From Nature.com, is there anything trace amounts of CO2 can’t do? As if clownfish (the test subject) don’t already act funny.
The New Scientist says:
Carbon dioxide in the ocean acts like alcohol on fish, leaving them less able to judge risks and prone to losing their senses. The intoxication adds to the threats that global warming and ocean acidification pose to marine ecosystems.
Here’s the paper in Nature Climate Change:
Göran E. Nilsson, Danielle L. Dixson, Paolo Domenici, Mark I. McCormick, Christina Sørensen, Sue-Ann Watson & Philip L. Munday
Nature Climate Change (2012) doi:10.1038/nclimate1352
Received 18 August 2011, Accepted 29 November 2011, Published online 15 January 2012
Predicted future CO2 levels have been found to alter sensory responses and behaviour of marine fishes. Changes include increased boldness and activity, loss of behavioural lateralization, altered auditory preferences and impaired olfactory function1, 2, 3, 4, 5. Impaired olfactory function makes larval fish attracted to odours they normally avoid, including ones from predators and unfavourable habitats1, 3. These behavioural alterations have significant effects on mortality that may have far-reaching implications for population replenishment, community structure and ecosystem function2, 6. However, the underlying mechanism linking high CO2 to these diverse responses has been unknown. Here we show that abnormal olfactory preferences and loss of behavioural lateralization exhibited by two species of larval coral reef fish exposed to high CO2 can be rapidly and effectively reversed by treatment with an antagonist of the GABA-A receptor. GABA-A is a major neurotransmitter receptor in the vertebrate brain. Thus, our results indicate that high CO2 interferes with neurotransmitter function, a hitherto unrecognized threat to marine populations and ecosystems. Given the ubiquity and conserved function of GABA-A receptors, we predict that rising CO2 levels could cause sensory and behavioural impairment in a wide range of marine species, especially those that tightly control their acid–base balance through regulatory changes in HCO3− and Cl− levels.
The Daily Bayonet sums up this research pretty well:
That researchers chose the colorful and movie-famous clownfish as the subject for their study instead of the toadfish or other, less photogenic, aquatic reef dwellers, has nothing to do with winning headlines and funding. Probably.