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:
Above an illustration of the decline of seaweeds: Juicy whorl weed Chylocladia verticillata all white and fuzzy (see for a more healthy looking plant this post from 2.5 months ago) on a bed of the common and pretty Discoid fork weed Polyides rotundus. There seem to be around 25 or so (larger) species that are common in these pools. Many of them can be seen in the two photos below (including a stray Bladder wrack, a species that dominates the shore just a meter higher): Below, a whole bunch of individual species. First, Sea beech Delesseria sanguinea, which must have washed up from under the kelp beds (too bad I did not get the entire plant in frame…). Second, a photo of Ulva with Chipolata weed Scytosiphon lomentaria. Third, the brown Divided net weed Dictyota dichotoma. Fourth, Slender wart weed Gracilaria gracilis. Fifth, False eyelash weed Calliblepharis jubata; this plant has grown quite large and has turned from dark red/brown to a much lighter brown. Sixth, the Falkenbergia stage of Harpoon weed Asparagopsis armata (see the third photo) on the right. Seventh, Red grape weed Gastroclonium ovatum. Finally, two photos of my favourite species the blue Bushy rainbow wrack Cystoseira tamariscifolia.
Less than 12 hours back in Cornwall and I managed to slide into the rock pools at Castle Beach in Falmouth this Saturday to see what the seaweeds looked like. There was a noticeable difference with only a week ago. The speed at which seaweeds grow, and decline, still amazes me. I managed to take my best photo yet, of Red rags Dilsea carnosa (surrounded by a whole bunch of other species), above. I made so many photos that I will split them over two posts, with some general ‘seaweeds scapes’ here and with individual species in the next post. The Sea lettuce Ulva has been taking over parts of the pools, turning it a bright green. The reds of the Juicy whorl weed and Berry wart cress and pink of Harpoon weed are less bright, and the Red grape weed and Fern weeds are turning ‘fuzzy’. Still, the seaweeds are much bigger and cover most of the seabed and it looks very exuberant. The Wire weed and the Thong weed (or ‘spaghetti weed’) Himanthalia elongata have been rapidly growing; the latter consisted of ‘buttons’ in January and are now a meter long, so must grow around a centimetre a day. The fronds are covered in flakes (which must be reproductive structures) that come off when you swim through them, clouding the water and so ruining the shot if you do not take it straight away. The sun came out more in the last photos, hence the different light (I have edited most (not all) photos slightly using standard Windows Photos, mainly by decreasing the highlights). More photos very soon!
A whole bunch of photos from last Friday, starting out with the prettiest ones depicting a whole range of species, most strikingly the crimson Gracilaria and blue Cystoseira. I was so pleased with it I shared it on the Seaweeds of the NE Atlantic facebook page and Frances Bunker, one of the writers of the highly recommended Seasearch Guide to Seaweeds of Britain and Ireland, kindly uploaded a photo with all scientific names. This is a great idea and I should do the same for future posts (I have not done so yet as I am back home and did not bring the guide). As good as it is to be back in the Low Countries, I am missing out on being able to snorkel in some very good weather and likely better visibility than for the photos in this post. The rock pools have changed markedly since the last post a couple of weeks back, with hardly any patches left without seaweed growth. The colours have changed too, with much more of the green Ulva, and more brown (e.g. Calliblepharis) relative to reds. Some seaweeds seem to be in decline already (e.g. Gastroclonium) while some are more prominent (e.g. Palmaria). Below I have posted a range of photos, some are pretty good, others not so much, but they give a good impression of the diversity (most photos have at least ten species in them but I have not gone through the trouble of typing all the names): I have no clue what the brown, thin, frilly species is above. Below some individual species, first Dulse Palmaria palmata and Sea flax weed Stypocaulon scoparium. Not 100% sure about the next three: Dumontia, Lomentaria and either Laethisia or Colpomenia (I should know this…). Finally, some photos taken under the cover of Thongweed Himanthalia. More photos next week I hope!
