Ascophyllum nodosum with epiphytic sponges and ascidians on
variable salinity infralittoral rock Ecological and functional
relationships The biotope is found in very shallow submerged
rocky habitats in lagoons, subject to variable or permanently
reduced salinity conditions. These particular habitat conditions
lead to a variety of seaweed-dominated communities which include
fucoids and green filamentous species. The fucoids, more typical
of intertidal habitats, penetrate into the subtidal under the
reduced salinity conditions which are not tolerated by kelps.
The biotope is dominated by dense stands of Ascophyllum nodosum.
The species, and the other macroalgae in the biotope, increase
the amount of space available for attachment, they provide
shelter from wave action, desiccation and heat, and they are an
important food source. High abundances of the characterizing
algae may contribute to the oxygen budget of lagoons. In the
North Atlantic for example, Ascophyllum nodosum is of great
ecological importance beca