Agricultural Run-off in the Chesapeake Bay
History
General Information
The Chesapeake Bay watershed is 64,000 square miles and has 11,600 miles of tidal shoreline, including tidal wetlands and islands.
The watershed encompasses parts of six states. Approximately 17 million people live in the watershed; about 10 million people live along its shores or near them.
Formed about 12,000 years ago as glaciers melted and flooded the Susquehanna River valley, the Chesapeake Bay is North America's largest estuary and the world's third largest. Chesapeake Bay is approximately 200 miles long and runs north-south from the mouth of the Susquehanna River to the Atlantic Ocean. Chesapeake Bay's headwaters begin at Cooperstown, N.Y., home to the Baseball Hall of Fame. More than 500 million pounds of seafood is harvested from the Bay every year. The Bay supports 3,600 species of plant and animal life, including more than 300 fish species and 2,700 plant types. <ref> Bay Area Facts. Chesapeake Bay Foundation. <http://www.cbf.org/Page.aspx?pid=433></ref>
Health of Chesapeake Bay
According to the CBF's 2008 State of the Bay Report the Bay's health rates a 28 out of 100 (a "pristine" Bay circa. 1600). At its worst in the early 1980s, the Bay would have scored a 23. A "saved Bay" would score a 70 (CBF: Chesapeake Bay Foundation).
The leading threat to the health of the Chesapeake Bay is excess nitrogen and phosphorus pollution that destroys habitat and causes fish kills. Top sources of these pollutants include agriculture, sewage treatment plants, runoff from urban and suburban areas, and air pollution from automobiles, factories, and power plants. Other threats to the Bay's health include sprawl, toxic pollution, and poor fishery management. Since colonial times, the Bay has lost half of its forested shorelines, over half of its wetlands, nearly 90 percent of its underwater grasses, and more than 98 percent of its oysters. During the 350 years between 1600 and 1950, approximately 1.7 million acres of the Bay watershed were developed. During the 30 years between 1950 and 1980, the Bay watershed lost an additional 2.7 million acres to development. The landmark Chesapeake Bay Agreement (a voluntary pledge to Save the Bay signed by the governors of Maryland, Virginia, and Pennsylvania as well as the administrator of the Environmental Protection Agency and the mayor of Washington, D.C.) serves as the blueprint for restoring the Bay's health. <ref> Bay Area Facts. Chesapeake Bay Foundation. <http://www.cbf.org/Page.aspx?pid=433></ref>
Geography
On average, the Chesapeake holds more than 15 trillion gallons of water. Although the Bay’s length and width are dramatic, the average depth is only about 21 feet. The Bay is shaped like a shallow tray, except for a few deep troughs believed to be remnants of the ancient Susquehanna River.
The troughs form a deep channel along much of the length of the Bay. The channel allows passage of large commercial vessels. Because it is so shallow, the Chesapeake is far more sensitive to temperature changes and wind than the open ocean. <ref> Geography. Chesapeake Bay Foundation. <http://www.cbf.org/Page.aspx?pid=683></ref>
Habitat
The Chesapeake Bay provides food, water, cover, and nesting or nursery areas to more than 3,000 migratory and resident wildlife species. Habitat types range from hardwood forests of the Appalachian mountains to saltwater marshes in the Bay. These habitats are influenced by climate, soils, water, plant and animal interactions, and human activities. <ref> Habitat. Chesapeake Bay Foundation. <http://www.cbf.org/Page.aspx?pid=684></ref>
Plants
Underwater grasses like wetlands, underwater grasses (known as submerged aquatic vegetation or SAV) serve as habitat for aquatic animals, and as a food source for waterfowl. And like other Bay grasses, they produce much-needed oxygen. But perhaps their most constructive feature is their ability to trap sediment that can cloud the water. As waves roll into grass beds, the movement is slowed and energy is dispelled, protecting shorelines from erosion. During the growing season, Bay grasses take up and retain nitrogen and phosphorus, removing excess levels that could fuel unwanted growth or algae.
