Researchers in French Polynesia found that predators substantially reduce both the number and variety of young coral reef fish by eating them indiscriminately soon after they settle on reefs, rather than targeting specific species. The team built 21 artificial patch reefs in Moorea's lagoon and randomly assigned them to three treatments: caged reefs that excluded predators, uncaged reefs exposed to predators, and partial cage controls. They monitored fish recruitment over 54 days during the 2008 summer spawning season. Predators reduced recruit abundance by 74% compared to reefs where predators were absent. Species richness was 42% lower on reefs exposed to predators. Predators foraged non-selectively among species, affecting all families rather than targeting specific ones. The reduction in species diversity was caused by fewer total fish rather than selective predation on rare species. The research shows that predation can fundamentally alter coral reef fish community structure by indiscriminately reducing fish numbers soon after settlement. Understanding these community-level effects helps explain how predators shape the diversity patterns we see on coral reefs and could inform reef management strategies.
Citation
Heinlein, J. M.; Stier, A. C.; Steele, M. A. (2010). Predators reduce abundance and species richness of coral reef fish recruits via non-selective predation. Coral Reefs.
Cite this article
Heinlein et al. (2010). Reef Predators Reduce Young Fish Across Species. Ocean Recoveries Lab. https://doi.org/10.1007/s00338-010-0592-7
