Rising carbon dioxide in oceans makes fish lose fear of predators, scientists say
Escalating carbon dioxide emissions will cause fish to lose their fear of predators, potentially damaging the entire marine food chain, joint Australian and US research has found.
Escalating carbon dioxide emissions will cause fish to lose their fear of predators, potentially damaging the entire marine food chain, joint Australian and US research has found.
A study by the Australian Institute of Marine Science (Aims), James Cook University and the Georgia Institute of Technology found the behaviour of fish would be "seriously affected" by greater exposure to CO 2.
Researchers studied the behaviour of coral-reef fish at naturally occurring CO 2 vents in Milne Bay, in eastern Papua New Guinea.
They found that fish living near the vents, where bubbles of CO 2 seeped into the water, "were attracted to predator odour, did not distinguish between odours of different habitats, and exhibited bolder behaviour than fish from control reefs".
The gung-ho nature of CO 2-affected fish means that more of them are picked off by predators than is normally the case, raising potentially worrying possibilities in a scenario of rising carbon emissions.
More than 90 per cent of the excess CO 2 in the atmosphere is soaked up by the oceans. When CO 2 is dissolved in water, it causes ocean acidification, which changes its chemistry.