The bloom is most likely caused by coccolithophores (cyan colour) and other phytoplankton species. Phytoplankton play a key role in marine ecosystems as the basis of the food chain.
Many aeroplane contrails are also visible in the image over England, the Channel and northern France.
There is also an additional zoomed-in view (below) captured on the same day by the Copernicus Sentinel-2 satellite, showing ships moving north through the bloom area.
