Rockpooling under Worthing Pier (TQ 150 020)

by Chris Everson 1998


MAY 14TH 1998

During the mid-May 'heatwave' I searched under the pier, on a warm thundery morning in the middle of a set of mediocre spring tides, the water receding just past the end of the pier.

As usual the pier piles were alive with Dogwhelks, Nucella lapillus, gorging on the Acorn Barnacles, Semibalanus balanoides, and Mussels Mytilus edulis, that adorn the metalwork. If you look very carefully at mussel shells that have been opened,  you will probably see a tiny round hole, where a Dogwhelk may have spent up to a couple of days boring through with its tooth-like radula. The mussel provides a substantial meal for the Dogwhelk.
 


Patches of Dogwhelk eggs could be found sheltered in the ironwork crevices but not in the same numbers as in February and March.

 Sea Anemones

There were many anemones to be seen with the Snakelocks Anemone, Anemonia viridis, seeming to outnumber the Beadlet Anemones, Actinia equina.  The sea anemone Sagartia troglodytes and its variations were ubiquitous, showing a seemingly unlimited array of colour as their heads and tentacles were observed on the sand surface, although they are firmly attached to rock below the surface.  (see Glaucus 04.04.39-41).
 


A single large specimen of the Plumose Anemone, Metridium senile, was found in one pool, a beautiful white individual, its fine tentacles resembling cotton wool.

Crustaceans

Many tiny Hermit Crabs, Pagurus bernhardus, were found, most housed in topshells with a few in dogwhelk shells, leaving their trail lines on the sandís surface as they go about their busy lives. There were also many small Shore Crabs, Carcinus maenas, as well as one larger individual that must have recently peeled as it was soft as jelly. There was no trace of its cast off shell. One large specimen of the Edible Crab, Cancer pagurus, found wedged into a discarded piece of downpipe,  measured  15 cm across its carapace. A few Hairy Crabs, Pilumnus hirtellus, were found hiding under some of the less disturbed rocks.
 


Smaller crustaceans observed included a  number of prawns, Palaemon sp. in the pools as well as the amphipod Gammerus locusta under some of the stones.

Small Fish

Under the landing stage at the south end of the pier I discovered a Greater Pipefish, Syngnathus acus. It was lying perfectly still amongst some rusting pipe and metalwork and could easily have been missed by the unpractised eye.

Other fish present included  a single Butterfish, Pholis gunnellus, a couple of Bullheads (or Sea Scorpions) Taurulus bubalis, and a single Rock Goby, Gobius paganellus.

One dampener from my trip was that a large number of stones had been previously turned over and not replaced. This is an ongoing problem which certainly appears to commence in the spring, often coinciding with the crop of peeler crabs. While most rockpoolers and bait collectors are aware of the damage this causes to the animal communities associated with these rocks and will replace them the way they were found, it only needs a small number of individuals to continually search in this fashion, to damage the short and long term ecology of the area.



1 December 1998
 

December 1st and only 24 days to Christmas. The weather was dry but there was a very cold north-east wind blowing off the land, which made it very chilly underneath the pier head at low water. While the sea was reputedly a number of ° higher than the outside temperatures, hands became very cold once they had been immersed in the water pools.

At first glance the pools appeared quite barren and little was observed. A few Dogwhelks, NucelLapillus,  were braving the elements and feeding on the acorn barnacles high on the pier piles, while at the pile bases more were observed along with groups of eggs. A large green Snakelocks Anemone, Anemonia viridis, caught my eye as it lay partly submerged. Its tentacles were spreadeagled out of the water, it drew a sorry comparison to a handsome expanded compatriot in a deeper pool nearby.

Turning Rocks

There were a few large boulders which promised something and when turned over produced quite a varied menagerie. Large and small porcelain crabs clung to the undersides of the rocks. Three Edible Crabs, Cancer pagurus, lay partly submerged in the exposed sand whilst prawns, Palaemon sp. relocated to other cover in sudden jerky movements, one second and they had moved 50-70 cm.
 

Hairy Crab (Photograph by Andy Horton)Hairy Crab
A single Hairy Crab, Pilumnus hirtellus, scurried off, most probably not amused at having been disturbed. This species of crab has one claw much larger than the other.

Small Fish

Three Long-spined Sea Scorpions (or Long-spined Bullheads), Taurulus bubalis, remained perfectly still, hoping their camouflage would assist in not betraying their location. This was in contrast to half a dozen rocklings. The bronze-brown rocklings were difficult to count, as the shallow rock pool water came alive when the rocks were lifted and rocklings disappeared in all directions.

Sea Anemones

Beadlet Anemones, Actinia equina, were present but not in large numbers and they were easily outnumbered by Snakelocks Anemones. At the most southern point of the pier I found a Dahlia Anemone, Urticina felina, one of the rarer anemones for this site. The disc and tentacles spanned 10 cm in diameter, but it was disappointingly dull in colour, mainly greys and dull reds, with much debris attached to the main column. Further inshore, Snakelock Anemones became more numerous and a few more Beadlet Anemones were found.
 

Sagartia troglodytes
Many of the sandy pools contained the sea anemone Sagartia troglodytes although not in large numbers. Most of those present were in the size range of 20 mm across, including the tentacles.

Crabs

Shore Crabs, Carcinus maenus, were  fewer than in the summer. A few small Hermit Crabs, Pagurus bernhardus, housed in dogwhelk shells lay quietly on the sand surface in the small pools. There may well have been many more if I had looked but by now my hands were freezing cold and it was definitely time to go home.


 

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