Assessment of Prerelease Diet Regimes on Growth of Juvenile Atlantic Sturgeon

Abstract

AbstractTo determine whether the growth rates of juvenile Atlantic sturgeon Acipenser oxyrinchus would be improved if the fish were weaned to natural food before being released into a simulated natural environment, 60 sturgeon from the 2006 and 2007 year‐classes (ages 2 and 1, respectively) were subjected to two prerelease diet regimes (n = 30 per treatment, 120 total). Each year‐class was divided into two groups, a control group that was fed a commercial diet for 10 d until stocking into a 0.2‐ha earthen pond in June 2008 and a treatment group that was weaned to natural food over a 10‐d period before stocking. Final sampling (84 d poststocking) showed that year‐class had an effect on the specific growth rate (% weight gain/d) but that treatment did not. The survival rates were 77% and 80% among the controls from the 2007 and 2006 year‐classes and 87% and 90% among the treatment fish. This study shows that weaning to natural food before release into a natural environment does not significantly affect the specific growth or survival rates of Atlantic sturgeon.