Phytoplankton Primary Production supports most of the marine ecosystem and is highly sensitive to changing environmental pressures. There is much debate about whether marine primary production is increasing or decreasing and what environmental parameters may be driving these changes. We analysed a 21-year time-series of net primary production (NPP) computed from Ocean Colour Climate Change Initiative (OC-CCI) data spanning September 1997-December 2018, focusing on areas of similar phenology, climatology, and annual NPP in the north-east Atlantic Ocean. Across the entire area, NPP increased from 1998 to 2003, followed by a significant decline until 2018. This pattern was predominant in north-western European coastal waters and specific areas of the English Channel, Irish Sea, North Sea and Norwegian Sea, where it was related to changes in sea surface temperature and mixed layer depth.
Tilstone et al. (Fri,) studied this question.