The growth and survival of brown shrimp (Penaeus aztecus) and blue crabs (Callinectes sapidus) in ponds receiving heated bay water from an electric power plant.

The present study was designed to measure the survival, growth, food conversion, and condition of blue crabs (Callinectes sapidus Rathbun) and brown shrimp (Penaeus aztecus Ives) reared in 0.1 ha ponds receiving a continuous flow of heated water from an electric power plant. Two ponds were stocked with 100 blue crabs each. In the 6 month experiment, survival was 3-27%, growth was 15.8-18.5 mm per month, yields were 7.8-80.5 kg per ha (6.9- 71.0 pounds per acre), and food conversion rates were 32.1-328.0 g of feed per gram increase of crab. Eleven 0.1-ha ponds were stocked with 5,000 postlarval brown shrimp each. Five ponds were stocked in April and six in July, 1972. My results are similar to those obtained in non-flowing ponds in that (1) shrimp growth is markedly slowed as mean length approaches 100 mm and (2) failure to control predation and competition can markedly reduce yield. Nevertheless, these results show improved brown shrimp yields as compared to those reported for non-flowing ponds. Where predation and competition were controlled and supplemental food was provided, survival was 58-97%, growth was 1.2-1.4 mm per day, yields were 318-596 kg ha (280-526 lbs per acre), and food conversion rates were 1.5-3.9 g of feed per gram increase of shrimp for periods of 10-12 weeks.