Structures such as the sea wall, pool enclosure, boat mooring stakes, chains and slipways all have their own communities, often dominated by small species of algae but also lichens. Lichens are not easy to identify, they are a symbiosis of algae and fungi, most of which do not like being underwater. Their distribution is determined by a combination of tide height, splash reach and a suitable substrate with limited erosion. Mites and other tiny invertebrates use the more textured species for shelter. Sea slaters, bristletails and springtails are all residents in these areas, some of these are extremely active on sunny days, others prefer the cover of darkness. These, in turn, provide food for the rock pipet, wagtails and various corvids (crows). If these features are close enough to the high tide mark they will hold, small and rough periwinkles in cracks and crevices, these species can tolerate long periods out of the water and graze on the biofilm (microscopic thin layer of living material) that covers this zone.
Man-made features are always worth checking they can hold species that cannot find suitable homes elsewhere.
Man-made features are always worth checking they can hold species that cannot find suitable homes elsewhere.