recent rockpool sightings

During my ‘seaweed sessions’ I of course keep my eyes open for animals too. Most prominent are the beautiful Snakelocks anemones Anemonia viridis (see also here). Other anemone species seem much more rare, such as the Dahlia anemone Urticina felina. Little schools of Mysis shrimp are very common (and very hard to photograph) but fish seem less common than a few months back. The common dragonet Callionymus lyra is (as the name suggests) not uncommon but hard to approach, the third photo was the best I could do and demonstrates how masterfully it is camouflaged (but see here what fullblooded males can look like!). Next a very pretty pink sea squirt species and a Broad-clawed porcelain crab Porcellana platycheles, completely flat so, very-well adapted to living under rocks. Finally, a tiny stalked jellyfish Calvadosia campanulata. Stalked jellies seemed to have disappeared over summer, but like the seaweeds are making a little comeback during autumn. There are not many around though, I have seen less than one per hour snorkelling (see this post for better stalked jellyfish photos; I need to work on the depth of field!).

Falmouth Seaweeds Mid-November

Above the spot where I have been snorkeling all year at Tunnel Beach, between Castle- and Gylly Beach, in Falmouth (Pendennis Castle can be seen in the background). The best time to snorkel is before low tide, as when the tide comes in the viz gets worse. I try to aim for 50-100 cm above the low tide mark which is really shallow. This area is not a real rock pool but rather a gravelly zone between the rock pools proper and the kelp forest which begins past the last row of rocks on the photo. Last week I went snorkelling three times but only last Thursday had decent viz. The photos below show the abundance of pink Harpoon weed Asparagopsis armata, green Sea lettuce Ulva lactuca and new growth of Thong weed Himanthalia elongata and older plants covered in red fuzzy epiphytes. The old wireweed Sargassum muticum plants have died off and the remnants are covered in many epiphytes such as Juicy whorl weed Chylocladia verticilata, Cock’s comb Plocamium cartilagineum and the pretty Iridescent fern weed Osmundea truncata. However, there is new growth everywhere as well so, like Himanthalia, this species seems to have a half-yearly lifecycle. Below some Irish moss Chondrus crispus next to Wireweed. After that, lots of little fuzzy Falkenbergia growing on top of Discoid forkweed Polyides rotundus. This combination grows in a large patch and looks interesting but I struggled to get decent photos, as the dark seaweeds on very white gravel mess up the white balance big time. Next one or two different species of fine flat reds, the last probably Nitophyllum punctatum. The Bushy rainbow wrack Cystoseira tamariscifolia is dying off (here overgrown with Asparagopsis and Dictyota) but the related Bushy berry wrack C. baccata is doing well. Among its epiphytes Spiny straggle weed Gelidium spinosum (ID thanks to Seaweeds of the Atlantic facebook page members) which is also freeliving, and finally the green Codium fragile. One time, when the tide came in, the water was super oxygenated, and all surfaces were covered with small silver bubbles which was beautiful (and annoying as the camera lens was also covered). The following photos show a very different looking Codium fragile, C. tamariscifolia overgrown with Sea beach Delesseria sanguinea and more Thong weed.

Practising Fish Photography

This Thursday afternoon was quite bright with low tide still in the ‘OK’ range, however it was quite gusty, resulting in bad viz. As seaweed photography was not an option, I opted to lie down in a midshore rockpool and look at things up close instead. There are a surprising amount of fish in rock pools when you stick your head in and so I chose to have a go photographing them. Most common were Corkwing wrasse, but these are very shy. A pair of Two-spotted gobies Gobiusculus flavenscens hung around a ledge and were easier to photograph. Still tricky though as my standard settings result in limited depth of field; I need to play around with the aperture next time. I will also bring my strobe and videolight to try to bring out the colours more. I tried a split-shot which half-worked but you really need a wide angle dome port for that (not a ‘wet’ wide angle lens). You can see the steps leading from the tunnel entrance to the shore.Two-spotted gobies hover above the substrate instead of lying on it as most other goby species do, but you can see they are very well camouflaged against the corraline algae. Two Tompot blennies Parablennius gattorugine swam up to me. These are the least shy of all the rock pool fish (their cousin the Shanny did not come very close) and easy to photograph as they kept checking me out, striking all kinds of different poses. I need to try to photograph these with my macrolens next time. I turned over a stone and found a Long-spined sea scorpion Taurulus bubalis, these keep very still and are also easy to photograph. Prawns were of course around and are actually really pretty with blue and yellow legs and striped body. Finally a shot of seaweeds in this pool showing fresh growth of many red species and a shot with green Cladophora showing limited visibility due to wave action. Btw, I see this is the 200th post on the blog!

