Phytoplankton blooms in the North Sea tend to be most abundant in late spring and early summer due to high levels of nutrients in the water and increased sunlight.
Conditions are ideal with the intense winds blowing over the relatively shallow sea bringing nutrients to the surface to combine with run-off from European rivers.
But now, sSome researchers have found that numbers of plankton can actually begin to increase in the middle of winter, when growth conditions would seem to be at their worst.
Studies suggest that winter storms churn the ocean and cause deep water mixing. This water mixing allows for phytoplankton to grow and live at depth without being spotted by their predators.
When spring arrives, phytoplankton can fully bloom because not only are the nutrients available, but there is a longer period of sunlight
The image above, acquired in June by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite, shows a mass of phytoplankton blooming between Denmark, the United Kingdom, and Germany.