December, 2000

There are many current threats to the Chesapeake Bay ecosystem.  For example, over-harvesting of animals, such as oysters and crabs, endangers their survival in the future (Basin Wide Info On-line Service Project, 2000).  Also, an excess of nutrients impair the quality of the Bay.  Too many of these nutrients can cause algal blooms, dense clusters of phytoplankton, which cut off oxygen to the bay’s bottom, endangering the bottom-dwellers.  Increased sediments also pose a problem for the wildlife in the Bay, by deteriorating their tissues.  Agricultural and urban storm water run-off significantly increases the amount of sediments, nutrients, and pesticides in the Bay.  Moreover, erosion washes away some of the shoreline, thus carrying more sediment into the Bay.  The depth of erosion resulting from tides measures .1 to 1 millimeter thick in the mid-bay area (Chesapeake Executive Council, 2000).  Another concern in the Bay is the decrease in underwater bay grasses, or subaquatic vegetation, which play a pivotal role in the ecosystem.  The grasses improve the water quality by absorbing nutrients and catching sediments.  So a decrease in the amount of underwater grasses damages the bay as a whole, yet the grasses are also dependent upon water quality.   A mere ten percent of streams in Maryland are still in good condition (Huslin "Survey," 2000).  Therefore, increasing sediments and nutrients, erosion, over-harvesting of animals, and a decrease in underwater grasses threaten the health of the Chesapeake Bay.

Many individuals and industry contribute in some way to damaging the Bay.  For example, chemicals used in agricultural fertilizer and for sewage treatment contain phosphorous and nitrogen, an abundance of which can harm the Bay.  Run-off from farms can transport these nutrients into surface or groundwater.  A population increase can result in more urban sewage treatment plants or fertilizer use, thus leading to more pollutants in the Bay (USGS Ecosystem, 2000).  Industry also generates much of the waste that contaminates the Bay.  Wastewater, which contains nutrients, from factories can detrimentally affect the Bay.  One cause of environmental degradation of streams is removing trees and vegetation in order to build roads and sidewalks (Huslin "Survey," 2000).  As a result, run-off enters into streams more quickly.  In addition, waterways are more susceptible to damaging run-off when land is cleared for developmental purposes.  This has been an especially prevalent problem over the past 50 years (Leffler, 2000).  Thus, population increases, industry, and development are the origins of some of the environmental problems plaguing the bay.

The Chesapeake Bay serves the surrounding area, and the nation, in many different ways.  The Bay serves as a habitat for various animals and plants, and produces millions of pounds of seafood every year (Basin Wide Info On-line Service Project, 2000).  If poor water quality leads to the death of too many fish and crabs, the seafood industry might suffer.  Furthermore, the Bay serves a recreational purpose for visitors, as well as local inhabitants.  Moreover, water from the bay goes to help with industrial processes and cooling procedures.  Most of the land in the Chesapeake Bay area is forestland, or used for agricultural purposes (United States Army Corps of Engineers, 1984).  There has been a steady increase in urbanized land over the past 50 years (Heck, 1987).  As a result of this urbanization, water quality has decreased, at least between 1950 and 1980, because of increases in nitrogen and phosphorous (Heck, 1987).  The Bay serves many functions for its watershed inhabitants and the nation, and its deterioration can affect many.  It is vital that transportation, water, and sewer systems are planned in such a way to prevent contamination of the Bay.

How Nutrients Harm the Bay 

While elements such as nitrogen and phosphorous are vital for biological processes, when they are present in large quantities, they can actually damage the ecosystem (Basin Wide Info On-line Service Project, 2000).  In Maryland, more than half of the freshwater streams have some form of pollution from nutrients (Huslin "Survey," 2000).  Oxygen, for example, is crucial for the animals in the Bay, and when temperature and salinity cause a decrease in the oxygen, the wildlife can suffer.  Carbon dioxide, also fundamental to plants, is affected by temperature and salinity in much the same way.  These nutrients can enter the bay in the form of run-off from sewage treatment plants, industries, exhaust, acid rain, agricultural, and urban areas (Basin Wide On-line Service Project, 2000).  The excess nutrients lead to phytoplankton overgrowth, algal blooms, which become dense enough to cut off sunlight from underwater plants.  Furthermore, oxygen is used during the decay of the blooms, sometimes resulting in an insufficient level of oxygen in the water that might kill various wildlife or plants.  Sewage contributes 25% of the nitrogen contaminating the Bay.  One method used to decrease amounts of nitrogen in the Bay is sewage treatment and denitrification of wastewater.  This method is also relatively inexpensive.   Denitrification is used in 43 treatment plants in the bay area and in the next five years, it is estimated that 58 more will be established (Schmiedeskamp, 1998).  Various denitrification programs have cut the amount of nitrogen going into the Bay by half.  The goal is a nutrient reduction of 40% by this method (Schmiedeskamp, 1998).  One study of nutrient management procedures, showed a 62% decrease of nitrogen, and a 61% decrease in phosphorous over a two-year period (United States Geological Survey, 1995). 

