Abstract

Marine Protected Areas (MPA) have been implemented in several places with the hope of reversing population decreases commonly observed in many marine resources. In this study, a comparison of the total density and adult density, population structure and frequency of reproductive evidence of the commercially important gastropod Eustrombus gigas, was made between a fished area in Mexico and an MPA in Cuba. At each area three climatic periods were included (rainy, dry and cold front periods) during 2009 to 2010 on 9 transects into the MPA and 15 transects into fished area. The total densities were 4 times higher on the MPA than fished area. Moreover, the adult densities were 20 times higher on the MPA than fished area. Apparently, the conch population at MPA is constituted by small conchs, with a gradual increase in weight and lip thickness, turning them into "dwarf" conchs. This fact was possibly density-dependent; on the other hand, the fished area showed that adult conchs are very scarce. In addition, is possible the presence of Allee effect in the area. Reproductive evidence was observed during the whole year in MPA, which suggests the existence of an important queen conch reserve in the southeastern region of Cuba and an apparently self-sufficient population for recruitment; in contrast, reproductive activity was very scarce in fished zone. Two effects were observed on this study, both important as fishery management of the conch population; consequently, both must be considered at the new revision of the management plans on each area.

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