Phase I striped bass hauled in varying levels of sodium chloride (NaCl) had significantly higher survival than fish hauled in varying levels of calcium chloride (CaCl2), regardless if the fish came from a hard water or soft water hatchery. The addition of MS-222 to the transport water did not have a beneficial effect on phase I striped bass survival.
Striped bass fingerlings (Morone saxatilis) acclimated to hard water (110 mg/liter as calcium carbonate, 41.0 mg/liter as calcium) were exposed for 96 hours at pH 7.7, 6.1, or 4.2 in hard water. In another experiment, striped bass fingerlings acclimated to soft water (32 mg/liter as calcium carbonate, 9.5 mg/liter as calcium) were exposed for 96 h at pH 7.7, 6.1, or 4.2 in soft water. No mortalities occurred during the experiments. The primary stress response and electrolyte disturbance were less severe in fish acclimated to hard water than in fish acclimated to soft water, suggesting that...
Survival and the stress response of striped bass Morone saxatilis during transport and for a 1-month recovery period after transport were evaluated in 2 studies. In the first study, fish from Carbon Hill National Fish Hatchery (CHNFH), a hard water hatchery (total hardness, 100 mg/liter as calcium carbonate), were transported and recovered for 1 month at the Southeastern Fish Cultural Laboratory (SFCL), a hard water facility (total hardness, 108 mg/liter as calicum carbonate). In the second study, fish from Warm Springs National Fish Hatchery (WSNFH), a soft water hatchery (total hardness...
Ammonia is the primary nitrogen-containing waste product of fish. Under natural conditions, ammonia is converted first to nitrite and then to nitrate. Ammonia and nitrite are toxic to fish at low levels, but nitrate is relatively non-toxic. Ammonia has a variety of toxic effects, including reduced growth rates, whereas nitrite primarily interfers with oxygen transport. The literature pertaining to toxic levels and effects of environmental ammonia and nitrite as well as experimental methods of inhibiting these toxicities are reviewed. Prevention of elevated pH for high ammonia conditions,...
Channel catfish can be cultured at high densities in carefully managed recirculating raceway systems. Various flow rates, exchange rates, and tank to filter ratios were investigated in ten recirculating systems employing biological filters, settling chambers and foam strippers. Limestone, shells, styrofoam and teflon rings served as effective filter media, but coal slag restricted water flow and was not satisfactory. An equation was developed to evaluate the effects of system design on water quality. Water quality varies directly with fresh water exchange, flow rate per tank, and the...
An indoor recirculating system was designed to evaluate the effects of a high flow rate and a high filter to tank ratio on the carrying capacity of a closed system for channel catfish culture. Updraft and trickling filters with various filter media were evaluated. A net gain of 319 pounds, with a standing crop of 405 pounds at a density of 7.2 pounds per cubic foot, was obtained over a 142 day growing period.
The Journal of the Southeastern Association of Fish and Wildlife Agencies presents papers that cover all aspects of the management and conservation of inland, estuarine, and marine fisheries and wildlife. It aims to provide a forum where fisheries and wildlife managers can find innovative solutions to the problems facing our natural resources in the 21st century.