Abstract

The queen conch (Strombus gigas) supports the second-most valuable demersal fishery in the Caribbean region. As fishing pressure has increased, local conch populations have declined, resulting in the imposition of strict harvest regulations. In Florida, the recreational queen conch fishery was c10sed in 1986 in response to concerns about the depleted stock. Our observations in the laboratory and field suggest that anthropogenic activities may adversely affect queen conch viability. In the laboratory, growth rates and den sities of conch larvae were enhanced by ozonation of seawater, which increases the oxidationreduction potential (ORP) of sea water. Low ORP is indicative of increased eutrophication. Additionally, field studies suggest that eutrophication may negatively affect conch reproductive potential. In Florida, adult conch spawn only in offshore regions and are isolated from adult conch in nearshore areas by a deep-water channel that has unsuitable benthic habitat. Anecdotal reports indicate, however, that conch recently spawned in nearshore locations. Histological examinations showed deficits in the condition of gonads from nearshore females and males relative to the gonads in their offshore counterparts. This evidence, coupled with the well-documented nutrient gradients from nearshore to offshore, suggest that conch spawning populations may be adversely affected by eutrophication.\As the south Florida and Caribbean human populations expand, so too will the burden on the marine resources resulting in the inevitable conflict between users of those resources and promoters of coastal development. If Caribbean conch fisheries are to remain viable and if the Florida fishery is to reopen, it is critical that an accurate assessment of the potential effects of these activities on queen conch populations is conducted.

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