Bleaching coral event due to cold waters in the Gulf of California: effect on Pocillopora cryptofauna

Coral reef fauna is imperiled by the loss of coral cover due to increased mass bleaching. However, few studies have focused on the immediate effects of bleaching on the closely coral-associated fauna. Here, we investigated the impact of a coral bleaching event due to abnormally cold waters in the Gulf of California on Pocillopora-associated fauna. We focused on the cryptobenthic reef fishes (CRFs) and crustacean coral symbionts that are likely the most sensitive to habitat degradation because of their poor mobility. We found that a moderate bleaching event (similar to 50% of Pocillopora cover) did not affect the occurrence of crustaceans. In contrast, bleaching was significantly associated with a decrease in CRFs numbers, particularly for the non-gobiids, revealing a shift in assemblage composition. Our study highlights that the CRFs, essential for reef functioning, are very sensitive to early signs of habitat alteration.

Automated summary

This study investigated the impact of a coral bleaching event on the closely coral-associated fauna in the Gulf of California. The results showed that a moderate bleaching event did not affect crustaceans, but significantly decreased the numbers of cryptobenthic reef fishes, especially the non-gobiids.