All-Weather Rock Pooling

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.

Junior's training in rockpooling in all weathers started early - out with Countryfile age 3
Junior’s training in rockpooling in all weathers started early – out with Countryfile age 3

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.

Entwined worm pipefish couple, Looe.
Entwined worm pipefish couple, Looe.

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’.

Out of the water, stalked jellyfish just look like blobs. Calvadosia cruxmelitensis, Looe
Out of the water stalked jellyfish just look like blobs. Calvadosia cruxmelitensis, Looe

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.

A handsome Xantho incisus crab, Looe
A handsome Xantho incisus crab, Looe
A green shore urchin half-hidden by the shells, seaweeds and pebbles among its spines, Looe
A green shore urchin half-hidden by the shells, seaweeds and pebbles among its spines, Looe

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.

Limacia clavigeira, the orange-clubbed sea slug. In the water its vivid rhinophores and markings are stunning.
Limacia clavigeira, the orange-clubbed sea slug. In the water its vivid rhinophores and markings are stunning.

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.

Arctic cowrie, Looe
Arctic cowrie, Looe

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.

A small species of 'decorator' spider crab
A small species of ‘decorator’ spider crab

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.

I don’t know where he gets it from…

It's not a proper day out if there's no water on the lens!
Like mother, like son… It’s not a proper day out if there’s no water on the lens!

A Window to the Underwater World

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.

A baby sea hare, Aplysia punctata, grazing on seaweed.
A baby sea hare, Aplysia punctata, grazing on seaweed.

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.

The striking colours of the Scarlet and gold cup coral.
The striking colours of the Scarlet and gold cup coral.

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.

Abundant Scarlet and gold cup corals line the overhanging rocks
Abundant Scarlet and gold cup corals line the overhanging rocks

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.

The Goniodoris nodosa sea slug shows its frills once in the water
The Goniodoris nodosa sea slug shows its frills.

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.

Bob the lobster in the rock pool, Cornwall
Bob the lobster in his/her rock pool, Cornwall

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!

The Stalked Jellyfish World Record (for Portwrinkle)

“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.

Cornish Rock Pools Junior searches for stalked jellyfish at Portwrinkle
Cornish Rock Pools Junior searches for stalked jellyfish at Portwrinkle

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.

An adult Haliclystus ocroradiatus with a baby next to it. This species is a recognised feature of the Looe and Whitsand Marine Conservation Zone.
An adult Haliclystus ocroradiatus with a baby next to it. This species is a recognised feature of the Looe and Whitsand 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.

The first find is a Haliclystus octoradiatus - the 'blob' (primary tentacle) between each pair of tentacle arms helps identify this species.
The first find is a Haliclystus octoradiatus – the ‘blob’ (primary tentacle) between each pair of tentacle arms helps identify this species.

“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.

One of Junior's many, many finds. A Calvadosia cruxmelitensis stalked jelly. The white spots (which are stinging cells) trace the outline of the tentacle arms and form a 'Maltese cross'.
One of Junior’s many, many finds. A Calvadosia cruxmelitensis stalked jelly. The white spots (which are stinging cells) trace the outline of the tentacle arms and form a ‘Maltese cross’.

Seconds later, while I’m crouching to photograph his find, he tugs at my shoulder. “I’ve found another one.”

Junior finds another species, the Calvadosia campanulata, which gets its name from its bell-like shape.
Junior finds another species, the Calvadosia campanulata, which gets its name from its bell-like shape.

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.

Two different species living together, Calvadosia cruxmelitensis (left) and Haliclystus octoradiatus (right)
Two different species living together, Calvadosia cruxmelitensis (left) and Haliclystus octoradiatus (right) at Portwrinkle

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.

Despite the cold, I sneak in a few photos of other species. This is a baby sea hare (Aplysia punctata).
Despite the cold, I sneak in a few photos of other species. This is a baby sea hare (Aplysia punctata).
Decorator crab (Macropodia sp.)
Other Half found this fantastic Decorator crab (Macropodia sp.)
Painted top shell at Portwrinkle
Painted top shell at Portwrinkle

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!

Junior and Senior doing our thing at Portwrinkle
Junior and Senior doing our thing at Portwrinkle

February Half Term Rock Pooling in Cornwall

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?

