Ocean acidification, which is driven by rising atmospheric carbon dioxide levels, may cause sharks to
be less interested in hunting prey, according to research published in Global Change Biology. In laboratory experiments emulating CO2 concentrations as they are expected to be by the middle and end of this century, scientists from the U.S. and Australia found that the smooth dogfish shark became uninterested in squid odors — sometimes avoiding them altogether. Sharks in control waters pursued prey scents four times more often than sharks in waters with high CO2 levels, the study found. Rising ocean acidity can disrupt the proper firing of neurons, the scientists say, because it interferes with a specific receptor present in most marine organisms with a nervous system. A study earlier this year found that fish in waters with increased acidity were also less able to detect predator odors.