A quick post on a dive a couple of weeks ago, my first boat dive in Cornwall. Four divers left from Loe Beach in Feock on the Fal Estuary to find the wreck of the Rock Island Bridge at the mouth of the Helford River. On our way we saw a Harbour porpoise which was a first for me, great! The mouth of the Helford is only slightly deeper (nine meters) than it is off Grebe Beach where we usually dive. There is no eelgrass here, just some Divided net weed Dictyota dichotoma and very large Sugar kelp Saccharina latissima lying flat on the bottom. The seabed is an expanse of gravel covered with quite a lot of bivalves: Great scallop Pecten maximus, Rayed artemis Dosinia exoleta, Norway cockle Laevicardium crassum, Dog cockle Glycymeris glycymeris, Common ottershell Lutraria lutraria, Warty venus Venus verrucosa, Pullet carpet shell Tapes corrugata and Hardshell clam Mercenaria mercenaria amongst them. Next time I will collect shells so I can take a good picture of all of them back on land. The place was swarming with starfish feeding on these bivalves, I’d say 90% Common starfish and 10% Spiny starfish. Below a Common starfish Asterias rubens feeding on a clam, a small brittlestar Amphipholis squamata and a Warty venus and Pullet carpet shell.Although the seabed was relatively featureless and we did not manage to find the wreckage, it was fun to watch the Thornback rays Raya clavata (including a large individual with distinctive black headmarkings) and the many Small-spotted catsharks (or dogfish) Scyliorhinus canicula which are very easy to approach. We also saw a Red gurnard Aspitrigla cuculus (see also this old post). However, it is high time we are going to explore some other, deeper dive sites. With the weather deteriorating, I hope we can find some more good days to dive this year though!
A new location for the second dive: Helford Passage between Falmouth and the Lizard Peninsula. This is a shallow, sheltered creek with a sandy bottom and eelgrass beds and can only be dived (well) at high tide. A good site to spot Thornback rays Raja clavata we heard and we were indeed lucky to find several of them. We entered the water at Grebe Beach next to Durgan:
Again, we spotted some cuttlefish, which are not very shy at all. What was very cool were Great scallops Pecten maximus lying around and swimming away for a bit by opening and closing the shell, I will try to film that next time. Many Turban top shells and some large heremit crabs with one or more Parasitic anemones Calliactic parasitica on top. The shells of smaller hermit crabs were covered in the hydroid Hydractinia echinata:
We got to about nine meters depth (near the buoy) and found a large concrete block. Scattered among it lay the remains of crabs and in a hole dug underneath the snout of a Conger eel poked out. As I had to get close for a better look, I stirred up too much sediment and so I do not have a good picture but I will definitely like to go back and have a better look! Interesting was an old crab pot covered in sea squirts (mainly Morchellium) which was swarming with Leach’s spider crabs Inachus phalangium. Normally they sit under a Snakelocks anemone but there were none attached to the pot, strange. Very common were large Peacock Worms Sabella pavonina and Fan worms Myxicola infundibulum: