Showing posts with label sponges. Show all posts
Showing posts with label sponges. Show all posts

The Écréhous

Posted by Graeme Lyons , Wednesday, 17 September 2025 17:25

This time last year, I had never even heard of the Écréhous. Now I have been lucky enough to spend two days and nights there snorkelling and rock-pooling, all courtesy of Nicolas Jouault. I literally went on holiday from my own holiday. The Écréhous are some small uninhabited islands and rocks in the sea off the north east coast of Jersey, not quite half way to France. It falls under the Bailiwick of Jersey, and therefore counts on your pan-species list! Along with the abyssal plain off the western coast of Ireland, this is one of the areas we decided counts that few pan-specie listers, if any, have ever recorded in. Now the key target for the entire Jersey trip was the nudibranch Berghia coerulescens. I'll come back to that. Oh and I started with my favourite photo from this trip, a stonking male Black-faced Blenny (by far the commonest fish there). Look at that dorsal fin!

Here's Nick loading up his boat.


Leaving Gorey Harbour past Mont Orgueil Castle. It was a pleasant and uneventful crossing, with a few Manx Shearwaters and terns the only wildlife.


Although I could see the Écréhous from the actual room of our accommodation at Bouley Bay, this was my first proper view of the islands.


The main clusters of huts on the Écréhous. It's an incredibly unusual place.


Here's the view looking back towards Jersey. When the tide went out, we went out snorkelling just in front of the end of that rainbow.

I was really lucky to get out there at all. The ferry on the Wednesday was cancelled, Thursday fully booked (and alas, also cancelled) and the next one wouldn't get us in until Friday afternoon - too late for the Écréhous. So we went a day earlier. Hence why the holiday just kept getting longer and longer. 

We snorkelled on days one and two, and rock-pooled on the last day due to higher winds. This is really the first proper snorkelling I have done and it was a steep learning curve. Turning rocks in a foot or two of water is really interesting, it's like being in zero g, you have to think a lot about the physics of it all. I also learned that the annoyingly high temperature I always run at steams my goggles up and I have to wipe them every 15 minutes or so. This is a radical change for me, the first time I got in the water was only last September. I was terrified of putting my face in the water after being a poor swimmer my whole life. I must admit, I am much more comfortable when I can see the bottom. Now you can't get me out of the water, it's like I have grown gills. I think we did three hours each time and it seemed like less than an hour.

Anyways, I'll start with the fish. I was playing around by the jetty before we headed out and I spotted a fish, more importantly my 99th fish! Common Dragonet! These are beautiful fish up close but they were not easy to get close to.

We saw a few Topknots. I was just using my TG-7 here and the light was very bright above with a light breeze, leading to these rainbow like bands. I needed to cast my shadow over the subjects but I don't have the light setup for that.

Then I spotted this tiny fish with an odd fin near the front, I did not realise at first that this was a young Black-faced Blenny. Until I went on to see dozens on them! Just look at these beauties. My 100th fish!

Moving to a new area we swam over these young Black Sea-bream!

On the second day there were some small areas of Eelgrass in the pool we were snorkelling in. It looks amazingly beautiful under the water when floating vertically.

As I swam around the corner, I came face to face with a shoal of young Pollack. It was beautiful. But wait, there's something different in with them!

In fact, in this shot you can see three species. Pollack above, more young Black Sea-bream in the middle I think (although they are much plainer and buffier than the ones above) and below a Striped Red Mullet! Yet another lifer, fish species 101!

This Lobster was a bit of a shock, I was rather pleased to get my face away from those claws.

Time for some nudi-action. The commonest sea slug there by far was Pruvotfolia pselliotes. A beautiful sea slug with a hateful scientific name like a pile up in the mouth. Try saying it with a snorkel in your gob! I love the tiny white spots on the mantle. The cerata sometimes look like sparrow's wings.


A few of these large Geitodoris planata were quite impressive.


So, are you ready for the money shot? I give you, Berghia coerulescens. Yeah, we only found the eggs and then just one spiral. Despite ten days of constant rock-pooling and snorkelling, it seems the population has crashed just a couple of years after they turned up on the islands. In PSL terms, we count all stages (I have ticked Kentish Glory from its eggs). If it's good enough for a record, then it's OK on your list BUT I still feel like I have not seen the species. I will have to go back out to Jersey soon! It's always good to leave one thing you didn't get (would rather it hadn't been this species though).


While I am it, based on the nudis Nick has been seeing out there, I am pretty sure these are the eggs of Atagema gibba (an out of water shot).

Some other molluscs. Green Ormers are such wonderous things under the water and quite fast for molluscs. 

Here's one of Nick's 'tagged' ormers. Nick tirelessly monitors different populations here and on Jersey. Recording dates, size, survival rates etc. Really important stuff for monitoring long term population trends.

I finally caught up with the smaller Lamellaria latens with its spotty underside to the mantle.

There were quite a few of these tiny, whitish, grub-like chitons which I identified as Letpochiton cancellatus.

