Heatwave impacts on reef fishes

While it is clear that corals are highly vulnerable to thermal stress, less attention has been paid to other components of the reef community. Having monitored Kiritimati’s coral reef fish communities using underwater visual census since 2007, we were able to assess how the 2015-2016 El Niño impacted these species.

In our April 2020 publication in Ecological Applications, led by former MSc student Jenn Magel, we showed that reef fishes are highly sensitive to increased water temperatures, declining by 50% during the El Niño-induced heatwave. Reef fishes likely moved to deeper waters to avoid the stressful conditions, and while most species returned to normal numbers within a year of the event, obligate corallivore numbers remain depressed.

For more on this study see our article in The Conversation and our Media page.