Reduction of total fertilizer applied to fields serves as another solution to the excess nutrient problem.  One can also strive to prevent the fertilizer from washing away into the Bay or its tributaries.  To accomplish this, wetlands or forests can serve as a buffer, or another place for the nutrients to go.  Another method of nutrient removal is upgrade to wastewater treatment plants, which implements technology to remove nutrients.  Approximately, 1.5 million acres are under some form of nutrient management (Schmiedeskamp, 1998).  Also, a ban on phosphate detergents can aid in nutrient reduction.  In addition, nutrients can come from atmospheric deposition, precipitation or dry deposition, and groundwater discharge.  Nonpoint source pollution, like that in the Chesapeake Bay, is distributed throughout the water source and includes precipitation, run-off, and ground water discharge (Belval and Sprague, 1999).  Therefore, there are many possible solutions to the problem of excess nutrients in the bay.

Besides the nutrient problem, suspended sediments also pose a problem to the Bay by transporting nutrients and decreasing the amount of water clarity.  When too much sediment accumulates around a port, it can fill up enough to become landlocked.  Furthermore, when sediments collect on the Bay’s bottom, plants and wildlife can be smothered to death. Toxic materials can be contained within the sediments and infect animals and plants. Some of the most abundant sediments found in the Bay include copper, mercury, and atrazine.  In general, differing salinity affects how contaminants will be transported through the waterway.  Waves, wind currents, tides, and various natural disasters also affect how and if sediments will settle to the bottom of the Chesapeake.  Oxygen levels can also have an effect on the sediments, since oxygen causes the release of copper, zinc, and other metals.  Also, organisms can influence the sediments.  Depending on their metabolisms, the contaminant can either become more or less toxic as a result of passing through the organism.  Thus, sediments can adversely affect the water quality of the Chesapeake Bay.

The current condition of the Bay threatens the organisms in the ecosystem.  The Bay provides many different habitats for 2700 migratory and resident species (Basin Wide Info On-line Project, 2000).  For example, different animals live in shallow waters than those who inhabit the wetlands.  One of the most abundant aquatic organisms is phytoplankton, free- floating plants.  The phytoplankton can assist in transporting contaminants.  Many birds also inhabit the bay, such as sparrows, waterfowls, marsh hawks, herons, etc.  In addition, the bald eagle nests in the bay area.  Some fish that can be found in the Bay include striped bass, weakfish, shad, herring, and croaker (United States Army Corps of Engineers, 1984).  As a result of Bay contamination, some fish contain lethal amounts of mercury.  A fish or oyster can become contaminated either by direct contact with the chemical or by eating polluted phytoplankton.  Certain chemicals can cause significant changes in the organisms.  For example, trace amounts of arsenic have been observed to cause cancer lesions on some fish.  Arsenic can also cause a trend of smaller phytoplankton species. 

Recently, efforts have been made to try to increase the oyster population in the Bay.  Congress approved a recovery project to rebuild oyster reefs, since the poor health of the Bay has led to a decrease in their abundance.  Oysters also serve a major purpose in the Bay by filtering out impurities and phytoplankton (Huslin "Congress," 2000).  Blue crabs have also been adversely affected by the Bay’s current condition.  The Bay supplies half of the U.S.’s total blue crab harvest (USGS Ecosystem, 2000).  The population of blue crabs is put in jeopardy because they dwell in subaquatic vegetation, which does not grow as much in a contaminated waterway.  The Chesapeake Bay 2000 Agreement calls for the establishment of harvest targets for blue crabs and the beginning of state managed fisheries for them.  Overharvesting, degradation of habitat, and disease are responsible for the decrease in oyster and blue crab populations.  Pot limits, gear restrictions, and license restrictions serve to increase regulate the control of blue crabs.  Restoration efforts aim to improve the condition of wildlife surrounding the Bay through harvest level managing and water quality control.  Thus, wildlife has been adversely affected by the conditions of the Chesapeake Bay.

Various congressional acts have been passed to allow for restoration efforts of the Bay.  For example, Chesapeake Bay Agreements were signed in 1987, 1992, and 2000.  In the 1987 Chesapeake Bay Agreement, the goal was to decrease nitrogen and phosphorous going into the bay by 40% by 2000 (Basin Wide Info On-line Service Project, 2000).  In the 1992 amendment to this act, this goal was maintained, and a watershed-wide nutrient reduction program was implemented for the Bay’s ten major tributaries (Basin Wide Info On-line Service Project, 2000).  Then in 1993, another amendment allowed for the increase in underwater bay grasses to 114,000 acres by 2005, increase in rockfish, and point source pollution reduction (Basin Wide Info On-line Service Project, 2000).  Also a resource management program was put into effect for agriculture.  Another law that helped the bay was the Critical Areas Law restricting cutting down trees near shorelines to reduce sediment and nutrient run-off. 

