Human impacts on ecosystems can disrupt the fundamental ecological relationships that create patterns of diversity in free-living species. Despite the abundance, ubiquity, and ecological importance of parasites, it is unknown whether the same decoupling effects occur for parasitic species. We investigated the influence of fishing on the relationship between host diversity and parasite diversity for parasites of coral reef fishes on three fished and three unfished islands in the central equatorial Pacific.
Results/Conclusions
Fishing was associated with a shallowing of the positive host-diversity–parasite-diversity relationship. This occurred primarily through negative impacts of fishing on the presence of complex life-cycle parasites, which created a biologically impoverished parasite fauna dominated by directly transmitted parasites resilient to changes in host biodiversity. Parasite diversity appears to be decoupled from host diversity by fishing impacts in this coral reef ecosystem, which suggests that such decoupling might occur in other ecosystems affected by environmental change.