Blue sharks

Posted on September 8, 2017 by An Bollenessor under fish, GoPro, snorkeling

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!

More Pontooning

Posted on October 25, 2014 by An Bollenessor under bryozoans, Canon Powershot D30, cnidarians, fish, GoPro, hydroids, pontooning

Went back today for some more peering from the pontoons in Mylor Bridge marina. Besides the Thicklipped mullet and Two-spotted gobies, small schools of Sand smelt Atherina presbyter were out and about. A short clip of this silvery, pretty fish made using the Canon Powershot 30D and after that a clip made with a GoPro 3+ (not in HD as it was my 2nd, free upload)):

(Annoying that wordpress makes the 2nd clip smaller!) I managed to find back the single 1 cm Elegant anemone Sagartia elegans mentioned in the last post but again was unable to remove it; seems like this species knowns how to attach itself a bit better than do Plumose anemones. I noticed that besides the tunicates, sponges, bivalves (mussels and oysters), seaweeds, anemones and peacock worms, hydroids and bryozoans are also very abundant. I still have to educate myself a bit about these groups. The peacock worms would be beautiful for the aquarium. Although they would be easy to dislodge, it would be problematic to fasten them to something again. Maybe I’ll find a small object with some attached when I’m diving that I could take back some time (frozen artemia might be too big for them to eat, so I would need to look at artifical plankton products for food).

GoPro

Posted on September 29, 2014 by An Bollenessor under fish, GoPro, photography

A few weeks back I ordered a GoPro Hero 3+ Black Edition, a tiny video camera that is especially popular amongst those that jump of cliffs etc. It comes with a housing that is waterproof up to 40 meters and has excellent video quality. The still images are not so great, you cannot focus or zoom and there is not even a display, although there is an app to control the GoPro using a phone which is very user friendly (the wi-fi connection however is lost as soon as you submerge the camera so you cannot use the phone display to set up underwater shots unfortunately). Of course I will try out the GoPro for diving, but I do not have very high hopes, as there probably will be loads of shaky footage under bad light conditions. Instead, I thought it would be cool to use the time-lapse function in rock pools. I was inspired by the following video:

(For two cool starfish time-lapse films here and here; the BBC ‘Life’ documentary of course is the cream of the crop.) I clipped the GoPro to the plastic baseplate it comes attached to in the packaging and strung that to a lead diving weight using a tie-wrap. The first time-lapse movies turned out OK-ish, the actual video is more impressive quality-wise. It is fun to see all the little gobies but it is obvious that they are not in focus when up close (and too small further away), so probably it is a good idea to bring some frozen artemia to lure them to the best spot. It is obvious that time-lapse works best for slow moving animals such as starfish; fish just flash by, although the nice thing is that you discover that there are many more fish around than you would think from just glancing over rock pools. Actually, it might be nice to try some slow-motion movies of fish using very high frame rates. The short clips I made are not good enough yet too post; the water was full of bits of seaweed, it was quite cloudy and the rock pools in general do not look as nice as they do in spring (lame excuses I know but see the picture below taken at Falmouth a couple of weeks back: it definitely does not look like this at the moment!). I also need to think about different subjects, as macrophotography is not really an option (although this lens might go some way).As a small consolation, I have added two videos from when I was rock pooling in Cameroon a couple of years back (this is a bit of an unusual holiday destination but highly recommended!). I made them using my now defunct Panasonic Lumix (DMC-F10) in very shallow water (<10 cm). Unfortunately I do not know what species of fish these are but they look like awesome aquarium fish (not too many people with a West-African marine biotope aquarium I reckon). The Lumix is not known for great macro but these vids are not bad (I fear this type of movie will not be an option for the GoPro…). I hope to make some cool GoPro videos soon and post them here!