Value of Off-bottom Oyster Aquaculture Baskets as Habitat for Juvenile Blue Crab

Abstract

The potential of the adjustable long-line system (ALS) oyster aquaculture baskets as habitat for juvenile blue crab was investigated in Portersville Bay, AL, during Summer/Fall 2014. The density of juvenile blue crabs associated with baskets containing single shells oysters was not significantly greater than the density of juvenile blue crabs on/in baskets without single shell oysters. This suggested crabs were primarily attracted by the physical structure of the baskets, rather than the additional structure provided by the presence of oysters within the ALS baskets. The baskets as habitat appeared to be degraded by the presence of large blue crabs among the baskets. The potential of visible implant elastomer (VIE) tags as a tool to assess habitat quality in terms of juvenile crab site fidelity, survivorship, and growth was also assessed. The effect of VIE tags on survival was negligible. Crabs had an 85% tag retention rate after 16 weeks, validating VIE as a suitable tag for mark-recapture.