EXPERIMENTAL POND GROW-OUT OF RED DRUM, SCIAENOPS-OCELLATUS, IN SOUTH-CAROLINA

This study assessed the production potential of red drum, Sciaenops oc ellatus, in intensive pond culture. Six 0.1-ha saltwater ponds at the Waddell Mariculture Center were stocked in April 1986 with juvenile re d drum (1.7-4.3 g) produced from captive South Carolina brood stock. S tocking densities of 7500, 15 000 and 22 500 fingerlings/ha were compa red in duplicate ponds. The fish were fed a 38% protein commercial tro ut diet (Zeigler Bros.). Salinity averaged 28 +/- 3 ppt, and mean wate r exchange rates were 16.4%, 17.5% and 27.4% per day for the 7500, 15 000 and 22 500 fish/ha densities, respectively, during the 18-month st udy. A 0.75-hp fountain-type aerator was utilized in the two high dens ity ponds during warm weather in year 1 (1986), and 1-hp paddlewheel a erators were used on a near continuous basis in all ponds during year 2 (1987). An infestation of the parasitic dinoflagellate, Amyloodinium , caused complete mortality of fish reared in one of the highest densi ty ponds on day 146, and a dissolved oxygen depletion resulted in an e stimated 35% loss in one medium density pond on day 432. At harvest (2 8 September-5 October 1987), mean fish weights were 1.3, 1.0, and 1.2 kg, respectively, at the three densities. Harvested biomass averaged 8 997.5 kg/ha at the 7500 fish/ha density, with a mean survival of 88.7% . Survival, mean fish weight and crop size at harvest for the medium d ensity (15 000 fish/ha) pond affected by low dissolved oxygen levels w ere 54.7%, 0.9 kg, and 7251.3 kg/ha, respectively. In contrast, fish i n the other medium density pond exhibited 94.9% survival, 1.1 kg mean fish weight and 15 011.3 kg/ha at harvest. The single remaining high d ensity (22 500 fish/ha) pond produced 24 082.5 kg/ha of 1.2 kg fish wi th 90.6% survival. Food conversion averaged 2.43 (range 2.15-2.60). Th e fish were sold whole at pond bank to commercial dealers for $1.65-2. 75/kg.