Abstract

Queen conch, Strombus gigas, is an important fisheries species that has been over-harvested in many locations throughout the Caribbean including Florida. The conch population in the Florida Keys has been slow to recover due, in part, to diminished recruitment and declining environmental conditions. Therefore, it is crucial to evaluate the efficacy of management strategies aimed at conserving and restoring queen conch populations. As such, this study examined the effects of juvenile conch habitat quality on metamorphosis. Competent conch larvae were exposed to sediment and water collected from two nearshore sites adjacent to the land and two offshore sites along the reef tract in the Florida Keys. Juvenile conch aggregations were present at all sites. Metamorphic response to nearshore and offshore treatments were similar (p < 0.05), and the average number of larvae that metamorphosed ranged from 62% to 85%. In addition, there was no significant difference in metamorphic response for larvae exposed to site sediment with site water or to those larvae exposed to site water only (p < 0.05). However, larvae that metamorphosed when exposed to nearshore treatments were not as robust (defined as crawling on the substrate and searching for food with proboscis) as those exposed to offshore treatments. These findings indicate that both nearshore and offshore habitats are favorable settlement locations for competent larvae; however, nearshore sites may not have the same quality as offshore sites. Resource managers can apply these results to assist in defining critical juvenile nursery grounds for conservation and stock enhancement.

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