It had been over two months since I last went snorkeling at my spot in Castle Beach. Although I did go on two boatdives (with no photos to show for), let’s say the work-life balance was tipped in the wrong direction. However I had time for a low-tide snorkel this Saturday and it was great to be back in the water, with a Curlew as my only companion. It was the plan to practise strobe photography but unfortunately I did not manage to get my settings right and I was going nowhere. As this is an activity that is supposed to be fun, I decided to ditch the strobe and stick with natural light. Fish I spotted were Ballan- and Corkwing wrasse, two-spot gobies, tompot blennies, a fifteenspined stickleback, a dragonet and sand eels: It is pretty much the worst time in the year for seaweeds but the pools are still quite pretty. The first three photos give a general impression of the seaweeds, including Thong weed, Harpoon weed and Irish moss. After that: Codium spp, Juicy whorl weed Chylocladia verticillata, a big plant of healthy-looking Hairy sand weed Cladostephus spongiosus, withered Red rags Dilsea carnosa and Dulse Palmaria palmata growing on a kelp stipe. I called it quits after two hours. On my way back I noticed an abundant green algae species I had not seen before. David Fenwick identified it as actually being a cyanobacterium rather than a seaweed: Rivularia bullata, interesting! Hope to do a lot more snorkeling before it gets too cold…
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.
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!
The aquarium is still looking OK. The water is very clear and there are no algae on the glass whatsoever, but the brown algae still spread on the seaweeds, even with frequent skimming and the use of Rowaphos. There is some snail mortality, partly because of the Corkwing (who is not that keen on frozen food). I have added some Dulse Palmaria palmata (front left) and also some Chrysymenia wrightii (right, back), which I had growing in the aquarium succesfully before. This is an invasive species from Japan, first spotted in the Mediterranean three decades ago, spotted more recently in Galicia and now also appearing in the British Isles. (So the ‘back row’ of the tank consists entirely of invasive species, Wireweed, Harpoon weed and C. wrightii). In the Mediterranean it occurs in shallow water whereas in the Atlantic it seems to be a deeper water species (see here). It occasionally washes up in Flushing, see the pictures below of a very large plant I found last week (wellie top left yor scale). I hope to go snorkeling some time soon to try to see how much of it is there.
Last Sunday I ventured to the north coast for a rock pool ramble with Matt Slater of the Cornwall Wildlife Trust (see this great blog) and the local marine conservation group (who also have a nice blog). I actually had never rock pooled at the north coast before (shame on me) and so it was nice to see this exposed habitat, quite different from my main haunts at Castle Beach in Falmouth and Trefusis Point in Flushing:
The rocks were much more bare and the number of animals a lot lower. However, there were quite some seaweeds. I finally saw (the edible) Laver Porphyra spp (probably Black laver Porphyra dioica):
Another edible species, Dulse Palmaria palmata, was incredibly common here:
I won’t add too many seaweed pics in this post, but I liked this shot of Serrated wrack Fucus serratus:
Brown and yellow Flat periwinkles Littorina obtusata (or possibly Littorina mariae, I did not bother to check) where common:
We found a Shore cling fish Lepadogaster lepadogaster and a Five-bearded rockling Ciliata mustela:
I found a couple of pieces of a branched seaweed covered in the bryozoan Electra pilosa:
All in all a good session. I hope to go back soon to take better pictures of the seaweeds!
The tides were good this weekend and so we went out to Gylly (Gyllyngvase) Beach in Falmouth, specifically the rocks to the west of the beach (I normally go to Castle Beach to the east):
Although the tide was quite low, no special sublittoral species were encountered, but everything time you go out you still see something new. For instance, a newly moulted Furrowed crab, Xantho incisus pink and soft next to its old brown carapace:
There were very many small Blue-rayed limpets Helcion pellucidum (see also here) on the kelp:
I am not sure if I like the term aquascaping much because of it’s connotations with gardening and I like a more natural look. However, aquascaping is the general term for arranging plants in an aquarium nowadays and that is what I attempt to do as well with seaweeds. (Also, I cannot pretend that my tank looks particularly like a real rock pool…). Anyway, I will post some more thoughts on the topic of aquascaping, marine or fresh water, later but for now just wanted to show some of the first attempts at planting my aquarium, It is challenging to make any tank look ‘right’, but I found it particularly hard to recreate a rock pool feel. I soon found out that I did not have enough rock in the tank and so hauled some *heavy* ones from a nearby beach. The bare tank:
Another version with Serrated wrack Fucus serratus (left), a small mop of Dudresnay’s whorled weed Dudresnaya vertillicata (far left) and some Solier’s red string weed Soliera chordalis (middle and right). A bit messy:
A worm pipefish, dog whelk and hermit crab in front of the serrated wrack. There is a lot of algal growth and detritus on the wrack. (I have since bought a circulation pump to keep detritus in suspension so it can go into the filter, more about that later).Another go. The nice thing about having an aquarium with native species is that you can collect them yourself, which is half the fun (and free), and when something does not work out you just chuck it back and try something else. The green seaweed is velvet horn Codium tomentosum, the long brown seaweed is wireweed Sargassum muticum. Both did well, the wireweed grew quite fast, perhaps not a surprise as it is an invasive species in the UK. The red seaweed on the left is dulse Palmaria palmata, on the right harpoonweed Asparagopsis armata. The harpoonweed was not exactly thriving and the dulse was quickly eaten by the prawns:Recently, I noticed the Dudresnay’s whorled weed (love that name) sprouting from the rocks everywhere. This happened some months after removing a pluck of this weed from the aquarium. Up till then I had just planted seaweeds, but having them establish spontaneously I had not seen before. Most of the newly established weeds are only a couple of centimeters and do not seem to grow very fast, but the two weeds pictured above grew to 10 centimeters in a couple of weeks. Perhaps very local conditions in the aquarium matter.