First proper snorkel session of the year

GyllingvaseThis Thursday was only sunny, but also not windy, with a good low tide in the early afternoon, which meant I reserved a few hours to go to Tunnel/Castle/Gylly beach for some snorkelling. The photo above shows Gylly Beach, with the start of Swanpool lagoon behind it and the Lizard in the far distance. (I took this with my iPhone using a Hipstamatic filter; for more iPhone pics of Cornwall see cornwall_hipsta on instagram…). The water temperature was OK (9C?) but the viz was not as good as I hoped. The seaweeds are at their peak now and the pools looked very pretty. Not many fish, but I saw a small brown thing floating around which I first thought was Sea hare, but turned out to be a small (perhaps a Connemara) clingfish lazing about until it noticed me and bolted into the seaweeds. I carefully snorkelled in about half a meter of water, admiring the views and trying to take photos close-up (as the viz was not too good) with my wide angle wetlens. Below an above-water shot of some iridescent Bushy rainbow wrack Cystoseira tamariscifolia and the invasive red Bonnemaisonia hamifera (on the left). I need to go back studying photography basics. A main challenge is contrast. The pools have beautiful white sand, which result in hugely overexposed photos (or completely darkened subjects). I have come up with my own law, the Photography Frustration Index (PFI): the beauty of the subject (B) x the difficulty of capturing it (D). The PFI is very high in the case of seaweeds! Next: Bushy rainbow wrack under Thong weed, Purple claw weed Cystoclonium purpureum, Bushy berry wrack Cystoseira nodulosum covered with the epiphytes Asparagopsis (left) and Bonnemaisonia (right), Hairy sand weed Cladostephus spongiosus, Black scour weed Ahnfeltia plicata (you can see they grow in the sand and must be used to scouring) a ‘bouquet’ of different species (with a snakelocks anemone) and a last photo of a variety of species, including the common False eyelash weed Calliblepharis jubata. The tides and weather conditions are unfavourable the coming days but I hope to go snorkeling again end of the week!IMG_9393

Falmouth Seaweeds Mid-November

Above the spot where I have been snorkeling all year at Tunnel Beach, between Castle- and Gylly Beach, in Falmouth (Pendennis Castle can be seen in the background). The best time to snorkel is before low tide, as when the tide comes in the viz gets worse. I try to aim for 50-100 cm above the low tide mark which is really shallow. This area is not a real rock pool but rather a gravelly zone between the rock pools proper and the kelp forest which begins past the last row of rocks on the photo. Last week I went snorkelling three times but only last Thursday had decent viz. The photos below show the abundance of pink Harpoon weed Asparagopsis armata, green Sea lettuce Ulva lactuca and new growth of Thong weed Himanthalia elongata and older plants covered in red fuzzy epiphytes. The old wireweed Sargassum muticum plants have died off and the remnants are covered in many epiphytes such as Juicy whorl weed Chylocladia verticilata, Cock’s comb Plocamium cartilagineum and the pretty Iridescent fern weed Osmundea truncata. However, there is new growth everywhere as well so, like Himanthalia, this species seems to have a half-yearly lifecycle. Below some Irish moss Chondrus crispus next to Wireweed. After that, lots of little fuzzy Falkenbergia growing on top of Discoid forkweed Polyides rotundus. This combination grows in a large patch and looks interesting but I struggled to get decent photos, as the dark seaweeds on very white gravel mess up the white balance big time. Next one or two different species of fine flat reds, the last probably Nitophyllum punctatum. The Bushy rainbow wrack Cystoseira tamariscifolia is dying off (here overgrown with Asparagopsis and Dictyota) but the related Bushy berry wrack C. baccata is doing well. Among its epiphytes Spiny straggle weed Gelidium spinosum (ID thanks to Seaweeds of the Atlantic facebook page members) which is also freeliving, and finally the green Codium fragile. One time, when the tide came in, the water was super oxygenated, and all surfaces were covered with small silver bubbles which was beautiful (and annoying as the camera lens was also covered). The following photos show a very different looking Codium fragile, C. tamariscifolia overgrown with Sea beach Delesseria sanguinea and more Thong weed.

