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 pseudoargus Pleurobranchus 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.
After the success of last weeks snorkelling session, it was high time for a proper dive! Again the Helford did not disappoint. In the end, my Sea hare stroking proved a bit inconclusive; also, my estimate of 30 cm long individuals might have been a slight exaggeration, 20-25 cm is more likely for the larger individuals. My guess is that it might be Aplysia punctata after all, and perhaps this is just a very good year where they reach their maximum size. (Note that three individuals can be seen in the first photo and two in the second photo.)This was not the only Ophistobranch activity going on, as I spotted a small nudibranch sitting on the eelgrass. Probably Eubranchus farrani, although it could well be something that is deserving of a new name, there is a lot of (cryptic) species discovery and taxonomic revision ongoing in nudibranch biology. I also spotted several largish egg masses on the eelgrass that are likely to be from a larger, shelled Ophistobranch; I am waiting for suggestions from various facebook groups *could be Haminoea navicula*. I found a beautiful Wooden canoe bubble shell Scaphander lignarius, these animals live buried in the sand so are not commonly spotted. Next time I’ll bring a small garden rake to see what is hidden below the sand (I am serious!), lots of echinoderms and molluscs to be sure. Pelican’s foot shells Aporrhais pespelecani live in sand, but I found some on top of the sand too, so full of muck that they were barely recognizable. I have found empty shells of this species washed up on holidays before, but it was cool to see them alive for the first time.No cuttlefish in sight this time, but loads of eggs so it is likely that this is an important breeding ground for this species. We encountered one Thornback ray Raya clavata, which, like cuttlefish, are not very shy. These species occur in very shallow waters (we probably did not dive deeper than 7 meter) and the influence of the surrounding woodland is clear, with decaying oak leaves and pine cones amidst the seaweeds and eelgrass.One very well-camouflaged species is the Scorpion spider crab Inachus dorsettensis. Medium-sized Common hermit crabs Pagurus bernhardus are common, running around in Turban top shells covered with hydroids. Although present in the last post, another pic of a
Mud sagartia Sagartia troglodytes anemone Red speckled anemone Anthopleuris ballii. Filterfeeding worms are abundant too, including the beautiful Fan worm Myxicola infundibulum as well as a large tube-dwelling worm and worms in white calcareous tubes with bright red bristles that I could not identify. As we got out of the water, we saw a Comb jelly Beroe cucumis, very pretty but hard to photograph. The next dive will have to wait two weeks or so, but then I hope to finally play around with my GoPro.
A nice long snorkel in the Helford ‘River’ from Grebe Beach today. The weather was great and so was the water temperature. The timing was good too, close to low tide, so the Eelgrass beds started at only about one meter depth. There were a lot of cool new finds. What was most striking was the extremely large number of Sea hares Aplysia. There was almost one every other square meter, ranging from 5 to 30 cm, and from grey to light brown to very dark brown. The common species Aplysia punctata ususally reaches 7 cm (occasionally up to 20 cm), so the size and often reticulated veining probably make it A. depilans. From David Fenwicks aphotomarine site: “An easy way to distinguish this species from (a third species) Aplysia fasciata is to run a finger from front to back on the dorsal surface. If the finger cannot travel all along the animal from head to tail then it is A. depilans.” This I did not know so I need to go back and stroke some slugs! I see that these large (up to 40 cm!) beasts have been found here before. A not particularly large individual on my hand, as well as an orgy, with some orangy strings of eggs visible:
Another interesting mollusc to see was the predatory Necklace shell Euspira catena (not a very good shot, would be nice to go back diving soon so there is more time to take pictures). Other nice finds include a Mud sagartia Sagartia troglodytes anemone (I think!) and a small Sagartiogeton undatus anemone. Finally, at only 2 meters depth, we found a good-sized cuttlefish Sepia officinalis, lying still trusting its camouflage. In places, black Sepia eggs could be seen attached to the Eelgrass. Some of us also spotted a juvenile thornback ray in the shallows:
