How does rising atmospheric CO2 affect marine organisms?

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Global Climate Change and Red Seaweed Production in China
Zou, D. and Gao, K. 2014. Temperature response of photosynthetic light- and carbon-use characteristics in the red seaweed Gracilariopsis lemaneiformis (Gracilariales, Rhodophyta). Journal of Phycology 50: 366-375.

Gracilariopsis lemaneiformis or red seaweed is used throughout Asia for various purposes and is one of the most important aquaculture species in China, which in that country is cultivated for its high-quality raw agar. At its culture site on Nanao Island, Shantou, China, however, the seaweed experiences high variability in environmental conditions, which creates concerns about how it will fare in light of the additional global climate changes that are predicted to occur in response to earth's increasing atmospheric CO2 concentration.

What was done
In a laboratory study, in the words of the two Chinese researchers, "G. lemaneiformis was cultured at 12, 19, or 26°C for three weeks, to examine its photosynthetic acclimation to changing temperature."

What was learned
Zou and Gao determined that "the irradiance-saturated rate of photosynthesis ... increased with increasing temperature," such that "both the photosynthetic light- and carbon-use efficiencies increased with increasing growth or temperatures (from 12°C to 26°C)."

What it means
In the concluding paragraph of their paper, the two scientists say their results suggest that "G. lemaneiformis can optimize metabolic balance by adjustment of the light- and carbon-use in harmony with the changes in the prevailing temperature conditions," which leads them to propose that "ongoing climate change (increasing atmospheric CO2 and global warming) might exert a favorable influence on the mariculture of G. lemaneiformis through the improved photosynthetic performances."

Reviewed 2 July 2014