April 13, 2014 — 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, James Cook University and the Georgia Institute of Technology found the behavior of fish would be “seriously affected” by greater exposure to CO2.
Researchers studied the behavior of coral reef fish at naturally occurring CO2 vents in Milne Bay, in eastern Papua New Guinea.
They found that fish living near the vents, where bubbles of CO2 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 CO2-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.