Field comparison of survival and growth of hatchery-reared versus wild blue crabs, Callinectes sapidus Rathbun

Abstract

The efficacy of restocking as a fisheries management tool depends upon the ability of hatchery-reared juveniles to survive, grow and reproduce in the wild following release. However, hatchery-reared animals may be maladapted to the natural environment as a result of morphological, physiological, or behavioral deficiencies acquired during the hatchery phase. To assess the competency of hatchery-reared blue crabs Callinectes sapidus Rathbun, a species under consideration for restocking in Chesapeake Bay, we compared survival and growth of hatchery-reared and wild juveniles using complementary field tethering experiments and small-scale field releases in shallow blue crab nursery habitats of the upper Chesapeake Bay. We observed no difference in the survival rates of hatchery-reared and wild crabs in either tethering experiments or paired field releases. Hatchery-reared and wild juveniles also exhibited similar growth rates and levels of growth variability. The results indicate that hatchery-reared juveniles are competent and likely not disadvantaged relative to wild conspecifics, and that poor performance of hatchery-reared individuals following release is not a significant barrier to restocking for this species in Chesapeake Bay. Further, our study highlights the potential utility of release experiments with hatchery-reared animals to provide key biological data for stock assessments and fishery management.