BMLSS Crabs of the Seashore
Most of Shoreham Beach is shingle giving way to sand which is visible at low tide. Groynes prevent longshore drift from the west.
In the entrance to Shoreham Harbour, there are artificial rocky* shores at Kingston Beach near the Lighthouse, and at the Old Fort beach on the other side of the River Adur. (* Larvikite, a type of syenite). These new rock groynes have now been extended the full length of Shoreham Beach and as far as Lancing Beach Green (May 2003).
At Kingston Beach there are extensive mussel beds, with lots of periwinkles, although a spate of over-collection during the 1980s decimated the beds and Serrated Wrack has now established itself, because of the reduction of the grazing molluscs.
INTERTIDAL WILDLIFE REPORTS
Zonation on the Shore
Longshore drift occurs as a result of wave action. Propelled by the dominant south-west winds1 the wave (the swash) hits the shingle beach and moves the pebbles obliquely up the shore and the backwash returns the pebble at right-angles, the following waves repeating the process so that the pebbles gradually move along the shore. The larger pebbles are to be found higher up the beach as the swash is more powerful than the backwash. On Shoreham Beach the Environmental Agency interfere with the natural process by moving large amounts of shingle back to where they were washed away from, to protect the housing developments on the foreshore.
prevailing winds over Britain are from the south-west. These propel the
waves on to the shore on both sides of the English Channel. However, on
other coasts the prevailing winds blow out to the sea and the dominant
waves that crash on to the shore come from other directions, e.g. from
the north-east on the North Sea coasts, causing longshore drift from north
Local Wildlife Links (SE England)
Valley Nature 2007