Survival of Bay grasses is affected by the amount of light that reaches the plants. Poor water quality resulting in less light penetration is the primary cause for declining grasses. Algal blooms, as a result of too much nitrogen and phosphorus, also cloud the water and reduce sunlight to SAV. The absence of SAV translates into a loss of food for many Chesapeake Bay species, but bay grasses have rebounded steadily since their lowest point in 1984. <ref> Plants. Chesapeake Bay Foundation. <http://www.cbf.org/Page.aspx?pid=612></ref>
Animals
Probably the best-known animal in the Bay watershed is the famous blue crab, but many other species call this watershed home. The Chesapeake Bay provides food, water, cover, and nesting or nursery areas to more than 3,000 migratory and resident wildlife species. <ref> Animals. Chesapeake Bay Foundation. <http://www.cbf.org/Page.aspx?pid=613></ref>
Crabs and Oysters
Crabs and oysters are famous Bay residents, but sadly their numbers are alarmingly low. From the 1950s to the 1970s, the average annual oyster catch was about 25 million pounds per year, and the blue crab harvest contributed nearly a third of the nation’s catch. Today, the Bay’s oyster population is a mere two percent of its historic level, and reduced amounts of underwater grass habitat, in addition to low summer levels of dissolved oxygen, continue to keep the crab population well-below the average. <ref> Crabs and Oysters. Chesapeake Bay Foundation. <http://www.cbf.org/Page.aspx?pid=613></ref>
Water Quality
The Chesapeake Bay and its rivers and streams are in critical condition. They suffer from an overload of pollution from many different sources. Nitrogen and phosphorus pollution are the most serious problems facing the Bay. Too much nitrogen and phosphorus cause algae blooms that block sunlight to underwater grasses. When the blooms decompose, they consume oxygen and create “dead zones,” where dissolved oxygen levels are too low to sustain marine life. <ref> Water Quality. Chesapeake Bay Foundation. <http://www.cbf.org/Page.aspx?pid=495></ref>
Excess nitrogen and phosphorus from many human activities degrade our water quality. One major source of excess nitrogen and phosphorus is:
Agriculture
Farming and a healthy farm economy play a critical role in local communities. Preserving farms and open space is essential, because these lands serve as precious natural filters for our water.
But agricultural lands also contribute nitrogen, phosphorus, and sediment pollution to our rivers and streams. Agricultural measures such as limiting polluting runoff: stream buffers, cover crops, rotational grazing, and other “best management practices” are the most cost-effective way to reduce nitrogen and phosphorus pollution to the Bay. In fact, scientists estimate that we could achieve almost two-thirds of the nitrogen and phosphorus reductions necessary to restore the Chesapeake Bay, at only 13 percent of the total cost of Bay restoration, by implementing them.
Other sources by human activities include sewage, stormwater, air pollution etc. <ref> Agriculture. Chesapeake Bay Foundation. <http://www.cbf.org/Page.aspx?pid=506></ref>
Algal Blooms
What is Eutrophication?
“Eutrophication is the enrichment of an ecosystem with chemical nutrients, typically compounds containing nitrogen, phosphorus, or both.” <ref>“Eutrophication”. Science Daily. 1995-2009 <http://www.sciencedaily.com/articles/e/eutrophication.htm></ref> Phosphorus and nitrogen are limiting factors in natural marine and aquatic ecosystems. When quantities of these elements are released into aquatic ecosystems, algal blooms often form in response. Although eutrophication sometimes occurs naturally in marine ecosystems, many problems with eutrophication along coastlines and within smaller bodies of water like bays, lakes and rivers have been attributed human activities.
What are Algal Blooms?
Algal blooms are the “rapid excessive growth of algae, generally caused by high nutrient levels and favorable conditions.
[They can] result in deoxygenation of the water mass when the algae die, leading to the death of aquatic flora and fauna” often known as creating hypoxic zones.<ref>“Algal Bloom”. Green Facts: Facts on Health and the Environment. Sept. 10 2009. <http://www.greenfacts.org/glossary/abc/algal-bloom.htm></ref> Algal blooms can occur in both saltwater and freshwater environments although they may be more prevalent in salt water ecosystems. Because of the variety species of algae that live in these two distinct environments, algal blooms vary in color ranging from green to a yellow-brown to a red (which is more commonly known as a red tide).
How are Algal Blooms created?
Algal blooms occur in response to an increase in the quantity of a limiting nutrient in the aquatic ecosystem, most often nitrogen or phosphorus. When these chemicals come in contact with the body of water the algae and phytoplankton take advantage of the abundance of these nutrients and grow and multiply sometimes reaching concentrations of hundreds of thousands per millimeter. <ref>“Algal Bloom”. Science Daily. 1995-2009. <http://www.sciencedaily.com/articles/a/algal_bloom.htm></ref>
How do Algal Blooms affect the Ecosystems of the Chesapeake Bay?
