Rocky shores are rich in marine biodiversity, with an impressive range of species occupying the different marine zones down the shore. As a fully marine environment, the sublittoral zone can sustain a wide variety of species. Many of the species inhabiting the intertidal zone are specifically adapted to be able to live both in and out of the sea, and therefore cannot be found elsewhere .
Biodiversity generally decreases further away from the sea, with only a few species of lichen being able to survive on rocks in the splash zone. Marine plant material deposited in strandlines, however, provides important habitat for small invertebrates and birds further away from the sea.
Although rarely seen and often considered a freshwater species, the common otter (Lutra lutra) forages for fish on rocky coasts in the UK . Both of the UK’s seal species, the common seal (Phoca vitulina) and the grey seal (Halichoerus grypus), are also found on rocky shores, diving for fish in the sea or basking, mating or breeding on land . Further out to sea, cetaceans such as the bottlenose dolphin (Tursiops truncatus), harbour porpoise (Phocoena phocoena) and even orca (Orcinus orca) also reside .
Rocky shores provide food for a variety of different native and migratory birds including gulls, waders, terns, eiders and kittiwakes . Oystercatchers (Haematopus ostralegus) prowl the rocky shores looking for limpets, crabs and mussels. Cliff shorelines are used as rest stops and breeding grounds for bird species that dive for fish out at sea, such as the puffin (Fratercula arctica)
Lichens such as Caloplaca aractina and golden hair lichen (Teloschistes flavicans) are found on some of the most inhospitable parts of the rocky shore .
Rocky shores are home to several species of fish, including lumpsuckers, butterfish and goby . The giant goby (Gobius cobitis) can be found in rock pools on the western part of England’s southern coast .
Rocky shores support a vast number of marine invertebrate species, including crustaceans such as the edible crab (Cancer pagurus) and the common prawn (Palaemon serratus) , both of which can be found in rock pools across the UK . Anemones, starfish, sea urchins and sea slugs such as the sea lemon (Archidoris pseudoargus) can also be found all over rocky shores .
In addition to this, the strandlines of marine vegetation provide food and habitat for a large number of terrestrial invertebrate species
Rocky shores are able to sustain a large collection of seaweeds and kelps which are not able to anchor themselves in more sandy habitats . Bladder wrack (Fucus vesiculosus) is one of the more recognisable seaweed species, and is a common sight along the coast . Further inland, terrestrial plants such as rock sea-lavenders (Limonium spp.) and sea beet (Beta vulgaris) are able to thrive in a highly saline environment .
Explore the biodiversity of UK rocky shores: