geophysical Research Letters, doi:10.1029/2010GL046394, 2011)

  13. Identifying and validating freshwater ecoregions in Jinan City, China

    NASA Astrophysics Data System (ADS)

    Yu, Songyan; Xu, Zongxue; Liu, Xingcai; Dou, Tongwen; Xu, Chen

    2015-09-01

    Freshwater ecoregion is currently widely used by biologists, conservators and resource managers. Most of ecoregion delineations are developed at the basin scale and are not fully adapted in a practical manner because operational water resources management is primarily conducted by political administrative departments. In this study, an ecoregion delineation framework was proposed to classify three-level ecoregions in Jinan City with geographic information systems and cluster analysis. The first level ecoregion was composed of three watersheds (a part of the Yellow River, Xiaoqing River and Tuhaimajia River) plus the urban area, which was primarily determined on the basis of the city administrative divisions and river watersheds. The classification of the second level ecoregion is primarily based on the spatial heterogeneity of land use. The third level ecoregion was delineated for each second level ecoregion by using the cluster analysis on water quality. At the same time, administrative boundaries were used to rectify the boundaries of each ecoregion in this study to facilitate the administration of each ecoregion. Furthermore, ecological health assessment (IBI) based on fish communities were employed to validate the freshwater ecoregion. The results demonstrated that 73.3% of ecoregions were in line with the distribution of fish IBI, indicating that the freshwater ecoregions are acceptable for future water resources management.

  14. Magnetic resonance imaging of live freshwater mussels (Unionidae)

    USGS Publications Warehouse

    Michael, Holliman F.; Davis, D.; Bogan, A.E.; Kwak, T.J.; Gregory, Cope W.; Levine, J.F.

    2008-01-01

    We examined the soft tissues of live freshwater mussels, Eastern elliptio Elliptio complanata, via magnetic resonance imaging (MRI), acquiring data with a widely available human whole-body MRI system. Anatomical features depicted in the profile images included the foot, stomach, intestine, anterior and posterior adductor muscles, and pericardial cavity. Noteworthy observations on soft tissue morphology included a concentration of lipids at the most posterior aspect of the foot, the presence of hemolymph-filled fissures in the posterior adductor muscle, the presence of a relatively large hemolymph-filled sinus adjacent to the posterior adductor muscle (at the ventral-anterior aspect), and segmentation of the intestine (a diagnostic description not reported previously in Unionidae). Relatively little is known about the basic biology and ecological physiology of freshwater mussels. Traditional approaches for studying anatomy and tissue processes, and for measuring sub-lethal physiological stress, are destructive or invasive. Our study, the first to evaluate freshwater mussel soft tissues by MRI, clarifies the body plan of unionid mussels and demonstrates the efficacy of this technology for in vivo evaluation of the structure, function, and integrity of mussel soft tissues. ?? 2008, The American Microscopical Society, Inc.

  15. Laboratory Experiments for Seawater Intrusion into Freshwater Aquifer with Heterogeneity

    NASA Astrophysics Data System (ADS)

    Maekawa, K.; Karasaki, K.; Takasu, T.

    2007-12-01

    It is important for safety assessment of high-level radioactive waste geologic disposal to understand groundwater flow in deep underground accurately. Especially, groundwater flow in the coastal area is considered to be quite complex that involves density and hydraulic gradient driven flow of freshwater and seawater. In order to understand the behavior of seawater intrusion into freshwater in deep underground, we constructed a laboratory equipment, 'Mini-MACRO' (MAss transport Characterization in host ROck). Mini-MACRO consists of three parts: a sandbox (0.5m x 0.25m x 0.1m) and a reservoir tank on each side containing saltwater simulating seawater and freshwater, respectively. Seawater intrusion experiments are conducted using glass beads (sub- millimeter in diameter) and colored saltwater in the sandbox with a transparent face plate to allow visual observation. We created several cases of experimental conditions to observe the seawater intrusion behavior into two-layered stratum against various hydraulic gradients and densities of saltwater resembling the so-called Henry Problem. We confirmed that the results using this equipment match numerical results under simple heterogeneous condition. These results contribute to the better understanding of seawater intrusion behavior and to increasing confidence in modeling methodology of groundwater flow and mass transport in deep underground through comparison with numerical analysis. We believe that it is crucial for the safety assessment of geologic disposal to integrate this knowledge.

  16. Homogenization patterns of the world’s freshwater fish faunas

    PubMed Central

    Villéger, Sébastien; Blanchet, Simon; Beauchard, Olivier; Oberdorff, Thierry; Brosse, Sébastien

    2011-01-01

    The world is currently undergoing an unprecedented decline in biodiversity, which is mainly attributable to human activities. For instance, nonnative species introduction, combined with the extirpation of native species, affects biodiversity patterns, notably by increasing the similarity among species assemblages. This biodiversity change, called taxonomic homogenization, has rarely been assessed at the world scale. Here, we fill this gap by assessing the current homogenization status of one of the most diverse vertebrate groups (i.e., freshwater fishes) at global and regional scales. We demonstrate that current homogenization of the freshwater fish faunas is still low at the world scale (0.5%) but reaches substantial levels (up to 10%) in some highly invaded river basins from the Nearctic and Palearctic realms. In these realms experiencing high changes, nonnative species introductions rather than native species extirpations drive taxonomic homogenization. Our results suggest that the “Homogocene era” is not yet the case for freshwater fish fauna at the worldwide scale. However, the distressingly high level of homogenization noted for some biogeographical realms stresses the need for further understanding of the ecological consequences of homogenization processes. PMID:22025692

  17. Predator-induced reduction of freshwater carbon dioxide emissions

    NASA Astrophysics Data System (ADS)

    Atwood, Trisha B.; Hammill, Edd; Greig, Hamish S.; Kratina, Pavel; Shurin, Jonathan B.; Srivastava, Diane S.; Richardson, John S.

    2013-03-01

    Predators can influence the exchange of carbon dioxide between ecosystems and the atmosphere by altering ecosystem processes such as decomposition and primary production, according to food web theory. Empirical knowledge of such an effect in freshwater systems is limited, but it has been suggested that predators in odd-numbered food chains suppress freshwater carbon dioxide emissions, and predators in even-numbered food chains enhance emissions. Here, we report experiments in three-tier food chains in experimental ponds, streams and bromeliads in Canada and Costa Rica in the presence or absence of fish (Gasterosteus aculeatus) and invertebrate (Hesperoperla pacifica and Mecistogaster modesta) predators. We monitored carbon dioxide fluxes along with prey and primary producer biomass. We found substantially reduced carbon dioxide emissions in the presence of predators in all systems, despite differences in predator type, hydrology, climatic region, ecological zone and level of in situ primary production. We also observed lower amounts of prey biomass and higher amounts of algal and detrital biomass in the presence of predators. We conclude that predators have the potential to markedly influence carbon dioxide dynamics in freshwater systems.

  18. Evolution of growth by genetic accommodation in Icelandic freshwater stickleback.

    PubMed

    Robinson, Beren W

    2013-12-01

    Classical Darwinian adaptation to a change in environment can ensue when selection favours beneficial genetic variation. How plastic trait responses to new conditions affect this process depends on how plasticity reveals to selection the influence of genotype on phenotype. Genetic accommodation theory predicts that evolutionary rate may sharply increase when a new environment induces plastic responses and selects on sufficient genetic variation in those responses to produce an immediate evolutionary response, but natural examples are rare. In Iceland, marine threespine stickleback that have colonized freshwater habitats have evolved more rapid individual growth. Heritable variation in growth is greater for marine full-siblings reared at low versus high salinity, and genetic variation exists in plastic growth responses to low salinity. In fish from recently founded freshwater populations reared at low salinity, the plastic response was strongly correlated with growth. Plasticity and growth were not correlated in full-siblings reared at high salinity nor in marine fish at either salinity. In well-adapted lake populations, rapid growth evolved jointly with stronger plastic responses to low salinity and the persistence of strong plastic responses indicates that growth is not genetically assimilated. Thus, beneficial plastic growth responses to low salinity have both guided and evolved along with rapid growth as stickleback adapted to freshwater. PMID:24132309

  19. Angiotensin I converting enzyme inhibitory peptide extracted from freshwater zooplankton.

    PubMed

    Lee, Jung Kwon; Lee, Min-Su; Park, Heum Gi; Kim, Se-Kwon; Byun, Hee-Guk

    2010-04-01

    In this study, hydrolysates obtained from the freshwater rotifer Brachionus calyciflonus were investigated for angiotensin I converting enzyme (ACE) inhibitory peptides. Freshwater rotifer protein was hydrolyzed using six separate enzymes in a batch reactor. The peptic hydrolysate had the highest ACE inhibitory activity compared to the other hydrolysates. The highest ACE inhibitory peptide was separated using Sephadex G-25 column chromatography and high-performance liquid chromatography on a C18 column. The 50% inhibitory concentration (IC(50)) value of purified ACE inhibitory peptide was 40.01 microg/mL. ACE inhibitory peptide was identified as being seven amino acid residues of Ala-Gln-Gly-Glu-Arg-His-Arg by N-terminal amino acid sequence analysis. The IC(50) value of purified ACE inhibitory peptide was 47.1 microM, and Lineweaver-Burk plots suggested that the peptide purified from rotifer protein acts as a competitive inhibitor against ACE. The results of this study suggest that peptides derived from freshwater rotifers may be beneficial as antihypertension compounds in functional foods or as pharmaceuticals. PMID:20170338

  20. Applied Astronomy: Asteroid Prospecting

    NASA Astrophysics Data System (ADS)

    Elvis, M.

    2013-09-01

    In the age of asteroid mining the ability to find promising ore-bearing bodies will be valuable. This will give rise to a new discipline- "Applied Astronomy". Just as most geologists work in industry, not in academia, the same will be true of astronomers. Just how rare or common ore-rich asteroids are likely to be, and the skills needed to assay their value, are discussed here, with an emphasis on remote - telescopic - methods. Also considered are the resources needed to conduct extensive surveys of asteroids for prospecting purposes, and the cost and timescale involved. The longer-term need for applied astronomers is also covered.

  1. Prospective bonding applications

    NASA Astrophysics Data System (ADS)

    Ancenay, H.; Benazet, D.

    1981-07-01

    Adhesive bonding in industry and in the laboratory is surveyed and prospects for its wider utilization are assessed. The economic impact of bonding technology on industry is discussed. Research is reviewed, centering on the development of nondestructive testing and inspection techniques. Traditional (wood) as well as new materials susceptible to bonding are considered. Applications in construction and civil engineering, in aeronautics, and in the automobile industry are covered. The use of glues in mechanical constructions, in assembling cylindrical parts, and in metal-metal bonding are examined. Hybrid assembling and bonding of composite materials are included.

  2. The Microbiota of Freshwater Fish and Freshwater Niches Contain Omega-3 Fatty Acid-Producing Shewanella Species

    PubMed Central

    McGraw, Joseph E.; Jensen, Brittany J.; Bishop, Sydney S.; Lokken, James P.; Dorff, Kellen J.; Ripley, Michael P.; Munro, James B.

    2015-01-01

    Approximately 30 years ago, it was discovered that free-living bacteria isolated from cold ocean depths could produce polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) (20:5n-3) or docosahexaenoic acid (DHA) (22:6n-3), two PUFA essential for human health. Numerous laboratories have also discovered that EPA- and/or DHA-producing bacteria, many of them members of the Shewanella genus, could be isolated from the intestinal tracts of omega-3 fatty acid-rich marine fish. If bacteria contribute omega-3 fatty acids to the host fish in general or if they assist some bacterial species in adaptation to cold, then cold freshwater fish or habitats should also harbor these producers. Thus, we undertook a study to see if these niches also contained omega-3 fatty acid producers. We were successful in isolating and characterizing unique EPA-producing strains of Shewanella from three strictly freshwater native fish species, i.e., lake whitefish (Coregonus clupeaformis), lean lake trout (Salvelinus namaycush), and walleye (Sander vitreus), and from two other freshwater nonnative fish, i.e., coho salmon (Oncorhynchus kisutch) and seeforellen brown trout (Salmo trutta). We were also able to isolate four unique free-living strains of EPA-producing Shewanella from freshwater habitats. Phylogenetic and phenotypic analyses suggest that one producer is clearly a member of the Shewanella morhuae species and another is sister to members of the marine PUFA-producing Shewanella baltica species. However, the remaining isolates have more ambiguous relationships, sharing a common ancestor with non-PUFA-producing Shewanella putrefaciens isolates rather than marine S. baltica isolates despite having a phenotype more consistent with S. baltica strains. PMID:26497452

  3. The Microbiota of Freshwater Fish and Freshwater Niches Contain Omega-3 Fatty Acid-Producing Shewanella Species.

    PubMed

    Dailey, Frank E; McGraw, Joseph E; Jensen, Brittany J; Bishop, Sydney S; Lokken, James P; Dorff, Kellen J; Ripley, Michael P; Munro, James B

    2016-01-01

    Approximately 30 years ago, it was discovered that free-living bacteria isolated from cold ocean depths could produce polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) (20:5n-3) or docosahexaenoic acid (DHA) (22:6n-3), two PUFA essential for human health. Numerous laboratories have also discovered that EPA- and/or DHA-producing bacteria, many of them members of the Shewanella genus, could be isolated from the intestinal tracts of omega-3 fatty acid-rich marine fish. If bacteria contribute omega-3 fatty acids to the host fish in general or if they assist some bacterial species in adaptation to cold, then cold freshwater fish or habitats should also harbor these producers. Thus, we undertook a study to see if these niches also contained omega-3 fatty acid producers. We were successful in isolating and characterizing unique EPA-producing strains of Shewanella from three strictly freshwater native fish species, i.e., lake whitefish (Coregonus clupeaformis), lean lake trout (Salvelinus namaycush), and walleye (Sander vitreus), and from two other freshwater nonnative fish, i.e., coho salmon (Oncorhynchus kisutch) and seeforellen brown trout (Salmo trutta). We were also able to isolate four unique free-living strains of EPA-producing Shewanella from freshwater habitats. Phylogenetic and phenotypic analyses suggest that one producer is clearly a member of the Shewanella morhuae species and another is sister to members of the marine PUFA-producing Shewanella baltica species. However, the remaining isolates have more ambiguous relationships, sharing a common ancestor with non-PUFA-producing Shewanella putrefaciens isolates rather than marine S. baltica isolates despite having a phenotype more consistent with S. baltica strains. PMID:26497452

  4. Changes in the Composition of the Fram Strait Freshwater Outflow

    NASA Astrophysics Data System (ADS)

    Dodd, Paul; Granskog, Mats; Fransson, Agneta; Chierici, Melissa; Stedmon, Colin

    2016-04-01

    Fram Strait is the largest gateway and only deep connection between the Arctic Ocean and the subpolar oceans. Monitoring the exchanges through Fram Strait allows us to detect and understand current changes occurring in the Arctic Ocean and to predict the effects of those changes on the Arctic and Subarctic climate and ecosystems. Polar water, recirculating Atlantic Water and deeper water masses exported from the Arctic Ocean through western Fram Strait are monitored year-round by an array of moored instruments along 78°50'N, continuously maintained by the Norwegian Polar Institute since the 1990s. Complimentary annual hydrographic sections have been repeated along the same latitude every September. This presentation will focus on biogeochemical tracer measurements collected along repeated sections from 1997-2015, which can be used to identify freshwater from different sources and reveal the causes of variations in total volume of freshwater exported e. g.: pulses of freshwater from the Pacific. Repeated tracer sections across Fram Strait reveal significant changes in the composition of the outflow in recent years, with recent sections showing positive fractions of sea ice meltwater at the surface near the core of the EGC, suggesting that more sea ice melts back into the surface than previously. The 1997-2015 time series of measurements reveals a strong anti-correlation between run-off and net sea ice meltwater inventories, suggesting that run-off and brine may be delivered to Fram Strait together from a common source. While the freshwater outflow at Fram Strait typically exhibits a similar run-off to net sea ice meltwater ratio to the central Arctic Ocean and Siberian shelves, we find that the ratio of run-off to sea ice meltwater at Fram Strait is decreasing with time, suggesting an increased surface input of sea ice meltwater in recent years. In 2014 and 2015 measurements of salinity, δ18O and total alkalinity were collected from sea ice cores as well as the

  5. A physically based model of global freshwater surface temperature

    NASA Astrophysics Data System (ADS)

    van Beek, Ludovicus P. H.; Eikelboom, Tessa; van Vliet, Michelle T. H.; Bierkens, Marc F. P.

