Factors Affecting the Survival of Fingerling Red Drum in Freshwater Ponds

Abstract

Abstract Survival of fingerling red drum (Sciaenops ocellatus) in freshwater ponds has been erratic. Rate of salinity lowering, chloride level, salt or chloride source, and predator control were evaluated as factors affecting survival of fingerling red drums stocked in freshwater ponds. Two 30-d trials were conducted in 0.04-hectare ponds stocked at a density of 2,500 fish/hectare. Twelve ponds were used in trial 1 to assess effects of two chloride levels (150 and 300 mg/L) and two salinity-lowering regimes (2 and 6 h). Survival was poor in all treatment combinations (1.2% overall). No fish survived at a chloride level of 150 mg/L, and only 2.3% survived at 300 mg/L. Salinity-lowering regime did not affect survival. Eighteen ponds were used in trial 2 to evaluate two higher chloride levels (250 and 400 mg/L), two salt or chloride sources (sodium chloride and calcium chloride), and predator control treatments (pond insecticide treatment and net enclosures). Survival was significantly higher when chloride l...