Prussia Cove

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:

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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:

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collecting sand

The weather was terrible last weekend so I only went for a brief trip to Flushing beach. It was noticeable that the Dumont’s tubular weed Dumontia contorta, abundant during the last months, is disappearing and flat red and green seaweeds are on the increase:

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I found some Bushy Berry Wrack Cystoseira baccata (I think) and a very fine red seaweed that I could not identify using my Seasearch Guide to Seaweeds of Britain and Ireland:

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An Estuary ragworm Hediste diversicolor:

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My main aim was to get some finer sand to replace the coarse, white gravel collected from Maenporth beach that I have in my aquarium now. This sand is formed for a large part by remnants of Maerl, species of coralline algae. Beds of Maerl nodules are a threatened and important habitat for many animals and also other seaweeds.

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trouble in paradise

A very corny title indeed but wordpress recommended trying to come up with catchy post titles so that’s my excuse… I was very pleased with the way the tank looked after my first serious session of aquascaping. My satisfaction of course did not last for too long. First, I noticed that the water turned cloudy the next day as the result of a bacterial bloom. I quickly changed two buckets of sea water and turned on the skimmer (the Red Sea Max stock skimmer makes an unholy noise and so is usually only on at night (if I don’t forget)). This seemed to help and the water turned clear again within two days or so. I had not expected a bloom to occur, as I added seaweeds (removing nutrients) rather than animals (adding nutrients), plus I had not been feeding frozen artemia for a while. Anyway, this problem has been solved. It is probably better next time to change the tank in multiple steps rather than making wholesale changes. I next noticed the Harpoon weed starting to whither. This has happened before so it was not a real surprise. A close-up of the Harpoon weed when it was still looking good:

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Some Slender-beaded coral weed made it into the aquarium attached to other weeds. As expected, this weed also died and turned white:

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I next noticed that the branchlets of the Red grape weed turned from a dark purple-brown into a fresh green. Although pretty, that this was not a change for the better was obvious when upon touching the plant many of the branchlets were shed. I removed this plant before this debris would clog the filter.

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The main thing that disappointed me though is that the Bushy rainbow wrack steadily lost its iridescent colors and turned into the brown of the other Bushy wrack species. The fact that I had bright blue, green and purple in my aquarium was the most amazing thing about it. Before and after pics:

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I reckon this has to do with the light spectrum not being right. The colors are reminiscent of the Jade vine from the Philippines. Its coloration is the result of two pigments, malvin and saponarin, being present at a specific ratio at a specific alkalinity (wikipedia again). Both Jade vine and Bushy rainbow wrack seem to be fluorescent to my non-expert eye, although a quick search on google did not give me anything on fluorescent plants. Anyway, I will make it my goal in life to find the light conditions that bring back these colors!

To properly experiment with any seaweed it will be desirable to be able to vary the light spectrum and intensity. Probably the best way to go is LED lights, although I am not very knowledgeable about lighting yet and it is all quite complicated (LUX, PAR, micro-Einsteins, Kelvin ratings…) It is also not clear to me if (affordable) LED options are on the market that actually allow you to adjust the light spectrum. I will ask around on some forums. It could also be that the light intensity is not right; I have only used one of the two fluorescent T5 lamps provided with the Red Sea Max 130D as I found the lighting too bright when I started. However, now the tank is full of seaweeds, more of the light will be absorbed and it might not look like I have a tanning bed in the living room. I will pop the other light in and see. The RSM lights are so-called 50/50 lamps that give 50% ‘day light’ and 50% ‘actinic’ (blue) light. Who knows some extra actinic light will help. I need to read up on the subject. There must be other factors as well. For instance room temperature might be too high for some species (this reminds me I need to buy a thermometer!). The Bushy berry wrack, False eyelash weed and Wireweed seem to be doing OK though. Here a picture of Wireweed:

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The tank a week after planting:

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some serious aquascaping

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:IMG_1981

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: IMG_1990

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:

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A goby amidst the False eyelash weed lying on top of what may be Purple claw weed, I am not sure:

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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.

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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.

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I discovered several small whitish Sea lemon nudibranchs Archidoris pseudoargus, very cool.

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