Ocean acidification adversely affects fish behavior

Globe and Mail : Because of humanity’s increased emissions of carbon dioxide, the world’s oceans are experiencing rising levels of acidification. To understand how that may affect fish communities, Philip Munday of the ARC Centre of Excellence for Coral Reef Studies in Australia and colleagues monitored fish living at natural carbon dioxide seeps just off the coast of Papua New Guinea. In their paper published in Nature Climate Change, the researchers say the fish living there behaved abnormally in that they were attracted to, rather than repelled by, predators and exhibited bolder behavior than similar fish in other areas. However, high CO₂ did not have any effect on their metabolic rate or athletic performance. Of particular concern is the fact that continuous exposure does not appear to reduce the effects of high CO₂ on fish behavior, which could pose a problem as ocean acidification becomes more widespread.