Infralittoral zone

Part of the coastline always covered by the sea. It extends from the intertidal zone to the open sea, until the depth of the water becomes too great to allow the penetration of light.

Space between the lowest tide limit (low water spring tide mark) and the limit compatible with the life of flowering sea plants (sea grasses) and multicellular algae, about a few tens of meters deep. This zone is colonised by organisms that require continuous immersion.