How does rising atmospheric CO2 affect marine organisms?

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Effects of Elevated CO2 on Pineapple
Zhu, J., Bartholomew, D.P. and Goldstein, G. 1997. Effect of elevated carbon dioxide on the growth and physiological responses of pineapple, a species with crassulacean acid metabolism. Journal of the American Society of Horticultural Science 122: 233-237.

What was done
The authors grew the CAM plant Ananas comosus L. (pineapple) in open-top chambers maintained at atmospheric CO2 concentrations of 330 and 730 ppm for four months to study the effects of elevated CO2 on the growth of this important agricultural species.

What was learned
The 400-ppm increase in the air's CO2 concentration boosted average rates of net assimilation in pineapple plants by 36%. Carbon isotopic discrimination measurements additionally indicated that CO2 uptake via the CAM pathway was enhanced more by the elevated CO2 than was CO2 uptake via the C3 photosynthetic pathway. Hence, enhanced rates of nocturnal CO2 fixation in CO2-enriched plants were primarily responsible for the observed 23% increase in plant dry mass at harvest.

What it means
As the air's CO2 concentration continues to increase, it is likely that pineapple plants will display enhanced rates of photosynthesis and biomass production and, hence, greater marketable yield. Thus, pineapple production in tropical areas should increase in the future, even if air temperatures rise, for pineapple plants typically exhibit no physiological injuries at air temperatures as high as 50C.

Reviewed 27 November 2002