Razorshells on a Norfolk beach, washed up after a winter storm.
Beloved of holidaymakers, sandy shores also have much to offer the visiting naturalist. Beneath the surface of the sand lives an abundance of marine worms and molluscs, whose presence would go largely undetected were it not for the feeding activities of birds and the profusion of dead shells found along the strandline.
MARINE LIFE OF SANDY SHORES
Although the shells of marine bivalve molluscs are commonly washed up on the shore, in life they are much harder to find. Typically, they live buried in the sand and open their shells to reveal their feeding siphons only when covered by water and undisturbed. At low tide you would never know they were present, let alone in such numbers, although keen-eyed observers can sometimes spot a slight depression in the sand below which lies a mollusc.
In addition to the molluscs that live largely buried on the sandy shore, a range of other invertebrates also make a living here. Prawns are often abundant, as are Shore Crabs, both of which rely on camouflage and partial burial in sand to avoid detection by predators. Burrowing starfish and sea urchin species also live here and flatfish are usually common.
Razorshells on a Norfolk beach, washed up after a winter storm.
BIRDLIFE OF SANDY SHORES
Outside the breeding season, look for Sanderlings as they follow the line of breaking waves in search of small invertebrates. Black-headed Gulls are always in evidence along the shoreline. Offshore, fish and crustaceans provide a rich supply of food for those bird species that are sufficiently well adapted to catch them. During the summer months, terns can be seen plunge-diving here, while in winter grebes, Red-throated Divers and seaducks may exploit this resource.
SAND DUNES
On the landward side of a sandy beach, colonising plants – notably Marram, the classic dune grass species – establish stable dune systems. Subsequently, these are colonised by maritime plants such as Sea Spurge, as well as grassland species such as Viper’s-bugloss and Common Bird’s-foot Trefoil. Stable dune systems offer potential for birds such as Ringed Plovers and terns to nest. Sadly, however, human disturbance effectively excludes these species from almost all suitable areas in southern England.
Sea Spurge is a distinctive and characteristic member of the sand-dune community of plants.
Shingle is a challenging environment for any plant or animal, as by its very nature it is unstable, incredibly free-draining and lacking anything that resembles conventional soil. Despite this, a few plant species are hardy enough to survive here. Indeed, specialists such as Sea-holly, Yellow Horned-poppy and Sea-kale are seldom found anywhere else.
Contrary to all expectations, a surprising number of invertebrates manage to live among the pebbles that comprise a shingle beach. Many feed on the small amount of detritus that accumulates in the interstices close to the high-tide mark.
Shingle beaches also offer opportunities for nesting birds, including waders, terns and gulls. Inevitably, however, human disturbance excludes them from most sites in the south, except where the birds are afforded special protection. Nesting colonies are generally more successful in more remote, northern locations.
The Scaly Cricket Pseudomogoplistes vicentae is confined to a handful of coastal shingle beaches in Britain and the Channel Islands; it lives in the interstices and feeds on detritus.
Hutchinsia Hornungia petraea is very locally common on south-facing dunes along the south Wales coast. It is a member of the cabbage family and an early flowerer, often in bloom in late February.
Sea-holly growing on a shingle beach on the Hampshire coast.