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.
High time for a snorkel, and few better places in the area than ‘Silver Steps’, between Castle Beach and Pendennis Point in Falmouth. I took my little Lumix camera (goes up to 10 meters deep, no optical zoom) with me to take some sub-standard pics (all other photos on the blog are taken with my iPhone). This site is a mix of rocks covered in kelp and gravel and even the remains of two U-Boats (they are no longer recognisable as such though, see here for more specifics on these and other wrecks off Falmouth). There is always something to see: schools of Smelt chased by Sand eels, hovering Two-spotted gobies, Corkwing and Ballan wrasse, Spiny starfish and loads of seaweeds. In fact, there was so much to see that I have divided the pictures over two posts. First a photo of the site and some of the U-Boat wreckage:
We were in for a nice surprise: a good-sized John Dory Zeus faber at around seven meters depth. I have posted a very nice picture from my first and only dive in Cornwall courtesy of Charlotte Sams, but here a short, jittery video as well:
Anyway, a perhaps even nicer find were Leopard-spotted gobies Thorogobius ephippiatus. Some sources make it seem like this is a rare species only ever encountered by divers, but it is actually not uncommon and we saw them at two meters down (the tide was low though). It is a shy species that lives under ledges, burying between the rock and the gravel. The picture is crap but also proof I am not lying. The next picture is of a Tompot blenny Parablennius gattorugine peeking from a crack in the rocks. Large snakelocks anemones are everywhere on the kelp, and although a month ago I saw none, many of them again housed commensal Leach’s spider crabs Inachus phalangium. (These anemones and crabs do well in the aquarium btw, see here.) It would be interesting to know if these crabs arrive from deeper waters or just grow up really fast.
It has been a while since I last posted about the aquarium, mainly because I had a problem with algae and did not like the look of the tank in general. Combined with being away for two weeks over the holiday season, I decided to remove the rocks and most animals from the tank. Only left are some snails, Cushion stars and a Spiny starfish (who seems to do fine except for being less brightly coloured than when I caught it). The snails made a good start and cleaned up a lot of algae but it was too little too late. Also, (non Spiny starfish-related) mortality was quite high. Of all snails, the periwinkles fared least well (as I had noticed on earlier occasions); the Grey top shells seemed to do best. A main problem is that the snails move out of the water and often die there. Grey top shells can be found in the intertidal but are also common in the subtidal and so might be more suitable for the aquarium.
Anyway, time for a fresh start in the new year. I have decided to buy a chiller (and pump), mainly so I can switch off the noisy hood fans, but also because a more natural temperature regime might help keeping some of the more difficult species (see eg here and here). I have trawled the internet to find recommendations for the least noisy chiller but to no avail. I will stick with a more expensive brand and hope for the best. I will also invest in LED lighting. LED lights give a nice shimmer effect, generate less heat, use less electricity, need less replacement and are more easily dimmable. I’ve found this interesting Red Sea Max 130D retrofit kit:I will need to buy a separate dimmer and probably will have to ask my local sparky for help fitting it in the hood but it seems like a good investment. I’d like to supplement white LEDs appropiate for shallow water with some blue ones so I’ll be able to get a deeper water feel as well. This week I saw an inspirational aquarium back in Blijdorp Zoo in Rotterdam: a deep water reef with gorgonians, many brittle stars, Boar fish (or Zulu fish) Capros aper, Snipe fish Macrorhamphosus scolopax and John Dory Zeus faber. A crap photo:
However, I will go for a more brightly lit seaweed aquarium first. I will switch to finer gravel and reduce the amount of rocks to improve water flow. This time I will also focus more on fish. Marius has a great picture of a Two-spotted goby Gobiusculus flavescens in his Irish rock pool aquarium here and I definitely want to have a couple of these (I had a tiny one recently but it was eaten by one of the Snakelocks…). The other fish I definitely want to have is a bright green juvenile Ballan wrasse Labrus bergylta (although the other species are pretty too):
Small wrasse can be caught using a hand net but I reckoned it would be easier using a cast net. After my first trial run with such a net in the Helford river a while back I am not so sure though: loads of leaves and twigs but no fish. Youtube has hundreds and hundreds of ‘how to throw a cast net’ videos but these all use slightly different techniques which sometimes involve a throw whilst holding the led line between the teeth… Anyway, I’ll have to practice!
