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.

Helford Mudflats

This Sunday we went on a lovely walk from Helford Village to St. Anthony in Meneage on the south coast of the Helford river. The tide was very low, so we decided to follow the mud flats for a bit before heading to the woodlands. The mud flats are a brown-grey and strewn with shells, pebbels and, unfortunately, litter. Not as pretty as the rock pools, but still interesting. There were small banks with mussels, cockels, slipper limpets and oysters, both the native oyster Ostrea edulis (quite some juveniles) as well as the invasive Pacific (or Portuguese) oyster Magallana gigas. Of course also the abundant, barnacle-covered periwinkles Littorina litorea.  I saw my first Auger shell Turritella communis (which does not reflect rarity at all, just the fact that I usually stick to rocky shores); the small shells around it are Needle whelks Bittium reticulatum. Finally a Chinaman’s hat (probably no longer the prefered nomenclature!?) Calyptraea chinensis.We met up with David Fenwick and partner-in-crime Carol who were busy sampling around Treath. David’s interest was caught by a mooring rope covered in seasquirts, and a boxful was collected for careful examination under the microscope later. The clump I am holding below shows the Compass seasquirt Asterocarpa humilis (red, middle) (invasive), Morchellium argus (orange, top) (native), the Dirty seasquirt Ascidiella aspersa (three grey ones) (native) and the Creeping seasquirt Perophora japonica (tiny yellow zoids connected by stolons growing over the Ascidiella) (invasive). Astonishingly, by the next day, in a single tupperware box filled with muddy seasquirts, David had found 70 species! (With 142 species recorded in total on the day.) To finish this post full of grey blobs and brownish molluscs, I am adding photos David made of four out of nine species of Heterobranchs (Nudibranchs ‘proper’ as well as Ophistobranchs) present in the sample. Stunning images and proof that there is tremendous biodiversity to be found on a muddy bank if you know how to look for it. More of David’s nudibranch work is featured in this old post. See for his continously expanding collection of images, from seaweeds to fish and from tiny marine fungi to stranded seaturtles, aphotomarine.com.

Portuguese Man O’ War at Gunwalloe Church Cove and Dollar Cove

The weather today was pretty bad, but it was still very nice to go for a quick stroll on the beach; we chose a new destination: Gunwalloe near Helston. The beach and cliffs here are more reminiscent of some of the North Coast spots, quite barren. At the moment, Facebook and Instagram are overflowing with pretty pictures of washed up Portuguese man o’ wars (or Portuguese men o’ war?) in Cornwall, but we only saw two small shrivelled up ones (at Holywell Beach) so far. It was therefore great to see ten or so on the high tide strand line at Dollar Cove and Gunwalloe Church Cove. The smaller ones measured only five cm or so, with the largest one close to 20 cm (the size refers to the pasty-shaped, gas-filled float or pneumatophore). Unlike true jellyfish, which can move by contracting muscles around their bell, the Portuguese man o’ War (Physalia physalis) just sails. More amazingly, they actually are not individuals but colonies comprised of different, specialized individuals (it is getting late writing this, so I will lazily refer to Wikipedia). Stunning colours and truly great finds!