The Chesapeake Bay, the Nation's largest estuary, has been degraded due to the impact of human-population increase, which has doubled since 1950, resulting in degraded water quality, loss of habitat, and declines in populations of biological communities. Since the mid-1980s, the Chesapeake Bay Program (CBP), a multi-agency partnership which includes the Department of Interior (DOI), has worked to restore the Bay ecosystem. The U.S. Geological Survey (USGS) has the critical role of providing unbiased scientific information that is utilized to document and understand ecosystem change to help assess the effectiveness of restoration strategies in the Bay and its watershed. The USGS revised its Chesapeake Bay science plan for 2006-2011 to address the collective needs of the CBP, DOI, and USGS with a mission to provide integrated science for improved understanding and management of the Bay ecosystem. The USGS science themes for this mission are:

  Causes and consequences of land-use change;
  Impact of climate change and associated hazards;
  Factors affecting water quality and quantity;
  Ability of habitat to support fish and bird populations; and
  Synthesis and forecasting to improve ecosystem assessment, conservation, and restoration.

The USGS will use a combination of monitoring, modeling, research, and assessment to (see Science Plan Table 1 for summary)
  a. provide an improved understanding of the ecosystem to better target implementation of current conservation and restoration strategies,
  b. assess ecosystem change to help evaluate the effectiveness of management activities,
  c. forecast the potential impacts of increasing human population and climate variability, and
  d. synthesize the findings and provide implications to help policy makers and resource managers adapt improved approaches for the conservation, restoration, and ecologically sustainable development of the ecosystem. USGS scientists, located in science centers throughout the Bay watershed, work with partners to conduct investigations that are supported by multiple USGS Programs.

The The USGS is focusing the majority of its efforts to address the five science themes in the watershed (see map) because
 a. the majority of conservation and restoration activities will be implemented in the watershed,
 b. understanding the function of the different hydrologic settings and habitats in the watershed in processing nutrients and sediment will provide a more cost-effective approach to implementing management actions, and
 c. land-use change in the watershed will continue to be the greatest stress on the health of biological communities in the watershed and the Bay. The USGS is addressing the interaction of the watershed and estuary by focusing on the factors affecting water quality and habitat in the watershed and their relation to the estuary.

Regional study scales and focus areas for the USGS Chesapeake Bay studies. USGS conducts the majority of the science theme activities at regional scales in the watershed, with complementary local-scale studies in two focus areas, which include the Potomac watershed and estuary and the mid-Delmarva Peninsula. The primary regional scales are   a. the entire watershed,   b. the major drainage areas in the watershed, and   c. major landscape settings. View the map in a larger size.