Scientists have confirmed that coral bleaching adversely affects reef fish communities in a study published in a recent issue of the journal PLoS ONE.
The study by Nicholas Graham and coauthors examined the effects of the mass coral-bleaching event resulting from the El Nio episode of 1997"98, focusing on the fish communities in 66 study sites throughout the Indian Ocean (in the Maldives, Chagos, Seychelles, Kenya, Tanzania, Mauritius, and Runion).
The authors used computer models to demonstrate that that changes in the size structure, diversity and trophic composition of the reef fish community have followed coral declines.
The authors detected "...declines in fish species richness across the western Indian Ocean in response to loss of live coral cover. Although only a small proportion of species are heavily coral dependent, most species are reliant on the reef matrix at some stage in their life history, and change in species richness was likely due to loss in the physical structure of the reef, rather than live coral."
Corallivores and planktivores were found to be the most vulnerable groups of fishes to the loss of coral cover and "...are likely to be the groups most threatened from the predicted ongoing decline in global reef health."
For more information, see the paper: Graham NAJ et al. (2008) Climate warming, marine protected areas and the ocean-scale integrity of coral reef ecosystems. PLoS ONE 3, e3039. doi: 10.1371/journal.pone.0003039.