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Sample records for survey chesapeake bay

  1. Chesapeake Bay Bald Eagle Nesting Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Chesapeake Bay population of breeding bald eagles increased dramatically in 1981 in not only the number of breeding pairs but in the number of nests hatching...

  2. Identifying Fossil Shell Resources via Geophysical Surveys: Chesapeake Bay Region, Virginia

    Science.gov (United States)

    2016-05-01

    ER D C/ CH L TR -1 6- 4 Chesapeake Fossil Shell Survey Identifying Fossil Shell Resources via Geophysical Surveys: Chesapeake Bay Region...other technical reports published by ERDC, visit the ERDC online library at http://acwc.sdp.sirsi.net/client/default. Chesapeake Fossil Shell...Survey ERDC/CHL TR-16-4 May 2016 Identifying Fossil Shell Resources via Geophysical Surveys: Chesapeake Bay Region, Virginia Heidi M. Wadman and Jesse

  3. 1971 American Eagle Nest Survey of the Chesapeake Bay Region.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Data refers to the 1971 nesting season for the Bald Eagle in the Chesapeake area to include Virginia and Maryland. In general, the Chesapeake Bay region nesting...

  4. Chesapeake Bay Bald Eagle Breeding Survey 1978

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In its second year, the Chesapeake Region Eagle Group (CREG) obtained the data for this report. CREG consists of representatives of the U.S. Fish and Wildlife...

  5. U.S. Geological Survey Chesapeake Bay Studies: Scientific Solutions for a Healthy Bay and Watershed

    Science.gov (United States)

    Phillips, Scott

    2006-01-01

    The U.S. Geological Survey (USGS), the science agency for the Department of Interior (DOI), has the critical role of providing objective science to document and understand ecosystem change in the Chesapeake Bay and its watershed. The human population in the Bay watershed, which grew from 8.1 million in 1950 to almost 16 million in 2000, has resulted in degraded water quality, loss of habitat, and declines in fish and bird populations. USGS scientists are leaders in understanding cause and effect of human activities and natural changes on water quality and the health of the ecosystem. The USGS interacts with resource managers and policy makers to use the science to adapt approaches for implementation, and assess effectiveness of, management actions for ecosystem conservation, restoration, and sustainability.

  6. Chesapeake Bay Tributary Strategies

    Science.gov (United States)

    Chesapeake Bay Tributary Strategies were developed by the seven watershed jurisdictions and outlined the river basin-specific implementation activities to reduce nutrient and sediment pollutant loads from point and nonpoint sources.

  7. 1972 American Eagle Nest Survey of the Chesapeake Bay Region.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Data refers to the 1972 nesting season for the Bald Eagle in the Chesapeake area to include Virginia and Maryland. The 1972 nesting season for the Bald Eagle in the...

  8. 1970 American Eagle Nest Survey of the Chesapeake Bay Region.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Data refers to the 1970 nesting season for the Bald Eagle in the Chesapeake area to include Virginia and Maryland. The 1970 results are most disappointing since...

  9. 1982 Bald Eagle Nest Survey, Chesapeake Bay Region.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Data refers to the 1982 nesting season for the Bald Eagle in the Chesapeake area to include Virginia, Maryland and Delaware. For the third year in succession we have...

  10. Hydrogeomorphic Regions in the Chesapeake Bay Watershed.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Generalized lithology (rock type) and physiography based on geologic formations were used to characterize hydrgeomorphic regions (HGMR) within the Chesapeake Bay...

  11. U.S. Geological Survey Science—Improving the value of the Chesapeake Bay watershed

    Science.gov (United States)

    Phillips, Scott W.; Hyer, Kenneth; Goldbaum, Elizabeth

    2017-05-05

    IntroductionCongress directed the Federal Government to work with States to restore the Nation’s largest estuary.Chesapeake Bay restoration provides important economic and ecological benefits:18 million people live and work in the Bay watershed and enjoy its benefits.3,600 types of fish, wildlife, and plants underpin the economic value of the Bay ecosystem.Poor water quality and habitat loss threaten restoration and negatively impact the economy.10 Goals to meet by 2025 through the Chesapeake Bay Program, a voluntary partnership.

  12. Temperature and salinity profile data collected from CTD casts by NOAA Ship BAY HYDROGRAPHER in the Chesapeake Bay during survey operations along the NE US coast from 2006-01-05 to 2006-08-28 (NCEI Accession 0014614)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pressure, salinity, and temperature data were collected from CTD casts from the NOAA Survey Vessel BAY HYDROGRAPHER. Data were collected in the Chesapeake Bay from...

  13. Chesapeake Bay Program Water Quality Database

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Chesapeake Information Management System (CIMS), designed in 1996, is an integrated, accessible information management system for the Chesapeake Bay Region....

  14. Chesapeake Bay: Introduction to an Ecosystem.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC.

    The Chesapeake Bay is the largest estuary in the contiguous United States. The Bay and its tidal tributaries make up the Chesapeake Bay ecosystem. This document, which focuses of various aspects of this ecosystem, is divided into four major parts. The first part traces the geologic history of the Bay, describes the overall physical structure of…

  15. Tumors in brown bullheads in the Chesapeake Bay watershed: analysis of survey data from 1992 through 2006.

    Science.gov (United States)

    Pikney, Alfred E; Harshbarger, John C; Rutter, Michael A

    2009-06-01

    Liver and skin tumor prevalences in brown bullheads Ameiurus nebulosus have been used in the North American Great Lakes to designate highly contaminated areas of concern and monitor their recovery. Here we interpret the results of six surveys conducted in the Chesapeake Bay watershed between 1992 and 2006, with data for 647 fish. The objective has been to develop an adequate database to critically evaluate the use of tumor prevalence as a habitat quality indicator within the watershed. Surveys featured randomized fish collection; recording of sex, length, weight, and age; and histopathology of all livers and all raised skin lesions. The Bayes information criterion was used to analyze all possible combinations of age, gender, length, and weight as covariates for logistic regression. Length and gender were the covariates that best described liver tumor prevalence. There were no covariates in the model for skin tumor prevalence. In some surveys, biomarkers, such as biliary polynuclear aromatic hydrocarbon (PAH)-like metabolites, hepatic cytochrome P450 activity, and hepatic DNA adducts, were used with sediment and tissue chemistry data to evaluate classes of chemicals as likely contributors to tumor prevalence. We highlight two surveys of the Anacostia River, Washington, D.C. (average = 55% liver tumors, 23% skin tumors), where sediment PAHs, biliary PAH-like metabolites, and hepatic DNA adducts were high, suggesting that PAHs play a major role. We show that logistic regression is an appropriate procedure for comparing "contaminated" versus "reference" locations, and we evaluate the utility of tumor surveys as an environmental indicator for the Chesapeake Bay watershed.

  16. Deriving Chesapeake Bay Water Quality Standards

    Science.gov (United States)

    Tango, Peter J.; Batiuk, Richard A.

    2013-01-01

    Achieving and maintaining the water quality conditions necessary to protect the aquatic living resources of the Chesapeake Bay and its tidal tributaries has required a foundation of quantifiable water quality criteria. Quantitative criteria serve as a critical basis for assessing the attainment of designated uses and measuring progress toward meeting water quality goals of the Chesapeake Bay Program partnership. In 1987, the Chesapeake Bay Program partnership committed to defining the water quality conditions necessary to protect aquatic living resources. Under section 303(c) of the Clean Water Act, States and authorized tribes have the primary responsibility for adopting water quality standards into law or regulation. The Chesapeake Bay Program partnership worked with U.S. Environmental Protection Agency to develop and publish a guidance framework of ambient water quality criteria with designated uses and assessment procedures for dissolved oxygen, water clarity, and chlorophyll a for Chesapeake Bay and its tidal tributaries in 2003. This article reviews the derivation of the water quality criteria, criteria assessment protocols, designated use boundaries, and their refinements published in six addendum documents since 2003 and successfully adopted into each jurisdiction's water quality standards used in developing the Chesapeake Bay Total Maximum Daily Load.

  17. Modeling nitrogen cycling in forested watersheds of Chesapeake Bay

    Energy Technology Data Exchange (ETDEWEB)

    Hunsaker, C.T.; Garten, C.T.; Mulholland, P.J.

    1995-03-01

    The Chesapeake Bay Agreement calls for a 40% reduction of controllable phosphorus and nitrogen to the tidal Bay by the year 2000. To accomplish this goal the Chesapeake Bay Program needs accurate estimates of nutrient loadings, including atmospheric deposition, from various land uses. The literature was reviewed on forest nitrogen pools and fluxes, and nitrogen data from research catchments in the Chesapeake Basin were identified. The structure of a nitrogen module for forests is recommended for the Chesapeake Bay Watershed Model along with the possible functional forms for fluxes.

  18. RES2DINV Format Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 8, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  19. Processed Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 7, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  20. Raw and Modified Raw Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 6, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  1. RES2DINV Format Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 7, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  2. Processed Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 8, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  3. Raw and Modified Raw Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 7, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  4. Processed Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 7, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  5. Raw and Modified Raw Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 6, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  6. Processed Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 6, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  7. RES2DINV Format Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 7, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  8. Raw and Modified Raw Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 7, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  9. Processed Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 6, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  10. Processed Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 8, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  11. Raw and Modified Raw Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 8, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  12. Raw and Modified Raw Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 8, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  13. RES2DINV Format Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 8, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  14. 33 CFR 334.170 - Chesapeake Bay, in the vicinity of Chesapeake Beach, Md.; firing range, Naval Research Laboratory.

    Science.gov (United States)

    2010-07-01

    ... of Chesapeake Beach, Md.; firing range, Naval Research Laboratory. 334.170 Section 334.170 Navigation... RESTRICTED AREA REGULATIONS § 334.170 Chesapeake Bay, in the vicinity of Chesapeake Beach, Md.; firing range... on the west by the shore of Chesapeake Bay. (2) Area B. The sector of a circle bounded by radii of...

  15. Endocrine disrupter - estradiol - in Chesapeake Bay tributaries

    Energy Technology Data Exchange (ETDEWEB)

    Dorabawila, Nelum [University of Maryland Eastern Shore, Princess Anne, MD 21853 (United States); Gupta, Gian [University of Maryland Eastern Shore, Princess Anne, MD 21853 (United States)]. E-mail: gcgupta@umes.edu

    2005-04-11

    Exogenous chemicals that interfere with natural hormonal functions are considered endocrine disrupting chemicals (EDCs). Estradiol (17{beta}-estradiol or E2) is the most potent of all xenoestrogens. Induction of vitellogenin (VTG) production in male fish occurs at E2 concentrations as low as 1 ng l{sup -1}. E2 reaches aquatic systems mainly through sewage and animal waste disposal. Surface water samples from ponds, rivers (Wicomico, Manokin and Pocomoke), sewage treatment plants (STPs), and coastal bays (Assawoman, Monie, Chincoteague, and Tangier Sound - Chesapeake Bay) on the Eastern Shore of Maryland were analyzed for E2 using enzyme linked immuno-sorbent assay (ELISA). E2 concentrations in river waters varied between 1.9 and 6.0 ng l{sup -1}. Highest E2 concentrations in river waters were observed immediately downstream of STPs. E2 concentrations in all the coastal bays tested were 2.3-3.2 ng l{sup -1}.

  16. Defining a data management strategy for USGS Chesapeake Bay studies

    Science.gov (United States)

    Ladino, Cassandra

    2013-01-01

    The mission of U.S. Geological Survey’s (USGS) Chesapeake Bay studies is to provide integrated science for improved understanding and management of the Chesapeake Bay ecosystem. Collective USGS efforts in the Chesapeake Bay watershed began in the 1980s, and by the mid-1990s the USGS adopted the watershed as one of its national place-based study areas. Great focus and effort by the USGS have been directed toward Chesapeake Bay studies for almost three decades. The USGS plays a key role in using “ecosystem-based adaptive management, which will provide science to improve the efficiency and accountability of Chesapeake Bay Program activities” (Phillips, 2011). Each year USGS Chesapeake Bay studies produce published research, monitoring data, and models addressing aspects of bay restoration such as, but not limited to, fish health, water quality, land-cover change, and habitat loss. The USGS is responsible for collaborating and sharing this information with other Federal agencies and partners as described under the President’s Executive Order 13508—Strategy for Protecting and Restoring the Chesapeake Bay Watershed signed by President Obama in 2009. Historically, the USGS Chesapeake Bay studies have relied on national USGS databases to store only major nationally available sources of data such as streamflow and water-quality data collected through local monitoring programs and projects, leaving a multitude of other important project data out of the data management process. This practice has led to inefficient methods of finding Chesapeake Bay studies data and underutilization of data resources. Data management by definition is “the business functions that develop and execute plans, policies, practices and projects that acquire, control, protect, deliver and enhance the value of data and information.” (Mosley, 2008a). In other words, data management is a way to preserve, integrate, and share data to address the needs of the Chesapeake Bay studies to better

  17. Black ducks and their Chesapeake Bay habitats : proceedings of a symposium

    Science.gov (United States)

    Perry, Matthew C.

    2002-01-01

    The symposium 'Black Ducks and Their Chesapeake Bay Habitats,' held October 4, 2000, provided a forum for scientists to share research about the American black duck (Anas rubripes), an important breeding and wintering waterfowl species dependent upon the Chesapeake Bay habitats. American black ducks have declined significantly in the last 50 years and continue to be a species of management concern. The symposium, sponsored by the Wildfowl Trust of North America and the U.S. Geological Survey, highlighted papers and posters on a range of topics, from the traditional concerns of hunting, habitat, and hybridization to the more recent concerns of human disturbance and neophobia. Other presentations provided a historical perspective of black duck management. The direction that black duck conservation initiatives could and/or should take in the future was also discussed. As populations of humans in the Chesapeake Bay region continue to increase, we can expect that these subjects will receive increased discussion in the future.

  18. Color-hillshade relief GeoTIFF image of the Potomac River/Chesapeake Bay Area (CLRHSHD_POTO_GEO.TIF, Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  19. RES2DINV Format Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 6, 2006 on USGS Cruise 06018

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  20. Color-hillshade relief GeoTIFF image of the Potomac River/Chesapeake Bay Area (CLRHSHD_POTO_GEO.TIF, Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  1. SEG-Y Formatted Seismic-Reflection Profile Data Collected in the Potomac River/Chesapeake Bay from Sept. 6, 2006 to Sept. 8, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  2. Ship Trackline Along Which Continuous Resistivity Profile (CRP) Data was Collected in the Potomac River/Chesapeake Bay on Sept. 8, 2006 (RESGPSLNS_JD251.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  3. RES2DINV Format Continuous Resistivity Profile Data Collected in the Potomac River/Chesapeake Bay on Sept. 6, 2006 on USGS Cruise 06018

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  4. Ship Trackline Along Which Continuous Resistivity Profile (CRP) Data was Collected in the Potomac River/Chesapeake Bay on Sept. 8, 2006 (RESGPSLNS_JD251.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  5. Color-hillshade relief GeoTIFF image of the Potomac River/Chesapeake Bay Area (CLRHSHD_POTO.TIF, UTM, Zone 18, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  6. SEG-Y Formatted Seismic-Reflection Profile Data Collected in the Potomac River/Chesapeake Bay from Sept. 6, 2006 to Sept. 8, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  7. Color-hillshade relief GeoTIFF image of the Potomac River/Chesapeake Bay Area (CLRHSHD_POTO.TIF, UTM, Zone 18, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  8. CLRHSHD_POTO_GEO.TIF: Color-hillshade relief GeoTIFF image of the Potomac River/Chesapeake Bay Area (Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  9. CLRHSHD_POTO.TIF: Color-hillshade relief GeoTIFF image of the Potomac River/Chesapeake Bay Area (UTM, Zone 18, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  10. DEVELOP Chesapeake Bay Watershed Hydrology - UAV Sensor Web

    Science.gov (United States)

    Holley, S. D.; Baruah, A.

    2008-12-01

    The Chesapeake Bay is the largest estuary in the United States, with a watershed extending through six states and the nation's capital. Urbanization and agriculture practices have led to an excess runoff of nutrients and sediment into the bay. Nutrients and sediment loading stimulate the growth of algal blooms associated with various problems including localized dissolved oxygen deficiencies, toxic algal blooms and death of marine life. The Chesapeake Bay Program, among other stakeholder organizations, contributes greatly to the restoration efforts of the Chesapeake Bay. These stakeholders contribute in many ways such as monitoring the water quality, leading clean-up projects, and actively restoring native habitats. The first stage of the DEVELOP Chesapeake Bay Coastal Management project, relating to water quality, contributed to the restoration efforts by introducing NASA satellite-based water quality data products to the stakeholders as a complement to their current monitoring methods. The second stage, to be initiated in the fall 2008 internship term, will focus on the impacts of land cover variability within the Chesapeake Bay Watershed. Multiple student led discussions with members of the Land Cover team at the Chesapeake Bay Program Office in the DEVELOP GSFC 2008 summer term uncovered the need for remote sensing data for hydrological mapping in the watershed. The Chesapeake Bay Program expressed in repeated discussions on Land Cover mapping that significant portions of upper river areas, streams, and the land directly interfacing those waters are not accurately depicted in the watershed model. Without such hydrological mapping correlated with land cover data the model will not be useful in depicting source areas of nutrient loading which has an ecological and economic impact in and around the Chesapeake Bay. The fall 2008 DEVELOP team will examine the use of UAV flown sensors in connection with in-situ and Earth Observation satellite data. To maximize the

  11. Chesapeake Bay Low Freshwater Inflow Study. Biota Assessment. Phase I. Appendices.

    Science.gov (United States)

    1980-08-01

    in lower Bay. 11. Macrofauna distribution with respect to sediment size. 12. Benthic infauna and sediment chemistry survey. 13. Plankton response to...transparent, gelatinous animal, roughly pear-shaped, with four oral lobes. Adults have no tentacles. The organism swims by means of its 8 rows of comb... planktonic rotifer of the family Brachionidae. Range: Brachionis calyciflorus is found worldwide in temperate fresh and oligohaline areas. In Chesapeake Bay

  12. Chesapeake Bay Impact Structure Deep Drilling Project Completes Coring

    Directory of Open Access Journals (Sweden)

    the Scientific Staff of the Chesapeake Bay Impact Structure Deep Drilling Project

    2006-09-01

    Full Text Available The Chesapeake Bay Impact Structure Deep Drilling Project (CBIS Project completed its coring operations during September–December 2005 and April–May 2006. Cores were collected continuously to a total depth of 1766 m. The recovered section consists of 1322 m of impactites beneath 444 m of post-impact continental shelf sediments.The CBIS Project is a joint venture of the International Continental Scientifi c Drilling Program (ICDP and the U.S. Geological Survey (USGS. Project activities began with a planning workshop in September 2003 attended by sixtythree scientists from ten countries. Field operations began with site preparation in July 2005, and coring began in September 2005. Drilling, Observation and Sampling of theEarth’s Continental Crust (DOSECC was the general contractor for the drilling operations throughout 2005.

  13. Deep drilling in the Chesapeake Bay impact structure - An overview

    Science.gov (United States)

    Gohn, G.S.; Koeberl, C.; Miller, K.G.; Reimold, W.U.

    2009-01-01

    The late Eocene Chesapeake Bay impact structure lies buried at moderate depths below Chesapeake Bay and surrounding landmasses in southeastern Virginia, USA. Numerous characteristics made this impact structure an inviting target for scientific drilling, including the location of the impact on the Eocene continental shelf, its threelayer target structure, its large size (??85 km diameter), its status as the source of the North American tektite strewn field, its temporal association with other late Eocene terrestrial impacts, its documented effects on the regional groundwater system, and its previously unstudied effects on the deep microbial biosphere. The Chesapeake Bay Impact Structure Deep Drilling Project was designed to drill a deep, continuously cored test hole into the central part of the structure. A project workshop, funding proposals, and the acceptance of those proposals occurred during 2003-2005. Initial drilling funds were provided by the International Continental Scientific Drilling Program (ICDP) and the U.S. Geological Survey (USGS). Supplementary funds were provided by the National Aeronautics and Space Administration (NASA) Science Mission Directorate, ICDP, and USGS. Field operations were conducted at Eyreville Farm, Northampton County, Virginia, by Drilling, Observation, and Sampling of the Earth's Continental Crust (DOSECC) and the project staff during September-December 2005, resulting in two continuously cored, deep holes. The USGS and Rutgers University cored a shallow hole to 140 m in April-May 2006 to complete the recovered section from land surface to 1766 m depth. The recovered section consists of 1322 m of crater materials and 444 m of overlying postimpact Eocene to Pleistocene sediments. The crater section consists of, from base to top: basement-derived blocks of crystalline rocks (215 m); a section of suevite, impact melt rock, lithic impact breccia, and cataclasites (154 m); a thin interval of quartz sand and lithic blocks (26 m); a

  14. Chesapeake Bay Future Conditions Report. Volume 6. Water Quality

    Science.gov (United States)

    1977-12-01

    and paper industries for example, lingosulfates or pulp wastes can be synthesized to produce artificial vanilla flavoring and other valuable acetic...Plants in the Chesapeake Bay Area. Ozone is a blue, pungent smelling, unstable gas existing as an oxidized form of oxygen. Disinfec- tion by ozonation is

  15. Numerical Modeling of Storm Surges in Chesapeake Bay

    Science.gov (United States)

    2008-01-01

    bathymetry grid was developed from several data sources, including the National Ocean Service (NOS) Digital Navigation Charts ( DNC ), bathymetry data from...of Virginia and Maryland coasts. This grid was refined in Chesapeake Bay (Figure 5) using the NOS/ DNC data, a composite dataset from VIMS, GEODAS

  16. Chesapeake Bay Low Freshwater Inflow Study. Appendix E. Biota.

    Science.gov (United States)

    1984-09-01

    Freshwater Inflow Study, results of testing on the Chesapeake b~ay Hydraulic - Model were used to assess the effects on the Bay of projected future depressed ...variety of food items. radpoles are usually regarded as vegetarians , but are occasionally carnivorous, and sometimes cannibalistic. Salamander larvae, and...it is to the estuarine environment, feeds mainly on crustaceans and molluscs. With the exception of Chelonia mydas, which is exclusively vegetarian

  17. BOOK REVIEW OF "CHESAPEAKE BAY BLUES: SCIENCE, POLITICS, AND THE STRUGGLE TO SAVE THE BAY"

    Science.gov (United States)

    This is a book review of "Chesapeake Bay Blues: Science, Politics, and the Struggle to Save the Bay". This book is very well written and provides an easily understandable description of the political challenges faced by those proposing new or more stringent environmental regulat...

  18. Temporal and spatial patterns of zooplankton in the Chesapeake Bay turbidity maximum

    National Research Council Canada - National Science Library

    M. R. Roman; D. V. Holliday; L. P. Sanford

    2001-01-01

    We measured the distribution of hydrographic parameters, currents, phytoplankton fluorescence, suspended sediments and zooplankton in axial transects through the Chesapeake Bay estuarine turbidity maximum (ETM) seasonally...

  19. Chesapeake Bay impact structure: A blast from the past

    Science.gov (United States)

    Powars, David S.; Edwards, Lucy E.; Gohn, Gregory S.; Horton, Jr., J. Wright

    2015-10-28

    About 35 million years ago, a 2-mile-wide meteorite smashed into Earth in what is now the lower Chesapeake Bay in Virginia. The oceanic impact vaporized, melted, fractured, and displaced rocks and sediments and sent billions of tons of water, sediments, and rocks into the air. Glassy particles of solidified melt rock rained down as far away as Texas and the Caribbean. Large tsunamis affected most of the North Atlantic basin. The resulting impact structure is more than 53 miles wide and has a 23-mile-wide, filled central crater surrounded by collapsed sediments. Now buried by hundreds of feet of younger sediments, the Chesapeake Bay impact structure is among the 20 largest known impact structures on Earth.

  20. Preliminary estimates of residence times and apparent ages of ground water in the Chesapeake Bay watershed, and water-quality data from a survey of springs

    Science.gov (United States)

    Focazio, Michael J.; Plummer, L. Neil; Bohlke, John K.; Busenberg, Eurybiades; Bachman, L. Joseph; Powars, David S.

    1998-01-01

    Knowledge of the residence times of the ground-water systems in Chesapeake Bay watershed helps resource managers anticipate potential delays between implementation of land-management practices and any improve-ments in river and estuary water quality. This report presents preliminary estimates of ground-water residence times and apparent ages of water in the shallow aquifers of the Chesapeake Bay watershed. A simple reservoir model, published data, and analyses of spring water were used to estimate residence times and apparent ages of ground-water discharge. Ranges of aquifer hydraulic characteristics throughout the Bay watershed were derived from published literature and were used to estimate ground-water residence times on the basis of a simple reservoir model. Simple combinations of rock type and physiographic province were used to delineate hydrogeomorphic regions (HGMR?s) for the study area. The HGMR?s are used to facilitate organization and display of the data and analyses. Illustrations depicting the relation of aquifer characteristics and associated residence times as a continuum for each HGMR were developed. In this way, the natural variation of aquifer characteristics can be seen graphically by use of data from selected representative studies. Water samples collected in September and November 1996, from 46 springs throughout the watershed were analyzed for chlorofluorocarbons (CFC?s) to estimate the apparent age of ground water. For comparison purposes, apparent ages of water from springs were calculated assuming piston flow. Additi-onal data are given to estimate apparent ages assuming an exponential distribution of ages in spring discharge. Additionally, results from previous studies of CFC-dating of ground water from other springs and wells in the watershed were compiled. The CFC data, and the data on major ions, nutrients, and nitrogen isotopes in the water collected from the 46 springs are included in this report. The apparent ages of water

  1. FY 2016 Grant Announcement: FY 2016 Technical Analysis and Programmatic Evaluation Support to the Chesapeake Bay Program Partnership

    Science.gov (United States)

    The U.S. Environmental Protection Agency’s Chesapeake Bay Program Office is announcing a Request for Proposals for applicants to provide the Chesapeake Bay Program partners with a proposal(s) for providing technical analysis and programmatic evaluation

  2. Chesapeake Bay subsidence monitored as wetlands loss continues

    Science.gov (United States)

    Nerem, R. S.; van Dam, T. M.; Schenewerk, M. S.

    Fragile wetland ecosystems, which support an abundance of wildlife, are being lost around the Chesapeake Bay at an alarming rate due to an increase in sea level. For example, one third of the total area of the Blackwater National Wildlife Refuge (Figure 1) (approximately 20 km2) was lost between 1938 and 1979 [Leatherman, 1992]. Approximately 4,100 km2 of the perimeter of the Chesapeake Bay are covered by wetlands of which 58% forested wetlands and 28% are salt marshes. It is likely that many factors are responsible for the wetlands loss, some that have global implications, and some that reflect local phenomena.Understanding the mechanisms responsible for wetlands deterioration and loss, however, has been impeded by the lack of adequate data including quantitative monitoring of the types and distribution of flora, Tthe boundaries of specific habitat types, and data on the spatial variations in sea level and land subsidence. This article focuses on the latter problem, which is to determine the relative roles of sea level rise and land subsidence in the region. Over the past four years, a small network of Global Positioning System (GPS) receivers have been installed near tide gauges in the Chesapeake Bay to help determine the cause of relative sea level rise in this region. These receivers are just beginning to yield results.

  3. Processed Continuous Resistivity Profile (CRP) Data Below the Sediment Water Interface From the Potomac River/Chesapeake Bay collected from Sept. 6, 2006 to Sept. 8, 2006 on USGS Cruise 06018 (MRG2006_ALLZYZ.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  4. Navigation and Bathymetry Points of Ship Position During Continuous Resistivity Profile Data Collection in the Potomac River/Chesapeake Bay on Sept. 6, 2006 on USGS Cruise 06018 (RESGPSPNTS_JD249.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  5. Point Shapefile of 500 Shot Interval Point Navigation For Seismic Data Collected in the Potomac River/Chesapeake Bay from Sept. 6, 2006 to Sept. 8, 2006 on USGS Cruise 06018 (SHOT500SORT_GEOG.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  6. Ship Trackline Along Which Continuous Resistivity Profile (CRP) Data was Collected in the Potomac River/Chesapeake Bay on Sept. 7, 2006 on USGS Cruise 06018 (RESGPSLNS_JD250.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  7. Point Shapefile of 100 Shot Interval Point Navigation For Seismic Data Collected in the Potomac River/Chesapeake Bay from Sept. 6, 2006 to Sept. 8, 2006 on USGS Cruise 06018 (SHOT100SORT_GEOG.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  8. Navigation and Bathymetry Points of Ship Position During Continuous Resistivity Profile Data Collection in the Potomac River/Chesapeake Bay on Sept. 6, 2006 on USGS Cruise 06018 (RESGPSPNTS_JD249.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  9. RESGPSPNTS_JD249.SHP: Navigation and Bathymetry Points of Ship Position During Continuous Resistivity Profile Data Collection in the Potomac River/Chesapeake Bay on Sept. 6, 2006 on USGS Cruise 06018

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  10. RESGPSLNS_JD250.SHP: Ship Trackline Along Which Continuous Resistivity Profile (CRP) Data was Collected in the Potomac River/Chesapeake Bay on Sept. 7, 2006 on USGS Cruise 06018

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  11. RESGPSPNTS_JD251.SHP: Navigation, Bathymetry and Temperature Point at the Ship Position During Continuous Resistivity Profile Data Collection in the Potomac River/Chesapeake Bay on Sept. 8, 2006 on USGS Cruise 06018

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  12. Seismic-Reflection Profile Data in JPEG Image Format Collected in the Potomac River/Chesapeake Bay from Sept. 6, 2006 to Sept. 8, 2006 on USGS Cruise 06018

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  13. ALLSHOTS_GEOG.SHP: Point Shapefile of All the Unique Seismic Shot Point Navigation Collected in the Potomac River/Chesapeake Bay from Sept. 6, 2006 to Sept. 8, 2006 on USGS Cruise 06018

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  14. RESGPSPNTS_JD250.SHP: Navigation, Bathymetry and Temperature Points at the Ship Position During Continuous Resistivity Profile Data Collection in the Potomac River/Chesapeake Bay on Sept. 7, 2006 on USGS Cruise 06018

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  15. RESGPSLNS_JD249.SHP: Ship Trackline along which Continuous Resistivity Profile Data was Collected in the Potomac River/Chesapeake Bay on Sept., 6, 2006 on USGS Cruise 06018

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  16. Shot Point Calibrated Trackline Navigation for Seismic Data Collected in the Potomac River/Chesapeake Bay from Sept. 6, 2006 to Sept. 8, 2006 (TRACK_ROUTE_CALIB_GEOG.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  17. Navigation, Bathymetry and Temperature Points at the Ship Position During Continuous Resistivity Profile Data Collection in the Potomac River/Chesapeake Bay on Sept. 7, 2006 on USGS Cruise 06018 (RESGPSPNTS_JD250.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  18. Point Shapefile of 100 Shot Interval Point Navigation For Seismic Data Collected in the Potomac River/Chesapeake Bay from Sept. 6, 2006 to Sept. 8, 2006 on USGS Cruise 06018 (SHOT100SORT_GEOG.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  19. Processed Continuous Resistivity Profile (CRP) Data Below the Sediment Water Interface From the Potomac River/Chesapeake Bay collected from Sept. 6, 2006 to Sept. 8, 2006 on USGS Cruise 06018 (MRG2006_ALLZYZ.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  20. Ship Trackline along which Continuous Resistivity Profile Data was Collected in the Potomac River/Chesapeake Bay on Sept., 6, 2006 on USGS Cruise 06018 (RESGPSLNS_JD249.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  1. Ship Trackline Along Which Continuous Resistivity Profile (CRP) Data was Collected in the Potomac River/Chesapeake Bay on Sept. 7, 2006 on USGS Cruise 06018 (RESGPSLNS_JD250.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  2. SHIP NAVIGATION: ANSI Text File of the Navigation and Bathymetry Recorded by the Ship's Differential Global Positioning System (DGPS) in the Potomac River/Chesapeake Bay from Sept. 6 to Sept. 8, 2006 - USGS Cruise 06018

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  3. Point Shapefile of 500 Shot Interval Point Navigation For Seismic Data Collected in the Potomac River/Chesapeake Bay from Sept. 6, 2006 to Sept. 8, 2006 on USGS Cruise 06018 (SHOT500SORT_GEOG.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  4. SHIP NAVIGATION: ANSI Text File of the Navigation and Bathymetry Recorded by the Ship's Differential Global Positioning System (DGPS) in the Potomac River/Chesapeake Bay from Sept. 6 to Sept. 8, 2006 - USGS Cruise 06018

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  5. SHOT100SORT_GEOG.SHP: Point Shapefile of 100 Shot Interval Point Navigation For Seismic Data Collected in the Potomac River/Chesapeake Bay from Sept. 6, 2006 to Sept. 8, 2006 on USGS Cruise 06018

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  6. TRACK_ROUTE_CALIB_GEOG.SHP: Shot Point Calibrated Trackline Navigation for Seismic Data Collected in the Potomac River/Chesapeake Bay from Sept. 6, 2006 to Sept. 8, 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  7. Point Shapefile of All the Unique Seismic Shot Point Navigation Collected in the Potomac River/Chesapeake Bay from Sept. 6, 2006 to Sept. 8, 2006 on USGS Cruise 06018 (ALLSHOTS_GEOG.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  8. Navigation, Bathymetry and Temperature Point at the Ship Position During Continuous Resistivity Profile Data Collection in the Potomac River/Chesapeake Bay on Sept. 8, 2006 on USGS Cruise 06018 (RESGPSPNTS_JD251.SHP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  9. Seismic-Reflection Profile Data in JPEG Image Format Collected in the Potomac River/Chesapeake Bay from Sept. 6, 2006 to Sept. 8, 2006 on USGS Cruise 06018

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In order to test hypotheses about groundwater flow under and into Chesapeake Bay, geophysical surveys were conducted by U.S. Geological Survey (USGS) scientists on...

  10. Field guide to fishes of the chesapeake bay

    CERN Document Server

    Murdy, Edward O.

    2013-01-01

    The only comprehensive field guide to the Chesapeake’s fishes, this book is an indispensable resource for both anglers and students of the Bay. Vivid illustrations by Val Kells complement the expertise of researchers Edward O. Murdy and John A. Musick. They describe fishes that inhabit waters ranging from low-salinity estuaries to the point where the Bay meets the Atlantic Ocean. Key features of this field guide include• full-color illustrations of more than 200 species• text that is presented adjacent to illustrations for easy reference• detailed descriptions of physical characteristics, range, occurrence in the Bay, reproduction, diet, and statistics from fisheries research• spot illustrations that highlight critical features of certain fish• illustrations of juveniles when they look different from adults• appendices that include identification keys Formatted as a compact field guide for students, scientists, researchers, and fishermen, Field Guide to Fishes of the Chesapeake Bay should be a ...

  11. 33 CFR 334.390 - Atlantic Ocean south of entrance to Chesapeake Bay; firing range.

    Science.gov (United States)

    2010-07-01

    ... to Chesapeake Bay; firing range. 334.390 Section 334.390 Navigation and Navigable Waters CORPS OF....390 Atlantic Ocean south of entrance to Chesapeake Bay; firing range. (a) The danger zone. A section... four (4) nautical miles. (3) Firing on the ranges will be suspended as long as any vessel is within...

  12. Factors affecting nutrient trends in major rivers of the Chesapeake Bay Watershed

    Science.gov (United States)

    Sprague, Lori A.; Langland, M.J.; Yochum, S.E.; Edwards, R.E.; Blomquist, J.D.; Phillips, S.W.; Shenk, G.W.; Preston, S.D.

    2000-01-01

    Trends in nutrient loads and flow-adjusted concentrations in the major rivers entering Chesapeake Bay were computed on the basis of water-quality data collected between 1985 and 1998 at 29 monitoring stations in the Susquehanna, Potomac, James, Rappahannock, York, Patuxent, and Choptank River Basins. Two computer models?the Chesapeake Bay Watershed Model (WSM) and the U.S. Geological Survey?s 'Spatially Referenced Regressions on Watershed attributes' (SPARROW) Model?were used to help explain the major factors affecting the trends. Results from WSM simulations provided information on temporal changes in contributions from major nutrient sources, and results from SPARROW model simulations provided spatial detail on the distribution of nutrient yields in these basins. Additional data on nutrient sources, basin characteristics, implementation of management practices, and ground-water inputs to surface water were analyzed to help explain the trends. The major factors affecting the trends were changes in nutrient sources and natural variations in streamflow. The dominant source of nitrogen and phosphorus from 1985 to 1998 in six of the seven tributary basins to Chesapeake Bay was determined to be agriculture. Because of the predominance of agricultural inputs, changes in agricultural nutrient sources such as manure and fertilizer, combined with decreases in agricultural acreage and implementation of best management practices (BMPs), had the greatest impact on the trends in flow-adjusted nutrient concentrations. Urban acreage and population, however, were noted to be increasing throughout the Chesapeake Bay Watershed, and as a result, delivered loads of nutrients from urban areas increased during the study period. Overall, agricultural nutrient management, in combination with load decreases from point sources due to facility upgrades and the phosphate detergent ban, led to downward trends in flow-adjusted nutrient concentrations atmany of the monitoring stations in the

  13. River Flow Control on the Phytoplankton Dynamics of Chesapeake Bay

    Institute of Scientific and Technical Information of China (English)

    YU Qingyun; WANG You; TANG Xuexi; LI Ming

    2013-01-01

    Recent observations support an emerging paradigm that climate variability dominates nutrient enrichment in costal ecosystems,which can explain seasonal and inter-annual variability of phytoplankton community composition,biomass (Chl-a),and primary production (PP).In this paper,we combined observation and modeling to investigate the regulation of phytoplankton dynamics in Chesapeake Bay.The year we chose is 1996 that has high river runoff and is usually called a ‘wet year’.A 3-D physical-biogeochemical model based on ROMS was developed to simulate the seasonal cycle and the regional distributions of phytoplankton biomass and primary production in Chesapeake Bay.Based on the model results,NO3 presents a strong contrast to the river nitrate load during spring and the highest concentration in the bay reaches around 80mmol N m3.Compared with the normal year,phytoplankton bloom in spring of 1996 appears in lower latitudes with a higher concentration.Quantitative comparison between the modeled and observed seasonal averaged dissolved inorganic nitrogen concentrations shows that the model produces reliable results.The correlation coefficient r2 for all quantities exceeds 0.95,and the skill parameter for the four seasons is all above 0.95.

  14. Verification of the Chesapeake Bay Model.

    Science.gov (United States)

    1981-12-01

    line of the five cups was about 0.045 ft above the bottom of the meter frame; 30 STEPPING MOTOR 200 STEPS REVOLUTION TRANSLATOR SRPPOT.E SELECTOR DIST...about 0.1 ft in the model, represented a horizontal width of about 100 ft in the prototype. The height of the meter cups , about 0.04 ft, represented...the entire bay. Although station-to-station wind magnitude comparisons cannot be made due to variations in anemometer height and exposure, wind-field

  15. Carbon flux and hypoxia in the Chesapeake Bay

    Science.gov (United States)

    Brodeur, J.; Joesoef, A.; Huang, W. J.; Cai, W. J.

    2016-02-01

    The Chesapeake estuary is the largest in the United States, with more coastline than the entire West Coast. It is one of the most extensively studied aquatic environments in the world. Yet, the inorganic carbon chemistry of the main stem has not been studied, which seriously limits our ability to understand and predict acidification in this large and seasonally hypoxic/anoxic bay. This is an acute problem for resource managers trying to anticipate, monitor and react to ocean acidification. Although most of the estuary is shallow, in the main stem there is a persistent low pH and hypoxic/anoxic zone during the summer through which we can describe the interaction between hypoxia and acidification. A very low pH minimum ( 7.2) was observed at the oxic and anoxic boundary layer, indicating a highly dynamic link of acid-base chemistry to redox reactions and physical mixing. We present several years of observations that begin to describe a baseline of spatial, temporal, and depth profiles of the carbon system in the Chesapeake Bay and possible changes in pH over time.

  16. Wetland habitats for wildlife of the Chesapeake Bay

    Science.gov (United States)

    Perry, M.C.; Majumdar, S.K.; Miller, E.W.; Brenner, Fred J.

    1998-01-01

    The wetlands of Chesapeake Bay have provided the vital habitats that have sustained the impressive wildlife populations that have brought international fame to the Bay. As these wetland habitats decrease in quantity and quality we will continue to see the decline in the wildlife populations that started when European settlers first came to this continent. These declines have accelerated significantly in this century. As the human population continues to increase in the Bay watershed, one can expect that wetland habitats will continue to decline, resulting in declines in species diversity and population numbers. Although federal, state, and local governments are striving for 'no net loss' of wetlands, the results to date are not encouraging. It is unrealistic to believe that human populations and associated development can continue to increase and not adversely affect the wetland resources of the Bay. Restrictions on human population growth in the Chesapeake area is clearly the best way to protect wetland habitats and the wildlife that are dependent on these habitats. In addition, there should be more aggressive approaches to protect wetland habitats from continued perturbations from humans. More sanctuary areas should be created and there should be greater use of enhancement and management techniques that will benefit the full complement of species that potentially exist in these wetlands. The present trend in wetland loss can be expected to continue as human populations increase with resultant increases in roads, shopping malls, and housing developments. Creation of habitat for mitigation of these losses will not result in 'no net loss'. More innovative approaches should be employed to reverse the long-term trend in wetland loss by humans.

  17. Tumor prevalence and biomarkers of genotoxicity in brown bullhead (Ameiurus nebulosus) in Chesapeake Bay tributaries

    Science.gov (United States)

    Pinkney, Alfred E.; Harshbarger, John C.; Karouna-Renier, Natalie K.; Jenko, Kathryn; Balk, Lennart; Skarphéðinsdóttir, Halldora; Liewenborg, Birgitta; Rutter, Michael A.

    2011-01-01

    We surveyed four Chesapeake Bay tributaries for skin and liver tumors in brown bullhead (Ameiurus nebulosus). We focused on the South River, where the highest skin tumor prevalence (53%) in the Bay watershed had been reported. The objectives were to 1) compare tumor prevalence with nearby rivers (Severn and Rhode) and a more remote river (Choptank); 2) investigate associations between tumor prevalence and polynuclear aromatic hydrocarbons (PAHs) and alkylating agents; and 3) statistically analyze Chesapeake Bay bullhead tumor data from 1992 through 2008. All four South River collections exhibited high skin tumor prevalence (19% to 58%), whereas skin tumor prevalence was 2%, 10%, and 52% in the three Severn collections; 0% and 2% in the Choptank collections; and 5.6% in the Rhode collection. Liver tumor prevalence was 0% to 6% in all but one South River collection (20%) and 0% to 6% in the three other rivers. In a subset of samples, PAH-like biliary metabolites and 32P-DNA adducts were used as biomarkers of exposure and response to polycyclic aromatic compounds (PACs). Adducts from alkylating agents were detected as O6-methyl-2'-deoxyguanosine (O6Me-dG) and O6-ethyl-2'-deoxyguanosine (O6Et-dG) modified DNA. Bullheads from the contaminated Anacostia River were used as a positive control for DNA adducts. 32P-DNA adduct concentrations were significantly higher in Anacostia bullhead livers compared with the other rivers. We identified alkyl DNA adducts in bullhead livers from the South and Anacostia, but not the Choptank. Neither the PAH-like bile metabolite data, sediment PAH data, nor the DNA adduct data suggest an association between liver or skin tumor prevalence and exposure to PACs or alkylating agents in the South, Choptank, Severn, or Rhode rivers. Logistic regression analysis of the Chesapeake Bay database revealed that sex and length were significant covariates for liver tumors and length was a significant covariate for skin tumors.

  18. Bald Eagle Movements, Distribution and Abundance on the Northern Chesapeake Bay

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The primary objective of this study was to monitor bald eagle movements and to locate bald eagle intensive use areas on the northern Chesapeake Bay. An important...

  19. Monitoring wetland inundation dynamics in response to weather variability in the Chesapeake Bay watershed

    Science.gov (United States)

    Wetlands provide a broad range of ecosystem services, including flood control, water purification, groundwater replenishment, and biodiversity support. The provision of these services, which are especially valued in the Chesapeake Bay Watershed, is largely controlled by varying levels of wetness. ...

  20. Contaminant exposure and reproductive success of ospreys (Pandion haliaetus) nesting in Chesapeake Bay regions of concern

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Chesapeake Bay osprey population has more than doubled in size since restrictions were placed on the production and use of and other in the 1970s. Ospreys are...

  1. National Status and Trends: Bioeffects Assessment Program, Chesapeake Bay Summary Database (1998-2001)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study was based on the sediment quality triad (SQT) approach. A stratified probabilistic sampling design was utilized to characterize the Chesapeake Bay system...

  2. Changes in Stream Water Temperatures in the Chesapeake Bay Region, 1960-2014

    Data.gov (United States)

    U.S. Environmental Protection Agency — This map shows the changes in stream water temperatures in the Chesapeake Bay region from 1960 to 2014. Blue circles represent cooling trends in stream water...

  3. The record of major quaternary sea-level changes in a large coastal plain estuary, Chesapeake Bay, Eastern United States

    Science.gov (United States)

    Colman, Steven M.; Mixon, R.B.

    1988-01-01

    Seismic-reflection surveys of the Chesapeake Bay, combined with geologic mapping and analysis of boreholes on the Delmarva Peninsula, provide evidence of at least three generations of the Susquehanna River system and three generations of the Chesapeake Bay. The evidence for ancient courses of the Susquehanna River is preserved as three distinct paleochannels, and evidence for ancient versions of the Chesapeake Bay is preserved as three sets of paleochannel fill beneath the bay and three generations of barrier-spit deposits on the southern Delmarva Peninsula. The paleochannels represent relative sea-level minima and the channel-fill and barrier-spit deposits represents relative sea-level maxima. A history of three major marine transgressions is recorded in the stratigraphy preserved in the filled paleochannels and in the overlying barrier-spit complexes: three systematic progressions from fluvial to estuarine to bay or nearshore marine environments. This sea-level record seems to be compatible with the saw-toothed pattern of the marine oxygen-isotope record and with the concept of glacial-interglacial terminations. It also seems to have a climax character in which most of the preserved evidence is related to the largest terminations and to the extreme sea-level positions that bound those terminations. The three paleochannel-fill and barrier-spit complexes appear to correspond to oxygen-isotope stages 1,5, and either 7 or 11; the three related paleochannels correspond to stages 2, 6, and either 8 or 12. ?? 1988.

  4. Direct and indirect estimates of natural mortality for Chesapeake Bay blue crab

    Science.gov (United States)

    Hewitt, D.A.; Lambert, D.M.; Hoenig, J.M.; Lipcius, R.N.; Bunnell, D.B.; Miller, T.J.

    2007-01-01

    Analyses of the population dynamics of blue crab Callinectes sapidus have been complicated by a lack of estimates of the instantaneous natural mortality rate (M). We developed the first direct estimates of M for this species by solving Baranov's catch equation for M given estimates of annual survival rate and exploitation rate. Annual survival rates were estimated from a tagging study on adult female blue crabs in Chesapeake Bay, and female-specific exploitation rates for the same stock were estimated by comparing commercial catches with abundances estimated from a dredge survey. We also used eight published methods based on life history parameters to calculate indirect estimates of M for blue crab. Direct estimates of M for adult females in Chesapeake Bay for the years 2002–2004 ranged from 0.42 to 0.87 per year and averaged 0.71 per year. Indirect estimates of M varied considerably depending on life history parameter inputs and the method used. All eight methods yielded values for M between 0.99 and 1.08 per year, and six of the eight methods yielded values between 0.82 and 1.35 per year. Our results indicate that natural mortality of blue crab is higher than previously believed, and we consider M values between 0.7 and 1.1 per year to be reasonable for the exploitable stock in Chesapeake Bay. Remaining uncertainty about Mmakes it necessary to evaluate a range of estimates in assessment models.

  5. Transitioning a Chesapeake Bay Ecological Prediction System to Operations

    Science.gov (United States)

    Brown, C.; Green, D. S.; Eco Forecasters

    2011-12-01

    Ecological prediction of the impacts of physical, chemical, biological, and human-induced change on ecosystems and their components, encompass a wide range of space and time scales, and subject matter. They vary from predicting the occurrence and/or transport of certain species, such harmful algal blooms, or biogeochemical constituents, such as dissolved oxygen concentrations, to large-scale ecosystem responses and higher trophic levels. The timescales of ecological prediction, including guidance and forecasts, range from nowcasts and short-term forecasts (days), to intraseasonal and interannual outlooks (weeks to months), to decadal and century projections in climate change scenarios. The spatial scales range from small coastal inlets to basin and global scale biogeochemical and ecological forecasts. The types of models that have been used include conceptual, empirical, mechanistic, and hybrid approaches. This presentation will identify the challenges and progress toward transitioning experimental model-based ecological prediction into operational guidance and forecasting. Recent efforts are targeting integration of regional ocean, hydrodynamic and hydrological models and leveraging weather and water service infrastructure to enable the prototyping of an operational ecological forecast capability for the Chesapeake Bay and its tidal tributaries. A path finder demonstration predicts the probability of encountering sea nettles (Chrysaora quinquecirrha), a stinging jellyfish. These jellyfish can negatively impact safety and economic activities in the bay and an impact-based forecast that predicts where and when this biotic nuisance occurs may help management effects. The issuance of bay-wide nowcasts and three-day forecasts of sea nettle probability are generated daily by forcing an empirical habitat model (that predicts the probability of sea nettles) with real-time and 3-day forecasts of sea-surface temperature (SST) and salinity (SSS). In the first demonstration

  6. Conceptual Design of a Chesapeake Bay Environmental Observatory (CBEO)

    Science.gov (United States)

    Ball, W. P.; di Toro, D.; Gross, T. F.; Kemp, W. M.; Burns, R.; Piasecki, M.; Zaslavsky, I.; Cuker, B. E.; Murray, L.

