A shingle beach is a harsh environment; waves roll the stones about, scraping them together and crushing seaweeds and animals. Higher up the beach, beyond the high water mark, plants colonise areas where shingle was thrown up by waves. Although there is little soil and freshwater there, sea kale, (a wild cabbage), bright blue viper's bugloss, pink sea bindweed and many other plants thrive. In spring, terns and plovers lay their eggs on the shingle; the patterns on the eggs camouflage them from predators such as gulls, kestrels and foxes.

A rocky shore is a wild place to explore at low tide, but tread carefully, it is all too easy to slip or damage marine life. Sheltered rocky beaches support a rich diversity of life, with seaweeds and animals living near low water levels being different to those found around the high water levels. For simplicity, ecologists divide a rocky shore into four zones, each defined by relative time of submergence by tides.

The 'splash zone' is rarely flooded by tides and the maximum spread of sea spray can be gauged from the extent of black lichen covering the rock. Few shore species survive there, including rough and small periwinkles as well as the sea slater, which resembles a large woodlouse. These species are also found on the upper shore, below the splash zone.

The 'upper shore' floods only at mean to extreme high water spring tides, but channelled wrack (seaweed) is common, and its blackened dried-up strands rehydrate quickly when submerged. The water in rock pools on the upper shore becomes hot on sunny days and saltier as water evaporates. However, when it rains the water is diluted, decreasing salinity. Only seaweeds, sea lettuce, the filamentous Enteromorpha, and a few animals (such as beadlet sea anemones and small crustaceans) can survive such extremes.

The 'middle shore' contains rocks covered with limpets, which graze on algae; other rocks are covered by barnacles. Their shells open at high tide and their limbs emerge, making grabbing movements to collect plankton.

Groups of mussels tie themselves to rocks by special 'byssus' threads. Both barnacles and mussels have free-swimming larvae, which swim with plankton for a few weeks, until they settle on rock surfaces and become attached, where they are prey for fish and dog whelks. Brown seaweeds, spiral, bladder and knotted wracks may blanket the middle shore. The slimy feel of seaweeds derives from the jelly-like mucilage that protects them from drying out at low tide. Look under fronds of seaweed to find brightly coloured flat periwinkles, painted top shells, and crabs sheltering there. Top shells and periwinkles are marine snails, which breathe by gills that extract oxygen from seawater; the gills are closed off at low tide.