More seaweed photos, taken a couple of days after the ones in the previous post, when it was overcast and the water was less clear. The photos are not as good, but there are still a lot of interesting species to see. Below some photos showing the diversity of species next and on top of each other. In the last two months, most species have been growing quite a lot. There are quite large patches of Slender-beaded coral weed Jania rubens. Bushy rainbow wrack Cystoseira tamariscifolia plants are completely overgrown with all kinds of epiphytes, seaweeds, sponges and colonial tunicates, and often have a Nursehound egg case attached. Next, photos of individual species. First some flat reds: Leafy rose weed Rhodophyllis divaricata, Beautiful fan weed Callophyllis laciniata, Branched hidden ribs Cryptopleura ramosa (probably), the invasive species Devil’s tongue weed Grateloupia turuturu and Under tongue weed Hypoglossum hypoglossoides. After that, two species that look a bit similar: left the reddish Discoid fork weed Polyides rotundus and right Clawed fork weed Furcellaria lumbricalis. The former is one of the most common species (also on the photo above it) but difficult to photograph as it usually sits on the white sand. After that, Juicy whorl weed Chylocladia verticillata. Last, two quite unassuming species: Black scour weed Ahnfeltia plicata and Sea flax weed Stypocaulon scoparium. Identifications made possible using the must-have Seasearch Guide to Seaweeds of Britain and Ireland, David Fenwick’s excellent aphotomarine website (and personal communication) and the good people of the Seaweeds of the NE Atlantic facebook group (any mistakes are my own).
Time for some more seaweed photos. These were all taken during a snorkel when the sun was shining and the water was very clear, and as a result they are some of the best I’ve yet managed to take. Often it is overcast this time of year which means that the colours are not vivid and the water can be turbid too, so I was very lucky. Above a ‘bouquet’ consisting of many species, including Chondrus, Dictyota, Corallina, Ulva, Cystoseira, Mesophyllum, Asparagopsis, Calliblepharis, Himanthalia and (probably) Rhodophyllis. I might look slightly ridiculous snorkelling in 50 centimeters of water but as long as I can look at this I don’t care! I really like the clarity of the next photo of Plocamium surrounded by Asparagopsis and Sargassum. The photo after shows the red Berry wart cress Sphaerococcus coronopifolius with some bright green Ulva, kelp and the brown red species False eyelash weed Calliblepharis jubata. More Berry wart cress in the photo after.In the first seaweed post of the year, I posted a photo of a tangle of species, mainly Hairy sand weed Cladostephus spongiosus, with Osmundea, Asparagopsis, Bonnemaisonia and Leathesia (here, third photo). Next, a photo of exactly the same tangle, which is now completely overgrown with the dark red Bonnemaisonia (an invasive species, just as the Sargassum and Asparagopsis also in the photo). I plan to take more photos over the months to track this succession. In the photo after that Bushy berry wrack Cystoseira baccata (still quite spindly after the winter) covered with a couple of red epiphytes and the brown Dictyota dichotoma. The last photo shows a beautiful red species covered in reproductive structures, I hope someone can tell me which species it is! Update: Spotted scarf weed Nitophyllum punctatum.
OK, it was the plan to post a general Falmouth seaweed/rock pool photo post every month but I am faltering the second month in… It is not for lack of trying, because I have been sneaking out of the office quite a bit, but the weather has been pretty awful. Lots of wind, choppy waves, rain, cold and bad viz. I had one good day this week and I am posting some of the better pics from that session. Again a photo of Nursehound mermaid’s purses attached to Bushy rainbow wrack, pretty much the only seaweed species these sharks use to attach their egg cases to. This must be because this seaweed species is very sturdy, and especially because it is a perennial: the eggs can take up to twelve months to hatch! Below three more Bushy rainbow wrack Cystoseira tamariscifolia photos. The first photo shows a short plant with few epiphytes but the following photo shows that this species is an especially great substrate for all kinds of other seaweeds, including Harpoon weed, Fern weeds and Juicy whorl weed. The plant in the third photo (unfortunately out of focus) is completely covered by a beautiful flat red species: Above a general impression of the scene before the sun reappeared. Btw, most of the photo’s have not been post-processed but some I have tweaked a little using the standard photo editor that comes with Windows 10, which is actually really good. The seaweeds have been growing quite a bit since January. A few have become more prominent, such as Slender wart weed Gracilaria gracilis (first two photos) and (I am not 100% sure) Purple claw weed Cystoclonium purpureum in the two photos after that. I have a bunch more photos that show different seaweed species, but I hope that I can take better pictures of these later this month for a follow-up post (I am trying to find a balance between showing what I have seen and posting ‘good’ photo’s, which is a bit tricky!). I have a macro lens now as well, which I will mainly use for animals but also can be used for the smaller seaweeds; the last photo is a first attempt.
