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!

 

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 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.

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:

Falmouth Seaweeds: Mid-April part II

Above an illustration of the decline of seaweeds: Juicy whorl weed Chylocladia verticillata all white and fuzzy (see for a more healthy looking plant this post from 2.5 months ago) on a bed of the common and pretty Discoid fork weed Polyides rotundus. There seem to be around 25 or so  (larger) species that are common in these pools. Many of them can be seen in the two photos below (including a stray Bladder wrack, a species that dominates the shore just a meter higher): Below, a whole bunch of individual species. First, Sea beech Delesseria sanguinea, which must have washed up from under the kelp beds (too bad I did not get the entire plant in frame…). Second, a photo of Ulva with Chipolata weed Scytosiphon lomentaria. Third, the brown Divided net weed Dictyota dichotoma. Fourth, Slender wart weed Gracilaria gracilis. Fifth, False eyelash weed Calliblepharis jubata; this plant has grown quite large and has turned from dark red/brown to a much lighter brown. Sixth, the Falkenbergia stage of Harpoon weed Asparagopsis armata (see the third photo) on the right. Seventh, Red grape weed Gastroclonium ovatum. Finally, two photos of my favourite species the blue Bushy rainbow wrack Cystoseira tamariscifolia.

Falmouth Seaweeds: Mid-April part I

Less than 12 hours back in Cornwall and I managed to slide into the rock pools at Castle Beach in Falmouth this Saturday to see what the seaweeds looked like. There was a noticeable difference with only a week ago. The speed at which seaweeds grow, and decline, still amazes me. I managed to take my best photo yet, of Red rags Dilsea carnosa (surrounded by a whole bunch of other species), above. I made so many photos that I will split them over two posts, with some general ‘seaweeds scapes’ here and with individual species in the next post. The Sea lettuce Ulva has been taking over parts of the pools, turning it a bright green. The reds of the Juicy whorl weed and Berry wart cress and pink of Harpoon weed are less bright, and the Red grape weed and Fern weeds are turning ‘fuzzy’. Still, the seaweeds are much bigger and cover most of the seabed and it looks very exuberant. The Wire weed and the Thong weed (or ‘spaghetti weed’) Himanthalia elongata have been rapidly growing; the latter consisted of ‘buttons’ in January and are now a meter long, so must grow around a centimetre a day. The fronds are covered in flakes (which must be reproductive structures) that come off when you swim through them, clouding the water and so ruining the shot if you do not take it straight away. The sun came out more in the last photos, hence the different light (I have edited most (not all) photos slightly using standard Windows Photos, mainly by decreasing the highlights). More photos very soon!

 

 

 

 

Falmouth Seaweeds: Early April

A whole bunch of photos from last Friday, starting out with the prettiest ones depicting a whole range of species, most strikingly the crimson Gracilaria and blue Cystoseira. I was so pleased with it I shared it on the Seaweeds of the NE Atlantic facebook page and Frances Bunker, one of the writers of the highly recommended Seasearch Guide to Seaweeds of Britain and Ireland, kindly uploaded a photo with all scientific names. This is a great idea and I should do the same for future posts (I have not done so yet as I am back home and did not bring the guide). As good as it is to be back in the Low Countries, I am missing out on being able to snorkel in some very good weather and likely better visibility than for the photos in this post. The rock pools have changed markedly since the last post a couple of weeks back, with hardly any patches left without seaweed growth. The colours have changed too, with much more of the green Ulva, and more brown (e.g. Calliblepharis) relative to reds. Some seaweeds seem to be in decline already (e.g. Gastroclonium) while some are more prominent (e.g. Palmaria). Below I have posted a range of photos, some are pretty good, others not so much, but they give a good impression of the diversity (most photos have at least ten species in them but I have not gone through the trouble of typing all the names): I have no clue what the brown, thin, frilly species is above. Below some individual species, first Dulse Palmaria palmata and Sea flax weed Stypocaulon scoparium. Not 100% sure about the next three: Dumontia, Lomentaria and either Laethisia or Colpomenia (I should know this…). Finally, some photos taken under the cover of Thongweed Himanthalia. More photos next week I hope!