Siberian erosion, river runoff speed up Arctic Ocean acidification

http://www.adn.com/article/20160424/siberian-erosion-river-runoff-speeds-arctic-ocean-acidification

As Siberian permafrost thaws, crumbling Russian coastlines and big rivers flowing north along eroding banks are dumping vast loads of organic carbon into marine waters there, causing much quicker acidification than had been anticipated and signaling future danger for the entire Arctic Ocean.

So says a newly published study by a team of scientists from the University of Alaska Fairbanks, the Russian Academy of Sciences and other institutions in Russia and Sweden. The scientists have been working together for years to study the East Siberian Arctic Shelf, a marine area that accounts for about a quarter of the Arctic Ocean’s open waters.

Observations made since 1999 showed signs that in some locations, acidity has already surged past levels researchers didn't expect to emerge until the year 2100, due in part to "extreme aragonite undersaturation," the study says.

Aragonite is a form of calcium carbonate that is pervasive in the ocean and tilts the chemistry toward the base level of the pH scale. Carbon in the water tilts the pH scale toward the acid level. The degree to which the water is saturated with aragonite is a marker of overall calcium levels -- and a marker of acidification caused by increasing loads of carbon in the water, according to NOAA.