The aquarium was in desperate need of a make-over (again…). I hauled a ton of rocks over from the beach and stacked them up. (I thought at first that I would need something to stick the rocks together (epoxy, superglue or waterfall foam) but that wasn’t really necessary). I also removed most of the gravel and replaced it with sand. So quite a big change but it really looks a lot better. However, my nice burrowing Red-speckled anemones suffered a bit when putting the sand in, and even after siphoning it off again I could not really find them anymore….hopefully they turn up again! The aquarium is still a bit bare and I have to go out and collect things that will live on the rocks, such as anemones and seaweeds. However, there is some progress on the seaweed front. There is a bit of Irish moss Chondrus crispus growing spontaneosly from the back wall. There are also some patches of pink corraline algae; which must be Coral weed Corralina officinalis judging from one outgrowing patch. Having this species grow would be great, but they do not seem like fast growers. Chrysymenia wrighti is still thriving on the circulation pump; I remove a bit every now and then, so it acts as an ‘algae scrubber’, removing nutrients from the water. I have placed a couple of other seaweeds in the aquarium, a bit risky as they can die off and start trouble, but I can’t help it. The red Soliera chordalis below has done well before but unfortunately has started to die off a little already (first pic). I have a big piece of a flat red species that has started to grow from nowhere as well (second pic).One day, the aquarium was full of strings of Painted topshell eggs. I noticed when feeding a day later that the water was not very cold: I had forgotten to switch the pump/chiller back on two days previously! So the trick to breed this species is to increase the temperature, although I am not expecting much to happen with the eggs. Either the Thick-lipped or Netted dogwhelks are also occasionally sticking their egg masses to the glass. I placed a chunk of orange Estuarine sponge in the aquarium; this was devoured by Painted topshells and Cushion stars, so it is a good bit of live food to add. I had planted a little washed-up eelgrass plant to see if it would survive and indeed it has grown more roots. (If you want to try this yourself, please always use washed up plants and don’t dig out any, as eelgrass beds are vulnerable habitats.) It would be great to have a second tank dedicated to eelgrass….The little scallop is still happy (see close-up). I have added another filter feeder: a Leathery sea squirt Styela clavata. Butt-ugly, but that is actually fun too. I am trying it out as they are an invasive species and so probably pretty hardy. A Sting winkle seems to like it (but not eat it). I have never seen my two Sting winkles eat anything actually. They move about very slowly, but they have grown.Now the snakelocks anemones are gone, I have added some more fish. I have caught some juvenile Pollack Pollachius pollachius with my net. At first I caught ones that were less than an inch, but they did not survive. Of the six two-inch or so ones I caught, three dissappeared after one day, but the remaining three are going strong. Very nice looking fish! I also caught a little Tompot blenny Parablennius gattorugine (by hand at low tide). It is quite shy, but is increasingly showing itself. A beautiful little fish! I have one remaining Two-spotted goby. The Common goby is doing very well and eats from my hand. I think I’ll go for another little tompot, more Pollack and Two-spotted gobies. Ideally I would catch some Leopard-spotted gobies with a trap when diving, let’s see….The other fish I would like to have again is the Goldsinny wrasse: very pretty and not as nervous as Corkwing wrasse.
The tide this Sunday in Flushing was as low as it was the day before in Mount’s Bay and the weather was just as great too. We could walk among the Eelgrass and Golden kelp Laminaria ochroleuca. There were lots of Snakelocks anemones Anemonia viridis around; especially striking were patches of what must be clones. The tentacles are much shorter than the ones in my aquarium or those found deeper on kelp, must be due to being less exposed to the waves. Loads of fish as is usual here, a single overturned rock yielded five species alone! Again pictures of the Connemara clingfish Lepadogaster candollei, a Butterfish Pholis gunnellus (very wriggly, hard to get a good shot) and Tompot blenny Parablennius gattorugine eggs:
This site is sheltered and silty and some species are more characteristic for this habitat and much less common in Castle Beach in Falmouth. Examples include the Keyhole limpet Diodora graeca, the Elephant hide sponge Pachymatisma johnstonia and the Yellow-plumed seaslug Berthella plumula:
The diversity of seaweeds was very high and I think the pictures below give a good impression of that. Very low on the shore Bushy noduled wrack Cystoseira nodicaulis can be found; in this case almost as iridescent as is Bushy rainbow wrack Cystoseira tamariscifolia. We found some Beautiful kidney weed Kallymenia reniformis, here David Fenwick is taking a photo of it on his first visit to my local haunt. All in all one of the best rock pooling weekends so far!