Snorkeling in summer is nice because it is sunny and warm, but the seaweeds are turning a bit manky. That has its charms too though!
Above: Furbelows Saccorhiza polyschides. Middle: Thong Weed Himanthalia elongata covered in epiphytes (Ceramium?). Bottom: seaweed assemblage with Red Rags Dilsea carnosa, Irish Moss Chondrus crispus, Forkweed Dictyota dichotoma, Harpoon Weed Asparagopsis armata, Sea Lettuce Ulva lactuca and other species.
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!
As I noticed that the rock pools have started to look really pretty, I have gone out snorkelling four times the last week to photograph seaweeds. Bitterly cold (around 10°C) but worth it! It is my aim to post photo’s taken at the same spot every month this year, let’s see. The first three days the tide was very low, making it more of a lying on the sand rather than actual snorkelling. The sun was out and my main challenge was to get to grips with overexposure, checking histograms and decreasing image brightness. The other main challenge is to not stir the sand up and create ‘marine snow’. It makes a world of difference to actually stick your head underwater and look through the viewfinder instead of lazily only submerging the camera. For now, I have only cropped and adjusted contrast of jpegs using Picasa, but I have also shot in raw format and hope to get more out of the shots in the near future. With help from the excellent Seasearch Guide to Seaweeds of Britain and Ireland and the Seaweeds of the NE Atlantic facebook page some of the species could be identified. Above, Osmundea osmunda (probably), which has a very nice blueish (‘glaucus’) tinge (I need to take some close-ups of that next time). In the following photo, a whole tangle of species, mainly Hairy sand weed Cladostephus spongiosus, with Osmundea, Asparagopsis, Bonnemaisonia and Leathesia. Next, another picture of a whole variety of species, I would like to find out what the red epiphyte is. Below some photos of individual species of red seaweeds (mostly not great but it gives an idea of the diversity). First, Leafy rose weed Rhodophyllis divaricata, next Falkenbergia (which is actually not a species but a distinct phase in the life cycle of Harpoonweed Asparagopsis Armata), Berry wart cress Sphaerococcus coronopifolius, Irish moss Chondrus crispus, Beautiful fan weed Callophyllis laciniata, Under tongue weed Hypoglossum hypoglossoides, Chondrus with Falkenbergia and Hypoglossum and Plocamium on top and a small unknown species. You can see that most photos suffer from overexposure (and notice my crude upped contrasts). The last time I went snorkelling, it was overcast and the tide was higher. I tried a bunch of shots a greater distance away to capture more of an overall impression, but with more water between the subject and the lens the shots become ‘milky’. The next shot of a whole variety of red, green and brown species (with Clawed fork weed Furcellaria lumbricalis in the middle) could have been really nice with clearer water, better framing and correct exposure! The next shot shows Cladostephus and Thong weed Himanthalia elongata on top of a rock covered with Red grape weed Gastroclonium ovatum (also on the last photo).
Last weekend I went down to Gylly Beach in Falmouth for a bit of rock pooling. However, the tide was not very low (especially with the inshore wind) and the weather was crap. Moreover, I could not find anything that I had not seen many times before; although rock pool life is very biodiverse, there have started to be dimishing returns when looking for non-microscopic organisms. Clambering over yet another rock, I decided to stop and play around with my Canon Powershot instead. I focused on a tiny pool (around two by four feet) completely covered in corraline algae. It does not look like much but taking the time for a carefully look was really rewarding. It is tricky to take photographs without being able to see the viewfinder though. My strategy has been to just take loads of pictures and hope some of them work out. The miniature underwater landscape was really beautiful. Pink plates Mesophyllum lichenoides made up the largest proportion of corraline algae (some bearing ‘reproductive conceptacles’). Another species is Corallina officinalis or Common coral weed (third photo). I had some Corallina growing in my aquarium at some point, but it grew very slowly and has now disappeared. Being able to create the right conditions for coralline algae to thrive in a coldwater aquarium would be fantastic, but I have not seen any evidence of anyone being able to cover their aquarium in them yet. (I have tried ‘planting’ Corallina and although it looked very nice at first (fifth pic), these seaweeds quickly died off, turning orange and then white (second pic).)Some other seaweed species were present as well; Irish moss and Harpoonweed (not pictured), False eyelash weed Calliblepharis jubata occurred in multiple patches, Rhodophyllis divaricata?, an Osmundea species and Red grape weed Gastroclonium ovatum. There were also a few brown seaweeds, the characteristic Thong (or Spaghetti) weed Himanthalia elongata buttons and the invasive (and pervasive) Wireweed Sargassum muticum. I did not spot too many animals, although I am sure there is an enormous hidden diversity present among the seaweeds. I noticed a red-white Dahlia anemone Urticina felina as well as some patches of a colonial brown tunicate. I’d like to go back soon and take some more pictures, with my Canon powershot or with my GoPro. I have an SLR as well that I have not been using lately as my iPhone is such a good camera and hassle-free. SLR underwater housings are really expensive, but I recently discovered that there are quite cheap waterproof SLR bags available which might be an option to try to take higher quality photos (in rock pools, I would not go diving or snorkeling with them). It would be very cool to try to make panorama pictures of rock pools, especially when taking one each month in the same spot to capture seasonality. More seaweed photos, Canon powershot or otherwise, to follow soon!