When?

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.

Join a Guided Event

Looe Marine Conservation Group will be running a free rockpooling event at Hannafore Beach, West Looe, on Wednesday 15th February at 13.30. All welcome!

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).

Cornish Rock Pools - spider crab at Looe rockpool ramble
Cornish Rock Pools – spider crab at Looe rockpool ramble

Where?

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.

Read my guide to rockpooling to discover how to find lots of amazing creatures and keep them and you safe. You can also find out how to pick up a crab.

What you might find…

Even in the depths of winter the rock pools are full of life. In February spring is just round the corner and lots of animals will be moving in for the breeding season.

Expect to see crabs, fish, anemones, sea snails, prawns, starfish and perhaps even a sea slug – these little creatures come in an amazing variety of shapes and colours.

Facelina annulicornis- a rather lovely sea slug
Facelina annulicornis- a rather lovely sea slug

To help you identify your finds, I’ve produced guides to crabs, fish, starfish and shells.

If you need help identifying something, take a photo if possible and get in touch through my contact page, Facebook or Twitter. I love seeing your finds.

Happy Half-Term Rockpooling!

Strawberry anemones on a partly submerged rock
Strawberry anemones on a partly submerged rock

 

 

 

 

Port Nadler in the Fog

The other side of the Looe valley has disappeared. Beneath the thick Cornish sea fog, a steady, soaking drizzle is blowing in. Junior, contemplating the scene out of our back window, decides it’s a perfect day to go for a picnic at Port Nadler.

Two and a half miles later, with water running off our noses and mud splashed up our waterproof trousers, we arrive in the deserted bay. We listen to the whistles of oystercatchers, sounding closer than they are in the fog. Junior follows trails of bird footprints across the beach.

The sun doesn’t shine on our picnic, but the rain eases and we begin to catch glimpses of the sea through the mist. After a quick sandwich, we start exploring.

The cool, damp conditions aren’t great for humans, but they’re ideal for rockpool creatures that need to avoid drying out. I’ve barely taken a few steps across the rocks when I spot a decorator crab out for a walk among the seaweed. It’s so well covered with pieces of weed that I have to move it to take a distinguishable photo.

A decorator crab - a small species of spider crab - out for a walk
A decorator crab – a small species of spider crab – out for a walk

It’s not a particularly big tide, but it’s low enough to access some wide, shallow pools and an area strewn with loose rocks begging to be turned.

Cornish clingfish wriggle under every stone and sucker on to their hiding places. It won’t be very long now before they start laying their golden egg clusters under these rocks. 

A Cornish clingfish uses its sucker to grip the rock
A Cornish clingfish uses its sucker to grip the rock

Overhangs in the rock harbour extensive colonies of sponges. These Sycon ciliatum sponges catch my eye.

Sycon ciliatum sponges
Sycon ciliatum sponges

We find a large and very red shore urchin under a rock, waving its tentacles in the water. I show Junior the purple tips to the spines. 

Shore urchin at Port Nadler
Shore urchin at Port Nadler
Shore urchin - its capped, mushroom-like tentacles protrude from among the spines
Shore urchin – its capped, mushroom-like tentacles protrude from among the spines

Nearby, a Lamellaria perspicua is inching along the rock. It looks like a slug, but is actually a snail, with an internal shell that you can’t see when it’s alive. Its back looks like an abstract splash-painting of white, purple and yellow. These markings help it to blend in among the sea squirts it likes to eat.

Lamellaria perspicua - a slug-like snail
Lamellaria perspicua – a slug-like snail
Lamellaria perspicua at Port Nadler
Lamellaria perspicua at Port Nadler

A few minutes later, Junior spots a yellow blob on a rock. This time it’s a true sea slug, a Berthella plumula (or ‘Feathered Bertha’ as I call them). I pop it in the water and soon we can see its rhinophores (antennae) emerging. The dark spot in the centre of the slug is an internal shell.

Berthella plumula sea slug (Feathered Bertha)
Berthella plumula sea slug (Feathered Bertha)

We find what might be the first stalked jellyfish record in this location, a Calvadosia cruxmelitensis. Another one to add to the Looe and Whitsand Bay Marine Conservation Zone records.

