How does rising atmospheric CO2 affect marine organisms?

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The Power of Marine Life to Cope with Environmental Change
Volume 17, Number 14: 2 April 2014

In their introduction to a special issue of the Philosophical Transactions of the Royal Society B, devoted to the subject of ocean acidification and climate change, Godbold and Calosi (2014) say there are "important knowledge gaps that require urgent attention," one of which is suggested by their rhetorical question: "Can organisms' capacity for phenotypic buffering and adaptation offset the consequences of environmental change?"

Focusing on this question, the two UK researchers write that "organisms continuously adjust their physiological status as the physico-chemical environment around them fluctuates and changes," which phenomenon is known as phenotypic plasticity and is dealt with in depth by Somero and Hochachka (2002) and Ghalambor et al. (2007). And these adjustments, as they continue, are made "in order to maintain optimal levels of energy production, fundamental to sustain cell repair, growth and reproductive investments (Sibly and Calow, 1986)." However, they write that "in general, evolutionary aspects of ocean acidification, alone, and in combination with other stressors, have largely been overlooked." And, consequently, they indicate that "projections of the likely consequences of environmental change, ignore species' capacity for phenotypic buffering and the propensity for adaptation."

As for the ramifications of these facts, Godbold and Calosi say "it has become clear that future empirical studies will need to incorporate longer incubation periods that allow to incorporate seasonal environmental processes, and, where possible, multiple generations, to enable organisms to fully express their phenotypic plasticity," without which they suggest that incorrect conclusions could well be drawn.

Further support for this perspective is provided by one of the contributions (Russell et al., 2014) to the special issue of the Philosophical Transactions. In that study, the researchers concluded that "the structure of future ecosystems may not be predictable using short-term laboratory experiments alone, owing to potentially confounding effects of exposure time and effects of being held in an artificial environment." Instead, they state that "a combination of laboratory (physiology responses) and large, long-term experiments (ecosystem responses) may therefore be necessary to adequately predict the complex and interactive effects of climate change as organisms may acclimate to conditions over the longer term."

Clearly, there are sometimes no "quick and dirty ways" of resolving complicated real-world questions involving complex life processes; and that is likely why nature's secrets are typically hidden from the eyes of the impatient.

Sherwood, Keith and Craig Idso

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.

Godbold, J.A. and Calosi, P. 2014. Ocean acidification and climate change: advances in ecology and evolution. Philosophical Transactions of the Royal Society B 368: 10.1098/rstb.2012.0448.

Russell, B.D., Connell, S.D., Findlay, H.S., Tait, K., Widdicombe, S. and Mieszkowska, N. 2014. Ocean acidification and rising temperatures may increase biofilm primary productivity but decrease grazer consumption. Philosophical Transactions of the Royal Society B 368: 10.1098/rstb.2012.0438.

Sibly, R.M. and Calow, P. 1986. Physiological Ecology of Animals: An Evolutionary Approach. Blackwell Scientific Publications, Hong Kong.

Somero, G.N. and Hochachka, P.W. 2002. Biochemical Adaptation: Mechanism and Process in Physiological Evolution. Oxford University Press, Oxford, United Kingdom.