    2012-09-01

    Temperature determines a range of physical properties of water and exerts a strong control on surface water biogeochemistry. Thus, in freshwater ecosystems the thermal regime directly affects the geographical distribution of aquatic species through their growth and metabolism and indirectly through their tolerance to parasites and diseases. Models used to predict surface water temperature range between physically based deterministic models and statistical approaches. Here we present the initial results of a physically based deterministic model of global freshwater surface temperature. The model adds a surface water energy balance to river discharge modeled by the global hydrological model PCR-GLOBWB. In addition to advection of energy from direct precipitation, runoff, and lateral exchange along the drainage network, energy is exchanged between the water body and the atmosphere by shortwave and longwave radiation and sensible and latent heat fluxes. Also included are ice formation and its effect on heat storage and river hydraulics. We use the coupled surface water and energy balance model to simulate global freshwater surface temperature at daily time steps with a spatial resolution of 0.5° on a regular grid for the period 1976-2000. We opt to parameterize the model with globally available data and apply it without calibration in order to preserve its physical basis with the outlook of evaluating the effects of atmospheric warming on freshwater surface temperature. We validate our simulation results with daily temperature data from rivers and lakes (U.S. Geological Survey (USGS), limited to the USA) and compare mean monthly temperatures with those recorded in the Global Environment Monitoring System (GEMS) data set. Results show that the model is able to capture the mean monthly surface temperature for the majority of the GEMS stations, while the interannual variability as derived from the USGS and NOAA data was captured reasonably well. Results are poorest for

  6. Methane Clathrate Hydrate Prospecting

    NASA Technical Reports Server (NTRS)

    Duxbury, N.; Romanovsky, V.

    2003-01-01

    A method of prospecting for methane has been devised. The impetus for this method lies in the abundance of CH4 and the growing shortages of other fuels. The method is intended especially to enable identification of subpermafrost locations where significant amounts of methane are trapped in the form of methane gas hydrate (CH4(raised dot)6H2O). It has been estimated by the U.S. Geological Survey that the total CH4 resource in CH4(raised dot) 6H2O exceeds the energy content of all other fossil fuels (oil, coal, and natural gas from non-hydrate sources). Also, CH4(raised dot)6H2O is among the cleanest-burning fuels, and CH4 is the most efficient fuel because the carbon in CH4 is in its most reduced state. The method involves looking for a proxy for methane gas hydrate, by means of the combination of a thermal-analysis submethod and a field submethod that does not involve drilling. The absence of drilling makes this method easier and less expensive, in comparison with prior methods of prospecting for oil and natural gas. The proposed method would include thermoprospecting in combination with one more of the other non-drilling measurement techniques, which could include magneto-telluric sounding and/or a subsurface-electrical-resistivity technique. The method would exploit the fact that the electrical conductivity in the underlying thawed region is greater than that in the overlying permafrost.

  7. Freshwater flow from estuarine creeks into northeastern Florida Bay

    USGS Publications Warehouse

    Hittle, Clinton; Patino, Eduardo; Zucker, Mark A.

    2001-01-01

    Water-level, water-velocity, salinity, and temperature data were collected from selected estuarine creeks to compute freshwater flow into northeastern Florida Bay. Calibrated equations for determining mean velocity from acoustic velocity were obtained by developing velocity relations based on direct acoustic measurements, acoustic line velocity, and water level. Three formulas were necessary to describe flow patterns for all monitoring sites, with R2 (coefficient of determination) values ranging from 0.957 to 0.995. Cross-sectional area calculations were limited to the main channel of the creeks and did not include potential areas of overbank flow. Techniques also were used to estimate discharge at noninstrumented sites by establishing discharge relations to nearby instrumented sites. Results of the relation between flows at instrumented and noninstrumented sites varied with R2 values ranging from 0.865 to 0.99. West Highway Creek was used to estimate noninstrumented sites in Long Sound, and Mud Creek was used to estimate East Creek in Little Madeira Bay. Mean monthly flows were used to describe flow patterns and to calculate net flow along the northeastern coastline. Data used in the study were collected from October 1995 through September 1999, which includes the El Nino event of 1998. During this period, about 80 percent of the freshwater flowing into the bay occurred during the wet season (May-October). The mean freshwater discharge for all five instrumented sites during the wet season from 1996 to 1999 is 106 cubic feet per second. The El Nino event caused a substantial increase (654 percent) in mean flows during the dry season (November-April) at the instrumented sites, ranging from 8.5 cubic feet per second in 1996-97 to 55.6 cubic feet per second in 1997-98. Three main flow signatures were identified when comparing flows at all monitoring stations. The most significant was the magnitude of discharges at Trout Creek, which carries about 50 percent of the

  8. Impact of slowdown of Atlantic overturning circulation on heat and freshwater transports

    NASA Astrophysics Data System (ADS)

    Kelly, Kathryn A.; Drushka, Kyla; Thompson, LuAnne; Le Bars, Dewi; McDonagh, Elaine L.

    2016-07-01

    Recent measurements of the strength of the Atlantic overturning circulation at 26°N show a 1 year drop and partial recovery amid a gradual weakening. To examine the extent and impact of the slowdown on basin wide heat and freshwater transports for 2004-2012, a box model that assimilates hydrographic and satellite observations is used to estimate heat transport and freshwater convergence as residuals of the heat and freshwater budgets. Using an independent transport estimate, convergences are converted to transports, which show a high level of spatial coherence. The similarity between Atlantic heat transport and the Agulhas Leakage suggests that it is the source of the surface heat transport anomalies. The freshwater budget in the North Atlantic is dominated by a decrease in freshwater flux. The increasing salinity during the slowdown supports modeling studies that show that heat, not freshwater, drives trends in the overturning circulation in a warming climate.

  9. Freshwater runoff and salinity distribution in the Loxahatchee River estuary, southeastern Florida, 1980-82

    USGS Publications Warehouse

    Russell, G.M.; McPherson, B.F.

    1984-01-01

    Freshwater mixed with seawater over a distance of 5 to 10 river miles in the Loxahatchee River estuary during a recent study. Large freshwater inflows vertically stratified the estuary and shifted the mixing zone seaward. In the northwest fork of the estuary, the saltwater-freshwater interface moved daily about 0.5 to 1.5 river miles as a result of tides, and annually about 3 to 5 miles as a result of seasonal changes in freshwater inflow. In the southwest fork, saltwater movement upstream was blocked by a gate and dam structure in Canal-18, 4.7 miles upstream from the Atlantic Ocean. Although Canal-18 discharged about one-third of the total freshwater tributary inflow to the estuary, the effects of canal discharge on salinity were limited to relatively brief periods. Much of the time, no freshwater was discharged. (USGS)

  10. Modelling residence-time response to freshwater input in Apalachicola Bay, Florida, USA

    NASA Astrophysics Data System (ADS)

    Huang, Wenrui; Spaulding, M.

    2002-10-01

    Residence time of an estuary can be used to estimate the rate of removal of freshwater and pollutants from river inflow. In this study, a calibrated three-dimensional hydrodynamic model was used to determine residence time in response to the change of freshwater input in Apalachicola Bay. The bay is about 40 km long and 7 km wide, with an average 3 m water depth. Through hydrodynamic model simulations, the spatial and temporal salinity and the total freshwater volume in the bay were calculated. Then the freshwater fraction method was used to estimate the residence time. Results indicate that the residence time in Apalachicola Bay typically ranges between 3 and 10 days for the daily freshwater input ranging from 177 m3/s to 4561 m3/s. Regression analysis of model results shows that an exponential regression equation can be used to correlate the estuarine residence time to changes of freshwater input.

  11. Terrestrial freshwater lenses in stable riverine settings: Occurrence and controlling factors

    NASA Astrophysics Data System (ADS)

    Werner, Adrian D.; Laattoe, Tariq

    2016-05-01

    Rivers in arid and semiarid regions often traverse saline aquifers, creating buoyant freshwater lenses in the adjoining riparian and floodplain zones. The occurrence of freshwater lenses where the river is otherwise gaining saline groundwater appears counterintuitive, given that both hydraulic and density forces act toward the river. In this paper, an analytical solution is presented that defines the extent of a stable, sharp-interface terrestrial freshwater lens (in cross section) in a riverine environment that otherwise contains saline groundwater moving toward the river. The method is analogous to the situation of an island freshwater lens, except in the riverine setting, the saltwater is mobile and the lens is assumed to be stagnant. The solution characterizes the primary controlling factors of riverine freshwater lenses, which are larger for situations involving lower hydraulic conductivities and rates of saltwater discharge to the river. Deeper aquifers, more transmissive riverbeds, and larger freshwater-saltwater density differences produce more extensive lenses. The analytical solution predicts the parameter combinations that preclude the occurrence of freshwater lenses. The utility of the solution as a screening method to predict the occurrence of terrestrial freshwater lenses is demonstrated by application to parameter ranges typical of the South Australian portion of the River Murray, where freshwater lenses occur in only a portion of the neighboring floodplains. Despite assumptions of equilibrium conditions and a sharp freshwater-saltwater interface, the solution for predicting the occurrence of riverine freshwater lenses presented in this study has immediate relevance to the management of floodplains in which freshwater lenses are integral to biophysical conditions.

  12. The Prospects Study and Desegregation.

    ERIC Educational Resources Information Center

    Puma, Michael J.

    1997-01-01

    Argues that greater caution is required when drawing conclusions from statistical results than the Armor study has done, and describes the "Prospects" study (begun in 1989), the largest longitudinal study of educational outcomes conducted in the United States. "Prospects" provides much data useful in evaluating the school desegregation situation…

  13. Prospective Memory Performance across Adolescence

    ERIC Educational Resources Information Center

    Wang, Lijuan; Kliegel, Matthias; Yang, Zhiliang; Liu, Wei

    2006-01-01

    In the present study, the authors explored age differences in event-based prospective memory (PM) across adolescence. The tasks consisted of an ongoing task (OT; i.e., personality questionnaire items, math problems) and an embedded prospective task that required participants to remember to make a special response whenever they encountered a PM cue…

  14. Prospect Theory and Coercive Bargaining

    ERIC Educational Resources Information Center

    Butler, Christopher K.

    2007-01-01

    Despite many applications of prospect theory's concepts to explain political and strategic phenomena, formal analyses of strategic problems using prospect theory are rare. Using Fearon's model of bargaining, Tversky and Kahneman's value function, and an existing probability weighting function, I construct a model that demonstrates the differences…

  15. Louisiana hydrologic atlas map no. 2 : Areal extent of freshwater in major aquifers of Louisiana

    USGS Publications Warehouse

    Smoot, Charles W.

    1986-01-01

    The areal availability of freshwater (cl content < 250 mg/L) in 14 major aquifers in Louisiana was investigated. The depth of occurrence of fresh groundwater in Louisiana is variable. The aquifers were mapped to show their areal extent from the outcrop or subcrop to the downdip limit of freshwater. Water in each aquifer becomes saline downdip; but in most areas an overlying (younger) aquifer contains freshwater. None of the major aquifer contains freshwater in northern Louisiana where the Vicksburg and Jackson groups crop out and the underlying Cockfield aquifer (Cockfield Formation) contains saline water. (Peters-PTT)

  16. Prospects at high energies

    SciTech Connect

    Quigg, C.

    1988-11-01

    I discuss some possibilities for neutrino experiments in the fixed-target environment of the SPS, Tevatron, and UNK, with their primary proton beams of 0.4, 0.9, and 3.0 TeV. The emphasis is on unfinished business: issues that have been recognized for some time, but not yet resolved. Then I turn to prospects for proton-proton colliders to explore the 1-TeV scale. I review the motivation for new physics in the neighborhood of 1 TeV and mention some discovery possibilities for high-energy, high-luminosity hadron colliders and the implications they would have for neutrino physics. I raise the possibility of the direct study of neutrino interactions in hadron colliders. I close with a report on the status of the SSC project. 38 refs., 17 figs.

  17. Prospecting with neutrinos

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    One of the latest attempts to explore the interface between physics and geophysics is the extravagant scheme of Alvaro De Rújula, Sheldon Glashow, Robert Wilson, and Georges Charpak, to be published in Physics Reports. In what these theoretical and experimental physicists described recently as “our mad project” (Physics Today, August 1983), a high-energy neutrino beam is to be used as a geophysical prospecting tool.The beam would be able to look for oil, natural gas, and high-atomic-number metal ores, and it would be able to profile the vertical density distribution of the earth. De Rújula et al. come to this project from the world of big physics machines, so it is natural to expect that the “Geotron,” the field instrument to supply and focus the neutrino beam, is to be big also.

  18. A comparative analysis of metacommunity types in the freshwater realm

    PubMed Central

    Heino, Jani; Soininen, Janne; Alahuhta, Janne; Lappalainen, Jyrki; Virtanen, Risto

    2015-01-01

    Most metacommunity studies have taken a direct mechanistic approach, aiming to model the effects of local and regional processes on local communities within a metacommunity. An alternative approach is to focus on emergent patterns at the metacommunity level through applying the elements of metacommunity structure (EMS; Oikos, 97, 2002, 237) analysis. The EMS approach has very rarely been applied in the context of a comparative analysis of metacommunity types of main microbial, plant, and animal groups. Furthermore, to our knowledge, no study has associated metacommunity types with their potential ecological correlates in the freshwater realm. We assembled data for 45 freshwater metacommunities, incorporating biologically highly disparate organismal groups (i.e., bacteria, algae, macrophytes, invertebrates, and fish). We first examined ecological correlates (e.g., matrix properties, beta diversity, and average characteristics of a metacommunity, including body size, trophic group, ecosystem type, life form, and dispersal mode) of the three elements of metacommunity structure (i.e., coherence, turnover, and boundary clumping). Second, based on those three elements, we determined which metacommunity types prevailed in freshwater systems and which ecological correlates best discriminated among the observed metacommunity types. We found that the three elements of metacommunity structure were not strongly related to the ecological correlates, except that turnover was positively related to beta diversity. We observed six metacommunity types. The most common were Clementsian and quasi-nested metacommunity types, whereas Random, quasi-Clementsian, Gleasonian, and quasi-Gleasonian types were less common. These six metacommunity types were best discriminated by beta diversity and the first axis of metacommunity ecological traits, ranging from metacommunities of producer organisms occurring in streams to those of large predatory organisms occurring in lakes. Our results showed

  19. In-Depth Tanscriptomic Analysis on Giant Freshwater Prawns

    PubMed Central

    Mohd-Shamsudin, Maizatul Izzah; Kang, Yi; Lili, Zhao; Tan, Tian Tian; Kwong, Qi Bin; Liu, Hang; Zhang, Guojie; Othman, Rofina Yasmin; Bhassu, Subha

    2013-01-01

    Gene discovery in the Malaysian giant freshwater prawn (Macrobrachium rosenbergii) has been limited to small scale data collection, despite great interest in various research fields related to the commercial significance of this species. Next generation sequencing technologies that have been developed recently and enabled whole transcriptome sequencing (RNA-seq), have allowed generation of large scale functional genomics data sets in a shorter time than was previously possible. Using this technology, transcriptome sequencing of three tissue types: hepatopancreas, gill and muscle, has been undertaken to generate functional genomics data for M. rosenbergii at a massive scale. De novo assembly of 75-bp paired end Ilumina reads has generated 102,230 unigenes. Sequence homology search and in silico prediction have identified known and novel protein coding candidate genes (∼24%), non-coding RNA, and repetitive elements in the transcriptome. Potential markers consisting of simple sequence repeats associated with known protein coding genes have been successfully identified. Using KEGG pathway enrichment, differentially expressed genes in different tissues were systematically represented. The functions of gill and hepatopancreas in the context of neuroactive regulation, metabolism, reproduction, environmental stress and disease responses are described and support relevant experimental studies conducted previously in M. rosenbergii and other crustaceans. This large scale gene discovery represents the most extensive transcriptome data for freshwater prawn. Comparison with model organisms has paved the path to address the possible conserved biological entities shared between vertebrates and crustaceans. The functional genomics resources generated from this study provide the basis for constructing hypotheses for future molecular research in the freshwater shrimp. PMID:23734171

  20. Nitrate-dependent anaerobic methane oxidation in a freshwater sediment

    NASA Astrophysics Data System (ADS)

    Norði, Katrin á.; Thamdrup, Bo

    2014-05-01

    Anaerobic oxidation of methane coupled to denitrification (DAOM) is a novel process of potential importance to the regulation of methane emissions from freshwater environments. We established nitrate-enriched microcosms of sediment from a freshwater pond in order to quantify the role of this process in a simulated natural redox zonation. The microcosms were allowed to acclimate to nitrate levels of 1-2 mmol L-1 in the overlying water for 16 months leading to a nitrate penetration of 4 cm. The nitrate enrichment significantly stimulated AOM relative to controls, and based on the similar concentrations of sulfate and reactive Fe(III) in the control sediment we conclude that the observed AOM was coupled to denitrification. DAOM occurred at rates that were two orders of magnitude lower than aerobic methane oxidation rates reported in freshwater sediments, and the process appeared to be limited by nitrate or nitrite even at millimolar nitrate concentrations. By contrast, ammonium was efficiently consumed at the base of the nitrate zone, presumably by the anammox process. Although DAOM was stimulated by nitrate enrichment, there were no significant differences between the methane emission from the control and nitrate-enriched microcosms. Our results provide the first experimental evaluation of the kinetics of DAOM in whole sediment cores and indicate that AOM coupled to denitrification can consume a substantial part of the methane flux in nitrate-rich environments. Because it is much less efficient in scavenging methane than its aerobic counterpart, the anaerobic process will, however, mainly be of significance in the regulation of methane emission from oxygen-depleted systems.

