Underwater Fluorescence

It has been three months since the last blog post so high time for an update. I have not been out much as the weather has been grim. In fact, the photos in this post are one year old! I bought a blue LED light for fluorescence photography which has been gaining popularity in recent years. Many organisms and fluoresce (i.e. absorb light and emit it at a longer wavelength), although the function of this is generally not well-understood (perhaps in some cases it might not even have a function and just be a byproduct). Coral reefs can especially be spectacularly fluorescent but the cold waters of the UK harbour a variety of fluorescent organisms too, most notably anemones and corals, see here for great marine fluorescence photos from Scotland by James Lynott. Anyway, I bought my light and a yellow barrier filter (which serves to let the emitted fluorescent light through but not the blue light) to be held in front of the camera housing, as well as a headset barrier filter from a very knowledgable German chap here; his site contains a lot useful information for those interested in the background and applications of this type of photography (see also here, here and here). The photography is very tricky: the ISO needs to be bumped up in the dark which results in a lot of noise. The dark also requires long shutterspeeds which results in shaky images. A large aperture for more light is best, but since the subjects are usually small this results in suboptimal depth of field.  I have only been out twice last January, and only whilst rockpooling (I have not done a single nightdive or nightsnorkel in Cornwall and I am not overly tempted to do so!). The very shallow rockpools high up at Castle Beach in Falmouth reveal some fluorescent animals, including hermit crabs but I focused on anemones. Snakelocks are big and very fluorescent (the green ones, the grey variety is not, although it does emit red light via its symbionts) but not common high up the shore. Hardly visible normally due to their small size and inconspicous colours, red-speckled anemones, daisy anemones and gem anemones become apparent using a blue light (in fact, this method is use to study tiny coral recruits in the tropics). The top photo shows two green gem anemones Aulactinia verrucosa (with red and purple coralline algae in the background). The anemones are very small (2 cm max) and I used my CMC-1 wetlens on my Canon G16. The other two photos show Daisy anemones Cereus pedunculatus. I only later noticed the tiny anemone babies (this is a livebearing species). I hope when the rain and wind disappear and the evenings still start early to go out again and post some more photos. Also, I have bought both a new camera and a new aquarium so I have plenty more to post about!

Good Viz

Wednesday had a good low tide, sun and no wind so I headed out for the water during my (long) lunch break. I was not disappointed with the viz, although the wireweed and thong weed shed tissue (conceptacles and/or epiphytic algae?) which immediately cloud the water so you have to ‘swim and shoot’ before the opportunity is gone. At this time of the year, the seaweed biomass is at its greatest, with lots of Harpoonweed, Wireweed, Sea lettuce, Bushy rainbow wrack and Thong weed but the biodiversity is lower, with many other species such as Discoid forkweed, False eyelash weed, Bonnemaisons Hookweed and Red grape weed gone or decaying. Below some general impressions (more photos from around the same time last year here and here): On the two photos above Bushy berry wreck Cystoseira baccata (along with Brown fan weed and Oyster thief). There are many big snakelocks anemones around and quite some fish, mainly shoals of juvenile pollack, Corkwing wrasse and Ballan wrasse, Two-spot gobies and, beyond the pools above the kelp forest, shoals of sand eels and sand smelt. The wind has picked up again so no more snorkelling in the coming days. I’d love to go for a dive again but my strobe malfunctioned and is back with the manufacturer for repair and so I might wait a bit going back into the water….

May snorkelling

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.

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

Practising Fish Photography

This Thursday afternoon was quite bright with low tide still in the ‘OK’ range, however it was quite gusty, resulting in bad viz. As seaweed photography was not an option, I opted to lie down in a midshore rockpool and look at things up close instead. There are a surprising amount of fish in rock pools when you stick your head in and so I chose to have a go photographing them. Most common were Corkwing wrasse, but these are very shy. A pair of Two-spotted gobies Gobiusculus flavenscens hung around a ledge and were easier to photograph. Still tricky though as my standard settings result in limited depth of field; I need to play around with the aperture next time. I will also bring my strobe and videolight to try to bring out the colours more. I tried a split-shot which half-worked but you really need a wide angle dome port for that (not a ‘wet’ wide angle lens). You can see the steps leading from the tunnel entrance to the shore.Two-spotted gobies hover above the substrate instead of lying on it as most other goby species do, but you can see they are very well camouflaged against the corraline algae. Two Tompot blennies Parablennius gattorugine swam up to me. These are the least shy of all the rock pool fish (their cousin the Shanny did not come very close) and easy to photograph as they kept checking me out, striking all kinds of different poses. I need to try to photograph these with my macrolens next time. I turned over a stone and found a Long-spined sea scorpion Taurulus bubalis, these keep very still and are also easy to photograph. Prawns were of course around and are actually really pretty with blue and yellow legs and striped body. Finally a shot of seaweeds in this pool showing fresh growth of many red species and a shot with green Cladophora showing limited visibility due to wave action. Btw, I see this is the 200th post on the blog!

