Altered Behaviors of Reef Fish in Bleached Coral Environments and their Imposed Impacts on Reef Fish Populations

Aaron Clausen \ Oceans First, Issue 4, 2017, pgs. 9-15.  Download PDF


For the first time in history atmospheric carbon levels have reached and exceeded 400ppt. This exponential increase in atmospheric carbon has lead to the major changes in the climate that has significantly impacted coral reef health across the wold. Global temperature rise is increasing ocean temperatures, and acidity. These stressors have lead to large scale bleaching of corals. The degradation of these corals has been linked to multiple noteworthy changes in the behaviours of reef fish inhabiting bleached corals. Reef fish are not responding to predator cues as they would in pristine reefs, as the cues related to the presence of a predator are not being detected by reef fish. Despite the loss of camouflage resulting from bleached white coral backgrounds reef fish have been displaying more aggressive behaviour, resulting in increased vulnerability to predators. The settlement preferences of reef fish have been altered, resulting in migration from their bleached environments to healthier reefs. These changes are lowering prey fish populations and influencing change in reef population dynamics. This review will synthesize key findings involving altered behavior of reef fish, and the impacts of these changes on reef populations.