Pollution is Our Problem
Debate #1 Group C

The Chesapeake Bay was once the glittering, shimmering crown jewel of the mid-Atlantic region of the United States. Native Americans, and surely many early European settlers, learned to make their livelihoods from its wealth of resources. There was an apparently endless supply of fish and shellfish in the Bay at the time. However, as time and technology advanced hand-in-hand, the Bay’s creatures started disappearing. Overfishing led to a decline in native populations of many Bay inhabitants: among them was Crassostrea virginica, the Virginia Oyster. However, overfishing is merely a supplementary cause of the decline in the oyster population: topping the list are sedimentation and runoff from pollution.

A decreased population of native oysters is, superficially, a problem only for the few who make their living by selling them. However, this is false: oysters are extremely important filter feeders in the food web of the Chesapeake. Historically, there were enough oysters in the Bay to filter its entire volume of water every 3-4 days. Today’s oyster population, between 1/100 and 1/50 of the abovementioned historic levels, takes almost a year to filter the entire body of water. A healthy oyster population equates to a healthier Bay.

There are steps to creating a healthy oyster population. There are a significant number of people that would support the full introduction of C. ariakensis, or the Asian oyster, as a viable option. They argue that the Asian oysters are genetically superior to the Bay’s native oysters. It is true that the ariakensis variety is resistant to two diseases that have had a large impact on the virginica population (MSX and Dermo). However, it is also true that in areas protected from oyster harvesting, the native strain was able to resist and overcome pressure from both diseases. Thus, halting or reducing the harvest of oysters in the Chesapeake would result in resurgence of the population of native oysters. The fact that introduction of the Asian oyster is unnecessary is supplemented by the fact that it is extremely risky. Some scientists equate the likely results from such an introduction to the infestation of kudzu in the American southeast or the parasitic nature of Zebra Mussels in the Great Lakes.

Even if the Asian Oyster were introduced, it is likely that the pollution levels in the Bay would prohibit their propagation. Indeed it will be difficult for even the already established native oysters to survive with current pollution remaining as it is. Nitrogen that enters the Bay or one of its tributaries comes from one of many places: emissions from vehicles, factories, etc accounts for a third of all nitrogen in the Bay. Nabbing the second place trophy is runoff from fertilizers used for agricultural purposes: 26% of the Bay’s nitrogen comes from this source. From 1990-1992, 600 million pounds of nitrogen runoff entered the Bay. That unfathomable rate of pollution is a major problem for the oysters in the bay. High nitrogen levels fuel the growth of algae; this results in a drop in dissolved oxygen levels. When DO levels drop, it becomes difficult for aquatic animals (including oysters) to survive. Some of the algae are consumed by filter feeders; if there is a surplus, it dies and sinks to the bottom. Oysters are bottom dwellers, and are thus often covered in the excess algae, making it even more difficult for them to respire.

Steps must be taken to reduce the runoff from farmland into the Chesapeake Bay. Many farmers use harmful nitrogen based fertilizers because they are the most efficient and cheapest available. It would be very difficult to convince farmers to change these practices. However, there are several things that can be done. Research and development of novel, less harmful fertilizers would be extremely beneficial to the Bay’s health. Subsidizing the use of alternatives would also help. Through these methods, it is possible to reduce the amount of harmful nitrogen in the Chesapeake Bay.

Besides reducing the pollution flowing into the Bay, steps should be taken to eliminate what pollution is already in the water. One of the best ways to do this would be taking fundamental action on restoring the oyster population. For too long, the watermen have complained about the decrepit native oyster population and yet have continued to harvest them. This hypocritical behavior is a main reason for the lack of oysters in the Bay. If harder restrictions, or even a moratorium, were placed on the harvesting of oysters in Maryland and Virginia, for even a short period of time (5-10 years), the recovery of the native oyster population would be incredible.

Through a combined, comprehensive approach the native oyster population can be effectively restored. Perhaps the historical levels of abundance seem unattainable at the moment. Nevertheless, each pound of nitrogen kept out of the Bay, and each native oyster left in the Bay, is a step towards that abundance. If the waterway that so many people love and make their livelihoods from is rejuvenated, the world will know that it is possible to reverse the detriments we enact upon our surroundings.


References:

http://www.thechesapeakebay.com/article/408/chesapeake
http://www.chesapeakebay.net/nitrogen.aspx?menuitem=19412
http://www.sciencemag.org/cgi/content/full/sci;325/5944/1124?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT
http://michelledonahue.wordpress.com/2009/02/25/debate-continues-on-asian-oysters-in-the-chesapeake/

The Debate

We will argue that the real problem in the Chesapeake involves neither native nor exotic oysters, but rather too much pollution, over fishing, and habitat destruction caused by urbanization, greed and agriculture. That is, the problems and solutions for the Bay depend upon how humans live in the Bay watershed.