Chesapeake Bay an Undeclared Ecological Disaster
written by James Price / Published in Bay Journal April 2001
Fifty years ago the Chesapeake Bay was one of the most beautiful and productive estuaries on our planet. Water quality was good and extensive grass beds were an integral part of the Bay's ecology. The aquatic vegetation provided habitat and sanctuary for many species of marine life, and was a primary source of food for wintering waterfowl. The vegetation helped stabilize the Bay's bottom, improved water clarity, and increased the estuaries' dissolved oxygen. Oysters were an important part of the Bay ecosystem; their reefs provided habitat for a wide variety of marine life, and they filtered a large amount of nutrients which helped improve water quality. Waterfowl, finfish, shellfish, and the blue crab were all relatively abundant throughout the Chesapeake Bay at the middle of the 20th century.
Over the past half century most of the aquatic vegetation disappeared. The waterfowl that fed primarily on the Bay's underwater grasses and couldn't adapt to feeding on the land now fly over the Chesapeake Bay to winter further south. The Bay's common loon population has been reduced approximately 90% following almost a decade of poor recruitment of juvenile Atlantic menhaden, it's primary food source. Declining water quality has stressed the Bay's living resources and fish kills are becoming more frequent throughout most of the Bay. There are warning signs that indicate the bottom of the food chain has been affected by pollution. The number of ecologically less desirable species of phytoplankton (algae) such as bluegreen algae and potentially toxic dinoflagellates (e.g. Pfiesteria) is increasing. Bacteria levels in the Bay are among the highest known to exist in any estuarine environment. Zooplankton, the food base for many fish species, are declining throughout the main stem of the Bay during the summer growing season, similar declines have also been documented during early spring and fall in the lower Bay. In contrast, comb jellyfish, an important predator of zooplankton and fish larvae, has dramatically increased in the mid-Bay. The numbers of harmful algae blooms that are potentially harmful to humans, and have been proven lethal to aquatic life, are increasing in the Bay. These blooms also lower the Bay's dissolved oxygen and block sunlight preventing underwater grasses from growing.
The Chesapeake's commercial fisheries are but a remnant of what they were fifty years ago, even the forage fish are at historically low densities. Data collected from 1985 to 1999 by the Chesapeake Bay Program (CBP) indicate that blue crab larvae entering the Chesapeake Bay from our coastal waters have declined approximately 70% at the mouth of the Bay. Shellfish populations are only a fraction of their historic levels because of over harvesting, loss of habitat, pollution, and disease, and now one of the Bay's top predators, the striped bass, has been diagnosed with a disease that may significantly reduce its population.
Our elected officials and government agencies have failed to adequately regulate pollution entering the Chesapeake Bay. The coal fired power plants located in the Tennessee and Ohio valleys raised their smokestacks during the 1960's, sending their pollution eastward to the Chesapeake Bay region. Atmospheric pollution from ammonia emissions related to agriculture, power plants closer to the Bay, auto emissions, and other fossil fuel combustion combined to create a major insult to the integrity of the Chesapeake's fragile ecosystem.
Extensive land development along the Susquehanna River and other areas of the Bay's watershed has resulted in increased loads of nutrients and sedimentation flowing into the Bay. Pollution entering the Bay from multiple sources including agricultural runoff, and waste treatment plants caused health officials to close thousands of acres of shellfish beds. The poultry industry has grown on the Delmarva peninsula and has become an additional threat to the Bay's water quality because of the excessive amount of manure that is being inadequately stored and spread on the land. An outbreak of Pfiesteria in 1997 was attributed to the nutrient enrichment of several tributaries that enter the Bay from Maryland's Eastern Shore, a region of the Bay's watershed, where the spreading of poultry manure on farmland has been the accepted practice for years.
The Chesapeake Bay was placed on the Environmental Protection Agency's (EPA) list of "impaired' waters in 1999. The year 2000 left no doubt that the Chesapeake bay was an ecological disaster, water quality was so poor in some major tributaries that record low dissolved oxygen levels were recorded during the summer, following one of the most widespread mahogany tides ever observed in the Bay. There were numerous documented fish kills throughout many parts of the Bay. Recent striped bass health studies conducted by the Maryland Department Of Natural Resources indicate that approximately 50% of the Bay's striped bass population is suffering from a slow growing progressive disease linked to mycobacteria, which causes an infection that attacks the internal vital organs of the fish. The 2000 blue crab harvest was the lowest on record, forcing many watermen out of business by the middle of the summer. The EPA said it could require a mandatory clean-up plan known as Total Maximum Daily Load unless the Bay attains water quality standards that support the needs of it's marine life by 2010.
