Assessment of Coral Reef Status and Associated Fish Diversity Along Ondo State Coastline

Coral reef ecosystems are among the most biologically productive marine habitats and support significant coastal fisheries and biodiversity. Along the Ondo State coastline within Nigeria's South West geopolitical zone, reef-like hard substrate structures and associated fish communities have been reported but remain scientifically undocumented. This study presents the first systematic assessment of hard substrate benthic communities and associated fish diversity along a 30 km section of the Ondo coastline near Igbokoda. Underwater visual census surveys were conducted by snorkeling and SCUBA diving at eight stations during the dry season, when water clarity was highest. Benthic cover was estimated using point intercept transects, and fish species were recorded using belt transects. Results identify sparse hard coral patches dominated by Acropora and Porites species, with significant coverage of macroalgae indicating elevated nutrient loading from coastal runoff. Fish diversity is moderate, with 46 species recorded, including several commercially important grouper and snapper species. No dedicated marine protection exists for these reef structures, and artisanal dynamite fishing was observed at two survey stations. The study recommends the urgent establishment of a no-take zone around the most intact reef patches, engagement with artisanal fishing communities in alternative livelihood and reef restoration programs, and submission of site data to the Nigerian Institute for Oceanography and Marine Research. Keywords: coral reef, fish diversity, Ondo State coastline, South West Nigeria, marine conservation