This snorkel session was also the first time I took a proper look underneath the kelp. Mowing through this forest is very interesting. Besides the gobies and starfish, there are a lot of sponges, bryozoans and hydroids to be seen. A picture from this ‘turf’ with many hydrozoans and a larger erect bryozoan (perhaps an Alcyonidium species?); these are groups I know very little about. A photo beneath that of some worms Bispira volutacornis, very beautiful:
The kelp is covered by a not so pretty, large, fluffy brown seaweed which might be Pylaiella littoralis (first picture). Large bushes of the slightly iridescent Dictyota dichotoma were also common, this is a species I have never seen in rock pools (second picture). The rocks underneath the kelp are also home to many red seaweeds, notably Sea Oak (I have to get back for some pictures).
In the deeper channels there were many Mermaid’s tresses Chorda filum, more than five meters in length. The shallow rocks were covered with Thongweed Himanthalia elongata and Grape pip weed Mastocarpus stellatus with assorted epiphytic tufts of fine red seaweeds.
As in Falmouth, the rock pools in Flushing are not looking that great at the moment. Lots of the Corallina has turned white/died (although the clumps in my tank are still their normal purple!). Of course, many species were still thriving, Grape pip weed Mastocarpus stellatus (top), Bunny ears Lomentaria articulata (bottom), new Thong weed Himanthalia elongata ‘buttons’ and a young blade of kelp along with some green Ulva:Among the seaweeds that were thriving was Slimy whip weed Chordaria flagelliformis (I am by no means a seaweed expert and I might be wrong about this, please comment if I am!) and also the beautiful Harpoon weed Asparagospis armata growing as an epiphyte on some darker coloured False eyelash weed. Harpoon weed is invasive and so a good candidate to do well int he aquarium (as most invasive species are quite opportunistic and not too finnicky). It died off in the tank before, but I decided to bring some home to try again now I have a chiller.
Another tangling invasive species: Bonnemaison’s hook weed Bonnemaisonia hamifera (a characteristic curved hook can be seen in the top-middle):Loads more seaweeds to be found but I will save those for another time. All kinds of tunicates pop up in spring, some of them pretty (see for instance here), some of them less so. For instance the invasive species, the Leathery sea squirt Styela clava and an out-of-focus photo of a second, large (>10 cm) species that did not get a lot of response on the NE Atlantic Tunicata FaceBook group. Aplidium nordmanni was offered, see here for a much smaller version of that species. Not a looker either in any case!
I brought my little aquarium net and found many juvenile (<1 cm) fish as well as Mysis shrimp. The fish look like gobies but it is hard to see. They were completely translucent and so you can see what this one just ate. I should take some bits of seaweed home to see what comes crawling and swimming out under a little USB microscope (quite easy to make little videos). It is hard to come up with decent images squatting and squinting on a slippery rock with a salt-encrusted mobile phone!
We went to check out Prussia Cove (named after ‘the king of Prussia’ John Carter who used it as his smuggling base in the 18th century) this weekend for some snorkeling action:
The weather was great but there was quite a lot of wind and so the water was choppy and the visibility really bad. We saw hardly any fish. The seaweeds consisted mainly of the common Thong weed Himanthalia elongata and Bushy berry wrack Cystoseira baccata. There were not many rock pools. The only interesting find there was the pretty Brown tuning fork weed Bifurcaria bifurcata:
Although cold and rainy on the bank holiday Monday, the weekend weather was glorious (and low tide was ‘low’), so it was off to Castle Beach in Falmouth:
To me this looks as good as a coral reef! Loads of Harpoon weed Asparagopsis armata, Thong weed Himanthalia elongata and Oarweed or Tangle Laminaria digitata (there are two similar kelp species, but these remain more erect when above water my guide tells me). Also quite some of my favorite Bushy rainbow wrack Cystoseira tamariscifolia shining blue:
Also iridescent: a tiny (<5 mm) Blue-rayed limpet Helcion pellucidum. Normally found on Laminaria kelp, this one sat under a rock:
Especially on the middle shore, there was quite some change in seaweed composition, with lots of Ulva and similarly bright green, slimey algae in the rock pools. The abundant Shore clingfish Lepadogaster lepadogaster had been laying eggs under rocks everywhere:
You can even see the embryo eyes, I am very happy with my olloclip macrolens (although photography in the bright sun is difficult, especially if you do not want to disturb the animals/eggs too much). There were a couple of quite big Edible crabs Cancer pagurus around. The combination of a trembling crab and a trembling hand resulted in a sub-optimal macro photo of its carapace but it is still a neat pattern:
Strangely (and mostly, annoyingly), the second pump of the aquarium broke down before the weekend and I ordered two new ones. The aquarium has not improved without filtration of course. I will be traveling quite a bit over summer so I will not experiment much with it in the near future.