The Cornish summers are anything but predictable. One day I’m sweltering in shorts and beach shoes and the next I’m shivering in waders and a thick jumper. Although the showers are back with a vengeance, there’s always something to be found if I can make it across the rocks without breaking an ankle.
My first outing is to the rocks beyond East Looe beach and I’m pleased to come across a new colony of St Piran’s hermit crabs on the mid-shore.
They’re becoming a familiar sight around Cornwall and I’m starting to recognise them from the tips of their red legs, before their chequerboard eyes and equal-sized claws emerge from their shells.
Dragging the family with me on my next expedition, I take a look at the other side of Looe.
At Hannafore, the rocks are hidden under a thick brown tangle of wracks, sargassum weed, and kelp making my feet slither with every step. It’s hard to make out where the pools are much of the time, let alone what’s in them.
Still, with some patience and careful sweeping aside of the long strands of weed, some treasures are revealed. This heart-shaped daisy anemone is the pinkest one I’ve ever seen.
As we wade in a long, deep pool a large fish passes between the fronds of sargassum near my feet. Moving slowly, I herd it towards a shallow corner, and, holding a bucket behind it take one more step. Nine times out of ten, I fail and the fish darts away never to be seen again. This time, the colourful fish takes me by surprise and swims straight into the bucket.
Here it is – is the first adult corkwing wrasse I’ve found in a rock pool.
Cornish Rock Pools junior comes over to admire the fish, talks to it and gives it a stroke. We look at its pouting lips and the iridescent blue stripes on its cheek, the typical colouring of the male corkwing wrasse. The female is much more dowdy.
After a few minutes, Junior lowers the bucket into the drizzle-spattered pool and we watch the wrasse swim free among the weeds.
I can see why most people see rockpooling as a fair-weather activity, but I’ve always liked the heavy calm of an empty beach on a foggy, damp day, and the animals are as colourful as ever.
If you read this blog regularly, you’ve probably noticed a pattern: I bimble about the Cornish rock pools looking for an exciting creature, fail completely, then find something unexpected. Well, hopefully you like the format because this week is no exception. I go on a quest to find fish eggs and discover this rare sea slug.
Fish eggs are amazing. If you catch them just as they’re nearing hatching you can see each baby fish staring out, its tail curled tight around its head like a scarf.
So, when Junior announces he wants to go for a big walk, I suggest Port Nadler. This slightly exposed rocky bay is ideal for Cornish clingfish. Their distinctive yellow eggs usually carpet the underside of the rocks and their developing babies are especially beautiful.
Only the tide today isn’t low enough to access the clingfishes’ favourite gully.
I look in the pools and lose count of how many rocks I lift. There don’t seem to be any fish eggs. As the tide drops a little further, I come across some Berthella plumula sea slugs and a sea hare.
There’s an anemone I don’t recognise. Translucent white all over with a base so wide it looks like a bowl. I later realise it must be the white form of Sagartia elegans (var. nivea).
Junior finishes his digging in the sand at the top of the beach and wanders over to join me. We lift a rock together and finally here are some eggs. They’re not the yellow clingfish eggs I was looking for, they’re smaller goby eggs, forming black-specked carpet of grey. Under the camera, the specks become a sea of eyes looking up at me.
I remember rockpool expert David Fenwick, who runs the fabulous Aphotomarine site, telling me a year or two back that there was a species of sea slug that specialises in eating these eggs. I peer into the greyness and see nothing, apart from a thin yellowish patch in the centre which looks like a piece of sponge or sea squirt.
I look some more. The eggs around the edge of the yellow patch look longer than the others.
I stare, stare some more then focus my camera on the patch and do yet more staring. Even then I’m not sure, but it could be…
It’s only when I see a tentacle move that I begin to see the slug properly. It’s over a centimetre long, but most of its body is covered in pointed cerrata the colour and shape of goby eggs, right down to the black dots that ressemble eyes.
This is the weirdly named Calma gobioophaga egg-eating sea slug. It’s the first I’ve seen and only the second record of this species in Cornwall.
The yellowish patch I thought was a sea squirt is the slug’s back. It’s covered in pale circles, which my books tell me afterwards are the mature gonads. Who’d have thought?
The books also tells me that the slug absorbs the fish eggs so well into its gut that it has no need of an anus. That’s right; it doesn’t poo. I’m not sure how that works, but it’s the sort of fact that gets Junior’s attention.
It’s not the easiest thing to photograph: a grey blob on a mat of grey eggs on a grey day in silty water. As I start to get my eye in to the outline of the slug, it glides towards me, feeling the eggs with its tentacles and swinging its long rhinophores forwards.
Tucked immediately behind each rhinophore is a distinct black eye, one of the characteristic features of this species.
