Research from the Massachusetts Institute of Technology (MIT) suggests that planktonic stocks in the subarctic Atlantic have been declining steadily over the past 200 years in response to climate forcing.
In a paper published today in Nature, Matthew Osman, the paper’s lead author and a graduate student in MIT’s Department of Earth, Atmospheric, and Planetary Sciences and the MIT/WHOI Joint Program in Oceanography, tracked the decline by measuring the levels of a substance called methanesulphonic acid or MSA, in ice cores from Greenland.
Phytoplankton blooms put chemicals into the atmosphere, some of which decay into MSA which is subsequently deposited across the region on land and sea. When locked in layers of ice, these chemicals produce a unique record of phytoplankton productivity over time.
The MBA's David Johns said: "This recent article uses CPR phytoplankton data from 1958 to 2016 from the subarctic Atlantic that corroborated Osman’s findings. Our US colleagues found a decline in phytoplankton productivity in the northern Atlantic, and linking our data with ice core data, show this decline is linked to changes in ocean temperature and ocean currents, and coincides with the increase in industrialisation. Worryingly, the research looks ahead and predicts further productivity declines linked to climate change and the associated variations in circulation patterns. This type of work is greatly supported by consistent, spatially extensive datasets, and the CPR survey is unique in offering this."
Read the MIT press release.