EFFECTS OF MARINE RESERVES ON CORAL-REEF FISH COMMUNITIES FROM 5 ISLANDS IN NEW-CALEDONIA

The effect of marine reserve protection on coral reef fish communities was studied on five islands located in the southwest lagoon of New Ca ledonia. Commercial fish communities and Chaetodontidae, sampled befor e fishing prohibition and after five years of protection, were compare d. Reference stations were also sampled to assess variability in unpro tected communities on the same time scale. The hypothesis that marine reserves protect and develop fish stocks was confirmed. Species richne ss, density and biomass of fish on the protected reefs increased respe ctively by 67%, 160% and 246%. This increase was statistically signifi cant, whereas the reference stations showed only a small increase in d ensity. There were significant increases in the species richness, dens ity and biomass of the major exploited fish families (Serranidae, Lutj anidae, Lethrinidae, Mullidae, Labridae, Scaridae, Siganidae and Acant huridae) and also of the Chaetodontidae. No significant increase in th e mean lengths of fishes was noted among the main species, with the ex ception of one species of Siganid. Size structure changed for most of the main species, as the proportion of small individuals increased aft er five years of protection. Detrended correspondance analysis indicat ed that marine reserve protection was the most important determinant o f the fish community structure. The second determinant was the positio n along an inshore-offshore gradient. Marine reserve protection result ed in an increase in the relative abundance and species richness of la rge edible species within the assemblages.