Tolerance of Shortnose Sturgeon, Acipenser brevirostrum, Juveniles to Different Salinity and Dissolved Oxygen Concentrations1

Abstract

Cultured shortnose sturgeon juveniles, age 11-330 days, were exposed to different salinity (0-35 ppt) and dissolved oxygen concentrations (2.0-5.0 mg/liter) in a series of experiments designed to examine tolerance levels. Tolerance to in- creased salinity improved with age. Fish 76 days old experienced 100% mortality in a 96-hour test when exposed to salinities >15 ppt while 330-day-old fish tolerated salinities as high as 20 ppt for a duration of 18 hours but exhibited 100% mortality at 30 ppt. Younger fish were also more susceptible to low oxygen concentrations than older fish. In a 6-hour test, fish 64 days old exhibited 86% mortality when exposed to DO concentrations of 2.5 mg/liter. However, sturgeon >100 days old were able to tol- erate concentrations of 2.5 mg/liter with <20% mortality. Proc. Annu. Conf. Southeast. Assoc. Fish and Wildl. Agencies 47:476-484