New research shows the disastrous consequences the world's rising carbon dioxide levels are having on ocean life.
A team of researchers from the Australian Research Council Centre of Excellence for Coral Reef Studies and James Cook University published their findings in the journal Nature Climate Change. They document how elevated CO2 is "driving fish crazy."
The Australian Associated Press reports that the new research point to ocean problems beyond acidification. From Professor Phillip Munday, one of the researchers:
''We've now established it isn't simply the acidification of the oceans that is causing disruption, as is the case with shellfish and plankton with chalky skeletons. But the CO2 itself is damaging the fishes' central nervous systems.''
Agence France-Presse reports:
The team began by studying how baby clown and damsel fishes performed alongside their predators in CO2-enriched water.
They found that while the predators were somewhat affected, the baby fish suffered much higher rates of attrition.
"Our early work showed that the sense of smell of baby fish was harmed by higher CO2 in the water, meaning they found it harder to locate a reef to settle on or detect the warning smell of a predator fish," said Munday.
The team then examined whether fishes' sense of hearing -- used to locate and home in on reefs at night, and avoid them during the day -- was affected.
"The answer is, yes it was. They were confused and no longer avoided reef sounds during the day. Being attracted to reefs during daylight would make them easy meat for predators."
Prof. Munday issued a stark warning:
“We’ve found that elevated CO2 in the oceans can directly interfere with fish neurotransmitter functions, which poses a direct and previously unknown threat to sea life,” Prof. Munday says.
Prof. Munday said that around 2.3 billion tonnes of human CO2 emissions dissolve into the world’s oceans every year, causing changes in the chemical environment of the water in which fish and other species live.