Red Sea Fan

Photo: Frédéric ANDRE · CC BY-NC

Red sea fans form the structural centrepiece of the Los Gigantes Wall below 20 metres, their branching colonies reaching up to a metre across on stable rock faces where prevailing current direction allows optimal plankton capture and where sediment load is low enough to prevent smothering of the polyps. As long-lived structural species — individuals can exceed 100 years — they are considered biological sentinels for the health of the northeastern Atlantic marine environment, and their presence in good density on the Los Gigantes Wall reflects both the water quality of the upwelling zone and the relatively low physical disturbance of this remote cliff coastline. Each colony provides habitat for multiple associated species including the Mediterranean feather star, brittle stars that drape across branches to filter-feed in the current, and small fish that use the colony's structure as refuge from predators and spawning aggregation sites.