A quick post to keep the blog going. Seaweed season has passed me by a bit, first because of the bad weather and second, when the weather was better, because I did not have much time to go out. I went snorkelling only twice in May in my usual (shallow) spot at Castle Beach in Falmouth. On the 13th of May the plankton bloom was in full swing: a (wannabe) photographers nightmare! Generally, the seaweeds at this point were already a bit ‘over the hill’. I managed to get a nice shot of Berry wart Cress Sphaerococcus coronopifolius though (above). I also glimpsed what I believe is Iridescent Drachiella Drachiella spectabilis under a rock overhang. The bright blue Bushy rainbow wrack Cystoseira tamariscifolia contrasted very nciely with the deep red of the Red rags Dilsea carnosa, I hope to get a much better picture of that (probably next year…).By the next snorkel session the 19th, the visibility was much better. Some photos of the green seaweed Codium sp., A Gelidium sp. (pulchellum?) and a patch of Slender-beaded coral weed Jania rubens growing epiphytically on Hairy sponge weed Cladostephus spongiosus with the very common species Ulva and Oyster thief Colpomenia peregrina (and others). Next, Beautiful Fan weed Callophyllis laciniata and another Berry wart Cress Sphaerococcus coronopifolius. Finally, three shots giving a general impression of the seaweed growth and what I think is Chipolata weed Scytosiphon lomentaria as well as a snakelocks anemone inbetween yellowed False eyelash weed Calliblepharis jubata. About the animals: there are some juvenile pollack around, as well as two-spot gobies. I saw a brown, flabby shape drifting through the water at one point and my first thought was that it was a seahare but it actually turned out to be a small clingfish (I could not get a photo unfortunately). There were quite some polychaete worms erratically swimming around in their reproductive ‘epitoke’ stage. The final photo shows one (with a Nassarius reticulatus in the background) which could be Perinereis cultifera.
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).
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.
With the seaweeds collected, it was time to plant my aquarium. This time I took a more serious approach, I planted lots. Many of the seaweeds had bits of rock attached to their holdfasts which made it easy to anchor them in the gravel. Two of the weeds I tied to rocks with a piece of elastic band, easy peasy:
View from the left side. False eyelash weed Calliblepharis jubata in the front, tall Wireweed Sargassum muticum and in the middle some coarse brown sea weed which almost looks like a dead conifer. This is probably Bushy berry wrack Cystoseira baccata:
An expanded view, on the right some Red grape weed Gastroclonium ovatum, in the middle the red pluck of Dudresnays whorled weed Dudresnaya vertillicata that I already had:
A goby amidst the False eyelash weed lying on top of what may be Purple claw weed, I am not sure:
The magnificently coloured Bushy rainbow wrack Cystoseira tamariscifolia covered in green Snakelocks anemones Anemonia viridis. In the foreground the pink Slender-beaded coral weed Jania rubens and Harpoon weed Asparagopsis armata.
A close-up of the Bushy rainbow wrack. Other plants were bright green or purple. I never knew that seaweeds existed with these iridescent colours. In fact, when I glimpsed one for the first time in a rock pool I disregarded it because I thought it was some seaweed covered in oil slick! These weeds are also have a very cartilaginous texture which give them more of an animal-like appearance.
I discovered several small whitish Sea lemon nudibranchs Archidoris pseudoargus, very cool.
Hello! For the last half year or so, I have been messing with a marine aquarium housing sea weeds and critters collected from local rock pools here in Cornwall. I thought it would be fun to blog about my aquarium project, especially after I discovered that it is quite easy to take nice aquarium pictures using an iPhone (which I found nearly impossible using a standard digital camera). After doing some internet research, I settled on a Red Sea Max 130D ‘plug-and-play’ aquarium (I will post about the actual tank later). I could not find much information on the web on temperate marine tanks, especially ones without a chiller or a sump. and few of those seem to focus on seaweeds. So who knows I may have found a niche. Below I have posted some pictures from when I was setting it up last year:
Half a bucket of gravel collected from a nearby beach, RO water taken home from the lab where I work (carried back 2×10 L at the time, the tank is 130 L) mixed with a free bucket of sea salt that came with the tank. Few sea weeds and not too many rocks. I have since replaced the rocks with bigger ones; most critters are benthic and you do not want to have too much ‘open water’ around with nothing in it. Although too bare, I do like the purple look of this set-up, which has since disappeared because of inevitable algae taking over from the purple crustose seaweeds.
A shanny Lipophrys pholis, this is a very common fish around here that can easily be picked up when turning stones at low tide. The branched seaweed on the left is Solier’s red string weed Solieria chordalis; in the back on the right there is a little pluck of Berry wart cress Sphaerococcus coronopifolius.
A snakelocks anemone Anemonia viridis. Behind it some Slender-beaded coral weed Jania rubens. This weed died off quite quickly; first it turned a bright orange, then white.
The Star ascidian Botryllus schlosseri, a colony-forming tunicate. It did not survive for too long, but that might just have been because the particular broad-leaved red seaweed they grew on are very popular with prawns and hermit crabs. What animals and sea weeds do well has been trial and error. I might compile a list of ‘easy’ species and ones to avoid at some point.