Study: Plankton’s absorption of CO2 higher than assumed

A study into the chemical composition of marine plankton is challenging a long-held assumption on how much carbon dioxide the organisms consume.

The study, published online Sunday in Nature Geoscience, calls into question the textbook ratio of carbon, nitrogen and phosphorous contained in all plankton. This so-called “Redfield ratio,” named for oceanographer Alfred Redfield, holds that those compounds are fixed at 106:16:1 units respectively.

However, after examining over 700 ocean water samples from the North Atlantic, the Bearing Sea, the Carribean and other locations, researchers found that the chemical composition varied widely according to temperature, and global lattitude.

Warm waters had a far higher ratio of CO2, rising to as much 195:28:1, while cooler seas had ratios that fell to 78:13:1

The finding may prompt a revision of some climate warming forecasts, as carbon dioxide is a primary factor in climate change. The more carbon dioxide that exists in the atmosphere, the more heat energy gets trapped.

“The Redfield Concept remains a central tenet in ocean biology and chemistry,” wrote lead author Adam Martiny, an associate professor of Earth System Science and ecology & Evolutionary biology at UC Irvine. “Instead, we show that plankton follow a strong latitudinal pattern.”

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