    2006-12-01

    A new project is underway to develop and deploy a Chesapeake Bay Environmental Observatory (CBEO), which is intended to serve as a prototype of cyberinfrastructure (CI) for environmental observatory networks (EONs) that will demonstrate the transformative power of CI. The CBEO will be developed by a team of highly qualified computer scientists, ecologists, oceanographers and environmental engineers with a track record of working together on environmental observatory projects and complex cross-discipline research efforts. The project approach has been organized around the following four concurrent interacting elements, which follow the acronym "NETS": (1) The CBEO:N group will incorporate the test bed CI into the national EONs by constructing a GEON-based node for the CBEO. This will entail resolving complex cross-disciplinary issues of semantics, syntax and inter- operability as well as developing new shared CI tools for data assimilation and interpolation. (2) CBEO:E is the education element and will use the CBEO to translate observational science for public consumption. Direct participation of multicultural students and a K-12 teacher are planned. The test-bed and network components (described below and above) will provide the focus of five workshops for users, managers and science educators; (3) Prior to full integration via CBEO:N, CBEO:T will rapidly construct a locally accessible CBEO test-bed prototype that will integrate a subset of currently available large data sets characterized by multiple variables and widely disparate time and space scales ? grab and continuous sampling at fixed stations, undulating towed sensors, and satellite and aircraft remote sensing. A novel feature will be the inclusion of the fifteen year (1986-2000) simulated data from the Bay-wide fine spatial (1-10 km) and temporal (0.02-1 hr) scale hydrodynamic and water quality model. CBEO:T will serve initially as the development platform for data integration, interpolation, and

  7. Watershed nutrient inputs, phytoplankton accumulation, and C stocks in Chesapeake Bay

    Science.gov (United States)

    Fisher, T. R.; Boynton, W. R.; Hagy, J. D.

    2002-12-01

    Inputs of N and P to Chesapeake Bay have been enhanced by anthropogenic activities. Fertilizers, urbanization, N emissions, and industrial effluents contribute to point and diffuse sources currently 2-7X higher for P and 5-20X higher for N than those from undisturbed watersheds. Enhanced nutrient inputs cause phytoplankton blooms which obscure visibility, eliminate submerged grasses, and influence the distribution of C within the Bay. Accumulations of dissolved organic and particulate organic C lead to enhanced microbial respiration in isolated bottom waters, and dissolved oxygen is seasonally reduced to trace levels during summer. Cultural eutrophication is not unique to Chesapeake Bay. Although some estuaries such as the Delaware, Hudson, and San Francisco Bay also have high anthropogenic inputs, these estuaries have much shorter residence times, and much of the N and P may be exported to the coastal ocean. However, in Chesapeake Bay, with residence times >2 months, internal processing of watershed inputs results in local algal blooms within the estuary. Watershed restoration strategies for Chesapeake watersheds have had limited success to date. Groundwaters are enriched with nitrate, and the long residence times of groundwaters mean slow responses to watershed improvements. The few successes in the Chesapeake have been associated with point source reductions, although continued human population growth can easily override restoration efforts. Widespread improvement in water quality has yet to occur, but the limited successes show that the Bay responds to load changes.

  8. Organic Matter Remineralization Predominates Phosphorus Cycling in the Mid-Bay Sediments in the Chesapeake Bay

    Energy Technology Data Exchange (ETDEWEB)

    Sunendra, Joshi R.; Kukkadapu, Ravi K.; Burdige, David J.; Bowden, Mark E.; Sparks, Donald L.; Jaisi, Deb P.

    2015-05-19

    The Chesapeake Bay, the largest and most productive estuary in the US, suffers from varying degrees of water quality issues fueled by both point and non–point source nutrient sources. Restoration of the bay is complicated by the multitude of nutrient sources, their variable inputs and hydrological conditions, and complex interacting factors including climate forcing. These complexities not only restrict formulation of effective restoration plans but also open up debates on accountability issues with nutrient loading. A detailed understanding of sediment phosphorus (P) dynamics enables one to identify the exchange of dissolved constituents across the sediment- water interface and aid to better constrain mechanisms and processes controlling the coupling between the sediments and the overlying waters. Here we used phosphate oxygen isotope ratios (δ18Op) in concert with sediment chemistry, XRD, and Mössbauer spectroscopy on the sediment retrieved from an organic rich, sulfidic site in the meso-haline portion of the mid-bay to identify sources and pathway of sedimentary P cycling and to infer potential feedback effect on bottom water hypoxia and surface water eutrophication. Isotope data indicate that the regeneration of inorganic P from organic matter degradation (remineralization) is the predominant, if not sole, pathway for authigenic P precipitation in the mid-bay sediments. We interpret that the excess inorganic P generated by remineralization should have overwhelmed any bottom-water and/or pore-water P derived from other sources or biogeochemical processes and exceeded saturation with respect to authigenic P precipitation. It is the first research that identifies the predominance of remineralization pathway against remobilization (coupled Fe-P cycling) pathway in the Chesapeake Bay. Therefore, these results are expected to have significant implications for the current understanding of P cycling and benthic-pelagic coupling in the bay, particularly on the

  9. Organic matter remineralization predominates phosphorus cycling in the mid-Bay sediments in the Chesapeake Bay.

    Science.gov (United States)

    Joshi, Sunendra R; Kukkadapu, Ravi K; Burdige, David J; Bowden, Mark E; Sparks, Donald L; Jaisi, Deb P

    2015-05-19

    Chesapeake Bay, the largest and most productive estuary in the U.S., suffers from varying degrees of water quality issues fueled by both point and nonpoint nutrient sources. Restoration of the Bay is complicated by the multitude of nutrient sources, their variable inputs, and complex interaction between imported and regenerated nutrients. These complexities not only restrict formulation of effective restoration plans but also open up debates on accountability issues with nutrient loading. A detailed understanding of sediment phosphorus (P) dynamics provides information useful in identifying the exchange of dissolved constituents across the sediment-water interface as well as helps to better constrain the mechanisms and processes controlling the coupling between sediments and the overlying waters. Here we used phosphate oxygen isotope ratios (δ(18)O(P)) in concert with sediment chemistry, X-ray diffraction, and Mössbauer spectroscopy on sediments retrieved from an organic rich, sulfidic site in the mesohaline portion of the mid-Bay to identify sources and pathway of sedimentary P cycling and to infer potential feedbacks on bottom water hypoxia and surface water eutrophication. Authigenic phosphate isotope data suggest that the regeneration of inorganic P from organic matter degradation (remineralization) is the predominant, if not sole, pathway for authigenic P precipitation in the mid-Bay sediments. This indicates that the excess inorganic P generated by remineralization should have overwhelmed any pore water and/or bottom water because only a fraction of this precipitates as authigenic P. This is the first research that identifies the predominance of remineralization pathway and recycling of P within the Chesapeake Bay. Therefore, these results have significant implications on the current understanding of sediment P cycling and P exchange across the sediment-water interface in the Bay, particularly in terms of the sources and pathways of P that sustain hypoxia

  10. Oyster Reef Communities in the Chesapeake Bay. Virginia Institute of Marine Science Educational Series. [CD-ROM].

    Science.gov (United States)

    Harding, Juliana M.; Mann, Roger; Clark, Vicki P.

    This CD-ROM, Oyster Reef Communities in the Chesapeake Bay, describes oyster reefs, reef communities, and their roles in the Chesapeake Bay ecosystem. Detailed descriptions of scientific research methods and techniques used to monitor and describe oyster reef communities as well as applications of the resulting data are provided. The CD-ROM was…

  11. Foraminiferal repopulation of the late Eocene Chesapeake Bay impact crater

    Science.gov (United States)

    Poag, C. Wylie

    2012-01-01

    The Chickahominy Formation is the initial postimpact deposit in the 85km-diameter Chesapeake Bay impact crater, which is centered under the town of Cape Charles, Virginia, USA. The formation comprises dominantly microfossil-rich, silty, marine clay, which accumulated during the final ~1.6myr of late Eocene time. At cored sites, the Chickahominy Formation is 16.8-93.7m thick, and fills a series of small troughs and subbasins, which subdivide the larger Chickahominy basin. Nine coreholes drilled through the Chickahominy Formation (five inside the crater, two near the crater margin, and two ~3km outside the crater) record the stratigraphic and paleoecologic succession of 301 indigenous species of benthic foraminifera, as well as associated planktonic foraminifera and bolboformids. Two hundred twenty of these benthic species are described herein, and illustrated with scanning electron photomicrographs. Absence of key planktonic foraminiferal and Bolboforma species in early Chickahominy sediments indicates that detrimental effects of the impact also disturbed the upper oceanic water column for at least 80-100kyr postimpact. After an average of ~73kyr of stressed, rapidly fluctuating paleoenvironments, which were destabilized by after-effects of the impact, most of the cored Chickahominy subbasins maintained stable, nutrient-rich, low-oxygen bottom waters and interstitial microhabitats for the remaining ~1.3myr of late Eocene time.

  12. Modeling Land Use Change in the Chesapeake Bay Watershed

    Science.gov (United States)

    Claire, J. A.; Goetz, S. J.; Bockstael, N.

    2003-12-01

    Low density, decentralized residential and commercial development is increasingly the dominant pattern of exurban land use in many developed countries, particularly the United States. The term "sprawl" is now commonly used to describe this form of development, the environmental and quality-of-life impacts of which are becoming central to debates over land use in urban and suburban areas. Continued poor health of the Chesapeake Bay, located in the Mid-Atlantic region of the United States, is due in part to disruptions in the hydrological system caused by urban and suburban development throughout the 167,000 square kilometer watershed. We present results of a spatial predictive model of land use change based on cellular automata (SLEUTH), which was calibrated using high resolution (30m cell size) maps of the built environment derived from Landsat ETM+ imagery for the period 1986-2000. The model was applied to a 23,740 square kilometer area centered on Washington DC - Baltimore MD, and predictions were made out to 2030 assuming three different policy scenarios (current trends, managed growth, and "sustainable"). Accuracy of the model was assessed at three scales (pixel, watershed and county) and overall strengths and weaknesses of the model are presented, particularly in comparison to other econometric modeling approaches.

  13. Identification of largemouth bass virus in the introduced Northern Snakehead inhabiting the Chesapeake Bay watershed.

    Science.gov (United States)

    Iwanowicz, L; Densmore, C; Hahn, C; McAllister, P; Odenkirk, J

    2013-09-01

    The Northern Snakehead Channa argus is an introduced species that now inhabits the Chesapeake Bay. During a preliminary survey for introduced pathogens possibly harbored by these fish in Virginia waters, a filterable agent was isolated from five specimens that produced cytopathic effects in BF-2 cells. Based on PCR amplification and partial sequencing of the major capsid protein (MCP), DNA polymerase (DNApol), and DNA methyltransferase (Mtase) genes, the isolates were identified as Largemouth Bass virus (LMBV). Nucleotide sequences of the MCP (492 bp) and DNApol (419 pb) genes were 100% identical to those of LMBV. The nucleotide sequence of the Mtase (206 bp) gene was 99.5% identical to that of LMBV, and the single nucleotide substitution did not lead to a predicted amino acid coding change. This is the first report of LMBV from the Northern Snakehead, and provides evidence that noncentrarchid fishes may be susceptible to this virus.

  14. Composition and temporal patterns of larval fish communities in Chesapeake and Delaware Bays

    Directory of Open Access Journals (Sweden)

    Filipe Ribeiro

    2015-11-01

    Full Text Available Comparing larval fish assemblages in different estuaries provides insights about the coastal distribution of larval populations, larval transport, and adult spawning locations (Ribeiro et al. 2015. We simultaneously compared the larval fish assemblages entering two Middle Atlantic Bight (MAB estuaries (Delaware Bay and Chesapeake Bay, USA through weekly sampling from 2007 to 2009. In total, 43 taxa (32 families and 36 taxa (24 families were collected in Delaware and Chesapeake Bays, respectively. Mean taxonomic diversity, mean richness, and evenness were generally lower in Delaware Bay. Communities of both bays were dominated by Anchoa spp., Gobiosoma spp., Micropogonias undulatus, and Brevoortia tyrannus; Paralichthys spp. was more abundant in Delaware Bay and Microgobius thalassinus was more abundant in Chesapeake Bay. Inter-annual variation in the larval fish communities was low at both sites, with a relatively consistent composition across years, but strong seasonal (intra-annual variation in species composition occurred in both bays. Two groups were identified in Chesapeake Bay: a ‘winter’ group dominated by shelf-spawned species (e.g. M. undulatus and a ‘summer’ group comprising obligate estuarine species and coastal species (e.g. Gobiosoma spp. and Cynoscion regalis, respectively. In Delaware Bay, 4 groups were identified: a ‘summer’ group of mainly obligate estuarine fishes (e.g. Menidia sp. being replaced by a ‘fall’ group (e.g. Ctenogobius boleosoma and Gobionellus oceanicus; ‘winter’ and ‘spring’ groups were dominated by shelf-spawned (e.g. M. undulatus and Paralichthys spp. and obligate estuarine species (e.g. Leiostomus xanthurus and Pseudopleuronectes americanus, respectively. This study demonstrates that inexpensive and simultaneous sampling in different estuaries provides important insights into the variability in community structure of fish assemblages at large spatial scales.

  15. Integrating Federal and State data records to report progress in establishing agricultural conservation practices on Chesapeake Bay farms

    Science.gov (United States)

    Hively, W. Dean; Devereux, Olivia H.; Claggett, Peter

    2013-01-01

    In response to the Executive Order for Chesapeake Bay Protection and Restoration (E.O. #13508, May 12, 2009), the U.S. Geological Survey (USGS) took on the task of acquiring and assessing agricultural conservation practice data records for U.S. Department of Agriculture (USDA) programs, and transferred those datasets in aggregated format to State jurisdictional agencies for use in reporting conservation progress to the Chesapeake Bay Program Partnership (CBP Partnership). Under the guidelines and regulations that have been developed to protect and restore water-quality in the Chesapeake Bay, the six State jurisdictions that fall within the Chesapeake Bay watershed are required to report their progress in promoting agricultural conservation practices to the CBP Partnership on an annual basis. The installation and adoption of agricultural best management practices is supported by technical and financial assistance from both Federal and State conservation programs. The farm enrollment data for USDA conservation programs are confidential, but agencies can obtain access to the privacy-protected data if they are established as USDA Conservation Cooperators. The datasets can also be released to the public if they are first aggregated to protect farmer privacy. In 2012, the USGS used its Conservation Cooperator status to obtain implementation data for conservation programs sponsored by the USDA Natural Resources Conservation Service (NRCS) and the USDA Farm Service Agency (FSA) for farms within the Chesapeake Bay watershed. Three jurisdictions (Delaware, Pennsylvania, and West Virginia) used the USGS-provided aggregated dataset to report conservation progress in 2012, whereas the remaining three jurisdictions (Maryland, New York, and Virginia) used jurisdictional Conservation Cooperator Agreements to obtain privacy-protected data directly from the USDA. This report reviews the status of conservation data sharing between the USDA and the various jurisdictions, discusses the

  16. Derivation of habitat-specific dissolved oxygen criteria for Chesapeake Bay and its tidal tributaries

    Science.gov (United States)

    Batiuk, R.A.; Breitburg, D.L.; Diaz, R.J.; Cronin, T. M.; Secor, D.H.; Thursby, G.

    2009-01-01

    The Chesapeake 2000 Agreement committed its state and federal signatories to "define the water quality conditions necessary to protect aquatic living resources" in the Chesapeake Bay (USA) and its tidal tributaries. Hypoxia is one of the key water quality issues addressed as a result of the above Agreement. This paper summarizes the protection goals and specific criteria intended to achieve those goals for addressing hypoxia. The criteria take into account the variety of Bay habitats and the tendency towards low dissolved oxygen in some areas of the Bay. Stressful dissolved oxygen conditions were characterized for a diverse array of living resources of the Chesapeake Bay by different aquatic habitats: migratory fish spawning and nursery, shallow-water, open-water, deep-water, and deep-channel. The dissolved oxygen criteria derived for each of these habitats are intended to protect against adverse effects on survival, growth, reproduction and behavior. The criteria accommodate both spatial and temporal aspects of low oxygen events, and have been adopted into the Chesapeake Bay states - Maryland, Virginia, and Delaware - and the District of Columbia's water quality standards regulations. These criteria, now in the form of state regulatory standards, are driving an array of land-based and wastewater pollution reduction actions across the six-watershed.

  17. History of the Virginia Oyster Fishery, Chesapeake Bay, USA

    Directory of Open Access Journals (Sweden)

    David M. Schulte

    2017-05-01

    Full Text Available Oyster populations in Virginia's waters of Chesapeake Bay were lightly exploited until the early 1800s, when industrial fishery vessels first arrived, driven south from New England due to the collapse of northeastern oyster fisheries. Early signs of overexploitation and habitat degradation were evident by the 1850s. The public fishery, where oyster fishers harvest on state-owned bottom, rapidly developed after the Civil War and peaked in the early 1880s. Declines were noted by the late 1880s and eventually prompted the creation of Virginia's shell-planting and oyster-seed (young-of-the-year, YOY moving repletion program in the 1920s. Despite management and increasing repletion efforts, the public fishery collapsed (annual landings <10% of peak historical landings by the early 1960s. The private leasehold fishery, in which individuals rent areas outside the public grounds to plant shells and oysters for their own private use, surpassed the public fishery by the late 1920s, which partly masked this decline due to overfishing, habitat degradation, and diseases until both public and private fisheries completely collapsed in the mid-1980s after a third disease outbreak. This disease outbreak was likely related to warming waters. Overfishing and concomitant habitat loss followed a pattern of sequential population collapses observed in wild oyster fisheries along the Coastlines of the United States and worldwide. In recent years, expanding hatchery-produced seed oysters and aquaculture significantly increased leasehold landings. The wild fishery has also increased as disease resistance is developing naturally in the wild stocks, but remains ~5% of peak landings. Improved management has assisted in this recent limited recovery, improving these efforts further by enhancing stock recovery via large no-take sanctuaries, among other actions, could assist in stock recovery.

  18. Paleontological interpretations of crater processes and infilling of synimpact sediments from the Chesapeake Bay impact structure

    Science.gov (United States)

    Self-Trail, Jean M.; Edwards, Lucy E.; Litwin, Ronald J.

    2009-01-01

    Biostratigraphic analysis of sedimentary breccias and diamictons in the Chesapeake Bay impact structure provides information regarding the timing and processes of late-stage gravitational crater collapse and ocean resurge. Studies of calcareous nannofossil and palynomorph assemblages in the International Continental Scientific Drilling Program (ICDP)–U.S. Geological Survey (USGS) Eyreville A and B cores show the mixed-age, mixed-preservation microfossil assemblages that are typical of deposits from the upper part of the Chesapeake Bay impact structure. Sparse, poorly preserved, possibly thermally altered pollen is present within a gravelly sand interval below the granite slab at 1392 m in Eyreville core B, an interval that is otherwise barren of calcareous nannofossils and dinocysts. Gravitational collapse of water- saturated sediments from the transient crater wall resulted in the deposition of sediment clasts primarily derived from the nonmarine Cretaceous Potomac Formation. Collapse occurred before the arrival of resurge. Low pollen Thermal Alteration Index (TAI) values suggest that these sediments were not thermally altered by contact with the melt sheet. The arrival of resurge sedimentation is identified based on the presence of diamicton zones and stringers rich in glauconite and marine microfossils at 866.7 m. This horizon can be traced across the crater and can be used to identify gravitational collapse versus ocean-resurge sedimentation. Glauconitic quartz sand diamicton dominates the sediments above 618.2 m. Calcareous nannofossil and dino-flagellate data from this interval suggest that the earliest arriving resurge from the west contained little or no Cretaceous marine input, but later resurge pulses mined Cretaceous sediments east of the Watkins core in the annular trough. Additionally, the increased distance traveled by resurge to the central crater in turbulent flow conditions resulted in the disaggregation of Paleogene unconsolidated sediments. As

  19. A summary report of sediment processes in Chesapeake Bay and watershed

    Science.gov (United States)

    Langland, Michael; Cronin, Thomas

    2003-01-01

    The Chesapeake Bay, the Nation's largest estuary, has been degraded because of diminished water quality, loss of habitat, and over-harvesting of living resources. Consequently, the bay was listed as an impaired water body due to excess nutrients and sediment. The Chesapeake Bay Program (CBP), a multi-jurisdictional partnership, completed an agreement called ?Chesapeake 2000? that revises and establishes new restoration goals through 2010 in the bay and its watershed. The goal of this commitment is the removal of the bay from the list of impaired waterbodies by the year 2010. The CBP is committed to developing sediment and nutrient allocations for major basins within the bay watershed and to the process of examining new and innovative management plans in the estuary itself and along the coastal zones of the bay. However, additional information is required on the sources, transport, and deposition of sediment that affect water clarity. Because the information and data on sediment processes in the bay were not readily accessible to the CBP or to state, and local managers, a Sediment Workgroup (SWGP) was created in 2001. The primary objective of this report, therefore, is to provide a review of the literature on the sources, transport, and delivery of sediment in Chesapeake Bay and its watershed with discussion of potential implications for various management alternatives. The authors of the report have extracted, discussed, and summarized the important aspects of sediment and sedimentation that are most relevant to the CBP and other sediment related-issues with which resources managers are involved. This report summarizes the most relevant studies concerning sediment sources, transport and deposition in the watershed and estuary, sediments and relation to water clarity, and provides an extensive list of references for those wanting more information.

  20. Physical property data from the ICDP-USGS Eyreville cores A and B, Chesapeake Bay impact structure, Virginia, USA, acquired using a multisensor core logger

    Science.gov (United States)

    Pierce, H.A.; Murray, J.B.

    2009-01-01

    The International Continental Scientific Drilling Program (ICDP) and the U.S. Geological Survey (USGS) drilled three core holes to a composite depth of 1766 m within the moat of the Chesapeake Bay impact structure. Core recovery rates from the drilling were high (??90%), but problems with core hole collapse limited the geophysical downhole logging to natural-gamma and temperature logs. To supplement the downhole logs, ??5% of the Chesapeake Bay impact structure cores was processed through the USGS GeoTek multisensor core logger (MSCL) located in Menlo Park, California. The measured physical properties included core thickness (cm), density (g cm-3), P-wave velocity (m s-1), P-wave amplitude (%), magnetic susceptibility (cgs), and resistivity (ohm-m). Fractional porosity was a secondary calculated property. The MSCL data-sampling interval for all core sections was 1 cm longitudinally. Photos of each MSCL sampled core section were imbedded with the physical property data for direct comparison. These data have been used in seismic, geologic, thermal history, magnetic, and gravity models of the Chesapeake Bay impact structure. Each physical property curve has a unique signature when viewed over the full depth of the Chesapeake Bay impact structure core holes. Variations in the measured properties reflect differences in pre-impact target-rock lithologies and spatial variations in impact-related deformation during late-stage crater collapse and ocean resurge. ?? 2009 The Geological Society of America.

  1. 33 CFR 334.350 - Chesapeake Bay off Fort Monroe, Va.; firing range danger zone.

    Science.gov (United States)

    2010-07-01

    ..., Va.; firing range danger zone. 334.350 Section 334.350 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.350 Chesapeake Bay off Fort Monroe, Va.; firing range danger zone. (a) The danger zone. All of...

  2. 33 CFR 334.140 - Chesapeake Bay; U.S. Army Proving Ground Reservation, Aberdeen, Md.

    Science.gov (United States)

    2010-07-01

    ....140 Chesapeake Bay; U.S. Army Proving Ground Reservation, Aberdeen, Md. (a) Restricted area defined. The following indicates the limits of the waters of or adjacent to the Aberdeen Proving Ground, Maryland, and inside of which boundaries will lie the restricted area known as the Aberdeen Proving...

  3. EPA Interim Evaluation of 2012-2013 Milestone Progress in the Chesapeake Bay Watershed

    Science.gov (United States)

    This page provides the EPA interim evaluations of the 2012-2013 milestones for the Chesapeake Bay TMDL. These interim assessments provide a mid-point check on the progress made on the 2012-2013 milestones, recognizing the achievements made in 2012.

  4. 33 CFR 334.220 - Chesapeake Bay, south of Tangier Island, Va.; naval firing range.

    Science.gov (United States)

    2010-07-01

    ... Island, Va.; naval firing range. 334.220 Section 334.220 Navigation and Navigable Waters CORPS OF....220 Chesapeake Bay, south of Tangier Island, Va.; naval firing range. (a) The danger zone. Beginning... the range will be conducted intermittently by one or more vessels, depending on weather and...

  5. Oyster Reef Communities in the Chesapeake Bay: A Brief Primer. VORTEX: Virginia's Oyster Reef Teaching EXperience.

    Science.gov (United States)

    Harding, Juliana M.; Mann, Roger; Clark, Vicki P.

    This document introduces Virginia's Oyster Reef Teaching EXperience (VORTEX), which is an interdisciplinary program focusing on the importance of oyster reef communities in the Chesapeake Bay ecosystem. The VORTEX program uses field and laboratory experience supported by multimedia instruction. This document presents an overview on the biology of…

  6. SETTLEMENT AND SURVIVAL OF THE OYSTER CRASSOSTREA VIRGINICA ON CREATED OYSTER REEF HABITATS IN CHESAPEAKE BAY

    Science.gov (United States)

    Efforts to restore the Eastern oyster (Crassostrea virginica) reef habitats in Chesapeake Bay typically begin with the placement of hard substrata to form three-dimensional mounds on the seabed to serve as a base for oyster recruitment and growth. A shortage of oyster shell for ...

  7. 33 CFR 165.507 - Security Zone; Chesapeake Bay, between Sandy Point and Kent Island, MD.

    Science.gov (United States)

    2010-07-01

    ... south (eastbound) span of the William P. Lane Jr. Memorial Bridge, from the western shore at Sandy Point..., between Sandy Point and Kent Island, MD. 165.507 Section 165.507 Navigation and Navigable Waters COAST... Guard District § 165.507 Security Zone; Chesapeake Bay, between Sandy Point and Kent Island, MD. (a...

  8. 75 FR 34367 - Safety Zone; Shore Thing & Independence Day Fireworks, Chesapeake Bay, Norfolk, VA

    Science.gov (United States)

    2010-06-17

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Shore Thing & Independence Day Fireworks... is establishing a temporary safety zone on the Chesapeake Bay in the vicinity of Ocean View Beach Park, Norfolk, VA in support of the Shore Thing & Independence Day Fireworks event. This action...

  9. 76 FR 38300 - Safety Zone; Shore Thing and Independence Day Fireworks, Chesapeake Bay, Norfolk, VA

    Science.gov (United States)

    2011-06-30

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Shore Thing and Independence Day Fireworks... is establishing a temporary safety zone on the Chesapeake Bay in the vicinity of Ocean View Beach Park, Norfolk, VA in support of the Shore Thing and Independence Day Fireworks event. This action...

  10. 3 CFR 13508 - Executive Order 13508 of May 12, 2009. Chesapeake Bay Protection and Restoration

    Science.gov (United States)

    2010-01-01

    ..., the Clean Water Act, and other laws; (c) strengthen storm water management practices at Federal... storm water management practices at Federal facilities and on Federal lands under subsection (c). The... the Chesapeake Bay; (b) are based on sound science and reflect adaptive management principles; (c) are...

  11. Integrated analysis of ecosystem interactions with land use Change: The Chesapeake Bay watershed

    Science.gov (United States)

    Goetz, Scott J.; Jantz, Claire A.; Prince, Stephen D.; Smith, Andrew J.; Varlyguin, Dmitry; Wright, Robb K.

    The Chesapeake Bay is the largest estuary in the United States, encompassed by a watershed extending 168,000 km2 over portions of six states and Washington, D.C. Restoration of the Bay has been the focus of a two-decade regional partnership of local, state and federal agencies, including a network of scientists, politicians and activists interacting through various committees, working groups, and advisory panels. The effectiveness of the restoration effort has been mixed, with both notable successes and failures. The overall health of the Bay has not declined since the restoration was initiated in 1983, but many of the advances have been offset by the pressure of increasing population and exurban sprawl across the watershed. The needs of the Chesapeake Bay Program are many, but the greatest is accurate information on land cover and land use change, primarily to assess the implications for water quality, examine various restoration scenarios, and calibrate spatial models of the urbanization process. We report here on a number of new land cover and land use data products, and associated applications to assist vulnerability assessment, integrated ecosystem analysis, and ultimately Bay restoration. We provide brief overviews of applications to model new residential development, assess losses and vulnerability of resource lands, and identify the factors that disrupt the health of streams in small watersheds. These data products and approaches are being applied by a number of agencies involved with the restoration effort, including the Chesapeake Bay Program's activities focused on living resources, water quality, and sound land use.

  12. Understanding nutrients in the Chesapeake Bay watershed and implications for management and restoration: the Eastern Shore

    Science.gov (United States)

    Ator, Scott W.; Denver, Judith M.

    2015-03-12

    The Eastern Shore includes only a small part of the Chesapeake Bay watershed, but contributes disproportionately large loads of the excess nitrogen and phosphorus that have contributed to ecological and economic degradation of the bay in recent decades. Chesapeake Bay is the largest estuary in the United States and a vital ecological and economic resource. The bay and its tributaries have been degraded in recent decades by excessive nitrogen and phosphorus in the water column, however, which cause harmful algal blooms and decreased water clarity, submerged aquatic vegetation, and dissolved oxygen. The disproportionately large nitrogen and phosphorus yields from the Eastern Shore to Chesapeake Bay are attributable to human land-use practices as well as natural hydrogeologic and soil conditions. Applications of nitrogen and phosphorus compounds to the Eastern Shore from human activities are intensive. More than 90 percent of nitrogen and phosphorus reaching the land in the Eastern Shore is applied as part of inorganic fertilizers or manure, or (for nitrogen) fixed directly from the atmosphere in cropland. Also, hydrogeologic and soil conditions promote the movement of these compounds from application areas on the landscape to groundwater and (or) surface waters, and the proximity of much of the Eastern Shore to tidal waters limits opportunities for natural removal of these compounds in the landscape. The Eastern Shore only includes 7 percent of the Chesapeake Bay watershed, but receives nearly twice as much nitrogen and phosphorus applications (per area) as the remainder of the watershed and yields greater nitrogen and phosphorus, on average, to the bay. Nitrogen and phosphorus commonly occur in streams at concentrations that may adversely affect aquatic ecosystems and have increased in recent decades.

  13. Shipboard magnetic field "noise" reveals shallow heavy mineral sediment concentrations in Chesapeake Bay

    Science.gov (United States)

    Shah, Anjana K.; Vogt, Peter R.; Rosenbaum, Joseph G.; Newell, Wayne; Cronin, Thomas M.; Willard, Debra A.; Hagen, Rick A.; Brozena, John; Hofstra, Albert

    2012-01-01

    Shipboard magnetic field data collected over Chesapeake Bay exhibit low-amplitude, short-wavelength anomalies that most likely indicate shallow concentrations of heavy mineral sediments. Piston core layers and black sand beach samples exhibit enhanced magnetic susceptibilities and carry remanent magnetization, with mineralogical analyses indicating ilmenite and trace magnetite and/or maghemite and hematite. The anomalies are subtle and would be filtered as noise using traditional approaches, but can instead be highlighted using spectral methods, thus providing nearly continuous coverage along survey tracks. The distribution of the anomalies provides constraints on relevant sorting mechanisms. Comparisons to sonar data and previous grab samples show that two of three areas surveyed exhibit short-wavelength anomalies that are clustered over sand-covered areas, suggesting initial sorting through settling mechanisms. This is supported by a correlation between core magnetic susceptibility and grain size. Near the Choptank River, where sediment resuspension is wave-dominated, anomalies show a sharp decrease with seafloor depth that cannot be explained by signal attenuation alone. In Pocomoke Sound, where both tidal currents and wave-action impact sediment resuspension, anomalies show a more gradual decrease with depth. Near the mouth of the bay, where there is a higher influx of sediments from the continental shelf, short-wavelength anomalies are isolated and do not appear to represent heavy mineral sand concentrations. These combined observations suggest the importance of further sorting by erosional processes in certain parts of the bay. Additionally, comparisons of these data to cores sampling pre-Holocene sediments suggest that the sorting of heavy minerals in higher energy, shallow water environments provides a mechanism for correlations between core magnetic susceptibility and sea-level changes.

  14. In plain sight: the Chesapeake Bay crater ejecta blanket

    Directory of Open Access Journals (Sweden)

    D. L. Griscom

    2012-02-01

    Full Text Available The discovery nearly two decades ago of a 90 km-diameter impact crater below the lower Chesapeake Bay has gone unnoted by the general public because to date all published literature on the subject has described it as "buried". To the contrary, evidence is presented here that the so-called "upland deposits" that blanket ∼5000 km2 of the U.S. Middle-Atlantic Coastal Plain (M-ACP display morphologic, lithologic, and stratigraphic features consistent with their being ejecta from the 35.4 Ma Chesapeake Bay Impact Structure (CBIS and absolutely inconsistent with the prevailing belief that they are of fluvial origin. Specifically supporting impact origin are the facts that (i a 95 %-pure iron ore endemic to the upland deposits of southern Maryland, eastern Virginia, and the District of Columbia has previously been proven to be impactoclastic in origin, (ii this iron ore welds together a small percentage of well-rounded quartzite pebbles and cobbles of the upland deposits into brittle sheets interpretable as "spall plates" created in the interference-zone of the CBIS impact, (iii the predominantly non-welded upland gravels have long ago been shown to be size sorted with an extreme crater-centric gradient far too large to have been the work of rivers, but well explained as atmospheric size-sorted interference-zone ejecta, (iv new evidence is provided here that ~60 % of the non-welded quartzite pebbles and cobbles of the (lower lying gravel member of the upland deposits display planar fractures attributable to interference-zone tensile waves, (v the (overlying loam member of the upland deposits is attributable to base-surge-type deposition, (vi several exotic clasts found in a debris flow topographically below the upland deposits can only be explained as jetting-phase crater ejecta, and (vii an allogenic granite boulder found among the upland deposits is deduced to have been launched into space and sculpted by hypervelocity air friction

  15. A Model for the Formation of the Chesapeake Bay Impact Crater as Revealed by Drilling and Numerical Simulation

    Science.gov (United States)

    Collins, G. S.; Kenkmann, T.; Wünnemann, K.; Wittmann, A.; Reimold, W. U.; Melosh, H. J.

    The combination of numerical simulation results and petrographic analysis of drill core from the recent ICDP-USGS drilling project provides new insight into the formation of the Chesapeake Bay impact crater.

  16. Multi-decadal variation in size of juvenile Summer Flounder (Paralichthys dentatus) in Chesapeake Bay

    Science.gov (United States)

    Nys, Lauren N.; Fabrizio, Mary C.; Tuckey, Troy D.

    2016-01-01

    During the last quarter-century, management of Summer Flounder Paralichthys dentatus along the Atlantic coast resulted in significant increases in abundance such that rebuilding targets were recently achieved. Although spawning stock biomass is high, recruitment of young-of-the-year (YOY) Summer Flounder remains variable. Chesapeake Bay is one of the principal nursery areas for this species, but processes such as growth and survival that affect production of YOY Summer Flounder in this estuary have not been explored. Here, we investigated the relationship between abundance and size of Summer Flounder recruits from the 1988 to 2012 year classes in Chesapeake Bay. We also considered the effects of environmental factors on fish size because conditions in the bay vary spatially during the time that fish occupy nursery areas. To describe variations in Summer Flounder size, we used monthly length observations from 13,018 YOY fish captured by bottom trawl from the lower Chesapeake Bay and the James, York, and Rappahannock river subestuaries where Summer Flounder are commonly observed. We applied a generalized additive model to describe spatial, temporal, and environmental effects on observed fish size; we also considered the density of Summer Flounder and an index of productivity as factors in the model. Summer Flounder in Chesapeake Bay exhibited density-dependent and spatially related variations in mean length: larger fish were found mostly in the Bay and smaller fish in the subestuaries. Additionally, low ( 26 °C) temperatures and low salinities (fish size, indicating that individuals found in these environments were typically smaller than conspecifics inhabiting areas of moderate temperatures and higher salinities. Variable nursery habitat conditions in temperate estuaries affect fish size and, subsequently, may influence production of Summer Flounder year classes through effects on maturation and survival. As water temperatures in the mid-Atlantic region continue to

  17. Goddard DEVELOP Students: Using NASA Remote Sensing Technology to Study the Chesapeake Bay Watershed

    Science.gov (United States)

    Moore, Rachel

    2011-01-01

    The DEVELOP National Program is an Earth Science research internship, operating under NASA s Applied Sciences Program. Each spring, summer, and fall, DEVELOP interns form teams to investigate Earth Science related issues. Since the Fall of 2003, Goddard Space Flight Center (GSFC) has been home to one of 10 national DEVELOP teams. In past terms, students completed a variety of projects related to the Applied Sciences Applications of National Priority, such as Public Health, Natural Disasters, Water Resources, and Ecological Forecasting. These projects have focused on areas all over the world, including the United States, Africa, and Asia. Recently, Goddard DEVELOP students have turned their attention to a local environment, the Chesapeake Bay Watershed. The Chesapeake Bay Watershed is a complex and diverse ecosystem, spanning approximately 64,000 square miles. The watershed encompasses parts of six states: Delaware, Maryland, New York, Pennsylvania, Virginia, and West Virginia, as well as the District of Columbia. The Bay itself is the biggest estuary in the United States, with over 100,000 tributaries feeding into it. The ratio of fresh water to salt water varies throughout the Bay, allowing for a variety of habitats. The Bay s wetlands, marshes, forests, reefs, and rivers support more than 3,600 plant and animal species, including birds, mammals, reptiles, amphibians, fish, and crabs. The Bay is also commercially significant. It is ranked third in the nation in fishery catch, and supplies approximately 500 million pounds of seafood annually. In addition to its abundant flora and fauna, the Chesapeake Bay watershed is home to approximately 16.6 million people, who live and work throughout the watershed, and who use its diverse resources for recreational purposes. Over the past several decades, the population throughout the watershed has increased rapidly, resulting in land use changes, and ultimately decreasing the health of the Chesapeake Bay Watershed. Over the

  18. Influence of Conowingo Reservoir Infill on Chesapeake Bay Deep Water Hypoxia

    Science.gov (United States)

    Linker, L. C.; Cerco, C. F.; Batiuk, R.

    2014-12-01

    The Chesapeake Bay Total Maximum Daily Load (TMDL) requires the reduction of nitrogen, phosphorus, and sediment loads in the Chesapeake watershed because of the tidal water quality impairments and the damage to living resources they cause. Within the Chesapeake watershed the Conowingo Reservoir has been filling in with sediment for almost a century, and is now in a state of near-full capacity called dynamic equilibrium. The development of the Chesapeake TMDL in 2010 was with the hydrology of a 1991-2000 simulation period, and carried with this simulation period the implicit model calibration assumption, based on the 1991-2000 nutrient and sediment observations, of a Conowingo Reservoir that was still effectively trapping sediment. In a TMDL, pollutant loads beyond the TMDL allocation, which are brought about by growth or other conditions, must be offset. Using the analysis tools of the Chesapeake TMDL for assessing the degree of attainment of living resource based water quality standards, the estimated nutrient and sediment loads from a simulated infill of the Conowingo Reservoir was determined. The influence on Chesapeake water quality by a large storm and scour event of January 1996 on the Susquehanna was estimated and the same storm and scour events were also evaluated in the more critical living resource periods of June and October. An analysis was also made on the estimated influence of more moderate but frequent high flow events. The infill of the Conowingo reservoir had estimated impairments of water quality at both the simulated high flow scour events and at the more frequent moderate storm flows. The estimated impairment was primarily on the deep water and deep channel dissolved oxygen because of increased scour and transport of dissolved particulate organic nutrients under conditions of Conowingo infill. Figure 1 describes the linked models used to assess the impact of Conowingo Reservoir infill on Chesapeake hypoxia.

  19. Pressure and temperature profile data collected by the NOAA vessel Bay Hydrographer during survey operations along the NE US coast, 03 February 2005 to 21 November 2005 (NODC Accession 0002670)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pressure and temperature profile data were collected using CTD casts from the NOAA Survey Vessel BAY HYDROGRAPHER. Data were collected in the Chesapeake Bay from...

  20. Remote sensing of submerged aquatic vegetation in the lower Chesapeake Bay. [(sea grasses)

    Science.gov (United States)

    Orth, R. J.; Gordon, H. R.

    1975-01-01

    An experimental water penetration film and black and white near infrared film were used to study the distribution of submerged aquatic vegetation in the lower Chesapeake Bay. Detailed description of the grass beds was obtained by flying at an altitude of 5,000 feet, at low tide when wind conditions were minimal. Results show that there was a 36% reduction in the amount of submerged aquatic vegetation in the lower Chesapeake Bay from 1971 to 1974, the greatest losses occurring in the York, Piankatank and Rappahannock rivers (tabulated data is given). Recovery of some grass beds occurs primarily through seedling recruitment and subsequent vegetative growth. Cownose rays are suspected as a main factor for the decimation of some of the grass beds. Maps and photographs of the areas studied are given.

  1. What drives interannual variability of hypoxia in Chesapeake Bay: Climate forcing versus nutrient loading?

    Science.gov (United States)

    Li, Ming; Lee, Younjoo J.; Testa, Jeremy M.; Li, Yun; Ni, Wenfei; Kemp, W. Michael; Di Toro, Dominic M.

    2016-03-01

    Oxygen depletion in estuaries is a worldwide problem with detrimental effects on many organisms. Although nutrient loading has been stabilized for a number of these systems, seasonal hypoxia persists and displays large year-to-year variations, with larger hypoxic volumes in wetter years and smaller hypoxic volumes in drier years. Data analysis points to climate as a driver of interannual hypoxia variability, but nutrient inputs covary with freshwater flow. Here we report an oxygen budget analysis of Chesapeake Bay to quantify relative contributions of physical and biogeochemical processes. Vertical diffusive flux declines with river discharge, whereas longitudinal advective flux increases with river discharge, such that their total supply of oxygen to bottom water is relatively unchanged. However, water column respiration exhibits large interannual fluctuations and is correlated with primary production and hypoxic volume. Hence, the model results suggest that nutrient loading is the main mechanism driving interannual hypoxia variability in Chesapeake Bay.

  2. Modeling hypoxia in the Chesapeake Bay: Ensemble estimation using a Bayesian hierarchical model

    Science.gov (United States)

    Stow, Craig A.; Scavia, Donald

    2009-02-01

    Quantifying parameter and prediction uncertainty in a rigorous framework can be an important component of model skill assessment. Generally, models with lower uncertainty will be more useful for prediction and inference than models with higher uncertainty. Ensemble estimation, an idea with deep roots in the Bayesian literature, can be useful to reduce model uncertainty. It is based on the idea that simultaneously estimating common or similar parameters among models can result in more precise estimates. We demonstrate this approach using the Streeter-Phelps dissolved oxygen sag model fit to 29 years of data from Chesapeake Bay. Chesapeake Bay has a long history of bottom water hypoxia and several models are being used to assist management decision-making in this system. The Bayesian framework is particularly useful in a decision context because it can combine both expert-judgment and rigorous parameter estimation to yield model forecasts and a probabilistic estimate of the forecast uncertainty.

  3. Chesapeake Bay recovery and factors affecting trends: Long-termmonitoring, indicators, and insights

    Science.gov (United States)

    Tango, Peter J.; Batiuk, Richard A.

    2016-01-01

    Monitoring the outcome of restoration efforts is the only way to identify the status of a recovery and the most effective management strategies. In this paper, we discuss Chesapeake Bay and watershed recovery and factors influencing water quality trends. For over 30 years, the Chesapeake Bay Program Partnership’s long-term tidal and watershed water quality monitoring networks have measured physical, chemical and biological parameters throughout the bay and its surrounding watershed underpinning an adaptive management process to drive ecosystem recovery. There are many natural and anthropogenic factors operating and interacting to affect the watershed and bay water quality recovery responses to management actions. Across habitats and indicators, the bay and its watershed continue to express a diverse spatial and temporal fabric of multiscale conditions, stressors and trends that show a range of health conditions and impairments, as well as evidence of progress and degradation. Recurrent independent reviews of the monitoring program have driven a culture of continued adaptation of the monitoring networks to reflect ever evolving management information needs. The adherence to bay and watershed-wide consistent monitoring protocols provides monitoring data supporting analyses and development of scientific syntheses that underpin indicator and model development, regulatory assessments, targeting of management actions, evaluation of management effectiveness, and directing of priorities and policies.

  4. A hydrologic network supporting spatially referenced regression modeling in the Chesapeake Bay Watershed.

    Science.gov (United States)

    Brakebill, John W; Preston, Stephen D

    2003-01-01

    The U.S. Geological Survey has developed a methodology for statistically relating nutrient sources and land-surface characteristics to nutrient loads of streams. The methodology is referred to as SPAtially Referenced Regressions On Watershed attributes (SPARROW), and relates measured stream nutrient loads to nutrient sources using nonlinear statistical regression models. A spatially detailed digital hydrologic network of stream reaches, stream-reach characteristics such as mean streamflow, water velocity, reach length, and travel time, and their associated watersheds supports the regression models. This network serves as the primary framework for spatially referencing potential nutrient source information such as atmospheric deposition, septic systems, point-sources, land use, land cover, and agricultural sources and land-surface characteristics such as land use, land cover, average-annual precipitation and temperature, slope, and soil permeability. In the Chesapeake Bay watershed that covers parts of Delaware, Maryland, Pennsylvania, New York, Virginia, West Virginia, and Washington D.C., SPARROW was used to generate models estimating loads of total nitrogen and total phosphorus representing 1987 and 1992 land-surface conditions. The 1987 models used a hydrologic network derived from an enhanced version of the U.S. Environmental Protection Agency's digital River Reach File, and course resolution Digital Elevation Models (DEMs). A new hydrologic network was created to support the 1992 models by generating stream reaches representing surface-water pathways defined by flow direction and flow accumulation algorithms from higher resolution DEMs. On a reach-by-reach basis, stream reach characteristics essential to the modeling were transferred to the newly generated pathways or reaches from the enhanced River Reach File used to support the 1987 models. To complete the new network, watersheds for each reach were generated using the direction of surface-water flow derived

  5. Large-Scale Submerged Aquatic Vegetation Restoration in Chesapeake Bay: Status Report, 2003-2006

    Science.gov (United States)

    2008-06-01

    marina), (2) wild celery (V. americana), (3) sago pondweed (S. pectinata), and (4) redhead grass (P. perfoliatus). Molecular and cultivation...depth and density on germination and development of Zostera marina L. seeds. Biologia Marina Mediterranea 7(3):55–58. Granger, S., M. Traber, S. W...sago pondweed (S. pectinata), and redhead grass (P. perfoliatus) collected from different regions of the Chesapeake Bay. Molecular and cultivation

  6. Evaluation of groundwater resources of the Chesapeake Bay Watershed using an integrated hydrologic model

    Science.gov (United States)

    Seck, A.; Welty, C.; Maxwell, R. M.

    2013-12-01

    We present results from a distributed integrated hydrologic model of the Chesapeake Bay Watershed using ParFlow-CLM. The model covers an area of 400,000 km2 spanning five physiographic provinces, discretized at a horizontal resolution of 2 km and vertical resolution of 5 m. Synthesis of published hydrogeologic data as well as analysis of well completion reports from state agencies were used to construct a hydrogeologic model framework. The model was run for the period of 2003-2004 using National Land Data Assimilation System (NLDAS) meteorological forcing. Model output captures seasonal and spatial variability in subsurface storage and surface storage, and produces water table depths consistent with the topography, meteorological forcing, and hydrogeological setting. Model results show spatial variability in evaporation fluxes correlated to land cover at higher resolution than either NLDAS outputs or the EPA Chesapeake Bay Watershed Model Phase 5.3. Comparison with USGS streamflow data at selected stream gages shows good agreement in daily discharge timing and fluxes for high and average flows, whereas the model does not perform as well for low flows during summer and dry periods. Analysis of groundwater stores and fluxes showed marked variability across physiographic provinces. Highest groundwater stores were expectedly found in the Coastal Plain, while the Blue Ridge physiographic province had the lowest stores. The Appalachian Plateau was characterized by the highest net recharge rates. The highest discharge rates were found in the Valley and Ridge, Piedmont and Coastal Plain. The construction of this model constitutes a step forward in understanding the groundwater system in the Chesapeake Bay Watershed and its role in solute delivery to the Chesapeake Bay.

  7. Millennial-scale sustainability of the Chesapeake Bay Native American oyster fishery.

    Science.gov (United States)

    Rick, Torben C; Reeder-Myers, Leslie A; Hofman, Courtney A; Breitburg, Denise; Lockwood, Rowan; Henkes, Gregory; Kellogg, Lisa; Lowery, Darrin; Luckenbach, Mark W; Mann, Roger; Ogburn, Matthew B; Southworth, Melissa; Wah, John; Wesson, James; Hines, Anson H

    2016-06-07

    Estuaries around the world are in a state of decline following decades or more of overfishing, pollution, and climate change. Oysters (Ostreidae), ecosystem engineers in many estuaries, influence water quality, construct habitat, and provide food for humans and wildlife. In North America's Chesapeake Bay, once-thriving eastern oyster (Crassostrea virginica) populations have declined dramatically, making their restoration and conservation extremely challenging. Here we present data on oyster size and human harvest from Chesapeake Bay archaeological sites spanning ∼3,500 y of Native American, colonial, and historical occupation. We compare oysters from archaeological sites with Pleistocene oyster reefs that existed before human harvest, modern oyster reefs, and other records of human oyster harvest from around the world. Native American fisheries were focused on nearshore oysters and were likely harvested at a rate that was sustainable over centuries to millennia, despite changing Holocene climatic conditions and sea-level rise. These data document resilience in oyster populations under long-term Native American harvest, sea-level rise, and climate change; provide context for managing modern oyster fisheries in the Chesapeake Bay and elsewhere around the world; and demonstrate an interdisciplinary approach that can be applied broadly to other fisheries.

  8. Long-term reductions in anthropogenic nutrients link to improvements in Chesapeake Bay habitat

    Science.gov (United States)

    Ruhl, H.A.; Rybicki, N.B.

    2010-01-01

    Great effort continues to focus on ecosystem restoration and reduction of nutrient inputs thought to be responsible, in part, for declines in estuary habitats worldwide. The ability of environmental policy to address restoration is limited, in part, by uncertainty in the relationships between costly restoration and benefits. Here, we present results from an 18-y field investigation (1990-2007) of submerged aquatic vegetation (SAV) community dynamics and water quality in the Potomac River, a major tributary of the Chesapeake Bay. River and anthropogenic discharges lower water clarity by introducing nutrients that stimulate phytoplankton and epiphyte growth as well as suspended sediments. Efforts to restore the Chesapeake Bay are often viewed as failing. Overall nutrient reduction and SAV restoration goals have not been met. In the Potomac River, however, reduced in situ nutrients, wastewater-treatment effluent nitrogen, and total suspended solids were significantly correlated to increased SAV abundance and diversity. Species composition and relative abundance also correlated with nutrient and water-quality conditions, indicating declining fitness of exotic species relative to native species during restoration. Our results suggest that environmental policies that reduce anthropogenic nutrient inputs do result in improved habitat quality, with increased diversity and native species abundances. The results also help elucidate why SAV cover has improved only in some areas of the Chesapeake Bay.

