Sand and mud is produced by years of erosion. When the tide is out, inhabitants of the sandy shore have to beat a hasty retreat and find shelter away from the sun, the wind (drying out is their biggest problem) and hungry predators. Because of this, most sandy shore creatures wisely live beneath the surface of the sand! But a close look will provide signs of life:

sandy shore factfile

• One of the most common seashore inhabitants, the lugworm, leaves a telltale sign in the form of the familiar worm cast. A small hole just a few inches away is the other end of its U-shaped burrow.
• Bivalve molluscs, such as tellins, have hard shells and use a powerful muscular foot to pull themselves into the damp sand. When the tide comes in, the tellin extends its siphons into the water, taking in plankton rich water through one siphon and ejecting the waste through a second.
• action alert: Always follow the MCS Seashore Code, and take part in projects like the annual MCS Beachwatch beach survey and clean-up campaign.

  In some areas, particularly the west of the UK and in deeper waters, sea cucumbers play an important role in processing sand in a similar role to earthworms in garden soil. The cucumber. a relative of starfish and urchins. consumes sand. digests food particles from it. and then ejects the clean sand.
• The heart urchin or sea potato also lies buried in sand. An echinoderm just like the starfish and sea cucumber. its tube feet pick up food particles. and small spines help dig the animal in.