Tag Archives: cornwall

Gem anemone hunt

We weren’t really rock pooling, just going for a walk to the beach, or so we said. Junior packed his hammer and chisel in case there were fossils and I packed my camera, because you never know.

On my last wander at our local beach I had hoped to find some gem anemones to photograph, but didn’t succeed. It was worth another look for these tiny creatures, which have stripy tentacles and bright colours around their mouths when they are open, but at low tide most of them are retracted into white-striped blobs.

When retracted gem anemones look rather like an urchin test with a warty surface and white stripes down their sides.
When retracted ,gem anemones look rather like an urchin test with a warty surface and white stripes down their sides.

I left the sounds of hammering and splitting rocks behind me at the edge of the shore, where Junior was happily amusing himself on a fossil hunt, and headed towards an unseasonably glassy sea, pausing to look for anemones in the small pools on the way.

At the water’s edge, I reached a large pool too deep for gem anemones, but in the middle of the pool a submerged boulder was covered in Irish moss seaweed, providing the perfect habitat for stalked jellyfish. I looked so closely among the tangles of weed, hunting for tiny jellies, that I almost missed the huge stalked jellyfish right under my nose.

Haliclystus octoradiatus stalked jelly near Looe, Cornwall
Haliclystus octoradiatus stalked jelly near Looe, Cornwall

This was an unusually large Haliclystus octoradiatus stalked jellyfish, easily distinguished from the other species we see in Cornwall by the presence of blob-shaped primary tentacles in between its arms.

Most stalked jellyfish of this species have just one primary tentacle blob between each pair of arms, but this one had far more blobs than usual. The jelly can use these primary tentacles as anchors to grip onto the seaweed if it chooses to move, using a looping, cartwheeling motion.

I've sometimes seen a stalked jelly with one extra primary tentacle blob between its arms, but this one had lots of extras.
I’ve sometimes seen a stalked jelly with one extra primary tentacle blob between its arms, but this one had lots of extras.

In another nearby pool I spotted this colourful Calvadosia cruxmelitensis stalked jellyfish, well decorated with white nematocysts, which are its stinging cells.

Calvadosia cruxmelitensis stalked jellyfish
Calvadosia cruxmelitensis stalked jellyfish

Junior joined me at this point, wanting to show me a blenny he’d found. We scrambled nearly to the top of a high rocky outcrop in which some small pools had formed. There was no sign of his little fish, and there were no gem anemones, but there was this daisy anemone.

Daisy anemones have many layered tentacles, like daisy petals and come in all sorts of colours.
Daisy anemones have many layered tentacles, like daisy petals and come in all sorts of colours.

We carried on our expedition through a gap in the rocks to the adjoining beach where clear, shallow pools lined with pink encrusting seaweed nestled under a towering overhang carved out by the sea into the shape of a breaking wave.

Strawberry anemone
Strawberry anemone

These pools were full of anemones too and we stopped to take photos of clusters of snakelocks anemones and a rather flattened-looking strawberry anemone before I noticed the first gem anemone. It was closed up, forming a diminutive pink blob that blended perfectly into the colours of the pool. Close to it was another.

As we moved among the chain of pools we found dozens, but not a single one was open. Junior stared determinedly into every cranny, excited that the pools he had found were proving so interesting.

“There are some open anemones here,” he called out, “maybe Dahlia anemones? What do gem anemones look like when they’re open?”

I knelt on the rock beside him. At the far edge of the pool, tucked under a small ledge, I could see the white stripes of the gem anemone tentacles. Much cheering and hugging ensued.

The open gem anemones Junior found near Looe
The open gem anemones Junior found near Looe

Soon I was able to show Junior my up-close photos of the anemones so he could see why I was so obsessed with finding them. Each one had a vivid, almost fluorescent green mouth tinged with bright pink spots at its corners. The anemone’s mouths were framed in deep red and grey rays that stretched to the base of the zebra striped tentacles, some of which had flashes of green at their bases.

The mouth of the gem anemone
The mouth of the gem anemone

Truly one of our most spectacular anemones, people rarely notice the gem anemone because it is only a few centimetres across even when fully grown.