Calvadosia cruxmelitensis - possible a first record for Port Nadler
Calvadosia cruxmelitensis – possible a first record for Port Nadler

I spot this lovely little keyhole limpet under a rock. As the name suggests, they have a hole in the top of their shells.

Diodora graeca - The keyhole limpet
Diodora graeca – The keyhole limpet

The odd-looking Candelabrum cocksii is abundant here, although it’s not common in the UK as it prefers warmer waters. A relative of the jellyfish, this hydroid (hydrozoan family) can contract and expand greatly, so varies in size and appearance. The white balls are the stinging cells, although fortunately they’re not harmful to humans. These creatures have a very limited range in the UK.

Candelabrum cocksii - one of the strangest Cornish rock pool inhabitants
Candelabrum cocksii – one of the strangest Cornish rock pool inhabitants

It’s a productive afternoon. We find more crabs than we can count and plenty of cushion stars and brittle stars too.

Junior spends some quality time with a cushion star
Junior spends some quality time with a cushion star

 

A small dahlia anemone with some lovely shells stuck to its column
A small dahlia anemone with some lovely shells stuck to its column
This Xantho incisus crab doesn't look too pleased to meet us!
This Xantho incisus crab doesn’t look too pleased to meet us!
Brittle star
Brittle star

This time of year, it might not seem appealing to trudge through the mud and rain to reach secluded bays, but it’s worth the effort.

When the tide rolls in and the oystercatchers gather on the rocks, we begin the long climb out of the bay and strike out for home.

A Shell Collecting Bonanza on Looe Beach

After a week of ear-numbing northerlies, the low January sunshine is at last winning through. Junior sets to work with his bucket and spade, attempting to create a sand fort that can be seen from space while I take a stroll at the water’s edge.

Looe Beach - a herring gull is also checking out the pile of shells at the water's edge
Looe Beach – a herring gull is also checking out the pile of shells at the water’s edge

The stretch of sand that forms Looe beach is ideal for summer holidaymakers to lounge on, but generally offers little to the rockpooler, unlike the surrounding shores. Today is different; probably due to a combination of large tides and strong winds from an unusual direction.

Glistening mounds of shells are heaped the length of the shore, and are being nudged onwards by the incoming tide. They crack under my feet despite my efforts not to trample them. 

Shells on Looe beach
Shells on Looe beach

It’s not unusual to see the odd limpet or a few mussel shells here – the harbour is carpeted with them – but this haul of shells is not just large, it’s more diverse than usual. There’s such a kaleidoscope of blues, whites, oranges and pinks that I have to get in close to focus on individual shells.

Shell colours and patterns - a carpet shell (above) and scallop (below)
Shell colours and patterns – a carpet shell (above) and scallop (below)

Among the shells, emerald-green strips of sea grass glow in the sunlight.

Sea grass in the January sunlight at Looe beach.
Sea grass in the January sunlight at Looe beach.

Many of the shells are fresh, some still alive, while others are worn down to their mother-of-pearl lining. I throw the live ones back into the water although it’s probably too late.

A Grey topshell worn down to the mother-of-pearl layer
A Grey topshell worn down to the mother-of-pearl layer
A sea-worn turban top shell (recognisable by the crinkled, 'jelly-mould' shape to the upper face of the shell.
A sea-worn turban top shell (recognisable by the crinkled, ‘jelly-mould’ shape to the upper face of the shell.

Most of these shells are molluscs, either sea snails (gastropods) or clam shells (bivalaves), but among them lies a remarkably intact sea potato. These fragile urchins come from the echinoderm (‘spiny skin’) family and are related to starfish and sea cucumbers. When alive, sea potatoes are covered in bristly spines and live in muddy-sand burrow. These spines quickly rub off if the animal is washed out of its home. What’s left is this white potato-shaped shell.

Sea potato (urchin) on Looe beach
Sea potato (urchin) on Looe beach

I’m soon absorbed, staring into the mass of shells. There’s nothing particularly rare here, but I never could resist shell collecting.

A tiny cowrie shell - Looe beach.
A tiny cowrie shell – Looe beach.

I’m especially pleased with the cowrie and the Auger shell (easily recognised by its twisting tower shape).

