Creation of complex reef structures through coral restoration does not affect associated fish populations on a remote, well-protected, Caribbean reef

Abstract

Coral reef ecosystems are facing severe degradation due to anthropogenic activities at both local and global scales. In response, extensive restoration efforts are underway, aiming to bolster coral cover and enhance reef fish communities to foster facilitation between fish and corals. This reciprocal relationship is anticipated to improve overall restoration efficacy and enhance coral reef resilience in the face of global warming. Here, we investigate the impact of coral restoration using out-planted Acropora cervicornis colonies attached to raised domes on the associated fish community on the isolated, well-protected reef of Little Cayman Island in the Central Caribbean. Surveys were conducted immediately preceding out-planting, five days later, and 85 days later to capture temporal changes in the fish community. After 85 days of out-planting, there were no changes in fish biomass, abundance, or species richness for the entire fish community. This pattern was consistent for selected fish functional groups. Additionally, no significant differences were observed in the fish community before outplanting, five days after out-planting, or 85 days after out-planting of restoration domes. Our results underscore the limited impact of coral restoration for influencing fish communities in the isolated and highly protected reef of Little Cayman over an 85-day period. Consequently, our findings have implications for using coral restoration as a mechanism to enhance fish populations, particularly in marginally disturbed regions where structural complexity has not been lost. Future restoration programs should therefore incorporate local knowledge of environmental history and restoration needs along with an increased data-driven understanding of the intricate interaction between fish and coral populations to be successful.