Abstract

The progressive degradation of coral reefs is now an established fact all around the world and concerns the benthic communities as well as the fish assemblages. Marine protected areas (MPA) where human activities are restricted (fishing, diving, anchoring…) constitute a tool for their protection. In Guadeloupe (F.W.I) some coral reefs have been protected since 1979. Quantitative visual censuses of Scarid fishes, a keystone family on coral reefs, were carried out on several reefs under different status of protection. In the protected reefs areas, biomass of Scaridae was twice higher than on the reefs submitted to fishing. Their mean biomass in MPA was 5.2 kg/100 m2 whereas it was 2.8 kg 100 m2 on the non-protected reefs. Examination of the size class distribution showed that Scarid fishes of a size superior to 30 cm are only present in protected areas. The percentage of Scarid males was found to be three times higher in MPA than on the non-protected reefs (28% versus 8%). Thus, reef protection permits to ensure the reproduction of this family allowing these sequential hermaphrodite fishes to develop a more balanced sex-ratio. The exuberant development of benthic macroalgae in competition with corals is one of the major phenomena that threaten the coral reefs in the Caribbean. On the protected reefs, the increased biomass of Scaridae has authorized a better regulation of the growth of algae contrary to what was observed on non-protected reefs.

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