The BBC reports that
Scientists from the Arctic Monitoring and Assessment Programme (AMAP) monitored widespread changes in ocean chemistry in the region.
They say even if CO2 emissions stopped now, it would take tens of thousands of years for Arctic Ocean chemistry to revert to pre-industrial levels.
Many creatures, including commercially valuable fish, could be affected.
They forecast major changes in the marine ecosystem, but say there is huge uncertainty over what those changes will be.
The report is here [pdf]. In particular it asserts that
Owing to the large quantities of freshwater supplied from rivers and melting ice, the Arctic Ocean is less effective at chemically neutralizing carbon dioxide’s acidifying effects, and this input is increasing with climate warming. In addition, the Arctic Ocean is cold, which favors the transfer of carbon dioxide from the air into the ocean. As a result of these combined influences, Arctic waters are among the world’s most sensitive in terms of their acidification response to increasing levels of carbon dioxide. The recent and projected dramatic decreases in Arctic summer seaice cover mean that the amount of open water is increasing every year, allowing for greater transfer of carbon dioxide from the atmosphere into the ocean.