How does rising atmospheric CO2 affect marine organisms?

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Coccolithophores Can Evolve to Cope With Ocean Acidification
Paper Reviewed
Lohbeck, K.T., Riebesell, U. and Reusch, T.B.H. 2014. Gene expression changes in the coccolithophore Emiliania huxleyi after 500 generations of selection to ocean acidification. Proceedings of the Royal Society B 281: 10.1098/rspb.2014.0003.

Lohbeck et al. (2014) write that "evolutionary adaptations in key phytoplankton species have only recently come into the focus of marine ecology and biogeochemistry." But they say "such processes are of high relevance for a comprehensive understanding of how global change will affect marine ecosystem functioning and biogeochemical cycles," referencing, in this regard, the studies of Lohbeck et al. (2012), Reusch and Boyd (2013) and Sunday et al. (2014).

Hoping to add knowledge to this topic, in a laboratory study, Lohbeck et al. determined the expression levels of ten candidate genes putatively relevant to pH regulation, carbon transport, calcification and photosynthesis in E. huxleyi populations that were short-term exposed to ocean acidification conditions subsequent to acclimation (a physiological response) and after 500 generations of high CO2 adaptation (an adaptive response).

According to the three researchers, "in the adaptive response, putative pH regulation and carbon transport genes were up-regulated, matching partial restoration of growth and calcification in high CO2-adapted populations." Quoting Lohbeck et al., it would appear that "adaptive evolution may thus have the potential to partially restore cellular pH regulatory capacity and thereby mitigate adverse effects of ocean acidification." And who knows what additional benefits another 500 generations of adaptive evolution might provide???

Lohbeck, K.T., Riebesell, U. and Reusch, T.B.H. 2012. Adaptive evolution of a key phytoplankton species to ocean acidification. Nature Geoscience 5: 346-351.

Reusch, T.B.H. and Boyd, P.W. 2013. Experimental evolution meets marine phytoplankton. Evolution 67: 1849-1859.

Sunday, J.M., Calosi, P., Dupont, S., Munday, P.L., Stillman, J.H. and Reusch, T.B.H. 2014. Evolution in an acidifying ocean. Trends in Ecology and Evolution 29: 117-125.

Reviewed 17 September 2014