Living Resources of the Chesapeake Bay

In recent years, the Chesapeake Bay has become even less able to support the fish and wildlife it once did. Increasing amounts of nutrients, sediments, and toxic substances are causing serious ecological problems. Studies show alarming declines in populations of fish and wildlife and in the habitat available to them.

The Chesapeake Bay Executive Order, signed in May 2009, provides FWS a unique opportunity to take action by applying political and public will coupled with advanced technology and innovative science to address these detrimental impacts. Toward this end, FWS will focus its actions to raise the bar for habitat protection and restoration across all regions of the Chesapeake Bay watershed for the betterment of living resources. Our three objectives call for application of science and technologies to improve management decisions for habitats and living resources and the communities that depend on them, including 1) prioritizing actions that maximize ecological benefits for priority species, 2) accelerate habitat protection and restoration, and 3) better coordinate research and assessment across the watershed.

FWS Work in the Bay - Summary Data


Poor Water Quality

Poor water quality alters available habitat and can limit the success of restoration efforts. Oxygen-deprived water is considered to be the largest aquatic pollution problem in the United States and is associated with increased harmful algal blooms and large areas of “dead zones” in the Chesapeake Bay. It also causes the loss of submerged aquatic vegetation, an important habitat for a variety of species. Excess nutrients imported into the Chesapeake watershed may limit the ability to address habitat issues and are an overarching concern.

Invasive Species

Invasive species are animals and plants not native to the watershed that spread throughout the area quickly, often overtaking native species. There are more than 200 invasive species in the watershed; some, like nutria, northern snakehead, zebra mussels, phragmites, purple loosestrife and water chestnut, cause costly ecological problems. Some invasive species can take over entire habitats while others consume the food or alter the habitat needed by our native species. For example, upland invasive plants, such as garlic mustard, tree of heaven and Japanese honeysuckle, reduce the stability of soil, which leads to increased sediment entering streams throughout the watershed.


Evidence collected in the Piedmont Province of the Potomac River suggests that the presence of endocrine-disrupting chemicals is affecting immune systems in fish and may be related to a high occurrence of intersex, or the presence of immature eggs in male fish, in smallmouth bass. Intersex is an indicator of chemical contamination. Loss of habitat can affect transport of contaminants. Human consumption advisories are in place for more than a dozen fish species in Maryland, Virginia and other states’ waters due to PCBs, mercury and pesticides in the fish.

Habitat Loss

Living resources depend on networks of healthy and connected habitats for food, water, shelter and breeding areas. Land use changes fragment or destroy these natural places and can affect others downstream, leaving fewer natural habitats available to provide plants and animals with the basics they need to live. For instance, development can create more impervious surfaces, leading to increased soil and pollutant runoff into the Chesapeake Bay.

Disease and Pathogens

Impacts of other stressors can result in increased disease outbreaks, high parasite loads, and decreased disease resistance. For instance, mycobacteriosis is a chronic bacterial disease currently affecting Chesapeake Bay striped bass, causing loss of fish and economic impact for recreational and commercial fisheries. Some of the mycobacteria that commonly infect fishes can also cause infections in people. Diseases have decimated native oysters and, additionally, the habitat and water quality benefits they provide. Scientists predict that disease issues will become more prominent in response to higher water temperatures caused by climate change.


Manage and Protect Habitats

Within the watershed, the U.S. Fish & Wildlife Service manages and protects a variety of vital habitats for living resources. On the Service’s lands - national wildlife refuges – habitat management regimes are designed and implemented specifically for the Chesapeake Bay’s living resources and their unique needs. Regimes implemented for migratory birds, for example, include the management of marshes and impoundments to produce food sources and freshwater habitats. Grassland-nesting birds, as well as other species, benefit from mowing and/or prescribed habitat burning that provides several stages of grassland growth.

Restore and Enhance Habitats

Shorebirds, neotropical migratory songbirds, raptors and marsh birds rely heavily on the Chesapeake Bay and its tributaries for vital nesting, breeding and overwintering habitats during the spring and fall migration periods. Within the Service, the Partners for Fish and Wildlife Program and the National Wildlife Refuge System, with help from partners and volunteers, are working to restore and enhance a variety of these habitats – including wetlands, native grasslands and riparian forests - to provide for the species that depend on them.

Remove Invasive Species

The Service is focused on managing invasive species to improve or stabilize living resource habitats and communities and preventing new or expanded infestations of invasive species. Within the Service, habitat management activities on National Wildlife Refuge System lands prevent, control or eradicate invasive species using techniques in integrated pest management plans that comprehensively evaluate potential integrated management options, including defining threshold or risk levels that will initiate the implementation of proposed management actions.

Assess and Remediate Contaminants

The U.S. Fish & Wildlife Service is the primary federal agency dedicated to protecting the Chesapeake Bay’s natural living resources from the harmful effects of contaminants, toxic substances that can harm people, fish, wildlife and plants. The mission of the Service’s Environmental Contaminants program is focused on identifying and preventing harmful contaminant effects on fish and wildlife, and restoring resources degraded by contaminants.

Study Disease and Pathogens

Within the Chesapeake Bay watershed, disease and pathogens threaten living resource populations. The Service’s Lamar Fish Health Center is one key component of the disease and pathogen work performed for living resources in the watershed. The center provides critical diagnostic and screening services to the Service and partner organizations. It also develops disease prevention and containment guidelines for use throughout the Northeast Region, including the Chesapeake Bay.