OceanCANDY members Ben Fisher and Lewis Wrightson (visiting scholar) co-authored a recent paper in Limnology & Oceanography. In work jointly led by Kendra Turk-Kubo, Claire Mahaffey and Jo Hopkins, they report on nitrogen fixation rates in the North Sea and the presence of the nitrogen fixing Braarudosphaera /UCYN-A. Nitrogen fixation has typically been considered unique to the oligotrophic subtropical regions, however this study demonstrates the potential importance of nitrogen fixation in fuelling an estimated 4-24% of summertime productivity in nitrate deplete shelf sea systems following the spring bloom.

This work was completed as part of the NERC funded Nitrogen Fixation in the Arctic (N-ARC) project (PI: Claire Mahaffey). Ben and Lewis conducted nitrogen uptake rates onboard the RRS Discovery, DY167 in July/August 2023. 

Turk-Kubo, K., Mahaffey, C., Hopkins, J., Hawley, R., Norman, L., Wrightson, L., Fisher, B., Rynders, S., Neil, C., Ilyas, M. and Lohan, M.C. (2026), High nitrogen fixation and Braarudosphaera presence in the North Sea. Limnol Oceanogr, 71: e70331. https://doi.org/10.1002/lno.70331