A new study from Plymouth Marine Laboratory analyzed satellite data from 1997 to 2018 and found a steady decline in microalgae primary production across the north-east Atlantic, including the North Sea, Irish Sea, and western English Channel. The drop is linked to warming surface waters and stronger thermal stratification, which limits the mixing that brings nutrients to the surface for phytoplankton. This matters because phytoplankton form the base of the marine food web and play a key role in the ocean's ability to absorb carbon dioxide. A sustained decline could weaken the ocean's natural carbon sink and affect fish stocks. The study also found that the timing of the spring bloom has shifted earlier in some areas, which could disrupt the food supply for fish larvae.