  1. Walking the tightrope: trends in African freshwater systematic ichthyology.

    PubMed

    Skelton, P H; Swartz, E R

    2011-12-01

    Africa is blessed with an abundance and rich diversity of freshwater fishes, reflecting its Gondwanan history and geographical position astride the equator. Africa is, however, relatively poorly serviced scientifically, in this respect presenting a challenge to the tension between conserving biodiversity and sustainable development. Biosystematics has experienced several paradigm shifts in the past half century, including the rise of cladistics and more recently the adoption of molecular DNA applications to taxonomy and phylogeny and the assembly and manipulation of large data sets in an era of major development of bioinformatics. The richness of African biodiversity is a magnet to the global systematic community that, to a degree, offsets the disadvantage of an impoverished indigenous scientific capacity. Conservation biology, however, is rooted more closely to the local situation and therefore requires indigenous taxonomic services that are inevitably scarce. Balancing this network of tensions between scientific knowledge generation and application is like walking a tightrope for existing African scientific resources, and to cope it is essential to embrace modern innovative approaches such as barcoding to identify organisms. This paper considers the historical development of African freshwater ichthyology, presents a suite of recent examples illustrating trends in systematic ichthyology in Africa and draws conclusions to suggest that both traditional and new-age approaches to taxonomy are necessary for a complete understanding and appreciation of African freshwater fish diversity and its conservation. The chosen examples also suggest that the tensions between the approaches can be effectively managed provided exponents work collaboratively. The emerging evidence indicates that the combined skills and insight of complex scientific teams including systematists, ecologists, molecular biologists and earth scientists are needed to resolve the deep complexity of

  2. Urban microbial ecology of a freshwater estuary of Lake Michigan

    PubMed Central

    Fisher, Jenny C.; Newton, Ryan J.; Dila, Deborah K.

    2015-01-01

    Freshwater estuaries throughout the Great Lakes region receive stormwater runoff and riverine inputs from heavily urbanized population centers. While human and animal feces contained in this runoff are often the focus of source tracking investigations, non-fecal bacterial loads from soil, aerosols, urban infrastructure, and other sources are also transported to estuaries and lakes. We quantified and characterized this non-fecal urban microbial component using bacterial 16S rRNA gene sequences from sewage, stormwater, rivers, harbor/estuary, and the lake surrounding Milwaukee, WI, USA. Bacterial communities from each of these environments had a distinctive composition, but some community members were shared among environments. We used a statistical biomarker discovery tool to identify the components of the microbial community that were most strongly associated with stormwater and sewage to describe an “urban microbial signature,” and measured the presence and relative abundance of these organisms in the rivers, estuary, and lake. This urban signature increased in magnitude in the estuary and harbor with increasing rainfall levels, and was more apparent in lake samples with closest proximity to the Milwaukee estuary. The dominant bacterial taxa in the urban signature were Acinetobacter, Aeromonas, and Pseudomonas, which are organisms associated with pipe infrastructure and soil and not typically found in pelagic freshwater environments. These taxa were highly abundant in stormwater and sewage, but sewage also contained a high abundance of Arcobacter and Trichococcus that appeared in lower abundance in stormwater outfalls and in trace amounts in aquatic environments. Urban signature organisms comprised 1.7% of estuary and harbor communities under baseflow conditions, 3.5% after rain, and >10% after a combined sewer overflow. With predicted increases in urbanization across the Great Lakes, further alteration of freshwater communities is likely to occur with

  3. Upper thermal tolerances of early life stages of freshwater mussels

    USGS Publications Warehouse

    Pandolfo, Tamara J.; Cope, W. Gregory; Arellano, Consuelo; Bringolf, Robert B.; Barnhart, M. Christopher; Hammer, E

    2010-01-01

    Freshwater mussels (order Unioniformes) fulfill an essential role in benthic aquatic communities, but also are among the most sensitive and rapidly declining faunal groups in North America. Rising water temperatures, caused by global climate change, industrial discharges, drought, or land development, could further challenge imperiled unionid communities. The aim of our study was to determine the upper thermal tolerances of the larval (glochidia) and juvenile life stages of freshwater mussels. Glochidia of 8 species of mussels were tested: Lampsilis siliquoidea, Potamilus alatus, Ligumia recta, Ellipsaria lineolata,Lasmigona complanata, Megalonaias nervosa, Alasmidonta varicosa, and Villosa delumbis. Seven of these species also were tested as juveniles. Survival trends were monitored while mussels held at 3 acclimation temperatures (17, 22, and 27°C) were exposed to a range of common and extreme water temperatures (20–42°C) in standard acute laboratory tests. The average median lethal temperature (LT50) among species in 24-h tests with glochidia was 31.6°C and ranged from 21.4 to 42.7°C. The mean LT50 in 96-h juvenile tests was 34.7°C and ranged from 32.5 to 38.8°C. Based on comparisons of LT50s, thermal tolerances differed among species for glochidia, but not for juveniles. Acclimation temperature did not affect thermal tolerance for either life stage. Our results indicate that freshwater mussels already might be living close to their upper thermal tolerances in some systems and, thus, might be at risk from rising environmental temperatures.

  4. Freshwater and heat transports from global ocean synthesis

    NASA Astrophysics Data System (ADS)

    Valdivieso, M.; Haines, K.; Zuo, H.; Lea, D.

    2014-01-01

    An eddy-permitting ¼° global ocean reanalysis based on the Operational Met Office FOAM data assimilation system has been run for 1989-2010 forced by ERA-Interim meteorology. Freshwater and heat transports are compared with published estimates globally and in each basin, with special focus on the Atlantic. The meridional transports agree with observations within errors at most locations, but where eddies are active the transports by the mean flow are nearly always in better agreement than the total transports. Eddy transports are down gradient and are enhanced relative to a free run. They may oppose or reinforce mean transports and provide 40-50% of the total transport near midlatitude fronts, where eddies with time scales <1 month provide up to 15%. Basin-scale freshwater convergences are calculated with the Arctic/Atlantic, Indian, and Pacific oceans north of 32°S, all implying net evaporation of 0.33 ± 0.04 Sv, 0.65 ± 0.07 Sv, and 0.09 ± 0.04 Sv, respectively, within the uncertainty of observations in the Atlantic and Pacific. The Indian is more evaporative and the Southern Ocean has more precipitation (1.07 Sv). Air-sea fluxes are modified by assimilation influencing turbulent heat fluxes and evaporation. Generally, surface and assimilation fluxes together match the meridional transports, indicating that the reanalysis is close to a steady state. Atlantic overturning and gyre transports are assessed with overturning freshwater transports southward at all latitudes. At 26°N eddy transports are negligible, overturning transport is 0.67 ± 0.19 Sv southward and gyre transport is 0.44 ± 0.17 Sv northward, with divergence between 26°N and the Bering Strait of 0.13 ± 0.23 Sv over 2004-2010.

  5. Standard methods for sampling North American freshwater fishes

    USGS Publications Warehouse

    Bonar, Scott A.; Hubert, Wayne A.; Willis, David W.

    2009-01-01

    This important reference book provides standard sampling methods recommended by the American Fisheries Society for assessing and monitoring freshwater fish populations in North America. Methods apply to ponds, reservoirs, natural lakes, and streams and rivers containing cold and warmwater fishes. Range-wide and eco-regional averages for indices of abundance, population structure, and condition for individual species are supplied to facilitate comparisons of standard data among populations. Provides information on converting nonstandard to standard data, statistical and database procedures for analyzing and storing standard data, and methods to prevent transfer of invasive species while sampling.

  6. Book review: Ecology of North American freshwater fishes

    USGS Publications Warehouse

    Bonar, Scott A.

    2014-01-01

    This book will be important in courses for upper undergraduates studying fish ecology or for graduate students. However, it will also be an excellent reference for the fishery manager who asks ‘Why does this fish do that?’. With the wealth of great information contained in Ross’ book, chances are an answer will be found. Review info: Ecology of North American freshwater fishes. Edited by Stephen T. Ross, 2013. ISBN: 978-0520249455, 408 pp.

  7. Collecting and Preserving Marine and Freshwater Isopoda (Crustacea: Peracarida)

    PubMed Central

    2015-01-01

    Abstract Background Isopoda are the most diverse Crustacea. In order to encourage the study of isopod crustaceans and their use in biodiversity studies, systematics, ecology, physiology and more, one needs to know who the isopods are and where to find them. New information This is a short “how to” guide focusing on the free-living marine and freshwater isopods: where they live and how to collect and preserve them. The tools and techniques described here are simple, but invaluable in accessing the natural history of these remarkable creatures. PMID:26023284

  8. Freshwater diatomite deposits in the western United States

    USGS Publications Warehouse

    Wallace, Alan R.; Frank, David G.; Founie, Alan

    2006-01-01

    Freshwater diatomite deposits in the Western United States are found in lake beds that formed millions of years ago. These diatom-rich sediments are among the Nation's largest commercial diatomite deposits. Each deposit contains billions of tiny diatom skeletons, which are widely used for filtration, absorption, and abrasives. New studies by the U.S. Geological Survey (USGS) are revealing how ancient lakes in the Western States produced such large numbers of diatoms. These findings can be used by both land-use managers and mining companies to better evaluate diatomite resources in the region.

  9. Variation in freshwater input to the Eastern US coastal ecosystem

    NASA Astrophysics Data System (ADS)

    Feng, D.; Yoon, Y.; Beighley, E., II; Hughes, R.; Kimbro, D.

    2014-12-01

    Phragmites is one of the most invasive plants in North American wetlands. Although its spread in coastal marshes has been linked by independent studies to urbanization, eutrophication, and salinity change, there is good evidence that these factors may interactively determine invasion success and in turn, the ecosystem services provided by marshes. We hypothesize that the invasion of Phragmites is linked to changes in freshwater inputs due to climate and/or land use change. El Nino/Southern Oscillation (ENSO), originating in the sea surface temperature anomalies (warm or cold) in the eastern tropical Pacific Ocean, is a notable and prominent signal in inter-annual climatic variation. Recent studies shows that the probability of strong El Nino events may increase in the future. In this study, we will investigate the teleconnections between freshwater inputs to the coastal zone along the eastern U.S. and ENSO indices, and attempt to explore the predictability of temporal and spatial variation of freshwater inputs based on ENSO conditions. To quantify changes in freshwater input in this region, hydrologic modeling, remote sensing and field measurements are combined. The Hillslope River Routing (HRR) model is used to simulate hourly streamflow from all watersheds from southern Florida to northern Maine draining into the Atlantic Ocean. The modeling effort utilizes satellite precipitation (Tropical Rainfall Measuring Mission Product 3B42v7: 2001-current with a 3-hr temporal resolution and 0.25 degree spatial resolution), land surface temperature and vegetation measures (Moderate Resolution Imaging Spectroradiometer, MODIS, products: 2001-current with a monthly temporal resolution and 0.05 degree spatial resolution). To account for land cover change, annual MODIS land cover data and time varying population statics are merged to estimate annual land cover characteristics for each sub-catchment within the study region. Static datasets for soils and ground elevations are

  10. A meta-analysis of the freshwater trophic cascade.

    PubMed Central

    Brett, M T; Goldman, C R

    1996-01-01

    The generality of the trophic cascade has been an intensely debated topic among ecologists. We conducted a meta-analysis of 54 separate enclosure and pond experiments that measured the response of the zooplankton and phytoplankton to zooplanktivorous fish treatments. These results provide unequivocal support for the trophic cascade hypothesis in freshwater food webs. Zooplanktivorous fish treatments resulted in reduced zooplankton biomass and increased phytoplankton biomass. The trophic cascade was weakly dampened at the level of the phytoplankton. However, the response of the phytoplankton to the trophic cascade was highly skewed, with very strong responses in slightly more than one-third of the cases and weak responses in the others. PMID:11607694

  11. Toxicity of 33 NCS to freshwater fish and sea lamprey

    USGS Publications Warehouse

    Marking, Leif L.; King, Everett L.; Walker, Charles R.; Howell, John H.

    1970-01-01

    The chemical 33NCS (3'-chloro-3-nitrosalicylanilide) was evaluated as a fish control agent and as a larvicide for sea lampreys at the Fish Control Laboratories of the Bureau of Sport Fisheries and Wildlife and the Hammond Bay Biological Station of the Bureau of Commercial Fisheries. The chemical is rapidly toxic to many species. Sea lampreys, bowfin, and channel catfish are the most sensitive species. Carp are more sensitive than trouts or sunfishes. Use of 33NCS in selective control of freshwater fishes or sea lampreys requires precise control because its toxicity is strongly influenced by variations in water quality.

  12. Effects of freshwater petroleum contamination on amphibian hatching and metamorphosis

    SciTech Connect

    Mahaney, P.A. . Dept. of Zoology)

    1994-02-01

    This study examined the effects of freshwater petroleum contamination on amphibian reproduction. The primary objectives were to assess the potential environmental and physiological impacts of runoff petroleum products on amphibians, using the green tree frog (Hyla cinerea) as a target species and engine crankcase oil as a contaminant. Egg hatching success, tadpole growth, and successful metamorphosis were measured in four concentrations of oil. The effects of oil on food source was also studied. Hatching success was not measurably influenced by the presence of oil. Tadpole and alga growth were negatively associated with the presence of oil. No tadpoles from the high concentration of oil treatments successfully metamorphosed.

