Impact of hurricane Dean on coral reef benthic and fish structure of Martinique, French West Indies

The impact of hurricane Dean was assessed on the Caribbean southern reef of Martinique (French West Indies). A line-intercept transect method was used to assess benthic communities and an underwater visual census technique was employed on a 50 m long transect to evaluate fish assemblages. Univariate and multivariate statistical tools were used for data analysis. Correlated changes of benthic and fish communities were found along the 15 months post-hurricane. The effects of hurricane Dean can be divided into (I) immediate and rapid effects and (2) gradual effects. The former has been linked to the rapid destruction and reorganization of the reef habitat. A significant decline of the mean coral cover (from 37% to 23%) associated with a rapid colonization by macroalgae communities was recorded. The significant benthic community modifications changed fish species richness, abundance and community structure. The second effect relates to the ability of reef species to adapt to new environmental conditions. Populations of two damselfish species (Pomacentridae) have taken advantage of reef destruction to expand their territory and favoured the spread of the macroalgae community. As a result, the fish community was significantly modified while the habitat complexity was considerably reduced due to digitate coral destruction.