Aragonite Undersaturation in the Arctic Ocean: Effects of Ocean Acidification and Sea Ice Melt

Abstract

Acidic Ocean One consequence of the historically unprecedented level of CO 2 in the atmosphere that fossil fuel burning has caused, in addition to a warmer climate, is higher concentrations of dissolved CO 2 in the oceans. This dissolved CO 2 makes the oceans more acidic, and thus less saturated with respect to calcium carbonate. This has important ramifications for organisms that have calcium carbonate skeletons, which depend for their survival on the saturation state of calcium carbonate in the waters where they live. Yamamoto-Kawai et al. (p. 1098 ) report that in 2008, surface waters of the Canada Basin became undersaturated with respect to aragonite, a relatively soluble form of calcium carbonate incorporated into the shells or skeletons of many types of marine plankton and invertebrate. This undersaturation occurred much sooner than had been anticipated and has important implications for the composition of the Arctic ecosystem.