Inachus

This seems like a familiar way to start a blog post but here I go again: ‘the weather has been terrible lately and I have not been in the water!’. March used to be my favourite time for snorkeling because the seaweeds look at their best, but the last three years it has been windy and wet, surely because of climate change…

To keep the blog going (a bit), I have dug out some images from a few dives last year featuring Inachus spider crabs. There are three species, I. phalangium, I. dorsettensis and I. leptochirus, which can be told apart by the arrangement of tubercules on their carapace, but these are often obscured by epiphyte growth, and so I am keeping it to Inachus sp. All species are associated with Snakelocks Anemone (Anemonia viridis) hosts. The photo above is taken using a weird ‘wide angle macro’ wetlens (INON UFL-M150 ZM80). This perspective always fascinated me but it is difficult to achieve. This lens does the job, although it is incredibly ‘soft’, especially around the edges. The close focusing also makes it difficult to direct the strobe light on the subject. So there is a tradeoff between getting the surroundings in view and sharpness. Below first some sharper shots using my 60mm macrolens, followed by some macro wide angle shots (they happen to be each of the different Anemonia colour morph):

I will leave you with the following interesting bit on the biology of these crabs by Diesel (Ethology, 1986):

I. phalangium females are site-constant, and live in the protection of one anemone or group. Males travel frequently between anemones harbouring females due to spawn; they copulate and guard the females until spawning, after which the male leaves again. A male operates in a patrol area containing 3-8 anemone groups and up to 8 females, visiting each female in turn repeatedly just before it is due to spawn. Patrol areas of different males may overlap, with resulting competition to fertilize a female’s next brood. Large males have higher reproductive success than small ones. Females live up to 8 months after the moult of puberty and hatch up to six broods, and males live up to 7 months as adults. A male could fertilize a calculated 26,000 eggs, whilst a female’s reproductive potential is ca. 4,200 eggs. Mortality risks are higher for males than for females, probably because of increased predation while leaving the protection of anemones in order to visit females. Males learn the positions of anemones harbouring females in their patrol areas, and when these are due to spawn. This allows a male to travel with a target and arrive punctually to fertilize the next brood due in his circuit. I. phalangium is the first marine invertebrate reported to use a “schedule” of localities and times for visiting prespawning females. In this way males minimize searching time and mortality risk, and maximize the number of broods fertilized.

Back to Silver Steps

I recently bought (2ndhand) scuba gear and did a refresher dive; with the nice weather this week it was high time to get back under the waves and take some photos! I dived Thu/Fri/Sat at the main local shoredive site ‘Silver Steps‘. I went in by myself, but with a maximum depth of around 10 meters and good conditions this is not risky. The dives did not disappoint, the viz was excellent! Although I spotted cuttlefish every dive, I still opted for the macro lens, as I suspected I could not get great shots of them with my fisheye lens at 1.5 meter distance (I might have been wrong!). Instead of heading out to sea as some divers do, I always stick to the gullies by the rocks, diving below the kelp to see what happens beneath the rocky overhangs. There are three usual suspects hiding there, each with a very different personality. First, Leopard Spotted Gobies (Thorogobius ephippiatus) inhabit cracks in the rocks and are quite shy:

Second, Tompot Blennies (Parablennius gattorugine) are extremely inquisitive, often coming very close to check out what is going on in front of their domain:

Third, Black-face Blennies (which are not true blennies but triple fins) that only ever live under overhangs, usually head-down. I did not see males in breeding colours (black face, yellow body) but this colour form is even prettier I think:

When inspecting the rock walls carpeted in sponges, seasquirts, algae, worms and other things, I kept my eyes out for nudibranchs. Apart from a tiny crested aeolis, I spotted a good number of Discodoris rosi, busy mating and laying eggs. This species has only been observed in the UK for a decade or so but the population now is booming, with many reports coming in from all over Cornwall:

All in all a great enjoyable three dives! Silvery schools of sandeels and sprat/herring, many wrasse, cuttlefish, small and very big lobsters and a greater pipefish were also spotted. Unfortunately the weather has made a turn for the worse this week, however, there are still a few diveable months left this year…

Silver Steps Diving V

Yet another solo dive (I know, I know, not ideal) this Thursday morning before the easterlies are kicking in. Actually, the water was already choppier than I expected, but for macro photography the viz is not as important. I did not get ‘the’ shot but it was a nice dive all around. I discovered a little swim-under and saw lobster, rock lobster (craw fish) and a huuuuge conger eel. I was focusing on a little tunicate when I looked up and saw it looking back at me from not very far away at all. Its head was as big as mine. I slowly swam backwards, thinking of this encounter…..overall they do seem to be aggressive towards people though, and with my fisheye lens this could have been a really good shot. This later happened again, this time a smaller individual but still sizable. I did not stick my macro lens up its nose but grabbed a halfhearted shot with a passing by Twospot goby almost in focus to give an idea: Some macro shots: again a Twin fan worm Bispira volutacornis and a new one for me, a big bright red Protula tubularia. It would be nice to get some abstract close-ups but these are excellent living motion-detectors so it is difficult. There are some amazing colours under the rock overhangs and I would like to try some more abstract photos such as this Spiny starfish or this Didemnun colonial seasquirt and other encrusting animals (and plants). No diving/snorkelling this weekend because of the wind, but glad I could put a couple of dives in these past weeks, and I will make an effort to go a lot more weather permitting!