Gem anemone near Looe, Cornwall
Gem anemone near Looe, Cornwall

Junior is already planning a night time return to these pools to investigate whether these anemones will glow under the light of our ultra-violet torch. Watch this space!

Gem anemone -winter colour in the Cornish rock pools
Gem anemone -winter colour in the Cornish rock pools

Festive Rock Pooling

Tis the season for overspending, overindulgence and over-exhaustion, so what better way to recharge the batteries than some fresh air and rock pool exploration? It’s a family tradition for us this time of year to head in the opposite direction from the shops and to take a breather on the beach.

Christmas cards don’t often depict the traditional Cornish winter weather for good reason. Between the fog and the persistent mizzle, we have to imagine the view through the valley to the beach. Even when we arrive on the shore, we can barely make out the sea, although we can hear it crashing over the rocks and surging up the gullies.

Waves breaking out of the mist at Porth Mear
Waves breaking out of the mist at Porth Mear

The lower shore might be unsafe, but there’s no shortage of colour and variety in the sheltered pools. The rain kindly stops for long enough to let us enjoy our potter through the pools and we have the beach to ourselves.

Other Half finds a large common hermit crab, Pagurus bernhardus, tapping at a shell and we wonder if the crab’s about to move house. Looking closely, the shell it’s interested in is smaller than its own shell and when I look inside there are legs in there. Most likely our hermit is carrying a female around with her until she moults, hoping to mate with her when she does.

Hermit crab holding on to his mate at Porth Mear
Hermit crab holding on to his mate at Porth Mear

The rock pool wildlife couldn’t care less that it’s Christmas, but the bright anemones can’t help but look festive and are all the easier to see now that the seaweeds have died back for the winter.

Snakelocks anemone
Snakelocks anemone
Beadlet anemones at Porth Mear
Beadlet anemones at Porth Mear

Stalked jellyfish are also easier to see on the remaining short crops of Irish moss and red seaweeds in the pools. In a short stretch I find Haliclystus octoradiatus and a beautiful red Calvadosia campanulata stalked jelly.

Haliclystus octoradiatus stalked jellyfish at Porth Mear
Haliclystus octoradiatus stalked jellyfish at Porth Mear
Calvadosia campanulata stalked jelly
Calvadosia campanulata stalked jelly

Another jelly blob catches my eye, just a minute red speck among the seaweed. It seems to be moving, so I focus in with my camera to reveal a baby sea hare grazing its way across a tuft of seaweed. Its red sides seem to be snow-speckled with white and its black-fringed parapodia look like a tiny chimney pot.

Baby sea hare, Aplysia punctata.
Baby sea hare, Aplysia punctata.

In a few months’ time, if it survives the winter, this slug will swell and grow into a fat brown lump many times this size, feeding on the spring growth of seaweed.

Zipping across a shallow pool, a fish smaller than my little finger heads for the shelter of a low rocky ridge where it lies still, relying on its camouflage. The young shanny obligingly sits still for a couple of photos.

A young shanny (Common blenny)
A young shanny (Common blenny)

Soft rain begins to blow into my face as I work my way back over the slippery rocks to rejoin Other Half and Junior, who are entertaining themselves with the noble sport of throwing stones at other stones.

No Christmas stress for us... with the beach to ourselves and an endless supply of stones to throw.
No Christmas stress for us… with the beach to ourselves and an endless supply of stones to throw.

With our wallets intact and our appetites renewed, we’re ready for the feasting to begin.

Wishing you all a very Merry Christmas. Here’s to more rock pooling adventures in 2019!

A Christmas cushion star!
A Christmas cushion star!

 

A summer of snorkels, jellyfish and wrasse

On a summer’s day when the sea and the sky are a matching blue and the whole world sparkles, there’s nothing as inviting as donning a snorkel and taking a swim across the bay. This summer, for the first time, Junior joined me in my forays over the rocky reefs.

While he built up experience, we floated shoulder to shoulder and sculled our way over the waving seaweed to the deeper gullies.

On our third snorkel outing, I was enjoying the sun on my back and the gentle roll of the waves when Junior screamed down his snorkel. I grabbed his arm in case he was hurt, but he was frantically pointing and making the “fish’”sign with his hand. He had just seen his first ballan wrasse.

