Blue sharks

This Monday I was lucky to be invited to join several colleagues for a trip to find Blue sharks with Chris and Annabelle Lowe of Atlantic Diver. Blue Sharks Prionace glauca are not uncommon around Cornwall at the end of summer but they are a pelagic species and usually do not come close to land. We left at 8:00 from Newquay harbour to go 20 miles offshore, get in a cage and see what would swim up! Chum was made by cutting up mackerel and mushing it in a bucket with a spade, out at sea, it was hung overboard in bags to create a trail. On the way I saw my first ever Sunfish Mola mola; a tiny one (30-40 cm or so) flapping about on the surface. We also saw a variety of seabirds: European storm-petrels, Fulmars, a Great skua and Gannets attracted by the chum. The picture above was taken at the end of the day when the weather was a bit more settled, but it was quite rough when we were on board. Let’s say I added a bit to the chum trail! The Fulmars are supposedly a good indicator of sharks, as they are the firsts to fly off. Not this time though, we spotted a small Blue shark (a bit over a meter in length) but all birds seemed oblivious to it. I had expected for the shark to be a bit closer to the surface, but it remained 5-10 meters deep and was quite hard to see. We took to the cage in pairs. It was bobbing about quite a bit and the water was flakey with mushy mackerel. The shark swam in big circles around the cage, once or twice it touched the cage but otherwise it kept her distance. We believe we saw a second shark of about the same size, but they did not appear together. The slender profile and deep blue colour of the sharks were very striking. One of the sharks had a parasite trailing from the tail fin, probably a copepod. The cage might seem a bit overkill for these sharks (there are two tour operators on the south coast who go out on trips without one), but perhaps not when considerably bigger specimens could also turn up (see this link for a recent angling record) and there are multiple confirmed Blue shark attacks on humans. The swell and ‘mackerel snow’ made it hard to focus, but more frustratingly my camera let me down once again by being unresponsive, so I have to really send it out for repair. I also brought my GoPro (one of the old models without a viewfinder unfortunately).  The longer first clip does not show the shark all the time (GoPro switched its software from ‘Studio’ to ‘Quick’, and whereas it is now easy to add a generic dubstep soundtrack, editing out bits does not seem possible) but gives a good impression of the experience nonetheless. All in all it was a great outing and I hope to go again some time. Many thanks to Chris and Annabelle, a very friendly and knowledgeable couple who are highly recommended for their sea safaris!

 

Raglans Reef

It has been a long time coming, but I finally managed to go on a boatdive to the Manacles this weekend. I rented my gear at Seaways in Penryn and got on board the Atlantic Scuba rib ‘Stingray’ in Mylor Marina. Nine divers were on board; I was teaming up with Thomas and his intern Andy from HydroMotionMedia (make sure to check out the revamped website), who are working on a documentary about Marine Conservation Zones (the Manacles are one). The Manacles are a group of rocks east of the Lizard peninsula about half an hour by boat from Mylor which historically have claimed many ship wrecks, and they form one of the best dive sites in the UK. The name is an anglicization from the Cornish ‘Meyn Eglos’, meaning church stones. It was a beautiful sunny morning, and when we were close we spotted several Common dolphins Delphinus delphis, who came up to the boat, an awesome start! At slack tide, we descended to about 18 meters to inspect the walls of Raglans reef, the outermost pinnacle of the Manacles group. For the first time, I saw many of the species I was familiar with only from the internet and books with my own eyes: Cuckoo wrasse, Dead men’s fingers (a soft coral), Ross coral (which is not a coral but a Bryozoan), enormous amounts of Feather stars (see this recent post when I found them first on holiday in France), Sun stars and of course the incredibly pretty Jewel anemones Corynactis viridis:The photos are OK but I could do a lot better, this was in part due to my camera malfunctioning for a bit and my dive was pretty short anyway, as I guzzled too much air (I need to do some sports and drink less beer!). Also, I need a lot more practice with video light and strobe. However, this dive was primarily about checking out the new scenery.  Some shots of other species below: the Edible sea urchin Echinus esculentus, Elegant anemone Sagartia elegans (variety rosea) and Dead men’s fingers Alcyonium digitatum. I hope to go back to the Manacles on the Stingray very soon!

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

Whitebait

This Friday at the Seven Stars pub in Flushing there was a lot of activity in the water. Huge shoals of Sand smelt Atherina presbyter ((EDIT or potentially Herring….very difficult to make out!) were chased up the slip by mackerel. The shoals were so dense you could scoop the fish out of the water with your hands and shed fish scales were shimmering everywhere. I quickly picked up my camera from home down the road and stuck it underwater. With the fading light (and two kids to take care of) the filming was hurried and not ideal, but still gave a nice view of the frantic activity.

 

Feather Stars in Bretagne

Last week I was on holiday in Bretagne (Brittany), France. There was not a lot of opportunity for snorkelling or rock pooling activities, but the last day I checked out the pontoons of the large marina in Trinité-sur-Mer. I was not disappointed; the pontoons in Cornwall are full of life, but these ones 200 or so kilometers further south were exceptionally diverse. The most striking find was that of orange, red and purple Rosy feather stars Antedon bifida. These also occur in the UK but I had not seen these yet here so I was quite excited. I did not go into the water myself and the photos I took holding my camera under ended up being not great so I took some shots from above water as well, too bad I did not have more time!The first photo below gives a good impression of how abundant and diverse life attached to these pontoons is. Many species are the same as the ones I see in Mylor marina, including invasive species such as the Bryozoan Bugula neritina and the tunicate Styela clavata. In addition to the many sponges, anemones, mussels, oysters and colonial tunicates I even saw things such as scallops (not sure which species) and urchins (Psammechinus). The peacock worms were absolutely huge. The plumose anemones Metridium senile looked different to the ones I am used to here to with orange individuals having brown collars which sometimes were really big and wavy. It seems no one that moors their boat in a marina ever takes notice of what is attached to the pontoons, but they should, as the diversity and beauty can almost rival coral reefs. I hope I can go back one time to properly investigate but for now I will check out the local marina’s and keep an eye out for feather stars…

