Image of the week: Marine algae bloom in the Black Sea

Phytoplankton are microscopic marine algae that form the basis of marine food chains. They also play a key role in sustaining life on Earth as they are responsible for producing over half of the world’s oxygen and they help regulate the climate as they absorb large amounts of carbon dioxide (CO2) from the atmosphere during photosynthesis.

The bloom (cyan colour in the image) is most likely caused by coccolithophores, which are microscopic single-celled plant-like organisms that live in large numbers throughout the upper layers of the ocean. 

These tiny microscopic plants are covered in an armour plating of white chalk plates, which means that when they form massive blooms of billions of coccolithophores they can turn the sea a milky colour and this can sometimes be seen from space.