Silver Steps Diving IV

A solo dive early evening at the Silver Steps site. It was a couple of weeks I last went, and this time it was already dusk when I entered the water. My intention was to find cup corals and other small creatures growing on rock overhangs below the kelp line. The viz was good and sure enough I found what I was looking for: Devonshire cup coral Caryophyllia smithii, a solitary stony coral which is relatively common. They are very beautiful and the right size for the macro lens. I will definitely go after them again. Other finds were a golfball sponge Tethya aurantium, a baby Longspined seascorpion (this shot had potential, but it swam away unfortunately), a tunicate and a Painted topshell (very common). At the end of the dive unfortunately it was getting too dark to find objects or too properly focus; I need to sort out a dive light!

Silver Steps Diving III

I will keep this post short, as my third Silver Steps shoredive of the year was a week ago. As you can see above, my dive was made by encountering the beautiful nudibranch Antiopella cristata (although I prefer the old name Janolus cristatus…). My camera battery strangely gave up straight after taking these pics (argh!), otherwise I would have bothered it for at least another ten minutes! The 60mm lens is great. Look at the European cowrie Trivia monacha below which is less than a centimeter in length. Not a great shot but it shows that it is possible. Finally, a common Phoronid worm Phoronis hippocrepia (Thanks Allison, please check out her great blog Notes from a California naturalist). I hope the wind will die down and I can go back soon.

Silver Steps diving II

Another Silver Steps shore dive with @shannonmoranphoto and her fellow student Chris on Friday. The conditions were not as good as last time: low viz and a bit of a swell. I had set my camera to a longer focal range to try to take pics of cuttles or larger fish but that did not work out (with better conditions it still might not work out!). I could still shoot macro so that is what I did. Above to Devonshire cup corals Caryophyllia smithii. Pretty decent, but I know I can get a better close-up; I will try again Monday! I will have another go at the one resident Cray (or Craw) fish, which lives very shallow. I will also try the Twin fan worm Bispira volutacornis again, as I think a shot filled with just the fans (and not assorted bits of seaweeds etc) could be really nice. I might try free-swimming fish if they come close, as did this Poor cod Trisopterus minutus. Below some before- and after postprocessing. Just the jpegs in Windows Photos, nothing fancy. A bit of cropping, increasing clarity and contrast works wonders. Only when I have a really good photo I will invest time processing raw files in Photoshop. First the best photo of the dive: a Black-faced blenny Tripterygion delaisi (a female or possibly a non-breeding male). Next, a common Edible crab Cancer pagurus and finally a Twospotted goby Gobiusculus flavescens.

Silver Steps Diving

Finally a shore dive yesterday evening, it has been a long time. I partnered up with buddy Shannon via instagram (@shannonmoranphoto). Instagram has been a really nice way to learn about photography from likeminded folks (such as @danboltphoto and @malcolmnnimmo). We dived (dove?) Silver Steps in Falmouth, about which you can find a bunch of old snorkelling and diving posts on the blog if you are interested. Shannon was the ideal buddy: relaxed and really into photography, so we kept the same tempo. It was a very shallow dive (maybe 5 meters), so we were only limited by getting cold, which was after an hour. I chose to use my 60mm lens, but not to use the 1:1 macro setting, but the 0.19-040 focal range to try my hand at slightly larger objects such as fish. I was thus lucky in a sense that I did not encounter any beautiful nudibranchs of which I would not be able to to take a good shot. (Edit: actually, I since learned that 1:1 is still possible using this focal range). It was however unfortunate that I could not get a good shot of a cuttlefish that hovered about two meters away, rapidly changing colour and catching a wrasse! Next time I will perhaps change settings again to try my hand at (cuttle)fish swimming a bit further away. However, I was very happy with sticking to Leopard-spotted gobies Thorogobius ephippiatus. They do not stick their little faces out of nooks as do most blennies, but usually lie on and under ledges. The trick was to approach very slowly, shooting until they swam off. For some reason, I managed to position my strobe right and did not have backscatter issues. I used Windows Photos to postprocess. See below for a before and after example: Two other common organisms below: a Squat lobster Galathea rugosa and a Twin fan worm Bispira volutacornis. And finally an out of focus, but fun photo of a tiny tiny clingfish very aptly clinging to Shannon’s housing. This was one of the most fun dives in ages and I hope to repeat it sometime soon!