  13. Genetic Inheritance of Female and Male Morphotypes in Giant Freshwater Prawn Macrobrachium rosenbergii

    PubMed Central

    2014-01-01

    Giant freshwater prawn (GFP) Macrobrachium rosenbergii is unique with males categorized in five different morphotypes (small claw, orange claw, blue claw, old blue claw and no claw males) and females in three reproductive statuses (mature ovary, berried and spawned females). In the present study we examined genetic inheritance of female and male morphotypes, their body weights and genetic associations between morphotypes and body traits. Restricted maximum likelihood fitting a multi-trait animal model was performed on a total of 21,459 body records collected over five generations in a GFP population selected for high growth rate. The estimates of variance components showed that there were substantial differences in additive genetic variance in body weight between male morphotypes. The low and significantly different from one genetic correlations between the expressions of body weight in male morphotypes also suggest that these traits should be treated as genetically different traits in selective breeding programs. By contrast, body weights of female types are essentially the same characters as indicated by the high genetic correlations between homologous trait expressions. In addition to body weight, male morphotypes and female reproductive statuses were treated as traits in themselves and were analysed as binary observations using animal and sire linear mixed models, and logit and probit threshold models. The estimates of heritability back-transformed from the liability scale were in good agreement with those obtained from linear mixed models, ranging from 0.02 to 0.43 for male morphotypes and 0.06 to 0.10 for female types. The genetic correlations among male morphoptypes were generally favourable. Body weight showed negative genetic associations with SM (−0.96), whereas those of body weight with other male morphotypes were positive (0.25 to 0.76). Our results showed that there is existence of heritable (additive genetic) component for male morphotypes, giving

  14. Evaluation of DNA extraction methods for freshwater eukaryotic microalgae.

    PubMed

    Eland, Lucy E; Davenport, Russell; Mota, Cesar R

    2012-10-15

    The use of molecular methods to investigate microalgal communities of natural and engineered freshwater resources is in its infancy, with the majority of previous studies carried out by microscopy. Inefficient or differential DNA extraction of microalgal community members can lead to bias in downstream community analysis. Three commercially available DNA extraction kits have been tested on a range of pure culture freshwater algal species with diverse cell walls and mixed algal cultures taken from eutrophic waste stabilization ponds (WSP). DNA yield and quality were evaluated, along with DNA suitability for amplification of 18S rRNA gene fragments by polymerase chain reaction (PCR). QiagenDNeasy(®) Blood and Tissue kit (QBT), was found to give the highest DNA yields and quality. Denaturant Gradient Gel Electrophoresis (DGGE) was used to assess the diversity of communities from which DNA was extracted. No significant differences were found among kits when assessing diversity. QBT is recommended for use with WSP samples, a conclusion confirmed by further testing on communities from two tropical WSP systems. The fixation of microalgal samples with ethanol prior to DNA extraction was found to reduce yields as well as diversity and is not recommended. PMID:22853974

  15. Multiple antimicrobial resistance in Enterobacteriaceae isolates from pristine freshwater.

    PubMed

    Lima-Bittencourt, C I; Cursino, L; Gonçalves-Dornelas, H; Pontes, D S; Nardi, R M D; Callisto, M; Chartone-Souza, E; Nascimento, A M A

    2007-01-01

    A freshwater enterobacterial population (N = 111) was studied for antimicrobial and mercury resistance patterns, and for its possible association with biotic and abiotic factors in that environment. Conventional biochemical tests identified Klebsiella sp, Morganella sp, Serratia sp, Escherichia sp, Enterobacter sp, Edwarsiella sp, Proteus sp, Citrobacter sp, Providencia sp, and Kluyvera sp. There was no correlation between antimicrobial resistance patterns of isolates and bacterial genera, but resistance patterns varied among water samples and between seasons. Resistance to multiple antimicrobials was common (61%). The percentage of bacteria resistant to at least one antimicrobial differed between the rainy (100%) and dry seasons (89%). Resistance to beta-lactams and chloramphenicol was the most frequent and resistance to amikacin, gentamicin and kanamycin was less frequent. The main water variables examined (abiotic factors pH and temperature; biotic factor chlorophyll a concentration) did not influence antimicrobial resistance. Significant impact on freshwater enterobacteria, as evidenced by antimicrobial-multiple resistance and by the presence of bla(TEM) gene, may point to the fact that it has an important role in horizontal spread of resistance. PMID:17985304

  16. Toxicity of Metals to a Freshwater Snail, Melanoides tuberculata

    PubMed Central

    Shuhaimi-Othman, M.; Nur-Amalina, R.; Nadzifah, Y.

    2012-01-01

    Adult freshwater snails Melanoides tuberculata (Gastropod, Thiaridae) were exposed for a four-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminium (Al), and manganese (Mn) concentrations. Mortality was assessed and median lethal times (LT50) and concentrations (LC50) were calculated. LT50 and LC50 increased with the decrease in mean exposure concentrations and times, respectively, for all metals. The LC50 values for the 96-hour exposures to Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 0.14, 1.49, 3.90, 6.82, 8.46, 8.49, 68.23, and 45.59 mg L−1, respectively. Cu was the most toxic metal to M. tuberculata, followed by Cd, Zn, Pb, Ni, Fe, Mn, and Al (Cu > Cd > Zn > Pb > Ni > Fe > Mn > Al). Metals bioconcentration in M. tuberculata increases with exposure to increasing concentrations and Cu has the highest accumulation (concentration factor) in the soft tissues. A comparison of LC50 values for metals for this species with those for other freshwater gastropods reveals that M. tuberculata is equally sensitive to metals. PMID:22666089

  17. Toxicity of Metals to a Freshwater Ostracod: Stenocypris major

    PubMed Central

    Shuhaimi-Othman, Mohammad; Yakub, Nadzifah; Ramle, Nur-Amalina; Abas, Ahmad

    2011-01-01

    Adults of freshwater ostracod Stenocypris major (Crustacea, Candonidae) were exposed for a four-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminium (Al), and manganese (Mn) concentrations. Mortality was assessed, and median lethal times (LT50) and concentrations (LC50) were calculated. LT50 and LC50 increased with the decrease in mean exposure concentrations and times, respectively, for all metals. LC50s for 96 hours for Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 25.2, 13.1, 1189.8, 526.2, 19743.7, 278.9, 3101.9, and 510.2 μg/L, respectively. Metals bioconcentration in S. major increases with exposure to increasing concentrations, and Cd was the most toxic to S. major, followed by Cu, Fe, Mn, Pb, Zn, Al, and Ni (Cd>Cu>Fe>Mn>Pb>Zn>Al>Ni). Comparison of LC50 values for metals for this species with those for other freshwater crustacean reveals that S. major is equally or more sensitive to metals than most other tested crustacean. PMID:21559091

  18. Wave-Induced Groundwater Flows in a Freshwater Beach Aquifer

    NASA Astrophysics Data System (ADS)

    Malott, S. S.; Robinson, C. E.; O'Carroll, D. M.

    2014-12-01

    Wave-induced recirculation across the sediment-water interface can impact the transport of pollutants through a beach aquifer and their ultimate flux into coastal waters. The fate of nutrients (e.g. from septic and agricultural sources) and fecal indicator bacteria (e.g. E. coil) near the sediment-water interface are of particular concern as these pollutants often lead to degradation of recreational water quality and nearshore ecosystems. This paper presents detailed field measurements of groundwater flows in a freshwater beach aquifer on Lake Huron over periods of intensified wave conditions. Quantifying wave-driven processes in a freshwater beach aquifer enables wave effects to be studied in isolation from density and tidal effects that complicate groundwater flows in marine beaches. Water exchange across the sediment-water interface and groundwater flow patterns were measured using groundwater wells, arrays of vertically nested pressure transducers and manometers. Results show that wave action induces rapid infiltration/exfiltration across the sediment-water interface and a larger recirculation cell through the beach aquifer. Field data is used to validate a numerical groundwater model of wave-induced groundwater flows. While prior studies have simulated the effects of waves on beach groundwater flows, this study is the first attempt to validate these sophisticated modeling approaches. Finally, field data illustrating the impact of wave-induced groundwater flows on nutrient and bacteria fate and transport in beach aquifers will also be presented.

  19. Acute toxicity of cypermethrin on the freshwater mussel Unio gibbus.

    PubMed

    Khazri, Abdelhafidh; Sellami, Badreddine; Dellali, Mohamed; Corcellas, Cayo; Eljarrat, Ethel; Barceló, Damià; Mahmoudi, Ezzeddine

    2015-05-01

    Cypermethrin is a synthetic pyrethroid insecticide used worldwide in agriculture, home pest control, food stuff protection and disease vector control. We investigate the potential of cypermethrin to induce oxidative stress and enzyme activities within the gills of freshwater mussel Unio gibbus. This study was carried out under laboratory conditions using two nominal cypermethrin concentrations C1 (100µg/L) and C2 (150µg/L) during 96h. The measured concentrations of cypermethrin using GC-MS-MS in the treatment aquariums were respectively 59.7 µg/L and 97.5µg/L. Antioxidant enzyme activities (superoxide dismutase (SOD) and catalase (CAT)) as well as H2O2, malondialdehyde (MDA) and protein carbonyl (PCO) levels were assessed. An exposure during 96h induced the SOD activity at the highest concentration. The CAT activity and H2O2 level were increased significantly (P<0.05) in gills following a dose-dependent profile. Cypermethrin also generated an increase in malondialdehyde (MDA) levels reaching the highest value at the high concentration. The considered parameters can be used as biomarkers of exposure to cypermethrin. Freshwater mussel U. gibbus can be potentially employed in biomonitoring surveys of such threatened ecosystems. PMID:25681606

  20. Remobilisation of uranium from contaminated freshwater sediments by bioturbation

    NASA Astrophysics Data System (ADS)

    Lagauzère, S.; Motelica-Heino, M.; Viollier, E.; Stora, G.; Bonzom, J. M.

    2014-06-01

    Benthic macro-invertebrate bioturbation can influence the remobilisation of uranium (U) initially associated with freshwater sediments, resulting in a high release of this pollutant through the overlying water column. Given the potential negative effects on aquatic biocenosis and the global ecological risk, it appears crucial to improve our current knowledge concerning the biogeochemical behaviour of U in sediments. The present study aimed to assess the biogeochemical modifications induced by Tubifex tubifex (Annelida, Clitellata, Tubificidae) bioturbation within the sediment in order to explain such a release of U. To reach this goal, U distribution between solid and solute phases of a reconstructed benthic system (i.e. in mesocosms) inhabited or not by T. tubifex worms was assessed in a 12-day laboratory experiment. Thanks notably to fine-resolution (mm-scale) measurements (e.g. "diffusive equilibrium in thin-films" DET gel probes for porewater, bioaccumulation in worms) of U and main chemical species (iron, sulfate, nitrate and nitrite), this work (i) confirmed that the removal of bottom sediment particles to the surface through the digestive tract of worms greatly favoured oxidative loss of U in the water column, and (ii) demonstrated that both U contamination and bioturbation of T. tubifex substantially influenced major microbial-driven biogeochemical reactions in sediments (e.g. stimulation of denitrification, sulfate reduction and iron dissolutive reduction). This study provides the first demonstration of biogeochemical modifications induced by bioturbation in freshwater U-contaminated sediments.

  1. Remobilisation of uranium from contaminated freshwater sediments by bioturbation

    NASA Astrophysics Data System (ADS)

    Lagauzère, S.; Motelica-Heino, M.; Viollier, E.; Stora, G.; Bonzom, J. M.

    2013-10-01

    Previous studies have demonstrated that benthic macro-invertebrate bioturbation can influence the remobilization of uranium initially associated with freshwater sediments resulting in a high release of this pollutant through the overlying water column. Giving the potential negative effects on aquatic biocenosis and the global ecological risk, it appeared crucial to improve our current knowledge concerning the uranium biogeochemical behaviour in sediments. The present study aimed to assess the biogeochemical modifications induced by Tubifex tubifex (Annelida, Clitellata, Tubificidae) bioturbation within the sediment permitting to explain such a release of uranium. To reach this goal, uranium distribution between solid and solute phases of a reconstructed benthic system (i.e. in mesocosms) inhabited or not by T. tubifex worms was assessed in a 12 day laboratory experiment. Thanks notably to fine resolution (mm-scale) measurements (e.g. DET gels probes for porewater, bioaccumulation in worms) of uranium and main chemical species (iron, sulfate, nitrate, nitrite), this work permitted (i) to confirm that the removal of bottom sediment particles to the surface through the digestive tract of worms greatly favours the oxidative loss of uranium in the water column, and (ii) to demonstrate that both uranium contamination and bioturbation of T. tubifex substantially influence major microbial-driven biogeochemical reactions in sediments (e.g. stimulation of denitrification, sulfate-reduction and iron dissolutive reduction). This study provides the first demonstration of biogeochemical modifications induced by bioturbation in freshwater uranium-contaminated sediments.

  2. Quantifying Greenland freshwater flux underestimates in climate models

    NASA Astrophysics Data System (ADS)

    Little, Christopher M.; Piecuch, Christopher G.; Chaudhuri, Ayan H.

    2016-05-01

    Key processes regulating the mass balance of the Greenland Ice Sheet (GIS) are not represented in current-generation climate models. Here using output from 19 different climate models forced with a high-end business-as-usual emissions pathway, we compare modeled freshwater fluxes (FWF) to a parameterization based on midtropospheric temperature. By the mid 21st century, parameterized GIS FWF is 478 ± 215 km3 yr-1 larger than modeled—over 3 times the 1992-2011 rate of GIS mass loss. By the late 21st century, ensemble mean parameterized GIS FWF anomalies are comparable to FWF anomalies over the northern North Atlantic Ocean, equivalent to approximately 11 cm of global mean sea level rise. The magnitude and spread of these underestimates underscores the need for assessments of the coupled response of the ocean to increased FWF that recognize: (1) the widely varying freshwater budgets of each model and (2) uncertainty in the relationship between GIS FWF and atmospheric temperature.

  3. The role of moisture transport in the arctic freshwater cycle

    NASA Astrophysics Data System (ADS)

    Tang, W.; Liu, W.

    2004-12-01

    This study focuses on understanding the impact of recent Arctic warming to the regional freshwater cycle from the perspective of the atmospheric integrated moisture transport (IMT), estimated based on measurements by multi- spaceborne- sensors. As one of the important components in the polar water/ice balance, IMT is traditionally derived from inadequate rawinsonde measurements. A method is developed to retrieve IMT over oceans using spaceborne scatterometer and microwave radiometer observations. More than five years (from August 1999 to present) daily IMT fields, at 0.5∞x0.5∞ resolution over global ocean, were produced by combining measurements from NASA scatterometer SeaWinds on QuikSCAT (QSCAT) and the Special Sensor Microwave/ Imagers (SSM/I) from Defense Meteorological Satellite Program (DMSP). Retrieved IMT fields have demonstrated credible annual and interannual variations in polar regions. Taking advantage of unprecedented coverage and resolution of satellite data, we were able to depict the temporal and spatial variation of IMT across the boundary of Greenland ice-sheet along a simulated coastline surrounding the Greenland, and revealed its correlation with observed abnormal Greenland ice-sheet melting during 2002 and 2003. The IMT data was also analyzed in the context of global water cycle to explore the linkage between changes in arctic freshwater cycle and global climate.

  4. Toxic potential of five freshwater Phormidium species (Cyanoprokaryota).

    PubMed

    Teneva, Ivanka; Dzhambazov, Balik; Koleva, Lyubka; Mladenov, Rumen; Schirmer, Kristin

    2005-05-01

    Among the Cyanoprokaryota (blue-green algae), the genus Phormidium has thus far rarely been studied with respect to toxin production and potentially resulting human and environmental health effects. We here show that five previously unexplored freshwater species of this genus (Ph. bijugatum, Ph. molle, Ph. papyraceum, Ph. uncinatum, Ph. autumnale) are indeed capable of producing bioactive compounds. Phormidium extracts caused weight loss as well as neuro/hepatotoxic symptoms in mice, and in the case of Ph. bijugatum even death. Very low levels of saxitoxins and microcystins, as confirmed by ELISA, were insufficient to explain this toxicity and the differing toxic potencies of the Phormidium species. Qualitative HPLC analyses confirmed different substance patterns and in the future could aid in the separation of fractions for more detailed substance characterisation. The results in vivo were confirmed in vitro using cells of human, mouse and fish. The fish cells responded least sensitive but proved useful in studying the temperature dependence of the toxicity by the Phormidium samples. Further, the human cells were more sensitive than the mouse cells thus suggesting that the former may be a more appropriate choice for studying the impact of Phormidium to man. Among the human cells, two cancer cell lines were more responsive to one of the samples than a normal cell line, thereby indicating a potential anti-tumour activity. Thus, the five freshwater Phormidium species should be considered in environmental risk assessment but as well, as a source of therapeutic agents. PMID:15804520

  5. Ecosystem connectivity: anadromous fish migration linked to freshwater amphipods

    NASA Astrophysics Data System (ADS)

    Macavoy, S. E.; Fogel, M. L.; Fong, D.; Hanson, N.