The books suggest this species only eats the eggs of the black goby (Gobius niger), but slugs are not great readers and the other records from Cornwall and Brittany are, like this one, probably on rock goby (Gobius paganellus) eggs. In the Mediterranean this species has also been recorded on giant goby (Gobius cobitis) eggs. There’s another, closely related, species of sea slug, Calma glaucoides, that feeds on a wider range of eggs, including clingfish eggs and has been recorded in Cornwall too. Hopefully I’ll find that one soon!
The slug’s life cycle intigues me. As fish eggs are available for such a short period of the year, I’m not sure what happens to these slugs during the remaining months.
It comes on to rain heavily and as we’re already soaked from exploring the rock pools, we call it a day. I haven’t found a single clingfish egg, but, as is the way with rockpooling, I’ve discovered something even better.
There’s a questionable theory that 10 000 hours of practice makes you an expert and I may be close to ‘doing my time’ in the Cornish rock pools by now. However, I often feel I’m only scratching the surface of what’s out there. What better then, than to spend a few days on the shore with the genius that is David Fenwick, creator of Aphotomarine together with a fabulous group of fellow rockpool fanatics from Coastwise North Devon?
With layers and waterproofs aplenty, Junior and I joined them at Hannafore Beach, a site I know intimately, to see what new discoveries might await us.
I realised within minutes that I should have brought a notebook. David’s knowledge of marine species is immense and he wasted no time in finding signs of nematode worms living inside seaweed, reeling off their names. It was windy, drizzling and cold and to make matters worse Junior sprung a leak in his wellies, but there was no doubt this is going to be a fascinating day. Leaving Junior playing at reconstructing ancient ruined cities from the rocks of a mid-shore ridge, we waded across the lower shore.
Some species were familiar. The sea hares were everywhere and so abundant that it was impossible to avoid them. This swirling cloud of purple ink in the water was a sign we’d accidentally disturbed one of them.
Although Greater-spotted catshark (Scyliorhinus stellaris) egg cases are commonly found on parts of Hannafore we found more than I’ve seen before in this particular area, suggesting the nursery is more extensive than I’d realised. The eggs were at various stages from recently laid, smooth cases to bio-encrusted cases that had been in the water for months and seemed close to hatching.
Rob from Coastwise North Devon made one of my favourite finds of the day, this hairy hermit crab, Pagurus cuanensis, had some of the hairiest knees I’ve seen in a while.
David Fenwick was finding creatures at a dizzying rate. The speed with which he could pick out and name the different animals under each boulder was incredible.
Wading through the myriad colours of the seaweeds and past the many pretty Calvadosia cruxmelitensis stalked jellyfish clinging to them, we came to some rocks that are exposed to more current than some other parts of the beach. (Check out David’s brilliant Stauromedusae site to find out more about stalked jellyfish),
Under a deep overhang where I sometimes see lobsters, there was a small cluster of green and turquoise jewel anemones. They look more impressive when they’re open underwater, with little beads on the end of each tentacle, but I love the colours.
After a while, I spotted a colourful squat lobster, Galathea strigosa, scuttling across the back of an overhang and dived headlong in to retrieve it.
The wind on the pools was making it difficult to see much and my camera lens was steamed up, but we crammed in a last few minutes of rockpooling, looking at sea slugs, fish and hermit crabs before calling an end to day 1.
Coming soon – Part 2 of rockpooling with the experts!
Much as I love the Cornish rock pools, there are times – throughout the year – when the conditions are grim. According to the forecast, today is going to be one of those days. I have reluctantly cancelled a meet-up with Junior’s friends because the charts show the sort of gales and lashing rain that have most little kiddies shivering before they even reach the pools.
I don’t want to make rockpooling a traumatic experience for other people’s children, but I don’t think Junior’s aware that staying in is an option. He’s so well trained to enjoy the misery that at 10am he’s merrily pulling on waterproofs and wellies and grabbing a bucket. We’re off to ‘the gully’ and no amount of buffeting winds or ominous clouds are going to stop him.
We are climbing across the rocks from Plaidy beach towards our favourite spot when hail starts ricocheting off our buckets. We keep our heads down, turning our attention to the variety of colours in the pebbles. Junior crams his pockets with his favourites, the extra ballast helping to keep him upright against the howling wind.
The rocky gully is a little more sheltered if you crouch low enough. I adopt a sumo stance and waddle around checking rocks. Every single one conceals groups of worm pipefish, their bodies tangled together.
I’m taking photos of a blob, which is a stalked jellyfish marooned above the water-line by the big tide, when Junior announces it’s time to go ‘mountaineering’.
I feign deafness for a few more minutes, looking at crabs and urchins, but he’s persistent and soon I’m scrambling up a slope in the rock and attempting to follow him as he leaps across the sharp ridges and shoots down the steep seaweed-covered slopes to the next gully.
