The wind has picked up and will ruin any chances of getting good seaweed shots this week. Too bad, but what can you do? A bit of rockpooling I guess. I took my son out to our local beach in Flushing where the rocks gently slope into Penryn River. Although there are no ‘proper’ rockpools, low tide gives access to a mixture of maerl sand and rocks that can be turned over. It is silty and definitely not very pretty, but there is always something to find. It was an especially good weekend for finding fish, seeing Shannies, Tompot blennies, Rock gobies, Gunnels, Worm Pipefish, Shore Rocklings and a tiny Eel, as well as Sea Scorpion eggs. (One Shanny was quite big and proceeded to bite my son’s hand; he was very brave and we slowly put it back.)
Invertebrates were plentiful too. The main mollusc here is the Variegated Scallop Chlamys varia, which is attached underneath every single rock. We found our smallest Great Scallop Pecten maximus as well. We found some Sea lemons Archidoris pseudoargus and lots of Yellow-plumed Sea slugs Berthella plumula (which apparently can secrete sulphuric acid when disturbed…). A small selection of what we found below, all pics taken with an Iphone.
I had the pleasure to go on two dives with Mark Milburn of Atlantic Scuba on the ‘Stingray’ RHIB this weekend and last, leaving from Mylor Harbour (see photo above). The first dive was in the Helford Pool, a deep area in the otherwise shallow Helford river. Buddied up with Sue and Al, we descended to 18 meters to swim over a gravelly area covered with tunicates and sponges. This was a drift dive but we did not get all the way to the eastern end of the pool where some small maerl beds are located. Swimming crabs and Leach’s spider crabs were very common; there were not many fish though. One exception was a cute little John Dory Zeus faber. I was struggling to take any decent photographs, in part because I have not used my strobe much yet and because I should have two, not just one! Sue Barnes kindly let me use a photo she took of the John Dory for the blog; also added is a photo of a sponge, one of the few half-decent ones I managed to take: The dive today took us to the cannon ball site, roughly a mile from Pendennis Castle, and an area where many of the cannon balls fired for practice ended up. With buddy Alex we descended to around 16 m using a shot line. Again a flat ‘rubbly’ area with few fish. The seafloor was covered with Common brittlestars Ophiotrix fragilis. The viz was quite good, and it was much lighter than the previous dive. I also had *a bit* more luck with the strobe. Leach’s spider crabs were common, and we also saw some Sea lemons, Doris pseudoargus, a large seaslug. Up next three common species: a little Rock goby Gobius paganellus, the colonial Antenna hydroid Nemertesia antennina and the colonial sea squirt Aplidium elegans (thanks David Fenwick). I keep my eyes open for seaweeds too of course, there were some small red species and what I suspect is Desmarest’s prickly weed Desmarestia aculeata. I found out back on the boat that I completely missed a small octopus that Alex pointed out, argh! I was very happy though that I managed to spot an Imperial anemone Capnea sanguinea, which is an uncommon species. The photo of this all-white individual was taken without a strobe; I really should have taken more time to get a decent shot. A good reason to go back though, and maybe we can spot some cannon balls then too. The water is 13-14 degrees and so it is still doable to dive with a wetsuit.
I was lucky to go diving twice this weekend, first at Grebe beach next to Durgan in the Helford Passage. As the photo above shows, this is as pretty as Cornwall gets, and the water looked crystal clear at high tide as well. It was a pain to get all picknick stuff and diving gear down (no parking nearby) but it was worth it. Unfortunately I left my fins in my car, so it was a very slow swim out. I emptied my stab jacket and tried walking over the seabed which half-worked (let’s say it was an interesting way of diving). Unfortunately the viz was not as great as expected. I spotted a small squid but it took off before I could take a snap. Other than that no special sightings. Below two images of the eelgrass, two frisky Sea hares Aplysia punctata and a macro photo of a Necklace shell Euspira catena. I had the rented tank refilled at Seaways in Penryn in case there was an opportunity to go out Sunday. The opportunity turned out to be limited to the village where I live, Flushing (opposite the harbour of Falmouth). I had never seen divers in Flushing or heard of anyone diving there, and judging from the siltier conditions and presence of boats that seemed to make sense. However, I always was a bit curious how this bit looked underwater, especially I wanted to check out the extent of the eelgrass emerging at very low tides (see this old rock pooling post). The visibility was not very good and near the shore there was only decaying seaweed. After a while though, lots of eelgras appeared. I was unsure whether this spot is known for eelgrass so I recorded my findings on the seagrass spotter site. This was the first time I brought my new strobe to have a play with, I need lots of practice for sure. Below a Thornback ray Raja clavata photographed with and without flash (no postprocessing used). The eelgrass looked very tall and healthy and many plants were flowering (middle of the photo). Towards the channel the eelgrass thinned out which allowed to observe little mud dwelling creatures. Sea lemons Doris pseudoargusPleurobranchus membranaceus are not that little actually (egg masses present). Finally, a lucky shot. Looking through the eelgrass, a curious school of Seabass Dicentrarchus labrax circled around me quite closeby. (After I left the water I heard a seal was near too but it would have had to be right in front of me for me to see it.) All in all it was a very interesting shallow dive close to home and I will definitely try to return soon.
The day after the very low tide excursion in Falmouth, I had a look in Flushing as well. This site is less pretty, more silty and estuarine, and has a slightly different fauna as well, especially on the muddier areas below the rockpools. (I have written a post about ‘mud pooling’ before.) Lots of sponges, Variegated scallops, European cowries, Hooded prawns and Common squat lobsters. This time I noticed that Hairy crabsPilumnus hirtellus are common here too. Two diffently coloured Long-clawed porcelain crabs Pisidia longicornis:
A pretty sponge Aplysilla rosea (determined using the Aphotomarine page as it was not featured in my otherwise excellent Collins guide):
I had seen one before, but with this low tide I found several Sea lemons Archidorus pseudoargus, large sponge-eating nudibranchs. A large one and a small one together (on the right side of each you can see the ‘naked gills’ which are not extended above water):
Another, bigger individual (European cowries and Thick-lipped dog whelks for scale) again with a smaller individual half under it:
You can see some tiny juvenile Variegated scallops Chlamys varia too. I found my biggest one to date:
They can be much prettier than that though!
I could not resist taking some stuff home to my aquarium, even though I was still waiting for the chiller and new lights (they both have since arrived, that’ll be my next post). There were loads of Painted top shells Calliostoma zizyphinum, which are very pretty and moreover do not often emerge above water so they might be better behaved in the aquarium, and I took some of those home. I also took a pair of Butterfish Pholish gunnellus and some Sea lemons, mainly to observe them for a week or so and then release them again before starting fiddling with the tank. This was not a great succes unfortunately: both Butterfish died within a couple of days. I had acclimatized them to room temperature and I don’t know what the reason could have been. Clingfish, mullet, a rockling, gobies and blennies have never died in my aquarium. I felt really bad about it; definitely no more Butterfish in my tank!
One of the Sea lemons managed to get caught by a Snakelocks anemone….however, it produced copious amounts of slime and it was eventually spat out!
These are my local rock pools at the Trefusis headland near Flushing. On the right is Penryn River (which is not a river at all) with Falmouth on the other bank. Further to the right around Falmouth is the open sea. To the left the Fal Estuary (or Carrick Roads) going all the way to Truro, the capital of Cornwall.