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.
After the beach boulders and scattered rusty metal debris, there is sequence of flat rock platforms exposed by the retreating water. They are riddled with holes made by the boring bivalves known as piddocks, some burrows just have empty shells in them but others are still occupied by the living molluscs that squirt water a foot or more into the air at frequent intervals. A velvet swimming crab mooches around the edges of the platforms, and sand tube and mud tube dwelling worms abound on all the surfaces.
I discovered an interesting stretch of shoreline when I visited Lyme Regis yesterday. The cliff location is known as The Spittles and it is situated immediately east of the new sea wall. The tide was going out but not as far as in March 2010. Enough to disclose an array of boulders with scattered fossils, broken coloured glass, and rusting metal. The man-made junk resulted from a major landslide in 2008 when the contents of an old town rubbish tip (which had been in existence from 1920 to 1973) cascaded shore-wards with the rocks and mud. The junk continues to wear out of the cliff face to the present time.
There are some interesting items to be found. The rusting metal components, often with remnants of paint, provide intriguing contrasts with the natural environment in which they are lodged. There is a striking similarity between the metal colours and textures and those of the dead and dying autumnal colours of seaweed. As the water receded, it left intricate patterns in the sand around the rocks and even in fine sediments of smoother rock surfaces.
The tide went out a long way on 10th March 2012. A very long way. For the first time ever I was able to see the glory of the hitherto hidden acres of golden-fronded kelps, brown fucoids, and red seaweeds carpeting the rocks at Lyme Regis. Usually when I visit the water is high on the shingle beach but on this occasion I could follow the water as it went out over the sand and rocks to get an entirely new perspective by looking up the shore, to the Cobb, the town, the fossiliferous cliffs of Black Ven and Charmouth to the east, including sight of Golden Cap. I didn’t know it at the time but this was the last time I was going to see the old breakwaters at Church Cliff.
This was almost the last time that I saw the old sea wall and breakwaters at Church Cliff in Lyme Regis. As part of a scheme to improve the sea defences in Lyme Regis, the breakwaters were demolished a few years later and the old sea wall, as it was seen in these images, disappeared from sight and was replaced by a stronger structure more fit for purpose and providing additional amenity value. I was surprised how different these shots were from the earlier ones from 2010. The tide was in and covering seaweed and cobbles, the light was different and had a big impact on the colours observed, and it was a different camera and that had an effect too.
The main sea defence structure at Church Cliff in Lyme Regis back in 2010 and 2011 was a concrete sea wall. This was built into the base of a cliff that is made of soft slipping strata. It was from the sea wall that the iron and wood breakwaters jutted out at right angles to deflect the impact of the sea. The concrete wall in part held back the cliff and in part prevented undercutting by the waves. Over time the wall had become stained by run-off from above and by lichen and bacterial deposits to form interesting striped patterns with subtle variations like an almost monochromatic natural abstract art along the length of the wall. This wall has since been replaced by a much stronger structure, along with the demolition of the breakwaters.