The low pressure and large waves are keeping the tide from falling as far as it might otherwise, so I’m wading to the top of my wellies when I find this sea slug, a Limacia clavigera. On the rock it’s formless, so I pop it in some water to take photos.
Junior returns from his latest expedition across the rocks telling me there’s ‘something I have to see.’ Inevitably, his find involves more climbing and some perilous leaps, which are a challenge in my clunky wellies.
The narrow gap in some huge rocks he’s discovered looks promising and Junior assures me it’s the most sheltered place on the beach. I suspect this might be a good spot for Devonshire cup corals and some other species which like strong currents. I won’t find out today though. The waves are exploding through the gap and the water in front of me is chest-deep.
We explore the pools. A rockling is splashing among the kelp and on the overhang, an Arctic cowrie is grazing. The damp weather suits shore creatures just fine.
The tide is due to turn so we start to gather up our things. When it starts to hail once more, I abandon taking photos of a beautifully decorated little spider crab and we clamber up the narrow cliff path.
As the downpour slows, we take a breather and look back over the rocks we’ve explored. The beach is completely empty, except for a pair of calling herons flying over. Somewhere a lone oystercatcher is trilling away. Despite his coat being wet enough to wring out (and I suspect his socks are too…) Junior declares the expedition a success.
The pools sparkle as the sun finally shoulders its way through the February murk. Beneath the surface, the seaweeds are sprouting up, the first sign of spring in the rock pools, and with them come the sea slugs. Many of these minute molluscs choose to spawn in the shallow waters around the shore, where their favourite foods such as sponges, sea squirts and seaweeds are abundant.
How they travel such distances to find mates and lay their eggs here is something of a mystery to me. They are delicate, squishy little things at best, and mere blobs of jelly out of the water. Once in the water, though, they reveal their colours and shapes, and most rockpoolers delight in finding them. Today, I see mostly pale, blobby ones rather than their spectacular cousins, but they are intriguing nonetheless.
I have ventured down a rocky gully that’s rarely accessible due to the pounding waves that surge through it. The overhangs are studded with Scarlet and gold cup corals, pinpricks of the brightest orange. Up close, I admire their translucent tentacles, wedging my head into the rocks to secure a better look.
Today, the unusual wind direction is keeping the waves at bay – just. The swell bubbles through a channel at my feet and every now and then spray is flung across the rocks onto my back. Places like this make me nervous and I’m constantly checking over my shoulder, expecting to be swept off into the Atlantic. As always, I forget all this as soon as I see an interesting creature.
In a hole under a rocky ledge beside a long pool is a white spiral of jelly. These are sea slug eggs and I know whatever laid them must be close by. After a minute of searching, I spot a blob on the rock and, taking great care not to squash it, I take it in my hand and pop it in a tub of water.
Before my eyes, the blob starts to unfurl. Its body takes on a more definite form and feathery antennae (rhinophores) extend from its forehead, while a frilled ruff of gills fans out of its back. Although it’s hardly the most colourful of the sea slugs, its creamy-white body has a pearly quality and its undulating sides make it look like it’s wearing layers of petticoats under its mantle. I am so absorbed in watching it I almost don’t notice the movement in my peripheral vision.
When I do look up, I almost slip off the rock in surprise. Emerging in a slow glide from its cave at the back of the pool are two vast black claws, followed by legs of a striking blue. Long red antennae are stroking the surface of the pool and I find myself staring into the eyes of a fully-grown lobster.
I’m sure you know as well as I do that lobsters don’t eat wellies, but when you’re on your own in a remote spot and one’s marching determinedly towards your toes, you start to question these things.
As your intrepid reporter from the Cornish rock pools, I know I mustn’t snatch my welly out of the pool, where it is dangling in front of those strong claws. Instead, I lower the container holding the sea slug onto the rock, flick my camera off the macro setting and start taking photos. I even manage a short video while the lobster, deciding that my boot doesn’t look tasty after all, backs into its hole and is soon lost from sight.
Moments like this take my breath away as only a close encounter with the natural world can. I remain staring into the pool for some time, a window into another world, until the rumbling waves remind me that it isn’t safe to linger here. Soon the tide will cover this pool and all its secrets once more.
Note: I have deliberately avoided specifying my location this week to keep Bob the lobster safe from harm!
“So is this a world record?” Cornish Rock Pools Junior has just found 26 stalked jellyfish and is feeling rightly proud of himself.
“It’s a record for Portwrinkle,” I tell him. “They’ve never been found here before.”
“But is it a world record?” he insists.
I take a moment to consider this. Only a moment, because my hands are frozen from holding my camera in the water and another snow flurry is starting.
