Extensive Culture of Penaeid Shrimp in Louisiana Salt-marsh Impoundments

Abstract

Wild and hatchery-produced shrimp were stocked in two impoundments off Bayou Jean Lacroix in 1968 and 1969. Maximum annual harvest was 141.2 kg/hectare of wild shrimp averaging 119 mm in total length (73 count per kg, heads on) from an impoundment in which attempts were made to remove predators and competitors. Harvest in an impoundment in which predators and competitors were not removed was 48.2, 79.1, and 161.9 kg/hectare of wild shrimp, blue crabs, and large fishes, respectively. Lack of predator control resulted in about a four-fold decrease in survival of marked white shrimp (Penaeus setiferus). Daily growth rates of juvenile and subadult brown shrimp (P. aztecus) ranged from 1.3 to 1.9 mm and 0.27 to 0.5 mm, respectively, during the investigation. Brown shrimp remaining in an impoundment for the entire 200-day annual growing season attained 164 mm. Subadult white and pink (P. duorarum) shrimp grew at rates of 0.48 and 0.18 mm/day, respectively. A marking-recapture study indicated that 70% of subadult brown shrimp were captured during 5 nights of harvesting at an impoundment weir in June, while only 53% of subadult white shrimp were recovered during 22 nights in November. Peak egress of subadult and adult brown shrimp during spring and summer occurred during full and new moons. An apparently causal relationship between decreasing water temperature and white shrimp egress was observed. White shrimp did not survive impoundment life during the winter of 1968-69.