    2009-12-01

    Anadromous fish migrate to coastal streams to spawn each spring and may transfer marine derived nutrients to oligotrophic tidal freshwater. River herring (Alosa sp) are the dominant anadromous genus in Virginia, USA. This study investigates whether marine nutrients derived by the spawning Alosa were incorporated into benthic invertebrates by using the stable isotopes of carbon and nitrogen. Spawning Alosa had higher δ13C and δ15N than resident freshwater omnivorous fishes (-18.5 and 13.9‰ versus -25.7 and 11.8‰). In a tidal stream supporting abundant spawning Alosa, significant 13C and 15N enrichment was observed among stream invertebrates, particularly in the amphipod Gammarus fasciatus, coincident with the Alosa spawning migration. Among G. fasciatus, δ13C increased from -28.5 to -26.0‰ between early and late April then fell to -28.1‰ in early June. A similar trend was observed in mayflies (Heptageniidae). In an adjacent tidal stream that did not support spawning Alosa, enrichment among invertebrates was not observed. Particulate organic matter and sediments from both streams remained 13C and 15N depleted during the Alosa spawning run (between -29 and -28‰, 0.5 and 3.0‰ respectively), suggesting that marine material was not present. Although marine organic material may have been incorporated into stream invertebrates, it did not become a substantial component of other ecosystem components measured.

  6. Hotspots of anaerobic ammonium oxidation at land-freshwater interfaces

    NASA Astrophysics Data System (ADS)

    Zhu, Guibing; Wang, Shanyun; Wang, Weidong; Wang, Yu; Zhou, Leiliu; Jiang, Bo; Op den Camp, Huub J. M.; Risgaard-Petersen, Nils; Schwark, Lorenz; Peng, Yongzhen; Hefting, Mariet M.; Jetten, Mike S. M.; Yin, Chengqing

    2013-02-01

    For decades, the conversion of organic nitrogen to dinitrogen gas by heterotrophic bacteria, termed heterotrophic denitrification, was assumed to be the main pathway of nitrogen loss in natural ecosystems. Recently, however, autotrophic bacteria have been shown to oxidize ammonium in the absence of oxygen, yielding dinitrogen gas. This process, termed anammox, accounts for over 50% of nitrogen loss in marine ecosystems. However, the significance of anammox in freshwater ecosystems has remained uncertain. Here, we report the occurrence of anammox hotspots at land-freshwater interfaces of lake riparian zones in North China, using molecular and isotopic tracing technologies. Laboratory incubations measuring anammox activity at substrate concentrations no more than 10% of those observed in situ yielded some of the highest potential activities reported for natural environments to date. Potential rates of anammox peaked in sediments sampled from the interface between land and water, as did the abundance of annamox bacteria. Scaling our findings up to the entire lake system, we estimate that interfacial anammox hotspots account for the loss of 103gNm-2yr-1 from this lake region, and around one fifth of the nitrogen lost from the land-water interface.

  7. Molecular diversity of avian schistosomes in Danish freshwater snails.

    PubMed

    Christiansen, Anne Ø; Olsen, Annette; Buchmann, Kurt; Kania, Per W; Nejsum, Peter; Vennervald, Birgitte J

    2016-03-01

    Avian schistosomes are widespread parasites of snails and waterfowl and may cause cercarial dermatitis (swimmer's itch) in humans, a disease that is frequently reported in European countries. These parasites are known to occur in Denmark, but here, we applied a new approach using molecular tools to identify the parasites at species level. In order to do that, 499 pulmonate freshwater snails (Radix sp., Lymnaea stagnalis, Stagnicola sp. and Planorbarius corneus) were sampled from 12 lakes, ponds, and marshes in the greater Copenhagen area. Avian schistosome cercariae were identified by microscopy and subjected to molecular investigation by sequencing and phylogenetic analysis of the 5.8S and ITS2 ribosomal DNA for species identification. Additionally, snail hosts belonging to the genus Radix were identified by sequencing and phylogenetic analysis of partial ITS2 ribosomal DNA. Three out of 499 snails shed different species of Trichobilharzia cercariae: Trichobilharzia szidati was isolated from L. stagnalis, Trichobilharzia franki from Radix auricularia and Trichobilharzia regenti from Radix peregra. In the light of the public health risk represented by bird schistosomes, these findings are of concern and, particularly, the presence of the potentially neuro-pathogenic species, T. regenti, in Danish freshwaters calls for attention. PMID:26573519

  8. Biodiversity and distribution of polar freshwater DNA viruses.

    PubMed

    Aguirre de Cárcer, Daniel; López-Bueno, Alberto; Pearce, David A; Alcamí, Antonio

    2015-06-01

    Viruses constitute the most abundant biological entities and a large reservoir of genetic diversity on Earth. Despite the recent surge in their study, our knowledge on their actual biodiversity and distribution remains sparse. We report the first metagenomic analysis of Arctic freshwater viral DNA communities and a comparative analysis with other freshwater environments. Arctic viromes are dominated by unknown and single-stranded DNA viruses with no close relatives in the database. These unique viral DNA communities mostly relate to each other and present some minor genetic overlap with other environments studied, including an Arctic Ocean virome. Despite common environmental conditions in polar ecosystems, the Arctic and Antarctic DNA viromes differ at the fine-grain genetic level while sharing a similar taxonomic composition. The study uncovers some viral lineages with a bipolar distribution, suggesting a global dispersal capacity for viruses, and seemingly indicates that viruses do not follow the latitudinal diversity gradient known for macroorganisms. Our study sheds light into the global biogeography and connectivity of viral communities. PMID:26601189

  9. Behavioral responses of freshwater mussels to experimental dewatering

    USGS Publications Warehouse

    Galbraith, Heather S.; Blakeslee, Carrie J.; Lellis, William A.

    2015-01-01

    Understanding the effects of flow alteration on freshwater ecosystems is critical for predicting species responses and restoring appropriate flow regimes. We experimentally evaluated the effects of 3 dewatering rates on behavior of 6 freshwater mussel species in the context of water-removal rates observed in 21 Atlantic Coast rivers. Horizontal movement differed significantly among species and dewatering rates, but a significant species × dewatering interaction suggested that these factors influence movement in complex ways. Species differences in movement were evident only in controls and under slow dewatering rates, but these differences disappeared at moderate and fast dewatering rates. Burrowing behavior did not differ with respect to species identity or dewatering rate. The proportion of individuals that became stranded did not differ among species, but most individuals became stranded under low and moderate dewatering, and all individuals became stranded under fast dewatering. Mortality after stranding differed strongly among species along a gradient from 25% inPyganodon cataracta to 92% in Alasmidonta marginata. Together, these results suggest that species behavior may differ under gradual dewatering, but all species in our study are poorly adapted for rapid dewatering. Most of the 21 rivers we assessed experienced dewatering events comparable to our moderate rate, and several experienced events comparable to our fast rate. Dewatering events that exceed the movement or survival capability of most mussel species can be expected to result in assemblage-wide impacts. Consequently, the rate of water level change may be important in refining target flow conditions for restoration.

  10. Genotoxicity monitoring of freshwater environments using caged carp (Cyprinus carpio).

    PubMed

    Klobucar, Göran I V; Stambuk, Anamaria; Pavlica, Mirjana; Sertić Perić, Mirela; Kutuzović Hackenberger, Branimir; Hylland, Ketil

    2010-01-01

    The present study deals with genotoxicity assessment of freshwaters using caged carp (Cyprinus carpio). Carps were transplanted from a fish-farm to three differently polluted sites in eastern Croatia. Two polluted sites were situated in the river Drava, downstream from the cities of Belisće and Osijek, while the reference site was in the Nature Park Kopacki rit, a preserved wetland area with limited anthropogenic influence. Exposure lasted for 3 weeks and was repeated for 3 years (2002-2004). DNA damage was assessed in erythrocytes of the exposed animals by the Comet assay and micronucleus test (MNT). In order to evaluate possible differences in stress responses to polluted water in situ and in aquaria a laboratory exposure was performed with water from the studied location in the second year of the study. Carp from the sites with high anthropogenic influence (Belisće and Osijek) had higher average DNA damage as expressed in both the MNT and Comet assay. Of the two, the Comet assay appeared to be more sensitive following both caging and aquaria exposures. The results from this study suggest that 3 weeks caging exposure of C. carpio may be a useful strategy to monitor for genotoxic agents in freshwater ecosystems. PMID:19626438

  11. Enumeration, Isolation, and Characterization of Beggiatoa from Freshwater Sediments †

    PubMed Central

    Strohl, William R.; Larkin, John M.

    1978-01-01

    An accurate most-probable-number enumeration method was developed for counting the number of Beggiatoa trichomes from various freshwater sediments. The medium consisted of extracted hay, diluted soil extract, 0.05% acetate, and 15 to 35 U of catalase per ml. The same enrichment medium, but without the acetate, was the best enrichment medium from which to obtain pure cultures because it supported good growth of the beggiatoas without allowing them to be overgrown by other bacteria. A total of 32 strains of Beggiatoa were isolated from seven different freshwater habitats and partially characterized. The strains were separated into five groups based on several preliminary characteristics. Four of the groups contained cells with trichomes of approximately the same diameter (1.5 to 2.7 μm) and may be Beggiatoa leptomitiformis or an unnamed species. The fifth group appeared to be Beggiatoa alba. With the exception of three strains, all of the strains deposited sulfur in the presence of hydrogen sulfide, and all strains grew heterotrophically and deposited poly-β-hydroxybutyrate and volutin when grown on acetate supplemented with low concentrations of other organic nutrients. Thin sections of sulfur-bearing trichomes indicated that the sulfur granules were external to the cytoplasmic membrane and that they were surrounded by an additional membrane. Images PMID:16345330

  12. Toxicity of tributyltin (TBT) to the freshwater planarian Schmidtea mediterranea.

    PubMed

    Ofoegbu, Pearl U; Simão, Fátima C P; Cruz, Andreia; Mendo, Sónia; Soares, Amadeu M V M; Pestana, João L T

    2016-04-01

    The freshwater planarian Schmidtea mediterranea, one of the best characterized animal models for regeneration research and developmental biology, is being recognised as a useful species for ecotoxicological studies. Sensitive endpoints related to planarians' behaviour and regeneration can be easily evaluated after exposure to environmental stressors. In this work the sensitivity of S. mediterranea to a gradient of environmentally relevant concentrations of TBT was studied using multiple endpoints like survival, locomotion, head regeneration and DNA damage. In addition, a feeding assay based on planarian's predatory behaviour was performed. Results indicated that TBT is toxic to planarians with LC50's of 1.87 μg L(-1) Sn and 1.31 μg L(-1) Sn at 48 h and 96 h of exposure respectively. Sub-lethal exposures to TBT significantly reduced locomotion and feeding, delayed head regeneration and caused DNA damage in planarians. The behavioural endpoints (feeding and locomotion) and head regeneration were the most sensitive parameters followed by DNA damage. Similar to other aquatic model organisms, S. mediterranea showed high sensitivity towards TBT exposure. Based on our results, and though further research is required concerning their sensitivity to other pollutants, the use of freshwater planarians as a model species in ecotoxicology is discussed. PMID:26802264

  13. A water quality index for recreation in Brazilian freshwaters.

    PubMed

    Azevedo Lopes, F W; Davies-Colley, R J; Von Sperling, E; Magalhães, A P

    2016-04-01

    Use of water for leisure activities has long been prevalent in human societies, especially where the climate is favorable. Water resources with appealing conditions for primary contact recreational activities include rivers, waterfall plunge pools, dams and lakes, as well as sea coasts. Recreational use has specific demands for water quality, particularly as regards risks to human health such as exposure to pathogenic organisms, toxic substances, and submerged hazards. In Brazil, there is insufficient monitoring of bathing water conditions and currently used methodology has some limitations particularly the lack of guidance on interpretation of variables other than faecal bacterial indicators. The objectives of this study were: (1) to establish variables contributing to assessment of freshwater bathing conditions in Brazil; (2) to develop an integrated index of suitability-for-use for bathing in Brazil; and (3) to improve the methodology for assessing bathing water quality in Brazil. Based on a metadata analysis and consultation with Brazilian water professionals, a water quality index was developed incorporating the variables: Escherichia coli, cyanobacterial density, turbidity (visual clarity) and pH. This index should advance the management of recreational waters in Brazil, by improving the evaluation of freshwater bathing conditions and protecting the health of frequent users. PMID:27105410

  14. Development of intermediate foodstuff derived from freshwater fish in China

    NASA Astrophysics Data System (ADS)

    Wang, Xichang; Fukuda, Yutaka; Chen, Shunsheng; Yokoyama, Masahito; Cheng, Yudong; Yuan, Chunhong; Qu, Yinghong; Sakaguchi, Morihiko

    2005-07-01

    According to the three-dimensional contour maps showing the gel-forming properties of surimi derived from freshwater fish, 8 species of surimi were classified into two types. The V-valley type surimi (silver carp, big-head carp, Chinese snake head and blunt snout bream) shows easy setting, low resistance to gel collapse, high enhancement ability with two-step heating, and narrow optimum heating temperature and time area, which are of the same characteristics as the wall-eye pollack surimi. In contrast, the Plateau type surimi (tilapia, grass carp, mud carp and common carp) exhibits difficult setting, high resistance to gel collapse, no enhancement ability with two-step heating, and wide optimum heating temperature and time area. There are seasonal changes of gelling properties of silver carp surimi, and the setting ability of surimi gel is higher in winter and lower in summer. The marine fish meat gels and the freshwater fish meat gels have the same acceptability for inland Chinese according to the sensory evaluation results. A slight increase in sensory scorings of kamaboko gels occurred when the extract from walleye pollack muscle was added, especially in the odor scoring of silver carp kamaboko gels.

  15. Changes to freshwater systems affecting Arctic infrastructure and natural resources

    NASA Astrophysics Data System (ADS)

    Instanes, Arne; Kokorev, Vasily; Janowicz, Richard; Bruland, Oddbjørn; Sand, Knut; Prowse, Terry

    2016-03-01

    The resources component of the Arctic Freshwater Synthesis focuses on the potential impact of future climate and change on water resources in the Arctic and how Arctic infrastructure and exploration and production of natural resources are affected. Freshwater availability may increase in the Arctic in the future in response to an increase in middle- and high-latitude annual precipitation. Changes in type of precipitation, its seasonal distribution, timing, and rate of snowmelt represent a challenge to municipalities and transportation networks subjected to flooding and droughts and to current industries and future industrial development. A reliable well-distributed water source is essential for all infrastructures, industrial development, and other sectorial uses in the Arctic. Fluctuations in water supply and seasonal precipitation and temperature may represent not only opportunities but also threats to water quantity and quality for Arctic communities and industrial use. The impact of future climate change is varying depending on the geographical area and the current state of infrastructure and industrial development. This paper provides a summary of our current knowledge related to the system function and key physical processes affecting northern water resources, industry, and other sectorial infrastructure.

