The influence of pearl oyster farming on reef fish abundance and diversity in Ahe, French Polynesia

•This research investigated the effects of pearl oyster farming on reef fish in a Polynesian lagoon.•Pearl farming on Ahe does not appear to negatively alter fish abundance and community structure.•Reef fish could be used to monitor the relative impacts of pearl farming on biodiversity.

Many cultured pearl farms are located in areas of the Pacific that have thriving, highly diverse fish communities but the impacts of farming on these communities are poorly understood. We studied the effects of pearl oyster farming on shore fish abundance and diversity in the lagoon of Ahe, French Polynesia by adapting roving diver census methods to the coral reef bommies of the lagoon and compared 16 sites with high pearl farming impact to others with no direct impact. Pearl farming has a slightly positive effect on reef fish abundance (N) and no significant impact on fish diversity (H) or community composition. This is important when considering the ecological sustainability of pearl farming in French Polynesia and suggests that a potential synergy between pearl farms and marine conservation should be further explored.