A couple of weeks ago I went for a bit of a spur of the moment after-work dive with colleague Andrew (like me a quite unexperienced diver) and his friend Charlotte Sams. Charlie is an experienced diver and natural history photographer, who has her own blog: Charlottesamsphotography, which you should check out. We dove in Falmouth off Pendennis point. The water was not very clear (maybe 5-6 meters visibility) but the temperature was quite nice. We saw (amongst others) Sand eels (do not know which of the two species), Pollack Pollachius pollachius, Dragonets Callionymus lyra, Two-spotted gobies Gobiusculus flavescens, a Tompot blenny Parablennius pararugine, very large Ballan wrasse Labrus bergylta and a beautiful little John dory Zeus faber:
We also saw some very large Common starfish Asteria rubens and also a nice Spiny starfish Marthasteria glacialis. We dove only to about 5-7 meters, which meant we could stay in quite long, over an hour. At seven meters, the bottom was a sandy expanse, interspersed with mounts of Laminaria Kelp covered in hydroids. In-between the kelp were other seaweeds, such as Red rags Dilsea carnosa but I was more focused on the animals during the dive. In shallower water were enormous bundles of Wireweed Sargassum muticum (also known as japweed but that is not very pc…) and the very long slimy Mermaid’s tresses or Bootlace weed Chorda filum. Snakelocks anemones were very common, and we managed to also see Leach’s spider crab Inachus phalangium, which lives associated with these anemones. All in all a fantastic experience, and I hope to find the time to go diving very soon again!
I have a love/hate relationship with public aquariums: love because I am a bit aquarium-mad, and hate because quite a lot of them really are disappointing. Of course, I know all too well that it is not easy to create (and maintain) good-looking aquariums. Also, the paying public needs to be pleased and it wants to see ‘nemo’s’ and sharks which often results in the same sets of standard tanks. Although I do understand the need to educate the public, I am quite allergic to all kinds of video installations and boring props taking up space that could have been filled with tanks. I am not even talking about walkways decorated with fake polyurethane caverns or ornamental treasure chests in tanks…
I try to visit public aquariums whenever possible and from now on will review them on this blog, specifically highlighting the smaller, temperate saltwater tanks that could serve as inspiration. Last week I was in Slovenia for work and a short holiday and passed by the lovely town of Piran which has a small (about 10 large and 10 small tanks) public aquarium, all with local animals. Here is one funky looking tank housing some writhing moray eels and Grey triggerfish Balistus capriscus, the latter also present in Cornish seas:
I am not so sure about larger-sized Mediterranean Sea aquariums, as there is not a lot of potential to make them visually appealing: some rocks and the odd human implement as decoration and the fish are often not overly spectacular (see the Two-banded bream Diplodus vulgaris below). If I were to go for a large, non-planted rock tank, I would try my hand at an African Great Lake aquarium instead, with the fish being more diverse, more interesting and more beautifully colored.
One of the largest fish on display was the Leerfish Lichia Amia. It was a shame to see such a large pelagic fish in a tank with its head completely deformed due to it bumping against the glass:
I was most interested in the smaller aquariums. These housed some species that can also be found in Cornwall, such as the Tompot blenny Parablennius gattorugine and the fantastic John Dory Zeus faber (which occurs around the globe):
Some of the small aquariums were quite sweet. No seaweeds to speak of (although I saw some Ball algae Codium bursa) but lots of nice invertebrates such as sea cucumbers, clams, whelks, sponges, anemones as well as a variety of fish:
Especially amazing was the stony coral Astroides calycularis:
A Small rockfish Scorpaena notata:
All in all an interesting little visit (I had to rush a bit taking pics as the rest of the family is not as keen on ‘the mysteries of the deep’ as I am…). Lots of types of invertebrates that I would like to try to keep such as sea cucumbers, but for the moment I will focus on seaweeds. I had no time to have a proper look at the rocks outside (the Mediterranean has very small tide differences anyway) and I had not even brought my snorkel. From the glances I got, the Adriatic coast did not have much on the Cornish coast though!