Acidic Oceans May Cause Clownfish to Swim Straight to Their Doom

Sure, the planet's increasing carbon dioxide levels are making the oceans more acidic, but what does that really mean for sea life? We've already heard that the ocean's changing chemistry is damaging corals and interfering with mussels, but that's just the beginning. It turns out things could get seriously weird. In a paper published this week in The Proceedings of the National Academy of Sciences, researchers led by Philip L. Munday of James Cook University have given us a concrete example: the increased CO2-levels make some fish purposely swim towards predators. As part of his experiment, Munday used a Y-shaped maze to force baby clownfish to choose between two paths. One path reeked of rock cod, a natural predator; the other had no danger scents. Munday's team compared the choices of fish raised in water of varying carbon dioxide concentrations, from today's levels of 390 parts per million up to ...