First dive of 2018: the N.G. Petersen Wreck

It was time this Saturday: my first dive of 2018! Leaving with Atlantic Scuba‘s Stingray rhib from Mylor Harbour, we plunged in the cold (9°C) water above what remains of the N.G. Petersen in Falmouth Bay. Frustratingly, the indicator light of my strobe kept flashing red and green, so taking decent photos was out of the question. Luckily, I am able to post a nice little clip of this dive made by fellow diver Glyn Kirby (thanks Glyn!). It gives a good impression of life on the wreck and the plankton bloom, reducing the viz quite abit. Inbetween the rubble, some urchins, edible crabs, spider crabs and lobsters. Also great to see five or so (small) Rock Lobsters and some wrasse and shoals of Bib (with some other gadids hanging about too). We saw a small freeswimming Conger Eel and a very big one sticking its head out of a tube (photographic evidence below the video, such a shame the flash did not work because the angle I got was nice). All in all a good dive together with excellent buddy Al. More diving soon I hope!

Pink Sea Fans at the SS Volnay wreck

Today I went for my final dive this year, again with Atlantic Scuba, and this time to the wreck of the SS Volnay (see here and here for background). Just off Porthallow on the Lizard peninsula, at around 17 meters (at low tide) lie the remains of this WWI casualty, hit by a mine and dynamited twice after (probably to get rid of unexploded shells), so she is mostly flattened. The boilers still are largely intact and are very impressive though, see the first not very-well composed shot (should have used my buddy for scale); note the white Dead man’s fingers. This dive would guarantee two ‘lifers’ for me, first the European spiny lobster (or Crayfish or Rock lobster) Palinurus elephas, which seems to be getting more common the last few years. Indeed, we did not have to look hard and saw the long antennae sticking out of nooks and crannies everywhere (see also the Devonshire cupcorals on the second photo). Second, and the main thing I was looking forward too, were the Pink sea fans Eunicella verrucosa. I had found some pieces of this gorgonian washed up on the beach before but never seen it alive. Luckily, at this site it is a common species (many juveniles, unbranched little ‘sticks were also present). I took a whole bunch of snaps and edited the jpgs in the standard Windows photo viewer (I keep the RAW files but need to find some time for proper post-processing). Just reducing highlights etc does wonders, but what I really need to do is be more clever with my camera settings in the first place. My New Year’s resolution will be too think ISO and aperture and not lazily rely on presets. I might also invest in a strobe capable of manual control (thanks for tips kelpdiver @dpreview!) High time to up my game! Below, three of the sea fan photos that came out best. Lastly, a nice new species for me: Trumpet anemones Aiptasia mutabilis. My four recent dives with Atlantic Scuba have all been great; a boat full of friendly divers leaving from just down the road in Mylor, skippered by Mark Milburn who has a very deep knowledge of the area. Todays dive with buddy Jan was very relaxed but I still learned a thing or two. More diving next year! P.S. Mark Milburn just published “Falmouth Underwater: a Guide to Marine Life, Wrecks and Dive Sites around Falmouth” (available here) which I highly recommend to anyone planning to dive or snorkel in the area!

Two November Boat Dives

I had the pleasure to go on two dives with Mark Milburn of Atlantic Scuba on the ‘Stingray’ RHIB this weekend and last, leaving from Mylor Harbour (see photo above). The first dive was in the Helford Pool, a deep area in the otherwise shallow Helford river. Buddied up with Sue and Al, we descended to 18 meters to swim over a gravelly area covered with tunicates and sponges. This was a drift dive but we did not get all the way to the eastern end of the pool where some small maerl beds are located. Swimming crabs and Leach’s spider crabs were very common; there were not many fish though. One exception was a cute little John Dory Zeus faber. I was struggling to take any decent photographs, in part because I have not used my strobe much yet and because I should have two, not just one! Sue Barnes kindly let me use a photo she took of the John Dory for the blog; also added is a photo of a sponge, one of the few half-decent ones I managed to take: The dive today took us to the cannon ball site, roughly a mile from Pendennis Castle, and an area where many of the cannon balls fired for practice ended up. With buddy Alex we descended to around 16 m using a shot line. Again a flat ‘rubbly’ area with few fish. The seafloor was covered with Common brittlestars Ophiotrix fragilis. The viz was quite good, and it was much lighter than the previous dive. I also had *a bit* more luck with the strobe. Leach’s spider crabs were common, and we also saw some Sea lemons, Doris pseudoargus, a large seaslug. Up next three common species: a little Rock goby Gobius paganellus, the colonial Antenna hydroid Nemertesia antennina and the colonial sea squirt Aplidium elegans (thanks David Fenwick). I keep my eyes open for seaweeds too of course, there were some small red species and what I suspect is Desmarest’s prickly weed Desmarestia aculeata. I found out back on the boat that I completely missed a small octopus that Alex pointed out, argh! I was very happy though that I managed to spot an Imperial anemone Capnea sanguinea, which is an uncommon species. The photo of this all-white individual was taken without a strobe; I really should have taken more time to get a decent shot. A good reason to go back though, and maybe we can spot some cannon balls then too. The water is 13-14 degrees and so it is still doable to dive with a wetsuit.