Auger shell (Turritella communis) on Looe beach
Auger shell (Turritella communis) on Looe beach

Before long the tide’s rolling in and Junior wants my help to fortify his sand constructions against the waves. As the sun retreats over western side of the valley, the January chill returns and we walk home in the evening glow. Below the cliffs I can still hear the sound of the waves pushing shells up the beach.

Razor shells burrow in the muddy sand near Looe beach.
Razor shells burrow in the muddy sand near Looe beach.
This thick-lipped dog whelk was still alive so I put it back in the sea for a second chance.
This thick-lipped dog whelk was still alive so I put it back in the sea for a second chance.
Time to go home.... A fishing boat returning to Looe harbour as the sun sets behind West Looe Hill.
Time to go home…. A fishing boat returning to Looe harbour as the sun sets behind West Looe Hill.

 

50 Years on from the Torrey Canyon – A fragile recovery

Next month, 50 years will have passed since the Torrey Canyon tanker ran aground off the Isles of Scilly, releasing a 700 square km oil slick. On the last day of 2016, I visited Porth Mear to learn how a long-term survey has revealed the secrets of the beach’s fragile recovery, and to see if the St Piran’s hermit crab (Clibanarius erythropus)has managed to make more than a temporary comeback.

Clibanarius erythropus - A red legged hermit crab making a comeback in the Cornish rock pools this year.
Clibanarius erythropus – A red legged hermit crab making a comeback in the Cornish rock pools this year.

When the Torrey Canyon hit rocks in February 1967, its cargo of oil ended up on the Cornish, Breton and nearby coasts. The oil, along with huge quantities of solvent emulsifying chemicals used in an attempt to disperse it, decimated seabird populations and marine wildlife.

Concerned by the impact on his local beach, biology teacher, Richard Pearce, decided to monitor the wildlife on the shore three times a year. He’s been doing his survey without fail ever since.

I wasn’t born when Richard first marked out his quadrats on Porth Mear beach, but I grew up hearing stories of the horror people felt at the sight of the thick black tide, the pervasive smell of the oil, and the woefully unprepared volunteers attempting to shift the cloying oil with garden tools. Decades later, lumps of tar were still washing onto our beaches after every storm.

I’ve always wondered what the process of recovery looked like, so I jumped at the chance to join Richard at Porth Mear for survey number 150.

Survey 150…

It’s clear, after many surveys, that Richard knows the beach well. So well, in fact, that even when the gouged crosses and splodges of green paint that mark the survey quadrats have worn away or been covered up by seaweed, he still knows exactly where they are.

Richard examines a quadrat while Chris notes the data
Richard examines a quadrat while Chris notes the data

As he shows me his method, calling out the presence and coverage of seaweeds, barnacles and molluscs to his partner, Richard tells me how after the Torrey Canyon disaster the green seaweeds were the first to flourish. With many of the grazing molluscs wiped out by the oil and the chemicals used to disperse it, the seaweeds soon took over. After this other animals gradually returned.

Crosses in the rock and paint marks show the quadrat boundaries - now on his 150th survey Richard knows just where they all are!
Crosses in the rock and paint marks show the quadrat boundaries – now on his 150th survey Richard knows just where they all are!

Over the years, Richard has seen many changes. Some are seasonal or weather related, others are harder to explain but may be due to warming seas. Why one pool that was once crammed with mussels now has almost none and why limpets are doing particularly well this season is hard to say, but the data he is collecting reveals changes that would otherwise go unnoticed.

 

Not for the faint-hearted - Richard has to scrabble down steep rocks and wade knee-deep to reach some of his quadrats.
Not for the faint-hearted – Richard has to scrabble down steep rocks and wade knee-deep to reach some of his quadrats.

The tide drops and, while Richard is knee-deep examining a quadrat alongside a long deep pool, I explore the lower shore pools, determined to find out whether the St Piran’s crab is still here. After an absence of more than 30 years, this equal-clawed hermit crab started to reappear around Cornwall in 2016 and we had one record on this beach in the spring. Although past records are too patchy to be sure, it’s thought that pollution from the Torrey Canyon played a role in the loss of this species, so 50 years on it would be lovely to find it re-establishing.

Every time I see a shell move, I leap on it, looking for the red legs and spotty eyes, but every one is a common hermit crab (Pagurus bernhardus).

