Major study of ocean acidification helps scientists evaluate effects of atmospheric carbon dioxide on marine life

UC Santa Barbara Office of Public Affairs: Might a penguin's next meal be affected by the exhaust from your tailpipe? The answer may be yes, when you add your exhaust fumes to the total amount of carbon dioxide lofted into the atmosphere by humans since the industrial revolution. One-third of that carbon dioxide is absorbed by the world's oceans, making them more acidic and affecting marine life.

A UC Santa Barbara marine scientist and a team of 18 other researchers have reported results of the broadest worldwide study of ocean acidification to date. Acidification is known to be a direct result of the increasing amount of greenhouse gas emissions. The scientists used sensors developed at Scripps Institution of Oceanography at UC San Diego to measure the acidity of 15 ocean locations, including seawater in the Antarctic, and in temperate and tropical waters.

As oceans become more acidic, with a lower pH, marine organisms are stressed and entire ecosystems are affected, according to the scientists. Gretchen E. Hofmann, an eco-physiologist and professor in UCSB's Department of Ecology, Evolution & Marine Biology, is lead author of the recent article in PLoS ONE that describes the research.

..."The emerging pH data from sensors allows us to design lab experiments that have a present-day environmental context," said Hofmann. "The experiments will allow us to see how organisms are adapted now, and how they might respond to climate change in the future."

....The researchers found that, in some places such as Antarctica and the Line Islands of the South Pacific, the range of pH variance is much more limited than in areas of the California coast that are subject to large vertical movements of water, known as upwellings. In some of the study areas, the researchers found that the decrease in seawater pH being caused by greenhouse gas emissions is still within the bounds of natural pH fluctuation. Other areas already experience daily acidity levels that scientists had expected would only be reached at the end of this century.....

UCSB graduate student Emily Rivest positions a SeaFET pH sensor in a coral reef off the island of Moorea, in French Polynesia. TThe reefs surrounding the island of Moorea are home to UCSB's Coral Reef Long-Term Ecological Research site (MCR LTER). Credit: Anderson Mayfield