“There’s a synergistic effect between increased ocean acidity and natural light”
“It’s clear we are conducting a giant experiment on the planet and we don’t know what we are doing.”
By Stephen Leahy
UXBRIDGE, Canada, May 8, 2012 (IPS)
Without major reductions in the use of fossil fuels, sunlight will kill an unknown number of ocean phytoplankton, the planet’s most important organism, a new study reports this week.
Not only are phytoplankton, also known as marine algae, a vital component in the ocean’s food chain, they generate at least half of the oxygen we breathe.
In the not so distant future, sunlight, the very source of life for phytoplankton, will likely begin to kill them because of the ocean’s increasing acidity, researchers from China and Germany have learned.
“There’s a synergistic effect between increased ocean acidity and natural light,” says Ulf Riebesell of the Helmholtz Centre for Ocean Research in Kiel, Germany.
Riebesell added that it was also possible “phytoplankton could adapt”.
Researchers were surprised to discover that diatoms, one of the most important and abundant types of phytoplankton, fared very badly during shipboard experiments conducted by co-author Kunshan Gao, from the State Key Laboratory of Marine Environmental Science at Xiamen University, Xiamen China.
Previous experiments in labs like Riebesell’s found that diatoms actually did better in high-acid seawater, unlike most other shell- forming plankton. Burning fossil fuels has made the oceans about 30 percent more acidic researchers discovered less than 10 years ago. Oceans absorb one third of the carbon dioxide (CO2) emitted from using fossil fuels.
The good news is this has slowed the rate of global warming. The bad news is oceans are now more acidic and it will get worse as more CO2 is emitted. This is basic, well-understood ocean chemistry. Continue reading