Scientists at the University of Adelaide say that their research has revealed that future ocean acidification will severely decrease the ability of baby fish to locate a home and grow into adulthood. The researchers report that normal ocean sound cues that aid baby fish in home location will become completely distorted due to the levels of CO2 that will increased until the end of the century.
"Locating appropriate homes is a crucial step in the life cycle of fish," Tullio Rossi, co-author of the study, said in a press release. "After hatching in the open ocean, baby fish travel to reefs or mangroves as safe havens to feed and grow into adults. Baby fish can find those places through ocean noise: snapping shrimps and other creatures produce sounds that the baby fish follow."
However, when the inevitable increase in oceanic acidity occurs, Rossi and his colleagues claim that the neurological pathways in the fish will become damaged and cause them to swim away from these sounds instead of towards them.
The experiments examined barramundi hatchlings and found that high CO2 levels makes their movement slower and increases hiding behavior.
"Such misinterpretation of sound cues and changes in other behaviours could severely impact fish populations, with the number of young fish finding safe habitats dramatically reduced through their increased vulnerability to predators and reduced ability to find food," said Ivan van Nagelkerken, lead researcher of the study.
The findings are published in the Dec. 15 issue of the Proceedings of the Royal Society B.