For the Chesapeake Bay, many of the sources of nutrient pollution come from: farm fertilizer runoff (both manure and chemical fertilizer), farm pesticide runoff, and air pollution. “Air pollution from vehicles, industries, gas-powered lawn tools and other emitting sources contribute nearly one-third of the total nitrogen load to the Chesapeake's waterways.” <ref>“Nutrients”. Chesapeake Bay Program: A Watershed Partnership. Sept. 15 2009. <http://www.chesapeakebay.net/nutrients.aspx?menuitem=14690></ref>
In 2008 alone the Chesapeake Bay absorbed 13.8 million pounds of phosphorus and 291 million pounds of nitrogen. <ref>“Pollutants”. Chesapeake Bay Program: A Watershed Partnership. March 20 2009. <http://www.chesapeakebay.net/status_pollutants.aspx?menuitem=19795></ref> 38% of the total nitrogen content in the Chesapeake Bay comes from agricultural practices <ref>“Sources of Nitrogen Loads to the Bay.” Chesapeake Bay Program: A Watershed Partnership. 2007. <http://www.chesapeakebay.net/status_nitrogensources.aspx?menuitem=19797></ref> while 45% of the total phosphorus content in the Chesapeake Bay comes from agricultural origins. <ref>“Sources of Phosphorus Loads to the Bay” Chesapeake Bay Program: A Watershed Partnership. 2007. <http://www.chesapeakebay.net/status_phosphorusloads.aspx?menuitem=19801></ref> Algal blooms triggered by these pollutants create problems in the Chesapeake Bay in that they block the sunlight from reaching underwater grasses which provide food for birds and shelter for fish and crabs. Algal blooms also absorb the oxygen in the water, thus creating hypoxic zones where no species can effectively live and degrading the biodiversity of the ecosystem. <ref>“Nutrients”. Chesapeake Bay Program: A Watershed Partnership. Sept. 15 2009.<http://www.chesapeakebay.net/nutrients.aspx?menuitem=14690></ref>
Hypoxic Zones
What is Hypoxia
A phenomenon that occurs in aquatic environment as dissolved oxygen becomes reduced in concentration to a point detrimental to aquatic organisms living in the system. A system with low concentration- in the range between 1 and 30% saturation- is called hypoxic.<ref>“Hypoxia”. Wikipedia. <http://en.wikipedia.org/wiki/Hypoxia_(environmental)></ref>
Why Hypoxic Zone in Chesapeake Bay?
Human activities including fossil fuel burning and volatilization of agricultural wastes are main sources for the overenrichment of estuaries and coastal waters with nutrients, especially nitrogen.<ref>“Hypoxia Reasons”. Ecological Societ of America. <http://www.esa.org/education_diversity/pdfDocs/hypoxia.pdf></ref> Nitrogen promotes algal and zooplankton growth (as zooplankton feed on the algae), but when the organisms die and decompose they sink to the denser bottom layer of Chesapeake waters and deplete the oxygen supply other aquatic life needs to live. The lower layers doesn’t get mixed with the higher level of dissolved oxygen above and experiences very low lever or no measurable levels of dissolved oxygen.<ref>“Hypoxia Reasons”. DEQ Louisiana <http://www.deq.state.la.us/portal/LinkClick.aspx?fileticket...tabid=2958></ref>
Effects of Hypoxic Zone
Hypoxia affects the cycling of nutrient and other materials in the ecosystem, cause stress and mortality in biota, and changes interactions between predators and their prey, thus impairing normal ecosystem function.
