USGS Chesapeake Bay Watershed Accomplishments for Fiscal Year 2015

The USGS works with Federal, State, and academic science partners to provide monitoring, research, and communication of results to enhance ecosystem management for both the Chesapeake and other National ecosystems. The Department of the Interior (DOI), through the USGS, the U.S. Fish & Wildlife Service (USUSFWS), and the National Park Service (NPS), is providing leadership, expertise, and resources to carry out the President’s Chesapeake Bay Executive Order (EO). The EO provided the foundation for the Chesapeake Watershed Agreement (2014--25), which was signed by the Chesapeake Bay Program (CBP), and includes the Federal Government, six states and the District of Columbia. The DOI has a leadership role for carrying out 7 of the 10 goals in the Agreement.

New Science Strategy will advance restoration of the Nation’s largest estuary

The USGS Chesapeake Science Strategy was prepared to guide science activities to address the Chesapeake Watershed Agreement, to support DOI involvement, and align with the USGS Mission Area (MA) Science Strategies. The USGS Chesapeake Science Strategy has four themes that address 7 of the 10 goals in the Chesapeake Bay watershed Agreement: (1) enhance science to support restoration, and conservation of fish, wildlife, and critical habitats;

(2) characterize and explain changes in water quality, and its effect on freshwater and estuarine ecosystems; (3) assess and forecast the effects of climate and land change on ecosystem conditions; and (4) synthesize and provide information to support ecosystem management. The USGS began to evolve projects and implement the strategy in 2015. Supported by the USGS Environments Program.

The effects of climate change and land use on freshwater fisheries and streams.

The USGS found that the majority of streams in the Chesapeake Bay region are warming, and that increase appears to be driven largely by rising air temperatures. Water temperature has risen, on average, 1.4 degrees Celsius (˚C) between 1960 and 2010. Upstream waters will become less suitable for some cool water fish species, such as Brook Trout, which is a key species for restoration in the Bay watershed and the eastern U.S. Another USGS study showed that groundwater is highly influential but also highly variable among streams and will lead to a patchy distribution of suitable fish habitat under climate change. This new modeling approach used Brook Trout to show that groundwater can moderate increasing stream temperatures, but can be applied to other species that require cold water streams for survival. The USUSFWS, the U.S. Environmental Protection Agency (EPA), and State partners are using the information to consider approaches to protect and manage Brook Trout and freshwater fisheries. Supported by the USGS Fisheries and Environments Programs.

Informing conservation and management of freshwater fisheries and streams.

The USGS began new studies of the potential effects of unconventional oil and gas development on Brook Trout and streams. This effort includes high-resolution (1:24,000) spatial layers of watershed attributes, Brook Trout occupancy, and disturbance signatures, biomarkers of Brook Trout response to contaminant exposure, and molecular genomics of Brook Trout populations in watersheds with unconventional oil and gas development. Another USGS study is examining the interactive effects of stream temperature and invasive species on Brook Trout behavior, physiology, and growth. Competition with Brown Trout decreased Brook Trout use of warmer streams and decreased movement rates into forage areas compared with areas with no Brown Trout. The USFWS is using the information to inform Brook Trout conservation and restoration Supported by the USGS Fisheries and Environments Programs.

Increasing the understanding of the effects of contaminants on fish and wildlife.

The USGS led development of the CBP strategy to enhance research on toxic contaminants so partners can have improved information to reduce the effects of contaminants on fish and wildlife. The USGS expanded studies on the effects and sources of endocrine-disrupting compounds (EDCs), other chemicals of emerging concern, as well as legacy compounds such as mercury, arsenic and Polychorinated Biphenyls (PCBs) on fish and wildlife in the Bay watershed. Multi-year monitoring and assessment sites have been identified to assess the biological effects of complex mixtures through bioindicators, adverse outcome pathways, and risk assessment models, and sources and pathways of exposure have also been determined. The USGS made significant progress on a database of historical information to better understand the spatial and temporal exposures to EDCs and other toxic compounds, and the land-use and climatic influences on fish health, with linkages to fish kills, fish diseases, and the lack of reproductive success occurring in Virginia, Maryland, West Virginia, and Pennsylvania. The initial results will be released in 2016. Supported by the USGS Contaminant Biology, Toxic Substances Hydrology, and Environments Programs.

Models to manage waterbirds and their habitats.

The USGS is supporting the USFWS, Maryland, and Virginia with science to restore wetlands to increase waterfowl, with a focus on Black Ducks. The USGS continued the development of models so that the USFWS can assess different options for wetland restoration on the Bay refuges. USGS reported their findings on the availability of quality prey items for wintering surf scoters in the Bay. They continue to calculate the index of biological integrity to classify the Bay’s shoreline types for waterbird use. The USGS began a new study to predict future impacts of sea-level rise on coastal wetlands, which provide habitat for almost 1 million waterfowl wintering in the Bay region. Supported by the USGS Environments, Wildlife, and Climate Research and Development Programs.

Understanding the decline of wintering surf scoters in Chesapeake Bay

The decline in surf scoter, and important waterfowl populations wintering in the Chesapeake Bay, has been associated with changes in the benthic bivalves which are their primary food source. The hooked mussel was one of the primary prey items for surf scoters but is less common now, causing the surf scoter to switch to a more opportune species, the dwarf surf clam. The USGS studied the composition (macronutrients, minerals, and amino acids), shell strength, and metabolizable energy of these prey items and found no difference in metabolized energy between these two main food sources. Therefore, wintering surf scoters were able to obtain the same amount of energy from each prey item, implying that they can sustain themselves while wintering in the Chesapeake Bay. The information is being used by the Atlantic Coast Joint Venture to inform restoration decisions along the East Coast. Supported by the USGS Wildlife and Environments Programs.

Informing decisions to improve water quality.

The USGS leads the monitoring of nutrients and sediment in the nontidal parts of the Bay watershed and is working to explain water-quality changes throughout the entire watershed. The water-quality results are being used by the six States in the watershed and EPA to revise plans to meet the Chesapeake Bay Total Maximum Daily Load (TMDL) and its 2017 Midpoint Assessment. USGS released a report on water-quality conditions on the Eastern Shore and the relation to manure and fertilizer applications. The results helped inform the Maryland General Assembly on legislation to reduce the application of manure in areas where the soils contain high amounts of phosphorus. The USGS also enhanced its statistical tool Weighted Regressions on Time, Discharge, and Season (WRTDS) to quantify the uncertainty in estimates of water-quality trends and offers various ways to visualize and communicate these uncertainties. The USGS used WRDTS to update trends throughout the watershed and help to explain water-quality changes to inform the TMDL. Supported by the USGS Environments and National Water-Quality Assessment (NAWQA) Programs.

Improved land cover information and forecasting to inform conservation.

The USGS collaborated with CBP partners to improve land-cover classifications for the 64,000- square-mile drainage basin that touches six States and the District of Columbia. The USGS worked with the Chesapeake Conservancy on new approaches, including the use of LiDAR, to develop high-resolution information for land classifications. The improved land-cover data are a critical piece of information needed to revise the CBP watershed model that is used for TMDL decision making. The USGS also revised a land-change model that uses historical information to provide scenarios of future development in the Bay watershed. The forecasts will be used by NPS and non-governmental organizations to assess the vulnerability of healthy watersheds and inform land conservation efforts, including those funded by the DOI Land and Water Conservation Fund. Supported by the Land Change Science and Environments Programs.