Acidified ocean water found along US West Coast

A study of the California Current System has found highly acidified water along the US West Coast.

The study led by Francis Chan, a marine ecologist at the Oregon State University (OSU), said conditions will continue to worsen due to the atmospheric carbon dioxide primarily to blame for the increase in acidification has been rising substantially, Xinhua news agency reported.

While findings of the study, which was published in the Nature Scientific Reports, identified "hotspots" of pH, or potential of hydrogen, measurements as low as any oceanic surface waters in the world, there were "refuges" of more moderate pH environments that could become havens for some marine organisms to escape more highly acidified waters.

"The threat of ocean acidification is global and though it sometimes seems far away, it is happening here right now on the West Coast of the US and those waters are already hitting our beaches," Chan said on Sunday.

"Ten years ago, we were focusing on the tropics with their coral reefs as the place most likely affected by ocean acidification. But the California Current System is getting hit with acidification earlier and more drastically than any other locations around the world."

With a network of sensors to measure ocean acidification along 965 km of the West Coast, the researchers observed near-shore pH levels that fell well below the global mean pH of 8.1 for the surface ocean over a three-year period, and reached as low as 7.4 at the most acidified sites, which is among the lowest recorded values ever observed in surface waters.

Previous studies have documented a global decrease of 0.11 pH units, equivalent to a drop of approximately 30 per cent, in surface ocean waters since the beginning of the Industrial Revolution.

Highly acidified ocean water is potentially dangerous because many organisms are very sensitive to changes in pH.

The researchers have noticed that negative impacts already are occurring in the California Current System, where planktonic pteropods, or small swimming snails, were documented with severe shell dissolution.

--IANS

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