Small zooplankton swims upward to avoid low oxygen. They may also be subject to increased predation by jellyfish, which are more tolerant of low oxygen than are other predators. Changes in zooplankton biomass and behavior may reduce key prey for larval fish that use the estuary as a nursery. Benthic organisms are especially vulnerable to hypoxia because they are unable to flee low-oxygen condition. Blue crabs are also very vulnerable to hypoxia; they may alter their migration routes to lower-bay spawning areas and many are killed due to the new route. <ref>“Hypoxia Effects”.Pewclimate <http://www.pewclimate.org/docUploads/Regional-Impacts-Chesapeake.pdf></ref>Fish-eating birds and mammals, such as herons or otters, cannot live where there are no fish. Hypoxic areas may also be more susceptible to overfishing, pest outbreaks, storm damage, or other stresses.<ref>“Hypoxia Reasons”. Ecological Societ of America. <http://www.esa.org/education_diversity/pdfDocs/hypoxia.pdf></ref>
Recent Hypoxia
The hypoxic zone of the Chesapeake Bay has more than tripled in volume within the past forty years. Data from 2006 showed that the Bay’s dead zone was the largest recorded in twenty years, reaching about 40% of the Bay’s mainstem that year.<ref>“Recent Hypoxia”. New Energy Choice <http://www.newenergychoices.org/index.php?page=ethanol_chesapeake&sd=ru></ref>
Blue Crab
Blue Crab in the Chesapeake Bay
Blue crabs have the highest value of any Chesapeake Bay commercial fishery. The Bay's commercial blue crab harvest in 2000 was valued at approximately $55 million. Not only that but they are also a keystone species, they act as pedator and prey. The blue crab is prey to animals such as striped bass, drums, eels, catfish, cownose rays and some sharks. Additionally blue crabs are carniverous, preying on their own kind. Crabs that have recently molted are at an even greater risk.<ref>“Blue Crab”. Chesapeake Bay Program. <http://www.chesapeakebay.net/bluecrab.aspx?menuitem=19367></ref> Unfortunatly Blue crab polulations have plummeted in recent years. From 791 million in 1993 down to 260 million in 2007. In 2007 there were only 44.2 million pounds of fish caught, the lowest yield since 1945. The average harvest from 1968-2005 was 73 million pounds.<ref>“Chesapeake Blue Crab”. The Blue Crab Site. <http://www.thebluecrab.com/index.html></ref>
The population of spawning-age blue crabs in the Chesapeake Bay in 2008 has dropped down to 120 million, down from 143 million in 2007.<ref>“Number of Blue Crabs in Bay Remains Below Long-Term Average”. NOAA - National Oceanic and Atmospheric Association. <http://www.noaanews.noaa.gov/stories2008/20080728_bluecrab.html></ref> The steep drop in crab population is hurting the Bay's ecosystem as well as the economic welfare of residents around the bay itself.
Reasoning behind Popluation Decline
While the bay is fished at 62% of capacity where the recommended amount is 46% the excess nutrients introduced into the bay have just as strong an effect. Nitrogen and Phosphorous build ups kill the blue crabs food. They create “dead zones” with no oxygen. These “dead zones” take away 75,000 metric tons of wildlife, enough food to support 60 million crabs. These zones are created by entry pipes; runoff from the land; and air pollution.<ref>“Nutrients”. Chesapeake Bay Program. <http://www.chesapeakebay.net/nutrients.aspx?menuitem=14690></ref>
The amount of runoff is increasing for many reasons, including increased population, and the vast increase of impervious surfaces. Impervious surfaces are hard impenetrable areas that do not allow for the absorption of excess nutrients, such as roads, rooftops, and sidewalks.<ref>“impervious surfaces”. Chesapeake Bay Program. <http://www.chesapeakebay.net/impervioussurfaces.aspx?menuitem=14670></ref> Between 1990 and 2000, impervious cover has increased by nearly 250,000 acres, and it is only expanding, critics suspect that impervious services could cover almost 1.1 million acres around the bay by 2010.<ref>“impervious surfaces”. Chesapeake Bay Program. <http://www.chesapeakebay.net/impervioussurfaces.aspx?menuitem=14670></ref>
Blue Crab Population Recently
The combined population of adult and juvenile crabs in the Bay rose to 418 million in 2008- 09 from 280 million in 2007- 08, addtionally the number of female crabs has almost doubled. This can be contributed to stricter rules for fishers, which placed many of them ont he sideline during crabbing season this past year.<ref>“Bay's blue Crab Population”. Pilot Online. <http://hamptonroads.com/2009/04/bays-blue-crab-population-increasing-state-says></ref>
However, if the agricultural runoff is not curbed, crab numbers are going to remain low becasue their habitat cannot support higher numbers. The increase in dead zones and alge is going to shrink the numbers even more, hurting the Bay, and the people around it.
