The rock ledges below the new sea wall at Church Cliffs in Lyme Regis, Dorset, are the upper strata of the Blue Lias limestone. The natural limestone ledges and the smooth artificial substrate of the concrete sea wall, provide a home for numerous seashore creatures like limpets, winkles, and top shells as well as many commonly attached red, green and brown seaweeds, and encrusting calcareous algae (pink Lithamnion). The brown substance sticking to a lot of limpet shells is also an encrusting seaweed (probably Brown Limpet Paint Ralfsia verrucosa).
Multitudes of small holes penetrating the rocks are the often-occupied burrows of small marine polychaete worms like the Polydora species. Occasional drifts of sandy ripples coating the stone are punctured by largish round holes where bivalved burrowing piddocks living in the rocks below have squirted jets of water from their exhalent siphons and cleared the sand away.
It is interesting to see that the seashore life is equally at home on the old concrete footings from the defunct breakwaters as it is on the limestone.
The shore beneath the new sea wall in Lyme Regis looks very different now the old breakwaters or groynes have been removed. You can still see the linear concrete footings of the old wood and iron structures but most of the pebbles and cobbles that used to accumulate between the walls are now absent (at least for the moment). A bare rock pavement is revealed, comprising a series of steps representing the strata and colonised by seaweeds. Rippled sand sometimes deposits in the valleys between the rock ledges.
Some of the things that caught my eye as I walked along the beach at Studland in Dorset, England, included interesting beach stones; stranded clumps of red, green, and brown seaweeds; an empty shell of a clam just eaten by a bird; and tubes of Sand Mason Worms.
Warm weather, blue skies, and hazy sun bring out visitors to enjoy the Dorset Coast in England. The milky waters of the sea at one location take on many shades of blue from navy to torquoise. Tranquil waves, lapping gently on the black and white pebbles of the beach, create natural abstract patterns of reflection. While people in leisure craft of all descriptions from motor boats, yachts, and dinghies to kayaks, take full advantage of the lovely day, and revel in the sparkling waves.
This really is a square rock pool. It is one of several to be found on the rock ledge at the foot of the cliffs at Winspit in Dorset. These square pools are scattered amongst the more usual and variously shaped pools on the rock ledge. All the pools are lined with a continuous coating of pink or bleached white calcareous algae. They are fringed with red Coral Weed or green Gutweed and provide a home to an assortment of gastropod molluscs and small fish.
However, the square rock pools are man-made and provide evidence for the industrial history of the area. This is the site of a former quarry. The workings are mostly on the cliff top where you can still explore, with care, the cave like excavations. Large blocks of stone were at one time painstakingly hewn from the strata. The rock was too heavy to cart up the hill to the village. So cranes were constructed from old ships timbers and driftwood in order to lower the stone from the cliff top to the ‘beach’ below. Another set of cranes was built on the rock platform at the water’s edge to lower the stone into boats. The square pits were carved to hold the base of the main wooden post for these cranes.
Carts were used for transferring the stone from the foot of the cliff to the edge of the ledge. As you might imagine, this could be a bit tricky on a wet and slimy surface. In fact, this operation could only be undertaken in the summer months when conditions were more favourable. The carts were pulled by two men. To stop the carts slipping, over-turning, or going in the wrong direction and into the sea with the hard-earned cargo, two parallel ruts were carved in the rock to accommodate the wheels – a bit like tramlines. Two sets of these cart ruts can still be clearly seen.
Revision of a post first published 15 November 2009
The majorpart of the beach at Eype is made up from small size shingle and pebble with scattered large boulders that have rolled across the beach from landslips along the cliffs. However, if you walk westwards along the seashore, the number of boulders increases until the far point is entirely rocky shore from the base of the cliff down into the sea. It is on these rocks and boulders between the extremes of tide that the seaweeds grow.
Strangely, not all of the rocks in the intertidal zone are colonised by algae. Seaweed seems to have definite attachment preferences. The large flat rocky surfaces are the most likely habitat to be occupied – as are large boulders that are constantly splashed and frequently submerged at lower levels of the shore. The seaweeds of different types that cover the flat-topped rocks make interesting patchworks of diverse colour and varying textures.
The most common seaweed is the olive-green Toothed Wrack, Fucus serratus, which is actually a member of the brown seaweed group or Phaeophyceae. Bright splashes of colour are provided by shapeless masses of soft green seaweed, probably Gut Weed Enteromorpha intestinalis, which belongs to the Chlorophyceae group. Pepper Dulse, Laurencia pinnatifida, is easily recognised by its wonderful golden hue, although it is actually a red seaweed belonging to the Rhodophyceae. Soft filamentous red seaweeds that are difficult to individually identify are responsible for extensive areas of pink or purple-brown colour; these provide a counterpoint and contrast to the other types of basically green to yellow algae.
Revision of a post first published 7 February 2010