Abstract

The source of recruits to populations of three reef fish species found in Bermuda, Haemulon flavolineatum, Abudefduf saxatilis and Thalassoma bifasciatum were examined through the technique of allozyme electrophoresis. Levels of genetic variation observed were within the range recorded for other marine teleosts. Allelic frequencies were compared between populations sampled from Bermuda, Miami, Bahamas and Barbados; no evidence of significant heterogeneity was observed between these populations of Abudefduf saxatilis and Thalassoma bifasciatum; however indications of population substructuring were observed in Haemulon flavolineatum, suggesting that gene flow was restricted and that genetic divergence in the Bermuda population had occurred. Reports in the literature indicate that this species has a relatively short larval residence period of two weeks, and it is proposed that this may not be sufficiently long to allow ‘foreign’ recruits to migrate to Bermuda. It may be inferred from this that the population of H. flavolineatum in Bermuda is largely self-replenishing, and if the limiting factor is the pelagic larval duration (PLD), then other species with similarly short PLD’s might be expected to show evidence of stock heterogeneity. This study confirms the need for stringent local fisheries management policies, and adds further support for the implementation of a local fish pot ban in 1990.

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