If my blog posts have seemed a bit thin on the ground the last few months, it’s fair to put the blame on Atiyah, Brendan, Ciara and Dennis.
Even on the good days the lighting and conditions have been less than ideal so, to make the best of a mediocre tide, I enlisted the help of Other Half. Together, we could look under the sort of rock I usually see but leave alone, knowing it weighs far more than I do.
This short video shows you some of the animals living there…. read on to find out more.
Other Half was pleased with the strawberry anemones, which were enormously plump with all their tentacles retracted.
Under a carefully constructed shelter made of small stones and pieces of kelp we could also see the purple-tipped spines of a green shore urchin. Among its many disc-topped tube feet, a long polychaete worm was exploring.
What drew my eye most, though, were the holes in the rock. These were scattered across the surface of the rock and about the circumference of a pencil. I caught the tiniest glimpse of movement as I looked into one of them.
If I were the BBC Natural History Unit, I’d have filmed inside with an endoscope or transported the rock to deeper water so I could photograph the gaping shells emerging to feed. Instead, you will have to take my word for it that there were piddocks in those holes!
Piddocks are bivalve molluscs (clam shells), which burrow into the rock and spend their entire lives in their holes.
A rock with this many cracks and holes in it is bound to contain some good hiding places for other animals and also some air pockets, which enable some of our most unlikely rock pool wildlife to survive being submerged twice a day. Some insects and other arthropods that breathe air live here, but you have to be patient to see them.
I settled down with my camera and before long, the first waggling antennae of a springtail poked over the rim.
I often see rafts of blue-grey Anurida maritima springtails floating on the surface tension of pools in the summer, but these were smaller still and so pale they looked almost transparent. They are clearly visible in the video but I could only take very blurred still photos.
The fabulous Essential Guide to Rock Pooling by Steve Trewhella and Julie Hatcher was my first port of call in trying to identify them. The book has great photos and plenty of clear information on what to look for. Steve kindly identified these springtails as Axelsonia littorlis – a new species to me. It’s amazing what you find when you stop to look.
The best shots I could get were of a larger bug called Aepophilus bonnairei, a beetle-like creature with red eyes and a spiky coat of hairs around its back and legs. These hairs trap air bubbles, which help the insect to breathe when it is submerged.
Time was short as the tide was already turning and the waves were pounding in. I tried to photograph as many species as I could so that I could put records together afterwards. Some, like the painted top shells and the various crabs, are easy to identify.
One of the most striking sponges I see on the shore is the vivid blue Terpios gelatinosus. Many other sponges are harder to identify confidently.
It seemed that no part of this valuable habitat was left unoccupied. To avoid any of these creatures coming to harm, we gently manoeuvred the rock back in place well before the surging waves reached us.
As always, I was left in utter awe of the fragile little creatures we saw.
It is remarkable that these animals will cling onto life here no matter how much the wind howls and the sea roars around them, while we head home to bring the plant pots in out of the wind, check the fences and put the kettle on.
Though there is much to love about December, I know I’m not the only one who’s flagging well before the end of the month. The spring tides arrive at the perfect time to boost my energy levels, ready for all the rockpooling and writing adventures that await me in 2020.
No-one in the family is sure what day it is, and the gloomy weather isn’t doing anything for our timekeeping. By the time we reach Plaidy, we only have half an hour left before it will begin to get dark. Fortunately, that’s plenty of time to find some winter colour.
This beach is ideal for strawberry anemones, a species that seems to like some wave energy. While I try to take photos of a stunning open anemone, its bright tentacles tucked too far under a dark overhang for my camera to capture well, the waves surge in behind me, finding a hole somewhere in my left welly.
Undeterred by the steady seep of chilly water down my ankle, I take a close look at the tough seaweeds that have clung on at the edges of the pools through the winter storms. There are tufty pink fringes of coral weed, the frayed remains of last summer’s kelp, and, sprouting from the rocks at the pool’s entrance, there are dark clusters of wiry-looking Irish moss. Among these seaweeds are dozens of mauve stalked jellyfish dancing like fairy lights.
In every rocky crack and crevice alongside the pools there are crabs lurking, waiting for the returning tide. A velvet swimming crab watches me through red eyes like glowing coals.
Nearby, the sculpted pink spire of a painted top-shell brightens up a shady overhang that is also home to several cushion stars and bright sponges.
Everywhere I look there are colourful sea squirts, shells, fish and seaweeds. These may be the darkest days of the year, and I can feel a cold coming on, but the brightness of the shore always reminds me that spring is around the corner.
In fact, new life is beginning already in the rock pools. Before I leave I come across this 2mm long baby sea hare grazing on the seaweed. By the summer, if it survives, this tiny slug will have developed a striking brown leopard-spot colouration and will have grown large enough to fill my palm. Perhaps we will meet again?