The fish was a full-sized adult, maybe 40 or 50cm long with a thick body and a criss-cross patterns of lines interspersed with pale blue spots. An impressive fish. Undeterred by Junior’s shriek of excitement, it carried on its slow, hovering path through the kelp-lined gully for a while before darting away as we neared.

Juvenile ballan wrasse can be bright green like this one, but they grow up to around 50cm long when they're mature.
Juvenile ballan wrasse can be bright green like this one, but they grow up to around 50cm long when they’re mature.

On the same venture, we spotted barnacles feeding with their feathery legs, shore crabs strolling along the sea floor, a shanny surveying its territory from the top of a rock and great glistening shoals of sand eels rolling by. On other days, we came across groups of corkwing wrasse with pouting lips and turquoise-striped faces, spider crabs lurching through the kelp, and tangled snakelocks anemones spreading their green tentacles.

Snakelocks anemone
Snakelocks anemone

Nearby, crowds of tourists paddled and swam, oblivious to the beauty below them (or the pinching claws and stinging tentacles near their feet).

This summer has seen waves of jellyfish drifting through, from comb jellies to the harmless moon jelly, the less harmless blue and compass jellies and the enormous barrel jellies. Some days the sea was thick with jellyfish, but this didn’t stop Junior from mastering the art of catching waves on his bodyboard or wiping out headfirst into the blue-jelly-soup. He swam for the shore in a hurry on one of our snorkel safaris though, when a compass jelly brushed over my face and stung my back.

Compass jellies have striking markings and also pack a nettle-like sting
Compass jellies have striking markings and also pack a nettle-like sting

I have almost no photos of our snorkelling expeditions this year. Next year, when Junior is more confident, I’ll be able to carry a camera, but this season we just revelled in the perfect days and soaked up the sun . As we knew it would, the summer ended abruptly, dissipating like a mirage from one day to the next and the water is no longer so inviting.

For now, we are hanging up our snorkels and returning to the rock pools, exchanging beach shoes for wellies as the autumn chill moves in, but there is everything to look forward to. A week of Shoresearch surveys starts tomorrow in Looe, which is guaranteed to bring new finds and lots of species records for Cornwall Wildlife Trust.

The empty beaches make this a wonderful time of year to explore the rock pools and before we know it, the first of the autumn storms will blast in, washing who knows what onto our shores. Watch this space!

Between the snorkel trips, I did squeeze in some rock pooling. Here are some of my favourite photos from the summer.

Xantho hydrophilus crab
Xantho hydrophilus crab
Candy striped flatworm grazing on bryozoans in Looe
Candy striped flatworm grazing on bryozoans in Looe
A variegated scallop with irridescent shining eyes
A variegated scallop with irridescent shining eyes
A green shore urchin with its tentacle feet extended
A green shore urchin with its tentacle feet extended
Doris ocelligera sea slug - I recorded these for the first time a couple of months ago and have found them regularly in the same spot this summer.
Doris ocelligera sea slug – I recorded these for the first time a couple of months ago and have found them regularly in the same spot this summer.
St Piran's hermit crab - now a common find on all our local beaches.
St Piran’s hermit crab – now a common find on all our local beaches.

Summer Holiday Marine and Beach Events in Cornwall

Whether you and the children want to try rock pooling, beach cleans, snorkelling or dolphin watching this summer, you’ll find plenty of fabulous family-friendly events all around Cornwall.

Please check the full details on the organiser’s website, including booking requirements, any charges and age restrictions before attending.

Remember to book well in advance if required.

Have fun!

 

