Oyster Populations

The decline of native Eastern Oyster, Crassostrea virginica, in the Chesapeake Bay has had both economic and ecological consequences on its surrounding community. Ecologically oysters are not only ecosystem engineers, but also keystone species within their community, meaning without them other organisms are drastically affected. Economically, oysters are a valuable commodity which has led to a considerable deterioration of oyster populations. Over harvesting and destruction of habitat can be attributed to great reductions of the oyster population. A sharp decrease in oyster populations leads to a loss in the ecosystem services they provide which in turns negatively affects the Chesapeake Bay. Due to this reduction various strategies have been implemented to revive the oyster population.

For decades the delicacies of oysters have been enjoyed throughout the world so much that a lot of the worlds’ oysters come from America, and more specifically the Chesapeake Bay. Oysters are truly a hot commodity in the Northeastern US, as they are collected for food and lime, as well as provide many fisherman and their families a way of life. Sadly, extensive overharvesting, destruction of oyster reefs, and diseases have all contributed to the loss of oyster populations. Where there was once 20 million bushels of oysters in the late 1800’s, by the end of the 20th century there were fewer than 20,000 bushels (Brumbaugh et al.). According to Airoldi, Laura, et al., estimate that 85% of oyster reefs have been lost globally. The expansion of cities led to a direct habitat loss for oysters as the reefs were demolished to provide access to commercial ships (Airoldi, Laura, et al.). Equally, power dredging, a technique still used today to dig up oysters...

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...ity rates of animals due to lack of oxygen within the water. As reported by, Cerco, C. F., & Noel, M.R., express that an increase in the oyster population could significantly improve water quality of the estuary. Experimental results indicate clearance of solids from the water column by oysters can enhance the activity of benthic microalgae, thereby altering sediment-water nutrient exchange and sediment diagenetic processes (Newell et al. 2002; Porter et al. 2004). Restoration of oysters can increase nitrogen removal from 20% to 50% through denitrification and sediment retention. Computed surface chlorophyll is reduced by 30% for a tenfold increase in oyster density and is halved when oysters are restored to historic density (Cerco, C. F., & Noel, M. R.). All in all oyster restoration can be viewed as a way to remedy cultural eutrophication in the Chesapeake Bay.