  9. Anatomy of the Chesapeake Bay impact structure revealed by seismic imaging, Delmarva Peninsula, Virginia, USA

    Science.gov (United States)

    Catchings, R.D.; Powars, D.S.; Gohn, G.S.; Horton, J.W.; Goldman, M.R.; Hole, J.A.

    2008-01-01

    A 30-km-long, radial seismic reflection and refraction survey completed across the northern part of the late Eocene Chesapeake Bay impact structure (CBIS) on the Delmarva Peninsula, Virginia, USA, confirms that the CBIS is a complex central-peak crater. We used a tomographic P wave velocity model and low-fold reflection images, constrained by data from two deep boreholes located on the profile, to interpret the structure and composition of the upper 5 km of crust. The seismic images exhibit well-defined structural features, including (with increasing radial distance) a collapsed central uplift, a breccia-filled moat, and a collapsed transient-crater margin (which collectively constitute a ???40-km-wide collapsed transient crater), and a shallowly deformed annular trough. These seismic images are the first to resolve the deep structure of the crater (>1 km) and the boundaries between the central uplift, moat, and annular trough. Several distinct seismic signatures distinguish breccia units from each other and from more coherent crystalline rocks below the central uplift, moat, and annular trough. Within the moat, breccia extends to a minimum depth of 1.5 km or a maximum of 3.5 km, depending upon the interpretation of the deepest layered materials. The images show ???350 to 500 m of postimpact sediments above the impactites. The imaged structure of the CBIS indicates a complex sequence of event during the cratering process that will provide new constraints for numerical modeling. Copyright 2008 by the American Geophysical Union.

  10. Contamination assessment in microbiological sampling of the Eyreville core, Chesapeake Bay impact structure

    Science.gov (United States)

    Gronstal, A.L.; Voytek, M.A.; Kirshtein, J.D.; Von der, Heyde; Lowit, M.D.; Cockell, C.S.

    2009-01-01

    Knowledge of the deep subsurface biosphere is limited due to difficulties in recovering materials. Deep drilling projects provide access to the subsurface; however, contamination introduced during drilling poses a major obstacle in obtaining clean samples. To monitor contamination during the 2005 International Continental Scientific Drilling Program (ICDP)-U.S. Geological Survey (USGS) deep drilling of the Chesapeake Bay impact structure, four methods were utilized. Fluorescent microspheres were used to mimic the ability of contaminant cells to enter samples through fractures in the core material during retrieval. Drilling mud was infused with a chemical tracer (Halon 1211) in order to monitor penetration of mud into cores. Pore water from samples was examined using excitation-emission matrix (EEM) fl uorescence spectroscopy to characterize dissolved organic carbon (DOC) present at various depths. DOC signatures at depth were compared to signatures from drilling mud in order to identify potential contamination. Finally, microbial contaminants present in drilling mud were identified through 16S ribosomal deoxyribonucleic acid (rDNA) clone libraries and compared to species cultured from core samples. Together, these methods allowed us to categorize the recovered core samples according to the likelihood of contamination. Twenty-two of the 47 subcores that were retrieved were free of contamination by all the methods used and were subsequently used for microbiological culture and culture-independent analysis. Our approach provides a comprehensive assessment of both particulate and dissolved contaminants that could be applied to any environment with low biomass. ?? 2009 The Geological Society of America.

  11. Remote sensing of particle backscattering in Chesapeake Bay: a 6-year SeaWiFS retrospective view

    Science.gov (United States)

    Zawada, D.G.; Hu, C.; Clayton, T.; Chen, Z.; Brock, J.C.; Muller-Karger, F. E.

    2007-01-01

    Traditional field techniques to monitor water quality in large estuaries, such as boat-based surveys and autonomous moored sensors, generally provide limited spatial coverage. Satellite imagery potentially can be used to address both of these limitations. Here, we show that satellite-based observations are useful for inferring total-suspended-solids (TSS) concentrations in estuarine areas. A spectra-matching optimization algorithm was used to estimate the particle backscattering coefficient at 400 nm, bbp(400), in Chesapeake Bay from Sea-viewing Wide-Field-of-view Sensor (SeaWiFS) satellite imagery. These estimated values of bbp(400) were compared to in situ measurements of TSS for the study period of September 1997–December 2003. Contemporaneous SeaWiFS bbp(400) values and TSS concentrations were positively correlated (N = 340, r2 = 0.4, P bp(400) values served as a reasonable first-order approximation for synoptically mapping TSS. Overall, large-scale patterns of SeaWiFS bbp(400) appeared to be consistent with expectations based on field observations and historical reports of TSS. Monthly averages indicated that SeaWiFS bbp(400) was typically largest in winter (>0.049 m−1, November–February) and smallest in summer (−1, June–August), regardless of the amount of riverine discharge to the bay. The study period also included Hurricanes Floyd and Isabel, which caused large-scale turbidity events and changes in the water quality of the bay. These results demonstrate that this technique can provide frequent synoptic assessments of suspended solids concentrations in Chesapeake Bay and other coastal regions.

  12. The Baltimore Engineers and the Chesapeake Bay, 1961-1987

    Science.gov (United States)

    1988-01-01

    Bay’s ecosystem was still quite sparse, the study provided an overview of the natural and man-made forces operating in the Bay and its watershed and...Susquehanna and Potomac nozzles gushed forth in a large seemingly steady stream while other very small ones dribbled out a stream that was hardly...Engineer District, 1984), p. 11, Table II-I. 5. An excellent brief overview to the Bay’s ecosystem is the U.S. Environmental Protection Agency

  13. Atmospheric exchange of PAHs, PCBs, and ammonia with the Chesapeake Bay

    Science.gov (United States)

    Larsen, Randolph Kenneth, III

    This study combines long term measurements of precipitation, gas and aerosols at urban and rural settings in the mid-Atlantic to provide a holistic analysis of the impact from direct transmission of semi-volatile compounds between the atmosphere and the Chesapeake Bay. Three groups of semi-volatile compounds were investigated, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and ammonia. Elevated levels of these contaminants contribute to impairing the Chesapeake Bay water quality. The geometric mean concentrations (and geometric standard deviation) of the total gas phase PAHs (sum of 32 PAHs) were 41 (1.9), 29 (2), and 5.6 (2.2) ng m-3 at Baltimore, Solomons, and Stillpond, respectively. The geometric mean concentrations (and geometric standard deviation) of the Sigma32 particle bound PAHs at Baltimore, Solomons, and Stillpond were 3.2 (1.9), 0.51 (2.1), and 0.74 (1.5) ng m-3, respectively. The geometric mean (and geometric standard deviation) at Baltimore and Stillpond for total PCB concentrations were 435 (2) and 95 (2) pg m-3 in the gas phase, respectively. Mean and arithmetic standard deviations of atmospheric total ammonia concentrations at Baltimore and Solomons were 2.7 +/- 1.7 and 1.0 +/- 0.8 mug N m-3, respectively. Results of three source apportionment models suggested that sources of atmospheric PAHs in Baltimore were vehicles (17 to 22%), coal (26 to 32%), oil (18 to 22%), and wood/other sources (17 to 40%). The net direct fluxes of these compounds to the Chesapeake Bay were calculated from these measurements. The primary mechanism for the transfer of most of these chemicals across the air-water interface was gas exchange. The degraded air and water quality of Baltimore with respect to these compounds resulted in significant fluxes both into and out of the water. For example, fluxes in Baltimore were +/-1000 mug N m-2 d-1 for ammonia, 114 mug m-2 y-1 for the SigmaPCB, and 780, mug m-2 y -1 for fluorene. The magnitude of the

  14. Impact of sea level rise on tidal range in Chesapeake and Delaware Bays

    Science.gov (United States)

    Lee, Serena Blyth; Li, Ming; Zhang, Fan

    2017-05-01

    Coastal inundation is affected not only by rising mean sea level but also by changing tides. A numerical model is developed to investigate how sea level rise and coastline changes may impact tides in two coastal-plain estuaries, Chesapeake Bay and Delaware Bay. Despite their different tidal characteristics, the two estuaries display similar responses to the sea level rise and shoreline management scenarios. When hypothetic sea walls are erected at the present coastline to prevent low-lying land from flooding, tidal range increases, with greater amplification in the upper part of the two estuaries. When low-lying land is allowed to become permanently inundated by higher sea level, however, tidal range in both estuaries decreases. Analyses of the tidal energy budget show that the increased dissipation over the shallow water and newly inundated areas compensates for the reduced dissipation in deep water, leading to smaller tidal range. The changes in the tidal range are not proportional to the changes in the mean sea level, indicating a nonlinear tidal response to sea level rise. The ratio of tidal range change to sea level rise varies between -0.05 and 0.1 in Chesapeake Bay and between -0.2 and 0.25 in Delaware Bay. The model results suggest a potential adaptation strategy that uses inundation over low-lying areas to reduce tidal range at up-estuary locations.

  15. Quantifying groundwater’s role in delaying improvements to Chesapeake Bay water quality

    Science.gov (United States)

    Sanford, Ward E.; Pope, Jason P.

    2013-01-01

    A study has been undertaken to determine the time required for the effects of nitrogen-reducing best management practices (BMPs) implemented at the land surface to reach the Chesapeake Bay via groundwater transport to streams. To accomplish this, a nitrogen mass-balance regression (NMBR) model was developed and applied to seven watersheds on the Delmarva Peninsula. The model included the distribution of groundwater return times obtained from a regional groundwater-flow (GWF) model, the history of nitrogen application at the land surface over the last century, and parameters that account for denitrification. The model was (1) able to reproduce nitrate concentrations in streams and wells over time, including a recent decline in the rate at which concentrations have been increasing, and (2) used to forecast future nitrogen delivery from the Delmarva Peninsula to the Bay given different scenarios of nitrogen load reduction to the water table. The relatively deep porous aquifers of the Delmarva yield longer groundwater return times than those reported earlier for western parts of the Bay watershed. Accordingly, several decades will be required to see the full effects of current and future BMPs. The magnitude of this time lag is critical information for Chesapeake Bay watershed managers and stakeholders.

  16. The Lower Chesapeake Bay LTAR: A coastal urban-agricultural region

    Science.gov (United States)

    Mccarty, G.; Alfieri, J. G.; Cavigelli, M.; Cosh, M. H.; Hapeman, C. J.; Kustas, W. P.; Maul, J.; Mirsky, S.; Pooler, M.; Sadeghi, A. M.; Schomberg, H.; Timlin, D. J.; Rice, C. P.

    2015-12-01

    The Chesapeake Bay, located in the mid-Atlantic region of the U.S., is the largest estuary in North America. The watershed area includes six states from New York to Virginia and is nearly 167,000 km2 in size with more than 150 rivers and streams entering the 300-km Bay main stem. Forested and agricultural lands make up 58 and 22 percent of the land use, respectively. Nearly 9 percent is urban and suburban use, and the watershed is home to over 17 million people. However, the population is expected to reach 19 million by 2025, raising the potential for conflict between the agricultural and urban communities over land and water use and in protecting natural resources, especially in the lower portion of the Chesapeake Bay watershed. The Lower Chesapeake Bay study area, part of the USDA-ARS Long-Term Agroecosystem Research (LTAR) network, will provide much-needed data to support decisions at this critical agriculture-urban interface. Current long-term projects seek to assess the economic, production, and environmental performance of conventional and organic cropping systems and to evaluate the resilience of these systems to climate change. Large-scale studies are being conducted to examine the effects of land-use and landscape characteristics on ecosystem services and on energy, water, nutrient, carbon, and pest dynamics within watersheds. New in-situ measurement and remote sensor technologies are being considered with the expectancy that the data streams will be available on-line and for use in modeling. Results and outcomes of these research efforts will greatly benefit the national LTAR network and will be applicable to other US coastal urban-agricultural regions.

  17. Hydrologic landscapes on the Delmarva Peninsula - Part 2: Estimates of base-flow nitrogen load to Chesapeake Bay

    Science.gov (United States)

    Joseph, Bachman L.; Phillips, P.J.

    1996-01-01

    Base-flow samples were collected from 47 sampling sites for four seasons from 1990-91 on the Delmarva Peninsula in Delaware and Maryland to relate stream chemistry to a "hydrologic landscape" and season. Two hydrologic landscapes were determined: (1) a well-drained landscape, characterized by a combination of a low percentage of forest cover, a low percentage of poorly drained soil, and elevated channel slope; and (2) poorly drained landscape, characterized by a combination of an elevated percentage of forest cover, an elevated percentage of poorly drained soil, and low channel slope. Concentrations of nitrogen were significantly related to the hydrologic landscape. Nitrogen concentrations tended to be higher in well-drained landscapes than in poorly drained ones. The highest instantaneous nitrogen yields occurred in well-drained landscapes during the winter. These yields were extrapolated over the part of the study area draining to Chesapeake Bay in order to provide a rough estimate of nitrogen load from base flow to the Bay and its estuarine tributaries. This estimate was compared to an estimate made by extrapolating from an existing long-term monitoring station. The load estimate from the stream survey data was 5 ?? 106 kg of N per year, which was about four times the estimate made from the existing long-term monitoring station. The stream-survey estimate of base flow represents about 40 percent of the total nitrogen load that enters the Bay and estuarine tributaries from all sources in the study area.

  18. Particle size distribution of suspended solids in the Chesapeake Bay entrance and adjacent shelf waters

    Science.gov (United States)

    Byrnes, M. R.; Oertel, G. F.

    1981-01-01

    Characteristics of suspended solids, including total suspended matter, total suspended inorganics, total suspended organics, particle size distribution, and the presence of the ten most prominent particle types were determined. Four research vessels simultaneously collected samples along four transects. Samples were collected within a 2-hour period that coincided with the maximum ebb penetration of Chesapeake Bay outwelling. The distribution of primary and secondary particle size modes indicate the presence of a surface or near-surface plume, possibly associated with three sources: (1) runoff, (2) resuspension of material within the Bay, and/or (3) resuspension of material in the area of shoals at the Bay mouth. Additional supportive evidence for this conclusion is illustrated with ocean color scanner data.

  19. High-resolution seismic reflection/refraction images near the outer margin of the Chesapeake Bay impact crater, York-James Peninsula, southeastern Virginia

    Science.gov (United States)

    Catchings, R.D.; Saulter, D.E.; Powars, D.S.; Goldman, M.R.; Dingler, J.A.; Gohn, G.S.; Schindler, J.S.; Johnson, G.H.

    2001-01-01

    faults and fractures in basement are not well determined. To better determine some of the unknowns associated with the CBIC, we conducted a 350-m-long, high-resolution seismic reflection and refraction survey, referred to here as the CBIC-1 seismic survey, on the York-James Peninsula in June 1999. In particular, we attempted to: better define the outer margin of the CBIC, understand lateral variations in the stratigraphic sequence, help assess potential hazards associated with regional seismicity, and determine acquisition parameters needed for shallow-depth seismic imaging in the Chesapeake Bay area.

  20. Water column particulate matter: A key contributor to phosphorus regeneration in a coastal eutrophic environment, the Chesapeake Bay: Particulate phosphorus in the Chesapeake Bay

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jiying [Department of Plant and Soil Sciences, University of Delaware, Newark Delaware USA; Reardon, Patrick [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland Washington USA; Now at NMR Facility, Oregon State University, Corvallis Oregon USA; McKinley, James P. [Geochemistry Group, Pacific Northwest National Laboratory, Richland Washington USA; Joshi, Sunendra R. [Department of Plant and Soil Sciences, University of Delaware, Newark Delaware USA; Bai, Yuge [Department of Plant and Soil Sciences, University of Delaware, Newark Delaware USA; Bear, Kristi [Department of Plant and Soil Sciences, University of Delaware, Newark Delaware USA; Jaisi, Deb P. [Department of Plant and Soil Sciences, University of Delaware, Newark Delaware USA

    2017-04-01

    Particulate phosphorus (PP) in the water column is an essential component of phosphorus (P) cycling in aquatic ecosystems yet its composition and transformations remain largely uncharacterized. To understand the roles of suspended particulates on regeneration of inorganic P (Pi) into the water column as well as sequestration into more stable mineral precipitates, we studied seasonal variation in both organic and inorganic P speciation in suspended particles in three sites in the Chesapeake Bay using sequential P extraction, 1D (31P) and 2D (1H-31P) nuclear magnetic resonance (NMR) spectroscopies, and electron microprobe analyses (EMPA). Remineralization efficiency of particulate P average 8% and 56% in shallow and deep sites respectively, suggesting the importance of PP remineralization is in resupplying water column Pi. Strong temporal and spatial variability of organic P composition, distributions, and remineralization efficiency were observed relating to water column parameters such as temperature and redox conditions: concentration of orthophosphate monoesters and diesters, and diester-to-monoester (D/M) ratios decreased with depth. Both esters and the D/M ratios were lower in the hypoxic July and September. In contrast, pyrophosphate and orthophosphate increased with depth, and polyphosphates was high in the anoxic water column. Sequential extraction and EMPA analyses of the suspended particles suggest presence of Ca-bound phosphate in the water column. We hypothesize authigenic precipitation of carbonate fluorapatite and/or its precursor mineral(s) in Pi rich water column, supported by our thermodynamic calculations. Our results, overall, reveal the important role suspended particles play in P remineralization and P sequestration in the Chesapeake Bay water column, provide important implications on P bioavailability and P sinks in similar eutrophic coastal environments.

  1. Ecological Forecasting in Chesapeake Bay: Using a Mechanistic-Empirical Modelling Approach

    Energy Technology Data Exchange (ETDEWEB)

    Brown, C. W.; Hood, Raleigh R.; Long, Wen; Jacobs, John M.; Ramers, D. L.; Wazniak, C.; Wiggert, J. D.; Wood, R.; Xu, J.

    2013-09-01

    The Chesapeake Bay Ecological Prediction System (CBEPS) automatically generates daily nowcasts and three-day forecasts of several environmental variables, such as sea-surface temperature and salinity, the concentrations of chlorophyll, nitrate, and dissolved oxygen, and the likelihood of encountering several noxious species, including harmful algal blooms and water-borne pathogens, for the purpose of monitoring the Bay's ecosystem. While the physical and biogeochemical variables are forecast mechanistically using the Regional Ocean Modeling System configured for the Chesapeake Bay, the species predictions are generated using a novel mechanistic empirical approach, whereby real-time output from the coupled physical biogeochemical model drives multivariate empirical habitat models of the target species. The predictions, in the form of digital images, are available via the World Wide Web to interested groups to guide recreational, management, and research activities. Though full validation of the integrated forecasts for all species is still a work in progress, we argue that the mechanistic–empirical approach can be used to generate a wide variety of short-term ecological forecasts, and that it can be applied in any marine system where sufficient data exist to develop empirical habitat models. This paper provides an overview of this system, its predictions, and the approach taken.

  2. Chesapeake Bay fish–osprey (Pandion haliaetus) food chain: Evaluation of contaminant exposure and genetic damage

    Science.gov (United States)

    Lazarus, Rebecca; Rattner, Barnett A.; McGowan, Peter C.; Hale, Robert C.; Karouna-Reiner, Natalie K.; Erickson, Richard A.; Ottinger, Mary Ann

    2016-01-01

    From 2011 to 2013, a large-scale ecotoxicological study was conducted in several Chesapeake Bay (USA) tributaries (Susquehanna River and flats, the Back, Baltimore Harbor/Patapsco Rivers, Anacostia/ middle Potomac, Elizabeth and James Rivers) and Poplar Island as a mid-Bay reference site. Osprey (Pandion haliaetus) diet and the transfer of contaminants from fish to osprey eggs were evaluated. The most bioaccumulative compounds (biomagnification factor > 5) included p,p′-dichlorodiphenyldichloroethylene (DDE), total polychlorinated biphenyls (PCBs), total polybrominated diphenyl ethers (PBDEs), and bromodiphenyl ether (BDE) congeners 47, 99, 100, and 154. This analysis suggested that alternative brominated flame retardants and other compounds (methoxytriclosan) are not appreciably biomagnifying. A multivariate analysis of similarity indicated that major differences in patterns among study sites were driven by PCB congeners 105, 128, 156, 170/190, and 189, and PBDE congeners 99 and 209. An integrative redundancy analysis showed that osprey eggs from Baltimore Harbor/Patapsco River and the Elizabeth River had high residues of PCBs and p,p′-DDE, with PBDEs making a substantial contribution to overall halogenated contamination on the Susquehanna and Anacostia/middle Potomac Rivers. The redundancy analysis also suggested a potential relation between PBDE residues in osprey eggs and oxidative DNA damage in nestling blood samples. The results also indicate that there is no longer a discernible relation between halogenated contaminants in osprey eggs and their reproductive success in Chesapeake Bay. Osprey populations are thriving in much of the Chesapeake, with productivity rates exceeding those required to sustain a stable population.

  3. Challenges associated with modeling low-oxygen waters in Chesapeake Bay: a multiple model comparison

    Directory of Open Access Journals (Sweden)

    I. D. Irby

    2015-12-01

    Full Text Available As three-dimensional (3-D aquatic ecosystem models are becoming used more frequently for operational water quality forecasts and ecological management decisions, it is important to understand the relative strengths and limitations of existing 3-D models of varying spatial resolution and biogeochemical complexity. To this end, two-year simulations of the Chesapeake Bay from eight hydrodynamic-oxygen models have been statistically compared to each other and to historical monitoring data. Results show that although models have difficulty resolving the variables typically thought to be the main drivers of dissolved oxygen variability (stratification, nutrients, and chlorophyll, all eight models have significant skill in reproducing the mean and seasonal variability of dissolved oxygen. In addition, models with constant net respiration rates independent of nutrient supply and temperature reproduced observed dissolved oxygen concentrations about as well as much more complex, nutrient-dependent biogeochemical models. This finding has significant ramifications for short-term hypoxia forecasts in the Chesapeake Bay, which may be possible with very simple oxygen parameterizations, in contrast to the more complex full biogeochemical models required for scenario-based forecasting. However, models have difficulty simulating correct density and oxygen mixed layer depths, which are important ecologically in terms of habitat compression. Observations indicate a much stronger correlation between the depths of the top of the pycnocline and oxycline than between their maximum vertical gradients, highlighting the importance of the mixing depth in defining the region of aerobic habitat in the Chesapeake Bay when low-oxygen bottom waters are present. Improvement in hypoxia simulations will thus depend more on the ability of models to reproduce the correct mean and variability of the depth of the physically driven surface mixed layer than the precise magnitude of the

  4. Challenges associated with modeling low-oxygen waters in Chesapeake Bay: a multiple model comparison

    Science.gov (United States)

    Irby, Isaac D.; Friedrichs, Marjorie A. M.; Friedrichs, Carl T.; Bever, Aaron J.; Hood, Raleigh R.; Lanerolle, Lyon W. J.; Li, Ming; Linker, Lewis; Scully, Malcolm E.; Sellner, Kevin; Shen, Jian; Testa, Jeremy; Wang, Hao; Wang, Ping; Xia, Meng

    2016-04-01

    As three-dimensional (3-D) aquatic ecosystem models are used more frequently for operational water quality forecasts and ecological management decisions, it is important to understand the relative strengths and limitations of existing 3-D models of varying spatial resolution and biogeochemical complexity. To this end, 2-year simulations of the Chesapeake Bay from eight hydrodynamic-oxygen models have been statistically compared to each other and to historical monitoring data. Results show that although models have difficulty resolving the variables typically thought to be the main drivers of dissolved oxygen variability (stratification, nutrients, and chlorophyll), all eight models have significant skill in reproducing the mean and seasonal variability of dissolved oxygen. In addition, models with constant net respiration rates independent of nutrient supply and temperature reproduced observed dissolved oxygen concentrations about as well as much more complex, nutrient-dependent biogeochemical models. This finding has significant ramifications for short-term hypoxia forecasts in the Chesapeake Bay, which may be possible with very simple oxygen parameterizations, in contrast to the more complex full biogeochemical models required for scenario-based forecasting. However, models have difficulty simulating correct density and oxygen mixed layer depths, which are important ecologically in terms of habitat compression. Observations indicate a much stronger correlation between the depths of the top of the pycnocline and oxycline than between their maximum vertical gradients, highlighting the importance of the mixing depth in defining the region of aerobic habitat in the Chesapeake Bay when low-oxygen bottom waters are present. Improvement in hypoxia simulations will thus depend more on the ability of models to reproduce the correct mean and variability of the depth of the physically driven surface mixed layer than the precise magnitude of the vertical density gradient.

  5. Sediment Retention Dynamics and Vegetation Along Three Tributaries of the Chesapeake Bay

    Science.gov (United States)

    Ross, K.; Ross, K.; Hupp, C.; Alexander, L.; Alexander, L.

    2001-12-01

    Coastal Plain riparian wetlands in the Mid-Atlantic United States are the last place for sediment and contaminant storage before reaching critical estuarine and marine environments. The deteriorating health of the Chesapeake Bay has been attributed in part to elevated sediment loads. The purpose of this study is to investigate the effects of channelization and urbanization on sediment deposition and geomorphic processes along the Pocomoke and Chickahominy Rivers and Dragon Run, three Coastal Plain tributaries. Floodplain microtopography was surveyed in 100 x 100 m grids at three characteristic reaches along each river and woody vegetation analyses were conducted. Floodplain suspended sediment concentrations and short and long-term sedimentation rates were estimated at each reach using single stage sediment sampler arrays, clay pads and dendrogeomorphic techniques, respectively. Site hydroperiod and flow characteristics were determined from USGS gaging station records, floodplain water level recorders, and field observations. Channelized floodplain reaches along the Pocomoke River are flooded less frequently, have lower mineral sedimentation rates (2 mm/yr to 6 mm/yr) and woody species diversity than the unchannelized reaches. Along the Chickahominy River, floodplain wetlands close to urban centers are flooded more frequently, but have shorter hydroperiods (3.5 days/yr compared to more than 45 days/yr), lower sedimentation rates (1.8 mm/yr to 6.8 mm/yr), and lower woody species diversity (0.51 to 1.95 on the Shannon-Weiner diversity index) than floodplains further downstream. Suspended sediment delivery and deposition rates are significantly influenced by floodplain hydroperiod duration and channel-floodplain connectivity. These results suggest that understanding floodplain sediment dynamics and geomorphic processes with respect to dominant watershed landuse patterns is critical for effective water quality management and restoration efforts.

  6. Detection of luciferase gene sequences in nonluminescent bacteria from the Chesapeake Bay

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Chun, J.; Ravel, J.; Straube, W.L.; Hill, R.T.; Colwell, R.R.

    , Yusong Taejon 305-600, Republic of South Korea. FEMSEC 1139 20-7-00 FEMS Microbiology Ecology 33 (2000) 27^34 www.fems-microbiology.org detectable levels to over 20% of the culturable popula- tions [1,11,12]. The number of bacteria capable of express- ing... after a period of dark adaptation of 20 min. A luminometer (ML1000; Dy- natech Laboratories) was used to examine the biolumines- cence of 15 luxA-positive Chesapeake Bay isolates. The instrument, rated by the manufacturer as su⁄ciently sen- sitive...

  7. Communities recognition in the Chesapeake Bay ecosystem by dynamical clustering algorithms based on different oscillators systems

    CERN Document Server

    Pluchino, Alessandro; Latora, Vito

    2008-01-01

    We have recently introduced an efficient method for the detection and identification of modules in complex networks, based on the de-synchronization properties (dynamical clustering) of phase oscillators. In this paper we apply the dynamical clustering tecnique to the identification of communities of marine organisms living in the Chesapeake Bay food web. We show that our algorithm is able to perform a very reliable classification of the real communities existing in this ecosystem by using different kinds of dynamical oscillators. We compare also our results with those of other methods for the detection of community structures in complex networks.

  8. Tidal Marshes across a Chesapeake Bay Subestuary Are Not Keeping up with Sea-Level Rise

    OpenAIRE

    Beckett, Leah H.; Baldwin, Andrew H.; Kearney, Michael S

    2016-01-01

    Sea-level rise is a major factor in wetland loss worldwide, and in much of Chesapeake Bay (USA) the rate of sea-level rise is higher than the current global rate of 3.2 mm yr-1 due to regional subsidence. Marshes along estuarine salinity gradients differ in vegetation composition, productivity, decomposition pathways, and sediment dynamics, and may exhibit different responses to sea-level rise. Coastal marshes persist by building vertically at rates at or exceeding regional sea-level rise. In...

  9. The Chesapeake Bay Impact Crater: An Educational Investigation for Students into the Planetary Impact Process and its Environmental Consequences

    Science.gov (United States)

    Levine, Arlene S.

    2008-01-01

    Planetary impact craters are a common surface feature of many planetary bodies, including the Earth, the Moon, Mars, Mercury, Venus, and Jupiter s moons, Ganymede and Callisto. The NASA Langley Research Center in Hampton, VA, is located about 5 km inside the outer rim of the Chesapeake Bay Impact Crater. The Chesapeake Bay Impact Crater, with a diameter of 85 km is the sixth largest impact crater on our planet. The U.S. Geological Survey (USGS), in collaboration with the NASA Langley Research Center, the Virginia Department of Environmental Quality (VDEQ), the Hampton Roads Planning District Commission (HRPDC), and the Department of Geology of the College of William and Mary (WM) drilled into and through the crater at the NASA Langley Research Center and obtained a continuous core to a depth of 2075.9 ft (632.73 meters) from the Chesapeake Bay Impact Crater. At the NASA Langley location, the granite basement depth was at 2046 ft (623.87 meters). This collaborative drilling activity provided a unique educational opportunity and ongoing educational partnership between USGS, NASA Langley and the other collaborators. NASA Langley has a decade-long, ongoing educational partnership with the Colonial Coast Council of the Girl Scouts. The core drilling and on site analysis and cataloguing of the core segments provided a unique opportunity for the Girl Scouts to learn how geologists work in the field, their tools for scientific investigation and evaluation, how they perform geological analyses of the cores in an on-site tent and learn about the formation of impact craters and the impact of impacting bodies on the sub-surface, the surface, the oceans and atmosphere of the target body. This was accomplished with a two-part activity. Girl Scout day camps and local Girl Scout troops were invited to Langley Research Center Conference Center, where more than 300 Girl Scouts, their leaders and adult personnel were given briefings by scientists and educators from the USGS, NASA

  10. Methylmercury Cycling and Tidal Exchange in a Chesapeake Bay Salt Marsh (Invited)

    Science.gov (United States)

    Mitchell, C. P.; Jordan, T. E.; Heyes, A.; Gilmour, C. C.

    2010-12-01

    The importance of salt marshes to methylmercury budgets in coastal regions is poorly understood. Given that salt marshes are important coastal features around Chesapeake Bay and in many other coastal areas, and that methylmercury is a bioaccumulated neurotoxin to aquatic biota and the humans that consume them, fully understanding methylmercury sources is an important step in mitigating detrimental health and ecosystem effects. In this research, we highlight the important biogeochemical controls on methylmercury production in a Chesapeake Bay salt marsh and link this production with tidal exchange using hydrological measurements and sampling over a 12-month period. Our findings point to an important linkage between iron cycling and methylmercury production. Net tidal exchange of total mercury and methylmercury showed marked seasonal variation, especially for methylmercury. Overall, we estimate the salt marsh was a large net sink for total mercury (~60 μg m-2 yr-1) and a net source of methylmercury (~0.25 μg m-2 yr-1). In addition to significant in situ methylmercury exposure risk to biota that utilize salt marshes as habitat or breeding grounds, the contribution of methylmercury to the estuarine zone as a result of salt marsh tidal exchange is not negligible.

  11. Diet selectivity of juvenile blue crabs (Callinectes sapidus) in Chesapeake Bay.

    Science.gov (United States)

    Seitz, Rochelle D; Knick, Kathleen E; Westphal, Miranda

    2011-10-01

    Shallow coves in Chesapeake Bay have abundant food and serve as nursery grounds for juvenile blue crabs. In this study, we examined the relationships between the diet of very small (4-40 mm CW) juvenile blue crabs and the benthic infauna in shallow, unvegetated nursery coves. We compared infauna in benthic samples with gut contents of juvenile blue crabs from six shallow coves in each of two sub-estuaries (Rappahannock and York Rivers) in Chesapeake Bay, Virginia, USA. Benthic communities differed depending on river and location, with abundant clams in upriver regions and abundant polychaetes in downriver regions. Juvenile crabs, like adults, appeared to be opportunistic feeders, with gut contents including clams, amphipods, polychaetes, small crustaceans, plant matter, and detritus. There was a positive relationship between polychaetes in the benthic samples and in crab guts, suggesting that juvenile crabs are opportunistic feeders on polychaetes in the benthos. Moreover, Ivlev's electivity index and foraging ratio showed that clams and polychaetes were selectively eaten at all locations. Alternatively, crabs selectively rejected amphipods. Crab densities corresponded positively with polychaete densities, which suggests that there may be bottom-up control of crab distributions and that food resources are important in nursery habitats.

  12. Reconstructing the rise of recent coastal anoxia; molybdenum in Chesapeake Bay sediments

    Science.gov (United States)

    Adelson, J.M.; Helz, G.R.; Miller, C.V.

    2001-01-01

    Sporadic, direct observations over a 50 yr period inadequately characterize the history of seasonal hypoxia and anoxia in Chesapeake Bay, alarge estuary threatened by eutrophication. Here, we undertake a reconstruction of 20th century oxygen depletion in this estuary using Mo concentrations in 210Pb-dated sediments; Cu concentrations are used to control for anthropogenic influences. Cores from the central channel display mild Mo enrichments above crustal backgrounds (up to 5 ??g/g) and strong Cu enrichments (up to 35 ??g/g). Temporally, Cu enrichment (mostly anthropogenic) began earlier and stabilized in the last two thirds of the 20th century. In contrast, Mo enrichment has grown during the last two thirds of the century. Molybdenum enrichment is mostly hydrogenic, except in a section of the channel that receives additional Mo from erosion of Early Miocene shore deposits. Two geochemical mechanisms promote Mo enrichment: Manganese refluxing concentrates dissolved MoO24- at the sediment-water interface and sulfide substitution into MoO24- produces thiomolybdates, which can be fixed by particles. The Mo enrichment mechanisms operate primarily during periods when bottom waters are anoxic and thiomolybdate formation can occur near the sediment-water interface. This implies a temporal coupling between water-column anoxia and Mo fixation even though fixation occurs only within sediments. The Mo enrichment profiles suggest that Chesapeake Bay has experienced growing O2 depletion since the first half of the 20th century, but especially after 1960. Copyright ?? 2001 Elsevier Science Ltd.

  13. Interrogation of Chesapeake Bay sediment microbial communities for intrinsic alkane-utilizing potential under anaerobic conditions.

    Science.gov (United States)

    Johnson, Jamie M; Wawrik, Boris; Isom, Catherine; Boling, Wilford B; Callaghan, Amy V

    2015-02-01

    Based on the transient exposure of Chesapeake Bay sediments to hydrocarbons and the metabolic versatility of known anaerobic alkane-degrading microorganisms, it was hypothesized that distinct Bay sediment communities, governed by geochemical gradients, would have intrinsic alkane-utilizing potential under sulfate-reducing and/or methanogenic conditions. Sediment cores were collected along a transect of the Bay. Community DNA was interrogated via pyrosequencing of 16S rRNA genes, PCR of anaerobic hydrocarbon activation genes, and qPCR of 16S rRNA genes and genes involved in sulfate reduction/methanogenesis. Site sediments were used to establish microcosms amended with n-hexadecane under sulfate-reducing and methanogenic conditions. Sequencing of 16S rRNA genes indicated that sediments associated with hypoxic water columns contained significantly greater proportions of Bacteria and Archaea consistent with syntrophic degradation of organic matter and methanogenesis compared to less reduced sediments. Microbial taxa frequently associated with hydrocarbon-degrading communities were found throughout the Bay, and the genetic potential for hydrocarbon metabolism was demonstrated via the detection of benzyl-(bssA) and alkylsuccinate synthase (assA) genes. Although microcosm studies did not indicate sulfidogenic alkane degradation, the data suggested that methanogenic conversion of alkanes was occurring. These findings highlight the potential role that anaerobic microorganisms could play in the bioremediation of hydrocarbons in the Bay.

  14. Multi-band algorithms for the estimation of chlorophyll concentration in the Chesapeake Bay

    KAUST Repository

    Gilerson, Alexander

    2015-10-14

    Standard blue-green ratio algorithms do not usually work well in turbid productive waters because of the contamination of the blue and green bands by CDOM absorption and scattering by non-algal particles. One of the alternative approaches is based on the two- or three band ratio algorithms in the red/NIR part of the spectrum, which require 665, 708, 753 nm bands (or similar) and which work well in various waters all over the world. The critical 708 nm band for these algorithms is not available on MODIS and VIIRS sensors, which limits applications of this approach. We report on another approach where a combination of the 745nm band with blue-green-red bands was the basis for the new algorithms. A multi-band algorithm which includes ratios Rrs(488)/Rrs(551)and Rrs(671)/Rrs(745) and two band algorithm based on Rrs671/Rrs745 ratio were developed with the main focus on the Chesapeake Bay (USA) waters. These algorithms were tested on the specially developed synthetic datasets, well representing the main relationships between water parameters in the Bay taken from the NASA NOMAD database and available literature, on the field data collected by our group during a 2013 campaign in the Bay, as well as NASA SeaBASS data from the other group and on matchups between satellite imagery and water parameters measured by the Chesapeake Bay program. Our results demonstrate that the coefficient of determination can be as high as R2 > 0.90 for the new algorithms in comparison with R2 = 0.6 for the standard OC3V algorithm on the same field dataset. Substantial improvement was also achieved by applying a similar approach (inclusion of Rrs(667)/Rrs(753) ratio) for MODIS matchups. Results for VIIRS are not yet conclusive. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  15. 33 CFR 165.502 - Safety and Security Zone; Cove Point Liquefied Natural Gas Terminal, Chesapeake Bay, Maryland.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety and Security Zone; Cove Point Liquefied Natural Gas Terminal, Chesapeake Bay, Maryland. 165.502 Section 165.502 Navigation and... Areas Fifth Coast Guard District § 165.502 Safety and Security Zone; Cove Point Liquefied Natural...

  16. 33 CFR 334.370 - Chesapeake Bay, Lynnhaven Roads; danger zones, U.S. Naval Amphibious Base.

    Science.gov (United States)

    2010-07-01

    ...; danger zones, U.S. Naval Amphibious Base. 334.370 Section 334.370 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.370 Chesapeake Bay, Lynnhaven Roads; danger zones, U.S. Naval Amphibious Base....

  17. 33 CFR 165.505 - Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland. 165.505 Section 165.505 Navigation and... Areas Fifth Coast Guard District § 165.505 Security Zone; Calvert Cliffs Nuclear Power Plant,...

  18. Scientific Personnel Resource Inventory: List and Index to Research Scientists Involved with the Estuarine Environment, Especially the Chesapeake Bay,

    Science.gov (United States)

    1972-06-01

    including systematics, distribution, and evolution of Pereidae, Hemicamphidae, Belonidae, and Scombridae I -27- NLA I llier, Ries Stuart MS Fishery...invertebrates, especially Kinorhyncha, Priapulida and Tardigrada (24 5Higman, Daniel MS Botanist Chesapeake Bay Center for Environmental Studies Smithsonian...2111 ext.65 B-4, B-5, Community ecology -- Fisheries biology, including community ecology, behavior and systematics -- Zoogeography -- Evolution 406

  19. 33 CFR 334.380 - Atlantic Ocean south of entrance to Chesapeake Bay off Dam Neck, Virginia; naval firing range.

    Science.gov (United States)

    2010-07-01

    ... to Chesapeake Bay off Dam Neck, Virginia; naval firing range. 334.380 Section 334.380 Navigation and..., Virginia; naval firing range. (a) The danger zone. All of the water within a sector extending seaward a...) nautical miles. (3) Firing on the ranges will be suspended as long as any vessel is within the danger...

  20. Uncertainty in model predictions of Vibrio vulnificus response to climate variability and change: a Chesapeake Bay case study.

    Directory of Open Access Journals (Sweden)

    Erin A Urquhart

    Full Text Available The effect that climate change and variability will have on waterborne bacteria is a topic of increasing concern for coastal ecosystems, including the Chesapeake Bay. Surface water temperature trends in the Bay indicate a warming pattern of roughly 0.3-0.4°C per decade over the past 30 years. It is unclear what impact future warming will have on pathogens currently found in the Bay, including Vibrio spp. Using historical environmental data, combined with three different statistical models of Vibrio vulnificus probability, we explore the relationship between environmental change and predicted Vibrio vulnificus presence in the upper Chesapeake Bay. We find that the predicted response of V. vulnificus probability to high temperatures in the Bay differs systematically between models of differing structure. As existing publicly available datasets are inadequate to determine which model structure is most appropriate, the impact of climatic change on the probability of V. vulnificus presence in the Chesapeake Bay remains uncertain. This result points to the challenge of characterizing climate sensitivity of ecological systems in which data are sparse and only statistical models of ecological sensitivity exist.

  1. Societal Implications of an Impact Crater - Chesapeake Bay Impact Structure, Virginia

    Science.gov (United States)

    Emry, S.; McFarland, R.; Powars, D.

    2002-05-01

    Ground water plays an important role in the economy and quality of life in the Coastal Plain of Virginia. In 1990, the aquifers in the Coastal Plain supplied over 100 million gallons of water per day to the citizens, businesses, and industries of Virginia. In southeastern Virginia, the thirteen public water utilities serve approximately 1.5 million people in the Hampton Roads area. The role of ground water resources in sustaining this area is more critical than ever due to the relatively low relief of the Coastal Plain Province, providing few new surface water sources to meet the growing population and expanding economy and the increased regulatory obstacles to obtaining a permit to build new reservoirs. A zone of salty ground water, referred to as the "inland salt water wedge," is well known to ground water resource planners and scientists, but until recently the phenomenon has not been satisfactorily explained. In 1996, the directors of the water utilities in Hampton Roads were introduced to the most dramatic geological event that ever took place in the Chesapeake Bay region. Geologists from the U.S. Geological Survey provided evidence of a meteor impact that formed a crater over 35 million years ago. The contours of the inland saltwater wedge conform well to the shape of the crater's outer rim. Prior to the discovery of the impact crater, it was presumed that the ground water flow in the Coastal Plain aquifer system was a relatively simple system described as "alternating layers of aquifers and confining units gradually dipping and thickening from the west to the east." With the discovery of the impact crater, the rules changed. In 1997, the USGS and the Hampton Roads Planning District Commission, representing the sixteen member jurisdictions, teamed up in a cooperative effort to redefine the hydrogeology of southeastern Virginia. In 1999, the Virginia Department of Environmental Quality and the Virginia Department of Mines, Minerals, and Energy joined the team

  2. NOAA Office for Coastal Management Benthic Habitat Data, Catlett and Goodwin Islands on the York River in Chesapeake Bay, VA, 2002-2004 (NODC Accession 0090253)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are a collection of benthic habitat data from studies conducted in the Catlett and Goodwin Islands on the York River in Chesapeake Bay, Virginia in GIS...

  3. Long-term decline in the calanoid copepod Acartia tonsa in central Chesapeake Bay, USA: An indirect effect of eutrophication?

    Science.gov (United States)

    Kimmel, David G.; Boynton, Walter R.; Roman, Michael R.

    2012-04-01

    A long-term abundance record of the calanoid copepod Acartia tonsa in the Maryland portion of Chesapeake Bay was compiled from 1966 to 2002. A significant downward trend in the summertime abundance of Acartia tonsa was found in central Chesapeake Bay. We propose that environmental and food web changes occurred as the Chesapeake Bay became increasingly impacted by human activity which eventually led to the overall decline of A. tonsa. Environmental changes included a long-term rise in water temperature and the volume of hypoxic water during the summer. These changes occurred during the same time period as increases in chlorophyll a concentration, declines in the landings of the eastern oyster Crassostrea virginica, and declines in abundance of the sea nettle Chrysaora quinquecirrha. A CUSUM analysis showed that each time-series experienced a change point during over the past 50 years. These changes occurred sequentially, with chlorophyll a concentration increasing beginning in 1969, water temperature and hypoxic volume increasing beginning in the early 1980s, more recent Maryland C. virginica landings begin declining in the early 1980s and A. tonsa and C. quinquecirrha declining starting in 1989. A stepwise regression analysis revealed that the reduction in A. tonsa abundance appeared to be most associated with a decreasing trend in C. quinquecirrha abundance, though only when trends in the two time-series were present. The drop in C. quinquecirrha abundance is associated with reduced predation on the ctenophore, Mnemiopsis leidyi, a key predator of A. tonsa. The long-term decline of A. tonsa has likely impacted trophic transfer to fish, particularly the zooplanktivorous bay anchovy (Anchoa mitchilli). A time-series of bay anchovy juvenile index showed a negative trend and the CUSUM analysis revealed 1993 as its starting point. Total fisheries landings, excluding menhaden (Brevoortia tyrannus), in Chesapeake Bay have also declined during the same period and this

  4. Radionuclide distributions and sorption behavior in the Susquehanna--Chesapeake Bay System

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, C.R.; Larsen, I.L.; Lowry, P.D.; McLean, R.I.; Domotor, S.L.

    1989-01-01

    Radionuclides released into the Susquehanna--Chesapeake System from the Three Mile Island, Peach Bottom, and Calvert Cliffs nuclear power plants are partitioned among dissolved, particulate, and biological phases and may thus exist in a number of physical and chemical forms. In this project, we have measured the dissolved and particulate distributions of fallout /sup 137/Cs; reactor-released /sup 137/Cs, /sup 134/Cs, /sup 65/Zn, /sup 60/Co, and /sup 58/Co; and naturally occurring /sup 7/Be and /sup 210/Pb in the lower Susquehanna River and Upper Chesapeake Bay. In addition, we chemically leached suspended particles and bottom sediments in the laboratory to determine radionuclide partitioning among different particulate-sorbing phases to complement the site-specific field data. This information has been used to document the important geochemical processes that affect the transport, sorption, distribution, and fate of reactor-released radionuclides (and by analogy, other trace contaminants) in this river-estuarine system. Knowledge of the mechanisms, kinetic factors, and processes that affect radionuclide distributions is crucial for predicting their biological availability, toxicity, chemical behavior, physical transport, and accumulation in aquatic systems. The results from this project provide the information necessary for developing accurate radionuclide-transport and biological-uptake models. 76 refs., 12 figs.

  5. Evidence for high salinity of Early Cretaceous sea water from the Chesapeake Bay crater.

    Science.gov (United States)

    Sanford, Ward E; Doughten, Michael W; Coplen, Tyler B; Hunt, Andrew G; Bullen, Thomas D

    2013-11-14

    High-salinity groundwater more than 1,000 metres deep in the Atlantic coastal plain of the USA has been documented in several locations, most recently within the 35-million-year-old Chesapeake Bay impact crater. Suggestions for the origin of increased salinity in the crater have included evaporite dissolution, osmosis and evaporation from heating associated with the bolide impact. Here we present chemical, isotopic and physical evidence that together indicate that groundwater in the Chesapeake crater is remnant Early Cretaceous North Atlantic (ECNA) sea water. We find that the sea water is probably 100-145 million years old and that it has an average salinity of about 70 per mil, which is twice that of modern sea water and consistent with the nearly closed ECNA basin. Previous evidence for temperature and salinity levels of ancient oceans have been estimated indirectly from geochemical, isotopic and palaeontological analyses of solid materials in deep sediment cores. In contrast, our study identifies ancient sea water in situ and provides a direct estimate of its age and salinity. Moreover, we suggest that it is likely that remnants of ECNA sea water persist in deep sediments at many locations along the Atlantic margin.

  6. Community implementation dynamics: Nutrient management in the New York City and Chesapeake Bay Watersheds

    Directory of Open Access Journals (Sweden)

    Glenn Earl Sterner

    2015-04-01

    Full Text Available The creation of natural resource management and conservation strategies can be affected by engagement with local citizens and competing interests between agencies and stakeholders at the varying levels of governance. This paper examines the role of local engagement and the interaction between governance levels on the outcomes of nutrient management policy, a specific area of natural resource conservation and management. Presented are two case studies of the New York City and Chesapeake Bay Watersheds in the US. These case studies touch upon the themes of local citizen engagement and governance stakeholder interaction in changing nutrient management to improve water quality. An analysis of these cases leads to several key considerations for the creation and implementation of nutrient management and natural resource management more broadly, including the importance of: local citizen engagement, government brokering and cost sharing; and the need of all stakeholders to respect each other in the policy creation and implementation process.

  7. Medieval Warm Period, Little Ice Age and 20th century temperature variability from Chesapeake Bay

    Science.gov (United States)

    Cronin, T. M.; Dwyer, G.S.; Kamiya, T.; Schwede, S.; Willard, D.A.

    2003-01-01

    We present paleoclimate evidence for rapid (changes in the strength of North Atlantic thermohaline circulation (THC). Evidence is presented for a long period of sustained regional and North Atlantic-wide warmth with low-amplitude temperature variability between ~450 and 1000 AD. In addition to centennial-scale temperature shifts, the existence of numerous temperature maxima between 2200 and 250 years BP (average ~70 years) suggests that multi-decadal processes typical of the North Atlantic Oscillation (NAO) are an inherent feature of late Holocene climate. However, late 19th and 20th century temperature extremes in Chesapeake Bay associated with NAO climate variability exceeded those of the prior 2000 years, including the interval 450-1000 AD, by 2-3oC, suggesting anomalous recent behavior of the climate system.

  8. Climate Change and the Evolution and Fate of the Tangier Islands of Chesapeake Bay, USA

    Science.gov (United States)

    Schulte, David M.; Dridge, Karin M.; Hudgins, Mark H.