Event Date Time Location Info More details…
Polzeath Rock Pool Ramble 12 July 10.15am – 12.30pm Polzeath BOOKING ESSENTIAL National Trust
Rockpool Expedition and Picnic 14 July 11.30am – 2.00pm Nr Porthcothan BOOKING ESSENTIAL Cornwall Wildlife Trust
Seaweed Search 15 July 12.00 – 2.30pm Prisk Cove, Mawnan Smith Cornwall Wildlife Trust
Durgan Beach Clean 15 July 2.00pm – 4.00pm Bosveal NT Car Park National Trust
Snorkel Safari 15 July 2.00pm – 5.00pm Little Fistral, Newquay CONTACT ORGANISER Newquay Marine Group
Polzeath Rock Pool Ramble 17 July 2.30pm – 4.45pm Polzeath BOOKING ESSENTIAL £2 per person Polzeath Marine Group
Snorkel Safari and Barbecue 17 July 6.00pm – 8.00pm Gyllingvase Beach, Falmouth BOOK TICKETS, Over 9s only. Falmouth Marine Group
Polzeath Beach Clean 18 July 9.30am Polzeath Polzeath Marine Group
Polzeath Marine Crafts 25 July 10.30am – 12.30pm Polzeath Marine Centre £2 per person Polzeath Marine Group
Polzeath Rock Pool Ramble 26 July 10.15am – 12.30pm Polzeath BOOKING ESSENTIAL £2 per person Polzeath Marine Group
Radical Rockpooling 29 July 11.45am – 2.00pm Polzeath BOOKING ESSENTIAL. Over 11s only Cornwall Wildlife Trust
Seaquest Seawatch – watching for dolphins etc. 30 July 11.00am – 1.00pm Lizard Point Cornwall Wildlife Trust
Sunset Session Boat Trip – Wildlife Watching 30 July 6.30pm – 8.30pm Newquay Cornwall Wildife Trust
Seaquest Seawatch – watching for dolphins etc. 31 July 11.00am – 1.00pm St Agnes Head NCI Station Cornwall Wildlife Trust
Polzeath Rock Pool Ramble 31 July 1.15pm – 3.30pm Polzeath BOOKING ESSENTIAL £2 per person Polzeath Marine Group
Paddle for Plastic Kayak Adventure 31 July 2.00pm – 5.00pm Lizard area BOOKING ESSENTIAL. Cornwall residents only. Cornwall Wildlife Trust
Seaquest Seawatch – watching for dolphins etc. 1 Aug 11.00am – 1.00pm Towan Headland, Newquay Cornwall Wildlife Trust
Polzeath Marine Crafts 1 Aug 10.30am – 12.30pm Polzeath Marine Centre £2 per person Polzeath Marine Group
Sandymouth rock pool ramble 1 Aug 1.30pm – 3.00pm Sandymouth  £1 per person. Check booking details with organiser National Trust
Looe Summer Snorkel 1 Aug 4.00pm -6.00pm Hannafore, Looe BOOKING ESSENTIAL. 9-24 year olds only. Cornwall Wildlife Trust
Seaquest Seawatch – watching for dolphins etc. 2 Aug 11.00am – 1.00pm The Rumps, Pentire Headland Cornwall Wildlife Trust
Polzeath Rock Pool Ramble 2 Aug 2.15pm – 4.30pm Polzeath BOOKING ESSENTIAL £2 per person Polzeath Marine Group
Seaquest Seawatch – watching for dolphins etc. 3 Aug 11.00am – 1.00pm Hella Point, Porthgwarra Cornwall Wildlife Trust
Polzeath Beach Clean 3 Aug 9.30am Polzeath Polzeath Marine Group
Rock Pool Explorer 3 Aug 15.00 – 17.00 St Michael’s Mount Check booking requirements with organiser. National Trust
Beach Clean 4 Aug 10.00 – 11.00 Hemmick Beach, Roseland National Trust
Strandline Treasures and Sand Sculpture Competition 4 Aug 1.00pm – 3.00pm Nr Polzeath BOOKING ESSENTIAL Cornwall Wildlife Trust
Seaquest Sunday – watch for dolphins etc 5 Aug 11.00am – 1.00pm Pendennis Head Falmouth Marine Group
Learn to Snorkel in a Rock Pool 6 Aug 3.00pm – 5.00pm Bude BOOKING ESSENTIAL Cornwall Wildlife Trust
Porthcurnick beach clean 6 Aug 10.00am – 11.00am Porthcurnick, Roseland National Trust
Pendower beach clean 6 Aug 2.00pm – 3.30pm Pendower, Roseland National Trust
Marine Litter Masterpieces 7 Aug 10.00am – 12.00 midday Marazion Cornwall Wildlife Trust
Crazy About Crabbing 8 Aug 09.15 – 11.30 Mevagissey Cornwall Wildlife Trust
Polzeath Marine Crafts 8 Aug 10.30am – 12.30pm Polzeath Marine Centre £2 per person Polzeath Marine Group
Seal Squad XP Roadshow Festival 8 Aug and 9 Aug 11.00am – 4.00pm Geevor Tin Mine Included in entry to Geevor Cornwall Wildlife Trust
Polzeath Rock Pool Ramble 9 Aug 9.15am – 11.30 am Polzeath BOOKING ESSENTIAL National Trust
Extreme Rock Pooling 10 Aug 10.00am – 1.00pm Port Isaac BOOKING ESSENTIAL Cornish residents and over 8s only £36 per person Cornwall Wildlife Trust
Rockpool Explorer 10 Aug 10.00am -12.00 midday St Michael’s Mount Check booking requirements with organiser National Trust
Rockpool ramble 10 Aug 10.45am – 12.45am Readymoney Cove, Fowey £1.50 for non-members of Friends of Fowey Estuary Cornwall Wildlife Trust
Night time rock pooling 10 Aug 9.00pm – 11.00pm Gyllingvase, Falmouth BOOKING ESSENTIAL Falmouth Marine Group
Porth Beach Clean 11 Aug 10.00am – 1.00pm Porth, Newquay Newquay Marine Group
Rockpool Ramble 12 Aug 11.30am – 1.30pm Porthlevan BOOKING ESSENTIAL, Over 6s only Cornwall Wildlife Trust
An introduction to the rock pools 12 Aug 11.00am – 1.00pm Hannafore, Looe BOOKING ESSENTIAL Cornwall Wildlife Trust

