Featured Science Paper
Dissolution dominating calcification process in polar pteropods close to the point of Aragonite undersaturation
Pelagic snails (pteropods) are small shelled planktonic organisms that are common throughout the world’s oceans and play an important role in oceanic food webs. They build their shells from aragonite, a form of calcium carbonate that is particularly sensitive to changes in ocean chemistry. As the surface layers of the ocean become increasingly acidic through the absorption of anthropogenic CO2, pteropods will be amongst the first animal groups to be affected. The precise impact of ocean acidification (OA) on the viability of pteropods has nevertheless been a matter of contention. Some experimental studies have shown that these organisms only have a limited means of protecting themselves and their shells start to dissolve when waters become corrosive to aragonite. However, other studies have demonstrated that they can keep growing their shells under such conditions.
The present study examined how the ability of pteropods to keep building their shells compared to the rate at which their shells dissolved under various future OA scenarios. We found that, although offsetting some loss of aragonite from the shells, pteropods were not capable of compensating for the effect of dissolution, even in OA scenarios predicted to be widespread in the Southern Ocean in 40 years time. Pteropods in polar regions are major contributors to the passage of carbon to the ocean interior, which partially offsets industrial emissions of CO2. The dissolution of their shells not only impacts their own viability but also a globally important natural process of carbon mitigation.
Link to the full paper in the NERC Open Research Archive
Authors
Bednaršek, N., Tarling, G. A., Bakker, D. C., Fielding, S., & Feely, R. A. (2014)
Publication
PloS one, 9(10), e109183