Happy New Year! May 2020 bring you health, happiness, and many, many beach adventures.
Happy New Year from Bernard the hermit! (Pagurus bernhardus).
The clocks have gone back, endless bands of rain are pushing in from the grey sea and the UK government has announced there will be a general election during the festive season. It might be easier to hide under a duvet and attempt hibernation, but Junior and I have other plans. We grab a camera each and race to the rock pools in search of brightness and sparkle.
Millendreath beach near Looe is cold enough to warrant silly winter hats – mine has big ear flaps and Junior’s is a Christmas pudding – we don’t care what we look like as long as we’re comfortable. We head out onto a rocky outcrop that gives us some shelter from the north-easterly winds and begin our search. When I find a spiny starfish twice the size of my hand in the first pool we come to, we know it’s going to be a good day.
Moving towards the sea, the gullies are full of leathery kelp and Junior knows just what to look for. The iridescent blue dashed lines on the shells of blue-rayed limpets are his favourite thing to photograph and at this time of year, some of the kelp is studded with these miniature jewels.
While Junior gets to work trying to capture these colours, I edge along the slippery rocks towards a tall overhang. Sponges and sea squirts coat the rocks in a huge range of hues from pinks and yellows to blues and greens. Among them are cowries, which feed on the sea squirts. One has abseiled down from the rock and is hanging by its mucous thread.
Nearby, a common starfish is trying to hide in a crevice but its bright orange colour gives it away. In the dark behind it, a Xantho hydrophilus crab is doing a better job of blending in.
For some reason the painted top shells here are paler than on those on our other local beaches and some are almost white. Another feature of this beach is the high population of sea cucumbers. We spot both the sea gherkin and the brown sea cucumber, but they are closed up today, hiding their frilly tentacles.
Just before we move out of this isolated gully, Junior shouts in delight. He has taken his best ever photo of a blue-rayed limpet. All the practice and patience has paid off.
As the tide turns we take a quick look for stalked jellyfish. At this time of year, the seaweed is dying back making it easier to spot them, but the rushing currents from the stormy sea and the large amount of sediment that has been stirred up by the waves aren’t aiding our search. There are probably scores of stalked jellies here as the location is perfect for them, but we only see half a dozen. Among them are three different species: Calvadosia cruxmenlitensis,Haliclystus octoradiatus and a rather sorry-looking closed up specimen of Calvadosia campanulata.
Junior spends a happy half hour watching the cracking cliffs of sand that have formed around the edges of the rain-swollen stream, until the incoming tide begins to send waves up the river, flooding the sand around us and forcing us back.
The first spots of drizzle spatter down and will soon be followed by yet more heavy rain. There’s nothing we can do to prevent the arrival of even shorter days or colder weather, but whenever we need to find colour and inspiration during the dark winter, we will know where to find it.
Happy rock pooling!
Huge thanks to everyone who has shared their finds and photos with me. I love hearing about your rock pooling adventures through my contact page.
With our bingo cards of southerly species part-filled after an exciting day on the south coast, our visitors from Wales still had quite a wish list left to accomplish. To find cup corals and Celtic sea slugs, a trip to a more exposed coast would be needed. Naturally, I suggested my favourite beach: Porth Mear.
The weather was on our side, taking a break between the endless storms that have characterised the summer holidays. So, with swimmers and beach shoes at the ready, we walked down a valley alive with tortoiseshell butterflies to where the bluest sky met the bluest sea. Even the pools at the top of the beach churned with trapped young mullet, scurrying shore crabs and bright anemones. While one of our friends stayed looking at the upper shore pools and gathering shells, Junior and I led our other friend on a long slip and slide across the rocks to reach our goal.
With two hours to go until low tide, we could safely allow ourselves a few distractions on the way. I couldn’t resist stopping to take photos of this wonderful Montagu’s blenny, which let me creep ever closer with my camera as it sheltered under a limpet shell. Blennies are able to move their eyes independently and this one kept an eye on me while scanning the surface of the pool with the other.
My friend was delighted. Although it hadn’t appeared on our bingo card, the Montagu’s blenny is another southerly species which he had never seen in North Wales. This was too easy!
We had met some St Piran’s hermit crabs at Hannafore the previous day, but the colony here was well worth a look too. We found scores of these crabs in and around the pools along a couple of rocky overhangs, living in a range of sizes of shell. This species is doing well here, towards the northerly limit of its known range.
The painted top shells on this beach are always especially pink and beautiful, perhaps because in this more exposed location, they tend to accumulate less silt and micro-algae on their shells. We stopped to take plenty of photos.