The Chesapeake Bay Program was created in 1983, to organize a clean-up effort in the Bay; it consists of a partnership among Maryland, Pennsylvania, Virginia, the District of Columbia, the Environmental Protection Agency, and the Chesapeake Bay Commission. The 1987 Chesapeake Bay Agreement stated that its top priority was to provide for the restoration and protection of the Bay's living resources, their habitats, and ecological relationships. Ironically, no Ecological Management Plan has ever been developed by the CBP, and no comprehensive ecological assessment for the state of the Bay has ever been conducted. An annual ecological assessment should be made available to the public in accordance with the framework established in an Ecological Management Plan. The plan should include biological indicators, for example the Bay's fisheries, submerged aquatic vegetation, and forage fish, which could be used to assess whether the Bay is responding to the many initiatives developed by the CBP to improve water quality. An Ecological Management Plan needs to encompass the Chesapeake Bay and adjacent Atlantic coastal waters, because our coastal waters are critical habitat during the early life stages for some of the Bay's important fisheries. However, the CBP does not monitor our coastal waters, therefore, it is uncertain whether good year classes of several species, including Atlantic menhaden, spot and blue crab, are determined offshore before they enter the Chesapeake Bay. This creates a dilemma for scientists and fishery managers who are struggling to develop management plans for these declining fisheries.
The CBP has adopted individual Fishery Management Plans for some of the Bay's fisheries; unfortunately, this has not resulted in successful fisheries management and doesn't focus on maintaining an ecological balance in the Bay. The 1987 Chesapeake Bay Agreement stated that fishery management plans are needed for the Bay's most valuable ecological and commercial species, however no fishery management plan has been developed for Atlantic menhaden. The Atlantic menhaden is the most abundant species of finfish commercially harvested in the Chesapeake Bay and their harvest supports one of the largest commercial fisheries in the United States. Atlantic menhaden are an important filter feeder, transferring enormous amounts of nutrients into forage biomass, and at the same time improving water quality with the potential to consume up to 25% of the Bay's nitrogen. The CBP needs to work with Virginia and Maryland officials to develop an Atlantic Menhaden Fishery Management Plan for the Chesapeake Bay because of the importance this resource has to the ecology and the restoration of the Chesapeake Bay.
The Atlantic States Marine Fisheries Commission (ASMFC) was established in 1942 and is comprised of 15 coastal states from Maine to Florida and it's main objective is to promote, protect, and conserve shared marine fishery resources along the Atlantic coast. Fishery Management Plans are routinely approved by the ASMFC without considering the health of individual species, or their effect on entire ecosystems along the Atlantic coast. For example, the ASMFC didn't consider the ecological impact of setting a harvest quota or raising the minimum size limit on the health of the Bay's striped bass population. The ASMFC doesn't attempt to coordinate their Fishery Management Plans for the Atlantic coast with Fishery Management Plans adopted by the CBP for the Chesapeake Bay. This failure in fisheries management is exemplified by the current unhealthy condition of the Bay's striped bass population and how it has been adversely affected by the Bay's declining forage base. A report titled "A Bioenergetics Approach For Determining The Effect Of Increased Striped Bass Population On Its Prey And Health In The Chesapeake Bay" can be found on the Chesapeake Bay Ecological Foundation's website at www.chesbay.org. Recently the ASMFC amended their Atlantic Menhaden Fishery Management Plan; however, they did not address the plan's ecological objectives, one of their primary concerns over allocation of the stock. The ASMFC should be required to review a Chesapeake Bay Ecological Management Plan drafted by the CBP before developing new or amending existing Fishery Management Plans that could have a negative impact on the ecology of the nation's largest estuary.
A successful effort to reduce pollution entering the Bay and surrounding ocean waters can help create favorable environmental conditions for the restoration of the Chesapeake Bay, however fishery managers need more education in the field of ecology so they can manage our fisheries based on science not politics. The public would be more interested and willing to support the restoration effort by the Chesapeake Bay Program if we had an Ecological Management Plan that focused on the management of the Bay's living resources.