Aquarium Update 17

I started this blog mainly to document keeping a temperate marine aquarium; browsing back I see that that was more than four years back already! (see this introduction). Over time, I became more passionate about rock pooling, snorkeling and diving, specifically about seaweeds and photography, and blogged less and less about my aquarium. The aquarium had its ups and downs, as coldwater aquariums tend to be a bit more trial and error (coldwater marine aquariums do not consist of relatively slow growing stony corals as in tropical marine aquariums and house much more (higher order) diversity than tropical or cold freshwater aquariums). Also, I am a lazy man. The last aquarium update was from last November and the aquarium did not look that great, but I have lately spend more time on it and it looks much better now, so here a quick new post.I bought an upgrade Red Sea Max pump (much better) a while back, and more recently a Tunze 9001 skimmer (MUCH better than the stock skimmer, removed  years ago as it was so noisy). The only problem is that the pump is so powerful that the water does not get sucked fast enough in the back compartment and it starts to run dry, I need to think how to fix that. The water is very clear though. I only have Cornish suckers as fish at the moment, and it might not be safe to add other fish as there are quite a few anemones at the moment. I have collected a bunch of Daisy anemones Cereus pedunculatus whilst diving (these are very common here in Flushing). I feed all my anemones small pieces of defrosted prawn by hand, these little ones respond very well to that and I hope they will grow much larger. I also collected some more Redspeckled anemones Anthopleura balli (below). David Fenwick kindly gave me an oyster with many Jewel anemones Corynactis viridis attached (crappy pic, sorry). These did relatively well for a while when feeding fine dry foods (sold for reef aquariums) but they were bothered by the squat lobster and cushion stars and I put the oyster back in the sea (I was also worried the oyster might die and cause a huge nitrogen spike). As an experiment I removed a few jewel anemones with a scalpel and superglued them to frag plugs but they did not survive. Ah well, that might have been a first, so worth a try. With a smaller, dedicated aquarium with better filtration (to deal with many small food particles) it must be doable to keep these. At the moment there are several species of gastropods, a cute little clam, mussels, Snakelocks- Dahlia-, Beadlet- and Strawberry anemones, a small Hairy crab, Cushion stars, green urchins and a Common starfish. The echinoderms seem easiest to keep of all. I actually put the common starfish back as it was picking of all my snails which I need to keep algae in check (and are interesting in their own right of course). I added a Cushion starfish with six legs though (‘Dave’). Hopefully I can find some more anemones when diving over the summer and who knows experiment with seaweeds again.

Falmouth Seaweeds July

Last week I went for a little swim at the usual spot at Castle Beach. The viz was nowhere near as good as last month, but still OK. There are schools of sand eels and sand smelt and I even saw an eel. The contrast between growing brown seaweeds and withering red seaweeds has become even greater. Below you see some yellowed Harpoonweed and a ‘forest’ of Thong weed covered in epiphytes. As the light was a bit subdued, I focused on the most shallow area. The bare parts of the rock are covered with barnacles, dog whelks, sting winkles and limpets. The seaweeds are mainly Serrated wrack Fucus serratus, Sea lettuce Ulva, Grape pip weed Mastocarpus stellatus, some Ceramium and Laver Palmaria palmata, as well as Dumont’s tubular weed Dumontia contorta.

more diving

diving silver stepsLast Wednesday I went for a quick dive at Silver Steps in Falmouth, good viz and the water is no longer cold. Buddy Chris (above) and I rummaged around the U-boat wreckage (less impressive than it sounds) and unfortunately did not see any cuttlefish. What was new was a largish Topknot Zeugopterus punctatus which was gone before I could take a decent photo. I also saw seacucumbers for the first time diving (have seen them before when rock pooling, including parasitic snails). They could be Pawsonia or Aslia, but with the bodies wedged in the rocks and only the feeding tentacles visible it is not possible to tell. Sand eels were abundant and Sand smelt Atherina presbyter were also present at the surface. I hope to go back soon to practice with the strobe. I did a second dive in Flushing with Thomas too. Enjoyable but not too many great shots. I included one of Sand mason worms Lanice conchilega and fan worms Megalomma vesiculosum.

Swanpool

OK, as I mentioned in  the last post, I had been on three dives before my exceptional viz snorkel session but did not have the opportunity to post pictures. So here goes for the first dive at Swanpool with Thomas Daguerre. Swanpool is a nice little beach but I was sceptical about it, as it is mainly, well, beach. Thomas wanted to try to find some sand-dwelling creatures though and I was up for trying something new so in we went. See him at work below in some seriously murky water! Again, spider crabs were common, sitting still but running away when getting closer, stirring up the sand. There is some sparse seagrass, arranged in thickets parallel to the strandline, some Sand mason worms Lanice conchilega can be seen in the foreground. A Spiny starfish Marthasterias glacialis was eating up a Pod razor shell Ensis siliqua. A little swimming crab hid in the sand, not sure which species.Also, jelly season has started, I saw several Northern Comb Jellies Beroe cucumis. They are exquisitely beautiful and very hard to focus on, which makes for a photographers nightmare. Apart from a Compass jellyfish, I noticed a Blue jellyfish Cyanea lamarcki. It appears to have two parasites, which could be the amphipod Hyperia galba. All in all not a bad dive. Also, I found a frisbee and a decent pair of sunglasses!