Large-scale distribution of queen conch nursery habitats: implications for stock enhancement

Seagrass beds of moderate shoot density serve as the primary nursery habitat for queen conch(Strombus gigas) in the central Bahamas. Despite large expanses of seagrasses on Exuma Bank,large, long-term aggregations of juvenile conch are limited to a few particular sites. The positionsof historically important nurseries are related to tidal excursion of oceanic water onto the Bank, butnot with patterns of larval dispersion. Nursery locations appear to be related to production (and notstanding crop) of certain macroalgal species that provide food for juvenile conch.High mortality and low growth rates of conch transplanted to sites without resident juveniles suggestthat conch nurseries are ecologically unique habitats, and that stock enhancement is likely tobe most successful in habitats known for queen conch. Trophodynamic processes, both above andbelow the conch, probably determine the distribution of the species; knowledge of these mechanismswill be key to successful stock enhancement.