wildlifewatch@cornwallwildlifetrust.org.uk

National Marine Week Summer Holiday Rockpool Ramble 12 Aug 12.30pm – 2.00pm Hannafore Looe Looe Marine Conservation Group
Polzeath Rock Pool Ramble 12 Aug 11.45am – 2.00pm Polzeath BOOKING ESSENTIAL £2 per person Polzeath Marine Group
Newquay Summer Snorkel 12 Aug 2.00pm – 4.00pm Little Fistral, Newquay Check booking arrangements with organiser. 11+ only Cornwall Wildlife Trust
Polzeath Rock Pool Ramble 14 Aug 1.15pm – 3.30pm Polzeath BOOKING ESSENTIAL £2 per person Polzeath Marine Group
Polzeath Marine Crafts 15 Aug 10.30am – 12.30pm Polzeath Marine Centre £2 per person Polzeath Marine Group
Sandymouth Summer Rock Pool Ramble 15 Aug 1.00pm – 3.00pm Sandymouth  £1 per person. Check details with organiser National Trust
Polzeath Rock Pool Ramble 16 Aug 2.30pm – 4.45pm Polzeath BOOKING ESSENTIAL £2 per person Polzeath Marine Group
Rockpool Explorer 17 Aug 3.00pm – 5.00pm St Michael’s Mount Check booking arrangements with organiser National Trust
Sunset Beach Clean 18 Aug 7.00pm – 8.00pm Harlyn Bay
Rockpool Explorer 17 Aug 3.00pm – 5.00pm St Michael’s Mount Check booking arrangements with organiser National Trust
Fowey Marine Day 21 Aug 10.00am – 2.00pm Town Quay, Fowey Cornwall Wildlife Trust
Summer Sunset Beach Clean 21 Aug 7.00pm -8.00pm Trevone Bay Beach Guardian
Polzeath Marine Crafts 22 Aug 10.30am – 12.30pm Polzeath Marine Centre £2 per person Polzeath Marine Group
Rock Pool Explorer 24 Aug 10.00am – 12.00 midday St Michael’s Mount Check booking arrangements with organiser National Trust
Polzeath Rockpool Ramble 24 Aug 10.15am – 12.30pm Polzeath BOOKING ESSENTIAL National Trust
Polzeath Marine Crafts 29 Aug 10.30am – 12.30pm Polzeath Marine Centre £2 per person Polzeath Marine Group
Summer Rock Pool Ramble at Sandymouth 29 Aug 1.00pm – 3.00pm Sandymouth  £1 per person. Check booking details with organiser National Trust
Rockpool ramble 30 Aug 1.30pm – 3.30pm Nr. Mawnan Smith BOOKING ESSENTIAL Cornwall Wildlife Trust
Polzeath Rock Pool Ramble 31 Aug 1.45pm – 4.00pm Polzeath BOOKING ESSENTIAL £2 per person Polzeath Marine Group
Rockpool Explorer 31 Aug 3.00pm – 5.00pm St Michael’s Mount Check booking arrangements with organiser National Trust
Hemmick beach clean 1 Sep 10.00am – 11.00am Hemmick beach, Roseland National Trust
Seaquest Sunday – Looking for dolphins etc. 2 Sep 11.00am – 1.00pm Pendennis Head, Falmouth Falmouth Marine Group
Porthcurnick beach clean 3 Sep 10.00 – 11.00 Porthcurnick beach, Roseland National Trust
Pendower beach 3 Sep 2.00pm – 3.30pm Pendower beach, Roseland National Trust