“Yes,” I say. “You now have the world record for finding stalked jellyfish in Portwrinkle.”
From the leaping and cheering, I’d guess he’s satisfied with that.
If you follow this blog regularly, you may be starting to find the recent focus on stalked jellyfish a touch tedious. You wouldn’t be alone. Although I remember the excitement of finding my first one, the beauty of its markings and delicate tentacles, after seeing scores of the things and spending hours in freezing pools staring into the seaweed, they’re losing their edge.
Still, given that one species is a recognised feature of my local Marine Conservation Zone and two more species have potential to be added, any evidence that they’re here might help to protect them. So far, all of that evidence has come from beaches in walking distance of my home in Looe because I’m pretty much the only person recording them. When I took Natural England on a stalked jelly hunt at Hannafore, they asked if I could help them search beaches at the opposite end of the Looe and Whitsand Bay Marine Conservation Zone.
It seems such a great idea. Leaving home in a snow flurry though, I begin to question my sanity. I’m not sure, in such circumstances, whether it’s a good thing to have a wonderfully supportive partner and son, but neither of them bat an eyelid at the weather. Wearing boots, waterproofs, scarves, hats, gloves, and just about every item of clothing we possess, we head for Portwrinkle beach.
Junior becomes less supportive when I find the first stalked jelly. I hadn’t realised how badly he wanted to find it himself and wish I’d kept quiet about it, but after 45 minutes of fruitless searching it seemed like the sort of breakthrough worth announcing.
“I’m useless,” he sighs. “Now I won’t get the world record.”
I try to reassure him. Surely we are a team and finding them together? But nothing is working. A little further down the rocks, where the pools meet the sea, I notice an arc of rocks forming a shallow, rock strewn bay with plenty of weed.
“Come and try over here,” I suggest.
He kicks at the rocks and mopes over to where I’m standing.
“Just try,” I repeat.
It only takes a second.
“Here’s one,” he screams, his voice easily reaching his Dad, in the distance across the rocks.
Seconds later, while I’m crouching to photograph his find, he tugs at my shoulder. “I’ve found another one.”
And so it goes on; Junior’s voice becoming more excited with every find. I can’t keep up. There are so many stalked jellyfish that Junior is finding three in the time it takes me to take a photo of one. They’re everywhere. As I’m taking the photos I keep finding yet more.
Now, I don’t like the cold. I may have mentioned that before? My hands, in particular, don’t cope well with being plunged into icy water or drying in an easterly wind. By the time Junior has racked up 26 stalked jellies and I’ve found a further 15, the pain in my fingers is becoming all-consuming.
Fortunately, by this time, the boys are more than ready to go to the pub for lunch.
“Have people actually looked for stalked jellyfish here before?” Junior asks as we head for the car.
“Yes, I think so,” I say.
“So it really is a proper world record?” he asks.
“Yes, I suppose so.”
Junior glances around him and narrows his eyes at a dog walker.
“What’s up?” I say.
“I don’t want lots of publicity. Do you think the newspapers and TV will find me? I’m not going to tell them where the stalked jellyfish are.”
I assure him that only people who care as much as we do about nature will ever read my blog.
He thinks about it for a moment and nods.
Tomorrow I’ll be off to the rock pools again, on the north coast this time, and I’ll be taking a day off from stalked jellyfish!
February is an amazing time in the Cornish rock pools. Spring is coming and all sorts of fish, sea slugs and other creatures are moving onto the shore. Rock pooling is free, fun and exciting for all ages, so why not wrap up warm this half-term and head for the beach?
There are some great low tides on Saturday 11th, Sunday 12th and Monday 13th February around lunch time. Check the tide times for your local area before you go.
Aim to start one to two hours before low tide as it’s safest to rock pool on an outgoing tide. Keep an eye out for the tide and always stay away from surging waves.
Joining a guided event is the very best way to discover marine wildlife. Experts (including me!) will be on hand to help you find and identify the crabs, fish, shells, starfish and more. At the end of the session you’ll be able to meet everyone’s best finds in the ‘Shore Laboratory’ and find out how the animals live and how to conserve them.
(If anyone know of any other rock pooling events on this half-term, please let me know and I’ll list them here).
Any beach with some sheltered rockpools will do. There are lots all around Cornwall – some of my favourites can be found under the beaches tab at the top of this page.
What to do…
The shore can be very exposed, so make sure you’re well wrapped up and waterproofed. Your feet will get wet so wellies are essential.
Otherwise, all you need is a tub and/or bucket (please don’t use nets as these harm delicate animals). A camera and species guide are useful.
Head for the lower shore (keeping a safe distance from the sea’s edge) and go slowly, looking in shaded, wet areas like pools.
Under rocks and seaweed are great places to look, but move them gently and always return them to how you found them.