Arctic Ocean Acidifying Far Faster Than Projected as Ice Melts

Acidification of ocean water is just one of the problems associated with climate change. Now, scientists have discovered that the Arctic Ocean is acidifying far faster than projected as sea ice rapidly melts. The findings could have important consequences for the health of the Arctic ecosystem.

Ocean acidification occurs when the pH levels of seawater decrease due to greater amounts of carbon dioxide being absorbed by ocean waters. The more-acidic waters can impact creatures that rely on calcium carbonate shells, such as corals and shrimp. This, in turn, can affect animals that are further up the food chain.

In order to find out a little bit more about the process of ocean acidification, the researchers conducted three years-worth of research cruises in the Arctic. The examined the seawater chemistry at high spatial resolution, collecting data during the expeditions.

Mixing is a huge part of ocean acidification. With more water exposed, more mixing can occur between the seawater and carbon dioxide. This, in turn, causes the oceans to become more acidic. Needless to say, the lack of ice cover in the Arctic can help promote this particular type of mixing.

It's not just the mixing gases that can impact acidification, though. The freshwater melted from sea ice can dilute the seawater. This, in turn, can lower pH values and reduce the concentrations of calcium and carbonate, which are the building blocks of many micro-organism' skeletons and shells. This could greatly affect the growth of these creatures and, in turn, impact animals further up the food chain.

"A remarkable 20 percent of the Canadian Basin has become more corrosive to carbonate minerals in an unprecedented short period of time," said Lisa Robbins, one of the researchers, in a news release. "Nowhere on Earth have we documented such large scale, rapid ocean acidification."

It's likely that tis acidification will continue to increase, as well. Arctic sea ice is continuing to melt as temperatures warm. In addition, carbon dioxide in our atmosphere is still increasing from year to year. This could spell major problems for the Arctic ecosystem in the future.

The findings are published in the journal PLOS One.