If you know of any other summer beach events in Cornwall this summer, let me know and I’ll add them to the list.

Wading through jelly – Comb Jellies  in Looe

I should be at home, cracking on with some work, but I’ve heard there are comb jellies about and I could do with some photos for my jellyfish course for ERCCIS.

Any excuse.

I cut through overgrown vegetation, down the cliff path to a favourite cove. In the ten minutes it’s taken me to walk here, the grey clouds have lifted and the sea’s looking good enough to dive into.

My progress through the rocky gully is slow. The warm weather has brought an explosion of slippery sea lettuce which blocks my view of my feet as they feel for underwater rocks. Tangles of pink spaghetti, the eggs of sea hares, are wrapped around many of the green fronds and a close inspection reveals that dozens of stalked jellyfish (Haliclystus octoradiatus) have already made their homes here.

As I move into deeper water, something catches my eye, floating below the surface. It’s so transparent it’s barely there, but it shimmers intermittently. With some difficulty, the current swishing the jelly back and forth, I scoop it up and carry it in cupped hands to a sheltered overhang. For a moment I think I’ve dropped it, then it swims out.

Barely there - a transparent Beroe cucumis comb jelly in my hand
Barely there – a transparent Beroe cucumis comb jelly in my hand

I’m treated to a fabulous display of iridescence as the comb jelly beats its tiny combs, sending a trail of light and colour up the lines on its tiny body.

Between the current washing into the pool and the jelly’s own surprisingly speedy swimming efforts, it slips away each time I come close to getting it under the camera. To add to the fun, my camera can’t see it. I take a whole series of photos of nothing. The perfect transparency of the animal means I can only focus on the seaweed below.

The Beroe cucumis comb jelly has a characteristic sack shape.
The Beroe cucumis comb jelly has a characteristic sack shape.

When another comb jelly washes into the pool, I’m sure there will be lots more opportunities to attempt photos. Stepping out into the open water, I take some time to accustom my eyes, staring past the surface reflection into the water. Soon, I notice comb jellies everywhere.

The irridescent combs of Beroe cucumis
The irridescent combs of Beroe cucumis

There are dozens, hundreds even, and some are large enough to fill the palm of my hand. Even the large jellies pose a challenge to my camera, but amongst the many seaweed shots, I start to take a few that show off the jellies’ light display.

While most are the large species, Beroe cucumis, with their characteristic sack shape, there are a few smaller ones amongst them. These are sea gooseberries, Pleurobrachia pileus. They are barely a couple of centimetres long, spherical, with two trailing tentacles.

A sea gooseberry with trailing tentacles. Its combs are arranged in lines up its sides.
A sea gooseberry with trailing tentacles. Its combs are arranged in lines up its sides.

Despite their tiny size, they are just as mesmerising as the B. Cucumis, the lines down their sides flickering every colour of the rainbow.

Sparkles of irridescence from a passing Sea gooseberry
Sparkles of irridescence from a passing Sea gooseberry

Among all the comb jellies I spot an even smaller interloper, a hydroid medusa. Hydroids are related to jellyfish, but their adult form usually lives attached to seaweeds, stones or shells. This minute creature is a baby hydroid, looking very much like a jellyfish as it actively swims past, beating its bell fringed with short tentacles.

