Rising carbon dioxide levels in the ocean may be confusing coral reef fish and sending them swimming toward the smell of predators and, therefore, toward death, the Los Angeles Times reported.
The findings are from a study led by Philip Munday, a marine ecologist at James Cook University in Queensland, Australia, and published Tuesday in the Proceedings of the National Academy of Sciences.
"What we wanted to find out was how it (ocean acidification) affects those (forms of marine life) that don't have a skeleton on their outside," Munday told the Times.
In the experiment carried out with baby clownfishes - the same type of fish that starred in Finding Nemo - and with damselfishes, scientists found fish exposed to the most carbon dioxide seemed attracted to odors that should have set off biological alarms, the paper reported.
The scientists also made temporary one-fish habitats in the sand for the fish exposed to the carbon dioxide. They found that fish exposed to the highest levels were more bold and aggressive as they struck at potential food and that they were five to nine times more likely to die, the paper reported.
Mark Hay, a marine ecologist at the Georgia Institute of Technology not involved in the study, told the Times, "Here's an example of a dramatic alteration in the (biological) machinery... that would be catastrophic for young fish."