Virginia, the top producer of Crassostrea virginica (Eastern Oyster) on the United States East Coast, supports a substantial commercial shellfish aquaculture industry valued at over $30 million. Biofouling, the aquatic communities that adhere to submerged structures, can have ecologic, biologic, and economic impacts on aquaculture operations. Colonized bags have increased weights that affect handling and blockages that can impede essential water flow, which could affect conditions within grow-out bags and have dramatic effects on oyster production costs and final market price. This study aimed to (1) identify and quantify fouling communities and (2) determine the effects of biofouling control practices and stocking density on biofouling communities measured by assessing, (a) biofouling weight on oyster bags and (b) biofouling on mesh settlement plates attached on the outside and suspended within floating oyster bags subjected to the different treatment combinations. Colonizing organisms (tubeworm fouling and bryozoans) were the most prominent taxa found across most settlement mesh plates. Air drying frequently reduced biofouling, producing significantly lighter wet weights on mesh plates and grow-out bags than non-air-dried treatments (p < 0.01). While not significant, higher stocking density tended to reduce biofouling in non-air-dried treatments. Understanding which biofouling communities grow on oyster bags and developing mechanisms to control fouling growth can help researchers provide better data for oyster farmers so they can make more informed husbandry decisions.

Primary Presenter: Zophia Galvan Lam, Frostburg State University (z.galvan@outlook.com)

Authors:

Zophia Galvan, Frostburg State University  (z.galvan@outlook.com)

Julia Grenn, Virginia Institute of Marine Science  (jmgrenn@vims.edu)

William Walton, Virginia Institute of Marine Science  (walton@vims.edu)