Monday, May 18, 2009

Ocean Acidification a negative feedback.

(PhysOrg.com) -- Groundbreaking Victoria University research shows that ocean acidification may have no negative effect on tropical corals and local sea anemones - in fact it may improve photosynthesis.

Ocean acidification is when carbon dioxide from the atmosphere dissolves into our oceans and makes them more acidic. Research to date has shown that if carbon dioxide emissions are not reduced, ocean acidification could have severe—and irreversible—consequences for marine life.

But Victoria Master’s student Michael Doherty says his research shows that ocean acidification has no negative effect on photosynthesis in the coral and sea anemone he studied, and that it might actually improve the process.

“Plants and algae get carbon from the atmosphere in the form of carbon dioxide, and photosynthesis is the process by which the organism turns this carbon into sugar—providing essential energy for life. Algae live within ‘animals’ like corals and anemones, and through photosynthesis provide energy for themselves and the animal,” says Mr Doherty.


Indeed Ingrid Zondervan found similar findings with Phytoplankton,

GLOBAL BIOGEOCHEMICAL CYCLES, VOL. 15, No. 2, PAGES 507-516, JUNE 2001

Decreasing marine biogenic calcification: A negative feedback on rising atmospheric pCo2

Ingrid Zondervan, Richard E. Zeebe1, Björn Rost, and Ulf Riebesell
Alfred Wegener Institute for Polar and Marine Research Bremerhaven, Germany

Abstract. In laboratory experiments with the coccolithophore species Emiliania huxleyi and Gephyrocapsa oceanica, the ratio of particulate inorganic carbon (PIC) to particulate organic carbon (POC) production decreased with increasing CO2 concentration ([CO2]). This was due to both reduced PIC and enhanced POC production at elevated [CO2]. Carbon dioxide concentrations covered a range from a preindustrial level to a value predicted for 2100 according to a "business as usual" anthropogenic CO2 emission scenario. The laboratory results were used to employ a model in which the immediate effect of a decrease in global marine calcification relative to POC production on the potential capacity for oceanic CO2 uptake was simulated. Assuming that overall marine biogenic calcification shows a similar response as obtained for E. huxleyi or G. oceanica in the present study, the model reveals a negative feedback on increasing atmospheric CO2 concentrations owing to a decrease in the PIC/POC ratio

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