Abstract

The queen conch (Strombus gigas) is an intensively exploited species all over the Caribbeans and particularly in the Guadeloupian archipelago. Considering the local economical importance of this species and the threats on the regional stock, the Regional Fisheries Committee is initiating a study aiming to achieve a first assessment of the Guadeloupian stock variation. A simple methodology allowing the evaluation of the densities of the queen conch using an underwater towed camera was developed in order to be freed from logistical and financial diving constraints. This first step allowed us to operate the settlings of this method through a first estimation of stocks densities in eight sites, from the Grand Cul-de-Sac Marin to Marie Galante. This protocol offers the advantage of sampling large surfaces in reasonable time and for a moderate cost. The experimental average density was estimated about 37.52 conches/ha, with a minimum of 12.9 conches/ha and a maximum of 65.1 conches/ha, for a total sampled surface of 47,700 m². The study reveals that large areas are needed to evaluate the state of this resource whose distribution is very dynamic and heterogeneous. This reliable and easily implemented method is strictly necessary to estimate the exploitable stock of Queen conches on a large scale and at every depth it could be found. This process will be applied to the evaluation of the stocks of Queen conches in the archipelago, and more broadly applied to the monitoring of other exploited resources. It was first applied for the determination of the initial state of a bay of Marie Galante, which will be the site of a future fishing reserve project.

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