Atlantic States Marine Fisheries Commission and

Abstract.—We investigated the effect of rearing density on the growth and survival of juvenile Atlantic sturgeon Acipenser oxyrinchus using initial rearing densities ranging from 10 to 30 fish per tank or 3.6–10.9 kg/m2 of substrate. The mean weight of fish at the start of the trial was 368.7 g. After 7 weeks of rearing, density ranged from 6.5 to 16.3 kg/m2 (14.7–36.6 g/L). Fish reared at the lowest density had significantly higher mean weight and length at the end of the trial. Growth over the 7-week experiment was modeled as a function of time, and growth rate was inversely proportional to density. The mean increase in total biomass was 63.14%, and the mean daily length gain was 0.23%. Overall survival was 99.7%, and calculated feed conversion rates ranged from 1.93 to 2.65. However, feed conversion rates were likely not at maximum levels due to the selection of a relatively high experimental feeding rate (2.5 % of body weight per day). As a result of excessive commercial harvests, Atlantic sturgeon Acipenser oxyrinchus popula-tions experienced dramatic declines in abundance across much of their range throughout the late 1800s. By the 1920s, intense harvests had severely reduced the vulnerable spawning populations (Taub 1990). Recent evidence suggests that be-tween 1977 and 1995 the number of juvenile At-lantic sturgeon in the Hudson River, which sup-ports one of the largest remaining populations in the northeastern United States, declined by ap-proximately 80 % (Peterson et al. 2000). In fact, it is now believed that recruitment in the Hudson River is insufficient to sustain the population (Pe-terson et al. 2000). The continued decline of Atlantic sturgeon across their historic range has prompted both th