Life in the sea can be divided into three most important zones:

LITORAL - coastal area,
PELAGIAL – zone of free water
BENTOS – living world from the bottom of the sea

Coastal seas make up only 10% of the total surface of the world's seas and oceans, but 90% of all marine species live on this narrow strip, including marine primary producers, algae and cyanobacteria. 

Primary producers support almost all marine life by producing the oxygen and food they need. Directly or indirectly, all life on Earth depends on primary producers and the sea coast.

Underwater meadows, where a variety of species thrive, play a special role in these processes.