Abstract
Within the last five decades, northern hard clam, Mercenaria mercenaria, aquaculture has grown into a thriving industry along the east coast and, notably, the Gulf Coast of Florida. Within the Gulf of Mexico, the Cedar Key area is flourishing as a producer of hard clams with about 125 million clams harvested annually. This industry brings $45 million a year into the area's economy and supports over 500 jobs. The purpose of this study is to determine if M. mercenaria can be grown in Mississippi waters and contribute to a new aquaculture product for the state. Clams were ordered from a Florida commercial seed supplier and deployed in July 2020 at three separate sites: Cat Island, Deer Island, and Point Aux Chenes Bay. These sites predominately vary by salinity regime, which is a primary driver of clam survival and growth. The mean salinity for Cat Island is 20.7 ppt, Deer Island is 14.1 ppt, and Point Aux Chenes Bay is 19 ppt; Cat Island being closest to the optimal salinity range. To test the importance of predation at these sites, the clams were placed inside mesh bags underneath crab traps to examine predation at each site where half of the traps were enclosed with mesh to exclude all potential predators and the rest were not enclosed, allowing access to all large predators. Each treatment type (i.e., mesh covered crab trap and non-covered crab trap) was replicated 3 times at each site. Clam mortality and growth will be measured semimonthly until the clams are market size (anticipated to be approximately 12 months). Completion of this work will determine if northern hard clam aquaculture is possible in coastal Mississippi.
