Marine Protected Areas (MPA) are often contemplated as a tool for the
sustainable management of exploited resources and ecosystem conservation.
This paper proposes an approach to establish a statistical diagnostic of the
effects of MPAs on fish assemblages, and define corresponding ecological
indicators. This requires choosing relevant variables (abundance, diversity,
demographic parameters ...) and appropriate statistical methods. The
study was based on data from the Abore reef Reserve in New Caledonia. Two
sets of methods: 1-inferential linear models (ANOVA, GLM); 2- Partial Least
Squares (PLS) methods of regression, were used to test the effects of this
MPA. PLS enabled us to test simultaneously within a model, density, species
richness, biomass and mean size variables of fish community to retain the
most sensitive and relevant ones. Habitat variability was also taken into
account in these models. Species were grouped according to several criteria:
1- feeding habit; 2- taxonomy; 3- mobility; 4- adult size; 5- demographic
strategy. No significant effect of the opening of the Abore reef to fishing
was found for mobility. Feeding habit was the only criterion for which the
results from the inferential models and PLS showed a significant effect of
reserve status for all variables. Species richness, density, and to a lesser
extent mean size, were sensitive to the removal of reserve status, but not
biomass. Results from ANOVA and PLS regression were consistent but the
latter allows a more holistic approach as it integrates all variables
within a single model.