Hydroid medusa - probably Clytia hemisphaerica swimming by
Hydroid medusa – probably Clytia hemisphaerica swimming by

The pattern of the cross on top of it and the fringe of dark spots around the edge of the bell suggest that it is a young Clytia hemispherica.

Hydroid medusa showing its delicate pattern and short tentacles.
Hydroid medusa showing its delicate pattern and short tentacles.

The glare of sunlight on my screen combined with the transparency of all the animals I’m trying to photograph make it impossible to tell how I am doing. I give up taking photos and simply enjoy the spectacle until the tide calls time and forces me back up the beach.

Comb jellies are supposed to phosphoresce, which would be amazing to see. I’m wondering if I can sneak in a little night time rockpooling this weekend. Although the jellies are here in huge numbers today, they may disappear as quickly as they arrived. I should be working, but some things are just too exciting.

A Night Out in the Rock Pools

Nights out tend to become a distant memory when you’re a parent. For the most part I don’t miss them. I have, however, been looking forward to Junior being old enough to join me for night time rock pooling. Towards the end of last year, we tried it for the first time and, although the conditions weren’t ideal, he’s been asking to go again ever since.

The best low tides always happen around the middle of the day, and the middle of the night, but we compromise for this first family expedition of the year, choosing a reasonable low tide at around 10.30pm. The warm, calm weather provides good opportunities for seeing nocturnal activity and tonight I’m trying out my ultraviolet (UV) torch.

It doesn’t disappoint.

Head torch at the ready - night time rock pooling is a perfect adventure
Head torch at the ready – night time rock pooling is a perfect adventure

I’ve always known that certain species glow under UV light, but I had no idea how much. We’ve barely taken ten paces out across the rocks when we see our first snakelocks anemone, shining from the darkness like an eerie green beacon. The colour is wonderfully alien.

Snakelocks anemone at night under UV light - a true alien of the Cornish rock pools
Snakelocks anemone at night under UV light – a true alien of the Cornish rock pools

This fluorescence is caused by certain proteins within the animals that take in light of one colour and emit it as another. Some deeper water species can use these properties to appear red, even though red light is filtered out as it passes through the water, meaning the only light available to underwater creatures is UV or blue.

It’s not clear why snakelocks anemones and other sea creatures might want to fluoresce in this way. It seems there may be some benefit in it for their symbiotic algae or it might give them sun protection. It may just be a by-product of a protein that’s useful in other ways. Whatever the reasons, it produces an incredible glow. Junior is already talking of coming back at Halloween.

A spooky night time rock pooling walk is definitely on the programme for this Halloweeen!
A spooky night-time rock pooling walk is definitely on the programme for this Halloweeen!

It’s not just the anemones that take our breath away. If you’re used to rock pooling in daylight when most animals are hiding away under rocks and seaweed, the sheer level of activity in after dark takes you by surprise.

A scratching, crackling sound stops us in our tracks. It’s coming from the rocks. I lift the seaweed to show Junior a group of limpets. Some are feeding, their strong radulas scouring seaweed off the rock and chipping bits of rock. Others are setting into their home scars, grinding their shells into their grooves to create a perfect fit. Close-up, their activities make a surprising amount of noise.

Limpets on their way home as the tide retreats
Limpets on their way home as the tide retreats

Most rockpool animals are largely nocturnal. Pools that seem empty in daytime become bustling cities of activity. We watch hermit crabs milling around in large numbers, crabs marauding through the pool and across the rocks, fish floating in plain sight. Prawns come towards the light and watch us before shooting away backwards.

A green shore crab looking blue in the UV light
A green shore crab looking blue in the UV light
Hermit crabs are more active at night, every pool is teeming with them
Hermit crabs are more active at night, every pool is teeming with them

Other Half spots a small species of spider crab (Macropodia sp.) decorated with long fronds of seaweed edging sideways across the pool. It’s moving too fast to take a clear photo in the poor light. The blurring makes it look even more alien.

A blurry small spider crab (Macropodia sp) moving across sand.
A blurry small spider crab (Macropodia sp) moving across sand.

A scorpion fish lies still on the sand, watching out for prey.