The islands are really amazing for sponges, it's a Jackson Polack down there. Nick showed me most of these, so I hope I have got the names all right here. I think from top to bottom; Polysyncraton lacazei, Raspailia ramosa Chocolate Finger Sponge (if you left some chocolate fingers in a damp cellar for 25 years then maybe - guess it's just starting out), Chelonaplysilla noevus, Aplysilla rosea and Clathrina rubra.

On the last morning, we went rock-pooling in a a different area. Nick caught this Giant Goby! It was huge.

I turned a rock to find this large crustacean. I first thought it was Upogebia deltaura but Nick pointed me towards Axius stirhynchus. This burrowing crustacean is rarely recorded. It was interesting watching the appendages under the abdomen paddle away in the Ferrero Rocher box. My camera lens was a mess from the previous day's snorkelling, so these images are heavily edited.

Time to head back to Jersey. What an insane trip, it was one of the most memorable experiences of my life! I am eternally grateful to Nick for this. Especially as it has given me the confidence to get in the water on my own.

In fact, I was straight in the water at Bouley Bay. Although I learnt the hard way that five days of stubble lets water seep into your mask. Here is a young Barrel Jellyfish there!

And a brief attempt at Rozel where I managed to catch a Shanny with a bum bag. Imagine being that derpy.

And finally, the sea was pretty rough on the way back on the ferry to Poole, and as it doesn't stop at Guernsey any more, it went up the east side of Jersey, right by the The Écréhous! I took great joy telling everyone who would listen on the ferry about my time there. 

I have one more Jersey post in me about the terrestrial side of things but that will have to wait until next week.

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Planet of the Nudibranchs!

Posted by Graeme Lyons , Tuesday, 29 July 2025 11:23


I've just got back from a very exciting and spontaneous two-day stay on Anglesey. It involved what it best described as an avalanche of nudibranchs! It's all down to my friend Mark Colvin (and his daughter Charlotte). I had a weekend free for the first time in years and was planning to go to Cornwall. I was feeling rather discombobulated after having my first full blown migraine in 30 years on Friday morning, when Mark sent me a text saying he had just seen 23 nudibranchs of some eight to ten species! I got up the next morning, booked a B&B and was there by 4.00 pm for the next low tide.

Directly under the Anglesey side of the Menai Bridge is somewhat of a nudibranch hotspot. Indeed, I saw at least seven species when I was there. So, put on your breathing apparatus, set phasers to stun and prepare to be beamed down to the Planet of the Nudibranchs!

First up (and this is perhaps the commonest species there - albeit I have only seen this once before on Jersey) is the widespread Facelina auriculata! The iridescent blue/purple and long, gracile nature help to distinguish it from Facelina bostoniensis.

I am pretty sure this one was Facelina bostoniensis which was also present there in numbers. I have only seen this once before at the Pound.

I think this is also bostoniensis with eggs.

After the Facelina, Edmundsella pedata was the commonest, with more than 10 found under one rock grazing on hydroids (I will come back to this rock later). These are incredibly wonderful animals. Common on Jersey, I first saw this on the Isle of Wight but I have never seen it in Sussex.

Polycera quadrilineata (it's likely this and not norvegica based on the rhinophores and other factors but it's not easy to be 100% sure on this).

I found a mature Sea Lemon Doris pseudoargus. The others put it in a container with some of the other species, so you can see here how much bigger they are!


I found one Palio nothus under a rock too, I have only seen this on the Isle of Wight before but it seems a common and widespread nudibranch.

Yet amazing as this was, I was lacking a sea slug new to me! Dopamine deficiency was kicking in. So I went back for the low tide on Monday morning before I left Wales. The tide was coming in when I stumbled on the rock with all those grazing Edmundsella under. I thought I would count them using my close-focus binoculars when I spotted a totally different colour. There, poking out of the darkness of the hydroid forest, were a dozen bright orange-red, brilliantly white-tipped flares! There were also white highlights on the tentacles and rhinophores and not a suggestion of pink on the body. The rhinophores were also lealy not annulated like Facelina. This was a lifer! BUT it was under 4 mm and hard to get to.

I did eventually get it in a tray for a closer look and I soon came to the conclusion this was Microchlamylla gracilis (thanks to the amazing field guide). My 15th species of nudibranch in the British Isles! Nearly half of all the species I have ever seen I saw at this site in one weekend. Bonkers!


Sublime! We saw over 50 individual sea slugs on Saturday night, and they had at least two species on Friday night that I did not see (one of which I have never seen). I will therefore be back. 

There was some other nice things there too. Like Lightbulb Sea Squirts (still scarce in Sussex).

Some Boring Sponge. It really is boring.


And lots of these hydroids, Entopleura larynx. . There are sea slugs that eat just this and it seems that the other saw one of these on Friday night! How exciting, I love to come away seeing lots of stuff but not everything as it leaves me wanting more! A massive thanks to Mark, Charlotte and all the others who came out! 

Now I did a lot of other rock-pooling, snorkelling and entomology around the island in 48 hours but I will leave this for another time as it has been 15 years since I last visited the island and some 22 since I lived there, so I would like to do it justice. Now I'm off looking for rare mirids...

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