The Effects of Artificial Substrates Containing Magnesium on Juvenile Oyster Recruitment and Fitness

Presentation: PowerPoint 

Author(s): Matt S. Elder and Dr. Patrice Ludwig James Madison University

Abstract: Oysters worldwide have seen sharp population declines, including the Chesapeake Bay’s Eastern Oyster, Crassostrea virginica. This decline stems from disease, pollution, and overharvesting. Restoration methods such as the use of artificial substrates are being used to help stimulate population growth. However, other novel methods need to be examined such as altering the local mineral content in artificial substrates. The addition of magnesium has been shown to improve the health of other bivalves, and increased incorporation could lead to oysters that grow faster and are more resistant to ocean acidification. My research will test effects of oysters attaching to substrates with increased magnesium levels. In the Chesapeake Bay, 24 oyster bags will be deployed, each containing natural shell, concrete shells, or concrete shells with magnesium carbonate. In addition, treatment shells with attached oysters will be subjected to steadily lowered pH in a lab setting to determine if increased magnesium incorporation leads to a resistance to ocean acidification. Ideally, juvenile oysters will be shown to prefer, and show increased fitness when attached to substrates with magnesium.