How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic

Little Auks of the Arctic: Can They Handle a Big Climate Change?
Gremillet, D., Welcker, J., Karnovsky, N.J., Walkusz, W., Hall, M.E., Fort, J., Brown, Z.W., Speakman, J.R. and Harding, A.M.A. 2012. Little auks buffer the impact of current Arctic climate change. Marine Ecology Progress Series 454: 197-206.

The authors state that little auks (Alle alle) are the most numerous seabirds in the North Atlantic, with an estimated population of 40 to 80 million individuals, citing Stempniewicz (2001); and they say they consume up to 24% of local plankton production, citing Karnovsky and Hunt (2002). Also of note, they indicate that "little auk field metabolic rate is 70% higher than predicted by body mass, and they have very limited capacity to store fat." Consequently, they say that little auks "are predicted to be particularly sensitive to altered feeding conditions," citing Harding et al. (2009). More specifically, they write that the recent work of Karnovsky et al. (2010) "showed a very strong link between summer SST [sea surface temperature] within the foraging areas of little auks, species composition of local zooplankton communities, and dietary preferences of the birds, whereby colder water contained more larger coeppods, which were also preferentially fed upon by little auks," so that "birds had to feed on smaller, less profitable copepod species in warmer water." And as a result of these observations, they hypothesized that "higher SSTs would modify little auk diet, foraging effort, provisioning rates, breeding success and adult survival," which they presumed would significantly decline in response to warming.

What was done
In an integrative study of the behavior, physiology and fitness of colonies of little auks at three sites of significantly different temperature - Kap Hoegh, East Greenland (70°43'N, 22°38'W), Hornsund, West Spitsbergen (77°00'N, 15°22'E), and Kongsfjorden, West Spitsbergen (79°01'N, 12°25' E) - Gremillet et al. evaluated the effects of ocean warming on little auks across the Greenland Sea over the period 2005-2007, presuming that "comparing the ecophysiology of little auks from different colonies subject to contrasting SST regimes at one moment in time" would allow them to "simulate the effect that increasing water temperatures might have on this Arctic species across the 21st century."

What was learned
"During the study period," in the words of Gremillet et al., "little auks maintained their fitness despite contrasting ocean surface temperatures and copepod availability across the Greenland Sea." Indeed, they write that "contrary to our hypothesis, the birds responded to a wide range of sea surface temperatures via plasticity of their foraging behavior, allowing them to maintain their fitness levels," which indicates that "they are successful at dealing with the influence of current climate change in the Arctic."

What it means
In what constitutes the concluding sentence of their paper's abstract, the team of nine scientists from eight countries (Canada, Denmark, France, Ireland, Norway, Poland, South Africa and the United States) writes that "predicted effects of climate change are significantly attenuated by such plasticity, confounding attempts to forecast future effects of climate change using envelope models," which latter technique was initially used by numerous climate alarmists in an attempt to convince the world that earth's plant and animal species could not alter their normal behavior patterns in ways required to survive climate-model-predicted global warming. Clearly, life on earth is much more resilient than anti-CO2 doomsayers make it out to be.

Harding, A.M.A., Egevang, C., Walkusz, W., Merkel, F., Blanc, S. and Gremillet, D. 2009. Estimating prey capture rates of a planktivorous seabird, the little auk (Alle alle), using diet, diving behavior, and energy consumption. Polar Biology 32: 785-796.

Karnovsky, N., Harding, A.M.A., Walkusz, V., Kwasniewski, S., Goszczko, I., Wiktor, J., Routti, H., Bailey, A., McFadden, L., Brown, Z., Beaugrand, G. and Gremillet, D. 2010. Foraging distributions of little auks (Alle alle) across the Greenland Sea: Implications of present and future climate change. Marine Ecology Progress Series 415: 283-293.

Karnovsky, N.J. and Hunt Jr., G.L. 2002. Estimation of carbon flux to dovekies (Alle alle) in the North Water. Deep Sea Research II 49: 5117-5130.

Stempniewicz, L. 2002. Alle alle little auk. The Journal of the Birds of the Western Palearctic. Oxford University Press, Oxford, United Kingdom. BWP Update 3: 175-201.

Reviewed 31 October 2012