A scorpion fish (Taurus bubalis) hiding in plain sight.
A scorpion fish (Taurus bubalis) hiding in plain sight.

One surprise is the stunning colours of the seaweeds under the UV light. Some of the dark red seaweeds take on a far more intense, bright colour, glowing red, pink and orange. Where the top shells have worn spires, their tips glow pink.

A grey topshell on a red seaweed under UV light
A grey topshell on a red seaweed under UV light

After an hour, tiredness and cold begin to set in. We switch off our torches and take a moment to gaze at the stars before we head home to bed. Junior is already asking if we can come again the next night, and the next.

It looks like I’ll be having a few more nights out this summer.

Cornish Rock Pools on Countryfile

When the BBC approached me about filming a Countryfile episode with Matt Baker on the signs of spring, I reeled off all the exciting things we might find in the Cornish rock pools. By mid-April there would be male pipefish with eggs on their bellies, scorpion fish babies already hatched, crabs with egg masses under their tails and so much more. No problem.

Worm pipefish are related to seahorses - it is the male that broods the eggs along a special groove on his underside.
Worm pipefish are related to seahorses – it is the male that broods the eggs along a special groove on his underside.

What I hadn’t considered was that the TV crew’s packed schedule would require us to film on an exposed north coast beach on small tide. All I could do was to hope for good weather and some luck.

The West Cornwall episode of Countryfile is available on BBC iPlayer here. (Available at the time of writing).

Portreath, near Redruth, has wide, golden sands and magical craggy cliffs. Like many other beaches in Cornwall, it has a fantastic community group working to conserve wildlife and keep it clean – Love Portreath.

To the east of the bay lies what used to be an important mining port, sheltered by a long harbour wall with a stretch of rocks alongside.

Portreath in the drizzle as the tide drops
Portreath in the drizzle as the tide drops

The pools here are a great habitat, but the fierce waves sweep any small stones away, leaving only large boulders and deep overhangs as hiding places for the rock pool creatures. Great for wildlife, but tricky for rock poolers, especially with a strong swell rolling in.

Fortunately, I had help in the form of Cornish Rock Pools Junior and two of his friends, Ashley and Rowen. Without their keen eyes and amazing patience, it would have been an impossible task to find as much as we did in just fifteen minutes.  Louis led Matt Baker crashing surf, assuring him there would be more to find on the lower shore, while Ashley plunged waist-deep into pools trying to catch a goby. Rowen spotted a cushion star at the back of a crevice in the rock. Needless to say I was prepared to risk getting my hand stuck to retrieve it (and nearly did).

Matt Baker and the kids at Portreath
Matt Baker and the kids at Portreath

In just a few minutes we managed to assemble a good collection of common rock pool creatures: a green shore crab, a common blenny, some top shells and, of course, the cushion starfish.

Everyone loves starfish, but now the nation knows that cushion stars and their relatives have some gruesome eating habits. Go me!
Everyone loves starfish, but now the nation knows that cushion stars and their relatives have some gruesome eating habits. Go me!

Inevitably, I made my television debut by telling the nation that starfish feed by pushing their stomachs out of their mouths and dissolving their prey. You’re welcome!

The common blenny (or shanny) is perfectly adapted to shore life and can even breathe through its skin when out of the water. It also has a great smile.
The common blenny (or shanny) is perfectly adapted to shore life and can even breathe through its skin when out of the water. It also has a great smile.

Although we failed to find many signs of spring other than the large amounts of seaweed sprouting all around us, the magic of television went to work and the final programme included some fabulous footage of green shore crab eggs hatching out into the plankton.

Female crabs keep their eggs underneath their tails until they hatch out.
Female crabs keep their eggs underneath their tails until they hatch out.

It’s incredible how all the snippets we filmed on the day were woven together into the final programme. Huge thanks go to the all of the Countryfile crew for putting us at ease and doing their TV magic, and to Matt Baker in particular for taking the time to chat and take photos with the children.

Even though conditions weren’t ideal, it was a wonderful opportunity to showcase the Cornish beaches and the creatures that survive in this extreme environment.

Junior getting his radio microphone pack installed - his least favourite part!
Junior getting his radio microphone pack installed – his least favourite part!