  16. Novel Virophages Discovered in a Freshwater Lake in China

    PubMed Central

    Gong, Chaowen; Zhang, Weijia; Zhou, Xuewen; Wang, Hongming; Sun, Guowei; Xiao, Jinzhou; Pan, Yingjie; Yan, Shuling; Wang, Yongjie

    2016-01-01

    Virophages are small double-stranded DNA viruses that are parasites of giant DNA viruses that infect unicellular eukaryotes. Here we identify a novel group of virophages, named Dishui Lake virophages (DSLVs) that were discovered in Dishui Lake (DSL): an artificial freshwater lake in Shanghai, China. Based on PCR and metagenomic analysis, the complete genome of DSLV1 was found to be circular and 28,788 base pairs in length, with a G+C content 43.2%, and 28 predicted open reading frames (ORFs). Fifteen of the DSLV1 ORFs have sequence similarity to known virophages. Two DSLV1 ORFs exhibited sequence similarity to that of prasinoviruses (Phycodnaviridae) and chloroviruses (Phycodnaviridae), respectively, suggesting horizontal gene transfer occurred between these large algal DNA viruses and DSLV1. 46 other virophages-related contigs were also obtained, including six homologous major capsid protein (MCP) gene. Phylogenetic analysis of these MCPs showed that DSLVs are closely related to OLV (Organic Lake virophage) and YSLVs (Yellowstone Lake virophages), especially to YSLV3, except for YSLV7. These results indicate that freshwater ecotopes are the hotbed for discovering novel virophages as well as understanding their diversity and properties. PMID:26834726

  17. Bubble size distribution under saltwater and freshwater breaking waves

    NASA Astrophysics Data System (ADS)

    Cartmill, John W.; Yang Su, Ming

    1993-11-01

    The chemical composition of salt water profoundly alters the process of microbubble formation and must be accounted for in extrapolating freshwater results to the ocean environment. Results are presented of the measurement of bubble size distributions generated by breaking waves in both freshwater and saltwater laboratory tanks. Bubble radii in the range of 34-1200 μ m were measured by an acoustic resonator at various positions and depths in a large-scale wave tank at Oregon State University. This experiment represents the first attempt to measure bubbles produced by breaking waves at this large scale in a saltwater tank. Mechanically generated wave groups, with maximum wave height of 4 ft, were used to produce breaking waves and bubble plumes comparable in scale with moderate ocean waves. During the experiment salt was added to bring the salinity of the water to 30%. This salinity alters the nature of the bubbles produced and their subsequent evolution. An order of magnitude increase in the number density over the entire size range was observed for salt water vs. fresh water.

  18. Contrasting "Fish" Diversity Dynamics between Marine and Freshwater Environments.

    PubMed

    Guinot, Guillaume; Cavin, Lionel

    2015-08-31

    Two theoretical models have been proposed to describe long-term dynamics of diversification: the equilibrium model considers the Earth as a closed system with a fixed maximum biological carrying capacity, whereas the expansion model hypothesizes a continuously increasing diversification of life. Based on the analysis of the fossil record of all organisms, Benton suggested contrasting models of diversity dynamics between marine and continental realms. Diversity in marine environments is characterized by phases of rapid diversification followed by plateaux, i.e., an equilibrium model directly derived from insular biogeography theories, whereas diversity in continental environments is characterized by exponential growth. Previous studies that aimed at testing these models with empirical data were based on datasets extracted directly from the reading of the vagaries of the raw fossil record, without correcting for common fossil record biases (preservation and sampling). Although correction of datasets for the incompleteness of the fossil record is now commonly performed for addressing long-term biodiversity variations, only a few attempts have been made to produce diversity curves corrected by phylogenetic data from extant and extinct taxa. Here we show that phylogenetically corrected diversity curves for "fish" (actinopterygians and elasmobranchs) during the last 200 million years fit an equilibrium model in the marine realm and an expansion model in the freshwater realm. These findings demonstrate that the rate of diversification has decreased for marine fish over the Cenozoic but is in sharp expansion for freshwater fish. PMID:26279235

  19. The Impacts of Modern Warfare on Freshwater Ecosystems

    NASA Astrophysics Data System (ADS)

    Francis, Robert A.

    2011-11-01

    There is increasing recognition and concern regarding the impacts of modern industrial warfare on the environment. Freshwater ecosystems are perhaps the most vulnerable to warfare-related impacts, which is of concern given that they provide so many essential environmental resources and services to society. Despite this, there has been little work to establish and quantify the types of impacts (both negative and positive) that warfare may have on such systems. This paper firstly highlights why rivers and lakes may be susceptible to warfare-related impacts, before synthesizing the available literature to explore the following main themes: intensification of wartime resource acquisition, use of water as an offensive or defensive weapon, direct and indirect effects of explosive ordnance, increased pollution, introduction of invasive alien species, and positive ecological impacts. This is then followed by a discussion of the implications of such impacts in relation to future warfare, including a consideration of the efficacy of existing legal instruments to protect the environment during conflict, and the trend for war to become more localized and `informal', and therefore less regulated. Finally, the paper identifies key research foci for understanding and mitigating the effects of warfare on freshwater ecosystems.

  20. High prevalence of trypanosome co-infections in freshwater fishes.

    PubMed

    Grybchuk-Ieremenko, Anastasiia; Losev, Alexander; Kostygov, Alexei Yu; Lukeš, Julius; Yurchenko, Vyacheslav

    2014-12-01

    One thousand three hundred seventy three fish specimens of eight different species from the vicinity of Kyiv, Ukraine, were examined for the presence of trypanosomes and 921 individuals were found to be infected. The prevalence of infection ranged from 24% in freshwater bream, Abramis brama (Linnaeus), to 100% in spined loach, Cobitis 'taenia' Linnaeus. The level of parasitaemia also varied significantly between generally mild infections in pikeperch, Sander lucioperca (Linnaeus), and heavy ones in C. 'taenia'. In most cases the infections with trypanosomes were asymptomatic. Cases of co-infection with species of Trypanoplasma Laveran et Mesnil, 1901 were documented for five out of eight examined host species. Molecular analysis of the 18S rDNA sequences revealed that four hosts, namely northern pike, Esox lucius Linnaeus, freshwater bream, spined loach and European perch, Perca fluviatilis Linnaeus, were simultaneously infected with two different trypanosome species. Our findings advocate the view that to avoid the risk posed by mixed infections, subsequent molecular taxonomic studies should be performed on clonal lines derived from laboratory cultures of fish trypanosomes. PMID:25651690

  1. Identification of Bacteria Responsible for Ammonia Oxidation in Freshwater Aquaria

    PubMed Central

    Burrell, Paul C.; Phalen, Carol M.; Hovanec, Timothy A.

    2001-01-01

    Culture enrichments and culture-independent molecular methods were employed to identify and confirm the presence of novel ammonia-oxidizing bacteria (AOB) in nitrifying freshwater aquaria. Reactors were seeded with biomass from freshwater nitrifying systems and enriched for AOB under various conditions of ammonia concentration. Surveys of cloned rRNA genes from the enrichments revealed four major strains of AOB which were phylogenetically related to the Nitrosomonas marina cluster, the Nitrosospira cluster, or the Nitrosomonas europaea-Nitrosococcus mobilis cluster of the β subdivision of the class Proteobacteria. Ammonia concentration in the reactors determined which AOB strain dominated in an enrichment. Oligonucleotide probes and PCR primer sets specific for the four AOB strains were developed and used to confirm the presence of the AOB strains in the enrichments. Enrichments of the AOB strains were added to newly established aquaria to determine their ability to accelerate the establishment of ammonia oxidation. Enrichments containing the Nitrosomonas marina-like AOB strain were most efficient at accelerating ammonia oxidation in newly established aquaria. Furthermore, if the Nitrosomonas marina-like AOB strain was present in the original enrichment, even one with other AOB, only the Nitrosomonas marina-like AOB strain was present in aquaria after nitrification was established. Nitrosomonas marina-like AOB were 2% or less of the cells detected by fluorescence in situ hybridization analysis in aquaria in which nitrification was well established. PMID:11722936

  2. Peak water limits to freshwater withdrawal and use

    PubMed Central

    Gleick, Peter H.; Palaniappan, Meena

    2010-01-01

    Freshwater resources are fundamental for maintaining human health, agricultural production, economic activity as well as critical ecosystem functions. As populations and economies grow, new constraints on water resources are appearing, raising questions about limits to water availability. Such resource questions are not new. The specter of “peak oil”—a peaking and then decline in oil production—has long been predicted and debated. We present here a detailed assessment and definition of three concepts of “peak water”: peak renewable water, peak nonrenewable water, and peak ecological water. These concepts can help hydrologists, water managers, policy makers, and the public understand and manage different water systems more effectively and sustainably. Peak renewable water applies where flow constraints limit total water availability over time. Peak nonrenewable water is observable in groundwater systems where production rates substantially exceed natural recharge rates and where overpumping or contamination leads to a peak of production followed by a decline, similar to more traditional peak-oil curves. Peak “ecological” water is defined as the point beyond which the total costs of ecological disruptions and damages exceed the total value provided by human use of that water. Despite uncertainties in quantifying many of these costs and benefits in consistent ways, more and more watersheds appear to have already passed the point of peak water. Applying these concepts can help shift the way freshwater resources are managed toward more productive, equitable, efficient, and sustainable use. PMID:20498082

  3. Arctic Freshwater Synthesis: Summary of key emerging issues

    NASA Astrophysics Data System (ADS)

    Prowse, T.; Bring, A.; Mârd, J.; Carmack, E.; Holland, M.; Instanes, A.; Vihma, T.; Wrona, F. J.

    2015-10-01

    In response to a joint request from the World Climate Research Program's Climate and Cryosphere Project, the International Arctic Science Committee, and the Arctic Council's Arctic Monitoring and Assessment Program an updated scientific assessment has been conducted of the Arctic Freshwater System (AFS), entitled the Arctic Freshwater Synthesis (AFSΣ). The major reason behind the joint request was an increasing concern that changes to the AFS have produced, and could produce even greater, changes to biogeophysical and socioeconomic systems of special importance to northern residents and also produce extra-Arctic climatic effects that will have global consequences. The AFSΣ was structured around six key thematic areas: atmosphere, oceans, terrestrial hydrology, terrestrial ecology, resources, and modeling, the review of each coauthored by an international group of scientists and published as separate manuscripts in this special issue of Journal of Geophysical Research-Biogeosciences. This AFSΣ summary manuscript reviews key issues that emerged during the conduct of the synthesis, especially those that are cross-thematic in nature, and identifies future research required to address such issues.

  4. Biodiversity and distribution of polar freshwater DNA viruses

    PubMed Central

    Aguirre de Cárcer, Daniel; López-Bueno, Alberto; Pearce, David A.; Alcamí, Antonio

    2015-01-01

    Viruses constitute the most abundant biological entities and a large reservoir of genetic diversity on Earth. Despite the recent surge in their study, our knowledge on their actual biodiversity and distribution remains sparse. We report the first metagenomic analysis of Arctic freshwater viral DNA communities and a comparative analysis with other freshwater environments. Arctic viromes are dominated by unknown and single-stranded DNA viruses with no close relatives in the database. These unique viral DNA communities mostly relate to each other and present some minor genetic overlap with other environments studied, including an Arctic Ocean virome. Despite common environmental conditions in polar ecosystems, the Arctic and Antarctic DNA viromes differ at the fine-grain genetic level while sharing a similar taxonomic composition. The study uncovers some viral lineages with a bipolar distribution, suggesting a global dispersal capacity for viruses, and seemingly indicates that viruses do not follow the latitudinal diversity gradient known for macroorganisms. Our study sheds light into the global biogeography and connectivity of viral communities. PMID:26601189

  5. Sublethal effects of cadmium exposure on freshwater teleosts

    SciTech Connect

    Watson, C.F.

    1988-01-01

    Biochemical and physiological parameters were examined to investigate the effects of sublethal concentrations on freshwater teleosts (golden shiner, Notemigonus crysoleucas; fathead minnow, Pimephales promelas; and bluegill sunfish, Lepomis macrochirus). Accumulation profiles of fish environmentally exposed to cadmium demonstrated that tissue distribution was time- and concentration-dependent. Gill tissue and internal organs accumulated significant residue levels of cadmium. Investigations concerned with the influence of cadmium on gill ATPase activity indicated that enzymatic activity was sensitive to cadmium exposure. An acute (48 h) comparative study was performed with the three species of freshwater teleosts. A stimulation of Na/K ATPase activity was observed at an exposure concentration of 1 {mu}g Cd/1 in bluegill sunfish and fathead minnows. At higher exposure concentrations (10 and 100 {mu}g Cd/1) an inhibition of enzymatic activity was observed. Gill Na/K ATPase activity in golden shiners was not significantly influenced by cadmium exposure. The observed insensitivity of Na/K ATPase in golden shiners may, in part, be related to high background concentrations of cadmium in gill tissue. An overall inhibitory response of gill Na/K ATPase was demonstrated in bluegill sunfish exposed to 10 and 100 {mu}g/1 of cadmium for 14 d. These results support the conclusion that biochemical and physiological parameters have potential for diagnostic use in assessing the overall environmental health of fish populations.

  6. Novel Virophages Discovered in a Freshwater Lake in China.

    PubMed

    Gong, Chaowen; Zhang, Weijia; Zhou, Xuewen; Wang, Hongming; Sun, Guowei; Xiao, Jinzhou; Pan, Yingjie; Yan, Shuling; Wang, Yongjie

    2016-01-01

    Virophages are small double-stranded DNA viruses that are parasites of giant DNA viruses that infect unicellular eukaryotes. Here we identify a novel group of virophages, named Dishui Lake virophages (DSLVs) that were discovered in Dishui Lake (DSL): an artificial freshwater lake in Shanghai, China. Based on PCR and metagenomic analysis, the complete genome of DSLV1 was found to be circular and 28,788 base pairs in length, with a G+C content 43.2%, and 28 predicted open reading frames (ORFs). Fifteen of the DSLV1 ORFs have sequence similarity to known virophages. Two DSLV1 ORFs exhibited sequence similarity to that of prasinoviruses (Phycodnaviridae) and chloroviruses (Phycodnaviridae), respectively, suggesting horizontal gene transfer occurred between these large algal DNA viruses and DSLV1. 46 other virophages-related contigs were also obtained, including six homologous major capsid protein (MCP) gene. Phylogenetic analysis of these MCPs showed that DSLVs are closely related to OLV (Organic Lake virophage) and YSLVs (Yellowstone Lake virophages), especially to YSLV3, except for YSLV7. These results indicate that freshwater ecotopes are the hotbed for discovering novel virophages as well as understanding their diversity and properties. PMID:26834726

  7. Effects of freshwater release to a marine bay.

    PubMed

    Legović, T; Janeković, I; Vilicić, D; Petricioli, D; Smoljan, Z

    2003-08-01

    Plans are in progress to increase freshwater inflow to the Zupski Bay, in south Dalmatia (between Dubrovnik and Cavtat, Adriatic Sea) as a consequence of a need to increase hydro-electric power production. The main question is: Would the adverse environmental impacts out-weight the benefit? Following has been found: a) temperature at public beaches will decrease, but the decrease in a worse case scenario will be below 0.5 degrees C and hence will not be felt by tourists, b) the probability for subsurface phytoplankton blooms will increase, but the blooms will be very limited in extent and concentration, and will not cause hypoxia at the bottom, c) benthic community in the eu- and sub-littoral, up to 200 m sea ward from the outflow, will be replaced in part by brackish tolerant species, d) overall trophic status of the bay will increase slightly, e) category of sanitary quality on surrounding beaches will not worsen. Given the above findings, the study recommends to proceed with the plans and increase freshwater inflow from 90 to 105 m3/s. PMID:12929796

  8. The impacts of modern warfare on freshwater ecosystems.

    PubMed

    Francis, Robert A

    2011-11-01

    There is increasing recognition and concern regarding the impacts of modern industrial warfare on the environment. Freshwater ecosystems are perhaps the most vulnerable to warfare-related impacts, which is of concern given that they provide so many essential environmental resources and services to society. Despite this, there has been little work to establish and quantify the types of impacts (both negative and positive) that warfare may have on such systems. This paper firstly highlights why rivers and lakes may be susceptible to warfare-related impacts, before synthesizing the available literature to explore the following main themes: intensification of wartime resource acquisition, use of water as an offensive or defensive weapon, direct and indirect effects of explosive ordnance, increased pollution, introduction of invasive alien species, and positive ecological impacts. This is then followed by a discussion of the implications of such impacts in relation to future warfare, including a consideration of the efficacy of existing legal instruments to protect the environment during conflict, and the trend for war to become more localized and 'informal', and therefore less regulated. Finally, the paper identifies key research foci for understanding and mitigating the effects of warfare on freshwater ecosystems. PMID:21904931

  9. Prospects of photoacoustic tomography

    PubMed Central

    Wang, Lihong V.

