Trevose Head

Was last Wednesday the last sunny day of the year? It might well have been and so it was good I had taken a day off to drive to the north coast for some rock pool snorkeling at Trevose Head near Padstow. A beautiful, empty beach at Booby’s Bay led to the low cliffs of Trevose Head. I did not make it that far up the headland as there were some deep gullies and the waves were pounding below. If you slip and fall on your head you could be in real trouble on these solo outings, so easy does it. Like St. Agnes and Fistral at Newquay the pools were dominated by Brown fork tuning weed Bifurcaria bifurcata, one of my favourite seaweeds and not a species I have ever seen near Falmouth. In contrast to my local Castle Beach spot, the coral weed Corallina officinalis was not bleached but a deep purple and growing much more vigorously. I lowered myself in some of the deeper pools and although the viz was not the greatest I instantly knew the trip was worth it. I tried to get some overall impressions of the pools. What would be really cool is to try to make panorama photos underwater; I might order an underwater tripod for that! There was some green Ulva, a variety of small red seaweeds and Bushy berry wrack (and a little bit of Bushy rainbow wrack) and Sea oak with the same colour as the tuning fork weed. Many limpets were covered in quite a big variety of seaweeds. Not many shots came out well (due to the strong light, overcast days might actually be better) but it would be fun to do a post just on limpets and their mini-ecosystems of epizoic seaweeds. The pools are teeming with Montagu’s blennies Coryphoblennius galerita, I would say more than 10 per square meter. They are very curious and swim up to you, although the little ones then are so skittish that it is still tricky to get a shot. The fish below was a very good model though, quiff up high. Only through this close-up shot I noticed the strange flaps in the corners of it’s mouth. The blueish spots seem striking but also make for excellent camouflage amidst the coralweed.  Beadlet-, Strawberry- and Snakelocks  anemones were common and I also spotted large Dahlia anemones and small Daisy anemones. I saw a large (for the species) Gem anemone Aulactinia verrucosa as well. In the sun, my wide angle wetlens diffracts ligth on the subject which usually is not what you want but resulted in an interesting effect in the second image of the retracting anemone.

Finally, the bright red seasquirt Dendrodoa grossularia which I remember seeing before in Falmouth without realising what it was (the squirts are very small and clumped together). A green stalked jellyfish Haliclystus octoradiatus attached to coral weed unfortunately is not in focus but I like the very striking colour contrast. If only I could get my strobe to work and get good macro shots! This has the best north coast rockpooling site so far and I’d love to go back as soon as the weather (and tide) allows!  

Coralline Algae

img_7483Coralline 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.img_7858 img_7880 img_7558Coralline 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.img_8260img_9131img_8857The 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.img_9531 img_9570img_9307img_9630img_9619