How does rising atmospheric CO2 affect marine organisms?

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Primary Production in the Southern Ocean: 1997-2006
Smith Jr., W.O. and Comiso, J.C. 2008. Influence of sea ice on primary production in the Southern Ocean: A satellite perspective. Journal of Geophysical Research 113: 10.1029/2007JC004251.

What was done
In their study of the primary productivity of the Southern Ocean, the authors employed phytoplankton pigment assessments, surface temperature estimates, modeled irradiance, and observed sea ice concentrations -- all of which parameters were derived from satellite data -- and incorporated them into a vertically-integrated production model to estimate productivity according to the technique of Behrenfeld et al. (2002). Of this effort, they say that "the resultant assessment of Southern Ocean productivity is the most exhaustive ever compiled and provides an improvement in the quantitative role of carbon fixation in Antarctic waters."

What was learned
"During the nine years (1997-2006) analyzed in this study," in the words of Smith and Comiso, "ice concentrations decreased slightly (~2% per decade)." In addition, they report that "productivity in the entire Southern Ocean showed a substantial and significant increase during the nine-year observation period," which we calculate from the graphical representation of their results to be ~17% per decade.

What it means
In commenting on their results, the two researchers note that "the highly significant increase in the productivity of the entire Southern Ocean over the past decade implies that long-term changes in Antarctic food webs and biogeochemical cycles are presently occurring," as the greening of the earth -- even at sea! -- continues.

Behrenfeld, M, Maranon, E., Siegel, D.A. and Hooker, S.B. 2002. Photo-acclimation and nutrient-based model of light-saturated photosynthesis for quantifying ocean primary production. Marine Ecology Progress Series 228: 103-117.

Reviewed 20 August 2008