    2015-12-01

    Climate change and associated sea level rise (SLR) are already impacting low-lying coastal areas, including islands, throughout the world. Many of these areas are inhabited, many will need to be abandoned in coming decades as SLR continues. We examine the evolution (1850-2013) of the last inhabited offshore island in Virginia waters of Chesapeake Bay USA, the Tangier Islands. Three SLR scenarios, a low, mid, and high, were considered. Since 1850, 66.75% of the islands landmass has been lost. Under the mid-range SLR scenario, much of the remaining landmass is expected to be lost in the next 50 years and the Town will likely need to be abandoned. The high SLR scenario will accelerate the land loss and subsidence, such that the Town may need to be abandoned in as few as 25 years. We propose a conceptual plan that would significantly extend the lifespan of the islands and Town.

  9. Evaluation of ERTS MSS digital data for monitoring water in the lower Chesapeake Bay area

    Science.gov (United States)

    Bowker, D. E.; Witte, W. G.

    1975-01-01

    Water samples collected during the ERTS overpasses of the lower Chesapeake Bay area have been analyzed for chlorophyll, particles, and sediment. Five ERTS images were sufficiently cloud free that a correlation analysis of radiance values from the MSS bands with the water parameters could be performed. A low correlation was established for chlorophyll, except during algal blooms, when band 6 was responsive. There was a fair to good correlation with particles for combinations of band 5, particularly bands (5 minus 6). Sediment correlations were excellent for band 5 or combinations of band 5 with bands 4 and 6. It was evident that such factors as the atmosphere, tide, and different water masses were tending to confuse the data.

  10. Chesapeake Bay nutrient pollution: contribution from the land application of sewage sludge in Virginia.

    Science.gov (United States)

    Land, Lynton S

    2012-11-01

    Human health concerns and the dissemination of anthropogenic substances with unknown consequences are the reasons most often given why disposal of municipal sewage sludge in landfills or using the organic waste as biofuel is preferable to land application. But no "fertilizer" causes more nitrogen pollution than sludge when applied according to Virginia law. Poultry litter is the only other "fertilizer" that causes more phosphorus pollution than sludge. Cost savings by the few farmers in Virginia who use sludge are far less than the costs of the nitrogen pollution they cause. A ban on the land application of all forms of animal waste is very cost-effective and would reduce Chesapeake Bay nutrient pollution by 25%. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Communities recognition in the Chesapeake Bay ecosystem by dynamical clustering algorithms based on different oscillators systems

    Science.gov (United States)

    Pluchino, A.; Rapisarda, A.; Latora, V.

    2008-10-01

    We have recently introduced [Phys. Rev. E 75, 045102(R) (2007); AIP Conference Proceedings 965, 2007, p. 323] an efficient method for the detection and identification of modules in complex networks, based on the de-synchronization properties (dynamical clustering) of phase oscillators. In this paper we apply the dynamical clustering tecnique to the identification of communities of marine organisms living in the Chesapeake Bay food web. We show that our algorithm is able to perform a very reliable classification of the real communities existing in this ecosystem by using different kinds of dynamical oscillators. We compare also our results with those of other methods for the detection of community structures in complex networks.

  12. Community implementation dynamics: Nutrient management in the New York City and Chesapeake Bay Watersheds

    Directory of Open Access Journals (Sweden)

    Glenn Earl Sterner

    2015-04-01

    Full Text Available The creation of natural resource management and conservation strategies can be affected by engagement with local citizens and competing interests between agencies and stakeholders at the varying levels of governance. This paper examines the role of local engagement and the interaction between governance levels on the outcomes of nutrient management policy, a specific area of natural resource conservation and management. Presented are two case studies of the New York City and Chesapeake Bay Watersheds in the US. These case studies touch upon the themes of local citizen engagement and governance stakeholder interaction in changing nutrient management to improve water quality. An analysis of these cases leads to several key considerations for the creation and implementation of nutrient management and natural resource management more broadly, including the importance of: local citizen engagement, government brokering and cost sharing; and the need of all stakeholders to respect each other in the policy creation and implementation process.

  13. The bioeconomic impact of different management regulations on the Chesapeake Bay blue crab fishery

    Science.gov (United States)

    Bunnell, David B.; Lipton, Douglas W.; Miller, Thomas J.

    2010-01-01

    The harvest of blue crabs Callinectes sapidus in Chesapeake Bay declined 46% between 1993 and 2001 and remained low through 2008. Because the total market value of this fishery has declined by an average of US $ 3.3 million per year since 1993, the commercial fishery has been challenged to maintain profitability. We developed a bioeconomic simulation model of the Chesapeake Bay blue crab fishery to aid managers in determining which regulations will maximize revenues while ensuring a sustainable harvest. We compared 15 different management scenarios, including those implemented by Maryland and Virginia between 2007 and 2009, that sought to reduce female crab harvest and nine others that used seasonal closures, different size regulations, or the elimination of fishing for specific market categories. Six scenarios produced the highest revenues: the 2008 and 2009 Maryland regulations, spring and fall closures for female blue crabs, and 152- and 165-mm maximum size limits for females. Our most important finding was that for each state the 2008 and 2009 scenarios that implemented early closures of the female crab fishery produced higher revenues than the 2007 scenario, in which no early female closures were implemented. We conclude that the use of maximum size limits for female crabs would not be feasible despite their potentially high revenue, given the likelihood that the soft-shell and peeler fisheries cannot be expanded beyond their current capacity and the potentially high mortality rate for culled individuals that are the incorrect size. Our model results support the current use of seasonal closures for females, which permit relatively high exploitation of males and soft-shell and peeler blue crabs (which have high prices) while keeping the female crab harvest sustainable. Further, our bioeconomic model allows for the inclusion of an economic viewpoint along with biological data when target reference points are set by managers.

  14. Metal concentrations in oldsquaw (Clangula hyemalis) during an outbreak of avian cholera, Chesapeake Bay, 1994

    Science.gov (United States)

    Mashima, T.Y.; Fleming, W.J.; Stoskopf, M.K.

    1998-01-01

    Forty out of 41 oldsquaw carcasses collected during a 3 month avian cholera outbreak in Chesapeake Bay, USA, in 1994 were culture positive for Pasteurella multocida. Pasteurella-positive birds collected in February had greater (p ??? 0.05) mean (geometric) liver concentrations of cadmium (7.35 versus 3.71 ??g per g dry weight) and lower concentrations of selenium (9.90 versus 12.5 ??g per g dry weight) than Pasteurella-positive birds collected during March and April. The mercury content of the livers and cadmium content of the kidneys did not differ (p > 0.05) between birds collected early in the die-off and those collected in March and April. The liver and kidney concentrations of metals in the Pasteurella-positive birds collected in 1994 were compared to apparently healthy oldsquaw (n = 67) collected from Chesapeake Bay during 1985-1987, because healthy oldsquaw were not collected during the avian cholera outbreak in 1994. Compared to the apparently healthy oldsquaw collected in 1985-1987, the mean concentrations of cadmium (liver 4.32 versus 2.65 ??g per g dry weight and kidney 22.7 versus 11.5 ??g per g dry weight) were greater (p ??? 0.05) in the oldsquaw which succumbed to avian cholera in 1994. In contrast, the liver concentrations of selenium (11.9 versus 17.8 ??g per g dry weight) and mercury (0.389 versus 1.83 ??g per g dry weight) were lower (p ??? 0.05) in the birds from the 1994 die-off than for the apparently healthy oldsquaw collected in 1985-1987. Three birds from the 1985-1987 cohort and none of the birds from the 1994 cohort had liver lead concentrations greater than 4 ??g per g dry weight. The results of this study indicate a possible link between high cadmium tissue concentrations and susceptibility to avian cholera in oldsquaw.

  15. Island abandonment and sea-level rise: an historical analog from the Chesapeake Bay, USA

    Energy Technology Data Exchange (ETDEWEB)

    Gibbons, S.J.A. [Wilfrid Laurier University, Waterloo (Canada). Dept. of Geography and Enivronmental Studies; Nicholls, R.J. [University of Southampton (United Kingdom). School of Civil Engineering

    2006-02-15

    Small islands are widely agreed to be vulnerable to human-induced sea-level rise during the 21st century and beyond, with forced abandonment of some low-lying oceanic islands being a real possibility. A regional abandonment of islands in the Chesapeake Bay, USA provides an historical analog of such vulnerability as this has been linked to a mid 19th Century acceleration in relative sea-level rise. Using a case study approach for Holland Island, Maryland, this hypothesis was tested using a range of physical and human historical data. While sea-level rise was the underlying driver, this analysis shows that the abandonment was more complex than a direct response to sea-level rise. Between 1850 and 1900, Holland Island was a booming community and population increased from 37 to 253, with immigration causing the majority of the increase. At the same time, the upland area where people made their homes was steadily diminishing, losing about 15 ha or 38% of the total. After 1900, the island experienced a decrease in population to 169 in 1916, with final abandonment in 1918, with the exception of one family who left by 1920. Final abandonment was triggered by this depopulation as the population fell below a level that could support critical community services, and the community lost faith in their future on Holland Island. It is likely that similar social processes determined the abandonment of the other Chesapeake Bay islands. Looking to the future, it shows that many small low-lying islands could be abandoned due to sea-level rise long before they become physically uninhabitable. (author)

  16. Reproductive health of yellow perch Perca flavescens in selected tributaries of the Chesapeake Bay

    Energy Technology Data Exchange (ETDEWEB)

    Blazer, Vicki S., E-mail: Vblazer@usgs.gov [U.S. Geological Survey, National Fish Health Research Laboratory, Leetown Science Center, 11649 Leetown Road, Kearneysville, WV 25430 (United States); Pinkney, Alfred E., E-mail: Fred_Pinkeny@fws.gov [U.S. Fish and Wildlife Service, Chesapeake Bay Field Office, 177 Admiral Cochrane Drive, Annapolis, MD 21401 (United States); Jenkins, Jill A., E-mail: jenkinsj@usgs.gov [U.S. Geological Survey, National Wetlands Research Center, 700 Cajundome Blvd., Lafayette, LA 70506 (United States); Iwanowicz, Luke R., E-mail: Liwanowicz@usgs.gov [U.S. Geological Survey, National Fish Health Research Laboratory, Leetown Science Center, 11649 Leetown Road, Kearneysville, WV 25430 (United States); Minkkinen, Steven, E-mail: steve_minkkinen@fws.gov [U.S. Fish and Wildlife Service, Chesapeake Bay Field Office, 177 Admiral Cochrane Drive, Annapolis, MD 21401 (United States); Draugelis-Dale, Rassa O., E-mail: daler@usgs.gov [U.S. Geological Survey, National Wetlands Research Center, 700 Cajundome Blvd., Lafayette, LA 70506 (United States); Uphoff, James H., E-mail: juphoff@dnr.state.md.us [Maryland Department of Natural Resources, Fisheries Service, Cooperative Oxford Laboratory, 904 South Morris Street, Oxford, MD 21654 (United States)

    2013-03-01

    Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007–2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations and gonad histology were evaluated in mature perch of both sexes. In addition, sperm quantity (cell counts) and quality (total and progressive motility, spermatogenic stage and DNA integrity), were measured in male perch. Many of these biomarkers varied annually and spatially, with some interesting statistical results and trends. Male perch from the Choptank and Allen's Fresh had generally higher sperm counts. In 2008 counts were significantly lower in the perch from the Severn when compared to other sites. The major microscopic gonadal abnormality in males was the proliferation of putative Leydig cells, observed in testes from Severn and less commonly, Mattawoman Creek perch. Observations that could significantly impact egg viability were an apparent lack of final maturation, abnormal yolk and thin, irregular zona pellucida. These were observed primarily in ovaries from Severn, South and less commonly Mattawoman Creek perch. The potential association of these observations with urbanization, impervious surface and chemical contaminants is discussed. - Highlights: ► Reduced recruitment of yellow perch has occurred in urban tributaries of Chesapeake Bay. ► We compared reproductive health biomarkers in perch from two urban, one developing, two less developed

  17. Nutrient and suspended-sediment trends, loads, and yields and development of an indicator of streamwater quality at nontidal sites in the Chesapeake Bay watershed, 1985-2010

    Science.gov (United States)

    Langland, Michael; Blomquist, Joel; Moyer, Douglas; Hyer, Kenneth

    2012-01-01

    The U.S. Geological Survey (USGS) updates information on loads of, and trends in, nutrients and sediment annually to help the Chesapeake Bay Program (CBP) investigators assess progress toward improving water-quality conditions in the Chesapeake Bay and its watershed. CBP scientists and managers have worked since 1983 to improve water quality in the bay. In 2010, the U.S. Environmental Protection Agency (USEPA) established a Total Maximum Daily Load (TMDL) for the Chesapeake Bay. The TMDL specifies nutrient and sediment load allocations that need to be achieved in the watershed to improve dissolved oxygen, water-clarity, and chlorophyll conditions in the bay. The USEPA, USGS, and state and local jurisdictions in the watershed operate a CBP nontidal water-quality monitoring network and associated database that are used to update load and trend information to help assess progress toward reducing nutrient and sediment inputs to the bay. Data collected from the CBP nontidal network were used to estimate loads and trends for two time periods: a long-term period (1985-2010) at 31 "primary" sites (with storm sampling) and a 10-year period (2001-10) at 33 primary sites and 16 "secondary" sites (without storm sampling). In addition, loads at 64 primary sites were estimated for the period 2006 to 2010. Results indicate improving flow-adjusted trends for nitrogen and phosphorus for 1985 to 2010 at most of the sites in the network. For nitrogen, 21 of the 31 sites showed downward (improving) trends, whereas 2 sites showed upward (degrading) trends, and 8 sites showed no trends. The results for phosphorus were similar: 22 sites showed improving trends, 4 sites showed degrading trends, and 5 sites indicated no trends. For sediment, no trend was found at 40 percent of the sites, with 10 sites showing improving trends and 8 sites showing degrading trends. The USGS, working with CBP partners, developed a new water-quality indicator that combines the results of the 10-year trend

  18. Comparison of two regression-based approaches for determining nutrient and sediment fluxes and trends in the Chesapeake Bay watershed

    Science.gov (United States)

    Moyer, Douglas; Hirsch, Robert M.; Hyer, Kenneth

    2012-01-01

    Nutrient and sediment fluxes and changes in fluxes over time are key indicators that water resource managers can use to assess the progress being made in improving the structure and function of the Chesapeake Bay ecosystem. The U.S. Geological Survey collects annual nutrient (nitrogen and phosphorus) and sediment flux data and computes trends that describe the extent to which water-quality conditions are changing within the major Chesapeake Bay tributaries. Two regression-based approaches were compared for estimating annual nutrient and sediment fluxes and for characterizing how these annual fluxes are changing over time. The two regression models compared are the traditionally used ESTIMATOR and the newly developed Weighted Regression on Time, Discharge, and Season (WRTDS). The model comparison focused on answering three questions: (1) What are the differences between the functional form and construction of each model? (2) Which model produces estimates of flux with the greatest accuracy and least amount of bias? (3) How different would the historical estimates of annual flux be if WRTDS had been used instead of ESTIMATOR? One additional point of comparison between the two models is how each model determines trends in annual flux once the year-to-year variations in discharge have been determined. All comparisons were made using total nitrogen, nitrate, total phosphorus, orthophosphorus, and suspended-sediment concentration data collected at the nine U.S. Geological Survey River Input Monitoring stations located on the Susquehanna, Potomac, James, Rappahannock, Appomattox, Pamunkey, Mattaponi, Patuxent, and Choptank Rivers in the Chesapeake Bay watershed. Two model characteristics that uniquely distinguish ESTIMATOR and WRTDS are the fundamental model form and the determination of model coefficients. ESTIMATOR and WRTDS both predict water-quality constituent concentration by developing a linear relation between the natural logarithm of observed constituent

  19. Impacts of land cover changes on hurricane storm surge in the lower Chesapeake Bay

    Science.gov (United States)

    Denton, M.; Lawler, S.; Ferreira, C.

    2013-12-01

    The Chesapeake Bay is the largest estuary in the United States with more than 150 rivers draining into the bay's tidal wetlands. Coastal wetlands and vegetation play an important role in shaping the hydrodynamics of storm surge events by retaining water and slowing the propagation of storm surge. In this way coastal wetlands act as a natural barrier to inland flooding, particularly against less intense storms. Threats to wetlands come from both land development (residential or commercial/industrial) and sea level rise. The lower region of the Chesapeake Bay near its outlet is especially vulnerable to flooding from Atlantic storm surge brought in by hurricanes, tropical storms and nor'easters (e.g., hurricanes Isabel [2003] and Sandy [2012]). This region is also intensely developed with nearly 1.7 million residents within the greater Hampton Roads metropolitan area. Anthropogenic changes to land cover in the lower bay can directly impact basin drainage and storm surge propagation with impacts reaching beyond the immediate coastal zone to affect flooding in inland areas. While construction of seawall barriers around population centers may provide storm surge protection to a specifically defined area, these barriers deflect storm surge rather than attenuate it, underscoring the importance of wetlands. To analyze these impacts a framework was developed combining numerical simulations with a detailed hydrodynamic characterization of flow through coastal wetland areas. Storm surges were calculated using a hydrodynamic model (ADCIRC) coupled to a wave model (SWAN) forced by an asymmetric hurricane vortex model using the FEMA region 3 unstructured mesh (2.3 million nodes) under a High Performance Computing (HPC) environment. Multiple model simulations were performed using historical hurricanes data and hypothetical storms to compare the predicted storm surge inundation with various levels of wetland reduction and/or beach hardening. These data were combined and overlaid

  20. Responses of selected Chesapeake Bay fish and invertebrate species to natural and artificial thermal increases - a review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Liden, L.H.; Burton, D.T.

    1978-01-01

    A review of the biological literature concerning the acute effects of thermal increases upon several fish and invertebrate species indigenous to the Chesapeake Bay was conducted. The acute effects data were combined with other natural life-temperature interaction data for developmental stages of Pseudopleuronectes americanus, Morone saxatalis, Leiostomus xanthurus, Micropogon undulatus, Menidia menidia, Anchoa mitchilli, Brevoortia tyrannus and Crassostrea virginica and Callinectes sapidus. The data were evaluated to ascertain what effects, if any, the thermal discharge (5.6C maximum delta T) from Calvert Cliffs Nuclear Power Plant would have upon populations of these species in the Chesapeake Bay. It was concluded from the data that a thermal discharge such as that from Calvert Cliffs would have little or no impact upon the egg, larval, juvenile or adult populations of the studied species.

  1. Forecasting hypoxia in the Chesapeake Bay and Gulf of Mexico: model accuracy, precision, and sensitivity to ecosystem change

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Mary Anne; Scavia, Donald, E-mail: mevans@umich.edu, E-mail: scavia@umich.edu [School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI 48109 (United States)

    2011-01-15

    Increasing use of ecological models for management and policy requires robust evaluation of model precision, accuracy, and sensitivity to ecosystem change. We conducted such an evaluation of hypoxia models for the northern Gulf of Mexico and Chesapeake Bay using hindcasts of historical data, comparing several approaches to model calibration. For both systems we find that model sensitivity and precision can be optimized and model accuracy maintained within reasonable bounds by calibrating the model to relatively short, recent 3 year datasets. Model accuracy was higher for Chesapeake Bay than for the Gulf of Mexico, potentially indicating the greater importance of unmodeled processes in the latter system. Retrospective analyses demonstrate both directional and variable changes in sensitivity of hypoxia to nutrient loads.

  2. Attenuation of Storm Surge Flooding By Wetlands in the Chesapeake Bay: An Integrated Geospatial Framework Evaluating Impacts to Critical Infrastructure

    Science.gov (United States)

    Khalid, A.; Haddad, J.; Lawler, S.; Ferreira, C.

    2014-12-01

    Areas along the Chesapeake Bay and its tributaries are extremely vulnerable to hurricane flooding, as evidenced by the costly effects and severe impacts of recent storms along the Virginia coast, such as Hurricane Isabel in 2003 and Hurricane Sandy in 2012. Coastal wetlands, in addition to their ecological importance, are expected to mitigate the impact of storm surge by acting as a natural protection against hurricane flooding. Quantifying such interactions helps to provide a sound scientific basis to support planning and decision making. Using storm surge flooding from various historical hurricanes, simulated using a coupled hydrodynamic wave model (ADCIRC-SWAN), we propose an integrated framework yielding a geospatial identification of the capacity of Chesapeake Bay wetlands to protect critical infrastructure. Spatial identification of Chesapeake Bay wetlands is derived from the National Wetlands Inventory (NWI), National Land Cover Database (NLCD), and the Coastal Change Analysis Program (C-CAP). Inventories of population and critical infrastructure are extracted from US Census block data and FEMA's HAZUS-Multi Hazard geodatabase. Geospatial and statistical analyses are carried out to develop a relationship between wetland land cover, hurricane flooding, population and infrastructure vulnerability. These analyses result in the identification and quantification of populations and infrastructure in flooded areas that lie within a reasonable buffer surrounding the identified wetlands. Our analysis thus produces a spatial perspective on the potential for wetlands to attenuate hurricane flood impacts in critical areas. Statistical analysis will support hypothesis testing to evaluate the benefits of wetlands from a flooding and storm-surge attenuation perspective. Results from geospatial analysis are used to identify where interactions with critical infrastructure are relevant in the Chesapeake Bay.

  3. Production and Field Planting of Vegetative Propagules for Restoration of Redhead Grass and Sago Pondweed in Chesapeake Bay

    Science.gov (United States)

    2009-08-01

    1997). Most SAV species reproduce both sexually (flower, pollen , fruit, and seed) and asexually (clonally) for population expansion and long-term...perfoliatus produce abundant seeds (e.g., Yeo 1966; Ailstock and Shafer 2004), seed viability and germination success tend to be relatively low under most...technical note describes techniques for restoring P. perfoliatus and S. pecti- nata in the mesohaline region of Chesapeake Bay through the use of over

  4. Wave and Hydrodynamic Modeling for Engineering Design of Jetties at Tangier Island in Chesapeake Bay, USA

    Directory of Open Access Journals (Sweden)

    Lihwa Lin

    2015-12-01

    Full Text Available The protection of a boat canal at the western entrance of Tangier Island, Virginia, located in the lower Chesapeake Bay, is investigated using different structural alternatives. The existing entrance channel is oriented 45 deg with respect to the local shoreline, and exposed directly to the lower Bay without any protection. The adjacent shoreline has experienced progressive erosion in recent decades by flooding due to severe storms and waves. To protect the western entrance of the channel and shoreline, five different jetty and spur combinations were proposed to reduce wave energy in the lee of jetties. Environmental forces affecting the proposed jettied inlet system are quantified using the Coastal Modeling System, consisting of a spectral wave model and a depth-averaged circulation model with sediment transport calculations. Numerical simulations were conducted for design wave conditions and a 50-year return period tropical storm at the project site. Model results show a low crested jetty of 170-m length connecting to the north shore at a 45-deg angle, and a short south spur of 25-m long, provide adequate wave-reduction benefits among the five proposed alternatives. The model simulation indicates this alternative has the minimum impact on sedimentation around the structured inlet and boat canal.

  5. Climate-related relative sea-level changes from Chesapeake Bay, U.S. Atlantic coast

    Science.gov (United States)

    Shaw, Timothy; Horton, Benjamin; Kemp, Andrew; Cahill, Niamh; Mann, Michael; Engelhart, Simon; Kopp, Robert; Brain, Matthew; Clear, Jennifer; Corbett, Reide; Nikitina, Daria; Garcia-Artola, Ane; Walker, Jennifer

    2017-04-01

    Proxy-based reconstructions of relative sea level (RSL) from the coastlines of the North Atlantic have revealed spatial and temporal variability in the rates of RSL rise during periods of known Late-Holocene climatic variability. Regional driving mechanisms for such variability include glacial isostatic adjustment, static-equilibrium of land-ice changes and/or ocean dynamic effects as well as more localized factors (e.g. sediment compaction and tidal range change). We present a 4000-year RSL reconstruction from salt-marsh sediments of the Chesapeake Bay using a foraminiferal-based transfer function and a composite chronology. A local contemporary training set of foraminifera was developed to calibrate fossil counterparts and provide estimates of paleo marsh elevation with vertical uncertainties of ±0.06m. A composite chronology combining 30 radiocarbon dates, pollen chronohorizons, regional pollution histories, and short-lived radionuclides was placed into a Bayesian age-depth framework yielding low temporal uncertainties averaging 40 years. A compression-only geotechnical model was applied to decompact the RSL record. We coupled the proxy reconstruction with direct observations from nearby tide gauge records before rates of RSL rise were quantified through application of an Errors-In-Variables Integrated Gaussian Process model. The RSL history for Chesapeake Bay shows 6 m of rise since 2000 BCE. Between 2000 BCE and 1300 BCE, rates of RSL increasing to 1.4 mm/yr precede a significant decrease to 0.8 mm/yr at 700 BCE. This minimum coincides with widespread climate cooling identified in multiple paleoclimate archives of the North Atlantic. An increase in the rate of RSL rise to 2.1 mm/yr at 200 CE similarly precedes a decrease in the rate of RSL rise at 1450 CE (1.3 mm/yr) that coincides with the Little Ice Age. Modern rates of RSL rise (3.6 mm/yr) are the fastest observed in the past 4000 years. The temporal length and decadal resolution of the RSL reconstruction

  6. Estimation of regional hydrogeological properties for use in a hydrologic model of the Chesapeake Bay watershed

    Science.gov (United States)

    Seck, A.; Welty, C.

    2012-12-01

    Characterization of subsurface hydrogeologic properties in three dimensions and at large scales for use in groundwater flow models can remain a challenge owing to the lack of regional data sets and scatter in coverage, type, and format of existing small-scale data sets. This is the case for the Chesapeake Bay watershed, where numerous studies have been carried out to quantify groundwater processes at small scales but limited information is available on subsurface characteristics and groundwater fluxes at regional scales. One goal of this work is to synthesize disparate information on subsurface properties for the Chesapeake Bay watershed for use in a 3D integrated ParFlow model over an area of 400,000 km2 with a horizontal resolution of 1 km and a vertical resolution of 5 m. We combined different types of data at various scales to characterize hydrostratigraphy and hydrogeological properties. The conceptual hydrogeologic model of the study area is composed of two major regions. One region extends from the Valley and Ridge physiographic province south of New York to the Piedmont physiographic province in Maryland and Virginia. This region is generally characterized by fractured rock overlain by a mantle of regolith. Soil thickness and hydraulic conductivity values were obtained from the U.S. General Soil Map (STATSGO2). Saprolite thickness was evaluated using casing depth information from well completion reports from four state agencies. Geostatistical methods were used to generalize point data to the model extent and resolution. A three-dimensional hydraulic conductivity field for fractured bedrock was estimated using a published national map of permeability and depth- varying functions from literature. The Coastal Plain of Maryland, Virginia, Delaware and New Jersey constitutes the second region and is characterized by layered sediments. In this region, the geometry of 20 aquifers and confining units was constructed using interpolation of published contour maps of

  7. Cytochrome P450 and organochlorine contaminants in black-crowned night-herons from the Chesapeake Bay region, USA

    Science.gov (United States)

    Rattner, B.A.; Melancon, M.J.; Rice, C.P.; Riley, W.; Eisemann, J.; Hines, R.K.

    1997-01-01

    Black-crowned night-heron (Nycticorax nycticorax) offspring were collected from a relatively uncontaminated coastal reference site (next to Chincoteague National Wildlife Refuge, VA, USA) and two sites in the Chesapeake Bay watershed (Baltimore Harbor, MD and Rock Creek Park, Washington, DC, USA). Hepatic microsomal activities of benzyloxyresorufin-O-dealkylase and ethoxyresorufin-O-dealkylase were significantly elevated (up to sixfold and ninefold induction, respectively) in pipping embryos from the Baltimore Harbor colony compared to the reference site, whereas values in embryos from the Rock Creek Park colony were intermediate. Concentrations of organochlorine pesticides and metabolites in pipping embryos from both sites in the Chesapeake watershed were greater than at the reference site but below the known threshold for reproductive impairment. However, concentrations of 10 arylhydrocarbon receptor-active polychlorinated biphenyl (PCB) congeners and estimated toxic equivalents were up to 37-fold greater in embryos collected from these two sites in the Chesapeake Bay region, with values for toxic congeners 77 and 126 exceeding those observed in pipping heron embryos from the Great Lakes. Monooxygenase activity of pipping embryos was associated with concentrations of several organochlorine pesticides, total PCBs, arylhydrocarbon receptor-active PCB congeners, and toxic equivalents (r = 0.30-0.59), providing further evidence of the value of cytochrome P450 as a biomarker of organic contaminant exposure. Organochlorine contaminant levels were greater in 10-d-old nestlings from Baltimore Harbor than the reference site but had no apparent effect on monooxygenase activity or growth. These findings demonstrate induction of cytochrome P450 in pipping black-crowned night-heron embryos in the Chesapeake Bay region, probably by exposure to PCB congeners of local origin, and the accumulation of organochlorine pesticides and metabolites in nestling herons from Baltimore

  8. Monoclinic tridymite in clast-rich impact melt rock from the Chesapeake Bay impact structure

    Science.gov (United States)

    Jackson, J.C.; Horton, J.W.; Chou, I.-Ming; Belkin, H.E.

    2011-01-01

    X-ray diffraction and Raman spectroscopy confirm a rare terrestrial occurrence of monoclinic tridymite in clast-rich impact melt rock from the Eyreville B drill core in the Chesapeake Bay impact structure. The monoclinic tridymite occurs with quartz paramorphs after tridymite and K-feldspar in a microcrystalline groundmass of devitrified glass and Fe-rich smectite. Electron-microprobe analyses revealed that the tridymite and quartz paramorphs after tridymite contain different amounts of chemical impurities. Inspection by SEM showed that the tridymite crystal surfaces are smooth, whereas the quartz paramorphs contain irregular tabular voids. These voids may represent microporosity formed by volume decrease in the presence of fluid during transformation from tridymite to quartz, or skeletal growth in the original tridymite. Cristobalite locally rims spherulites within the same drill core interval. The occurrences of tridymite and cristobalite appear to be restricted to the thickest clast-rich impact melt body in the core at 1402.02-1407.49 m depth. Their formation and preservation in an alkali-rich, high-silica melt rock suggest initially high temperatures followed by rapid cooling.

  9. Derelict fishing gear in Chesapeake Bay, Virginia: spatial patterns and implications for marine fauna.

    Science.gov (United States)

    Bilkovic, Donna Marie; Havens, Kirk; Stanhope, David; Angstadt, Kory

    2014-03-15

    Derelict fishing gear is a source of mortality for target and non-target marine species. A program employing commercial watermen to remove marine debris provided a novel opportunity to collect extensive spatially-explicit information for four consecutive winters (2008-2012) on the type, distribution, and abundance of derelict fishing gear and bycatch in Virginia waters of Chesapeake Bay. The most abundant form of derelict gear recovered was blue crab pots with almost 32,000 recovered. Derelict pots were widely distributed, but with notable hotspot areas, capturing 40 species and over 31,000 marine organisms. The target species, blue crab, experienced the highest mortality from lost pots with an estimated 900,000 animals killed each year, a potential annual economic loss to the fishery of $300,000. Important fishery species were captured and killed in derelict pots including Atlantic croaker and black sea bass. While some causes of gear loss are unavoidable, others can be managed to minimize loss.

  10. Experimental alteration of artificial and natural impact melt rock from the Chesapeake Bay impact structure

    Science.gov (United States)

    Declercq, J.; Dypvik, H.; Aagaard, P.; Jahren, J.; Ferrell, R.E.; Horton, J. Wright

    2009-01-01

    The alteration or transformation of impact melt rock to clay minerals, particularly smectite, has been recognized in several impact structures (e.g., Ries, Chicxulub, Mj??lnir). We studied the experimental alteration of two natural impact melt rocks from suevite clasts that were recovered from drill cores into the Chesapeake Bay impact structure and two synthetic glasses. These experiments were conducted at hydrothermal temperature (265 ??C) in order to reproduce conditions found in meltbearing deposits in the first thousand years after deposition. The experimental results were compared to geochemical modeling (PHREEQC) of the same alteration and to original mineral assemblages in the natural melt rock samples. In the alteration experiments, clay minerals formed on the surfaces of the melt particles and as fine-grained suspended material. Authigenic expanding clay minerals (saponite and Ca-smectite) and vermiculite/chlorite (clinochlore) were identified in addition to analcime. Ferripyrophyllite was formed in three of four experiments. Comparable minerals were predicted in the PHREEQC modeling. A comparison between the phases formed in our experiments and those in the cores suggests that the natural alteration occurred under hydrothermal conditions similar to those reproduced in the experiment. ?? 2009 The Geological Society of America.

  11. Proposed tethered unmanned aerial system for the detection of pollution entering the Chesapeake Bay area

    Science.gov (United States)

    Goodman, J.; McKay, J.; Evans, W.; Gadsden, S. Andrew

    2016-05-01

    This paper is based on a proposed unmanned aerial system platform that is to be outfitted with high-resolution sensors. The proposed system is to be tethered to a moveable ground station, which may be a research vessel or some form of ground vehicle (e.g., car, truck, or rover). The sensors include, at a minimum: camera, infrared sensor, thermal, normalized difference vegetation index (NDVI) camera, global positioning system (GPS), and a light-based radar (LIDAR). The purpose of this paper is to provide an overview of existing methods for pollution detection of failing septic systems, and to introduce the proposed system. Future work will look at the high-resolution data from the sensors and integrating the data through a process called information fusion. Typically, this process is done using the popular and well-published Kalman filter (or its nonlinear formulations, such as the extended Kalman filter). However, future work will look at using a new type of strategy based on variable structure estimation for the information fusion portion of the data processing. It is hypothesized that fusing data from the thermal and NDVI sensors will be more accurate and reliable for a multitude of applications, including the detection of pollution entering the Chesapeake Bay area.

  12. The Medieval Climate Anomaly and Little Ice Age in Chesapeake Bay and the North Atlantic Ocean

    Science.gov (United States)

    Cronin, T. M.; Hayo, K.; Thunell, R.C.; Dwyer, G.S.; Saenger, C.; Willard, D.A.

    2010-01-01

    A new 2400-year paleoclimate reconstruction from Chesapeake Bay (CB) (eastern US) was compared to other paleoclimate records in the North Atlantic region to evaluate climate variability during the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA). Using Mg/Ca ratios from ostracodes and oxygen isotopes from benthic foraminifera as proxies for temperature and precipitation-driven estuarine hydrography, results show that warmest temperatures in CB reached 16-17. ??C between 600 and 950. CE (Common Era), centuries before the classic European Medieval Warm Period (950-1100. CE) and peak warming in the Nordic Seas (1000-1400. CE). A series of centennial warm/cool cycles began about 1000. CE with temperature minima of ~. 8 to 9. ??C about 1150, 1350, and 1650-1800. CE, and intervening warm periods (14-15. ??C) centered at 1200, 1400, 1500 and 1600. CE. Precipitation variability in the eastern US included multiple dry intervals from 600 to 1200. CE, which contrasts with wet medieval conditions in the Caribbean. The eastern US experienced a wet LIA between 1650 and 1800. CE when the Caribbean was relatively dry. Comparison of the CB record with other records shows that the MCA and LIA were characterized by regionally asynchronous warming and complex spatial patterns of precipitation, possibly related to ocean-atmosphere processes. ?? 2010.

  13. Brominated diphenyl ethers in the sediments, porewater, and biota of the Chesapeake Bay, USA

    Energy Technology Data Exchange (ETDEWEB)

    Baker, K.; Klosterhaus, S.; Liebert, D.; Stapleton, H. [Maryland Univ., Solomons, MD (United States)

    2004-09-15

    Levels of brominated diphenyl ethers (BDEs) are rapidly increasing in the environment, and in a short time these chemicals have evolved from 'emerging contaminants' to globally-distributed organic pollutants. Recent research demonstrates BDEs are sufficiently stable to be transported long distances in the environment and to accumulate in higher trophic levels. Photolysis and metabolism appear to be dominant loss processes for the parent compounds, generating a variety of lower brominated diphenyl ethers, hydroxylated metabolites, and other products. BDEs are hydrophobic, and therefore their transport in aquatic systems is likely controlled by sorption to sediments and perhaps exchange across the air-water interface. To date, few studies have examined the geochemistry of BDEs in natural waters. In this paper, we review our recent measurements of BDEs in the Chesapeake Bay, a shallow, productive estuary in eastern North America. We focus on the distribution of BDE congeners sediment, porewater, and in faunal benthos along a contamination gradient downstream from a wastewater treatment plant and on the spatial distribution of BDEs in bottom-feeding and pelagic fish species.

  14. Microcystin in aquatic food webs of the Baltic and Chesapeake Bay regions

    Science.gov (United States)

    Bukaveckas, Paul A.; Lesutienė, Jūratė; Gasiūnaitė, Zita R.; Ložys, Linas; Olenina, Irina; Pilkaitytė, Renata; Pūtys, Žilvinas; Tassone, Spencer; Wood, Joseph

    2017-05-01

    We undertook a comparative study of the James River Estuary, a sub-estuary of Chesapeake Bay, and the Curonian Lagoon, a sub-estuary of the Baltic Sea, to better understand the factors that determine the presence and persistence of algal toxins in food webs. Over a 2-year period, we measured microcystin concentrations in water, sediment and biota (fish and shellfish) at both sites. Across both food webs we found highest levels of microcystin among consumers of suspended particulate matter, including planktivorous fishes and filter-feeding shellfish, and lower levels of toxin among piscivores, scavengers and benthic omnivores. Despite similar levels of microcystin in the water column at the two sites, we observed higher toxin levels in fish and sediments of the Curonian Lagoon. We attribute this difference to the legacy of prior toxic cyanobacteria blooms in the Curonian Lagoon and hydrologic factors that result in a predominance of autochthonously-derived organic matter in the sediments at this site. Our results suggest that a consideration of species-specific differences in feeding habits, and organic matter sources supporting food webs are important to understanding the accumulation and persistence of algal toxins in food webs and should therefore be considered in assessment of risks to aquatic biota and human health.

  15. Reproductive health of yellow perch Perca flavescens in selected tributaries of the Chesapeake Bay

    Science.gov (United States)

    Blazer, Vicki; Pinkney, Alfred E.; Jenkins, Jill A.; Iwanowicz, Luke R.; Minkkinen, Steven; Draugelis-Dale, Rassa O.; Uphoff, James H.

    2013-01-01

    Reduced recruitment of yellow perch has been noted for a number of years in certain urbanized watersheds (South and Severn Rivers) of the Chesapeake Bay. Other rapidly developing watersheds such as Mattawoman Creek are more recently showing evidence of reduced recruitment of anadromous fishes. In this study, we used a battery of biomarkers to better document the reproductive health of adult yellow perch collected during spring spawning in 2007–2009. Perch were collected in the South and Severn Rivers, Mattawoman Creek and the less developed Choptank and Allen's Fresh watersheds for comparison. Gonadosomatic indices, plasma reproductive hormone concentrations, plasma vitellogenin concentrations and gonad histology were evaluated in mature perch of both sexes. In addition, sperm quantity (cell counts) and quality (total and progressive motility, spermatogenic stage and DNA integrity), were measured in male perch. Many of these biomarkers varied annually and spatially, with some interesting statistical results and trends. Male perch from the Choptank and Allen's Fresh had generally higher sperm counts. In 2008 counts were significantly lower in the perch from the Severn when compared to other sites. The major microscopic gonadal abnormality in males was the proliferation of putative Leydig cells, observed in testes from Severn and less commonly, Mattawoman Creek perch. Observations that could significantly impact egg viability were an apparent lack of final maturation, abnormal yolk and thin, irregular zona pellucida. These were observed primarily in ovaries from Severn, South and less commonly Mattawoman Creek perch. The potential association of these observations with urbanization, impervious surface and chemical contaminants is discussed.

  16. Remineralization VS Reductive Dissolution Pathway of Phosphorus Cycling: a Case Study in the Chesapeake Bay

    Science.gov (United States)

    Jaisi, D. P.; Joshi, S.; Kukkadapu, R. K.; Burdige, D.; Sparks, D. L.

    2015-12-01

    Coastal hypoxia have spread exponentially worldwide due to increased anthropogenic loading of nutrients in coastal waters. Hypoxia exerts an influence on the stability of minerals and organic debris, direction of nutrient flux at the sediment-water interface, and the extent of benthic-pelagic coupling. This study aimed to address fundamental questions related to sediment phosphorus (P) dynamics in response to transient bottom water hypoxia particularly on P effluxes at the sediment-water interface and P burial (as authigenic/vivianite P) under two pathways: remineralization of organic P (coupled C-P pathway) and reductive dissolution of ferric Fe-bound P (coupled Fe-P pathway). Authigenic phosphate isotope data suggest that the regeneration of inorganic P in the sediment from organic matter degradation (remineralization) is the predominant, if not sole, pathway for authigenic P precipitation in the sediments. Interestingly, ferric Fe-bound phosphate oxygen isotopes are heavier than equilibrium. This means that the ferric Fe-bound P pool in these sediments is largely composed of particulate P from terrestrial sources composed primarily of Fe phyllosilicates plus potentially vivianite that are largely resistant against dissolution in the anoxic sediment column. These results collectively support the predominance of coupled C-P pathway of P cycling, rather than Fe-P coupling, in hypoxic environment in the Chesapeake Bay.

  17. Interaction of Students and Scientists in the Chesapeake Bay Watershed Education and Training and Emerging Scientist Programs

    Science.gov (United States)

    Bieri, J.; Sprague, S.; Bloch, N.; Laubhan, S.

    2006-05-01

    NOAA's Chesapeake Bay Office (NCBO) is actively engaged in K-12 science education within the Chesapeake Bay watershed. Through the Bay Watershed Education and Training Program (B-WET) and the Emerging Scientist Project, we are furthering the Chesapeake Bay Program (CBP) goal of providing a meaningful watershed experience for every student prior to their graduation from high school. These projects seek to provide field experiences for students coupled with both pre-experience and post-experience integration in the classroom. In many cases, NCBO funded projects partner school educators with the scientific community. Partnering scientists assist teachers with resources in the field, classroom and on-line. In many cases, students are actively engaged in data collection (fish or invertebrate species data, water quality parameters, other physical site specific data) that can be incorporated into the partnering scientists existing data bases. Scientists are able to increase their database while at the same time provide teachers and students with a meaningful field experience that exposes students to authentic research and field sampling. This type of field experience lends itself nicely to applicable follow-up activites and analysis back in the classroom. Students may take this "real data" and use for discussion of application of management decisions and/or actually implement changes within their community (i.e. restoration projects). This presentation will highlight several B- WET projects as well as the ESP that have succeeded in engaging a K-12 audience in authentic science. Scientific partners include the Smithsonian Environmental Research Consortium (SERC), the University of Maryland (UMD) and the Virginia Institute of Marine Science (VIMS).

  18. Concentrations of metals in blood and feathers of nestling ospreys (Pandion haliaetus) in Chesapeake and Delaware Bays

    Science.gov (United States)

    Rattner, B.A.; Golden, N.H.; Toschik, P.C.; McGowan, P.C.; Custer, T.W.

    2008-01-01

    In 2000, 2001, and 2002, blood and feather samples were collected from 40-45-day-old nestling ospreys (Pandion haliaetus) from Chesapeake Bay and Delaware Bay and River. Concentrations of 18 metals, metalloids, and other elements were determined in these samples by inductively coupled plasma-mass spectroscopy, and Hg concentrations were measured by cold vapor atomic absorption spectroscopy. When compared to concurrent reference areas (South, West, and Rhode Rivers), mean As and Hg concentrations in blood were greater (p mean Al, Ba, Hg, Mn, and Pb concentrations in feathers were substantially greater (p < 0.05) in one or more Chesapeake regions of concern (Anacostia River [Al: 206 vs. 62.1 mug/g dw; Ba: 3.31 vs. 0.823 mug/g dw; Mn: 65.4 vs. 22.9 mug/g dw] and Elizabeth River [Al: 165 vs. 63.5 mug/g dw; Hg: 1.24 vs. 0.599 mug/g dw; Pb 1.47 vs. 0.543 mug/g dw]). When compared to the coastal Inland Bays reference area, feathers of nestlings from northern Delaware Bay and River had greater concentrations (p < 0.05) of Ba (1.90 vs. 0.660 mug/g dw), Fe (258 vs. 109 mug/g dw), Mn (18.5 vs. 4.66 mug/g dw), Mo (0.130 vs. 0.040 mug/g dw), Pb (1.96 vs. 0.624 mug/g dw), and V (0.671 vs. 0.325 mug/g dw), presumably due to extensive metal-working and petroleum refinery activities. Concentrations of Hg in nestling feathers from Delaware were frequently greater than in the Chesapeake. The present findings and those of related reproductive studies suggest that concentrations of several heavy metals (e.g., Cd, Hg, Pb) in nestling blood and feathers from Chesapeake and Delaware Bays were below toxicity thresholds and do not seem to be affecting chick survival during the nestling period.

  19. Chronicling long-term predator responses to a shifting forage base in Chesapeake Bay: an energetics approach

    Science.gov (United States)

    Overton, Anthony S.; Griffin, Jennifer C.; Margraf, F. Joseph; May, Eric B.; Hartman, Kyle J.

    2015-01-01

    The population of Striped Bass Morone saxatilis in Chesapeake Bay has increased significantly since the 1980s because of management efforts while the relative abundance of some key prey fish has declined since the 1970s. We examined the trophic interactions and prey consumption patterns of Striped Bass in Chesapeake Bay to determine how Striped Bass have responded to changing prey resources. Seasonal diet, growth, and thermal data were collected from 1955 to 1959, 1990 to 1992, and 1998 to 2001; these data were coupled with a bioenergetics model approach to characterize temporal patterns in prey consumption for Striped Bass. The estimates were compared across each period to build a historical prey consumption profile from 1955 to 2001. Prey consumption dynamics for Striped Bass have changed dramatically between 1955 and 2001. In general, Striped Bass in the early and late 1990s consumed less Atlantic Menhaden Brevoortia tyranus and more Bay Anchovy Anchoa mitchilli than during the 1950s. The largest differences in consumption were observed in the younger age-classes. During 1998–2001, age-1 and age-2 Striped Bass consumed, respectively, 15.5 and 11.9 times less Atlantic Menhaden than during the 1950sand 12.2 and 7.2 less than during 1990–1992. Bay Anchovy were almost absent in the diet of bass age 3 and older during the 1950s but were consumed by the age-3+ group during 1990–1992 and to a greater extent during 1998–2001. Age-3+ Striped Bass during 1998–2001, on average, consumed twice as much Bay Anchovy than during 1990–1992. Blue crab Callinectes sappidus were consumed only by age 2 in the 1950s and 1990–1992 and by ages 2 and older in 1998–2001. Age-2 bass consumed 8.8 more blue crab in 1990–1992 and 7.5 times more in 1998–2001 than during the 1950s. The patterns in the consumption of Atlantic Menhaden coincided with increased consumption of Bay Anchovy and blue crab, possibly as a result of the declines in Atlantic Menhaden

  20. A 3D, cross-scale, baroclinic model with implicit vertical transport for the Upper Chesapeake Bay and its tributaries

    Science.gov (United States)

    Ye, Fei; Zhang, Yinglong J.; Friedrichs, Marjorie A. M.; Wang, Harry V.; Irby, Isaac D.; Shen, Jian; Wang, Zhengui

    2016-11-01

    We develop a new vertically implicit transport solver, based on two total variation diminishing (TVD) limiters in space and time, inside a 3D unstructured-grid model (SCHISM), and apply it to the Upper Chesapeake Bay (UCB), which has complex geometry and sharp pycnocline. We show that the model is able to accurately and efficiently capture the elevation, velocity, salinity and temperature in both the deep and shallow regions of UCB. Compared with all available CTD casts, the overall model skills have the mean absolute error of 1.08 PSU and 0.85 °C, and correlation coefficient of 0.97 and 0.99 for salinity and temperature respectively. More importantly, the new implicit solver better captures the density stratification, which has great implications on biogeochemistry in this estuarine system. The cross-scale capability of the model is demonstrated by extending the high-resolution grids into a tributary (Chester River) and its sub-tributary (Corsica River), with minimal impact on the model efficiency. The model is also able to capture complex 3D structures at the transition zone between the main bay and the tributary, including the three-layered circulation in Baltimore Harbor. As more and more attention is being paid to the productive shallows in the Chesapeake Bay and other estuaries, the model can serve as a very powerful management tool to understand the impact of both local and remote forcing functions.

  1. An Approach to Understanding Complex Socio-Economic Impacts and Responses to Climate Disruption in the Chesapeake Bay Region

    Science.gov (United States)

    Schaefer, R. K.; Nix, M.; Ihde, A. G.; Paxton, L. J.; Weiss, M.; Simpkins, S.; Fountain, G. H.; APl GAIA Team

    2011-12-01

    In this paper we describe the application of a proven methodology for modeling the complex social and economic interactions of a system under stress to the regional issues that are tied to global climate disruption. Under the auspices of the GAIA project (http://gaia.jhuapl.edu), we have investigated simulating the complex interplay between climate, politics, society, industry, and the environment in the Chesapeake Bay Watershed and associated geographic areas of Maryland, Virginia, and Pennsylvania. This Chesapeake Bay simulation draws on interrelated geophysical and climate models to support decision-making analysis about the Bay. In addition to physical models, however, human activity is also incorporated via input and output calculations. For example, policy implications are modeled in relation to business activities surrounding fishing, farming, industry and manufacturing, land development, and tourism. This approach fosters collaboration among subject matter experts to advance a more complete understanding of the regional impacts of climate change. Simulated interactive competition, in which teams of experts are assigned conflicting objectives in a controlled environment, allow for subject exploration which avoids trivial solutions that neglect the possible responses of affected parties. Results include improved planning, the anticipation of areas of conflict or high risk, and the increased likelihood of developing mutually acceptable solutions.

