How does rising atmospheric CO2 affect marine organisms?

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A Real-Life Non-Calcifying Anthozoan-Symbiodinium Symbiosis
Jarrold, M.D., Calosi, P., Verberk, W.C.E.P., Rastrick, S.P.S., Atfield, A. and Spicer, J.I. 2013. Physiological plasticity preserves the metabolic relationship of the intertidal non-calcifying anthozoan-Symbiodinium symbiosis under ocean acidification. Journal of Experimental Marine Biology and Ecology 449: 200-206.

The authors write that "some species inhabiting highly heterogeneous environments, such as intertidal habitats, have evolved the ability to exhibit high levels of physiological plasticity (e.g. Stillman and Somero, 1996, 2000)," which is "the mechanism whereby organisms alter their physiology enabling them to persist in new environmental conditions (i.e. phenotypic plasticity; Ghalambor et al., 2007), including decreased pH (Calosi et al., 2013, Miller et al., 2012)."

What was done
Continuing the quest for additional knowledge in this realm of research, Jarrold et al. say they "investigated the physiological plastic responses and performance of an intertidal non-calcifying anthozoan-Symbiodinium symbioses exposed to simulated future ocean acidification conditions," working with the intertidal sea anemone, Anemonia viridis, which hosts Symbiodinium from clade a (Bythell et al., 1997)."

What was learned
The six scientists determined that even following a reduction in seawater pH to 7.4, "the photosynthetic capacity of the symbiosis was preserved." And they say that "this along with the unaffected anemone respiration rates indicated that the metabolic relationship was also preserved."

What it means
In expressing the ultimate implications of their findings, Jarrold et al. state that "physiological plasticity could be an important mechanism enabling sea anemones to be successful in a future high CO2 world."

Bythell, J.C., Douglas, A.E., Sharp, V.A., Searle, J.B. and Brown, B.E. 1997. Algal genotype and photo-acclimatory responses of the symbiotic alga Symbiodinium in natural populations of the sea anemone Anemonia viridis. Proceedings of the Royal Society of London B 264: 1277-1282.

Calosi, P., Rastrick, S.P.S., Lombardi, C., de Guzman, H.J., Davidson, L., Jahnke, M., Giangrande, A., Hardege, J.D., Schulze, A., Spicer, J.I. and Ganbi, M.-C. 2013. Adaptation and acclimatization to ocean acidification in marine ectotherms: an in situ transplant experiment with polychaetes at a shallow CO2 vent system. Philosophical Transactions of the Royal Society B 368: 10.1098/rstb.2012.0444.

Ghalambor, C.K., McKay, J.K., Carroll, S.P. and Reznick, D.N. 2007. Adaptive versus non-adaptive phenotypic plasticity and the potential for contemporary adaptation in new environments. Functional Ecology 21: 394-407.

Miller, G.M., Watson, S.-A., Donelson, J.M., McCormick, M.I. and Munday, P.L. 2012. Parental environment mediates impacts of elevated CO2 on a coral reef fish. Nature Climate Change 2: 858-861.

Stillman, J.H. and Somero, G.N. 1996. Adaptation to temperature stress and aerial exposure in congeneric species of intertidal porcelain crabs (genus Petrolisthes): correlation of physiology, biochemistry and morphology with vertical distribution. Journal of Experimental Biology 199: 1845-1855.

Stillman, J.H. and Somero, G.N. 2000. A comparative analysis of the upper thermal tolerance limits of eastern Pacific porcelain crabs, genus Petrolisthes: Influences of latitude, vertical zonation, acclimation and phylogeny. Physiological and Biochemical Zoology 73: 200-208.

Reviewed 30 July 2014