Octopus in Porthkerris

This is the second year of an ‘octopus boom’ here in Cornwall. One of our two native species (Octopus vulgaris) has become much more common, probably due to warming waters. They wreak havoc on the crab pots (it is a big local story), but have made many snorkellers and divers very happy! Although I have spotted them once or twice before, this week I headed down to Porthkerris to have a proper look. Porthkerris is one of the best known shore dive sites in the country, and the only shoredive site in Cornwall I know of that let’s you get a bit deeper than ten meters. Those extra few meters make the difference in spotting things like Cuckoo Wrasse and Sea Fans, and also make it more likely to spot octopus (although these also occur in shallow water; one was even found in a rockpool in Falmouth). Armed with my 8mm fisheye lens I drove down on a Tuesday for two (solo)dives. It wasn’t long before I spotted the first octopus, however it quickly jetted away from me – either they have different personalities or different moods (or both) but not every octopus reacts the same to a passing diver. I managed to get a bunch of shots of several cooperative individuals shown below. Some individuals looked a bit ropey as they were nearing the end of their life-span and I even spotted a dead individual.

I managed shots of some other animals as well, see the gallery below (click on pics for legends). I have done much more macro- than wide-angle photography lately, as it is quite hard in murky English waters. When using strobes it is easy to get backscatter, moving very close to the subject minimises that but makes it hard to get any light between the dome and the subject, often resulting in an unlit centre of the shot and/or blown out spots at the sides. Anyway. I went back on Friday for another two dives. Fewer octopuses (octopi is incorrect!) and worse viz but enjoyable all the same. A selection of critters below. I found a nudibranch new to me (Acanthodoris pilosa) that was so large I could take a halfdecent photo of it using the fisheye lens!

sea gherkin

Another ‘lifer’ yesterday: a Sea gherkin Pawsonia saxicola, at Castle Beach in Falmouth. It is a small sea cucumber (a relative of the Cushion star next to it); a very cool find indeed!

IMG_6745

The main aim though was to collect more snails to help out in the grazing project. This was pretty easy of course. I collected a couple more Painted top shells Calliostoma zizyphinum and many, mainly juvenile, Grey top shells Gibbula umbilicalis. I also picked up a beautiful small Spiny starfish Marthasterias glacialis; this fellow will go after the snails but as long as the predation is not too severe that will be OK, let’s see. Finally, using my little aquarium net, I went after some fish high up the shore and caught a tiny Two-spotted goby Gobiusculus flavescens. I need to catch a bunch more of those, hope to post about that soon