  2. Species-specific accumulation of polybrominated diphenyl ether flame retardants in birds of prey from the Chesapeake Bay region, USA

    Energy Technology Data Exchange (ETDEWEB)

    Chen Da, E-mail: chen@vims.ed [Department of Environmental and Aquatic Animal Health, Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, VA 23062 (United States); Hale, Robert C. [Department of Environmental and Aquatic Animal Health, Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, VA 23062 (United States); Watts, Bryan D. [Center for Conservation Biology, College of William and Mary, Williamsburg, VA 23185 (United States); La Guardia, Mark J.; Harvey, Ellen [Department of Environmental and Aquatic Animal Health, Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, VA 23062 (United States); Mojica, Elizabeth K. [Center for Conservation Biology, College of William and Mary, Williamsburg, VA 23185 (United States)

    2010-05-15

    Compared to organochlorines, little is known about polybrominated diphenyl ether (PBDE) contamination of birds of prey breeding in the Chesapeake Bay, the largest estuary in the U.S. This study examined and compared PBDE contamination in eggs of osprey, double-crested cormorant, brown pelican and peregrine falcon from this area. Several legacy persistent organic pollutants such as PCBs and DDE were also investigated. The level of urbanization of the landscape appeared to influence the level of PBDE exposure. PBDE congener distribution patterns varied between piscivorous and terrestrial-feeding birds. This suggests individual congeners may be subject to differences in bioaccumulation, biomagnification or metabolism in the aquatic and terrestrial food webs. Biomagnification of PBDEs was studied in the Bay aquatic food chains for the first time. A biomagnification factor of 25.1 was estimated for SIGMAPBDEs for the fish - osprey egg food chain. Hazard quotients, applied as a preliminary evaluation, indicated that PBDEs may pose a moderate hazard to ospreys and peregrine falcons through impairment of reproductive performance. - Birds of prey breeding in the Chesapeake Bay (USA) exhibited species-specific PBDE accumulation patterns.

  3. Osmium-Isotope and Platinum-Group-Element Systematics of Impact-Melt Rocks, Chesapeake Bay Impact Structure, Virginia, USA

    Science.gov (United States)

    Lee, Seung Ryeol; Wright Horton, J., Jr.; Walker, Richard J.

    2005-01-01

    Osmium (Os) isotopes and platinum-group elements (PGEs) are useful for geochemically identifying a meteoritic component within impact structures, because meteorites are typically characterized by low (187)Os/(188)Os ratios and high PGE concentrations. In contrast, most types of crustal target rocks have high radiogenic Os and very low PGE concentrations. We have examined Os isotope and PGE systematics of impact-melt rocks and pre-impact target rocks from a 2004 test hole in the late Eocene Chesapeake Bay impact structure and from nearby coreholes. Our goal is to determine the proportion of the projectile component in the melt rock Additional information is included in the original extended abstract.

  4. Vertical distribution of first stage larvae of the blue crab, Callinectes sapidus, at the mouth of Chesapeake Bay

    Science.gov (United States)

    Provenzano, Anthony J.; McConaugha, John R.; Philips, Kathleen B.; Johnson, David F.; Clark, John

    1983-05-01

    The vertical distribution of stage I blue crab larvae, near the mouth of Chesapeake Bay, was examined over four diurnal cycles. Each of two stations was occupied for 30 hours twice during the summer of 1979. On each of the four cruises, peak larval abundance occurred after a night time high slack tide, suggesting a synchronized hatch of blue crab larvae. 90-99% of all larvae collected were taken in the neuston layer. The apparent timing of the hatches to coincide with the beginning of an ebb tide and the concentration of larvae in the neuston layer strongly suggests seaward transport of these early stage larvae and the probability of offshore development.

  5. Origin and emplacement of impactites in the Chesapeake Bay impact structure, Virginia, USA

    Science.gov (United States)

    Horton, J.W.; Gohn, G.S.; Powars, D.S.; Edwards, L.E.

    2007-01-01

    The late Eocene Chesapeake Bay impact structure, located on the Atlantic margin of Virginia, may be Earth's best-preserved large impact structure formed in a shallow marine, siliciclastic, continental-shelf environment. It has the form of an inverted sombrero in which a central crater ???40 km in diameter is surrounded by a shallower brim, the annular trough, that extends the diameter to ???85 km. The annular trough is interpreted to have formed largely by the collapse and mobilization of weak sediments. Crystalline-clast suevite, found only in the central crater, contains clasts and blocks of shocked gneiss that likely were derived from the fragmentation of the central-uplift basement. The suevite and entrained megablocks are interpreted to have formed from impact-melt particles and crystalline-rock debris that never left the central crater, rather than as a fallback deposit. Impact-modified sediments in the annular trough include megablocks of Cretaceous nonmarine sediment disrupted by faults, fluidized sands, fractured clays, and mixed-sediment intercalations. These impact-modified sediments could have formed by a combination of processes, including ejection into and mixing of sediments in the water column, rarefaction-induced fragmentation and clastic injection, liquefaction and fluidization of sand in response to acoustic-wave vibrations, gravitational collapse, and inward lateral spreading. The Exmore beds, which blanket the entire crater and nearby areas, consist of a lower diamicton member overlain by an upper stratified member. They are interpreted as unstratified ocean-resurge deposits, having depositional cycles that may represent stages of inward resurge or outward anti-resurge flow, overlain by stratified fallout of suspended sediment from the water column. ?? 2008 The Geological Society of America. All rights reserved.

  6. Chesapeake Bay impact structure: Morphology, crater fill, and relevance for impact structures on Mars

    Science.gov (United States)

    Horton, J.W.; Ormo, J.; Powars, D.S.; Gohn, G.S.

    2006-01-01

    The late Eocene Chesapeake Bay impact structure (CBIS) on the Atlantic margin of Virginia is one of the largest and best-preserved "wet-target" craters on Earth. It provides an accessible analog for studying impact processes in layered and wet targets on volatile-rich planets. The CBIS formed in a layered target of water, weak clastic sediments, and hard crystalline rock. The buried structure consists of a deep, filled central crater, 38 km in width, surrounded by a shallower brim known as the annular trough. The annular trough formed partly by collapse of weak sediments, which expanded the structure to ???85 km in diameter. Such extensive collapse, in addition to excavation processes, can explain the "inverted sombrero" morphology observed at some craters in layered targets. The distribution of crater-fill materials i n the CBIS is related to the morphology. Suevitic breccia, including pre-resurge fallback deposits, is found in the central crater. Impact-modified sediments, formed by fluidization and collapse of water-saturated sand and silt-clay, occur in the annular trough. Allogenic sediment-clast breccia, interpreted as ocean-resurge deposits, overlies the other impactites and covers the entire crater beneath a blanket of postimpact sediments. The formation of chaotic terrains on Mars is attributed to collapse due to the release of volatiles from thick layered deposits. Some flat-floored rimless depressions with chaotic infill in these terrains are impact craters that expanded by collapse farther than expected for similar-sized complex craters in solid targets. Studies of crater materials in the CBIS provide insights into processes of crater expansion on Mars and their links to volatiles. ?? The Meteoritical Society, 2006.

  7. Restoration of waterbird habitats in Chesapeake Bay: Great expectations or Sisyphus revisited?

    Science.gov (United States)

    Erwin, R.M.; Beck, R.A.; Erwin, R. Michael; Watts, Bryan D.; Haramis, G.Michael; Perry, Matthew C.; Hobson, Keith A.

    2007-01-01

    In the past half century, many waterbird populations in Chesapeake Bay have declined or shifted ranges, indicating major ecological changes have occurred. While many studies have focused on the problems associated with environmental degradation such as the losses of coastal wetlands and submerged vegetation, a number of restoration efforts have been launched in the past few decades to reverse the 'sea of despair.' Most pertinent to waterbirds, restoration of submerged aquatic vegetation (SAV) beds, tidal wetland restoration, oyster reef restoration, and island creation/restoration have benefited a number of species. State and federal agencies and non government agencies have formed partnerships to spawn many projects ranging in size from less than 0.5 ha to ca. 1,000 ha. While most SAV, wetland, and oyster reef projects have struggled to different degrees over the past ten to twenty years with inconsistent methods, irregular monitoring, and unknown reasons for failures, recent improvements in techniques and application of adaptive management have been made. The large dredge-material island at Hart-Miller Island near Baltimore, Poplar Island west of Tilghman Island, Maryland, and Craney Island Portsmouth, Virginia have provided large outdoor 'laboratories' for wildlife, fishery, and wetland habitat creation. All three have proven to be important for nesting waterbirds and migrant shorebirds and waterfowl; however nesting populations at all three islands have been compromised to different degrees by predators. Restoration success for waterbirds and other natural resources depends on: (1) establishing realistic, quantifiable objectives and performance criteria, (2) continued monitoring and management (e.g., predator control), (3) targeted research to determine causality, and (4) careful evaluation under an adaptive management regime.

  8. Relation of lead exposure to sediment ingestion in mute swans on the Chesapeake Bay, USA

    Science.gov (United States)

    Beyer, W.N.; Day, D.; Morton, Alexandra; Pachepsky, Y.

    1998-01-01

    Forty-two mute swans (Cygnus olor ) were collected from unpolluted portions of central Chesapeake Bay in spring 1995. Their intestinal digesta were analyzed for 13 metals (Al, B, Ba, Cd, Cu, Fe, Mg, Mn, Ni, Pb, Sr, V, Zn) and for acid-insoluble ash, a marker of sediment. Because metal concentrations in digesta depend on recent exposure, they are appropriate for evaluating local contamination. Swan livers and sediment samples also were analyzed for the same metals. Group method of data handling demonstrated that the digesta Al was the best predictor of digesta Pb, and that adding concentrations of other metals as predictors did not improve the accuracy of the estimates of Pb concentrations from Al concentrations. The r2 of the equation relating the log of digesta Pb to the log of digesta Al was 0.86, whereas the r2 of the equation relating the log of digesta Pb to the log of digesta acid-insoluble ash was 0.50. Sediment ingestion was critical in determining exposure to Pb, as well as to some of the other metals, and should be considered in ecotoxicological risk assessments of waterfowl. The mean of 7.4% acid-insoluble ash in the digesta corresponded to an estimated 3.2% sediment in the diet. The Pb concentrations in the digesta were 2-3 times the concentration that would have been predicted from sediment Pb concentrations; presumably the swans had ingested clays high in Pb that had settled on the vegetation. The swans were not thought to have been exposed to high Cu concentrations but they had hepatic Cu concentrations that would be considered very high if found in other species.

  9. Optimal hydrograph separation using a recursive digital filter constrained by chemical mass balance, with application to selected Chesapeake Bay watersheds

    Science.gov (United States)

    Raffensperger, Jeff P.; Baker, Anna C.; Blomquist, Joel D.; Hopple, Jessica A.

    2017-06-26

    Quantitative estimates of base flow are necessary to address questions concerning the vulnerability and response of the Nation’s water supply to natural and human-induced change in environmental conditions. An objective of the U.S. Geological Survey National Water-Quality Assessment Project is to determine how hydrologic systems are affected by watershed characteristics, including land use, land cover, water use, climate, and natural characteristics (geology, soil type, and topography). An important component of any hydrologic system is base flow, generally described as the part of streamflow that is sustained between precipitation events, fed to stream channels by delayed (usually subsurface) pathways, and more specifically as the volumetric discharge of water, estimated at a measurement site or gage at the watershed scale, which represents groundwater that discharges directly or indirectly to stream reaches and is then routed to the measurement point.Hydrograph separation using a recursive digital filter was applied to 225 sites in the Chesapeake Bay watershed. The recursive digital filter was chosen for the following reasons: it is based in part on the assumption that groundwater acts as a linear reservoir, and so has a physical basis; it has only two adjustable parameters (alpha, obtained directly from recession analysis, and beta, the maximum value of the base-flow index that can be modeled by the filter), which can be determined objectively and with the same physical basis of groundwater reservoir linearity, or that can be optimized by applying a chemical-mass-balance constraint. Base-flow estimates from the recursive digital filter were compared with those from five other hydrograph-separation methods with respect to two metrics: the long-term average fraction of streamflow that is base flow, or base-flow index, and the fraction of days where streamflow is entirely base flow. There was generally good correlation between the methods, with some biased

  10. Bio-optics of the Chesapeake Bay from measurements and radiative transfer closure

    Science.gov (United States)

    Tzortziou, Maria; Herman, Jay R.; Gallegos, Charles L.; Neale, Patrick J.; Subramaniam, Ajit; Harding, Lawrence W., Jr.; Ahmad, Ziauddin

    2006-06-01

    We combined detailed bio-optical measurements and radiative transfer modeling to perform an 'optical closure' experiment for an optically complex and biologically productive region of the Chesapeake Bay. We used this experiment to evaluate certain assumptions commonly used in bio-optical models, and to investigate which optical characteristics are most important to accurately model and interpret remote sensing ocean-color observations in these Case 2 waters. Direct measurements were made of the magnitude, variability, and spectral characteristics of backscattering and absorption that are critical for accurate parameterizations in satellite bio-optical algorithms and underwater radiative transfer simulations. We found that the ratio of backscattering to total scattering (i.e. the backscattering fraction, bb/ b) varied considerably depending on particulate loading, distance from land, and mixing processes, and had an average value of 0.0128 at 530 nm. Incorporating information on the magnitude, variability, and spectral characteristics of particulate backscattering into the radiative transfer model, rather than using a volume scattering function commonly assumed for turbid waters, was critical to obtaining agreement between model calculations and measured radiometric quantities. In-situ measurements of absorption coefficients need to be corrected for systematic overestimation due to scattering errors, and this correction commonly employs the assumption that absorption by particulate matter at near-infrared wavelengths is zero. Direct measurements, however, showed that particulate matter in the Bay had small, but non-zero, absorption in the 700-730 nm wavelength region. Accounting for this residual particulate absorption when correcting in-situ measured absorption spectra for scattering errors was important in model simulations of water reflectance in the green wavelengths, where reflectance spectra in estuarine waters peak. Sun-induced chlorophyll fluorescence

  11. Diets and trophic-guild structure of a diverse fish assemblage in Chesapeake Bay, U.S.A.

    Science.gov (United States)

    Buchheister, A; Latour, R J

    2015-03-01

    Dietary habits and trophic-guild structure were examined in a fish assemblage (47 species) of the Chesapeake Bay estuary, U.S.A., using 10 years of data from >25 000 fish stomachs. The assemblage was comprised of 10 statistically significant trophic guilds that were principally differentiated by the relative amounts of Mysida, Bivalvia, Polychaeta, Teleostei and other Crustacea in the diets. These guilds were broadly aggregated into five trophic categories: piscivores, zooplanktivores, benthivores, crustacivores and miscellaneous consumers. Food web structure was largely dictated by gradients in habitat (benthic to pelagic) and prey size. Size classes within piscivorous species were more likely to be classified into different guilds, reflecting stronger dietary changes through ontogeny relative to benthivores and other guilds. Relative to predator species and predator size, the month of sampling had negligible effects on dietary differences within the assemblage. A majority of sampled fishes derived most of their nutrition from non-pelagic prey sources, suggesting a strong coupling of fish production to benthic and demersal food resources. Mysida (predominantly the opossum shrimp Neomysis americana) contributed substantially to the diets of over 25% of the sampled predator groups, indicating that this species is a critical, but underappreciated, node in the Chesapeake Bay food web.

  12. Long-term changes in sediment and nutrient delivery from Conowingo Dam to Chesapeake Bay: Effects of reservoir sedimentation

    Science.gov (United States)

    Zhang, Qian; Hirsch, Robert M.; Ball, William P.

    2016-01-01

    Reduction of suspended sediment (SS), total phosphorus (TP), and total nitrogen is an important focus for Chesapeake Bay watershed management. The Susquehanna River, the bay’s largest tributary, has drawn attention because SS loads from behind Conowingo Dam (near the river’s mouth) have been rising dramatically. To better understand these changes, we evaluated histories of concentration and loading (1986–2013) using data from sites above and below Conowingo Reservoir. First, observed concentration-discharge relationships show that SS and TP concentrations at the reservoir inlet have declined under most discharges in recent decades, but without corresponding declines at the outlet, implying recently diminished reservoir trapping. Second, best estimates of mass balance suggest decreasing net deposition of SS and TP in recent decades over a wide range of discharges, with cumulative mass generally dominated by the 75∼99.5th percentile of daily Conowingo discharges. Finally, stationary models that better accommodate effects of riverflow variability also support the conclusion of diminished trapping of SS and TP under a range of discharges that includes those well below the literature-reported scour threshold. Overall, these findings suggest that decreased net deposition of SS and TP has occurred at subscour levels of discharge, which has significant implications for the Chesapeake Bay ecosystem.

  13. δ15N Values in Crassostrea virginica Shells Provides Early Direct Evidence for Nitrogen Loading to Chesapeake Bay

    Science.gov (United States)

    Black, H. D.; Andrus, C. F. T.; Lambert, W. J.; Rick, T. C.; Gillikin, D. P.

    2017-01-01

    Crassostrea virginica is one of the most common estuarine bivalves in the United States’ east coast and is frequently found in archaeological sites and sub-fossil deposits. Although there have been several sclerochronological studies on stable carbon and oxygen isotopes in the shells of this species, less is known about δ15N values within their shells, which could be a useful paleoenvironmental proxy to assess estuarine nitrogen dynamics. Modern C. virginica samples were collected in Chesapeake Bay for comparison with archaeological shells from nearby sites ranging in age from ~100 to 3,200 years old. Left valves were sampled by milling the hinge area and the resulting powder was analyzed for %N and δ15N values. Comparison of δ15N values between C. virginica shells shows relatively constant values from ~1250 BC to ~1800 AD. After ~1800 AD, there are rapid increases in 15N enrichment in the shells, which continue to increase in value up to the modern shell values. The increase in δ15N values is evidence of early anthropogenic impact in Chesapeake Bay. These results corroborate the observation that coastal nitrogen pollution occurred earlier than the 19th century and support the use of oyster shell δ15N values as a useful environmental proxy. PMID:28281649

  14. Recreating the 1950’s Chesapeake Bay: Use of a Network Model to Guide the Application of a Eutrophication Model

    Science.gov (United States)

    2009-08-01

    1950’s RMB1. This could have resulted from decreased phyto- hen compared to base results. In particular, SR2 to , een nd deep layers of the...19 Figure 4. Microphytobenthic algae limitation...In the shallow-water bottom of the Chesapeake Bay, microphytobenthos (microscopic, photosynthetic eukaryotic algae and cyanobacteria) were believed

  15. OYSTER POPULATUION ESTIMATION IN SUPPORT OF THE TEN-YEAR GOAL FOR OYSTER RESOTRATION IN THE CHESAPEAKE BAY: DEVELOPING STRATEGIES FOR RESTORING AND MANAGING THE EASTERN OYSTER

    Science.gov (United States)

    Mann, Roger, Steve Jordan, Gary Smith, Kennedy Paynter, James Wesson, Mary Christman, Jessica Vanisko, Juliana Harding, Kelly Greenhawk and Melissa Southworth. 2003. Oyster Population Estimation in Support of the Ten-Year Goal for Oyster Restoration in the Chesapeake Bay: Develop...

  16. Study of the possible role of pollution in the prevalence of sea nettles in the Chesapeake Bay and the development of a census taking method

    Science.gov (United States)

    1971-01-01

    A study of the effect of pollutants on the sea nettle population of Chesapeake Bay was conducted. The effects of pollutants on the polyp stage of the nettle were stressed. Methods of detecting adult sea nettles by remote sensing are discussed. The effects of phosphate, nitrate, ammonium, and combinations of these pollutants were investigated.

  17. Effects of energy related activities on the plankton of the Chesapeake Bay. Section I. Work in progress. Progress report, 1 August 1975--31 July 1976

    Energy Technology Data Exchange (ETDEWEB)

    Taft, J.L.

    1976-04-01

    Progress is reported on the following research projects: release of dissolved organic carbon by phytoplankton; plankton respiration and nutrient regeneration; bacterial utilization of labeled compounds; effects of heat and chlorine on natural assemblages of Chesapeake Bay phytoplankton; and nutrient flux between sediment and water. (HLW)

  18. Evaluation of Salinity-Related Habitat Impacts in the Lower Chesapeake Bay and James River for the Norfolk Harbor and Channels Deepening Study.

    Science.gov (United States)

    1984-10-01

    and by two protozoan parasites , Minchinia nelsoni ("MSX") and Perkinsus marinus ("dermo"). Salinity Relationships - Crassostrea virginica is an...affecting density and abundance of oysters in Chesapeake Bay are predation and disease (actually, protozoan parasites ). Minchinia nelsoni ("MSX") was

  19. NODC Standard Product: Coastal Change Analysis Program (C-CAP) Chesapeake Bay Region Data from 1984 to 1989 on CD-ROM (NODC Accession 9200303)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data set on this CD-ROM shows changes in land cover for the Chesapeake Bay region over the 5-year interval from 1984 to 1988-89. The data set was produced...

  20. Mesoscale geomorphic change on low energy barrier islands in Chesapeake Bay, U.S.A.

    Science.gov (United States)

    Cooper, J. Andrew G.

    2013-10-01

    This paper presents an analysis of decadal (mesoscale) geomorphic change on sandy barrier islands in the fetch-limited environment of Chesapeake Bay. Low energy barrier islands exist in two settings: on the fringe of marshes and in open water and this analysis shows the various types of barrier island to be genetically related. Barrier islands that face the dominant wind and wave direction (E or W) retreat via barrier translation, preserving the barrier island volume. Those that exist in re-entrants are dominated by longshore transport processes, are strongly affected by sediment supply and are subject to disintegration. Marsh fringe barrier islands are perched on or draped over the surface of the underlying marsh. They migrate landwards via barrier translation during periodic high water events accompanied by large waves (hurricanes and northeasters). The underlying marsh surface erodes under all water levels and the rate of retreat of the barrier island and underlying marsh may take place at different rates, leading to various configurations from perched barrier islands several metres landward of the marsh edge, to barrier islands that have a sandy shoreface extending into the subtidal zone. The coastal configuration during landward retreat of marsh fringe barrier islands is subject to strong local control exerted by the underyling marsh topography. As erosion of marsh promontories occurs and marsh creeks are intersected and bypassed, the configuration is subject to rapid change. Periodic sediment influxes cause spits to develop at re-entrants in the marsh. The spits are initiated as extensions of adjacent marsh fringe barrier islands, but as the sediment volume is finite, the initial drift-aligned spits become sediment-starved and begin to develop a series of swash-aligned cells as they strive for morphodynamic equilibrium. The individual cells are stretched until breaches form in the barrier islands, creating inlets with tidal deltas. At this stage the low

  1. Nutrient and Sediment Reductions from Algal Flow-Way Technologies: Recommendations to the Chesapeake Bay Program's Water Quality Goal Implementation Team from the Algal Flow-Way Technologies BMP Expert Panel

    Science.gov (United States)

    The Chesapeake Stormwater Network hosted a workshop on July, 2012 to discuss the potential nutrient reductions from emerging stormwater technologies including algal flow-way technologies (AFTs). Workshop participants recommended the Chesapeake Bay Program’s Water Quality Goal Implementation Team(WQ...

  2. The deep biosphere in terrestrial sediments in the Chesapeake Bay area, Virginia, USA

    Directory of Open Access Journals (Sweden)

    Anja eBreuker

    2011-07-01

    Full Text Available For the first time quantitative data on the abundance of Bacteria, Archaea and Eukarya in deep terrestrial sediments are provided using multiple methods (total cell counting, quantitative real-time PCR (Q-PCR and catalyzed reporter deposition – fluorescence in situ hybridization (CARD-FISH. The oligotrophic (organic carbon content of ~ 0.2 % deep terrestrial sediments in the Chesapeake Bay area at Eyreville, Virginia, USA, were drilled and sampled up to a depth of 140 m in 2006. The possibility of contamination during drilling was checked using fluorescent microspheres. Total cell counts decreased from 109 to 106 cells per g dry weight (dw within the uppermost 20 m depth, and did not further decrease with depth below. A significant proportion of the total cell counts could be detected with CARD-FISH within the uppermost 7 m depth. The CARD-FISH numbers for Bacteria were about an order of magnitude higher than those for Archaea. The dominance of Bacteria over Archaea was confirmed by Q-PCR. The down core quantitative distribution of prokaryotic and eukaryotic small subunit ribosomal RNA genes as well as functional genes involved in different biogeochemical processes was revealed by Q-PCR for the uppermost 10 m and for 80-140 m depth. Eukarya and the Fe(III- and Mn(IV-reducing bacterial group Geobacteriaceae were almost only found in the uppermost meter (arable soil, where reactive iron was detected in higher amounts. The bacterial candidate division JS-1 and the classes Anaerolineae and Caldilineae of the phylum Chloroflexi, highly abundant in marine sediments, were found up to the maximum sampling depth in high copy numbers at this terrestrial site as well. A similar high abundance of the functional gene cbbL encoding for the large subunit of RubisCO suggests that autotrophic microorganisms could be relevant in addition to heterotrophs. The functional gene aprA of sulfate reducing bacteria was found within distinct layers up to ca. 100 m depth

  3. The deep biosphere in terrestrial sediments in the chesapeake bay area, virginia, USA.

    Science.gov (United States)

    Breuker, Anja; Köweker, Gerrit; Blazejak, Anna; Schippers, Axel

    2011-01-01

    For the first time quantitative data on the abundance of Bacteria, Archaea, and Eukarya in deep terrestrial sediments are provided using multiple methods (total cell counting, quantitative real-time PCR, Q-PCR and catalyzed reporter deposition-fluorescence in situ hybridization, CARD-FISH). The oligotrophic (organic carbon content of ∼0.2%) deep terrestrial sediments in the Chesapeake Bay area at Eyreville, Virginia, USA, were drilled and sampled up to a depth of 140 m in 2006. The possibility of contamination during drilling was checked using fluorescent microspheres. Total cell counts decreased from 10(9) to 10(6) cells/g dry weight within the uppermost 20 m, and did not further decrease with depth below. Within the top 7 m, a significant proportion of the total cell counts could be detected with CARD-FISH. The CARD-FISH numbers for Bacteria were about an order of magnitude higher than those for Archaea. The dominance of Bacteria over Archaea was confirmed by Q-PCR. The down core quantitative distribution of prokaryotic and eukaryotic small subunit ribosomal RNA genes as well as functional genes involved in different biogeochemical processes was revealed by Q-PCR for the uppermost 10 m and for 80-140 m depth. Eukarya and the Fe(III)- and Mn(IV)-reducing bacterial group Geobacteriaceae were almost exclusively found in the uppermost meter (arable soil), where reactive iron was detected in higher amounts. The bacterial candidate division JS-1 and the classes Anaerolineae and Caldilineae of the phylum Chloroflexi, highly abundant in marine sediments, were found up to the maximum sampling depth in high copy numbers at this terrestrial site as well. A similar high abundance of the functional gene cbbL encoding for the large subunit of RubisCO suggests that autotrophic microorganisms could be relevant in addition to heterotrophs. The functional gene aprA of sulfate reducing bacteria was found within distinct layers up to ca. 100 m depth in low copy numbers

  4. Spatial Predictive Modeling and Remote Sensing of Land Use Change in the Chesapeake Bay Watershed

    Science.gov (United States)

    Goetz, Scott J.; Bockstael, Nancy E.; Jantz, Claire A.

    2005-01-01

    This project was focused on modeling the processes by which increasing demand for developed land uses, brought about by changes in the regional economy and the socio-demographics of the region, are translated into a changing spatial pattern of land use. Our study focused on a portion of the Chesapeake Bay Watershed where the spatial patterns of sprawl represent a set of conditions generally prevalent in much of the U.S. Working in the region permitted us access to (i) a time-series of multi-scale and multi-temporal (including historical) satellite imagery and (ii) an established network of collaborating partners and agencies willing to share resources and to utilize developed techniques and model results. In addition, a unique parcel-level tax assessment database and linked parcel boundary maps exists for two counties in the Maryland portion of this region that made it possible to establish a historical cross-section time-series database of parcel level development decisions. Scenario analyses of future land use dynamics provided critical quantitative insight into the impact of alternative land management and policy decisions. These also have been specifically aimed at addressing growth control policies aimed at curbing exurban (sprawl) development. Our initial technical approach included three components: (i) spatial econometric modeling of the development decision, (ii) remote sensing of suburban change and residential land use density, including comparisons of past change from Landsat analyses and more traditional sources, and (iii) linkages between the two through variable initialization and supplementation of parcel level data. To these we added a fourth component, (iv) cellular automata modeling of urbanization, which proved to be a valuable addition to the project. This project has generated both remote sensing and spatially explicit socio-economic data to estimate and calibrate the parameters for two different types of land use change models and has

  5. Tracking Nonpoint Source Nitrogen and Carbon in Watersheds of Chesapeake Bay

    Science.gov (United States)

    Kaushal, S.; Pennino, M. J.; Duan, S.; Blomquist, J.

    2012-12-01

    Humans have altered nitrogen and carbon cycles in rivers regionally with important impacts on coastal ecosystems. Nonpoint source nitrogen pollution is a leading contributor to coastal eutrophication and hypoxia. Shifts in sources of carbon impact downstream ecosystem metabolism and fate and transport of contaminants in coastal zones. We used a combination of stable isotopes and optical tracers to investigate fate and transport of nitrogen and carbon sources in tributaries of the largest estuary in the U.S., the Chesapeake Bay. We analyzed isotopic composition of water samples from major tributaries including the Potomac River, Susquehanna River, Patuxent River, and Choptank River during routine and storm event sampling over multiple years. A positive correlation between δ15N-NO3- and δ18O-NO3- in the Potomac River above Washington D.C. suggested denitrification or biological uptake in the watershed was removing agriculturally-derived N during summer months. In contrast, the Patuxent River in Maryland showed elevated δ15N-NO3- (5 - 12 per mil) with no relationship to δ18O-NO3- suggesting the importance of wastewater sources. From the perspective of carbon sources, there were distinct isotopic values of the δ13C-POM of particulate organic matter and fluorescence excitation emission matrices (EEMS) for rivers influenced by their dominant watershed land use. EEMS showed that there were increases in the humic and fulvic fractions of dissolved organic matter during spring floods, particularly in the Potomac River. Stable isotopic values of δ13C-POM also showed rapid depletion suggesting terrestrial carbon "pulses" in the Potomac River each spring. The δ15N-POM peaked to 10 - 15 per mil each spring suggested a potential manure source or result of biological processing within the watershed. Overall, there were considerable changes in sources and transformations of nitrogen and carbon that varied across rivers and that contribute to nitrogen and carbon loads

  6. Novel Pelagic Iron-Oxidizing Zetaproteobacteria from the Chesapeake Bay Oxic–Anoxic Transition Zone

    Directory of Open Access Journals (Sweden)

    Beverly K. Chiu

    2017-07-01

    Full Text Available Chemolithotrophic iron-oxidizing bacteria (FeOB could theoretically inhabit any environment where Fe(II and O2 (or nitrate coexist. Until recently, marine Fe-oxidizing Zetaproteobacteria had primarily been observed in benthic and subsurface settings, but not redox-stratified water columns. This may be due to the challenges that a pelagic lifestyle would pose for Zetaproteobacteria, given low Fe(II concentrations in modern marine waters and the possibility that Fe oxyhydroxide biominerals could cause cells to sink. However, we recently cultivated Zetaproteobacteria from the Chesapeake Bay oxic–anoxic transition zone, suggesting that they can survive and contribute to biogeochemical cycling in a stratified estuary. Here we describe the isolation, characterization, and genomes of two new species, Mariprofundus aestuarium CP-5 and Mariprofundus ferrinatatus CP-8, which are the first Zetaproteobacteria isolates from a pelagic environment. We looked for adaptations enabling strains CP-5 and CP-8 to overcome the challenges of living in a low Fe redoxcline with frequent O2 fluctuations due to tidal mixing. We found that the CP strains produce distinctive dreadlock-like Fe oxyhydroxide structures that are easily shed, which would help cells maintain suspension in the water column. These oxides are by-products of Fe(II oxidation, likely catalyzed by the putative Fe(II oxidase encoded by the cyc2 gene, present in both CP-5 and CP-8 genomes; the consistent presence of cyc2 in all microaerophilic FeOB and other FeOB genomes supports its putative role in Fe(II oxidation. The CP strains also have two gene clusters associated with biofilm formation (Wsp system and the Widespread Colonization Island that are absent or rare in other Zetaproteobacteria. We propose that biofilm formation enables the CP strains to attach to FeS particles and form flocs, an advantageous strategy for scavenging Fe(II and developing low [O2] microenvironments within more oxygenated

  7. Resiliency of the western Chesapeake Bay to total suspended solid concentrations following storms and accounting for land-cover

    Science.gov (United States)

    Hasan, Mejs; Benninger, Larry

    2017-05-01

    The effect of storms on water quality in the Chesapeake Bay has been studied in a patchwork fashion at various sites for short periods of time. In this paper, we use a relationship between MODIS-Terra red light reflectance and total suspended solid (TSS) concentrations in order to develop a fourteen-year time period of TSS estimates during which effects of storms and land cover can be studied over a large portion of the Bay. Exponential fits were most appropriate, resulting in viable reflectance-TSS relationships for the five major Western Shore rivers and the Mainstem of the Bay. Other tributaries were less well-disposed for such relationships due to lack of a large range of TSS concentrations, shallow river beds, or low number of data points. Treating the entire Chesapeake as a single entity and modeling a single reflectance-TSS relationship for the entire estuary produced poorer models with less significance compared to treating each channel separately. Over 2800 rain events were studied in the Lower Western Shore between 2000 and 2014. We found some evidence that higher rainfall amounts correspond to a lower distribution of TSS concentrations 1 day following the event in forested watersheds. At rainfall events of <50 mm, maximum TSS within one day of the storm was highly variable, suggesting that rainfall amounts alone cannot explain variation in TSS levels. Finally, we found value in the use of prediction intervals around TSS estimates, a statistical procedure uncommonly used heretofore with satellite-based estimates but which can help to determine if results are significant or not.

  8. Wave spectra, meteorological, and other data from NOAA Ship FERREL and other platforms from the Chesapeake Bay from 1983-03-14 to 1983-11-22 (NCEI Accession 8500124)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wave spectra, meteorological, and other data were collected from NOAA Ship FERREL and other platforms in the Chesapeake Bay. Data were collected by the National...

  9. Comparison of MSS and TM Data for Landcover Classification in the Chesapeake Bay Area: a Preliminary Report. [Taylor's Island, Maryland

    Science.gov (United States)

    Mulligan, P. J.; Gervin, J. C.; Lu, Y. C.

    1985-01-01

    An area bordering the Eastern Shore of the Chesapeake Bay was selected for study and classified using unsupervised techniques applied to LANDSAT-2 MSS data and several band combinations of LANDSAT-4 TM data. The accuracies of these Level I land cover classifications were verified using the Taylor's Island USGS 7.5 minute topographic map which was photointerpreted, digitized and rasterized. The the Taylor's Island map, comparing the MSS and TM three band (2 3 4) classifications, the increased resolution of TM produced a small improvement in overall accuracy of 1% correct due primarily to a small improvement, and 1% and 3%, in areas such as water and woodland. This was expected as the MSS data typically produce high accuracies for categories which cover large contiguous areas. However, in the categories covering smaller areas within the map there was generally an improvement of at least 10%. Classification of the important residential category improved 12%, and wetlands were mapped with 11% greater accuracy.

  10. Sources of suspended-sediment flux in streams of the chesapeake bay watershed: A regional application of the sparrow model

    Science.gov (United States)

    Brakebill, J.W.; Ator, S.W.; Schwarz, G.E.

    2010-01-01

    We describe the sources and transport of fluvial suspended sediment in nontidal streams of the Chesapeake Bay watershed and vicinity. We applied SPAtially Referenced Regressions on Watershed attributes, which spatially correlates estimated mean annual flux of suspended sediment in nontidal streams with sources of suspended sediment and transport factors. According to our model, urban development generates on average the greatest amount of suspended sediment per unit area (3,928 Mg/km2/year), although agriculture is much more widespread and is the greatest overall source of suspended sediment (57 Mg/km2/year). Factors affecting sediment transport from uplands to streams include mean basin slope, reservoirs, physiography, and soil permeability. On average, 59% of upland suspended sediment generated is temporarily stored along large rivers draining the Coastal Plain or in reservoirs throughout the watershed. Applying erosion and sediment controls from agriculture and urban development in areas of the northern Piedmont close to the upper Bay, where the combined effects of watershed characteristics on sediment transport have the greatest influence may be most helpful in mitigating sedimentation in the bay and its tributaries. Stream restoration efforts addressing floodplain and bank stabilization and incision may be more effective in smaller, headwater streams outside of the Coastal Plain. ?? 2010 American Water Resources Association. No claim to original U.S. government works.

  11. Phosphorus availability and turnover in the Chesapeake Bay: Insights from nutrient stoichiometry and phosphate oxygen isotope ratios

    Science.gov (United States)

    Li, Jiying; Bai, Yuge; Bear, Kristi; Joshi, Sunendra; Jaisi, Deb

    2017-04-01

    Understanding phosphorus (P) availability and its control on eutrophication in the Chesapeake Bay is complicated by variable sources and biogeochemical reactions transforming P forms. We investigated seasonal and spatial variability in P limitation and biological utilization in the Bay using nutrient stoichiometry (of both dissolved and particulate forms), phosphate oxygen isotope ratios, and alkaline phosphatase activity at three sites along the salinity gradient. We demonstrate that particulate nutrient ratios can be used as indicators of nutrient limitation in the Bay and suggest strong seasonal and spatial variability in P availability: the surface water is P limiting in spring, but this condition is alleviated in summer and in the deeper waters. Variability in P limitation is well reflected in the trends of phosphate oxygen isotope composition (δ18OP), with values approaching isotopic equilibrium under P limiting conditions, suggesting rapid biological P turnover. Furthermore δ18OP values suggest multiple phosphate sources including remobilization of terrestrial inorganic P phases and remineralization of organic P and P from both sources is sufficiently cycled by microorganisms, suggested by the extensive equilibrium oxygen isotope exchange. Our results further suggest high P utilization in the deeper euphotic zone where nutrients are abundant, raising caution on studying nutrient availability and limitation only in the surface water.

  12. Metatranscriptomic analyses of plankton communities inhabiting surface and subpycnocline waters of the Chesapeake Bay during oxic-anoxic-oxic transitions.

    Science.gov (United States)

    Hewson, Ian; Eggleston, Erin M; Doherty, Mary; Lee, Dong Yoon; Owens, Michael; Shapleigh, James P; Cornwell, Jeffrey C; Crump, Byron C

    2014-01-01

    We used metatranscriptomics to study the gene transcription patterns of microbial plankton (0.2 to 64 μm) at a mesohaline station in the Chesapeake Bay under transitions from oxic to anoxic waters in spring and from anoxic to oxic waters in autumn. Samples were collected from surface (i.e., above pycnocline) waters (3 m) and from waters beneath the pycnocline (16 to 22 m) in both 2010 and 2011. Metatranscriptome profiles based on function and potential phylogeny were different between 2010 and 2011 and strongly variable in 2011. This difference in variability corresponded with a highly variable ratio of eukaryotic to bacterial sequences (0.3 to 5.5), reflecting transient algal blooms in 2011 that were absent in 2010. The similarity between metatranscriptomes changed at a lower rate during the transition from oxic to anoxic waters than after the return to oxic conditions. Transcripts related to photosynthesis and low-affinity cytochrome oxidases were significantly higher in shallow than in deep waters, while in deep water genes involved in anaerobic metabolism, particularly sulfate reduction, succinyl coenzyme A (succinyl-CoA)-to-propionyl-CoA conversion, and menaquinone synthesis, were enriched relative to in shallow waters. Expected transitions in metabolism between oxic and anoxic deep waters were reflected in elevated levels of anaerobic respiratory reductases and utilization of propenediol and acetoin. The percentage of archaeal transcripts increased in both years in late summer (from 0.1 to 4.4% of all transcripts in 2010 and from 0.1 to 6.2% in 2011). Denitrification-related genes were expressed in a predicted pattern during the oxic-anoxic transition. Overall, our data suggest that Chesapeake Bay microbial assemblages express gene suites differently in shallow and deep waters and that differences in deep waters reflect variable redox states.

  13. Concentration, distribution, and bioavailability of mercury and methylmercury in sediments of Baltimore Harbor and Chesapeake Bay, Maryland, USA

    Energy Technology Data Exchange (ETDEWEB)

    Mason, R.P.; Lawrence, A.L.

    1999-11-01

    For the Chesapeake Bay, sediments in regions such as Baltimore Harbor have total mercury (Hg) concentrations that exceed environmental effects guidelines. However, fish concentrations do not appear elevated. Indeed, the factors controlling the transfer of sedimentary Hg, especially as monomethylmercury (MMHg), the most bioaccumulative form of Hg, to these aquatic organisms are poorly understood. To examine this, the authors have investigated the distribution and bioavailability of Hg and MMHg to benthic organisms in Baltimore harbor and the Chesapeake Bay, in Maryland, USA. The results discussed here show that sediment concentration for both total Hg and MMHg covaries with sediment organic content and that this parameter is a better predictor, for surface sediments, of concentration than iron content, acid volatile sulfide (AVS), or other factors. Furthermore, correlations between inorganic Hg and MMHg in benthic biota with sediment levels suggest that variation in the bioaccumulation factor (SBAF) for invertebrates is best explained in terms of sediment organic content. thus, the results from this study emphasize the importance of organic matter in regions removed from point source input in controlling both the concentration and bioavailability of MMHg to organisms. Because of the exponential nature of the SBAF/organic content relationship, there is a nonlinear organism response to MMHg in sediments that must be considered in any estimation of the toxic effect of sediment MMHg. Also, as a result of the decoupling between total Hg and MMHg concentration and bioavailability in surface sediments, any remediation evaluation of bioavailability and/or toxicity that is based only on total Hg concentration is unlikely to provide a reliable prediction.

  14. Uptake of Trace Elements in Aragonitic Otoliths of an Estuarine Dependent Fish, Spotted Seatrout, from surface waters of Chesapeake Bay.

    Science.gov (United States)

    Dorval, E.; Jones, C.; Hannigan, R.; Sako, A.

    2002-05-01

    Seagrass beds in Chesapeake Bay are critical habitats for early life stages of Spotted seatrout, {\\Cynoscion nebulosus}. Spotted seatrout spawn in surface waters in the Bay during late spring and thereafter their larvae settle in seagrass beds where the juveniles spend three to four months. These habitats provide refuge and food for larvae and juveniles, influencing growth, mortality, and survival rates. Identification of essential seagrass habitats for estuarine-dependent fish is of primary importance given the current decline in habitat quality. We hypothesized that the geochemistry of surface waters in Chesapeake Bay is different along both the latitudinal and longitudinal gradients, and that we could use trace elements in otoliths as a natural tag to differentiate survivors among seagrass beds. We investigated the relationship between water and otolith trace element chemistry and we present here some preliminary results. From July to September 2001 we collected surface waters during spring tide from seagrass beds and around the mouth of the Potomac, Rappahannock, and York river. Waters were filtered through a 0.45 uM filter and acidified to pH < 2 with ultrapure nitric acid. In September, we collected juvenile fish in seagrass beds along the Western and Eastern shores, Tangier and Smith Islands. From each individual fish one sagittal otolith was extracted, cleaned with milli-Q water, soaked for 5 minutes in ultrapure hydrogen peroxide, rinsed, and sonicated. All dried and cleaned otoliths were dissolved in ultrapure nitric acid. We used trace metal clean procedures to process both water and otoliths and trace elements were measured by sector field ICP-MS. Both waters and otoliths showed distinct chemical signatures among seagrass beds, and samples could be classified with high accuracy to their respective sites of collection. For most seagrass beds Ba/Ca, Rb/Ca, V/Ca showed inverse relationship between water and otolith whereas Sr/Ca was positively correlated

  15. Chesapeake Bay Low Freshwater Inflow Study. Biota Assessment. Phase II. Main Report.

    Science.gov (United States)

    1982-05-01

    Palaemonetes pugio - grass shrimp Brevoortia tyrannus - menhaden larvae and juveniles Anchoa mitchilli - Bay anchovy, eggs Anchoa mitchilli - Bay anchovy...polypsI’. __,___ __ Mercenaria mercenaria - larvae Callinectes sapidus - spawning area Brevoort(a tyrannus - larvae and juveniles Alosa sapidissima

  16. The Eocene-Oligocene sedimentary record in the Chesapeake Bay impact structure: Implications for climate and sea-level changes on the western Atlantic margin

    Science.gov (United States)

    Schulte, P.; Wade, B.S.; Kontny, A.; ,

    2009-01-01

    A multidisciplinary investigation of the Eocene-Oligocene transition in the International Continental Scientific Drilling Program (ICDP)-U.S. Geological Survey (USGS) Eyreville core from the Chesapeake Bay impact basin was conducted in order to document environmental changes and sequence stratigraphic setting. Planktonic foraminifera and calcareous nannofossil biostratigraphy indicate that the Eyreville core includes an expanded upper Eocene (Biozones E15 to E16 and NP19/20 to NP21, respectively) and a condensed Oligocene-Miocene (NP24-NN1) sedimentary sequence. The Eocene-Oligocene contact corresponds to a =3-Ma-long hiatus. Eocene- Oligocene sedimentation is dominated by great diversity and varying amounts of detrital and authigenic minerals. Four sedimentary intervals are identified by lithology and mineral content: (1) A 30-m-thick, smectite- and illite-rich interval directly overlies the Exmore Formation, suggesting long-term reworking of impact debris within the Chesapeake Bay impact structure. (2) Subsequently, an increase in kaolinite content suggests erosion from soils developed during late Eocene warm and humid climate in agreement with data derived from other Atlantic sites. However, the kaolinite increase may also be explained by change to a predominant sediment input from outside the Chesapeake Bay impact structure caused by progradation of more proximal facies belts during the highstand systems tract of the late Eocene sequence E10.Spectral analysis based on gamma-ray and magnetic susceptibility logs suggests infl uence of 1.2 Ma low-amplitude oscillation of the obliquity period during the late Eocene. (3) During the latest Eocene (Biozones NP21 and E16), several lithological contacts (clay to clayey silt) occur concomitant with a prominent change in the mineralogical composition with illite as a major component: This lithological change starts close to the Biozone NP19/20-NP21 boundary and may correspond to sequence boundary E10-E11 as observed in

  17. Chesapeake Bay Tidal Flooding Study. Appendix A. Problem Identification. Appendix B. Plan Formulation, Assessment and Evaluation. Appendix C. Recreation and Natural Resources.

    Science.gov (United States)

    1984-09-01

    MEMORIA is ayA FIUR A-3 POTOT AREA PLYAL Y’AGS 93 URCN SA ~ ~ 110r T6RV made to eliminate the Scott’s Creek area and make a tie-out at Glasgow and Godwin...or near prime recreation areas. Both Maryland and Virginia have on-going programs relative to this form of pollution. BAY BIOTA The stinging sea...and development for swimming. However, the large undeveloped areas and frontage on both the Atlantic Ocean and the Chesapeake Bay make them of prime

  18. Seasonal Phytoplankton Composition and Concentrations in the Lower Chesapeake Bay and Vicinity.

    Science.gov (United States)

    1984-03-31

    and Willoughby Bay collections. A more extensive list of cyanobacteria ( cyanophyta ) in the plankton were noted in the lower Bay and in the Bay plume...Dinophyceae (61), Haptophyceae (Prymnesio- phyceae) (6), Cyanobacteria (Cyanophyceae) (9), Euglenophyceae (6), Chlorophyceae (11), Cryptophyceae (4...into three size categories (ɛ, 3-5, and 6-10 um), they represent a mixture of mainly cyanobacteria (cyanophyceae) and nonflagellated chlorophytes. i

  19. Late Pleistocene eolian features in southeastern Maryland and Chesapeake Bay region indicate strong WNW-NW winds accompanied growth of the Laurentide Ice Sheet

    Science.gov (United States)

    Markewich, H.W.; Litwin, R.J.; Pavich, M.J.; Brook, G.A.

    2009-01-01

    Inactive parabolic dunes are present in southeastern Maryland, USA, along the east bank of the Potomac River. More elongate and finer-grained eolian deposits and paha-like ridges characterize the Potomac River-Patuxent River upland and the west side of Chesapeake Bay. These ridges are streamlined erosional features, veneered with eolian sediment and interspersed with dunes in the low-relief headwaters of Potomac- and Patuxent-river tributaries. Axis data for the dunes and ridges indicate formation by WNW-NW winds. Optically stimulated luminescence and radiocarbon age data suggest dune formation from ??? 33-15??ka, agreeing with the 30-13??ka ages Denny, C.S., Owens, J.P., Sirkin, L., Rubin, M., 1979. The Parsonburg Sand in the central Delmarva Peninsula, Maryland and Delaware. U.S. Geol. Surv. Prof. Pap. 1067-B, 16??pp. suggested for eolian deposits east of Chesapeake Bay. Age range and paleowind direction(s) for eolian features in the Bay region approximate those for late Wisconsin loess in the North American midcontinent. Formation of midcontinent loess and Bay-region eolian features was coeval with rapid growth of the Laurentide Ice Sheet and strong cooling episodes (??18O minima) evident in Greenland ice cores. Age and paleowind-direction coincidence, for eolian features in the midcontinent and Bay region, indicates strong mid-latitude WNW-NW winds for several hundred kilometers south of the Laurentide glacial terminus that were oblique to previously simulated anticyclonic winds for the last glacial maximum.

  20. Application of a Weighted Regression Model for Reporting Nutrient and Sediment Concentrations, Fluxes, and Trends in Concentration and Flux for the Chesapeake Bay Nontidal Water-Quality Monitoring Network, Results Through Water Year 2012

    Science.gov (United States)

    Chanat, Jeffrey G.; Moyer, Douglas L.; Blomquist, Joel D.; Hyer, Kenneth E.; Langland, Michael J.

    2016-01-13

    In the Chesapeake Bay watershed, estimated fluxes of nutrients and sediment from the bay’s nontidal tributaries into the estuary are the foundation of decision making to meet reductions prescribed by the Chesapeake Bay Total Maximum Daily Load (TMDL) and are often the basis for refining scientific understanding of the watershed-scale processes that influence the delivery of these constituents to the bay. Two regression-based flux and trend estimation models, ESTIMATOR and Weighted Regressions on Time, Discharge, and Season (WRTDS), were compared using data from 80 watersheds in the Chesapeake Bay Nontidal Water-Quality Monitoring Network (CBNTN). The watersheds range in size from 62 to 70,189 square kilometers and record lengths range from 6 to 28 years. ESTIMATOR is a constant-parameter model that estimates trends only in concentration; WRTDS uses variable parameters estimated with weighted regression, and estimates trends in both concentration and flux. WRTDS had greater explanatory power than ESTIMATOR, with the greatest degree of improvement evident for records longer than 25 years (30 stations; improvement in median model R2= 0.06 for total nitrogen, 0.08 for total phosphorus, and 0.05 for sediment) and the least degree of improvement for records of less than 10 years, for which the two models performed nearly equally. Flux bias statistics were comparable or lower (more favorable) for WRTDS for any record length; for 30 stations with records longer than 25 years, the greatest degree of improvement was evident for sediment (decrease of 0.17 in median statistic) and total phosphorus (decrease of 0.05). The overall between-station pattern in concentration trend direction and magnitude for all constituents was roughly similar for both models. A detailed case study revealed that trends in concentration estimated by WRTDS can operationally be viewed as a less-constrained equivalent to trends in concentration estimated by ESTIMATOR. Estimates of annual mean flow

  1. Birth of the modern Chesapeake Bay estuary between 7.4 and 8.2 ka and implications for global seal-level rise

    Science.gov (United States)

    Bratton, J.F.; Colman, Steven M.; Thieler, E.R.; Seal, R.R.

