Study warns of ocean acidification effects

• Tweet

EDINBURGH, Scotland, March 29 (UPI) -- British researchers say ocean acidification, the result of increasing levels of atmospheric carbon dioxide, could significantly affect marine ecosystems.

Newcastle University scientists say they performed experiments in which they simulated ocean acidification and found the decrease in ocean pH (increased acidity) resulted in a sharp decline of a biogeochemically important group of bacteria known as the Marine Roseobacter clade.

"This is the first time that a highly important bacterial group has been observed to decline in significant numbers with only a modest decrease in pH," said postgraduate researcher Michael Maguire.

The Marine Roseobacter clade, the scientists said, is responsible for breaking down a sulfur compound that's produced by photosynthesizing plankton. This end product is taken up and used by numerous bacteria as an important source of sulfur, the researchers said.

A fraction of the sulfur compound is turned into dimethylsulfide -- a naturally occurring gas that encourages the formation of clouds that reflect solar radiation back into space leading to a cooling of the Earth's surface.

The scientists hypothesize the decline of the Marine Roseobacter clade through ocean acidification might alter the release of dimethylsulfide into the atmosphere and affect the amount of available sulfur. That, they said, will have a significant impact on the ocean's productivity and the overall global climate system.

The study is being presented this week in Edinburgh, Scotland, during the spring meeting of the Society for General Microbiology.