    2008-01-01

    Commercially available high-resolution three-dimensional optical imaging modalities—including confocal microscopy, two-photon microscopy, and optical coherence tomography—have fundamentally impacted biomedicine. Unfortunately, such tools cannot penetrate biological tissue deeper than the optical transport mean free path (∼1 mm in the skin). Photoacoustic tomography, which combines strong optical contrast and high ultrasonic resolution in a single modality, has broken through this fundamental depth limitation and achieved superdepth high-resolution optical imaging. In parallel, radio frequency-or microwave-induced thermoacoustic tomography is being actively developed to combine radio frequency or microwave contrast with ultrasonic resolution. In this Vision 20∕20 article, the prospects of photoacoustic tomography are envisaged in the following aspects: (1) photoacoustic microscopy of optical absorption emerging as a mainstream technology, (2) melanoma detection using photoacoustic microscopy, (3) photoacoustic endoscopy, (4) simultaneous functional and molecular photoacoustic tomography, (5) photoacoustic tomography of gene expression, (6) Doppler photoacoustic tomography for flow measurement, (7) photoacoustic tomography of metabolic rate of oxygen, (8) photoacoustic mapping of sentinel lymph nodes, (9) multiscale photoacoustic imaging in vivo with common signal origins, (10) simultaneous photoacoustic and thermoacoustic tomography of the breast, (11) photoacoustic and thermoacoustic tomography of the brain, and (12) low-background thermoacoustic molecular imaging. PMID:19175133

  10. ANAIS: Status and prospects

    NASA Astrophysics Data System (ADS)

    Amaré, J.; Cebrián, S.; Cuesta, C.; García, E.; Ginestra, C.; Martínez, M.; Oliván, M. A.; Ortigoza, Y.; Ortiz de Solórzano, A.; Pobes, C.; Puimedón, J.; Sarsa, M. L.; Villar, J. A.; Villar, P.

    2016-07-01

    ANAIS experiment will look for dark matter annual modulation with large mass of ultra-pure NaI(Tl) scintillators at the Canfranc Underground Laboratory (LSC), aiming to confirm the DAMA/LIBRA positive signal in a model-independent way. Two 12.5 kg each NaI(Tl) crystals provided by Alpha Spectra are currently taking data at the LSC. Present status of ANAIS detectors background and general performance is summarized; in particular, thanks to the high light collection efficiency prospects of lowering the threshold down to 1 keVee are reachable. Crystal radiopurity goals are fulfilled for 232Th and 238U chains and 40K activity, although higher than original goal, could be accepted; however, high 210Pb contamination out-of-equilibrium has been identified. More radiopure detectors are being built by Alpha Spectra. The ongoing high quantum efficiency PMT tests and muon veto characterization are also presented. Finally, the sensitivity of the experiment for the annual modulation in the WIMP signal, assuming the already achieved threshold and background in ANAIS-25 is shown. Further improvement should be achieved by reducing both threshold and background, as expected.

  11. German energy technology prospects.

    PubMed

    Popp, M

    1982-12-24

    After more than 25 years of development of nuclear power and almost 10 years of research and development in numerous areas of nonnuclear energy, there is now a good basis for judging the future prospects of energy technologies in the Federal Republic of Germany. The development of nuclear power has provided an important and economically advantageous new source of energy. Further efforts are needed to establish the nuclear fuel cycle in all stages and to exploit the potential of advanced reactors. In all other areas of energy technology, including energy conservation, new energy sources, and coal, economics has turned out to be the key problem, even at today's energy prices. Opportunities to overcome these economic problems through additional R & D are limited. There is some potential for special applications, and there are many technologies that could contribute to the energy supply of developing countries. In general, however, progress in energy conservation and the use of renewable energy sources will depend on the degree to which energy policy measures can improve their economic basis. For some technologies, such as solar thermal power stations and coal liquefaction, large-scale economic deployment cannot be foreseen today. Instead of establishing costly demonstration projects, emphasis will be put on improving key components of these technologies with the aim of having the most advanced technology available when the economic parameters are more favorable. PMID:17770150

  12. TRANSLOCATION OF NUTRIENTS BY FRESHWATER MUSSELS – ALTERATION OF ECOSYSTEM AND COMMUNITY PROCESSES

    EPA Science Inventory

    Nutrient demand and availability is a major driver of ecosystem processes. We examined the impact of freshwater mussels, a highly imperiled faunal group, on nitrogen (N) and phosphorus (P) cycling and storage in three Oklahoma streams. We found that filter-feeding by freshwater m...

  13. Relationships between community structure of freshwater mussels and host fishes in a central Ohio watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diversity of freshwater mussel communities has declined over the past several decades within watersheds in the Midwestern United States. Host fishes play an important role in the life cycle of freshwater mussels because they serve as hosts for parasitic mussel larvae to ensure successful mussel ...

  14. Epithelial Ion Transporters: A Physiological Model for Ion Effects on Freshwater Animals

    EPA Science Inventory

    Critical ions in freshwater animals are regulated in part by uptake from water through ionocytes on the gills or other epithelia. An ionoregulation literature review suggests a mechanism for adverse effects on freshwater animals is ion uptake inhibition associated with either ex...

  15. Global impacts of energy demand on the freshwater resources of nations.

    PubMed

    Holland, Robert Alan; Scott, Kate A; Flörke, Martina; Brown, Gareth; Ewers, Robert M; Farmer, Elizabeth; Kapos, Valerie; Muggeridge, Ann; Scharlemann, Jörn P W; Taylor, Gail; Barrett, John; Eigenbrod, Felix

    2015-12-01

    The growing geographic disconnect between consumption of goods, the extraction and processing of resources, and the environmental impacts associated with production activities makes it crucial to factor global trade into sustainability assessments. Using an empirically validated environmentally extended global trade model, we examine the relationship between two key resources underpinning economies and human well--being-energy and freshwater. A comparison of three energy sectors (petroleum, gas, and electricity) reveals that freshwater consumption associated with gas and electricity production is largely confined within the territorial boundaries where demand originates. This finding contrasts with petroleum, which exhibits a varying ratio of territorial to international freshwater consumption, depending on the origin of demand. For example, although the United States and China have similar demand associated with the petroleum sector, international freshwater consumption is three times higher for the former than the latter. Based on mapping patterns of freshwater consumption associated with energy sectors at subnational scales, our analysis also reveals concordance between pressure on freshwater resources associated with energy production and freshwater scarcity in a number of river basins globally. These energy-driven pressures on freshwater resources in areas distant from the origin of energy demand complicate the design of policy to ensure security of fresh water and energy supply. Although much of the debate around energy is focused on greenhouse gas emissions, our findings highlight the need to consider the full range of consequences of energy production when designing policy. PMID:26627262

  16. Global impacts of energy demand on the freshwater resources of nations

    PubMed Central

    Holland, Robert Alan; Scott, Kate A.; Flörke, Martina; Brown, Gareth; Ewers, Robert M.; Farmer, Elizabeth; Kapos, Valerie; Muggeridge, Ann; Taylor, Gail; Barrett, John; Eigenbrod, Felix

    2015-01-01

    The growing geographic disconnect between consumption of goods, the extraction and processing of resources, and the environmental impacts associated with production activities makes it crucial to factor global trade into sustainability assessments. Using an empirically validated environmentally extended global trade model, we examine the relationship between two key resources underpinning economies and human well-being—energy and freshwater. A comparison of three energy sectors (petroleum, gas, and electricity) reveals that freshwater consumption associated with gas and electricity production is largely confined within the territorial boundaries where demand originates. This finding contrasts with petroleum, which exhibits a varying ratio of territorial to international freshwater consumption, depending on the origin of demand. For example, although the United States and China have similar demand associated with the petroleum sector, international freshwater consumption is three times higher for the former than the latter. Based on mapping patterns of freshwater consumption associated with energy sectors at subnational scales, our analysis also reveals concordance between pressure on freshwater resources associated with energy production and freshwater scarcity in a number of river basins globally. These energy-driven pressures on freshwater resources in areas distant from the origin of energy demand complicate the design of policy to ensure security of fresh water and energy supply. Although much of the debate around energy is focused on greenhouse gas emissions, our findings highlight the need to consider the full range of consequences of energy production when designing policy. PMID:26627262

  17. SPATIAL VARIABILITY IN MUSSELS USED TO ASSESS BASE LEVEL NITROGEN ISOTOPE RATIO IN FRESHWATER ECOSYSTEMS

    EPA Science Inventory

    Freshwater mussels have been used to establish base level nitrogen isotope ratio values ( 15N) used in trophic position and food web studies in freshwater ecosystems. In this study, we assess the variability introduced when using unionid mussels in this manner by investigating th...

  18. Effects of ammonia on freshwater mussels in the St. Croix River

    USGS Publications Warehouse

    Newton, Teresa J.

    2004-01-01

    The St. Croix River contains a diverse and abundant group of freshwater mussels. The St. Croix is one of the few rivers in the Midwest not substantially affected by the invasion of the exotic zebra mussel, which encrusts and kills native freshwater mussels. Increased concentrations of ammonia in river sediments, however, poses a significant threat to mussels.

  19. Toxicity of crude oil to the metabolism of freshwater minor carp, Puntius sophore

    SciTech Connect

    Prasad, M.S.

    1987-08-01

    The effects of crude oil on the rate of metabolism in freshwater fishes have been little investigated. In the present investigation, the respiration rate in vitro and overall QO/sub 2/ in vivo of a freshwater minor carp Puntius sophore has been measured after exposing the fish to the lethal and sublethal doses of crude oil extracts for varying periods.

  20. Effects Of Five Years Of Nitrogen And Phosphorus Additions On A Zizaniopsis miliacea Tidal Freshwater Marsh

    EPA Science Inventory

    The purpose of this experiment was to determine if nitrogen (N) or phosphorus (P) acts as the limiting nutrient for tidal freshwater marsh vegetation. To answer this question, we added N, P, and N + P to a tidal freshwater marsh dominated by Zizaniopsis miliacea (Michx.) ...

  1. ACUTE LETHAL CONCENTRATIONS OF CAFFEINE ON NON-TARGET FRESHWATER ORGANISMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite the recent detection of caffeine in US streams, studies investigating caffeine's toxic effects on non-target freshwater organisms lack acute data for several standard surrogate species and chronic data for any freshwater species. The present study describes the mortality rate at different c...

  2. THE INFLUENCE OF FRESHWATER RUNOFF ON BIOMASS, MORPHOMETRICS, AND PRODUCTION OF THALASSIA TESTUDINUM. (R827453)

    EPA Science Inventory

    Efforts to restore more natural freshwater flows in South Florida will impact Biscayne Bay. In order to evaluate possible effects of decreased freshwater discharge on the seagrass Thalassia testudinum, we determined the biomass, density, morphometrics (width, length, nu...

  3. Changes of freshwater-lens thickness in basaltic island aquifers overlain by thick coastal sediments

    USGS Publications Warehouse

    Rotzoll, Kolja; Oki, Delwyn S.; El-Kadi, Aly I.

    2010-01-01

    Freshwater-lens thickness and long-term changes in freshwater volume in coastal aquifers are commonly assessed through repeated measurement of salinity profiles from monitor wells that penetrate into underlying salt water. In Hawaii, the thickest measured freshwater lens is currently 262 m in dike-free, volcanic-rock aquifers that are overlain by thick coastal sediments. The midpoint depth (depth where salinity is 50% salt water) between freshwater and salt water can serve as an indicator for freshwater thickness. Most measured midpoints have risen over the past 40 years, indicating a shrinking lens. The mean rate of rise of the midpoint from 1999–2009 varied locally, with faster rates in highly developed areas (1.0 m/year) and slower rates in less developed areas (0.5 m/year). The thinning of the freshwater lenses is the result of long-term groundwater withdrawal and reduced recharge. Freshwater/salt-water interface locations predicted from measured water levels and the Ghyben-Herzberg principle may be deeper than measured midpoints during some periods and shallower during other periods, although depths may differ up to 100 m in some cases. Moreover, changes in the midpoint are slower than changes in water level. Thus, water levels may not be a reliable indicator of the amount of freshwater in a coastal aquifer.

  4. TOXICITY AND METABOLISM STUDIES WITH EPA (ENVIRONMENTAL PROTECTION AGENCY) PRIORITY POLLUTANTS AND RELATED CHEMICALS IN FRESHWATER ORGANISMS

    EPA Science Inventory

    Twenty-two chemicals from the EPA priority pollutant list were studied for their acute and/or chronic toxicity to selected freshwater organisms. Freshwater species tested included the fathead minnow (Pimephales promelas), rainbow trout (Salmo gairdneri), bluegill sunfish (Lepomis...

  5. Growth of Vibrio cholerae O1 Ogawa Eltor in freshwater.

    PubMed

    Vital, Marius; Füchslin, Hans Peter; Hammes, Frederik; Egli, Thomas

    2007-07-01

    Growth of Vibrio cholerae O1 Ogawa Eltor was studied with a growth assay in which autoclaved and filtered (0.22 microm) freshwater was inoculated at low cell density (5 x 10(3) cells ml(-1)) and proliferation was followed with flow cytometry. Against the common view, V. cholerae was able to grow extensively in different kinds of freshwater. The bacterium multiplied in river water, lake water and effluent of a wastewater treatment plant up to a cell density of 1.55 x 10(6) cells ml(-1). In these samples, apparent assimilable organic carbon (AOC(app)) concentrations ranged from 52 up to 800 microg l(-1) and the results demonstrate a positive trend between the AOC(app) concentration and final cell concentration, suggesting that AOC was a key parameter governing growth of V. cholerae. No growth was observed in waters (tap and bottled drinking water) containing less than approximately 60 microg AOC(app) l(-1). When pure cultures of V. cholerae were grown on identical lake water at different temperatures (20, 25 and 30 degrees C) the maximum specific growth rates (micromax) achieved were 0.22 h(-1), 0.32 h(-1) and 0.45 h(-1), respectively. In addition, growth was characterized in lake water samples amended with different concentrations of NaCl. The highest micromax of V. cholerae was recorded at moderate salinity levels (5 g NaCl l(-1), micromax=0.84 h(-1)), whereas at 30 g NaCl l(-1) (micromax=0.30 h(-1)) or 0 g NaCl l(-1) (micromax)=0.40 h(-1)) specific growth rates were significantly reduced. In the water tested here, micro(max) of V. cholerae was always around 50 % of that exhibited by a freshwater community of indigenous bacteria enriched from the water sampling site. Direct batch competition experiments between V. cholerae and the lake water bacterial community were performed at different temperatures in which V. cholerae was enumerated in the total community using fluorescent-surface antibodies. In all cases V. cholerae was able to grow and constituted around 10

  6. Regional Variations in Freshwater Withdrawals in the US for 100 MSAs

    NASA Astrophysics Data System (ADS)

    Hunter, E.; Hornberger, G. M.; Worland, S. C.