Falmouth Seaweeds October

To my regret I did not manage to take a look at the seaweeds at Castle Beach in September (it was my aim to go in at least once every month). Last Friday however, the sun was shining, the wind was gone and the tide was low (and I was able to escape work) so I at least could make October. Not only was the viz excellent, to my surprise, the seaweeds looked very healthy. It seems that there is a second, autumn seaweed bloom that I was not aware of. Some of the bleached corraline algae have regained their pink colour, the Harpoon weed Asparagopsis armata increased in abundance and I saw species such as Red grape weed Gastroclonium ovatum growing again. The Bushy rainbow wrack has partly died back, forming dense, dark-brown mats (fourth photo) but also show fresh growth. This species is covered in many epiphytes such as Brown fan weed Dictyota dichotoma, and remnants of Bull huss mermaid’s purses still cling on. Interestingly, Wireweed Sargassum muticum has almost completely disappeared. It is tricky photographing rock pool seaweeds. One main issue is to not disturb any sediment, especially as I keep it *very* shallow, sometimes lying on my stomach (I definitely do not need fins). The other main issue with using a (wide angle) wetlens is that there are three glass surfaces in front of the lens collecting bubbles and so need regular wiping. Light is also a challenge: photographing against the sun causes glare, but having the sun in your back results in casting shadows over your subject. I continuously fiddle with the exposure correction, but it remains difficult with the white sand and pebbles around the seaweeds. Below, some healthy looking Solier’s string weed Soliera chordalis, two photos of an ‘unknown’, Norwegian fan weed Gymnogrongus crenulatus, Under-tongue weed Hypoglossum hypoglossoides, seaweeds starting to grow on a pebble, and a rock covered in a variety of seaweeds.

Blue sharks

This Monday I was lucky to be invited to join several colleagues for a trip to find Blue sharks with Chris and Annabelle Lowe of Atlantic Diver. Blue Sharks Prionace glauca are not uncommon around Cornwall at the end of summer but they are a pelagic species and usually do not come close to land. We left at 8:00 from Newquay harbour to go 20 miles offshore, get in a cage and see what would swim up! Chum was made by cutting up mackerel and mushing it in a bucket with a spade, out at sea, it was hung overboard in bags to create a trail. On the way I saw my first ever Sunfish Mola mola; a tiny one (30-40 cm or so) flapping about on the surface. We also saw a variety of seabirds: European storm-petrels, Fulmars, a Great skua and Gannets attracted by the chum. The picture above was taken at the end of the day when the weather was a bit more settled, but it was quite rough when we were on board. Let’s say I added a bit to the chum trail! The Fulmars are supposedly a good indicator of sharks, as they are the firsts to fly off. Not this time though, we spotted a small Blue shark (a bit over a meter in length) but all birds seemed oblivious to it. I had expected for the shark to be a bit closer to the surface, but it remained 5-10 meters deep and was quite hard to see. We took to the cage in pairs. It was bobbing about quite a bit and the water was flakey with mushy mackerel. The shark swam in big circles around the cage, once or twice it touched the cage but otherwise it kept her distance. We believe we saw a second shark of about the same size, but they did not appear together. The slender profile and deep blue colour of the sharks were very striking. One of the sharks had a parasite trailing from the tail fin, probably a copepod. The cage might seem a bit overkill for these sharks (there are two tour operators on the south coast who go out on trips without one), but perhaps not when considerably bigger specimens could also turn up (see this link for a recent angling record) and there are multiple confirmed Blue shark attacks on humans. The swell and ‘mackerel snow’ made it hard to focus, but more frustratingly my camera let me down once again by being unresponsive, so I have to really send it out for repair. I also brought my GoPro (one of the old models without a viewfinder unfortunately).  The longer first clip does not show the shark all the time (GoPro switched its software from ‘Studio’ to ‘Quick’, and whereas it is now easy to add a generic dubstep soundtrack, editing out bits does not seem possible) but gives a good impression of the experience nonetheless. All in all it was a great outing and I hope to go again some time. Many thanks to Chris and Annabelle, a very friendly and knowledgeable couple who are highly recommended for their sea safaris!

 

Falmouth Seaweeds August

Last week when I was chasing whitebait off Castle Beach, I also took some photos of seaweeds. I have been taking photos of seaweeds at this same same spot every month this year (I have made a new tag 2017 Falmouth seaweeds, if you click that, you can easily track the changes back in time). Many species are dying off, so it is definitely not looking as pretty as in March or in April. Below some evidence of the decay: first Furbellows Saccorhiza polyschides covered in grazing Grey topshells Gibbula cineraria and second, discoloured Berry wart cress Sphaerococcus coronopifolius and Red rags Dilsea carnosa Below some species that still look healthy: Bushy rainbow wrack Cystoseira tamariscifolia, Hairy sand weed Cladostephus spongiosus, Chipolataweed Scytosiphon lomentaria (not 100% sure!), Polysiphonia and Codium.