Policies
Background
For the past decade, tens of thousands of farmers and thousands of conservation professionals in the government and the nonprofit community, have worked diligently to reduce agriculture’s heavy damage to the Bay.
Despite this hard work, and the billions of taxpayers’ dollars spent to study and combat the Chesapeake’s pollution problems, the Bay as a living ecosystem remains on the brink. Each of the previous three major clean up deadlines that politicians have set for themselves have been missed. The impending 2010 restoration goals is expected to be no different. <ref> Perez, Michelle et al. “Facing Facts in the Chesapeake Bay”. September 2009. Environmental Working Group. <http://www.ewg.org/conservation/chesapeake-bay-pollution/report></ref>
The main reason is agriculture. Today, farming still loads 39 percent of the nitrogen pollution, 45 percent of the phosphorus pollution into the Bay, turning it into an oxygen-starved dead zone for many species, and 60 percent of the sediment that suffocates the Chesapeake’s underwater grasses and aquatic nurseries. <ref> Perez, Michelle et al. “Facing Facts in the Chesapeake Bay”. September 2009. Environmental Working Group. <http://www.ewg.org/conservation/chesapeake-bay-pollution/report></ref>
Past Policies
In 2004, the Maryland Department of the Environment administered the Chesapeake Bay Restoration Act, which planned to upgrade the 66 largest wastewater treatment plants up to Enhanced Nutrient Reduction Standards. The ideal plan was that once these standards have been reached conservatively 7.5 million pounds of nitrogen and 260,000 pounds of phosphorus will stop going into the Bay each year.
Under the Bay Restoration Act, a septic upgrade program was enacted to reduce nitrogen. Maryland's Department of Agriculture oversees this program and has determined that fees need to be paid by on-site sewage disposal systems or septic users. These fees funded sewage system upgrades and cover crops to reduce nitrogen levels in the ground water.
In 2007, Maryland’s Storm Water Act of 2007 was signed by Governor Martin O’Mally. The regulations that took effect in early 2009 required that the environmental site design be implemented to the greatest extent that was practical, using best management practices and other design techniques.
Obama's Plan
On May 12, President Barack Obama issued an Executive Order on the Chesapeake Bay by submitting seven draft reports, prepared cooperatively by 10 federal agencies, on his plans to reduce polluted runoff from agriculture by increasing government accountability and public involvement. The Order calls for increased pollution control, habitat protection and land conservation programs at all levels of government. The purpose is to reduce urban, suburban and agricultural runoff by imposing stricter regulations and providing funding to help them comply to the new standards. <ref> “Obama Administration Releases Chesapeake Bay Restoration Plans”. September 10, 2009. Environment News Service. <http://www.ens-newswire.com/ens/sep2009/2009-09-10-01.asp></ref>
The report plans to better protect resources in the Chesapeake Bay and its tributaries under the Clean Water Act and others similar programs, strengthen storm water management practices on Federal land and develop storm water best practices guidelines, develop focused and coordinated habitat and research activities that protect and restore living resources and water quality of the Chesapeake Bay and its watershed. <ref>“Executive Summary for Draft Report Addressing Key Challenges to Chesapeake Bay Protection and Restoration”. September 9, 2009. Environmental Protection Agency et al. <http://executiveorder.chesapeakebay.net/file.axd?file=2009%2f9%2fExecutive+Summary+Draft+Reports+EO+13508.pdf></ref>
This is to be accomplished through several new initiatives. The EPA in correlation with the Chesapeake Bay states and the District of Columbia would establish a “Total Maximum Daily Load” that would include limits for nitrogen, phosphorous and sediment for point and non-point source pollution. Under the Clean Water Act, the EPA would set regulations to reduce nutrient and sediment pollution from Concentrated Animal Feeding Operations (CAFOs), storm water, and new or expanding discharges. These regulations require that they meet Bay water quality goals under set permits and strict reduction standards. The report also implements a compliant and enforcement strategy; and sets up “Healthy Bay-Thriving Agriculture Initiative” between farmers and the EPA and USDA. This report is expected to be finalized and take effect in May 2010. <ref>“Executive Summary for Draft Report Addressing Key Challenges to Chesapeake Bay Protection and Restoration”. September 9, 2009. Environmental Protection Agency et al. <http://executiveorder.chesapeakebay.net/file.axd?file=2009%2f9%2fExecutive+Summary+Draft+Reports+EO+13508.pdf></ref>
References
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