The last day of January I took an hour to explore a pool at the upper part of Castle Beach. The resulting shots turned out a lot better than they did the last time. As most of the pools are bare rock, there are no problems with sand/silt, but they are very shallow and on the receiving end of drainage pipes resulting in rain water mixing with the salt water, affecting visibility (this is not necessarily bad as it can make a photo more interesting). It was overcast and I did not experience problems with overexposure; I actually found that tweaking in Photoshop made the photos look worse. Below a Beadlet anemone Actinia equina, the most common anemone on rocky shores. They can be bright red or a drab brown (the green version is rare here) but have bright blue beadlets, or more technically acroraghi. These contain stinging nematocsysts used in territorial fights. After that a small Daisy anemone Cereus pedunculatus, which are usually more mottled in appearance (and not common here, or perhaps I do not know how to look for them…).Next up, a red growth which I should have investigated further, I am not even sure if it is a sponge or something else. After that, a worn Thick top shell Osilinus lineatus, a young Dumont’s tubular weed Dumontia contorta, a red Banded pincer weed Ceramium sp. happily producing oxygen and finally Patella limpets covered in Brown limpet paint Ralfsia verrucosa.
More photography practice lately. I have started to use Photoshop to post-process images, which is hard. I have sat with Thomas Daguerre for a session which was very helpful. For some images, the twiddling is of not much use; the image above of a Bull huss egg case for instance I am pretty happy with as is. Below I have pasted some before and after-Photoshop photo’s. Mostly adjusting highlights and contrast, cropping and playing around with sharpness (in the RAW files), most images tend to be a bit reddish. I have not bothered to tackle the ‘marine snow’ with the Spot Healing brush tool. First, Snakelocks anemones, next, Cocks’ comb Plocamium, then Harpoonweed Asparagopsis armata and an old kelp holdfast covered in feeding Grey topshells Gibbula cineraria. On and under the seaweeds I encounter many interesting tiny animals, but it is hard to take good photo’s without a macrolens. I have pasted a couple photo’s below (none have been edited in any way): the Stalked jellyfish Haliclystus octoradiatus (these can also be reddish or brownish, and can be found on a wide variety of seaweeds), a sponge, a juvenile Snakelocks anemone Anemonia viridis (next to a Flat top shell Gibbula umbilicalis) and the Star ascidian Botryllus schlosseri where I later noticed the fecal pellets underneath. Pooping tunicates, that is what we need more pictures of!Finally, some more before- and after- Photoshop images. The first is the nudibranch Rostanga rubra (‘Red doris’) which was only 5mm or so (see also the tiny Daisy anemone in the background). I shot it today, very cold: 4 degrees, and the water might have been only 8 degrees, brrrr! Next, a closeup of the seaweed Osmundea (see the first photo of this post) which shows its interesting pigmentation. The photo’s are nothing special yet, but I notice I am making progress. Excitingly, I just have ordered a macro wetlens and so hope to get some proper macro photography going soon!
Coralline algae, pink and purple, feathery or encrusting, are a conspicuous part of the local rock pools. When viewed close up, even the crusts are not boring, as they reveal little stalks and holes forming reproductive structures. The above species could be Common pale paint weed Lithophyllum incrustans or Common purple paint weed Phytamoliton purpureum; it is hard to tell species apart and there are likely more species than the few described on websites or in books. In the third photo, the thinner crusts are probably Phymatolithon lenormandii. Only when looking at close-up photos it becomes apparent that juvenile limpets (Patella spp) and White tortoise shell limpets Tectura virginea are very common. Coralline algae are desirable in tropical reef aquariums, as they cover the brownish live rock in pretty colors. There are even special supplements for sale to promote their growth. They need low phosphates and sufficent calcium (as well as magnesium) to grow well, just as hard corals do. Good light helps, although there are also species that thrive under low light. I have a bit of coralline algae in my tank, but only in spots with high flow, so that seems important too. It might be a nice experiment to take a small tank, with a good light source and a decent pump (with rowaphos to keep phosphates down), and add some coralline algae-covered rocks to see what happens. Doing frequent 100% water changes will replenish calcium and magnesium, and not adding animals and food will keep nutrient levels minimal. With some interesting rock formations, it could develop into something pretty.The species Titanoderma pustulatum grows on other seaweeds, such as Irish moss Chondrus crispus on the photo above. Pink plates Mesophyllum lichenoides are coralline algae that are very common on the mid- and lower shore here in Falmouth. They look a bit like a miniature version of Montipora corals. At the moment, some individuals are covered in knobbly reproductive structures housing spores. Pink plates grows epiphytically on Common coral weed Corallina officinalis, the species that makes up the bulk of the coralline algae in the rock pools (see second photo of this post, on the right). Slender-beaded coral weed Jania rubens is also quite common at the moment. Corallina and Jania can be seen growing side by side in the second-last photo. Jania here grows epiphytically on Hairy sand weed Cladostephus spongiosus (this species is normally fuzzy but in winter the branches are bare and slender). I hope to go diving soon and take more photos of the most ‘spectacular’ coralline algae: maerl.