The disappointment mounts... I find lots of common hermit crabs (Pagurus bernhardus) - the right claw is much chunkier than the left with lots of raised bumps on it.
The disappointment mounts… I find lots of common hermit crabs (Pagurus bernhardus) – the right claw is much chunkier than the left with lots of raised bumps on top.

Rooting around in the pools always reveals some unexpected treasures. I make my first record of a stalked jellyfish (Calvadosia cruxmelitensis) at this site.

Stalked jellyfish - Calvadosia cruxmelitensis - at Porth Mear
Stalked jellyfish – Calvadosia cruxmelitensis – at Porth Mear

This is always a good beach for finding Cornish clingfish, and the rocks of the lower shores don’t disappoint. In one small area I find a dozen of these stunning little duck-faced fish, some with iridescent blue spots on their heads.

Cornish clingfish at Porth Mear
Cornish clingfish at Porth Mear

 

And another Cornish clingfish...
And another Cornish clingfish…

As I follow a gully across the shore I find several scorpion fish lurking among the rocks. Brittle stars lurch away into the seaweed and Xantho pilipes crabs close up, pretending to be pebbles.

My other half and Junior join me, hunting for crabs and fish. Every thirty seconds I remind them that we need to look for little hermit crabs and they ignore me as they should. They’re used to me and my missions.

Not a hermit crab... a feisty male edible crab at Porth Mear.
Not a hermit crab… a feisty male edible crab at Porth Mear.

Junior at least keeps pointing out suitable pools. He knows they like the ones with pink coralline seaweed and there are lots here. I barely have time to glance at one before he’s trying to drag me to the next.

And then it happens. A shell moves and as soon as I pick it up I know. The legs are red, the shape’s wrong for the common hermit crab.  When the crab extends its claws there can be no doubt, they’re hairy and pretty much equal sized. This is a St Piran’s crab.

When I see the red legs and equal-sized claws I know - a St Piran's hermit crab at Porth Mear
When I see the red legs and equal-sized claws I know – a St Piran’s hermit crab at Porth Mear

I yell like I’ve won a golden ticket. Under my camera it’s easy to see the black and white spotty eyes of the crab. We all gather to look and as I take an underwater photo, I see other shells moving.

The long eye-stalks with black and white-spotted eyes are distinctive too - a St Piran's crab at Porth Mear
The long eye-stalks with black and white-spotted eyes are distinctive too – a St Piran’s crab at Porth Mear

Sure enough, this next shell has a St Piran’s crab in it, and the next, and the next. While I’m taking photos in the pool, Richard is examining shells on the rock by a small overhang. “There are nine more here,” he says. Soon we’ve counted at least fourteen. They’re all larger than the one found here earlier in 2016.

A St Piran's hermit crab in the pool at Porth Mear
A St Piran’s hermit crab in the pool at Porth Mear

Whether there are other groups of St Piran’s crabs on this beach is hard to say. The tide is surging in now so we’ve run out of time to search.

A St Piran's crab foraging in the pool at Porth Mear
A St Piran’s crab foraging in the pool at Porth Mear

The existence of the St Piran’s crab is a fragile one; storms, temperature change, pollution and disturbance threaten our shore wildlife now more than ever. Richard’s survey provides an incredible conservation tool with its wealth of data about what’s here and how it changes.

50 years on from the Torrey Canyon disaster, the confirmation of the St Piran’s crab’s comeback is an uplifting way to complete this survey (and the year).

A Scorpion fish at Porth Mear
A Scorpion fish at Porth Mear
A rock goby
A rock goby
A brittle star on the move at Porth Mear.
A brittle star on the move at Porth Mear.
Xantho pilipes crab pretending to be a pebble at Porth Mear
Xantho pilipes crab pretending to be a pebble at Porth Mear
As the last tide of 2016 rushed in, I had to say aurevoir to this little St Piran's hermit crab. Hopefully they'll be sticking around in 2017.
As the last tide of 2016 rushed in, I had to say au revoir to this little St Piran’s hermit crab. Hopefully they’ll be sticking around in 2017. Happy New Year!

 

 

For everyone who loves Cornwall's rock pools. Information about great beaches, marine wildlife and conservation.