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Chesapeake Bay
Blue Crab Pendants Chesapeake
Bay Estuaries are coastal ecosystems where fresh and salt water mix. The Chesapeake and others like it all over the world serve many critical ecological functions. The shorelines of estuaries are transitional areas between dry uplands and open water habitat, and support submerged aquatic vegetation (SAV) in coastal marshes. Today SAV has about 10% of its original distribution. Marshes stabilize shorelines, protecting them from erosion and trapping sediments carried into the estuary from upstream by freshwater streams and rivers. They are sites of high primary productivity, where growing plants produce biomass that feeds a great variety of animal life. Additionally, estuaries are important habitat for many adult and early life stages of marine animals, many which are of great value to commercial fisherman. Healthy estuaries are of great importance to maintaining healthy and productive fisheries. The Chesapeake Bay is Eastern North America’s largest estuary, and its watershed includes over 64,000 square miles in one of the United States most populous regions. In the mid-Atlantic United States, residential and commercial development, agriculture, and natural resource use continue to intensify environmental and ecological stresses on the Bay. The various pollutants that enter into freshwater systems throughout the watershed concentrate from a very large region into a relatively small area. And since it is very shallow for its size, the high surface area to volume ratio tends to multiply this concentrating effect of pollutants entering the Bay from upstream. Estuaries do have some inherent biological ability to absorb and process pollutants, but when this capacity is exceeded for continuous periods of time the effects can be quite destructive to their ecological balance and the health of their fisheries. Commercial fishing also influeces the ecological web of the Bay and maintaining a sustainable level of harvesting is necessary for the long term continuance of viable fisheries.
The Blue Crab
An estimated 75% of the Chesapeake’s adult blue crab population is harvested each year for human consumption. Unfortunately, crab populations have suffered recent declines and are currently at historic lows. The major cause for these declines appears to be nutrient laden runoff from the large poultry industry on the Chesapeake’s Eastern shore. Underwater grasses, an important crab habitat, have declined in response to excess nutrient runoff from the poultry industry. Since commercial crabbing has grown a lot in economic importance as the oyster industry has declined, over-harvesting is also a potential threat to the continued vitality of crab populations. Revitalization of this fishery would be a important step toward the goal of restoring and maintaining the Chesapeake’s ecological balance. Chesapeake Bay Ecology Humans
utilize and depend upon the Bay and its tributaries for sustenance, livelihood
and recreation. This interdependence makes a good case study for humans
and their relationship to the environment. In the early 1980’s the
Chesapeake Bay was in poor condition. Recognizing the need to address
a range of serious pollution and ecological problems in this vital estuary,
an interstate conservation and restoration initiative began in 1983. Called
The Chesapeake Bay Program, it was an agreement between the U.S. Environmental
Protection Agency, the District of Columbia, Maryland, Virginia, Pennsylvania
and the Chesapeake Bay Commission to cooperate in efforts to protect and
restore ecological balance to the Bay. In the year 2000, a new Bay agreement was drafted which reflects current scientific understanding of the Chesapeake as a living resource that is vital to the region. The signatories have expresses a renewed commitment to habitat protection and restoration, water quality improvements, and fisheries management. Because sound land use practices are crucial for a healthy watershed, a growing effort is underway to plant trees as vegetative buffers along streams in many Bay tributaries. Public participation in restoration projects, such as those sponsored by the Chesapeake Bay Trust, foster awareness about the need for responsible stewardship. Measurable ecological benefits of the Bay Program and allied conservation efforts are beginning to show. Increases in waterfowl population have been recorded. SAV has also increased since its historic low in 1984. Fish passages have allowed reopening of waterways to migratory fish species. There are over 50,000 acres of oyster sanctuaries. The successes during recent decades to save the Chesapeake Bay demonstrate how positive environmental benefits are achievable through proactive and informed approaches. They also remind us of how much more needs to be done to help the Bay to become the abundant natural resource it has been in the past. To find out what you can do to get involved and learn more about preservation and restoration efforts in the Bay, contact one or more of the organizations listed below. The
Chesapeake Bay Program Office Chesapeake
Bay Foundation
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