Falmouth Seaweeds August

Last week when I was chasing whitebait off Castle Beach, I also took some photos of seaweeds. I have been taking photos of seaweeds at this same same spot every month this year (I have made a new tag 2017 Falmouth seaweeds, if you click that, you can easily track the changes back in time). Many species are dying off, so it is definitely not looking as pretty as in March or in April. Below some evidence of the decay: first Furbellows Saccorhiza polyschides covered in grazing Grey topshells Gibbula cineraria and second, discoloured Berry wart cress Sphaerococcus coronopifolius and Red rags Dilsea carnosa Below some species that still look healthy: Bushy rainbow wrack Cystoseira tamariscifolia, Hairy sand weed Cladostephus spongiosus, Chipolataweed Scytosiphon lomentaria (not 100% sure!), Polysiphonia and Codium.

Whitebait 2

After seeing so many Sand smelt (Atherina presbyter) (EDIT or potentially Herring….very difficult to make out position of fins) schools from the local slip and quay in Flushing this week (see previous post), I went for a snorkel on Castle Beach in Falmouth over the weekend. Lots more were to be found! Below two clips. I have hardly shot any videos with my camera, and it unfortunately shows. Shaky camera movement and I forgot I had the option of shooting at a higher frame rate too, doh! I clearly need more practice. Each school consisted of fish of the same size (the smallest fish were around 3 cm and the largest maybe 9 cm), but when chased by a hapless snorkeller some merged temporarily. If you look closely, you can see about one in a hundred fish have a little bite taken out of them, I did not see any predators though.

SandSmelt 5

Falmouth Seaweeds (and fish) June

I have been diving three times last week but due to internet problems have not posted about them. I hope to do that in the coming days, but first wanted to blog about this mornings snorkel session in the shallow rock pools at Castle Beach in Falmouth, as I experienced the best viz (visibility) ever here. Apart from the stunning viz, I was very lucky with the fish: I spotted a Tompot blenny, Two-spot Gobies, Fifteen-spined stickleback, Rock goby, Pollack, Ballan-, Corkwing- and Goldsinny Wrasse and Sand eels (above and below). However, I mainly wanted to check what the seaweeds looked like, and things have definitely changed over the last month (see here).The Wireweed Sargassum muticum and Spaghetti (or Thong) weed Himanthalia elongata are thriving and at low tide hang over the surface creating ‘tunnels’. The Harpoonweed below is in decline, turning from pink to yellow-white (and the Bonnemaisonia is almost completely gone). The fronds of the False eyelash weed have turned from juicy and red-brown to wiry and yellow and the corraline algae are turning white. The Sea lettuce Ulva has died back and is covered in speckles (sporangia?). Some epiphytes are thriving, the very fuzzy brown Pylaiella littoralis covers kelp, a Ceramium species grows as pompoms on the Spaghettiweed. One pink and fuzzy species that is growing well I should have taken a closer look at because I am not sure what it is now (I will enquire at the Seaweeds of the NE Atlantic facebook group). The next species I think I can identify: Chipolataweed Scytosiphon lomentaria. The Bushy rainbow wrack Cystoseira tamariscifolia looks fuzzier and greyer than before. Although with less species and more subdued colours, the pools still look beautiful, and I hope the good visibility will last a bit longer!

Falmouth Seaweeds: End of April

A quick snorkel this Tuesday to check out my favourite rock pools at Castle Beach here in Falmouth. The tide was low, the water still and the sun was shining, creating beautiful shimmers of light. The Wireweed, Thong weed, Sea lettuce and also the Bushy rainbow wrack are in full swing, but most of the other species are in decline, with for instance the Harpoon weed and False Eyelash weed bleaching. Still, it is very pretty! The most common fish encountered so far this year have been Two-spot Gobies, with the occasional wrasse or dragonet. Now, loads of juvenile Pollack Pollachius pollachius have appeared (ID thanks to the excellent folk at the Seasearch Cornwall facebook page). The following photos are all variations on the same theme; I could not decide which ones were best so I just posted the whole lot: In the photo above you can make out some Snakelocks anemones on the right; compare with the last two photos of this post from six weeks ago to see how the same scene has changed. The stalked jellyfish seem to have largely disappeared along with the decline of seaweeds. However, you can still spot the odd interesting animal. The photo below is of the small gastropod Mangelia costata Haedropleura septangularis. Probably not very rare, but small (<15 mm) and well-hidden and so not that often seen:

Upper Shore Pool

img_9490-copyThe last day of January I took an hour to explore a pool at the upper part of Castle Beach. The resulting shots turned out a lot better than they did the last time. As most of the pools are bare rock, there are no problems with sand/silt, but they are very shallow and on the receiving end of drainage pipes resulting in rain water mixing with the salt water, affecting visibility (this is not necessarily bad as it can make a photo more interesting). It was overcast and I did not experience problems with overexposure; I actually found that tweaking in Photoshop made the photos look worse. Below a Beadlet anemone Actinia equina, the most common anemone on rocky shores. They can be bright red or a drab brown (the green version is rare here) but have bright blue beadlets, or more technically acroraghi. These contain stinging nematocsysts used in territorial fights. After that a small Daisy anemone Cereus pedunculatus, which are usually more mottled in appearance (and not common here, or perhaps I do not know how to look for them…).img_9502img_9483Next up, a red growth which I should have investigated further, I am not even sure if it is a sponge or something else. After that, a worn Thick top shell Osilinus lineatus,  a young Dumont’s tubular weed Dumontia contorta, a red Banded pincer weed Ceramium sp. happily producing oxygen and finally Patella limpets covered in Brown limpet paint Ralfsia verrucosa.img_9527img_9583img_9568img_9597img_9522img_9492