    2015-12-01

    Water withdrawals reported every five years by the US Geologic Survey (USGS) indicate that total freshwater withdrawals in the US have declined since 1980. Many interpretations have been offered to justify this finding. This decline in freshwater withdrawals is particularly perplexing considering a steadily increasing population trend. This topic is further complicated by climate change, constantly evolving urban environments, and subsequent cases of water shortage. This exploratory analysis examines regional variations of this national phenomenon by analyzing public supply freshwater withdrawals for the 25 most populous Metropolitan Statistical Areas (MSAs) within each of the four regional divisions of the US, aggregated from county level data. Results indicate that there are distinct regional correlations in freshwater withdrawal and population. Case study cities within each region are selected from the data set for a multi-disciplinary analysis including: regional and local variation on freshwater withdrawals, implications on urban policy, and impacts on urban water acquisition.

  7. Extensive Behavioural Divergence following Colonisation of the Freshwater Environment in Threespine Sticklebacks

    PubMed Central

    Di-Poi, Carole; Lacasse, Jennyfer; Rogers, Sean M.; Aubin-Horth, Nadia

    2014-01-01

    Colonisation of novel environments means facing new ecological challenges often resulting in the evolution of striking divergence in phenotypes. However, little is known about behavioural divergence following colonisation, despite the predicted importance of the role of behavioural phenotype-environment associations in adaptive divergence. We studied the threespine stickleback (Gasterosteus aculeatus), a model system for postglacial colonisation of freshwater habitats largely differing in ecological conditions from the ones faced by the descendants of the marine ancestor. We found that common-environment reared freshwater juveniles were less social, more active and more aggressive than their marine counterparts. This behavioural divergence could represent the result of natural selection that acted on individuals following freshwater colonisation, with predation as a key selection agent. Alternatively, the behavioural profile of freshwater juveniles could represent the characteristics of individuals that preferentially invaded freshwater after the glacial retreat, drawn from the standing variation present in the marine population. PMID:24914554

  8. The response of the central Arctic Ocean stratification to freshwater perturbations

    NASA Astrophysics Data System (ADS)

    Pemberton, P.; Nilsson, J.

    2016-01-01

    Using a state-of-the-art coupled ice-ocean-circulation model, we perform a number of sensitivity experiments to examine how the central Arctic Ocean stratification responds to changes in river runoff and precipitation. The simulations yield marked changes in the cold halocline and the Arctic Atlantic layer. Increased precipitation yields a warming of the Atlantic layer, which primarily is an advective signal, propagated through the St. Anna Trough, reflecting air-sea heat flux changes over the Barents Sea. As the freshwater supply is increased, the anticyclonic Beaufort Gyre is weakened and a greater proportion of the Arctic Ocean freshwater is exported via the Fram Strait, with nearly compensating export decreases through the Canadian Arctic Archipelago. The corresponding reorganization of the freshwater pool appears to be controlled by advective processes, rather than by the local changes in the surface freshwater flux. A simple conceptual model of the Arctic Ocean, based on a geostrophically controlled discharge of the low-salinity water, is introduced and compared with the simulations. Key predictions of the conceptual model are that the halocline depth should decrease with increasing freshwater input and that the Arctic Ocean freshwater storage should increase proportionally to the square root of the freshwater input, which are in broad qualitative agreement with the sensitivity experiments. However, the model-simulated rate of increase of the freshwater storage is weaker, indicating that effects related to wind forcing and rerouting of the freshwater-transport pathways play an important role for the dynamics of the Arctic Ocean freshwater storage.

  9. Stability of the WSSV ORF94 VNTR genotype marker during passage in marine shrimp, freshwater crayfish and freshwater prawns.

    PubMed

    Gudkovs, Nicholas; Murwantoko, Murwantoko; Walker, Peter J

    2014-10-16

    The white spot syndrome virus (WSSV) genome contains 3 variable number tandem repeat (VNTR) regions, located in open reading frame (ORF) 75, ORF94 and ORF125, which have been employed for molecular epizootiological studies. A previous report suggested that the ORF 94 VNTR is highly unstable, varying in the number of tandem repeats during single passages from shrimp to other crustaceans. As such rapid variations would have profound implications for the interpretation of molecular epizootiological data, we re-examined the stability of the ORF94 VNTR. Two WSSV isolates with different ORF94 VNTR genotypes (TRS5 and TRS7) were obtained from disease outbreaks in farmed black tiger shrimp Penaeus monodon in Indonesia. High titre stocks of each virus were produced by injection in specific pathogen-free (SPF) Pacific white shrimp Litopenaeus vannamei with filtered infected tissue extracts, and the genotypes were confirmed. Each stock (macerated tissue) was then used to feed SPF Pacific white shrimp, freshwater crayfish (Cherax sp.) and freshwater prawns Macrobrachium rosenbergii through 3 successive passages involving alternative hosts at each level. Taqman real-time PCR was conducted on samples from each group to confirm infection and quantify viral genetic loads. ORF94 VNTR genotype analysis conducted on samples from each of the 43 passage groups indicated no variations in the VNTR number in either genotype TRS5 or genotype TRS7. This finding is contrary to the previous report and suggests that ORF94 VNTR are stable during multiple passages in these crustaceans. PMID:25320037

  10. 78 FR 24723 - Freshwater Crawfish Tail Meat From the People's Republic of China: Initiation of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-26

    ... Order: Freshwater Crawfish Tail Meat From the People's Republic of China, 62 FR 48218 (September 15... International Trade Administration Freshwater Crawfish Tail Meat From the People's Republic of China: Initiation... order on freshwater crawfish tail meat from the People's Republic of China (PRC), meets the...

  11. 77 FR 65667 - Freshwater Crawfish Tail Meat From the People's Republic of China: Initiation of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-30

    ... the People's Republic of China, 62 FR 48218 (September 15, 1997). \\2\\ See Freshwater Crawfish Tail... International Trade Administration Freshwater Crawfish Tail Meat From the People's Republic of China: Initiation... antidumping duty order on freshwater crawfish tail meat from the People's Republic of China (``PRC''),...

  12. 50 CFR 80.66 - What requirements apply to allocation of funds between marine and freshwater fisheries projects?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... funds between marine and freshwater fisheries projects? 80.66 Section 80.66 Wildlife and Fisheries... requirements apply to allocation of funds between marine and freshwater fisheries projects? The requirements of this section apply to allocation of funds between marine and freshwater fisheries projects. (a) When...

  13. 50 CFR 80.66 - What requirements apply to allocation of funds between marine and freshwater fisheries projects?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... funds between marine and freshwater fisheries projects? 80.66 Section 80.66 Wildlife and Fisheries... requirements apply to allocation of funds between marine and freshwater fisheries projects? The requirements of this section apply to allocation of funds between marine and freshwater fisheries projects. (a) When...

  14. 50 CFR 80.66 - What requirements apply to allocation of funds between marine and freshwater fisheries projects?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... funds between marine and freshwater fisheries projects? 80.66 Section 80.66 Wildlife and Fisheries... requirements apply to allocation of funds between marine and freshwater fisheries projects? The requirements of this section apply to allocation of funds between marine and freshwater fisheries projects. (a) When...

  15. 50 CFR 80.66 - What requirements apply to allocation of funds between marine and freshwater fisheries projects?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... funds between marine and freshwater fisheries projects? 80.66 Section 80.66 Wildlife and Fisheries... requirements apply to allocation of funds between marine and freshwater fisheries projects? The requirements of this section apply to allocation of funds between marine and freshwater fisheries projects. (a) When...

  16. Resolution in Electromagnetic Prospecting

    NASA Astrophysics Data System (ADS)

    Aldridge, D. F.; Bartel, L. C.; Knox, H. A.; Schramm, K. A.

    2014-12-01

    Low-frequency electromagnetic (EM) signals are commonly used in geophysical exploration of the shallow subsurface. Sensitivity to conductivity implies they are particularly useful for inferring fluid content of porous media. However, low-frequency EM wavefields are diffusive, and have significantly larger wavelengths compared to seismic signals of equal frequency. The wavelength of a 30 Hz sinusoid propagating with seismic velocity 3000 m/s is 100 m, whereas an analogous EM signal diffusing through a conductive body of 0.1 S/m (clayey shale) has wavelength 1825 m. The larger wavelength has implications for resolution of the EM prospecting method. We are investigating resolving power of the EM method via theoretical and numerical experiments. Normal incidence plane wave reflection/transmission by a thin geologic bed is amenable to analytic solution. Responses are calculated for beds that are conductive or resistive relative to the host rock. Preliminary results indicate the classic seismic resolution/detection limit of bed thickness ~1/8 wavelength is not achieved. EM responses for point or line current sources recorded by general acquisition geometries are calculated with a 3D finite-difference algorithm. These exhibit greater variability which may allow inference of bed thickness. We also examine composite responses of two point scatterers with separation when illuminated by an incident EM field. This is analogous to the Rayleigh resolution problem of estimating angular separation between two light sources. The First Born Approximation implies that perturbations in permittivity, permeability, and conductivity have different scattering patterns, which may be indicators of EM medium properties. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  17. Multi-Model approach to reconstruct the Mediterranean Freshwater Evolution

    NASA Astrophysics Data System (ADS)

    Simon, Dirk; Marzocchi, Alice; Flecker, Rachel; Lunt, Dan; Hilgen, Frits; Meijer, Paul

    2016-04-01

    Today the Mediterranean Sea is isolated from the global ocean by the Strait of Gibraltar. This restricted nature causes the Mediterranean basin to react more sensitively to climatic and tectonic related phenomena than the global ocean. Not just eustatic sea-level and regional river run-off, but also gateway tectonics and connectivity between sub-basins are leaving an enhanced fingerprint in its geological record. To understand its evolution, it is crucial to understand how these different effects are coupled. The Miocene-Pliocene sedimentary record of the Mediterranean shows alternations in composition and colour and has been astronomically tuned. Around the Miocene-Pliocene Boundary the most extreme changes occur in the Mediterranean Sea. About 6% of the salt in the global ocean deposited in the Mediterranean Region, forming an approximately 2 km thick salt layer, which is still present today. This extreme event is named the Messinian Salinity Crisis (MSC, 5.97-5.33 Ma). The gateway and climate evolution is not well constrained for this time, which makes it difficult to distinguish which of the above mentioned drivers might have triggered the MSC. We, therefore, decided to tackle this problem via a multi-model approach: (1) We calculate the Mediterranean freshwater evolution via 30 atmosphere-ocean-vegetation simulations (using HadCM3L), to which we fitted to a function, using a regression model. This allows us to directly relate the orbital curves to evaporation, precipitation and run off. The resulting freshwater evolution can be directly correlated to other sedimentary and proxy records in the late Miocene. (2) By feeding the new freshwater evolution curve into a box/budget model we can predict the salinity and strontium evolution of the Mediterranean for a certain Atlantic-Mediterranean gateway. (3) By comparing these results to the known salinity thresholds of gypsum and halite saturation of sea water, but also to the late Miocene Mediterranean strontium

  18. Can DNA barcoding accurately discriminate megadiverse Neotropical freshwater fish fauna?

    PubMed Central

    2013-01-01

    Background The megadiverse Neotropical freshwater ichthyofauna is the richest in the world with approximately 6,000 recognized species. Interestingly, they are distributed among only 17 orders, and almost 80% of them belong to only three orders: Characiformes, Siluriformes and Perciformes. Moreover, evidence based on molecular data has shown that most of the diversification of the Neotropical ichthyofauna occurred recently. These characteristics make the taxonomy and identification of this fauna a great challenge, even when using molecular approaches. In this context, the present study aimed to test the effectiveness of the barcoding methodology (COI gene) to identify the mega diverse freshwater fish fauna from the Neotropical region. For this purpose, 254 species of fishes were analyzed from the Upper Parana River basin, an area representative of the larger Neotropical region. Results Of the 254 species analyzed, 252 were correctly identified by their barcode sequences (99.2%). The main K2P intra- and inter-specific genetic divergence values (0.3% and 6.8%, respectively) were relatively low compared with similar values reported in the literature, reflecting the higher number of closely related species belonging to a few higher taxa and their recent radiation. Moreover, for 84 pairs of species that showed low levels of genetic divergence (<2%), application of a complementary character-based nucleotide diagnostic approach proved useful in discriminating them. Additionally, 14 species displayed high intra-specific genetic divergence (>2%), pointing to at least 23 strong candidates for new species. Conclusions Our study is the first to examine a large number of freshwater fish species from the Neotropical area, including a large number of closely related species. The results confirmed the efficacy of the barcoding methodology to identify a recently radiated, megadiverse fauna, discriminating 99.2% of the analyzed species. The power of the barcode sequences to identify

  19. Size fractionated characterization of freshwater organic matter fluorescence

    NASA Astrophysics Data System (ADS)

    Baker, A.; Lead, J.; Elliott, S.; Demomi, A.; Liu, R.; Seredynska-Sobecka, B.; Hudson, N. J.

    2006-12-01

    We employ a range of optical (fluorescence, absorbance) techniques to freshwater organic matter, focusing on samples from urban catchments and using both traditional (filtration, cross flow ultrafiltration) and novel (split cell thin flow (SPLITT)) fractionation techniques to investigate the fluorescence characteristics of both dissolved and colloidal organic matter and to probe different fractions of the size range. We find: (1) As with previous studies, urban freshwaters have high tryptophan-like fluorescence in comparison to humic-like fluorescence. (2) After conventional filtration, our samples demonstrate that humic-like fluorescence is predominantly within the <25 nm fraction and pH dependent, suggesting that it is predominantly `dissolved'. Tryptophan-like fluorescence is associated with either dissolved, colloidal and particulate fractions, and is less pH dependent, depending on the sample, suggesting a variety of sources that are known to include microbial and biological cells and their exudates and the products of decomposition and feeding. (3) When the thermal quenching of fluorescence is investigated at different filter fractions, humic-like fluorescence quenching does not vary with filter fraction, whereas tryptophan-like fluorescence quenching exhibits a size dependency. This confirms at least two sources of tryptophan-like fluorescence that have different sizes and different thermal quenching properties. (4) SPLITT also shows that tryptophan-like fluorescence intensity is found mainly in the particulate material and is not pH dependent, while humic-like fluorescence intensities are dependent on pH but not on size. However, humic-like fluorescence intensity normalised to absorbance, related to fluorescence efficiency and molar mass, varies with size in the SPLITT samples. (5) Cross flow ultrafiltration confirms that, compared with tryptophan standards, freshwater tryptophan-like fluorescence is not dissolved and `free'. However, it is related to the

  20. Pesticide toxicity index for freshwater aquatic organisms, 2nd edition

    USGS Publications Warehouse

    Munn, Mark D.; Gilliom, Robert J.; Moran, Patrick W.; Nowell, Lisa H.

    2006-01-01

    The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is designed to assess current water-quality conditions, changes in water quality over time, and the effects of natural and human factors on water quality for the Nation's streams and ground-water resources. For streams, one of the most difficult parts of the assessment is to link chemical conditions to effects on aquatic biota, particularly for pesticides, which tend to occur in streams as complex mixtures with strong seasonal patterns. A Pesticide Toxicity Index (PTI) was developed that combines pesticide exposure of aquatic biota (measured concentrations of pesticides in stream water) with acute toxicity estimates (standard endpoints from laboratory bioassays) to produce a single index value for a sample or site. The development of the PTI was limited to pesticide compounds routinely measured in NAWQA studies and to toxicity data readily available from existing databases. Qualifying toxicity data were found for one or more types of test organisms for 124 of the 185 pesticide compounds measured in NAWQA samples, but with a wide range of available bioassays per compound (1 to 232). In the databases examined, there were a total of 3,669 bioassays for the 124 compounds, including 398 48-hour EC50 values (concentration at which 50 percent of test organisms exhibit a sublethal response) for freshwater cladocerans, 699 96-hour LC50 values (concentration lethal to 50 percent of test organisms) for freshwater benthic invertebrates, and 2,572 96-hour LC50 values for freshwater fish. The PTI for a particular sample is the sum of toxicity quotients (measured concentration divided by the median toxicity concentration from bioassays) for each detected pesticide, and thus, is based on the concentration addition model of pesticide toxicity. The PTI can be calculated for specific groups of pesticides and for specific taxonomic groups. Although the PTI does not determine whether water in a sample is