How does rising atmospheric CO2 affect marine organisms?

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Reef Fish Robustness in the Vicinity of Underwater CO2 Seeps

Paper Reviewed
Munday, P.L., Cheal, A.J., Dixson, D.L., Rummer, J.L. and Fabricius, K.E. 2014. Behavioral impairment in reef fishes caused by ocean acidification at CO2 seeps. Nature Climate Change 4: 487-492.

According to Munday et al. (2014), "there is growing concern that rising CO2 levels and ocean acidification will have profound impacts on marine biodiversity and the function of marine ecosystems," citing Wittmann and Portner (2013). However, they note that "most evidence for negative effects of ocean acidification comes from short-term laboratory experiments on single species," and that "there is increasing evidence that some species can adjust to high CO2 levels over the longer term," citing Form and Riebesell (2012), Miller et al. (2012), Parker et al. (2012) and Dupont et al. (2013). In further exploring the subject, Munday et al. took advantage of naturally acidified seawater in the vicinity of Papua New Guinea, which is located near cool volcanic seeps that raise the acidity of the nearby seawater to levels similar to projections for the coming century, in order to test for the effects of continuous exposure to elevated CO2 on reef fish behavior and metabolism in their natural habitat, and to examine the potential consequences for reef fish communities.

The five scientists determined that high CO2 did not have any effect on metabolic rate or aerobic performance. And they say that contrary to expectations, "fish diversity and community structure differed little between CO2 seeps and nearby control reefs." In light of these welcome findings, Munday et al. conclude that "recruitment of juvenile fish from outside the seeps, along with fewer predators within the seeps, is currently sufficient to offset any negative effects of high CO2 within the seeps."

Dupont, S., Dorey, N., Stumpp, M., Melzner, F. and Thorndyke, M. 2013. Long-term and trans-life-cycle effects of exposure to ocean acidification in the green sea urchin Strongylocentrotus droebachiensis. Marine Biology 160: 1835-1843.

Form, A.U. and Riebesell, U. 2012. Acclimation to ocean acidification during long-term CO2 exposure in the cold-water coral Lophelia pertusa. Global Change Biology 18: 843-853.

Miller, G.M., Watson, S.A., Donelson, J.M., McCormick, M.I. and Munday, P.L. 2012. Parental environment mediates impacts of increased carbon dioxide on a coral reef fish. Nature Climate Change 2: 858-861.

Parker, L.M. Ross, P.M., O'Connor, W.A., Borysko, L., Raftos, D.A. and Portner, H.-O. 2012. Adult exposure influences offspring response to ocean acidification in oysters. Global Change Biology 18: 82-92.

Wittmann, A.C. and Portner, H.-O. 2013. Sensitivities of extant animal taxa to ocean acidification. Nature Climate Change 3: 995-1001.

Posted 1 October 2014