A MARICULTURE DEMONSTRATION PROJECT FOR AN ALTERNATIVE HARD CLAM FISHERY IN SOUTH CAROLINA: PRELIMINARY RESULTS1

Intensive hard clam (Mercenaria mercenaria) culture for the production of large seed and/or market size quahogs is being investigated as an alternative or supplemental clam fishery for South Carolina. A combination of cage culture and aggregate cover (crushed gravel) is being used in subtidal, intertidal, and floating configurations. Young seed clams (ȳ size = 3.4 mm) are planted at four densities (500, 1,000, 2,500, 5,000 m-2) in both production and experimental culture units at each of four locations along the South Carolina coast. Experimental units are divided into 0.1 m2 compartments to provide monthly replicate samples for each density. Coincidental water samples are taken monthly at each location for determinations of chlorophyll a, nitrate and nitrite nitrogen, orthophosphate, silicate, total organic carbon, particulate organic carbon, and dissolved organic carbon, as well as standard hydrographic parameters (temperature, salinity, turbidity). Results from preliminary bottom tray culture studies as well as ongoing cageaggregate culture are presented and discussed.