Oyster growers harvest oysters from Chesapeake Bay. Credit: NOAA.

Last week, NCCOS aquaculture researcher Dr. Suzanne Bricker gave the Kiwanis Club of Mt. Airy, Maryland, an overview of how oyster aquaculture in Chesapeake Bay is helping both growers and the environment.

Excess nutrients in Chesapeake Bay, from land-based runoff, are the biggest challenge to achieving good ecosystem health in the bay. High levels of nitrogen and phosphorus can cause large algal blooms, which can produce toxins and rapidly deplete the water of oxygen when they decompose.

Nutrient sources are multiple and diverse and there is no single solution to manage them all, but shellfish — mussels, clams, and oysters — have been shown to remove these nutrients by filter feeding phytoplankton from the water (see video below). The harvest of one million, three-inch oysters can remove 198 pounds of nitrogen and 22 pounds of phosphorus from the bay.
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The total number of oysters harvested from the bay accounts for only a small fraction of the nutrient inputs, but oyster harvesting does offer state officials another tool in their efforts to achieve good water quality in the bay. Two Maryland oyster growers have even received economic compensation from the state for the nutrient removal provided by their oysters.

In addition to seafood production and nutrient removal, oyster aquaculture cages have been shown to increase fish populations, providing another valuable ecosystem service.

Dr. Bricker’s engaging presentation resulted in an invitation to speak to the Kiwanis Club of Leesburg, Virginia, at a later date. Kiwanis International is a community service club founded in 1915 in Detroit, Michigan, with chapters across the country and in more than 80 nations around the world.