Finally, the 2000 Chesapeake Bay Agreement allows for much restoration of the Bay.  For example, the Chesapeake Bay Program will provide for maintaining good water quality conditions and restoring the various habitats of the Bay (Chesapeake Bay Program Chesapeake 2000, 2000).  It also provides that the Bay improve enough to be removed from the Clean Water Act’s impaired waters list in the near future (Chesapeake Bay Program Chesapeake 2000, 2000).  Furthermore, pollution will be prevented, sediments reduced, and freshwater flow will be protected (Chesapeake Bay Program Chesapeake 2000, 2000).  Also, the act encourages the entire watershed to cooperate for a better Bay.  Therefore, various acts of legislation have provided for increased attempts at improving the current state of the Bay. 

Many attempts have been made to rectify the condition of the Bay.  The Bay was the U.S.’s first estuary benefiting from any form of restoration or protection.  First, in 1983 and 1987, the Chesapeake Bay Program was created to restore the Bay to good health.  It helps carry out the provisions referred to in the various legislation passed concerning the Bay.  Also, on a more local level, the Maryland Department of Natural Resources plays a pivotal role in improving the condition of the Chesapeake watershed.  The department collects data 14 times a year from 22 stations located throughout Maryland (Maryland Department of Natural Resources, 2000).  They measure water temperature, dissolved oxygen, salinity, and water clarity.  The Maryland DNR also established the Chesapeake Bay Monitoring Program to measure pollutants, water quality, and wildlife.  Also, the DNR has built drainage ditches to collect storm water run-off.  The DNR plans on conducting a survey once every five years to check the quality of Maryland streams affected by the bay. 

Since human intervention is the root of much of the Bay’s environmental concerns, improvements cannot come without the help of many.  Inhabitants of the watershed area can take many steps to encourage restoration of the Bay.  For example, conservation of water decreases the amount of water treated and discarded into the Bay.  Also, one can begin a compost pile to reduce nutrients and decrease the amount of toxic materials around the household.  By carpooling and driving less, one can decrease the pollution into the Bay.  Furthermore, individuals can divert run-off to vegetated, instead of paved, locations.  By studying the Bay’s sediments and microfossils, the United States Geological Survey has monitored the conditions in the Bay since 1950.  Various programs try to correct the bay’s environmental problems, and definite success has been made, especially in regard to the 1987 Agreement’s 40% nutrient reduction goal (Belval and Sprague, 2000).  As a result of restoration efforts, subaquatic vegetation has increased. 

Best management practices (BMP’s) have also been used to solve the problem of surface nutrient run-off.   The conditions of the area greatly affect how BMP’s will help with the increased nutrient problem.  Some structural BMP’s consist of terracing, and fencing, whereas a nonstructural one might be tillage and strip filters.  BMP’s can affect soil, hydrology, and mode of transport (Park, Mostaghimi, and Cooke, 1994).  The Chesapeake Bay Program has already implemented some BMP’s in an attempt to remove nutrients, however, it is a difficult system to monitor because it takes a long time for the nutrients to go from the groundwater to the stream.  Thus, many steps have been taken to remedy the current environmental problems facing the Bay.

The Chesapeake Bay is a valuable resource to nearby inhabitants and the nation.  However, its current state does not bode well for the future.  Excess nutrients, sediments, and erosion are just some of the problems that threaten the Bay’s health and ecosystem.  These problems result from farm and urban storm-water run-off, and industrial and sewage treatment water waste.   By affecting the water, these outside threats have indirectly influenced the survival rate of animals and plants along with the lives of many who depend upon the Bay for seafood, shipping, etc.  If restoration plans do not significantly improve the state of the Bay, the entire ecosystem will feel the effects of environmental degradation.  And so, only with cooperation can the Bay truly improve.  The Chesapeake Bay watershed population is only predicted to increase, causing a strain on the endangered resource.  Proper restoration techniques and cooperation must continue to correct the environmental damage done to the Chesapeake Bay. 

Works Cited

Belval, Donna L. and Sprague, Lori A.  United States Geological Survey.  "Monitoring Nutrients in the Major Rivers Draining in the Chesapeake Bay." Washington D.C.: November 1999.

Heck, Kenneth L.  Ecological Studies in the Middle Reach of Chesapeake Bay.  Berlin: Springer-Verlag, 1987.

Huslin, Anita.  "Congress Approves Oyster Funding."  The Washington Post October 21, 2000: pB4.

Huslin, Anita.  "Survey Finds MD. Streams in Poor Health; Watershed Damage from Development and Pollution Widespread, Report Says."  The Washington Post September 25, 2000: pBO2

Leffler, Merrill.  "Restoring Bay Grasses to the Chesapeake: A Long Way Back."  Maryland Marine Notes May-August 2000: 3-4.

Lippson, Alice J. and Robert L., Life in the Chesapeake Bay.  Baltimore: Johns Hopkins University Press, 1997.

Park, S.W., Mostaghimi, S., Cooke, R.A., McClellan, P.W.  "BMP Impacts on Watershed Runoff, Sediment, and Nutrient Yields."  Water Resources Bulletin vol. 30 no. 6 (1994): 1011-1023.

Schmiedeskamp, Mia.  "Getting the Nutrients Out."  Scientific American August 1998: 34-37. 

United States Army Corps of Engineers.  "Chesapeake Bay Study."  Baltimore: September 1984.

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