    2003-01-01

    Two major pulses of sea-level rise are thought to have taken place since the last glacial maximum - meltwater pulses (mwp) 1A (12 cal ka) and 1B (9.5 cal ka). Between mwp 1B and about 6 cal ka, many of the complex coastal ecosystem which ring the world's oceans began to form. Here we report data for rhenium, carbon isotopes, total organic carbon, and fossil oysters from Chesapeake Bay which span the transition from fresh to brackish water conditions in the bay in the mid-Holocene. These data constrain sea-level change and resulting environmental change in the bay. They indicate that the transition was rapid, and that it was produced by (1) a third pulse of rapid eustatic sea-level rise, or (2) a geometry of the prehistoric Chesapeake Bay basin which predisposed it to a nonlinear response to a steadily rising sea level. Similar nonlinear changes in vulnerable coastal environments are likely to take place in the future due to polar warming, regardless of the timing or rate of sea-level rise.

  2. Birth of the modern Chesapeake Bay estuary between 7.4 and 8.2 ka and implications for global sea-level rise

    Science.gov (United States)

    Bratton, John F.; Colman, Steven M.; Thieler, E. Robert; Seal, Robert R.

    2002-12-01

    Two major pulses of sea-level rise are thought to have taken place since the last glacial maximum — meltwater pulses (mwp) 1A (12 cal ka) and 1B (9.5 cal ka). Between mwp 1B and about 6 cal ka, many of the complex coastal ecosystems which ring the world's oceans began to form. Here we report data for rhenium, carbon isotopes, total organic carbon, and fossil oysters from Chesapeake Bay which span the transition from fresh to brackish water conditions in the bay in the mid-Holocene. These data constrain sea-level change and resulting environmental change in the bay. They indicate that the transition was rapid, and that it was produced by (1) a third pulse of rapid eustatic sea-level rise, or (2) a geometry of the prehistoric Chesapeake Bay basin which predisposed it to a nonlinear response to a steadily rising sea level. Similar nonlinear changes in vulnerable coastal environments are likely to take place in the future due to polar warming, regardless of the timing or rate of sea-level rise.

  3. Microbial abundance in the deep subsurface of the Chesapeake Bay impact crater: Relationship to lithology and impact processes

    Science.gov (United States)

    Cockell, Charles S.; Gronstal, Aaron L.; Voytek, Mary A.; Kirshtein, Julie D.; Finster, Kai; Sanford, Ward E.; Glamoclija, Mihaela; Gohn, Gregroy S.; Powars, David S.; Horton, J. Wright

    2009-01-01

    Asteroid and comet impact events are known to cause profound disruption to surface ecosystems. The aseptic collection of samples throughout a 1.76-km-deep set of cores recovered from the deep subsurface of the Chesapeake Bay impact structure has allowed the study of the subsurface biosphere in a region disrupted by an impactor. Microbiological enumerations suggest the presence of three major microbiological zones. The upper zone (127–867 m) is characterized by a logarithmic decline in microbial abundance from the surface through the postimpact section of Miocene to Upper Eocene marine sediments and across the transition into the upper layers of the impact tsunami resurge sediments and sediment megablocks. In the middle zone (867–1397 m) microbial abundances are below detection. This zone is predominantly quartz sand, primarily composed of boulders and blocks, and it may have been mostly sterilized by the thermal pulse delivered during impact. No samples were collected from the large granite block (1096–1371 m). The lowest zone (below 1397 m) of increasing microbial abundance coincides with a region of heavily impact-fractured, hydraulically conductive suevite and fractured schist. These zones correspond to lithologies influenced by impact processes. Our results yield insights into the influence of impacts on the deep subsurface biosphere.

  4. NASA-modified precipitation products to improve USEPA nonpoint source water quality modeling for the Chesapeake Bay.

    Science.gov (United States)

    Nigro, Joseph; Toll, David; Partington, Ed; Ni-Meister, Wenge; Lee, Shihyan; Gutierrez-Magness, Angelica; Engman, Ted; Arsenault, Kristi

    2010-01-01

    The USEPA has estimated that over 20,000 water bodies within the United States do not meet water quality standards. One of the regulations in the Clean Water Act of 1972 requires states to monitor the total maximum daily load, or the amount of pollution that can be carried by a water body before it is determined to be "polluted," for any watershed in the United States (Copeland, 2005). In response to this mandate, the USEPA developed Better Assessment Science Integrating Nonpoint Sources (BASINS) as a decision support tool for assessing pollution and to guide the decision-making process for improving water quality. One of the models in BASINS, the Hydrological Simulation Program-Fortran (HSPF), computes continuous streamflow rates and pollutant concentration at each basin outlet. By design, precipitation and other meteorological data from weather stations serve as standard model input. In practice, these stations may be unable to capture the spatial heterogeneity of precipitation events, especially if they are few and far between. An attempt was made to resolve this issue by substituting station data with NASA-modified/NOAA precipitation data. Using these data within HSPF, streamflow was calculated for seven watersheds in the Chesapeake Bay Basin during low flow periods, convective storm periods, and annual flows. In almost every case, the modeling performance of HSPF increased when using the NASA-modified precipitation data, resulting in better streamflow statistics and, potentially, in improved water quality assessment.

  5. Climate Change Effects on Respiration Rates of Blue Crab (Callinectes sapidus) from the Patuxent River, Chesapeake Bay

    Science.gov (United States)

    Nyffeler, A.

    2016-02-01

    A rise in atmospheric CO2 induces a greenhouse effect that also causes ocean temperatures and CO2 levels to rise. These environmental changes may represent an additional energetic cost for blue crabs because they rely on the concentration of CO2 in the water to deposit calcium carbonate in their shells. We conducted a respiration experiment to measure the effect of climate change on crab metabolism. Crabs were collected from the Chesapeake Bay and exposed to different heated and acidified conditions. After crabs had been exposed to the environmental conditions in the chambers for two molts, they were placed in respiration chambers to measure rates of oxygen consumption. Results indicated different trends in respiration rates between the treatments, although the patterns were not statistically significant. Crabs exposed to higher temperatures showed elevated respiration rates, while crabs exposed to high CO2 demonstrated decreased respiration rates. The two factors of climate change (high temperature and high CO2) did not demonstrate the highest respiration rate, but rather the crabs exposed to high temperatures and ambient CO2 showed the highest mean respiration rate. These data suggest that crab metabolism may not change as much as expected due to climate changes.

  6. Decadal re-evaluation of contaminant exposure and productivity of ospreys (Pandion haliaetus) nesting in Chesapeake Bay Regions of Concern

    Science.gov (United States)

    Lazarus, Rebecca; Rattner, Barnett A.; McGowan, Peter C.; Hale, Robert C.; Schultz, Sandra; Karouna, Natalie; Ottinger, Mary Ann

    2015-01-01

    The last large-scale ecotoxicological study of ospreys (Pandion haliaetus) in Chesapeake Bay was conducted in 2000-2001 and focused on U.S. EPA-designated Regions of Concern (ROCs; Baltimore Harbor/Patapsco, Anacostia/middle Potomac, and Elizabeth Rivers). In 2011-2012, ROCs were re-evaluated to determine spatial and temporal trends in productivity and contaminants. Concentrations of p,p'-DDE were low in eggs and below the threshold associated with eggshell thinning. Eggs from the Anacostia/middle Potomac Rivers had lower total PCB concentrations in 2011 than in 2000; however, concentrations remained unchanged in Baltimore Harbor. Polybrominated diphenyl ether flame retardants declined by 40%, and five alternative brominated flame retardants were detected at low levels. Osprey productivity was adequate to sustain local populations, and there was no relation between productivity and halogenated contaminants. Our findings document continued recovery of the osprey population, declining levels of many persistent halogenated compounds, and modest evidence of genetic damage in nestlings from industrialized regions.

  7. Increased terrestrial to ocean sediment and carbon fluxes in the northern Chesapeake Bay associated with twentieth century land alteration

    Science.gov (United States)

    Saenger, C.; Cronin, T. M.; Willard, D.; Halka, J.; Kerhin, R.

    2008-01-01

    We calculated Chesapeake Bay (CB) sediment and carbon fluxes before and after major anthropogenic land clearance using robust monitoring, modeling and sedimentary data. Four distinct fluxes in the estuarine system were considered including (1) the flux of eroded material from the watershed to streams, (2) the flux of suspended sediment at river fall lines, (3) the burial flux in tributary sediments, and (4) the burial flux in main CB sediments. The sedimentary maximum in Ambrosia (ragweed) pollen marked peak land clearance (~1900 a.d.). Rivers feeding CB had a total organic carbon (TOC)/total suspended solids of 0.24??0.12, and we used this observation to calculate TOC fluxes from sediment fluxes. Sediment and carbon fluxes increased by 138-269% across all four regions after land clearance. Our results demonstrate that sediment delivery to CB is subject to significant lags and that excess post-land clearance sediment loads have not reached the ocean. Post-land clearance increases in erosional flux from watersheds, and burial in estuaries are important processes that must be considered to calculate accurate global sediment and carbon budgets. ?? 2008 Coastal and Estuarine Research Federation.

  8. Mycobacterium pseudoshottsii sp. nov., a slowly growing chromogenic species isolated from Chesapeake Bay striped bass (Morone saxatilis)

    Science.gov (United States)

    Rhodes, M.W.; Kator, H.; McNabb, A.; Deshayes, C.; Reyrat, J.-M.; Brown-Elliott, B. A.; Wallace, R.; Trott, K.A.; Parker, J.M.; Lifland, B.; Osterhout, G.; Kaattari, I.; Reece, K.; Vogelbein, W.; Ottinger, C.A.

    2005-01-01

    A group of slowly growing photochromogenic mycobacteria was isolated from Chesapeake Bay striped bass (Morone saxatilis) during an epizootic of mycobacteriosis. Growth characteristics, acid-fastness and 16S rRNA gene sequencing results were consistent with those of the genus Mycobacterium. Biochemical reactions, growth characteristics and mycolic acid profiles (HPLC) resembled those of Mycobacterium shottsii, a non-pigmented mycobacterium also isolated during the same epizootic. Sequencing of the 16S rRNA genes, the gene encoding the exported repeated protein (erp) and the gene encoding the 65 kDa heat-shock protein (hsp65) and restriction enzyme analysis of the hsp65 gene demonstrated that this group of isolates is unique. Insertion sequences associated with Mycobacterium ulcerans, IS2404 and IS2606, were detected by PCR. These isolates could be differentiated from other slowly growing pigmented mycobacteria by their inability to grow at 37 ??C, production of niacin and urease, absence of nitrate reductase, negative Tween 80 hydrolysis and resistance to isoniazid (1 ??g ml-1), p-nitrobenzoic acid, thiacetazone and thiophene-2-carboxylic hydrazide. On the basis of this polyphasic study, it is proposed that these isolates represent a novel species, Mycobacterium pseudoshottsii sp. nov. The type strain, L15T, has been deposited in the American Type Culture Collection as ATCC BAA-883T and the National Collection of Type Cultures (UK) as NCTC 13318T. ?? 2005 IUMS.

  9. The Effect of Dissolved Polyunsaturated Aldehydes on Microzooplankton Growth Rates in the Chesapeake Bay and Atlantic Coastal Waters

    Directory of Open Access Journals (Sweden)

    Peter J. Lavrentyev

    2015-05-01

    Full Text Available Allelopathy is wide spread among marine phytoplankton, including diatoms, which can produce cytotoxic secondary metabolites such as polyunsaturated aldehydes (PUA. Most studies on diatom-produced PUA have been dedicated to their inhibitory effects on reproduction and development of marine invertebrates. However, little information exists on their impact on key herbivores in the ocean, microzooplankton. This study examined the effects of dissolved 2E,4E-octadienal and 2E,4E-heptadienal on the growth rates of natural ciliate and dinoflagellate populations in the Chesapeake Bay and the coastal Atlantic waters. The overall effect of PUA on microzooplankton growth was negative, especially at the higher concentrations, but there were pronounced differences in response among common planktonic species. For example, the growth of Codonella sp., Leegaardiella sol, Prorodon sp., and Gyrodinium spirale was impaired at 2 nM, whereas Strombidium conicum, Cyclotrichium gigas, and Gymnodinium sp. were not affected even at 20 nM. These results indicate that PUA can induce changes in microzooplankton dynamics and species composition.

  10. Remote sensing of submerged aquatic vegetation in lower Chesapeake Bay - A comparison of Landsat MSS to TM imagery

    Science.gov (United States)

    Ackleson, S. G.; Klemas, V.

    1987-01-01

    Landsat MSS and TM imagery, obtained simultaneously over Guinea Marsh, VA, as analyzed and compares for its ability to detect submerged aquatic vegetation (SAV). An unsupervised clustering algorithm was applied to each image, where the input classification parameters are defined as functions of apparent sensor noise. Class confidence and accuracy were computed for all water areas by comparing the classified images, pixel-by-pixel, to rasterized SAV distributions derived from color aerial photography. To illustrate the effect of water depth on classification error, areas of depth greater than 1.9 m were masked, and class confidence and accuracy recalculated. A single-scattering radiative-transfer model is used to illustrate how percent canopy cover and water depth affect the volume reflectance from a water column containing SAV. For a submerged canopy that is morphologically and optically similar to Zostera marina inhabiting Lower Chesapeake Bay, dense canopies may be isolated by masking optically deep water. For less dense canopies, the effect of increasing water depth is to increase the apparent percent crown cover, which may result in classification error.

  11. Rapid, storm-induced changes in the natural abundance of 15N in a planktonic ecosystem, Chesapeake Bay, USA

    Science.gov (United States)

    Montoya, J. P.; Korrigan, S. G.; McCarthy, J. J.

    1991-12-01

    Samples of dissolved inorganic nitrogen (DIN), particulate nitrogen (PN) and two species of Zooplankton were collected during two north-south transects of the Chesapeake Bay in the autumn of 1984 (27-28 September and 3-5 October). During the first transect, the natural abundance of 15N ( δ15N) in the major dissolved and planktonic pools of nitrogen suggested that the δ15N of PN was largely determined by isotopic fractionation during uptake of NH 4+ by phytoplankton. Averaged over the transect as a whole, the δ15N of the herbivorous calanoid copepod Acartia tonsa was 4.1‰ higher than that of the PN, while the δ15N of the carnivorous ctenophore Mnemiopsis leidyi was 6.4‰ higher than that of the PN. In the interval between the two transects, storm-induced mixing of the water column resulted in the injection of NH 4+ into the surface layer of the bay. This perturbation in the estuarine nitrogen cycle resulted in marked changes in the δ15N of the major dissolved and planktonic pools of nitrogen in the bay. In combination with ancillary physical, chemical and biological data, these changes in δ15N provided estimates of the isotopic fractionation factor for NH 4+ uptake by phytoplankton ( α = 1.0065 -1.0080) as well as the turnover time of nitrogen in Acartia tonsa (6.0-9.6 days). Despite the changes in δ15N observed during this cruise, the relative distribution of 15N between trophic levels was preserved: during the second transect, the difference in δ15N between Acartia tonsa and PN was 3.6‰ and the difference in δ15N between Mnemiopsis leidyi and PN was 7.3‰. These results demonstrate that the natural abundance of 15N can change dramatically on a time scale of days and that time-series studies of the natural abundance of 15N can be a useful complement to studies using tracer additions of 15N to document nitrogen transformations in planktonic ecosystems.

  12. Influence of top-down control in the plankton food web on vertical carbon flux: a mesocosm study in the Chesapeake Bay

    Science.gov (United States)

    Stone, J.; Steinberg, D. K.

    2016-02-01

    The effects of predation on carbon export in planktonic food webs are poorly known, but likely play a key role in the biological pump. Gelatinous zooplankton (GZ) dominate the zooplankton community in the Chesapeake Bay during summer months, exerting considerable top-down control on the planktonic food web. The medusa Chrysaora quinquecirrha preys upon the ctenophore Mnemiopsis leidyi, which in turn is a major predator of the omnivorous copepod Acartia tonsa. This trophic cascade is known to significantly affect copepod abundance in Chesapeake Bay, but the resulting changes to particulate organic carbon (POC) flux are unknown. We hypothesized that additions or exclusions of GZ predators would result in changes in both total POC flux and the composition of exported particles (e.g., phytoplankton aggregates, fecal pellets). We conducted mesocosm experiments in the York River tributary of Chesapeake Bay during summer and fall, 2015 to quantify the cascading effects of GZ blooms on POC flux. The mesocosms contained a natural assemblage of phytoplankton and microzooplankton, and A. tonsa copepods, and received one of four treatments of GZ: 1) a control with no GZ added, 2) addition of ctenophores, 3) addition of medusae, and 4) addition of both ctenophores and medusae. POC flux from each mesocosm was measured over multiple 2-day experimental runs and grazing rates of GZ on each other and on copepods were calculated. There were no significant differences in total POC flux between treatments, but the composition of both the final zooplankton assemblage and exported organic matter differed between treatments. As a result of grazing on copepods by ctenophores, treatments which included GZ had lower final copepod abundances and a corresponding decrease in flux of copepod fecal pellets. We discuss how this change in composition of exported material as a result of cascading trophic interactions may affect the efficiency of the biological pump and benthic processes.

  13. Rock-avalanche and ocean-resurge deposits in the late Eocene Chesapeake Bay impact structure: Evidence from the ICDP-USGS Eyreville cores, Virginia, USA

    Science.gov (United States)

    Gohn, G.S.; Powars, D.S.; Dypvik, H.; Edwards, L.E.

    2009-01-01

    An unusually thick section of sedimentary breccias dominated by target-sediment clasts is a distinctive feature of the late Eocene Chesapeake Bay impact structure. A cored 1766-m-deep section recovered from the central part of this marine-target structure by the International Continental Scientific Drilling Program (ICDP)-U.S. Geological Survey (USGS) drilling project contains 678 m of these breccias and associated sediments and an intervening 275-m-thick granite slab. Two sedimentary breccia units consist almost entirely of Cretaceous nonmarine sediments derived from the lower part of the target sediment layer. These sediments are present as coherent clasts and as autoclastic matrix between the clasts. Primary (Cretaceous) sedimentary structures are well preserved in some clasts, and liquefaction and fluidization structures produced at the site of deposition occur in the clasts and matrix. These sedimentary breccias are interpreted as one or more rock avalanches from the upper part of the transient-cavity wall. The little-deformed, unshocked granite slab probably was transported as part of an extremely large slide or avalanche. Water-saturated Cretaceous quartz sand below the slab was transported into the seafloor crater prior to, or concurrently with, the granite slab. Two sedimentary breccia units consist of polymict diamictons that contain cobbles, boulders, and blocks of Cretaceous nonmarine target sediments and less common shocked-rock and melt ejecta in an unsorted, unstratified, muddy, fossiliferous, glauconitic quartz matrix. Much of the matrix material was derived from Upper Cretaceous and Paleogene marine target sediments. These units are interpreted as the deposits of debris flows initiated by the resurge of ocean water into the seafloor crater. Interlayering of avalanche and debris-flow units indicates a partial temporal overlap of the earlier avalanche and later resurge processes. A thin unit of stratified turbidite deposits and overlying laminated

  14. Effects of forested floodplain soil properties on phosphorous concentrations in two Chesapeake Bay sub-watersheds, Virginia, USA.

    Science.gov (United States)

    Odhiambo, B K; Ricker, M C; Le Blanc, L M; Moxey, K A

    2016-08-01

    Aquatic ecosystems are known to undergo fluctuations in nutrient levels as a result of both natural and anthropogenic processes. Changes in both extrinsic and intrinsic fluvial dynamics necessitate constant monitoring as anthropogenic alterations exert new pressures to previously stable river basins. In this study, we analyzed stream water and riparian zone soil phosphorous (P) dynamics in two third-order sub-watersheds of the lower Chesapeake Bay in Virginia, USA. The Ni River is predominantly forested (70 % forested), and Sugarland Run is a more human impacted (>45 % impervious surfaces) sub-watershed located in the suburbs of Washington D.C. Total stream P concentrations were measured during both high and low flows and Mehlich-3 methods were used to evaluate potential P fluxes in riparian soils. The results show total stream P concentrations in Sugarland Run ranged from 0.002 to 0.20 ppm, with an average of 0.054 ppm. In contrast, the forested Ni River had typical stream P concentrations erosion rates and corresponding cut-bank P flux rates were estimated to be 7.98 cm year(-1) and 361 kg P year(-1) for Ni River and 9.84 cm year(-1) and 11,600 kg P year(-1) for Sugarland Run, respectively. The significantly higher values of total P in the stream water and floodplain cut-banks of Sugarland Run suggests erosion and resuspension of previously deposited legacy sediments is an important processes in this human-impacted basin.

  15. Evolution of crystalline target rocks and impactites in the chesapeake bay impact structure, ICDP-USGS eyreville B core

    Science.gov (United States)

    Horton, J.W.; Kunk, M.J.; Belkin, H.E.; Aleinikoff, J.N.; Jackson, J.C.; Chou, I.-Ming

    2009-01-01

    The 1766-m-deep Eyreville B core from the late Eocene Chesapeake Bay impact structure includes, in ascending order, a lower basement-derived section of schist and pegmatitic granite with impact breccia dikes, polymict impact breccias, and cataclas tic gneiss blocks overlain by suevites and clast-rich impact melt rocks, sand with an amphibolite block and lithic boulders, and a 275-m-thick granite slab overlain by crater-fill sediments and postimpact strata. Graphite-rich cataclasite marks a detachment fault atop the lower basement-derived section. Overlying impactites consist mainly of basement-derived clasts and impact melt particles, and coastalplain sediment clasts are underrepresented. Shocked quartz is common, and coesite and reidite are confirmed by Raman spectra. Silicate glasses have textures indicating immiscible melts at quench, and they are partly altered to smectite. Chrome spinel, baddeleyite, and corundum in silicate glass indicate high-temperature crystallization under silica undersaturation. Clast-rich impact melt rocks contain ??- cristobalite and monoclinic tridymite. The impactites record an upward transition from slumped ground surge to melt-rich fallback from the ejecta plume. Basement-derived rocks include amphibolite-facies schists, greenschist(?)-facies quartz-feldspar gneiss blocks and subgreenschist-facies shale and siltstone clasts in polymict impact breccias, the amphibolite block, and the granite slab. The granite slab, underlying sand, and amphibolite block represent rock avalanches from inward collapse of unshocked bedrock around the transient crater rim. Gneissic and massive granites in the slab yield U-Pb sensitive high-resolution ion microprobe (SHRIMP) zircon dates of 615 ?? 7 Ma and 254 ?? 3 Ma, respectively. Postimpact heating was 7lt;~350 ??C in the lower basementderived section based on undisturbed 40Ar/ 39Ar plateau ages of muscovite and <~150

  16. Supporting Coastal Management Decisions in the Face of Sea-Level Rise: Case Study for the Chesapeake Bay Region

    Science.gov (United States)

    Staudt, A. C.; Glick, P.; Clough, J. S.; Nunley, B.

    2008-12-01

    Sea-level rise needs to be a major consideration in regional coastal management and ecological restoration plans. The National Wildlife Federation has initiated a multi-pronged strategy for assisting decision makers at government agencies that manage near-shore ecosystems in several vulnerable coastal regions. Results from our work in the Chesapeake Bay region will be presented. This strategy involves: (1) Detailed modeling of how coastal habitats will migrate in response to a range of sea-level rise scenarios. For this work, we used the Sea Level Affecting Marshes Model (SLAMM), which simulates the dominant processes involved in wetland conversions and shoreline modifications during long-term sea-level rise and takes into consideration localized changes in land elevation due to geological and ecological factors. These model results provide specific information about the locations that are likely to experience shifts in coastal marshes, swamps, beaches, and other habitats due to sea-level rise at a scale that is relevant to regional decision making. (2) Extensive literature review and analysis of habitat, fish, and wildlife impacts potentially resulting from expected sea-level rise and other local climate changes. Synthesizing the available research is an important service for natural resource agencies that are only beginning to consider climate impacts on ecosystems and natural resources. (3) Analysis of government programs and policies relevant to coastal management and identification of opportunities to revise these policies in light of projected climate changes. An important aspect of this analysis is meeting with key decision makers at relevant state fish and wildlife agencies to better understand the factors that affect their abilities to effect policy changes. (4) Proactive campaign to share our results with diverse audiences. We have developed different research products, ranging from a technical report of the modeling results to short report briefs, to

  17. A shock-induced polymorph of anatase and rutile from the Chesapeake Bay impact structure, Virginia, U.S.A

    Science.gov (United States)

    Jackson, J.C.; Horton, J.W.; Chou, I.-Ming; Belkin, H.E.

    2006-01-01

    A shock-induced polymorph (TiO2II) of anatase and rutile has been identified in breccias from the late Eocene Chesapeake Bay impact structure. The breccia samples are from a recent, partially cored test hole in the central uplift at Cape Charles, Virginia. The drill cores from 744 to 823 m depth consist of suevitic crystalline-clast breccia and brecciated cataclastic gneiss in which the TiO2 phases anatase and rutile are common accessory minerals. Electron-microprobe imaging and laser Raman spectroscopy of TiO2 crystals, and powder X-ray diffraction (XRD) of mineral concentrates, confirm that a high-pressure, ??-PbO2 structured polymorph of TiO2 (TiO2II) coexists with anatase and rutile in matrix-hosted crystals and in inclusions within chlorite. Raman spectra of this polymorph include strong bands at wavenumbers (cm-1) 175, 281, 315, 342, 356, 425, 531, 571, and 604; they appear with anatase bands at 397, 515, and 634 cm-1, and rutile bands at 441 and 608 cm-1. XRD patterns reveal 12 lines from the polymorph that do not significantly interfere with those of anatase or rutile, and are consistent with the TiO2II that was first reported to occur naturally as a shock-induced phase in rutile from the Ries crater in Germany. The recognition here of a second natural shock-induced occurrence of TiO2II suggests that its presence in rocks that have not been subjected to ultrahigh-pressure regional metamorphism can be a diagnostic indicator for confirmation of suspected impact structures.

  18. Population ecology and shell chemistry of a phytal ostracode species (Loxoconcha matagordensis) in the Chesapeake Bay watershed

    Science.gov (United States)

    Vann, C.D.; Cronin, T. M.; Dwyer, G.S.

    2004-01-01

    Population ecology and shell chemistry were studied in the phytal ostracode Loxoconcha matagordensis (Swain 1955) collected from Zostera marina seagrass beds in the Chesapeake Bay to provide seasonal constraints on shell secretion time for paleothermometry. Population density and age structure were defined by two main breeding cycles that occurred between 01 to 15 June and 02 to 16 August 2001. The time interval between breeding cycles was ???2 months and total juvenile standing crop increased almost three-fold between the first and second breeding cycles. Dark brown over-wintered adults comprised the majority of the population between March and April 2001, while newly secreted translucent adults were predominant between June and September. Seasonal shell Mg/Ca and Sr/Ca ratios were positively correlated with water temperature at both sites, with the strongest correlations occurring between June and September from newly secreted shells at Dameron Marsh. Old, dark brown shells contained 10% to 23% and 1% to 6% less Mg/Ca and Sr/Ca, respectively, than new shells. Because a fossil assemblage of L. matagordensis will contain ???30% old shells (dark-brown), these results suggest that fossil Mg/Ca ratios yield an integrated late spring to summer temperature signal. Shell Mg/Ca and Sr/Ca ratios of specimens of L. matagordensis collected from living Zostera were positively correlated, suggesting that temperature may influence both elemental ratios. Mg/Ca and Sr/Ca ratios of fossil shells of the related species Loxoconcha sp. A obtained from four sediment cores were also studied and exhibited a weaker correlation between the two elemental ratios. ?? 2004 Elsevier B.V. All rights reserved.

  19. NASA-Modified Precipitation Products to Improve EPA Nonpoint Source Water Quality Modeling for the Chesapeake Bay

    Science.gov (United States)

    Nigro, Joseph; Toll, David; Partington, Ed; Ni-Meister, Wenge; Lee, Shihyan; Gutierrez-Magness, Angelica; Engman, Ted; Arsenault, Kristi

    2010-01-01

    The Environmental Protection Agency (EPA) has estimated that over 20,000 water bodies within the United States do not meet water quality standards. Ninety percent of the impairments are typically caused by nonpoint sources. One of the regulations in the Clean Water Act of 1972 requires States to monitor the Total Maximum Daily Load (TMDL), or the amount of pollution that can be carried by a water body before it is determined to be "polluted", for any watershed in the U.S.. In response to this mandate, the EPA developed Better Assessment Science Integrating Nonpoint Sources (BASINS) as a Decision Support Tool (DST) for assessing pollution and to guide the decision making process for improving water quality. One of the models in BASINS, the Hydrological Simulation Program -- Fortran (HSPF), computes daily stream flow rates and pollutant concentration at each basin outlet. By design, precipitation and other meteorological data from weather stations serve as standard model input. In practice, these stations may be unable to capture the spatial heterogeneity of precipitation events especially if they are few and far between. An attempt was made to resolve this issue by substituting station data with NASA modified/NOAA precipitation data. Using these data within HSPF, stream flow was calculated for seven watersheds in the Chesapeake Bay Basin during low flow periods, convective storm periods, and annual flows. In almost every case, the modeling performance of HSPF increased when using the NASA-modified precipitation data, resulting in better stream flow statistics and, ultimately, in improved water quality assessment.

  20. Rapid, storm-induced changes in the natural abundance of sup 15 N in a planktonic ecosystem, Chesapeake Bay, USA

    Energy Technology Data Exchange (ETDEWEB)

    Montoya, J.P.; McCarthy, J.J. (Harvard Univ., Cambridge, MA (United States)); Horrigan, S.G. (State Univ. of New York, Stony Brook (United States))

    1991-12-01

    Samples of dissolved inorganic nitrogen (DIN), particulate nitrogen (PN), and two species of zooplankton were collected during two north-south transects of the Chesapeake Bay in the autumn of 1984 (27-28 September and 3-5 October). During the first transect, the natural abundance of {sup 15}N ({delta} {sup 15}N) in the major dissolved and planktonic pools of nitrogen suggested that the {delta}{sup 15}N of PN was largely determined by isotopic fractionation during uptake of NH{sub 4}{sup +} by phytoplankton. Averaged over the transect as a whole, the {delta}{sup 15}N of the herbivorous calanoid copepod Acartia tonsa was 4.1% higher than that of the PN, while the {delta}{sup 15}N of the carnivorous ctenophore Mnemiopsis leidyi was 6.4% higher than that of the PN. In the interval between the two transects, storm-induced mixing of the water column resulted in the injection of NH{sub 4}{sup +} into the surface layer of the bay. In combination with ancillary physical, chemical, and biological data, these changes in {delta}{sup 15}N provided estimates of the isotopic fractionation factor for NH{sub 4}{sup +} uptake by phytoplankton ({alpha} = 1.0065-1.0080) as well as the turnover time of nitrogen in Acartia tonsa (6.0-9.6 days). Despite the changes in {delta}{sup 15}N observed during this cruise, the relative distribution of {sup 15}N between trophic levels was preserved: during the second transect, the difference in {delta}{sup 15}N between Acartia tonsa and PN was 3.6%, and the difference in {delta}{sup 15}N between Mnemiopsis leidyi and PN was 7.3%. These results demonstrate that the natural abundance of {sup 15}N can change dramatically on a time scale of days, and that time-series studies of the natural abundance of {sup 15}N can be a useful complement to studies using tracer additions of {sup 15}N to document nitrogen transformations in planktonic ecosystems.

  1. An individual-based modeling approach to spawning-potential per-recruit models: An application to blue crab (Callinectes sapidus) in Chesapeake Bay

    Science.gov (United States)

    Bunnell, D.B.; Miller, T.J.

    2005-01-01

    An individual-based modeling approach to estimate biological reference points for blue crabs (Callinectes sapidus) in Chesapeake Bay offered several advantages over conventional models: (i) known individual variation in size and growth rate could be incorporated, (ii) the underlying discontinuous growth pattern could be simulated, and (iii) the complexity of the fishery, where vulnerability is based on size, shell status (e.g., soft, hard), maturity, and sex could be accommodated. Across a range of natural mortality (M) scenarios (0.375-1.2??year-1), we determined the exploitation fraction (??) and fishing mortality (F) that protected 20% of the spawning potential of an unfished population, the current target. As M increased, ??20% and F-20% decreased. Assuming that M = 0.9??year-1, our models estimated ??20% = 0.45, which is greater than field-based estimates of ?? in 64% of the years since 1990. Hence, the commercial fishery has likely contributed to the recent population decline in Chesapeake Bay. Comparisons of our results with conventional per-recruit approaches indicated that incorporating the complexity of the fishery was the most important advantage in our individual-based modeling approach. ?? 2005 NRC.

  2. Assessing the effectiveness of winter cover crop on nitrate reduction in two-paired sub-basins on the Coastal Plain of the Chesapeake Bay Watershed

    Science.gov (United States)

    Lee, S.; Yeo, I. Y.; Sadeghi, A. M.; Mccarty, G.; Hively, W. D.; Lang, M. W.

    2014-12-01

    Best management practices (BMPs) have been widely adopted to improve water quality throughout the Chesapeake Bay Watershed (CBW). Winter cover crops (WCC) use has been highlighted for the reduction of nitrate leaching over the fallow season. Although various WCC practices are currently conducted in local croplands, the water quality improvement benefits of WCC have not been studied thoroughly at the watershed scale. The objective of this study is to assess the long-term impacts of WCC on reducing nitrate loadings using a processed-based watershed model, Soil and Water Assessment Tool (SWAT). Remote sensing based estimates of WCC biomass will be used to calibrate plant growth processes of SWAT and its nutrient cycling. The study will be undertaken in two-paired agricultural watersheds in the Coastal Plain of CBW. Multiple WCC practice scenarios will be prepared to investigate how nitrate loading varies with crop species, planting dates, and implementation areas. The performance of WCC on two-paired watersheds will be compared in order to understand the effects of different watershed characteristics on nitrate uptake by crops. The results will demonstrate the nitrate reduction efficiency of different WCC practices and identify the targeting area for WCC implementation at the watershed scale. This study will not only integrate remote sensing data into the physically based model but also extend our understandings of WCC functions. This will provide key information for effective conservation decision making. Key words: Water quality, Chesapeake Bay Watershed, Winter Cover Crop, Soil and Water Assessment Tool (SWAT)

  3. Polar organic compounds in pore waters of the Chesapeake Bay impact structure, Eyreville core hole: Character of the dissolved organic carbon and comparison with drilling fluids

    Science.gov (United States)

    Rostad, C.E.; Sanford, W.E.

    2009-01-01

    Pore waters from the Chesapeake Bay impact structure cores recovered at Eyreville Farm, Northampton County, Virginia, were analyzed to characterize the dissolved organic carbon. After squeezing or centrifuging, a small volume of pore water, 100 ??L, was taken for analysis by electrospray ionization-mass spectrometry. Porewater samples were analyzed directly without filtration or fractionation, in positive and negative mode, for polar organic compounds. Spectra in both modes were dominated by low-molecular-weight ions. Negative mode had clusters of ions differing by -60 daltons, possibly due to increasing concentrations of inorganic salts. The numberaverage molecular weight and weight-average molecular weight values for the pore waters from the Chesapeake Bay impact structure are higher than those reported for other aquatic sources of natural dissolved organic carbon as determined by electrospray ionization-mass spectrometry. In order to address the question of whether drilling mud fluids may have contaminated the pore waters during sample collection, spectra from the pore waters were compared to spectra from drilling mud fluids. Ions indicative of drilling mud fluids were not found in spectra from the pore waters, indicating there was no detectable contamination, and highlighting the usefulness of this analytical technique for detecting potential contamination during sample collection. ?? 2009 The Geological Society of America.

  4. Nutrient and physical profile data from four Microbial Exchanges and Coupling in Coastal Atlantic Systems (MECCAS) cruises collected aboard the R/V Gyre at the mouth of the Chesapeake Bay and northern Atlantic Ocean from February 17, 1985 to September 7, 1986 (NODC Accession 8800324)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Microbial Exchanges and Coupling in Coastal Atlantic Systems (MECCAS) cruise data collected aboard the R/V Gyre at the mouth of the Chesapeake Bay and northern...

  5. The Effects of Changes in Land Cover/Land Use on Nutrient Loadings to the Chesapeake Bay Estuary Using Forecasts of Future Urbanization

    Science.gov (United States)

    Prince, S.; Roberts, A. D.

    2006-12-01

    The effects of short-term and projected long-term changes in spatially explicit land cover/land use (LC/LU) on nutrient loadings (total nitrogen (TN) and total phosphorus (TP) in kg/ha/yr) were studied in the Chesapeake Bay watershed (164,000 km2) estuary. Version 3.0 of the USGS Chesapeake Bay's SPAtially Referenced Regressions on Watershed Attributes (SPARROW) model was implemented for the widely studied Patuxent River Basin in Maryland. Probabilities of LC change were estimated using projections of impervious surface locations at the LANDSAT (30m) scale and the Slope, Land use, Exclusion, Urban extent, Transportation, and Hillshade (SLEUTH) model for three development scenarios: current trends, smart growth, and ecologically sustainable to the Year 2030. Six Maryland Hydrologic Unit Code (HUC)-11 watersheds (three within and three outside of the basin) with verified (published) TN/TP nutrient loadings based on Year 2000 data from the Maryland Department of Natural Resources (DNR) were analyzed to see how they compared with the aggregated smaller catchments estimate of TN/TP that were contained within the larger boundaries of the HUC-11 watersheds and based on Year 2000 LC/LC and imperviousness data. The aggregated SPARROW TN always overpredicted the published values, whereas the SPARROW TP underpredicted the published DNR TP in three watersheds and overpredicted the DNR in the others. TN R2 = 0.90, whereas TP R2 = 0.69 in comparing DNR with SPARROW. Since the regression results just reported are only potential nutrient loadings for catchments independent of any other processes based on the model TN/TP general equations, when allowed to run in the true nonlinear structure of the SPARROW models that account for stream/catchment connectivity and water/land chemistry, even better nutrient estimates should able to be purported over larger watersheds throughout the Chesapeake Bay. In addition, TN/TP loadings from 85 of the smaller SPARROW reach catchments associated

  6. The effects of the Chesapeake Bay impact crater on the geologic framework and the correlation of hydrogeologic units of southeastern Virginia, south of the James River

    Science.gov (United States)

    Powars, David S.

    2000-01-01

    About 35 million years ago, a large comet or meteor slammed into the shallow shelf on the western margin of the Atlantic Ocean, creating the Chesapeake Bay impact crater. This report, the second in a series, refines the geologic framework of southeastern Virginia, south of the James River in and near the impact crater, and presents evidence for the existence of a pre-impact James River structural zone. The report includes detailed correlations of core lithologies with borehole geophysical logs; the correlations provide the foundation for the compilation of stratigraphic cross sections. These cross sections are tied into the geologic framework of the lower York-James Peninsula as presented in the first report in the series, Professional Paper 1612

  7. Application of geologic map information to water quality issues in the southern part of the Chesapeake Bay watershed, Maryland and Virginia, eastern United States

    Science.gov (United States)

    McCartan, L.; Peper, J.D.; Bachman, L.J.; Horton, J.W.

    1999-01-01

    Geologic map units contain much information about the mineralogy, chemistry, and physical attributes of the rocks mapped. This paper presents information from regional-scale geologic maps in Maryland and Virginia, which are in the southern part of the Chesapeake Bay watershed in the eastern United States. The geologic map information is discussed and analyzed in relation to water chemistry data from shallow wells and stream reaches in the area. Two environmental problems in the Chesapeake Bay watershed are used as test examples. The problems, high acidity and high nitrate concentrations in streams and rivers, tend to be mitigated by some rock and sediment types and not by others. Carbonate rocks (limestone, dolomite, and carbonate-cemented rocks) have the greatest capacity to neutralize acidic ground water and surface water in contact with them. Rocks and sediments having high carbon or sulfur contents (such as peat and black shale) potentially contribute the most toward denitrification of ground water and surface water in contact with them. Rocks and sediments that are composed mostly of quartz, feldspar, and light-colored clay (rocks such as granite and sandstone, sediments such as sand and gravel) tend not to alter the chemistry of waters that are in contact with them. The testing of relationships between regionally mapped geologic units and water chemistry is in a preliminary stage, and initial results are encouraging.Geologic map units contain much information about the mineralogy, chemistry, and physical attributes of the rocks mapped. This paper presents information from regional-scale geologic maps in Maryland and Virginia, which are in the southern part of the Chesapeake Bay watershed in the eastern United States. The geologic map information is discussed and analyzed in relation to water chemistry data from shallow wells and stream reaches in the area. Two environmental problems in the Chesapeake Bay watershed are used as test examples. The problems, high

  8. Declining nitrate-N yields in the Upper Potomac River Basin: What is really driving progress under the Chesapeake Bay restoration?

    Science.gov (United States)

    Eshleman, Keith N.; Sabo, Robert D.

    2016-12-01

    Reducing nutrient pollution of surface and coastal waters in the U.S. and elsewhere remains a major environmental and engineering challenge for the 21st century. In the case of the Chesapeake Bay restoration, we still lack scientific proof that watershed-based management actions have been effective at reducing nonpoint-source nutrient loads from the land to this estuary in accordance with restoration goals. While the conventional wisdom is that implementation of best management practices (BMP's) and wastewater treatment have turned the tide against nutrient pollution, we examined long-term (1986-present) nitrate-N trends in streams and major tributaries of the Upper Potomac River Basin (UPRB) and found that: 1) dramatic reductions in annual discharge-weighted mean nitrate-N concentrations and yields across the UPRB can be almost universally attributed to reductions in atmospheric N deposition as opposed to on-the-ground management actions such as implementation of BMP's; 2) observed water quality changes generally comport with a modified kinetic N saturation model (MKNSM); 3) the MKNSM can separate the nitrate-N yield that is responsive to atmospheric deposition from a "non-responsive" yield; and 4) N saturation from atmospheric N deposition appears to be an inherently reversible process across most of the landscape. These unanticipated region-wide water quality benefits can be attributed to NOx emission controls brought about by the 1990 Clean Air Act Amendments (and subsequent U.S. NOX control programs) and reflect a water quality "success story" in the Chesapeake Bay restoration.

  9. Confirmation of a meteoritic component in impact-melt rocks of the Chesapeake Bay impact structure, Virginia, USA - Evidence from osmium isotopic and PGE systematics

    Science.gov (United States)

    Lee, Seung Ryeol; Horton, J. Wright; Walker, Richard J.

    2006-06-01

    The osmium isotope ratios and platinum-group element (PGE) concentrations of impact-melt rocks in the Chesapeake Bay impact structure were determined. The impact-melt rocks come from the cored part of a lower-crater section of suevitic crystalline-clast breccia in an 823 m scientific test hole over the central uplift at Cape Charles, Virginia. The 187Os/188Os ratios of impact-melt rocks range from 0.151 to 0.518. The rhenium and platinum-group element (PGE) concentrations of these rocks are 30-270× higher than concentrations in basement gneiss, and together with the osmium isotopes indicate a substantial meteoritic component in some impact-melt rocks. Because the PGE abundances in the impact-melt rocks are dominated by the target materials, interelemental ratios of the impact-melt rocks are highly variable and nonchondritic. The chemical nature of the projectile for the Chesapeake Bay impact structure cannot be constrained at this time. Model mixing calculations between chondritic and crustal components suggest that most impact-melt rocks include a bulk meteoritic component of 0.01-0.1% by mass. Several impact-melt rocks with lowest initial 187Os/188Os ratios and the highest osmium concentrations could have been produced by additions of 0.1%-0.2% of a meteoritic component. In these samples, as much as 70% of the total Os may be of meteoritic origin. At the calculated proportions of a meteoritic component (0.01-0.1% by mass), no mixtures of the investigated target rocks and sediments can reproduce the observed PGE abundances of the impact-melt rocks, suggesting that other PGE enrichment processes operated along with the meteoritic contamination. Possible explanations are 1) participation of unsampled target materials with high PGE abundances in the impact-melt rocks, and 2) variable fractionations of PGE during syn- to post-impact events.

  10. Osmium-isotope Evidence for a Projectile Component in Impact-melt Rocks, Chesapeake Bay Impact Structure, Virginia, USA

    Science.gov (United States)

    Lee, S.; Horton, J. W.; Walker, R. J.

    2004-12-01

    The late Eocene Chesapeake Bay impact structure (CBIS) is preserved beneath post-impact sediments on the Atlantic margin of Virginia. This 85-km-diameter complex crater formed on the continental shelf of a passive margin in a layered target consisting of ocean water, Cretaceous and Tertiary sediments (mainly siliciclastic), and crystalline basement rocks. The basement rocks include Neoproterozoic granitoids and felsite as well as gneiss of undetermined age. In May, 2004, the USGS drilled an 823-m test hole in the central uplift of the CBIS at Cape Charles, Va., providing drill cuttings and limited core. The core from 744 to 823 m depth contains crystalline-clast breccia and brecciated gneiss that are distinct from sediment-clast breccias recovered from coreholes in the annular trough of the CBIS. Rocks interpreted to be impact-melt clasts and dikes in the crystalline-clast breccia were sampled for analyses of osmium (Os) concentrations and 187Os/188Os ratios to test for evidence of the projectile. These analyses were conducted on samples from a dike (aphanitic to partly hyaline, ST2440.8C) within a gneissic block, from a block of holocrystalline mafic rock (aphanitic, ST2453.3C), and from a flow-laminated bomb (aphanitic to partly hyaline, ST2570.0C). The Os concentrations and 187Os/188Os ratios for samples ST2440.8C, ST2453.3C and ST2570.0C are 0.928, 0.711 and 0.312 ppb, and 0.15205, 0.15545 and 0.22345, respectively. These values are much higher (Os) or lower (187Os/188Os) than those reported for rocks of the upper continental crust, suggesting a significant contribution of osmium from the projectile in these impact-melt rocks. Moreover, a strong negative correlation between 187Os/188Os and Os for these samples suggests that it may be possible to use mixing curves to calculate the proportions of projectile and target-rock components. Our results from the CBIS contrast with those from the Chicxulub crater, where there is little or no evidence for the

  11. California Least Tern breeding survey south San Francisco Bay

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report documents the field work conducted by members -of the South Bay Institute for Avian Studies during 1981. The primary purpose of this study was to survey...

  12. A rapid procedure for the determination of thorium, uranium, cadmium and molybdenum in small sediment samples by inductively coupled plasma-mass spectrometry: Application in Chesapeake Bay

    Science.gov (United States)

    Zheng, Yen; Weinman, B.; Cronin, T.; Fleisher, M.Q.; Anderson, Robert F.

    2003-01-01

    This paper describes a rapid procedure that allows precise analysis of Mo, Cd, U and Th in sediment samples as small as 10 mg by using a novel approach that utilizes a "pseudo" isotope dilution for Th and conventional isotope dilution for Mo, Cd and U by ICP-MS. Long-term reproducibility of the method is between 2.5 and 5% with an advantage of rapid analysis on a single digestion of sediment sample and the potential of adding other elements of interest if so desired. Application of this method to two piston cores collected near the mouth of the Patuxent River in Chesapeake Bay showed that the accumulation of authigenic Mo and Cd varied in response to the changing bottom water redox conditions, with anoxia showing consistent oscillations throughout both pre-industrial and industrial times. Accumulation of authigenic U shows consistent oscillations as well, without any apparent increase in productivity related to anoxic trends. Degrees of Mo and Cd enrichment also inversely correlate to halophilic microfaunal assemblages already established as paleoclimate proxies within the bay indicating that bottom water anoxia is driven in part by the amount of freshwater discharge that the area receives. ?? 2002 Elsevier Science Ltd. All rights reserved.

  13. Is sea level rise accelerating in the Chesapeake Bay? A demonstration of a novel new approach for analyzing sea level data

    Science.gov (United States)

    Ezer, Tal; Corlett, William Bryce

    2012-10-01

    Sea level data from the Chesapeake Bay are used to test a novel new analysis method for studies of sea level rise (SLR). The method, based on Empirical Mode Decomposition and Hilbert-Huang Transformation, separates the sea level trend from other oscillating modes and reveals how the mean sea level changes over time. Bootstrap calculations test the robustness of the method and provide confidence levels. The analysis shows that rates of SLR have increased from ˜1-3 mm y-1 in the 1930s to ˜4-10 mm y-1 in 2011, an acceleration of ˜0.05-0.10 mm y-2 that is larger than most previous studies, but comparable to recent findings by Sallenger and collaborators. While land subsidence increases SLR rates in the bay relative to global SLR, the acceleration results support Sallenger et al.'s proposition that an additional contribution to SLR from climatic changes in ocean circulation is affecting the region.