Whitebait 2

After seeing so many Sand smelt (Atherina presbyter) (EDIT or potentially Herring….very difficult to make out position of fins) schools from the local slip and quay in Flushing this week (see previous post), I went for a snorkel on Castle Beach in Falmouth over the weekend. Lots more were to be found! Below two clips. I have hardly shot any videos with my camera, and it unfortunately shows. Shaky camera movement and I forgot I had the option of shooting at a higher frame rate too, doh! I clearly need more practice. Each school consisted of fish of the same size (the smallest fish were around 3 cm and the largest maybe 9 cm), but when chased by a hapless snorkeller some merged temporarily. If you look closely, you can see about one in a hundred fish have a little bite taken out of them, I did not see any predators though.

SandSmelt 5

Falmouth Seaweeds July

Last week I went for a little swim at the usual spot at Castle Beach. The viz was nowhere near as good as last month, but still OK. There are schools of sand eels and sand smelt and I even saw an eel. The contrast between growing brown seaweeds and withering red seaweeds has become even greater. Below you see some yellowed Harpoonweed and a ‘forest’ of Thong weed covered in epiphytes. As the light was a bit subdued, I focused on the most shallow area. The bare parts of the rock are covered with barnacles, dog whelks, sting winkles and limpets. The seaweeds are mainly Serrated wrack Fucus serratus, Sea lettuce Ulva, Grape pip weed Mastocarpus stellatus, some Ceramium and Laver Palmaria palmata, as well as Dumont’s tubular weed Dumontia contorta.

Falmouth Seaweeds (and fish) June

I have been diving three times last week but due to internet problems have not posted about them. I hope to do that in the coming days, but first wanted to blog about this mornings snorkel session in the shallow rock pools at Castle Beach in Falmouth, as I experienced the best viz (visibility) ever here. Apart from the stunning viz, I was very lucky with the fish: I spotted a Tompot blenny, Two-spot Gobies, Fifteen-spined stickleback, Rock goby, Pollack, Ballan-, Corkwing- and Goldsinny Wrasse and Sand eels (above and below). However, I mainly wanted to check what the seaweeds looked like, and things have definitely changed over the last month (see here).The Wireweed Sargassum muticum and Spaghetti (or Thong) weed Himanthalia elongata are thriving and at low tide hang over the surface creating ‘tunnels’. The Harpoonweed below is in decline, turning from pink to yellow-white (and the Bonnemaisonia is almost completely gone). The fronds of the False eyelash weed have turned from juicy and red-brown to wiry and yellow and the corraline algae are turning white. The Sea lettuce Ulva has died back and is covered in speckles (sporangia?). Some epiphytes are thriving, the very fuzzy brown Pylaiella littoralis covers kelp, a Ceramium species grows as pompoms on the Spaghettiweed. One pink and fuzzy species that is growing well I should have taken a closer look at because I am not sure what it is now (I will enquire at the Seaweeds of the NE Atlantic facebook group). The next species I think I can identify: Chipolataweed Scytosiphon lomentaria. The Bushy rainbow wrack Cystoseira tamariscifolia looks fuzzier and greyer than before. Although with less species and more subdued colours, the pools still look beautiful, and I hope the good visibility will last a bit longer!

Falmouth Seaweeds: End of April

A quick snorkel this Tuesday to check out my favourite rock pools at Castle Beach here in Falmouth. The tide was low, the water still and the sun was shining, creating beautiful shimmers of light. The Wireweed, Thong weed, Sea lettuce and also the Bushy rainbow wrack are in full swing, but most of the other species are in decline, with for instance the Harpoon weed and False Eyelash weed bleaching. Still, it is very pretty! The most common fish encountered so far this year have been Two-spot Gobies, with the occasional wrasse or dragonet. Now, loads of juvenile Pollack Pollachius pollachius have appeared (ID thanks to the excellent folk at the Seasearch Cornwall facebook page). The following photos are all variations on the same theme; I could not decide which ones were best so I just posted the whole lot: In the photo above you can make out some Snakelocks anemones on the right; compare with the last two photos of this post from six weeks ago to see how the same scene has changed. The stalked jellyfish seem to have largely disappeared along with the decline of seaweeds. However, you can still spot the odd interesting animal. The photo below is of the small gastropod Mangelia costata. Probably not very rare, but small (<15 mm) and well-hidden and so not that often seen: