It is a little over a decade since research commenced into the effects of anthropogenic ocean acidification on marine fishes. In that time, we have learned that projected end-of-century CO2 levels can affect the physiology, growth and survival of some species, but not others. There are also wide-ranging effects on behaviour that could alter the performance and survivorship of some species. However, these effects are context and species specific, and the results depend on how experiments are done. In a provocative article published in Nature, Clark et al. claimed that ocean acidification does not impair the behaviour of coral reef fishes and that previous studies are not repeatable. In this talk I outline the overwhelming evidence from a decade of research showing that elevated CO2 can affect the behaviour of a wide variety of fishes, including coral reef fishes, and I describe how methodological differences explain why different studies yield different results. I conclude by considering the possible effects of ocean acidification on reef fishes compared with other, more immediate, threats from climate change.
Professor Philip Munday is a Chief Investigator and Reef Research Leader in the ARC Centre of Excellence for Coral Reef Studies at James Cook University in Townsville. He has broad interests in the ecology and evolution of reef fishes. His primary research focuses on predicting the impacts that climate change and ocean acidification will have on populations and communities of marine fishes, both directly through changes in the physical environment and indirectly through effects on coral reef habitat. Using a range of laboratory and field-based experiments the research group he leads is investigating the effects of climate change on fish populations and testing their capacity for acclimation and adaptation to a rapidly changing environment.