  14. Non-O1/Non-O139 Vibrio cholerae Carrying Multiple Virulence Factors and V. cholerae O1 in the Chesapeake Bay, Maryland

    Science.gov (United States)

    Ceccarelli, Daniela; Chen, Arlene; Hasan, Nur A.; Rashed, Shah M.; Huq, Anwar

    2015-01-01

    Non-O1/non-O139 Vibrio cholerae inhabits estuarine and coastal waters globally, but its clinical significance has not been sufficiently investigated, despite the fact that it has been associated with septicemia and gastroenteritis. The emergence of virulent non-O1/non-O139 V. cholerae is consistent with the recognition of new pathogenic variants worldwide. Oyster, sediment, and water samples were collected during a vibrio surveillance program carried out from 2009 to 2012 in the Chesapeake Bay, Maryland. V. cholerae O1 was detected by a direct fluorescent-antibody (DFA) assay but was not successfully cultured, whereas 395 isolates of non-O1/non-O139 V. cholerae were confirmed by multiplex PCR and serology. Only a few of the non-O1/non-O139 V. cholerae isolates were resistant to ampicillin and/or penicillin. Most of the isolates were sensitive to all antibiotics tested, and 77 to 90% carried the El Tor variant hemolysin gene hlyAET, the actin cross-linking repeats in toxin gene rtxA, the hemagglutinin protease gene hap, and the type 6 secretion system. About 19 to 21% of the isolates carried the neuraminidase-encoding gene nanH and/or the heat-stable toxin (NAG-ST), and only 5% contained a type 3 secretion system. None of the non-O1/non-O139 V. cholerae isolates contained Vibrio pathogenicity island-associated genes. However, ctxA, ace, or zot was present in nine isolates. Fifty-five different genotypes showed up to 12 virulence factors, independent of the source of isolation, and represent the first report of both antibiotic susceptibility and virulence associated with non-O1/non-O139 V. cholerae from the Chesapeake Bay. Since these results confirm the presence of potentially pathogenic non-O1/non-O139 V. cholerae, monitoring for total V. cholerae, regardless of serotype, should be done within the context of public health. PMID:25556194

  15. Non-O1/non-O139 Vibrio cholerae carrying multiple virulence factors and V. cholerae O1 in the Chesapeake Bay, Maryland.

    Science.gov (United States)

    Ceccarelli, Daniela; Chen, Arlene; Hasan, Nur A; Rashed, Shah M; Huq, Anwar; Colwell, Rita R

    2015-03-01

    Non-O1/non-O139 Vibrio cholerae inhabits estuarine and coastal waters globally, but its clinical significance has not been sufficiently investigated, despite the fact that it has been associated with septicemia and gastroenteritis. The emergence of virulent non-O1/non-O139 V. cholerae is consistent with the recognition of new pathogenic variants worldwide. Oyster, sediment, and water samples were collected during a vibrio surveillance program carried out from 2009 to 2012 in the Chesapeake Bay, Maryland. V. cholerae O1 was detected by a direct fluorescent-antibody (DFA) assay but was not successfully cultured, whereas 395 isolates of non-O1/non-O139 V. cholerae were confirmed by multiplex PCR and serology. Only a few of the non-O1/non-O139 V. cholerae isolates were resistant to ampicillin and/or penicillin. Most of the isolates were sensitive to all antibiotics tested, and 77 to 90% carried the El Tor variant hemolysin gene hlyAET, the actin cross-linking repeats in toxin gene rtxA, the hemagglutinin protease gene hap, and the type 6 secretion system. About 19 to 21% of the isolates carried the neuraminidase-encoding gene nanH and/or the heat-stable toxin (NAG-ST), and only 5% contained a type 3 secretion system. None of the non-O1/non-O139 V. cholerae isolates contained Vibrio pathogenicity island-associated genes. However, ctxA, ace, or zot was present in nine isolates. Fifty-five different genotypes showed up to 12 virulence factors, independent of the source of isolation, and represent the first report of both antibiotic susceptibility and virulence associated with non-O1/non-O139 V. cholerae from the Chesapeake Bay. Since these results confirm the presence of potentially pathogenic non-O1/non-O139 V. cholerae, monitoring for total V. cholerae, regardless of serotype, should be done within the context of public health. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. 33 CFR 165.511 - Security Zone; Atlantic Ocean, Chesapeake & Delaware Canal, Delaware Bay, Delaware River and its...

    Science.gov (United States)

    2010-07-01

    ... escorted passenger vessels in the Captain of the Port, Delaware Bay zone as defined in 33 CFR 3.25-05. (b... vessel in order to ensure safe passage in accordance with the Navigation Rules as seen in 33 CFR...

  17. A chemostratigraphic method to determine the end of impact-related sedimentation at marine-target impact craters (Chesapeake Bay, Lockne, Tvären)

    Science.gov (United States)

    Ormö, Jens; Hill, Andrew C.; Self-Trail, Jean M.

    2010-01-01

    To better understand the impact cratering process and its environmental consequences at the local to global scale, it is important to know when in the geological record of an impact crater the impact-related processes cease. In many instances, this occurs with the end of early crater modification, leaving an obvious sedimentological boundary between impactites and secular sediments. However, in marine-target craters the transition from early crater collapse (i.e., water resurge) to postimpact sedimentation can appear gradual. With the a priori assumption that the reworked target materials of the resurge deposits have a different chemical composition to the secular sediments we use chemostratigraphy (δ13Ccarb, %Corg, major elements) of sediments from the Chesapeake Bay, Lockne, and Tvären craters, to define this boundary. We show that the end of impact-related sedimentation in these cases is fairly rapid, and does not necessarily coincide with a visual boundary (e.g., grain size shift). Therefore, in some cases, the boundary is more precisely determined by chemostratigraphy, especially carbonate carbon isotope variations, rather than by visual inspection. It is also shown how chemostratigraphy can confirm the age of marine-target craters that were previously determined by biostratigraphy; by comparing postimpact carbon isotope trends with established regional trends.

  18. Pore-water chemistry from the ICDP-USGS coer hole in the Chesapeake Bay impact structure--Implications for paleohydrology, microbial habitat, and water resources

    Science.gov (United States)

    Sanford, Ward E.; Voytek, Mary A.; Powars, David S.; Jones, Blair F.; Cozzarelli, Isabelle M.; Eganhouse, Robert P.; Cockell, Charles S.

    2009-01-01

    We investigated the groundwater system of the Chesapeake Bay impact structure by analyzing the pore-water chemistry in cores taken from a 1766-m-deep drill hole 10 km north of Cape Charles, Virginia. Pore water was extracted using high-speed centrifuges from over 100 cores sampled from a 1300 m section of the drill hole. The pore-water samples were analyzed for major cations and anions, stable isotopes of water and sulfate, dissolved and total carbon, and bioavailable iron. The results reveal a broad transition between fresh and saline water from 100 to 500 m depth in the post-impact sediment section, and an underlying syn-impact section that is almost entirely filled with brine. The presence of brine in the lowermost post-impact section and the trend in the dissolved chloride with depth suggest a transport process dominated by molecular diffusion and slow, compaction-driven, upward flow. Major ion results indicate residual effects of diagenesis from heating, and a pre-impact origin for the brine. High levels of dissolved organic carbon (6-95 mg/L) and the distribution of electron acceptors indicate an environment that may be favorable for microbial activity throughout the drilled section. The concentration and extent of the brine is much greater than had previously been observed, suggesting its occurrence may be common in the inner crater. However, groundwater flow conditions in the structure may reduce the salt-water-intrusion hazard associated with the brine.

  19. Pore-water chemistry from the ICDP-USGS core hole in the Chesapeake Bay impact structure-Implications for paleohydrology, microbial habitat, and water resources

    Science.gov (United States)

    Sanford, W.E.; Voytek, M.A.; Powars, D.S.; Jones, B.F.; Cozzarelli, I.M.; Cockell, C.S.; Eganhouse, R.P.

    2009-01-01

    We investigated the groundwater system of the Chesapeake Bay impact structure by analyzing the pore-water chemistry in cores taken from a 1766-m-deep drill hole 10 km north of Cape Charles, Virginia. Pore water was extracted using high-speed centrifuges from over 100 cores sampled from a 1300 m section of the drill hole. The pore-water samples were analyzed for major cations and anions, stable isotopes of water and sulfate, dissolved and total carbon, and bioavailable iron. The results reveal a broad transition between freshwater and saline water from 100 to 500 m depth in the postimpact sediment section, and an underlying synimpact section that is almost entirely filled with brine. The presence of brine in the lowermost postimpact section and the trend in dissolved chloride with depth suggest a transport process dominated by molecular diffusion and slow, compaction-driven, upward flow. Major ion results indicate residual effects of diagenesis from heating, and a pre-impact origin for the brine. High levels of dissolved organic carbon (6-95 mg/L) and the distribution of electron acceptors indicate an environment that may be favorable for microbial activity throughout the drilled section. The concentration and extent of the brine is much greater than had previously been observed, suggesting that its occurrence may be common in the inner crater. However, groundwater-flow conditions in the structure may reduce the saltwater-intrusion hazard associated with the brine. ?? 2009 The Geological Society of America.

  20. The distribution of phosphorus in Popes Creek, VA, and in the Pocomoke River, MD: Two watersheds with different land management practices in the Chesapeake Bay Basin

    Science.gov (United States)

    Simon, N.S.; Bricker, O.P.; Newell, W.; McCoy, J.; Morawe, R.

    2005-01-01

    This paper compares phosphorus (P) concentrations in sediments from two watersheds, one with, and one without, intensive animal agriculture. The watersheds are in the coastal plain of the Chesapeake Bay and have similar physiographic characteristics. Agriculture in the Pocomoke River, MD, watershed supplied 2.7 percent of all broiler chickens produced in the USA in 1997. Poultry litter is an abundant, local source of manure for crops. Broiler chickens are not produced in the Popes Creek, VA, watershed and poultry manure is, therefore, not a major source of fertilizer. The largest concentrations of P in sediment samples are found in floodplain and main-stem bottom sediment in both watersheds. Concentrations of total P and P extracted with 1N HCl are significantly larger in main-stem bottom sediments from the Pocomoke River than in main-stem bottom sediments from Popes Creek. Larger concentrations of P are associated with what are potentially redox sensitive iron oxyhydroxides in sediment samples from the Pocomoke River watershed than are associated with what are potentially redox sensitive iron oxyhydroxides in sediment samples from the Popes Creek watershed. Data for P and iron (Fe) concentrations in sediments from the Popes Creek watershed provide a numerical framework (baseline) with which to compare P and Fe concentrations in sediment from the Pocomoke River watershed. ?? Springer 2005.

  1. Diffusive exchange of polycyclic aromatic hydrocarbons across the air-water interface of the Patapsco River, an urbanized subestuary of the Chesapeake Bay

    Energy Technology Data Exchange (ETDEWEB)

    Bamford, H.A.; Offenberg, J.H.; Larsen, R.K.; Ko, F.C.; Baker, J.E. [Univ. of Maryland, Solomons, MD (United States)

    1999-07-01

    Air-water exchange fluxes of 13 polycyclic aromatic hydrocarbons (PAHs) were determined along a transect in the Patapsco River from the Inner Harbor of Baltimore, MD, to the mainstem of the northern Chesapeake Bay. Sampling took place at six sites during three sampling intensives (June 1996, February 1997, and July 1997) and at one site every ninth day between March 1997 and March 1998 to measure spatial, daily, and annual variability in the fluxes. The direction and magnitude of the daily fluxes of individual PAHs were strongly influenced by the wind speed and direction, by the air temperature, and by the highly variable PAH concentrations in the gas and dissolved phases. Individual fluxes ranged from 14,200 ng m{sup {minus}2} day{sup {minus}1} net volatilization of fluorene during high winds to 11,400 ng m{sup {minus}2} day{sup {minus}1} net absorption of phenanthrene when prevailing winds blowing from the northwest across the city of Baltimore elevated gaseous PAH concentrations over the water. The largest PAH volatilization fluxes occurred adjacent to the stormwater discharges, driven by elevated dissolved PAH concentrations in surface waters. Estimated annual volatilization fluxes ranged from 1.1 {micro}g m{sup {minus}2} yr{sup {minus}1} for chrysene to 800 {micro}g m{sup {minus}2} yr{sup {minus}1} for fluorene.

  2. Survey of Nesting Osprey at Back Bay National Wildlife Refuge and False Cape State Park

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A survey of nesting Osprey (Pandion Haliaetus) was conducted during the nesting season of 1990. The survey was conducted in the bay waters of Back Bay National...

  3. Survey of Nesting Osprey at Back Bay National Wildlife Refuge and False Cape State Park

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A survey of nesting Osprey (Pandion Haliaetus) was conducted during the nesting season of 1989. The survey was conducted in the bay waters of Back Bay National...

  4. The Chesapeake: A Boating Guide to Weather. Educational Series Number 25.

    Science.gov (United States)

    Lucy, Jon; And Others

    The purpose of this publication is to promote a better understanding of how basic weather features develop on Chesapeake Bay and enable boaters to enjoy the Bay's unique waterways. Sections include: (1) Chesapeake Bay climate; (2) general weather features; (3) seasonal trends; (4) sources of weather information and forecasts; (5) weather service…

  5. 77 FR 2317 - Captain John Smith Chesapeake National Historic Trail Advisory Council

    Science.gov (United States)

    2012-01-17

    ... National Park Service Captain John Smith Chesapeake National Historic Trail Advisory Council AGENCY... Captain John Smith Chesapeake National Historic Trail will hold a meeting via conference call. Designated... voyages of Captain John Smith to chart the land and waterways of the Chesapeake Bay. This meeting...

  6. Trends in nutrients and suspended solids at the Fall Line of five tributaries to the Chesapeake Bay in Virginia, July 1988 through June 1995

    Science.gov (United States)

    Bell, C.F.; Belval, D.L.; Campbell, J.P.

    1996-01-01

    Water-quality samples were collected at the Fall Line of five tributaries to the Chesapeake Bay in Virginia during a 6- to 7-year period. The water-quality data were used to estimate loads of nutrients and suspended solids from these tributaries to the non-tidal part of Chesapeake Bay Basin and to identify trends in water quality. Knowledge of trends in water quality is required to assess the effectiveness of nutrient manage- ment strategies in the five basins. Multivariate log-linear regression and the seasonal Kendall test were used to estimate flow-adjusted trends in constituent concentration and load. Results of multivariate log-linear regression indicated a greater number of statistically significant trends than the seasonal Kendall test; how-ever, when both methods indicated a significant trend, both agreed on the direction of the trend. Interpre- tation of the trend estimates for this report was based on results of the parametric regression method. No significant trends in total nitrogen concentration were detected at the James River monitoring station from July 1988 through June 1995, though total Kjeldahl nitrogen concen- tration decreased slightly in base-flow samples. Total phosphorus concentration decreased about 29 percent at this station during the sampling period. Most of the decrease can be attributed to reductions in point-source phosphorus loads in 1988 and 1989, especially the phosphate detergent ban of 1988. No significant trends in total suspended solids were observed at the James River monitoring station, and no trends in runoff- derived constituents were interpreted for this river. Significant decreases were detected in concentrations of total nitrogen, total Kjeldahl nitrogen, dissolved nitrite-plus-nitrate nitrogen, and total suspended solids at the Rappahannock River monitoring station between July 1988 and June 1995. A similar downward trend in total phosphorus concentration was significant at the 90-percent confidence level, but not the

  7. Ground-water discharge and base-flow nitrate loads of nontidal streams, and their relation to a hydrogeomorphic classification of the Chesapeake Bay Watershed, middle Atlantic Coast

    Science.gov (United States)

    Bachman, L. Joseph; Lindsey, Bruce D.; Brakebill, John W.; Powars, David S.

    1998-01-01

    Existing data on base-flow and groundwater nitrate loads were compiled and analyzed to assess the significance of groundwater discharge as a source of the nitrate load to nontidal streams of the Chesapeake Bay watershed. These estimates were then related to hydrogeomorphic settings based on lithology and physiographic province to provide insight on the areal distribution of ground-water discharge. Base-flow nitrate load accounted for 26 to about 100 percent of total-flow nitrate load, with a median value of 56 percent, and it accounted for 17 to 80 percent of total-flow total-nitrogen load, with a median value of 48 percent. Hydrograph separations were conducted on continuous streamflow records from 276 gaging stations within the watershed. The values for base flow thus calculated were considered an estimate of ground-water discharge. The ratio of base flow to total flow provided an estimate of the relative importance of ground-water discharge within a basin. Base-flow nitrate loads, total-flow nitrate loads, and total-flow total-nitrogen loads were previously computed from water-quality and discharge measurements by use of a regression model. Base-flow nitrate loads were available from 78 stations, total-flow nitrate loads were available from 86 stations, and total-flow total-nitrogen loads were available for 48 stations. The percentage of base-flow nitrate load to total-flow nitrate load could be computed for 57 stations, whereas the percentage of base-flow nitrate load to totalflow total-nitrogen load could be computed for 36 stations. These loads were divided by the basin area to obtain yields, which were used to compare the nitrate discharge from basins of different sizes. The results indicate that ground-water discharge is a significant source of water and nitrate to the total streamflow and nitrate load. Base flow accounted for 16 to 92 percent of total streamflow at the 276 sampling sites, with a median value of 54 percent. It is estimated that of the 50

  8. Comparison of clast frequency and size in the resurge deposits at the Chesapeake Bay impact structure (Eyreville A and Langley cores): Clues to the resurge process

    Science.gov (United States)

    Ormo, J.; Sturkell, E.; Horton, J.W.; Powars, D.S.; Edwards, L.E.

    2009-01-01

    Collapse and inward slumping of unconsolidated sedimentary strata expanded the Chesapeake Bay impact structure far beyond its central basement crater. During crater collapse, sediment-loaded water surged back to fill the crater. Here, we analyze clast frequency and granulometry of these resurge deposits in one core hole from the outermost part of the collapsed zone (i.e., Langley) as well as a core hole from the moat of the basement crater (i.e., Eyreville A). Comparisons of clast provenance and flow dynamics show that at both locations, there is a clear change in clast frequency and size between a lower unit, which we interpret to be dominated by slumped material, and an upper, water-transported unit, i.e., resurge deposit. The contribution of material to the resurge deposit was primarily controlled by stripping and erosion. This includes entrainment of fallback ejecta and sediments eroded from the surrounding seafloor, found to be dominant at Langley, and slumped material that covered the annular trough and basement crater, found to be dominant at Eyreville. Eyreville shows a higher content of crystalline clasts than Langley. There is equivocal evidence for an anti-resurge from a collapsing central water plume or, alternatively, a second resurge pulse, as well as a transition into oscillating resurge. The resurge material shows more of a debris-flow-like transport compared to resurge deposits at some other marine target craters, where the ratio of sediment to water has been relatively low. This result is likely a consequence of the combination of easily disaggregated host sediments and a relatively shallow target water depth. ?? 2009 The Geological Society of America.

  9. Investigation of vegetation-induced drag parameterizations for natural and nature-based extreme events coastal protection in the Chesapeake Bay

    Science.gov (United States)

    Maldonado, S.; Suckale, J.; Ferreira, C.; Arkema, K.

    2016-12-01

    Increasing intensity and frequency of extreme meteorological events around the world highlight the need for resilient coastal defenses. For more than a century, it has been recognized that coastal ecosystems such as marshes and mangroves may mitigate the damage caused by natural hazards such as storms. Aquatic vegetation can potentially attenuate waves and currents through drag forces, with strong implications for sediment transport processes and hence morphological evolution. However, although observations exist that support such a theory, an accurate quantification of the protective role of coastal ecosystems remains a standing challenge for the scientific community, which manifests itself in the large, diverse set of available empirical expressions for parameterizing the fluid-vegetation interaction. We propose a comparison of different state-of-the-art parameterizations for the effect of vegetation on hydrodynamics (particularly, the drag coefficient), with varying degrees of complexity and number of required input variables. The inter-comparison of such alternatives, when validated against field data, can lead to a modeling framework that optimizes the trade-offs between complexity, input requirements and uncertainty in the results. We focus our numerical study on storm events in the marshes and wetlands of Chesapeake Bay. We simulate the hydrodynamics via the Non-Linear Shallow Water Equations, which are in turn solved numerically through a Finite Volume scheme. The simulations are complemented by an ongoing 2-years field campaign, where we continuously collect hydrodynamic measurements such as free surface elevation and vertical velocity profiles, biophysical characteristics of the vegetation and high-resolution topo-bathymetric data of the site. Field measurements are used for calibration and validation purposes. We also investigate some implications on sediment transport processes. We expect that results from our study can support policy makers and

  10. Myxosporean plasmodial infection associated with ulcerative lesions in young-of-the-year Atlantic menhaden in a tributary of the Chesapeake Bay, and possible links to Kudoa clupeidae

    Science.gov (United States)

    Reimschuessel, R.; Gieseker, C.M.; Driscoll, C.; Baya, A.; Kane, A.S.; Blazer, V.S.; Evans, J.J.; Kent, M.L.; Moran, J.D.W.; Poynton, S.L.

    2003-01-01

    Ulcers in Atlantic menhaden Brevoortia tyrannus (Latrobe) (Clupeidae), observed along the USA east coast, have been attributed to diverse etiologies including bacterial, fungal and, recently, harmful algal blooms. To understand the early pathogenesis of these lesions, we examined juvenile Atlantic menhaden collected during their seasonal presence in Chesapeake Bay tributaries from April to October 1999 and from March to August 2000. We conducted histopathological examinations of young-of-the-year fish from the Pocomoke River tributary, which has a history of fish mortalities and high lesion prevalence. Kudoa clupeidae (Myxozoa: Myxosporea) spores were present in the muscles of fish collected in both years. Of the fish assessed by histology in April, 5 to 14% were infected, while in May 90 to 96% were infected. Infection rates remained high during the summer. Mature spores were primarily located within myomeres and caused little or no observable pathological changes. Ultrastructure showed spores with capsulogenic cells bearing filamentous projections, and a basal crescentic nucleus with mottled nucleoplasm containing cleaved, condensed chromatin. Also, a highly invasive plasmodial stage of a myxozoan was found in the lesions of juvenile Atlantic menhaden. The plasmodia were observed in fish collected between May and July, with the maximum occurrence in late June 1999 and late May 2000. Plasmodia penetrated and surrounded muscle bundles, causing grossly observable raised lesions in 73% of all fish infected with this invasive stage. Plasmodia were also detected in the visceral organs, branchial arches, and interocular muscles of some fish. Some of the invasive extrasporogonic plasmodial lesions were associated with ulcers and chronic inflammatory infiltrates. The plasmodial stage appeared to slough out of the tissue with subsequent evidence of wound healing. Ultrastructure showed plasmodia with an elaborate irregular surface, divided into distinct ectoplasm and

  11. Geologic columns for the ICDP-USGS Eyreville A and C cores, Chesapeake Bay impact structure: Postimpact sediments, 444 to 0 m depth

    Science.gov (United States)

    Edwards, L.E.; Powars, D.S.; Browning, J.V.; McLaughlin, P.P.; Miller, K.G.; ,; Kulpecz, A.A.; Elbra, T.

    2009-01-01

    A 443.9-m-thick, virtually undisturbed section of postimpact deposits in the Chesapeake Bay impact structure was recovered in the Eyreville A and C cores, Northampton County, Virginia, within the "moat" of the structure's central crater. Recovered sediments are mainly fine-grained marine siliciclastics, with the exception of Pleistocene sand, clay, and gravel. The lowest postimpact unit is the upper Eocene Chickahominy Formation (443.9-350.1 m). At 93.8 m, this is the maximum thickness yet recovered for deposits that represent the return to "normal marine" sedimentation. The Drummonds Corner beds (informal) and the Old Church Formation are thin Oligocene units present between 350.1 and 344.7 m. Above the Oligocene, there is a more typical Virginia coastal plain succession. The Calvert Formation (344.7-225.4 m) includes a thin lower Miocene part overlain by a much thicker middle Miocene part. From 225.4 to 206.0 m, sediments of the middle Miocene Choptank Formation, rarely reported in the Virginia coastal plain, are present. The thick upper Miocene St. Marys and Eastover Formations (206.0-57.8 m) appear to represent a more complete succession than in the type localities. Correlation with the nearby Kiptopeke core indicates that two Pliocene units are present: Yorktown (57.8-32.2 m) and Chowan River Formations (32.2-18.3 m). Sediments at the top of the section represent an upper Pleistocene channel-fill and are assigned to the Butlers Bluff and Occohannock Members of the Nassawadox Formation (18.3-0.6 m). ?? 2009 The Geological Society of America.

  12. Geologic columns for the ICDP-USGS Eyreville A and B cores, Chesapeake Bay impact structure: Sediment-clast breccias, 1096 to 444 m depth

    Science.gov (United States)

    Edwards, L.E.; Powars, D.S.; Gohn, G.S.; Dypvik, H.

    2009-01-01

    The Eyreville A and B cores, recovered from the "moat" of the Chesapeake Bay impact structure, provide a thick section of sediment-clast breccias and minor stratified sediments from 1095.74 to 443.90 m. This paper discusses the components of these breccias, presents a geologic column and descriptive lithologic framework for them, and formalizes the Exmore Formation. From 1095.74 to ??867 m, the cores consist of nonmarine sediment boulders and sand (rare blocks up to 15.3 m intersected diameter). A sharp contact in both cores at ??867 m marks the lowest clayey, silty, glauconitic quartz sand that constitutes the base of the Exmore Formation and its lower diamicton member. Here, material derived from the upper sediment target layers, as well as some impact ejecta, occurs. The block-dominated member of the Exmore Formation, from ??855-618.23 m, consists of nonmarine sediment blocks and boulders (up to 45.5 m) that are juxtaposed complexly. Blocks of oxidized clay are an important component. Above 618.23 m, which is the base of the informal upper diamicton member of the Exmore Formation, the glauconitic matrix is a consistent component in diamicton layers between nonmarine sediment clasts that decrease in size upward in the section. Crystalline-rock clasts are not randomly distributed but rather form local concentrations. The upper part of the Exmore Formation consists of crudely fining-upward sandy packages capped by laminated silt and clay. The overlap interval of Eyreville A and B (940-??760 m) allows recognition of local similarities and differences in the breccias. ?? 2009 The Geological Society of America.

  13. Deficient plakophilin-1 expression due to a mutation in PKP1 causes ectodermal dysplasia-skin fragility syndrome in Chesapeake Bay retriever dogs.

    Directory of Open Access Journals (Sweden)

    Thierry Olivry

    Full Text Available In humans, congenital and hereditary skin diseases associated with epidermal cell-cell separation (acantholysis are very rare, and spontaneous animal models of these diseases are exceptional. Our objectives are to report a novel congenital acantholytic dermatosis that developed in Chesapeake Bay retriever dogs. Nine affected puppies in four different litters were born to eight closely related clinically normal dogs. The disease transmission was consistent with an autosomal recessive mode of inheritance. Clinical signs occurred immediately after birth with superficial epidermal layers sloughing upon pressure. At three month of age, dogs exhibited recurrent superficial skin sloughing and erosions at areas of friction and mucocutaneous junctions; their coat was also finer than normal and there were patches of partial hair loss. At birth, histopathology revealed severe suprabasal acantholysis, which became less severe with ageing. Electron microscopy demonstrated a reduced number of partially formed desmosomes with detached and aggregated keratin intermediate filaments. Immunostaining for desmosomal adhesion molecules revealed a complete lack of staining for plakophilin-1 and anomalies in the distribution of desmoplakin and keratins 10 and 14. Sequencing revealed a homozygous splice donor site mutation within the first intron of PKP1 resulting in a premature stop codon, thereby explaining the inability to detect plakophilin-1 in the skin. Altogether, the clinical and pathological findings, along with the PKP1 mutation, were consistent with the diagnosis of ectodermal dysplasia-skin fragility syndrome with plakophilin-1 deficiency. This is the first occurrence of ectodermal dysplasia-skin fragility syndrome in an animal species. Controlled mating of carrier dogs would yield puppies that could, in theory, be tested for gene therapy of this rare but severe skin disease of children.

  14. Rising sea level, temperature, and precipitation impact plant and ecosystem responses to elevated CO2 on a Chesapeake Bay wetland: review of a 28-year study.

    Science.gov (United States)

    Drake, Bert G

    2014-11-01

    An ongoing field study of the effects of elevated atmospheric CO2 on a brackish wetland on Chesapeake Bay, started in 1987, is unique as the longest continually running investigation of the effects of elevated CO2 on an ecosystem. Since the beginning of the study, atmospheric CO2 increased 18%, sea level rose 20 cm, and growing season temperature varied with approximately the same range as predicted for global warming in the 21st century. This review looks back at this study for clues about how the effects of rising sea level, temperature, and precipitation interact with high atmospheric CO2 to alter the physiology of C3 and C4 photosynthetic species, carbon assimilation, evapotranspiration, plant and ecosystem nitrogen, and distribution of plant communities in this brackish wetland. Rising sea level caused a shift to higher elevations in the Scirpus olneyi C3 populations on the wetland, displacing the Spartina patens C4 populations. Elevated CO2 stimulated carbon assimilation in the Scirpus C3 species measured by increased shoot and root density and biomass, net ecosystem production, dissolved organic and inorganic carbon, and methane production. But elevated CO2 also decreased biomass of the grass, S. patens C4. The elevated CO2 treatment reduced tissue nitrogen concentration in shoots, roots, and total canopy nitrogen, which was associated with reduced ecosystem respiration. Net ecosystem production was mediated by precipitation through soil salinity: high salinity reduced the CO2 effect on net ecosystem production, which was zero in years of severe drought. The elevated CO2 stimulation of shoot density in the Scirpus C3 species was sustained throughout the 28 years of the study. Results from this study suggest that rising CO2 can add substantial amounts of carbon to ecosystems through stimulation of carbon assimilation, increased root exudates to supply nitrogen fixation, reduced dark respiration, and improved water and nitrogen use efficiency.

  15. D00129: NOS Hydrographic Survey , Chesapeake Bay, Nautilus Shoal, Virginia, 1998-09-18

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  16. H06368: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1938-10-20

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  17. H06598: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1940-10-04

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  18. F00294: NOS Hydrographic Survey , Lower Chesapeake Bay, Virginia, 1987-03-03

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  19. F00300: NOS Hydrographic Survey , Lower Chesapeake Bay, Virginia, 1987-07-09

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  20. F00255: NOS Hydrographic Survey , Southern Chesapeake Bay, Virginia, 1984-05-23

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  1. H11402: NOS Hydrographic Survey , Approaches to Chesapeake Bay, Virginia, 2005-10-27

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  2. H11016: NOS Hydrographic Survey , Chesapeake Bay, Virginia, 2000-11-09

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  3. F00305: NOS Hydrographic Survey , Chesapeake Bay, Maryland and Virginia, 1987-09-14

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  4. H11407: NOS Hydrographic Survey , Southern Chesapeake Bay, Virginia, 2005-10-20

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  5. F00307: NOS Hydrographic Survey , Chesapeake Bay, Maryland and Virginia, 1987-11-20

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  6. F00306: NOS Hydrographic Survey , Chesapeake Bay, Maryland and Virginia, 1987-10-29

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  7. F00308: NOS Hydrographic Survey , Chesapeake Bay, Maryland and Virginia, 1987-11-24

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  8. F00259: NOS Hydrographic Survey , Southern Chesapeake Bay, Virginia, 1984-05-22

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  9. F00275: NOS Hydrographic Survey , Chesapeake Bay, Maryland and Virginia, 1985-12-11

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  10. H11401: NOS Hydrographic Survey , Approaches to Chesapeake Bay, Virginia, 2005-06-09

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  11. F00304: NOS Hydrographic Survey , Chesapeake Bay, Maryland and Virginia, 1987-08-14

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  12. H11529: NOS Hydrographic Survey , Southern Chesapeake Bay, Virginia, 2006-10-16

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  13. H11027: NOS Hydrographic Survey , Northeast Approach to Chesapeake Bay, Virginia, 2001-07-10

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  14. H05237: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1932-11-18

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  15. H05295: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1933-10-29

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  16. H10212: NOS Hydrographic Survey , Chesapeake Bay, Craighill Channel Spoil Areas, 1983-08-16

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  17. F00220: NOS Hydrographic Survey , Wire Drag, East Coast Investigations, Chesapeake Bay, 1979-04-13

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  18. H12286: NOS Hydrographic Survey , Southern Chesapeake Bay, Virginia, 2011-06-01

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  19. H09099: NOS Hydrographic Survey , Chesapeake Bay Sealanes, Virginia, 1969-12-18

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  20. H11651: NOS Hydrographic Survey , Approaches to Chesapeake Bay, Virginia, 2007-05-21

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  1. H12041: NOS Hydrographic Survey , Southern Chesapeake Bay, Virginia, 2009-12-15

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  2. H12423: NOS Hydrographic Survey , Approaches to Chesapeake Bay, Virginia, 2012-09-09

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  3. H11323: NOS Hydrographic Survey , Approaches to Chesapeake Bay, Virginia, 2006-06-21

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  4. H12575: NOS Hydrographic Survey , Approaches to Chesapeake Bay, 2013-07-30

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  5. H10337: NOS Hydrographic Survey , Entrance to Chesapeake Bay, Virginia, 1990-05-20

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  6. H12285: NOS Hydrographic Survey , Southern Chesapeake Bay, VA, 2012-07-28

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  7. H06375: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1938-10-20

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  8. H11450: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 2006-08-17

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  9. H07011: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1944-12-21

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  10. H12180: NOS Hydrographic Survey , Southern Chesapeake Bay, Virginia, 2010-10-10

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  11. H12502: NOS Hydrographic Survey , Approaches to Chesapeake Bay, Virginia, 2012-09-28

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  12. H05329: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1933-07-18

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  13. H06955: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1944-04-14

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  14. H06954: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1944-04-15

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  15. H06360: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1938-09-28

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  16. F00267: NOS Hydrographic Survey , Chesapeake Bay Hurricane Anchorages, Virginia, 1984-06-21

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  17. H10652: NOS Hydrographic Survey , Northern Chesapeake Bay, Maryland, 1997-08-11

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  18. H10632: NOS Hydrographic Survey , Upper Chesapeake Bay - Baltimore Harbor, Maryland, 1995-09-21

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  19. H10703: NOS Hydrographic Survey , Northern Chesapeake Bay, Maryland, 1998-03-25

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  20. H10752: NOS Hydrographic Survey , Northern Chesapeake Bay, Maryland, 1997-11-11

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  1. F00438: NOS Hydrographic Survey , Northern Chesapeake Bay - Baltimore Harbor, Maryland, 1998-05-20

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  2. H10934: NOS Hydrographic Survey , Upper Chesapeake Bay, Maryland, 2000-06-12

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  3. H10691: NOS Hydrographic Survey , Northern Chesapeake Bay, Maryland, 1996-11-06

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  4. H10745: NOS Hydrographic Survey , Chesapeake Bay, Nautilis Shoal, Virginia, 1997-05-14

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  5. H11503: NOS Hydrographic Survey , Central Chesapeake Bay, Virginia, 2006-09-18

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  6. H08083: NOS Hydrographic Survey , Chesapeake Bay, Virginia, 1953-10-09

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  7. H12040: NOS Hydrographic Survey , Southern Chesapeake Bay, Virginia, 2009-12-07

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  8. H11656: NOS Hydrographic Survey , Chesapeake Bay, Virginia, 2007-09-28

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  9. H12346: NOS Hydrographic Survey , Approaches to Chesapeake Bay, Virginia, 2011-11-10

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  10. H12421: NOS Hydrographic Survey , Southern Chesapeake Bay, Virginia, 2012-05-01

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  11. H08078: NOS Hydrographic Survey , Chesapeake Bay, Virginia, 1953-07-20

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  12. H10790: NOS Hydrographic Survey , Northern Chesapeake Bay - Baltimore Harbor, Maryland, 1998-06-30

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  13. H11603: NOS Hydrographic Survey , Lower Chesapeake Bay, Virginia, 2007-09-13

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  14. H12501: NOS Hydrographic Survey , Approaches to Chesapeake Bay, Virginia, 2012-09-11

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  15. H12044: NOS Hydrographic Survey , Southern Chesapeake Bay, Virginia, 2009-12-15

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  16. H12045: NOS Hydrographic Survey , Southern Chesapeake Bay, Virginia, 2009-12-14

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  17. H12304: NOS Hydrographic Survey , Central Chesapeake Bay, MD, 2012-06-18

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  18. H12367: NOS Hydrographic Survey , Central Chesapeake Bay, 2012-12-19

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    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  19. H12786: NOS Hydrographic Survey , Central Chesapeake Bay, 2015-10-07

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  20. F00454: NOS Hydrographic Survey , Upper Chesapeake Bay, Maryland, 1999-09-14

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  1. H11918: NOS Hydrographic Survey , Central Chesapeake Bay, 2010-05-05

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  2. H11598: NOS Hydrographic Survey , Central Chesapeake Bay, Maryland, 2008-11-12

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  3. F00607: NOS Hydrographic Survey , Approaches to Chesapeake Bay, Virginia, 2011-10-20

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  4. H05197: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1932-12-31

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  5. H06364: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1938-08-20

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  6. H07003: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1944-11-19

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  7. H06952: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1944-04-11

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  8. H10823: NOS Hydrographic Survey , Northern Chesapeake Bay - Baltimore Harbor, Maryland, 1998-11-13

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  9. H08079: NOS Hydrographic Survey , Chesapeake Bay, Virginia, 1953-09-04

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  10. H11653: NOS Hydrographic Survey , Chesapeake Bay, Virginia, 2007-09-26

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  11. H11301: NOS Hydrographic Survey , Approaches to Chesapeake Bay, Virginia, 2005-11-15

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  12. H07157: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1946-10-17

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  13. H07154: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1946-10-17

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  14. F00355: NOS Hydrographic Survey , Chesapeake Bay Entrance, Virginia, 1990-10-17

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  15. H07155: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1946-10-17

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  16. H07010: NOS Hydrographic Survey , Chesapeake Bay, Maryland, 1944-12-20

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  17. A review of benthic faunal surveys in San Francisco Bay

    Science.gov (United States)

    Nichols, Frederic H.

    1973-01-01

    During the past 60 years, considerable effort has been expended in studies of the relations of the biotic community and physicochemical characteristics of San Francisco Bay water. In very recent years these studies have emphasized the relations between the 'state of health' of bottom-living invertebrates (the benthos) and the levels of pollutants in the bay. Benthic organisms, generally sessile, are unable to escape deleterious environmental changes, and they reflect these changes in alterations of normal species composition of assemblages and species abundance. Data that expands understanding of these relations in urbanized areas such as San Francisco Bay are critical. Because of the implications of such data in control of water quality, the U.S. Geological Survey undertook a review of the results and major conclusions of San Francisco Bay benthic surveys. The size and species composition of faunal assemblages are largely controlled by the salinity of the water, the texture of the bottom sediments, and locally by wastes discharged into the bay. Efforts to describe the structure and function of benthic communities of the bay and to quantify the effects of waste discharge on them have been hampered by inconsistent and often faulty sampling methodology and species identification. Studies made show a lack of information on the normal life processes of the organisms concerned. The diversity index (a mathematical expression of the number of kinds of organisms present at a location), commonly used to describe the 'health' of the benthic community, has been employed without regard for the need for standardizing methodology and species identifications or for understanding natural biological processes that affect such mathematical indices. There are few reliable quantitative data on the distribution of benthic organisms in San Francisco Bay with which future assessments of the 'health' of the benthic community might be compared. Methods for study of the benthos must be

  18. Chesapeake Bay Climate Study Partnership: Undergraduate Student Experiential Learning on Microclimates at the University of Hawai'i, Hilo

    Science.gov (United States)

    Ozbay, G.; Sriharan, S.; Fan, C.; Adolf, J.

    2015-12-01

    Undergraduate student experiential learning activities focused on microclimates of Hawai'i Island, Hawai'i. Six students from Virginia State University, three students from Delaware State University and faculty advisors were hosted by the University of Hawai'i at Hilo (UHH) Department of Marine Science. This partnership provided integrated, cohesive, and innovative education and research capabilities to minority students on climate change science. Activities included a summer course, instrumentation training, field and laboratory research training, sampling, data collection, logging, analysis, interpretation, report preparation, and research presentation. Most training activities used samples collected during students' field sampling in Hilo Bay. Water quality and phytoplankton data were collected along a 220 degree line transect from the mouth of the Wailuku River to the pelagic zone outside of Hilo Bay into the Pacific Ocean to a distance of 15.5 km. Water clarity, turbidity, chlorophyll, physical water quality parameters, and atmospheric CO2 levels were measured along the transect. Phytoplankton samples were collected for analysis by Scanning Electron Microscopy and Flow Cytometry. Data showed the extent of anthropogenic activity on water quality, with implications for food web dynamics. In addition, atmospheric CO2 concentration, island vegetation, and GPS points were recorded throughout the island of Hawai'i to investigate how variations in microclimate, elevation, and land development affect the amount of CO2 in the atmosphere, vegetation, and water quality. Water quality results at locations near rivers were completely different from other study sites, requiring students' critical thinking skills to find possible reasons for the difference. Our data show a correlation between population density and CO2 concentrations. Anthropogenic activities affecting CO2 and ocean conditions in Hawaiian microclimates can potentially have deleterious effects on the life

  19. Conductivity, temperature, depth, fluorescence, optical backscatter, laser in-situ scattering and transmissivity, acoustic zooplankton biomass, net zooplankton counts, and suspended particle data from the RV HUGH R. SHARP in the upper Chesapeake Bay from February 23 through 26, 2007 as part of the Bio-Physical Interaction in the Turbidity Maximum (BITMAX-II) program (NODC Accession 0062884)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data set contains Cruise Reports and CTD data from 8 main cruises in the upper Chesapeake Bay on board the R/V Hugh R. Sharp from February 2007 to October 2008 ....

  20. Marine predator surveys in Glacier Bay National Park and Preserve

    Science.gov (United States)

    Bodkin, James L.; Kloecker, Kimberly A.; Coletti, Heather A.; Esslinger, George G.; Monson, Daniel H.; Ballachey, Brenda E.

    2002-01-01

    Since 1999, vessel based surveys to estimate species composition, distribution and relative abundance of marine birds and mammals have been conducted along coastal and pelagic (offshore) transects in Glacier Bay, Alaska. Surveys have been conducted during winter (November-March) and summer (June). This annual report presents the results of those surveys conducted in March and June of 2001. Following completion of surveys in 2002 we will provide a final report of the results of all surveys conducted between 1999 and 2002. Glacier Bay supports diverse and abundant assemblages of marine birds and mammals. In 2001 we identified 58 species of bird, 7 species of marine mammal, and 6 species of terrestrial mammal on transects sampled during winter and summer. Of course all species are not equally abundant. Among all taxa, in both seasons, sea ducks were the numerically dominant group. In their roles as consumers and because of their generally large size, marine mammals are also likely important in the consumption of energy produced in the Glacier Bay ecosystem. Most common and abundant marine birds and mammals can be placed in either a fish based (e.g. alcids and pinnipeds), or a benthic invertebrate (e.g. sea ducks and sea otters) based food web. Distinct differences in the species composition and abundance of marine birds were observed between winter and summer surveys. Winter marine bird assemblages were dominated numerically (> 11,000; 65% of all birds) by a relatively few species of sea ducks (scoters, goldeneye, Bufflehead, Harlequin and Long-tailed ducks). The sea ducks were distributed almost exclusively along near shore habitats. The prevalence of sea ducks during the March surveys indicates the importance of Glacier Bay as a wintering area for this poorly understood group of animals that occupy a high trophic position in a principally benthic invertebrate (mussel and clam) food web. Marine mammal assemblages were generally consistent between seasons, although

  1. Enhanced dry deposition of nitrogen pollution near coastlines: A case study covering the Chesapeake Bay estuary and Atlantic Ocean coastline

    Science.gov (United States)

    Loughner, Christopher P.; Tzortziou, Maria; Shroder, Shulamit; Pickering, Kenneth E.

    2016-12-01

    Atmospheric deposition of nitrogen pollution is one of the major sources of nitrogen to many terrestrial and aquatic ecosystems, worldwide. This modeling study suggests that coastlines frequently experience disproportionally high dry deposition of reactive nitrogen. High concentrations of air pollution from coastal cities often accumulate over adjacent estuaries and coastal waters due to low dry deposition rates over the water and a shallow marine boundary layer trapping marine emissions. As high concentrations of pollutants over the water are transported inland, enhanced dry deposition occurs onshore along the coastlines. Large spatial gradients in air pollutants and deposition totals are simulated along the coastline with decreasing concentrations/deposition as the distance from the water increases. As pollutants are transported onshore, air pollution mixing ratios near the surface decrease due to removal by dry deposition, vertical dilution due to deeper mixing layer heights, and decrease in friction velocity as a function of distance inland from the coastline. Ammonium nitrate formation near agricultural ammonia sources, sodium nitrate formation near coastal areas with atmospheric sea-salt loadings, and particulate growth via water uptake also contribute to large nitrate dry deposition totals at the coastline. Gradients in dry N deposition are evident over a monthly time scale and are enhanced during sea and bay breeze events. Current existing N-deposition monitoring networks do not capture the large spatial gradients of ammonium, nitrate, and nitric acid concentrations near coastlines predicted by the model due to the coarse spatial density distribution of monitoring sites.

  2. Impacts of Watershed Characteristics and Crop Rotations on Winter Cover Crop Nitrate-Nitrogen Uptake Capacity within Agricultural Watersheds in the Chesapeake Bay Region.

    Science.gov (United States)

    Lee, Sangchul; Yeo, In-Young; Sadeghi, Ali M; McCarty, Gregory W; Hively, W Dean; Lang, Megan W

    2016-01-01

    The adoption rate of winter cover crops (WCCs) as an effective conservation management practice to help reduce agricultural nutrient loads in the Chesapeake Bay (CB) is increasing. However, the WCC potential for water quality improvement has not been fully realized at the watershed scale. This study was conducted to evaluate the long-term impact of WCCs on hydrology and NO3-N loads in two adjacent watersheds and to identify key management factors that affect the effectiveness of WCCs using the Soil and Water Assessment Tool (SWAT) and statistical methods. Simulation results indicated that WCCs are effective for reducing NO3-N loads and their performance varied based on planting date, species, soil characteristics, and crop rotations. Early-planted WCCs outperformed late-planted WCCs on the reduction of NO3-N loads and early-planted rye (RE) reduced NO3-N loads by ~49.3% compared to the baseline (no WCC). The WCCs were more effective in a watershed dominated by well-drained soils with increased reductions in NO3-N fluxes of ~2.5 kg N·ha-1 delivered to streams and ~10.1 kg N·ha-1 leached into groundwater compared to poorly-drained soils. Well-drained agricultural lands had higher transport of NO3-N in the soil profile and groundwater due to increased N leaching. Poorly-drained agricultural lands had lower NO3-N due to extensive drainage ditches and anaerobic soil conditions promoting denitrification. The performance of WCCs varied by crop rotations (i.e., continuous corn and corn-soybean), with increased N uptake following soybean crops due to the increased soil mineral N availability by mineralization of soybean residue compared to corn residue. The WCCs can reduce N leaching where baseline NO3-N loads are high in well-drained soils and/or when residual and mineralized N availability is high due to the cropping practices. The findings suggested that WCC implementation plans should be established in watersheds according to local edaphic and agronomic

  3. Impacts of Watershed Characteristics and Crop Rotations on Winter Cover Crop Nitrate-Nitrogen Uptake Capacity within Agricultural Watersheds in the Chesapeake Bay Region.

    Directory of Open Access Journals (Sweden)

    Sangchul Lee

    Full Text Available The adoption rate of winter cover crops (WCCs as an effective conservation management practice to help reduce agricultural nutrient loads in the Chesapeake Bay (CB is increasing. However, the WCC potential for water quality improvement has not been fully realized at the watershed scale. This study was conducted to evaluate the long-term impact of WCCs on hydrology and NO3-N loads in two adjacent watersheds and to identify key management factors that affect the effectiveness of WCCs using the Soil and Water Assessment Tool (SWAT and statistical methods. Simulation results indicated that WCCs are effective for reducing NO3-N loads and their performance varied based on planting date, species, soil characteristics, and crop rotations. Early-planted WCCs outperformed late-planted WCCs on the reduction of NO3-N loads and early-planted rye (RE reduced NO3-N loads by ~49.3% compared to the baseline (no WCC. The WCCs were more effective in a watershed dominated by well-drained soils with increased reductions in NO3-N fluxes of ~2.5 kg N·ha-1 delivered to streams and ~10.1 kg N·ha-1 leached into groundwater compared to poorly-drained soils. Well-drained agricultural lands had higher transport of NO3-N in the soil profile and groundwater due to increased N leaching. Poorly-drained agricultural lands had lower NO3-N due to extensive drainage ditches and anaerobic soil conditions promoting denitrification. The performance of WCCs varied by crop rotations (i.e., continuous corn and corn-soybean, with increased N uptake following soybean crops due to the increased soil mineral N availability by mineralization of soybean residue compared to corn residue. The WCCs can reduce N leaching where baseline NO3-N loads are high in well-drained soils and/or when residual and mineralized N availability is high due to the cropping practices. The findings suggested that WCC implementation plans should be established in watersheds according to local edaphic and agronomic

  4. Distribution, Origin, and Realtions to Flow of Salty Ground Water Along the Western Margin of the Chesapeake Bay Impact Structure in Eastern Virginia

    Science.gov (United States)

    McFarland, R.; Bruce, S.

    2002-05-01

    The Chesapeake Bay impact structure closely coincides with parts of some aquifers in eastern Virginia that contain saltwater as much as 30 miles landward of the coast. The impact structure has thereby been inferred to play some role in controlling the presence of this "inland saltwater wedge", which formed under unstressed conditions prior to present-day ground-water withdrawals. That the impact severely disrupted the previously stratified sediments casts doubt on conceptualizations of a regionally contiguous, vertically layered system of aquifers and confining units. In addition, large and increasing ground-water withdrawals have resulted in continuing water-level declines and altered flow directions that create the potential for saltwater intrusion. Hence, the origin and emplacement of the saltwater must be known to predict its reaction to stresses being placed upon the flow system. Specific conductances and concentrations of chloride in ground water along the western margin of the impact structure reflect a transitional interface between freshwater to the west and seawater to the east that coincides aerially with the margin of the impact structure. Ratios of bromide to chloride and chlorine-36 to total chloride, and of stable hydrogen and oxygen isotopes, indicate chloride to have originated primarily from mixing of freshwater and seawater across the interface. In addition, deep ground water east of the interface having specific conductances which exceed that of seawater likely resulted from partial evaporation of seawater, either (1) in restricted coastal environments under arid conditions, (2) by rapid vaporization caused by the impact event, and (or) (3) by residual heat and associated hydrothermal activity following the impact. Mixing of freshwater and seawater has been theorized to take place in a "differential flushing" manner that left residual seawater to form the saltwater wedge. Seawater emplaced during inundation of the land surface persisted around

  5. Impact of Hurricane Irene on Vibrio vulnificus and Vibrio parahaemolyticus concentrations in surface water, sediment and cultured oysters in the Chesapeake Bay, Maryland, USA

    Directory of Open Access Journals (Sweden)

    Kristi S Shaw

    2014-05-01

    Full Text Available To determine if a storm event (i.e., high winds, large volumes of precipitation could alter concentrations of Vibrio vulnificus and Vibrio parahaemolyticus in aquacultured oysters (Crassostrea virginica and associated surface water and sediment, this study followed a sampling timeline before and after Hurricane Irene impacted the Chesapeake Bay estuary in late August 2011. Aquacultured oysters were sampled from two levels in the water column: surface 0.3 m and near-bottom just above the sediment. Concentrations of each Vibrio spp. and associated virulence genes were measured in oysters with a combination of real-time PCR and most probable number enrichment methods, and in sediment and surface water with real-time PCR. While concentration shifts of each Vibrio species were apparent post-storm, statistical tests indicated no significant change in concentration change for either Vibrio species by location (surface or near bottom oysters or date sampled (oyster tissue, surface water and sediment concentrations. V. vulnificus in oyster tissue was correlated with total suspended solids (r=0.41, p=0.04, and V. vulnificus in sediment was correlated with secchi depth (r=-0.93, p< 0.01, salinity (r=-0.46, p=0.02, tidal height (r=-0.45, p=0.03, and surface water V. vulnificus (r=0.98, p< 0.01. V. parahaemolyticus in oyster tissue did not correlate with environmental measurements, but V. parahaemolyticus in sediment and surface water correlated with several measurements including secchi depth (r=-0.48, p=0.02[sediment]; r=-0.97 p< 0.01[surface water] and tidal height (r=-0.96. p< 0.01[sediment], r=-0.59,p< 0.01 [surface water]. The concentrations of Vibrio spp. were higher in oysters relative to other studies (average V. vulnificus 4x105 MPN g-1, V. parahaemolyticus 1x105 MPN g-1, and virulence-associated genes were detected in most oyster samples. This study provides a first estimate of storm-related Vibrio density changes in oyster tissues, sediment and

  6. Marine magnetic survey and onshore gravity and magnetic survey, San Pablo Bay, northern California

    Science.gov (United States)

    Ponce, David A.; Denton, Kevin M.; Watt, Janet T.

