Marine phytoplankton have a crucial role in the modulation of marine-based food webs, fishery yields and the global drawdown of atmospheric carbon dioxide3. However, owing to sparse measurements before satellite monitoring in the twenty-first century, the long-term response of planktonic stocks to climate forcing is unknown.

We show that the initiation of declining subarctic Atlantic productivity broadly coincides with the onset of Arctic surface warming, and that productivity strongly covaries with regional sea-surface temperatures and basin-wide gyre circulation strength over recent decades. Taken together, our results suggest that the decline in industrial-era productivity may be evidence of the predicted collapse of northern Atlantic planktonic stocks in response to a weakened Atlantic Meridional Overturning Circulation. Continued weakening of this Atlantic Meridional Overturning Circulation, as projected for the twenty-first century, may therefore result in further productivity declines across this globally relevant region.

The study was conducted by Matthew B. Osman et al.

Industrial-Era Decline in Subarctic Atlantic Productivity