Shoreham Beach

Had a look at Shoreham Beach to see if there were many stranded starfish and what else I could find of interest on the strandline.

There were very few starfish present. Mainly bits of larger ones, especially single legs. There were a quite a few dogfish egg case but only two ray egg cases. Only one of these was intact and possible to identify. It was from an undulate ray. The egg felt heavier than the empty cases and smelt. I carefully cut it open to reveal a partly developed ray with egg yolk. The embryo had started to dry. (see below)

It was interesting to see the number of pebbles with holes on the beach. It took a lot of searching last month to find a few for a display, today they were everywhere. We now call thgem lucky stones but were originally refered to as hagstones and where reputed to be a protection again witches. Here are just a few of the hagstones I found on a short stretch of beach.

Beachcombing after the gales

First chance to check out the beach following the severe gales recently. We went to Southwick Beach first starting at Carrots Cafe along to the eastern arm of Shoreham Harbour.


We walked to the end of the harbour arm where a couple of fishing boats chugged along underneath a cloud of seagulls wheeling overhead. Within the harbour mouth a great crested grebe dived periodically beneath the water. Not a common bird in this area but I have noticed reports over the years of Great Crested Grebe on the sea at Shoreham.



On the way back to the car we explored the strandline. The most common strandline objects were the clumps of whelk eggs. Usually washed ashore after the eggs had hatched, due to the stormy seas some of the egg capsules still had eggs. There were also large piles of slipper limpet shells that had been washed up together. There was also a dead spider crab and numerous dead starfish amoungst the debris.
There were numerous empty dogfish eggcases and a few ray egg cases (Dogfish egg case below)

We also found about a dozen scallop shells (below) and several oyster shells, the latter had both halves (valves) still intact.
Afterwards we drove along the coast to Hove beach for a hot drink and to further explore the strandline. My wife Sharon and our friend Xena had visited this beach yesterday and said there was lots to see.
There were many slipper limpet shells on this beach as well. I also found a stack of live slipper limpets, 5 stuck together in a stack.

The bottom slipper limpet is a female the rest are males. If the female dies, for example if they are dislodged in a storm, the next male will change sex and become female. Unlike the common limpet, slipper limpets are plankton feeders.

There were also numerous whelk eggcases here too (see above). A few dogfish eggcases and a larger number of ray eggcases (see below), 14 which I found on just one area of the beach.

I found the remains of a small sea urchin (below). Not an empty test (this is what the shell is called) unfortuantely but the dead remains with the spines missing. If you look carefully at the image below you will notice the tube worm on the slipper limpet shell, top left.

The other unusual find was a clump of eggs about 10 cm across. The nearest thing I had seen to this is lumpsucker fish eggs. The female lumpsucker lays her eggs close to shore and leaves them to be guarded by the male.

Beachcombing

After the recent stormy weather its the idea time for a spot of beach combing. While the timber washed ashore has been a major news item, there is far more of interest to look for amongst the seaweed and other debris. Here are a few of my finds.

The beach is covered in numerous cream coloured balls that resemble bubble wrap and are often mistaken for sponges. These are the egg mass of the common whelk, often referred to as sea wash balls as they were used by early sailors to wash. Each of the smaller capsules contains thousands of eggs, but only about 10 hatch the remaining are eaten by their siblings. This may seem wasteful, but in fact the few that do hatch have had a hearty meal and increase their chances of survival. Several female whelks will often lay their eggs together creating quite large egg masses. When cast up after a storm, the whelk egg masses may still contain viable eggs.

The occasional weathered and empty common whelk shell are also present amongst the seaweed. Most are broken to some degree, making the intricate internal structure visible. This one was intact. These whelks are carnivorous, feeding on marine worms and other molluscs such as bivalves (which have two halves to their shell). Whelks can use the edge of their own shell to prize open bivalve shells to feed on them. Common whelks also feed on dead animals, which they locate by smell using their siphon. They wave the siphon back and forth to detect where the smell of food is coming from. Empty shells such as this one are sometimes used as a temporary home by hermit crabs as these crabs have no protective shell on their abdomen.

These dark coloured egg cases belong to rays, a relative of sharks. In contrast to the whelk eggs, these egg cases contain a single embryo. The capsules hatch after 5 or more months (depending on the species). Several UK species of ray have greatly declined over the last few decades. The Shark Trust are collecting records of ray egg cases on the beach to help locate nursery grounds to better protect UK species so they have a chance to recover. If you find a ray egg case the records should be sent to the Shark Trust, http://www.eggcase.org/
A couple of years ago I worked with Brighton based River Ocean Foundation as Education Coordinator for a project called Ocean 2. As part of this project I worked on a strandline exhibition that was set up at the Booth Museum of Natural History also in Brighton. The exhibition was made up of various displays that focused around the seashore strandline. These included a replica beach, the forces that created the strandline, scavengers, myths and folklore, beach object identification, amazing eggs, marine litter, stranded sea mammals and more. When the exhibition came to an end, River Ocean Foundation created a website including images of the exhibits and all the original text I wrote for the exhibition.
To find out more about the strandline you can visit the website at http://www.riverocean.org.uk/ocean/exhibition/digibooth/Strandlinehome.htm