    2016-09-12

    IntroductionFrom November 2011 to August 2015, the U.S. Geological Survey (USGS) collected more than 1,000 line-kilometers (length of lines surveyed in kilometers) of marine magnetic data on San Pablo Bay, 98 onshore gravity stations, and over 27 line-kilometers of ground magnetic data in northern California. Combined magnetic and gravity investigations were undertaken to study subsurface geologic structures as an aid in understanding the geologic framework and earthquake hazard potential in the San Francisco Bay Area. Furthermore, marine magnetic data illuminate local subsurface geologic features in the shallow crust beneath San Pablo Bay where geologic exposure is absent.Magnetic and gravity methods, which reflect contrasting physical properties of the subsurface, are ideal for studying San Pablo Bay. Exposed rock units surrounding San Pablo Bay consist mainly of Jurassic Coast Range ophiolite, Great Valley sequence, Franciscan Complex rocks, Miocene sedimentary rocks, and unconsolidated alluvium (Graymer and others, 2006). The contrasting magnetic and density properties of these rocks enable us to map their subsurface extent.

  7. A survey of molecular marker compounds in sediments of San Francisco Bay, California

    Science.gov (United States)

    Hostettler, Frances D.; Rapp, John B.; Geological Survey (U.S.) Pereira, Wilfred E.; Kvenvolden, Keith A.

    1994-01-01

    An areal survey of surficial sediments in San Francisco Bay has been conducted to evaluate the presence of extractable organic compounds. Molecular marker compounds studied include hydrocarbons (PAH's), chlorinated pesticides, and other organic compounds that provide information on sources of organic input into the Bay. Fairly uniform source profiles are seen throughout the Bay. Biomarker profiles contain mature constituents indicating anthropogenic influences and extensive sediment reworking. The dominant input signatures in San Francisco Bay sediment are those of anthropogenic PAH's from combustion and other sources, and long chain n-alkanes and n-aldehydes from terrigenous vascular plants. A comparison of the sums of the combustion PAH's and the terrigenous n-alkanes shows that an anthropogenic influence is dominant in the most urban parts of the Bay close to shore, and in mid-Bay channel areas, and a terrigenous signature is dominant nearshore in San Pablo Bay and at the southernmost station in South Bay.

  8. National Wildlife Refuge Visitor Survey 2012: Individual refuge results for Back Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the National Wildlife Refuge Visitor Survey for Back Bay National Wildlife Refuge and is part of the USGS Data Series 754. The survey was...

  9. Reconnaissance survey of nonpoint source pesticides in Maryland surface waters

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — As part of the Chesapeake Bay Agreement, the "Maryland Toxics Reduction Strategy for the Chesapeake Bay and its Tributaries" committed the State to identify the most...

  10. AFSC/REFM: Nearshore fish survey in northern Bristol Bay, Alaska, July-August 2009

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project consisted of a nearshore fish, invertebrate, and habitat survey in northern Bristol Bay, Alaska. A 32-ft. gillnet vessel, the F/V Willow was chartered...

  11. Proposed South San Diego Bay National Wildlife Refuge: Level III preaquisition survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A Level III Contaminant Preaquisition Survey was conducted during 1992 in the south San Diego Bay area to evaluate potential hazards to trustee resources and/or...

  12. Reef fish survey data from Fagatele Bay, American Samoa during November of 2007 (NODC Accession 0068717)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish surveys were conducted in November 2007 using visual census techniques at Fagatele Bay under the guidance of Dr. Alison Green, the Nature Conservancy. This data...

  13. Reef Fish Surveys for Fagatele Bay, American Samoa, 2007 (NODC Accession 0068717)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish surveys were conducted in November 2007 using visual census techniques at Fagatele Bay under the guidance of Dr. Alison Green, the Nature Conservancy. This...

  14. Summary of the 1998 Spawning Survey of Horseshoe Crabs Along the Delaware Bay Shore

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The spawning survey of horseshoe crabs was conducted along the shores of Delaware Bay for the ninth year. Counts of spawning horseshoe crabs was performed by trained...

  15. 土地利用及不透水地表对河流流量的影响%Impacts of Land Use and Impervious Surface on Stream Flow Metrics in Chesapeake Bay Watershed

    Institute of Scientific and Technical Information of China (English)

    田迪; 李叙勇; Donald E. Weller; 白中科

    2011-01-01

    Using daily discharge data from the US Geological Survey, we calculated 34 stream flow metrics for 150 watersheds (area <282 km ) within the Chesapeake Bay basin, and selected 17 of the metrics. We quantified the proportions of forest, agriculture, grassland, developed land, and impervious surface in each watershed. For each of the three physiographic provinces, we correlated the flow metrics with the land cover proportions to elucidate how different land cover types affect the flow regime. Higher proportions of forest increased stream flow in relatively dry winters or springs and reduced stream flow in comparatively rainy autumns. Higher forest proportions also reduced flooding, prolonged pulses of higher flow, and reduced flow variability. Higher proportions of agriculture reduced flow variability and prolonged pulses of higher flow in all physiographic provinces and reduced flooding in the highland physiographic provinces. Higher grassland proportions reduced flooding and flow variability and prolonged high flow pulses in all provinces. Higher proportions of developed land and impervious surface reduced infiltration, increased flooding and flow during high rainfall periods, intensified flow variability, and shortened high flow pulses; there are different hydrologic effects in different urbanized areas.%利用美国地质调查局的逐日连续流量数据计算了美国切斯比克湾地区150个小流域的34个河流流量指标,并在整个区域和划分的3个自然地理区对选择的17个指标与4种土地利用类型和不透水地表做了相关分析。结果表明,森林在降水较少的冬春两季增加流量,雨量较高的秋季减少流量,森林面积比例的增加可以削减洪峰、延长洪峰历时、稳定流量变化。农业用地比例的增加表现为稳定流量变化,延长洪峰历时,在高原地区还可以削减洪峰流量。草地比例的提高均表现为削减洪峰流量,稳定流量变化,延长洪

  16. Baseline surveys of Lac Bay benthic and fish communities, Bonaire

    NARCIS (Netherlands)

    Debrot, A.O.; Hylkema, A.; Vogelaar, W.; Meesters, H.W.G.; Engel, M.S.; Leon, R.; Prud'homme van Reine, W.F.; Nagelkerken, I.

    2012-01-01

    Lac Bay is a clear-water, 5 m deep shallow tropical lagoon of 7 km2 opening onto the wave and wind exposed east coast of the island of Bonaire, southern Caribbean. Over the last decades land reclamation by mangroves in Lac has been expanding the surface of turbid, saline backwaters into the bay at a

  17. Bacterial community biodiversity in estuaries and its controlling factors:a case study in Chesapeake Bay%河口细菌群落多样性及其控制因素:以切萨皮克湾为例

    Institute of Scientific and Technical Information of China (English)

    阚金军; 孙军

    2011-01-01

    Estuaries are among the most productive and dynamic aquatic ecosystems on earth, due to the mixing of fresh and salt waters and significant recycling of nutrients and organic matters. Sitting in a transitional zone, bacterial communities in an estuary typically harbor representatives of both freshwater and marine groups: Alphaproteobacteria, Betaproteobacteria, Gatnmaproteobacteria, Cyanobacteria (Synechococcus), Bacteroidetes, Actinobacteria, and Verrucomicrobia. In addition, estuaries such as Chesapeake Bay also contain their own unique bacterial signatures including the SARI 1 group, Roseobacter, SAR86, and Actinobacteria subclades, suggesting the ecological adaptation of organisms endemic to the Bay or perhaps, to large temperate estuaries in general. Relative to spatial variations, remarkable seasonal shifts and recurring annual patterns were identified in Chesapeake Bay bacterial communities. Besides water residence time and bacterial growth rate, many other factors are potential driving forces for the microbial diversity and bacterial population dynamics we observed. Temporal variations in bacterial communities were best explained by change in chlorophyll a (Chi a) and water temperature, while other factors such as dissolved oxygen, ammonia, nitrite and nitrate, and viral abundance also appeared to contribute to seasonal succession. Recently, the applications of community-based genomics and postgenomics (transcriptomics and proteomics) have allowed us to study the comprehensive gene diversity and gene expression directly from natural microbial communities. We predict that further studies and analyses of these genes and proteins will deliver new discoveries regarding the composition and function of microbial communities in aquatic environments.%咸淡水的混合和重要营养盐与有机物的再循环,使得河口成为地球上生产力较高而动态变化明显的水生生态系统.一个典型的河口区断面中,细菌群落包含了一些从

  18. Water Quality Assessment of DoD Installations/Facilities in the Chesapeake Bay Region. Phase 3. Volume 2. Overall Approach, Findings and Recommendations.

    Science.gov (United States)

    1987-11-01

    to quantify, where possible, the impacts of an installation on water quality in terms of: 1) conventional poilu - tants (nutrient, coliform and BOD...wildlife are the more visible manifestations of ecosystems in the estuary. Actually, there are many complex physico -chemical-biological interactions...that environmental stresses and rep’,- , in some areas of the Bay than in ot her.. 1l I, development of a segmentation scheme of the e ,ar. physico

  19. The Chesapeake Laser Tracker in Industrial Metrology

    Energy Technology Data Exchange (ETDEWEB)

    Ruland, Robert E.; /SLAC

    2005-08-16

    In the summer of 1992, the survey and alignment team at the Stanford Linear Accelerator Center acquired a CMS3000 laser tracker manufactured by Chesapeake Laser Systems in Lanham, Maryland. This paper gives a description of the principles of operation and calibration of the tracker. Several applications are explained and the results shared.

  20. Petrographic and geochemical comparisons between the lower crystalline basement-derived section and the granite megablock and amphibolite megablock of the Eyreville-B core, Chesapeake Bay impact structure

    Science.gov (United States)

    Townsend, Gabrielle N.; Gibson, Roger L.; Horton, J. Wright; Reimold, Wolf Uwe; Schmitt, Ralf T.; Bartosova, Katerina

    2009-01-01

    The Eyreville B core from the Chesapeake Bay impact structure, Virginia, USA, contains a lower basement-derived section (1551.19 m to 1766.32 m deep) and two megablocks of dominantly (1) amphibolite (1376.38 m to 1389.35 m deep) and (2) granite (1095.74 m to 1371.11 m deep), which are separated by an impactite succession. Metasedimentary rocks (muscovite-quartz-plagioclase-biotite-graphite ± fibrolite ± garnet ± tourmaline ± pyrite ± rutile ± pyrrhotite mica schist, hornblende-plagioclase-epidote-biotite-K-feldspar-quartz-titanite-calcite amphibolite, and vesuvianite-plagioclase-quartz-epidote calc-silicate rock) are dominant in the upper part of the lower basement-derived section, and they are intruded by pegmatitic to coarse-grained granite (K-feldspar-plagioclase-quartz-muscovite ± biotite ± garnet) that increases in volume proportion downward. The granite megablock contains both gneissic and weakly or nonfoliated biotite granite varieties (K-feldspar-quartz-plagioclase-biotite ± muscovite ± pyrite), with small schist xenoliths consisting of biotite-plagioclase-quartz ± epidote ± amphibole. The lower basement-derived section and both megablocks exhibit similar middle- to upper-amphibolite-facies metamorphic grades that suggest they might represent parts of a single terrane. However, the mica schists in the lower basement-derived sequence and in the megablock xenoliths show differences in both mineralogy and whole-rock chemistry that suggest a more mafic source for the xenoliths. Similarly, the mineralogy of the amphibolite in the lower basement-derived section and its association with calc-silicate rock suggest a sedimentary protolith, whereas the bulk-rock and mineral chemistry of the megablock amphibolite indicate an igneous protolith. The lower basement-derived granite also shows bulk chemical and mineralogical differences from the megablock gneissic and biotite granites.

  1. JPEG images of photographs of vibracores collected by the U.S. Geological Survey within Apalachicola Bay, Florida, 2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected using a Rossfelder electric percussive...

  2. Back Bay National Wildlife Refuge: 2001 Marshbird Callback Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes marshbird callback survey results for 2000. Last year's selection of points based on three mini-surveys was used as the basis of the route...

  3. Back Bay National Wildlife Refuge: 2000 Marshbird Callback Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes marshbird callback survey results for 2000. Last year's selection of points based on three mini-surveys was used as the basis of the route...

  4. Anuran Survey Back Bay National Wildlife Refuge: With Recommendations for Future Surveys

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — To establish baseline data and to monitor change over time to the Back Bay National Wildlife Refuge's(BBNWR) anuran populations the U.S. Fish and Wildlife Service,...

  5. IRIS Chirp Seismic-Reflection Profile JPEG Images Collected in Apalachicola Bay on U.S. Geological Survey Cruise 06001

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Apalachicola Bay and St. George Sound contain the largest oyster fishery in Florida, and the growth and distribution of the numerous oyster reefs here are the...

  6. National Wildlife Refuge Visitor Survey 2012: Individual refuge results for Don Edwards San Francisco Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the National Wildlife Refuge Visitor Survey for Don Edwards San Francisco Bay National Wildlife Refuge and is part of the USGS Data Series...

  7. 2010 bathymetric survey and digital elevation model of Corte Madera Bay, California

    Science.gov (United States)

    Foxgrover, Amy C.; Finlayson, David P.; Jaffe, Bruce E.; Takekawa, John Y.; Thorne, Karen M.; Spragens, Kyle A.

    2011-01-01

    A high-resolution bathymetric survey of Corte Madera Bay, California, was collected in early 2010 in support of a collaborative research project initiated by the San Francisco Bay Conservation and Development Commission and funded by the U.S. Environmental Protection Agency. The primary objective of the Innovative Wetland Adaptation in the Lower Corte Madera Creek Watershed Project is to develop shoreline adaptation strategies to future sea-level rise based upon sound science. Fundamental to this research was the development of an of an up-to-date, high-resolution digital elevation model (DEM) extending from the subtidal environment through the surrounding intertidal marsh. We provide bathymetric data collected by the U.S. Geological Survey and have merged the bathymetry with a 1-m resolution aerial lidar data set that was collected by the National Oceanic and Atmospheric Administration during the same time period to create a seamless, high-resolution DEM of Corte Madera Bay and the surrounding topography. The bathymetric and DEM surfaces are provided at both 1 m and 10 m resolutions formatted as both X, Y, Z text files and ESRI Arc ASCII files, which are accompanied by Federal Geographic Data Committee compliant metadata.

  8. Geological, geochemical, and geophysical survey of the geothermal resources at Hot Springs Bay Valley, Akutan Island, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Motyka, R.J.; Wescott, E.M.; Turner, D.L.; Swanson, S.E.; Romick, J.D.; Moorman, M.A.; Poreda, R.J.; Witte, W.; Petzinger, B.; Allely, R.D.

    1985-01-01

    An extensive survey was conducted of the geothermal resource potential of Hot Springs Bay Valley on Akutan Island. A topographic base map was constructed, geologic mapping, geophysical and geochemical surveys were conducted, and the thermal waters and fumarolic gases were analyzed for major and minor element species and stable isotope composition. (ACR)

  9. Chesapeake Bay Low Freshwater Inflow Study.

    Science.gov (United States)

    1984-09-01

    quinquecirrha sea nettle Mnemiopsis leidyi comb jelly, ctenophore Streblospio benedicti polychaete worm Mulinia lateralis coot clam Mercenaria...Mnemiopous leidyi - comb jelly, ctenophore ment freshwater inflows during all Streblospio benedicti - polychaete worm seasons of the year thereby providing

  10. Canvasback Food Habits in Chesapeake Bay

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Food habits analyses were conducted on the gullet and gizzards of 153 canvasbacks (Aythya valisineria) collected at night from eight major wintering areas in...

  11. Macrobenthic Communities of the Lower Chesapeake Bay.

    Science.gov (United States)

    1984-10-01

    ECHINODERMATA :ECHINOIDEA Arbacij Runlctulata (Lamarck) Echinarachnius Parma (Larmack) ECHINODERMATA :HOLOTHURO-DEA Holothuroidea spp. Leptosynapta ... inhaerens (Ayres) ECHINODERMATA :OPHIUROIDEA Ophiuroidea spp. * HEMICHORDATA Saccoglossus kowalewskii (Agassiz) CHORDATA :CEPHALOCHORDATA Branchiostoma

  12. Airborne gamma-ray spectrometer and magnetometer survey Coos Bay, Oregon. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-01

    During the months of August, September, and October of 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over ten (10) areas over northern California and southwestern Oregon. These include the 2/sup 0/ x 1/sup 0/ NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1/sup 0/ x 2/sup 0/ areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Coos Bay, Oregon, map area. Line spacing was generally six miles for east/west traverses and eighteen miles for north/south tie lines over the northern one-half of the area. Traverses and tie lines were flown at three miles and twelve miles respectively over the southern one-half of the area. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 863.8 line miles are in this quadrangle.

  13. JPEG images of summary sheets of core content and analysis of vibracores collected by the U.S. Geological Survey within Apalachicola Bay, Florida, 2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected using a Rossfelder electric percussive...

  14. JPEG images of seismic reflection profiles with adjacent vibracore locations collected by the U.S. Geological Survey within Apalachicola Bay, Florida (2005-2007)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected using a Rossfelder electric vibracore...

  15. Location and analysis information of vibracores collected by the U.S. Geological Survey within Apalachicola Bay, Florida, 2007 (APP-07_CoreLocations, points)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected using a Rossfelder percussive (P-3)...

  16. PDF images of field description sheets from vibracores collected by the U.S. Geological Survey within Apalachicola Bay, Florida, 2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected using a Rossfelder electric percussive...

  17. Location and analysis of microfossil samples from vibracores collected by the U.S. Geological Survey within Apalachicola Bay, Florida, 2007 (APP-07_Microfossils, points)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected using a Rossfelder electric percussive...

  18. Location of radiocarbon age dates sampled from vibracores collected by the U.S. Geological Survey within Apalachicola Bay, Florida, 2007 (APP-07_AgeDates, points)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected using a Rossfelder electric percussive...

  19. Atchafalaya Bay, LA (G220) Bathymetric Digital ElevationModel (30 meter resolution) Derived From Source Hydrographic SurveySoundings Collected by NOAA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry for Atchafalaya Bay was derived from eleven surveys containing127,192 soundings. No surveys were omitted. The average separationbetween soundings was 130...

  20. Location and analysis of microfossil samples from vibracores collected by the U.S. Geological Survey within Apalachicola Bay, Florida, 2007 (APP-07_Microfossils, points)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected using a Rossfelder electric percussive...

  1. Location of radiocarbon age dates sampled from vibracores collected by the U.S. Geological Survey within Apalachicola Bay, Florida, 2007 (APP-07_AgeDates, points)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected using a Rossfelder electric percussive...

  2. Location and analysis information of vibracores collected by the U.S. Geological Survey within Apalachicola Bay, Florida, 2007 (APP-07_CoreLocations, points)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected using a Rossfelder percussive (P-3)...

  3. Active fault survey on the Tanlu fault zone in Laizhou Bay

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-cai; YANG Xi-ha; LI Chang-chuan; DENG Qi-dong; DU Xian-song; CHAO Hong-tai; WU Zi-quan; XIAO Lan-xi; SUN Zhao-ming; MIN Wei; LING Hong

    2006-01-01

    Shallow-depth acoustic reflection profiling survey has been conducted on the Tanlu fault zone in Laizhou Bay. It is found that the Tanlu fault zone is obviously active during the late Quaternary and it is still the dominating structure in this region. The Tanlu fault zone consists of two branches. The KL3 fault of the western branch is composed of several high angle normal faults which had been active during the period from the latest Pleistocene to early Holocene, dissected by a series of northeast or approximate east-west trending fault which leaped sediment of the late Pleistocene. The Longkou fault of the eastern branch consists of two right-laterally stepped segments. Late Quaternary offsets and growth strata developed along the Tanlu fault zone verify that the fault zone retained active in the latest Pleistocene to the early Holocene. The Anqiu-Juxian fault that passes through the middle of Shandong and corresponds to the Longkou fault is composed of a series of right-laterally stepped segments. The active faults along the eastern branch of the Tanlu fault zone from the Laizhou bay to the north of Anqiu make up a dextral simple shear deformation zone which is characterized by right-lateral strike-slip movement with dip-slip component during the late Quaternary.

  4. Sediment Sample Locations Collected in May 2014 from Barnegat Bay, New Jersey (U.S. Geological Survey Field Activity Number 2014-310-FA)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Barnegat Bay, located along the eastern shore of New Jersey, was significantly impacted by Hurricane Sandy in October 2012. Scientists from the U.S. Geological...

  5. Barnegat Bay surface and subsurface sediment physical parameters data from May 2014 (U.S. Geological Survey Field Activity Number 2014-310-FA)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Barnegat Bay, located along the eastern shore of New Jersey, was significantly impacted by Hurricane Sandy in October 2012. Scientists from the U.S. Geological...

  6. Gamma spectroscopy data for box core sediments collected from Barnegat Bay, New Jersey in May 2014 (U.S. Geological Survey Field Activity Number 2014-310-FA)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Barnegat Bay, located along the eastern shore of New Jersey, was significantly impacted by Hurricane Sandy in October 2012. Scientists from the U.S. Geological...

  7. National Wildlife Refuge Visitor Survey 2010/2011 : Individual refuge results for Occoquan Bay and Elizabeth Hartwell Mason Neck National Wildlife Refuges

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the National Wildlife Refuge Visitor Survey for Occoquan Bay and Elizabeth Hartwell Mason Neck National Wildlife Refuges and is part of the...

  8. Barnegat Bay surface and subsurface sediment physical parameters data from May 2014 (U.S. Geological Survey Field Activity Number 2014-310-FA)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Barnegat Bay, located along the eastern shore of New Jersey, was significantly impacted by Hurricane Sandy in October 2012. Scientists from the U.S. Geological...

  9. Sediment Sample Locations Collected in May 2014 from Barnegat Bay, New Jersey (U.S. Geological Survey Field Activity Number 2014-310-FA)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Barnegat Bay, located along the eastern shore of New Jersey, was significantly impacted by Hurricane Sandy in October 2012. Scientists from the U.S. Geological...

  10. A Survey of Macro-invertebrate Gleaning in the Banate Bay Intertidal Area, Eastern Panay Island

    Directory of Open Access Journals (Sweden)

    Annabelle del Norte-Campos

    2005-12-01

    Full Text Available The gleaning fishery on the intertidal areas of Banate Bay, eastern Panay was surveyed monthly fromFebruary 2002 to January 2003, to derive information on species composition, catch, catch rates, andannual value. Total biomass, gleaning and turnover rates were determined from a fishery-independentsurvey conducted in June 2005. Catches of the fishery consisted of a total of 17 species, comprised ofmollusks, crustaceans and a brachiopod. The bivalves Katelysia hiantina, Scapharca inaequivalvis, andGafrarium tumidum were the top three species, together comprising 88.79 % of the total catch. The totalmean daily catch per gleaner for all species was equivalent to 73.75 g/m-2/gleaner-1. Catch rate and catchvolume for the mollusks were highest between May-July and November-December, coinciding with thesouthwest and northeast monsoons, respectively. The large riverine inputs to the area, together with themangrove-derived organic matter, periodically resuspended by the tidal fluctuations, are seen asresponsible for increasing organic matter content of the substrates and abundance of the species. Totalannual catch of the fishery is estimated to range from 20,988.7 to 43, 527.62 kg, with a median value of31,205.6 kg. This latter value divided by the estimated total biomass in the area of 2,441. 03 kg gives aturnover rate of 12.8. The total annual catch for the entire fishery is equivalent to a total value of PhP421T to 897T/yr-1. The latter correspond to an annual income of PhP 14,043.90 to 29,904.67/gleaner-1/yr-1, small amounts which may be sustainable due to the high turnover rate of the system.

  11. A water bird survey in Bristol Bay and proposals for future studies

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This paper reports a preliminary attempt to census fall water bird populations in Bristol Bay within the zone from high tide to the 12-mile off shore limit. Aerial...

  12. Reconnaissance surveys of contaminants potentially affecting Green Bay and Gravel Island National Wildlife Refuges

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Biota samples were collected from several islands in Green Bay and Lake Michigan during 1987-1988 and were analyzed for various organochlorines and metals. PCBs and...

  13. Tracklines for bottom video collected using the MINI-SEABOSS sampler in Barnegat Bay, NJ by the U.S. Geological Survey during 3 surveys in 2012 and 2013 (Esri polyline shapefile, Geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water quality in the Barnegat Bay-Little Egg Harbor estuary along the New Jersey coast is the focus of a multidisciplinary research project begun in 2011 by the...

  14. Sediment sample locations and grain size results from samples collected in Barnegat Bay, NJ by the U.S. Geological Survey during 3 surveys in 2012 and 2013 (Esri point shapefile, Geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water quality in the Barnegat Bay-Little Egg Harbor estuary along the New Jersey coast is the focus of a multidisciplinary research project begun in 2011 by the...

  15. Survey lines along which EdgeTech 424 chirp seismic-reflection data were collected by the U.S. Geological Survey in the Barnegat Bay, NJ in 2011, 2012, and 2013 (Esri polyline shapefile, Geographic, WGS 84).

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water quality in the Barnegat Bay-Little Egg Harbor estuary along the New Jersey coast is the focus of a multidisciplinary research project begun in 2011 by the...

  16. Sea bottom gravity survey of Osaka bay and its study; Osakawan kaitei juryoku chosa to sono kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Komazawa, M. [Geological Survey of Japan, Tsukuba (Japan); Ota, Y.; Shibuya, S.; Kumai, M.; Murakami, M. [Japex Geoscience Institute, Inc., Tokyo (Japan)

    1996-05-01

    This paper reports a sea bottom gravity survey conducted with an objective to identify deep underground structure in the vicinity of the epicenter of the Hyogoken-Nanbu Earthquake. The surveyed areas are the whole Osaka Bay area north of the north latitude of 34 degrees and 20 minutes, and the eastern part of the Sea of Harima east of the east longitude of 134 degrees and 40 minutes, excluding the areas difficult of performing measurements. A square lattice with sides each about 2 km was arranged with 408 measurement points. The measurement was carried out by using an observation vessel mounted with a sea bottom gravimeter made by LaCoste and Romberg Corporation, which was lowered down to the sea bottom at the measurement points. Errors in positions and water depths at the gravity measuring points were suppressed to less than 0.002 minutes and 0.1 m, respectively. The measurement data were given necessary corrections by using a unified method applicable also to land areas, and a Bouguer anomaly chart was prepared. Based on the chart, this paper summarizes features in the Bouguer anomaly in the surveyed areas (such as the low-gravity anomaly band extending the central part of the Osaka bay from north-east to south-west, and the gradient structure existing on the Awaji island side). 6 refs., 1 fig.

  17. Baseline survey of anthropogenic pressures for the Lac Bay ecosystem, Bonaire

    NARCIS (Netherlands)

    Debrot, A.O.

    2012-01-01

    Lac Bay of Bonaire is a shallow non-estuarine lagoon of about 700 hectares, separated from the open sea by a shallow coral barrier-reef. It possesses the only major concentration of seagrass beds and mangroves of the island. It is a designated Ramsar wetland of international significance, an

  18. IndianRivBayYSI.xls: Temperature, conductivity and salinity data collected with a YSI 600 XLM multi-parameter sonde in Indian River Bay, Delaware, from April 12 to April 15, 2010 on U.S. Geological Survey Cruise 2010-006-FA

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A geophysical survey to delineate the fresh-saline groundwater interface and associated sub-bottom sedimentary structures beneath Indian River Bay, Delaware, was...

  19. Location and analysis of grain-size data sampled from vibracores collected by the U.S. Geological Survey within Apalachicola Bay, Florida, 2007 (APP-07_GrainSize, points)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected using a Rossfelder electric percussive...

  20. Seismic-reflection profile tracklines that are located adjacent to vibracores collected by the U.S. Geological Survey within Apalachicola Bay, Florida (Seismic_Cores_INT.shp, 2005-2007)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected using a Rossfelder electric percussive...

  1. Raw and modified raw continuous resistivity profiling data collected in the Indian River Bay, Delaware, on April 15, 2010, on U.S. Geological Survey Field Activity 2010-006-FA

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A geophysical survey to delineate the fresh-saline groundwater interface and associated sub-bottom sedimentary structures beneath Indian River Bay, Delaware, was...

  2. Location and analysis of grain-size data sampled from vibracores collected by the U.S. Geological Survey within Apalachicola Bay, Florida, 2007 (APP-07_GrainSize, points)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected using a Rossfelder electric percussive...

  3. Seismic-reflection profile tracklines that are located adjacent to vibracores collected by the U.S. Geological Survey within Apalachicola Bay, Florida (Seismic_Cores_INT.shp, 2005-2007)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected using a Rossfelder electric percussive...

  4. IR_ROUTES_CALIB.SHP: Shot-point calibrated trackline navigation for chirp seismic data collected in Indian River Bay, Delaware, on April 13, 2010, on U.S. Geological Survey Field Activity 2010-006-FA (Geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A geophysical survey to delineate the fresh-saline groundwater interface and associated sub-bottom sedimentary structures beneath Indian River Bay, Delaware, was...

  5. JD105HYPACK.SHP: Parsed HYPACK navigation from April 15, 2010 of U.S. Geological Survey Field Activity 2010-006-FA in Indian River Bay, Delaware (Geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A geophysical survey to delineate the fresh-saline groundwater interface and associated sub-bottom sedimentary structures beneath Indian River Bay, Delaware, was...

  6. IR_SEISNAV.SHP: Unique shot point navigation for chirp seismic data collected in Indian River Bay, Delaware, April 13, 2010, on U.S. Geological Survey Field Activity 2010-006-FA (Geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A geophysical survey to delineate the fresh-saline groundwater interface and associated sub-bottom sedimentary structures beneath Indian River Bay, Delaware, was...

  7. Summer surveys of the marine ecology of Creswell Bay, Somerset Island and Assistance Bay, Cornwallis Island, N.W.T. 1975

    National Research Council Canada - National Science Library

    Sekerak, A.D; Thomson, D; Bain, H; Acreman, J

    The primary objective of this study was to provide basic information on the plants and animals in the Assistance Bay and Creswell study areas so that comparisons between the two areas would be possible...

  8. Evaluation of estimation methods for meiofaunal biomass from a meiofaunal survey in Bohai Bay

    Institute of Scientific and Technical Information of China (English)

    张青田; 王新华; 胡桂坤

    2010-01-01

    Studies in the coastal area of Bohai Bay,China,from July 2006 to October 2007,suggest that the method of meiofaunal biomass estimation affected the meiofaunal analysis.Conventional estimation methods that use a unique mean individual weight value for nematodes to calculate total biomass may cause deviation of the results.A modified estimation method,named the Subsection Count Method (SCM),was also used to calculate meiofaunal biomass.This entails only a slight increase in workload but generates results of g...

  9. A survey of didymozoid trematodes of the barracuda Sphyraena obtusata from Kuwait Bay.

    Science.gov (United States)

    Abdul-Salam, J; Sreelatha, B S

    1993-08-01

    Examination of 120 yellow-finned barracudas, Sphyraena obtusata, from Kuwait Bay revealed 8 species of didymozoid trematodes encapsulated in pairs in the tissues. Four species of the didymozoids, Allodidymozoon operculare, Didymocylindrus sp., Didymocystis sp., and Didymocystoides sp., were found in the head region, 3 species, Didymozoon tetragynae, Lepidodidymozoon sinicum and Platocystoides polyaster, in external surfaces and 1 species, Allodidymozoon sp., in stomach wall. The didymozoid species collected constitute new geographic distribution records and occurrence of D. tetragynae and L. sinicum are new host records.

  10. Water quality measurements in San Francisco Bay by the U.S. Geological Survey, 1969-2015.

    Science.gov (United States)

    Schraga, Tara S; Cloern, James E

    2017-08-08

    The U.S. Geological Survey (USGS) maintains a place-based research program in San Francisco Bay (USA) that began in 1969 and continues, providing one of the longest records of water-quality measurements in a North American estuary. Constituents include salinity, temperature, light extinction coefficient, and concentrations of chlorophyll-a, dissolved oxygen, suspended particulate matter, nitrate, nitrite, ammonium, silicate, and phosphate. We describe the sampling program, analytical methods, structure of the data record, and how to access all measurements made from 1969 through 2015. We provide a summary of how these data have been used by USGS and other researchers to deepen understanding of how estuaries are structured and function differently from the river and ocean ecosystems they bridge.

  11. Water quality measurements in San Francisco Bay by the U.S. Geological Survey, 1969–2015

    Science.gov (United States)

    Schraga, Tara; Cloern, James E.

    2017-01-01

    The U.S. Geological Survey (USGS) maintains a place-based research program in San Francisco Bay (USA) that began in 1969 and continues, providing one of the longest records of water-quality measurements in a North American estuary. Constituents include salinity, temperature, light extinction coefficient, and concentrations of chlorophyll-a, dissolved oxygen, suspended particulate matter, nitrate, nitrite, ammonium, silicate, and phosphate. We describe the sampling program, analytical methods, structure of the data record, and how to access all measurements made from 1969 through 2015. We provide a summary of how these data have been used by USGS and other researchers to deepen understanding of how estuaries are structured and function differently from the river and ocean ecosystems they bridge.

  12. Spatial and temporal variation of stream chemistry associated with contrasting geology and land-use patterns in the Chesapeake Bay watershed—Summary of results from Smith Creek, Virginia; Upper Chester River, Maryland; Conewago Creek, Pennsylvania; and Difficult Run, Virginia, 2010–2013

    Science.gov (United States)

    Hyer, Kenneth E.; Denver, Judith M.; Langland, Michael J.; Webber, James S.; Böhlke, J.K.; Hively, W. Dean; Clune, John W.

    2016-11-17

    Despite widespread and ongoing implementation of conservation practices throughout the Chesapeake Bay watershed, water quality continues to be degraded by excess sediment and nutrient inputs. While the Chesapeake Bay Program has developed and maintains a large-scale and long-term monitoring network to detect improvements in water quality throughout the watershed, fewer resources have been allocated for monitoring smaller watersheds, even though water-quality improvements that may result from the implementation of conservation practices are likely to be first detected at smaller watershed scales.In 2010, the U.S. Geological Survey partnered with the U.S. Environmental Protection Agency and the U.S. Department of Agriculture to initiate water-quality monitoring in four selected small watersheds that were targeted for increased implementation of conservation practices. Smith Creek watershed is an agricultural watershed in the Shenandoah Valley of Virginia that is dominated by cattle and poultry production, and the Upper Chester River watershed is an agricultural watershed on the Eastern Shore of Maryland that is dominated by row-cropping activities. The Conewago Creek watershed is an agricultural watershed in southeastern Pennsylvania that is characterized by mixed agricultural activities. The fourth watershed, Difficult Run, is a suburban watershed in northern Virginia that is dominated by medium density residential development. The objective of this study was to investigate spatial and temporal variations in water chemistry and suspended sediment in these four relatively small watersheds that represent a range of land-use patterns and underlying geology to (1) characterize current water-quality conditions in these watersheds, and (2) identify the dominant sources, sinks, and transport processes in each watershed.The general study design involved two components. The first included intensive routine water-quality monitoring at an existing streamgage within each study

  13. Neah Bay to Cape Alava, Northwest Coast, Washington State - Topographic Survey Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data were collected by the SHOALS-1000T(Scanning Hydrographic Operational Airborne Lidar Survey)system which consists of an airborne laser transmitter/receiver...

  14. Tundra swan population survey in Bristol Bay, northern Alaska Peninsula, June 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A report on a tundra swan survey pilot study conducted in June 2002. The objectives of the project were to get initial population and productivity estimates for...

  15. Tundra swan population survey in Bristol Bay, northern Alaska Peninsula, 2003 and 2008

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Tundra swan (Cygnus columbianus) population surveys were conducted in spring and late summer of 2003 and 2008 according to the schedule established in the Alaska...

  16. Identification of largemouth bass virus in the introduced Northern snakehead inhabiting the Cheasapeake Bay watershed

    Science.gov (United States)

    Iwanowicz, Luke R.; Densmore, Christine L.; Hahn, Cassidy M.; McAllister, Phillip; Odenkirk, John

    2013-01-01

    The Northern Snakehead Channa argus is an introduced species that now inhabits the Chesapeake Bay. During a preliminary survey for introduced pathogens possibly harbored by these fish in Virginia waters, a filterable agent was isolated from five specimens that produced cytopathic effects in BF-2 cells. Based on PCR amplification and partial sequencing of the major capsid protein (MCP), DNA polymerase (DNApol), and DNA methyltransferase (Mtase) genes, the isolates were identified as Largemouth Bass virus (LMBV). Nucleotide sequences of the MCP (492 bp) and DNApol (419 pb) genes were 100% identical to those of LMBV. The nucleotide sequence of the Mtase (206 bp) gene was 99.5% identical to that of LMBV, and the single nucleotide substitution did not lead to a predicted amino acid coding change. This is the first report of LMBV from the Northern Snakehead, and provides evidence that noncentrarchid fishes may be susceptible to this virus.

  17. Survey lines along which EdgeTech 424 chirp seismic-reflection data were collected by the U.S. Geological Survey in the Barnegat Bay, NJ in 2011, 2012, and 2013 (Esri polyline shapefile, Geographic, WGS 84).

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water quality in the Barnegat Bay-Little Egg Harbor estuary along the New Jersey coast is the focus of a multidisciplinary research project begun in 2011 by the U.S....

  18. Tracklines for bottom video collected using the MINI-SEABOSS sampler in Barnegat Bay, NJ by the U.S. Geological Survey during 3 surveys in 2012 and 2013 (Esri polyline shapefile, Geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water quality in the Barnegat Bay-Little Egg Harbor estuary along the New Jersey coast is the focus of a multidisciplinary research project begun in 2011 by the U.S....

  19. Sediment sample locations and grain size results from samples collected in Barnegat Bay, NJ by the U.S. Geological Survey during 3 surveys in 2012 and 2013 (Esri point shapefile, Geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water quality in the Barnegat Bay-Little Egg Harbor estuary along the New Jersey coast is the focus of a multidisciplinary research project begun in 2011 by the U.S....

  20. Survey lines along which EdgeTech 424 chirp seismic-reflection data were collected by the U.S. Geological Survey in the Barnegat Bay, NJ in 2011, 2012, and 2013 (Esri polyline shapefile, Geographic, WGS 84).

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water quality in the Barnegat Bay-Little Egg Harbor estuary along the New Jersey coast is the focus of a multidisciplinary research project begun in 2011 by the U.S....

  1. Tracklines for bottom video collected using the MINI-SEABOSS sampler in Barnegat Bay, NJ by the U.S. Geological Survey during 3 surveys in 2012 and 2013 (Esri polyline shapefile, Geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water quality in the Barnegat Bay-Little Egg Harbor estuary along the New Jersey coast is the focus of a multidisciplinary research project begun in 2011 by the U.S....

  2. Sediment sample locations and grain size results from samples collected in Barnegat Bay, NJ by the U.S. Geological Survey during 3 surveys in 2012 and 2013 (Esri point shapefile, Geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water quality in the Barnegat Bay-Little Egg Harbor estuary along the New Jersey coast is the focus of a multidisciplinary research project begun in 2011 by the U.S....

  3. Histopathological survey of potential biomarkers for the assessment of contaminant related biological effects in species of fish and shellfish collected from Kuwait Bay, Arabian Gulf.

    Science.gov (United States)

    Stentiford, G D; Massoud, M S; Al-Mudhhi, S; Al-Sarawi, M A; Al-Enezi, M; Lyons, B P

    2014-07-01

    The marine environment in Kuwait is dominated by Kuwait Bay, a shallow, depositional habitat vital for the breeding and propagation of marine organisms. The bay receives effluent inputs from industrial centres, ports, sewage outflows along with discharges from power and desalination plants. The major classes of pollutant discharged into the bay include petroleum hydrocarbons, metals, nutrients, cooling water and hyper-saline water. Further, the bay has been historically impacted by a deliberate release of oil and contamination with ordnance and shipwrecks during the 1991 Gulf war. With an aim to establish an integrated pollution effects monitoring programme in Kuwait, this paper describes the application of a quality assured approach to conduct a histopathology baseline survey in oriental sole (Synaptura orientalis) and the large-toothed flounder (Pseudorhombus arsius), which are two potential sentinel flatfish species present in the Arabian Gulf. Liver and gonadal histopathology revealed a range of pathologies similar to those previously observed in European and American pollution effects surveys that utilise flatfish (including pathology markers indicative of possible carcinogenesis and endocrine disruption). Further, we extended these studies to invertebrates (Jinga prawn, Metapenaeus affinis and the grooved tiger prawn, Penaeus semisulcatus) found within the Arabian Gulf. Such baseline data is essential before attempts are made to develop integrated monitoring programmes that aim to assess the health of fish and shellfish in relation to chemical contamination.

  4. Chesapeake Inundation Prediction System (CIPS): A regional prototype for a national problem

    Science.gov (United States)

    Stamey, B.; Smith, W.; Carey, K.; Garbin, D.; Klein, F.; Wang, Hongfang; Shen, J.; Gong, W.; Cho, J.; Forrest, D.; Friedrichs, C.; Boicourt, W.; Li, M.; Koterba, M.; King, D.; Titlow, J.; Smith, E.; Siebers, A.; Billet, J.; Lee, J.; Manning, Douglas R.; Szatkowski, G.; Wilson, D.; Ahnert, P.; Ostrowski, J.

    2007-01-01

    Recent Hurricanes Katrina and Isabel, among others, not only demonstrated their immense destructive power, but also revealed the obvious, crucial need for improved storm surge forecasting and information delivery to save lives and property in future storms. Current operational methods and the storm surge and inundation products do not adequately meet requirements needed by Emergency Managers (EMs) at local, state, and federal levels to protect and inform our citizens. The Chesapeake Bay Inundation Prediction System (CIPS) is being developed to improve the accuracy, reliability, and capability of flooding forecasts for tropical cyclones and non-tropical wind systems such as nor'easters by modeling and visualizing expected on-land storm-surge inundation along the Chesapeake Bay and its tributaries. An initial prototype has been developed by a team of government, academic and industry partners through the Chesapeake Bay Observing System (CBOS) of the Mid-Atlantic Coastal Ocean Observing Regional Association (MACOORA) within the Integrated Ocean Observing System (IOOS). For demonstration purposes, this initial prototype was developed for the tidal Potomac River in the Washington, DC metropolitan area. The preliminary information from this prototype shows great potential as a mechanism by which NOAA National Weather Service (NWS) Forecast Offices (WFOs) can provide more specific and timely forecasts of likely inundation in individual localities from significant storm surge events. This prototype system has shown the potential to indicate flooding at the street level, at time intervals of an hour or less, and with vertical resolution of one foot or less. This information will significantly improve the ability of EMs and first responders to mitigate life and property loss and improve evacuation capabilities in individual communities. This paper provides an update and expansion of the initial prototype that was presented at the Oceans 2006 MTS/IEEE Conference in Boston, MA

  5. Sedimentary Data Collected in November 2015 From Old Tampa Bay, Florida (U.S. Geological Survey Field Activity Number 2015–341–FA)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The toxic dinoflagellate Pyrodinium bahamense (P. bahamense) produces recurring, persistent summer algal blooms in Old Tampa Bay, Florida, which degrade water...

  6. ESRI Binary 75-m Grid of the Lowstand Surface in Apalachicola Bay based on Seismic-Reflection Profiles Collected in 2006 from U.S. Geological Survey Cruise 06001 (LOWFILCLIP, UTM, Zone 16, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Apalachicola Bay and St. George Sound contain the largest oyster fishery in Florida, and the growth and distribution of the numerous oyster reefs here are the...

  7. ESRI Binary 75-m Grid of the Flooding Surface in Apalachicola Bay based on Seismic-Reflection Profiles Collected in 2006 from U.S. Geological Survey Cruise 06001 (FLOODSURF, UTM, Zone 16, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Apalachicola Bay and St. George Sound contain the largest oyster fishery in Florida, and the growth and distribution of the numerous oyster reefs here are the...

  8. ESRI Binary 75-m Grid of the Base of the Mud Isopach of Apalachicola Bay based on Seismic-Reflection Profiles Collected in 2006 from U.S. Geological Survey Cruise 06001 (BASEMUDISO, UTM, Zone 16, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Apalachicola Bay and St. George Sound contain the largest oyster fishery in Florida, and the growth and distribution of the numerous oyster reefs here are the...

  9. ESRI Binary 75-m Grid of the Base of the Mud Isopach of Apalachicola Bay based on Seismic-Reflection Profiles Collected in 2006 from U.S. Geological Survey Cruise 06001 (BASEMUDISO, UTM, Zone 16, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Apalachicola Bay and St. George Sound contain the largest oyster fishery in Florida, and the growth and distribution of the numerous oyster reefs here are the...

  10. Polyline-M Shapefile of Navigation Tracklines for Autonomous Surface Vessel IRIS Chirp Seismic Data in Apalachicola Bay collected on U.S. Geological Survey Cruise 06001 (ASV_LINES_CALIBRATED.SHP, Geographic, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Apalachicola Bay and St. George Sound contain the largest oyster fishery in Florida, and the growth and distribution of the numerous oyster reefs here are the...

  11. Sediment Grain-size Data from sediment grab samples and box cores collected in May 2014 from Barnegat Bay, New Jersey (U.S. Geological Survey Field Activity Numbers 2014-310-FA).

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Barnegat Bay, located along the eastern shore of New Jersey, was significantly impacted by Hurricane Sandy in October 2012. Scientists from the U.S. Geological...

  12. Alpha spectroscopy radioisotopic data for box core sediments collected from Barnegat Bay, New Jersey in May 2014 (U.S. Geological Survey Field Activity Number 2014-310-FA)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Barnegat Bay, located along the eastern shore of New Jersey, was significantly impacted by Hurricane Sandy in October 2012. Scientists from the U.S. Geological...

  13. Sedimentary Data Collected in April 2016 From Old Tampa Bay, Florida (U.S. Geological Survey Field Activity Number 2016–327–FA)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The toxic dinoflagellate Pyrodinium bahamense (P. bahamense) produces recurring, persistent summer algal blooms in Old Tampa Bay, Florida, which degrade water...

  14. Sedimentary Data Collected in September 2016 From Old Tampa Bay, Florida (U.S. Geological Survey Field Activity Number 2016–350–FA)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The toxic dinoflagellate Pyrodinium bahamense (P. bahamense) produces recurring, persistent summer algal blooms in Old Tampa Bay, Florida, which degrade water...

  15. Alpha spectroscopy radioisotopic data for box core sediments collected from Barnegat Bay, New Jersey in May 2014 (U.S. Geological Survey Field Activity Number 2014-310-FA)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Barnegat Bay, located along the eastern shore of New Jersey, was significantly impacted by Hurricane Sandy in October 2012. Scientists from the U.S. Geological...

  16. Sediment Grain-size Data from sediment grab samples and box cores collected in May 2014 from Barnegat Bay, New Jersey (U.S. Geological Survey Field Activity Numbers 2014-310-FA).

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Barnegat Bay, located along the eastern shore of New Jersey, was significantly impacted by Hurricane Sandy in October 2012. Scientists from the U.S. Geological...

  17. Point Shapefile of the Interpreted Seafloor Horizon Based on Seismic-Reflection Profiles Collected in Apalachicola Bay in 2006 from U.S. Geological Survey Cruise 06001 (SEAFLOOR_GEOG.SHP, Geographic, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Apalachicola Bay and St. George Sound contain the largest oyster fishery in Florida, and the growth and distribution of the numerous oyster reefs here are the...

  18. PNG formatted images of EdgeTech 424 seismic-reflection profiles collected by the U.S. Geological Survey in Barnegat Bay, NJ in 2011, 2012, and 2013.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water quality in the Barnegat Bay-Little Egg Harbor estuary along the New Jersey coast is the focus of a multidisciplinary research project begun in 2011 by the...

  19. Bottom Photographs in JPEG format acquired using a SEABed Observation and Sampling System (SEABOSS) within Barnegat Bay New Jersey by the U.S. Geological Survey in 2012, and 2013

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water quality in the Barnegat Bay-Little Egg Harbor estuary along the New Jersey coast is the focus of a multidisciplinary research project begun in 2011 by the...

  20. 10 meter bathymetric grid of Barnegat Bay, New Jersey produced from trackline bathymetry collected by the U.S. Geological Survey in 2011, 2012, and 2013 (Esri binary grid, UTM 18N, WGS 84).

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Water quality in the Barnegat Bay-Little Egg Harbor estuary along the New Jersey coast is the focus of a multidisciplinary research project begun in 2011 by the...