Although it can be hard to find stalked jellyfish in the summer when the beach is thick with the seaweeds they attach to, we were determined to tick one or two off the list, especially Haliclystus octoradiatus. This may not be a particularly southerly species, but it occurs frequently around Cornish coasts. After much searching we found a very small blob that was probably a juvenile, but I could only confirm that by looking at photos afterwards.
As the tide dropped further, we picked up our pace and clambered towards a wave-battered gully. This area is only accessible on the lowest tides and, even then, is often out-of-bounds due to the huge swells that pound these rocks for much of the year. Today, the calm conditions were perfect and we could explore in relative safety while keeping an eye on the time.
Junior made straight for the high rocks, where he quickly found the first Celtic sea slug, out in the open among the barnacles and mussels.
These strange black lumps always remind me of armoured cars. This is mainly a very southerly species which is found widely around exposed Cornish coasts, but it has been recorded as far north as the Farne Islands and Scotland.
Celtic sea slugs may not be the most classically pretty slugs, but they are incredible animals. They are able to survive on these rough shores in terrifying conditions and they don’t even have gills. They breathe air and hide away in cracks in the rock when the tide comes in, staying alive by keeping an air pocket sealed inside their bodies and breathing through their skin when needed.
If there is one Celtic sea slug, there is usually a whole colony and we found dozens more on the rocks all along the gully.
Our next stop was a deep overhang with a pool at its base where we knew we would be able tick off another species from our bingo card, the scarlet and gold cup coral.
We had to kneel and lie at strange angles on rocks encrusted with sharp barnacles, but we were soon rewarded with the brilliant glow of many corals.
These tiny orange and yellow corals open their transluscent tentacles in the water here and always astound me. Their delicate soft bodies encase a spongy, fragile exoskeleton, none of which looks like it could stand up to a gust of wind, let alone the fierce, pounding seas that rage through this gully on a daily basis. Despite their soft appearance, scarlet and gold cup corals, like the Celtic sea slugs, thrive in these wild places.
It was a good thing we had left ourselves plenty of time to explore this rock pooler’s paradise. Between deep pools packed with enormous snakelocks anemones and prawns as big as my hand, we scrambled and stared at the huge diversity of species in front of us. Arctic and three-spot cowries moved across the damp surfaces encrusted with pink seaweeds and colourful sea squirts. Groups of light-bulb sea squirts seemed to shine out from the dark water and so much life abounded on every surface that we moved with great caution for fear of accidentally treading on creatures.
The underside of a large boulder at the head of the gully was coated in a red sponge. A quick inspection revealed a small white coil of sea slug sponge. It took me longer to find the slug, which matched its background flawlessly. Rostanga rubra are a common find on these sponges but this was another first for my friend who is almost as obsessed with slugs as I am. He was so delighted with this little find that he took some persuading to move away from the gully before the tide turned.
On our way out of the gully, we waded through a pool, up to our waists in the water and no longer caring how wet we were. Hidden at the back of the pool we discovered a deep hole in the rock that harboured dozens of scarlet and gold cup corals and many large snakelocks anemones. I spotted a leg sticking out from underneath this one and uncovered this Leach’s spider crab (Inachus phalangium) sheltering there.
A shallow pool nearby was dotted with tufts of rainbow weed. To our surprise, these harboured many Asterina phylactica – a small species of starfish. A nearby clump of codium seaweed was also home to several Elysia viridis sea slugs.
On our way back across the beach, my friend found a clump of seaweed with half a dozen stalked jellyfish growing on it. This time, the blobs of the primary tentacles between the arms were easy to spot and we could be sure that these were Haliclystus octoradiatus.
With most of our bingo card of southerly species complete and with another day of rock pooling to try to find the remaining species, my friend set off up the beach to rest and enjoy a well-earned picnic.
Junior and I lingered in the sunny pools, exploring further into the slippery masses of thong weed and kelp until the tide turned.
To celebrate the rare August sunshine, we finished the day with a visit to the vast rock pool where I used to swim as a child. Plunging into the cool waters, I experienced the familiar feelings of wonder and trepidation at the thought of what might lurk in the depths.
We splashed and floated between the rocky walls, finding starfish, prawns, star ascidians and sponges as we swam, side by side. Time might move on, but this beach never loses its magic.
It’s always wonderful to spend time with other rock pooling obsessives, so I was popping with excitement at the prospect of three whole days one the shore with friends from North Wales.
Welsh coasts are wonderfully rich in marine life, but I was looking forward to showing my friends some species that I see in Cornwall which aren’t found in most of the rest of the British Isles. I also had a new camera to try out. We wasted no time in drawing up a bingo card of what we hoped to find.
On day 1 we explored the shore at Hannafore in Looe. Junior knew exactly where to look to cross off the first species on our bingo card: the St Piran’s hermit crab (Clibanarius erythropus). He scrambled over rocks on the mid-shore to a pool where these crabs tend to congregate and within a minute he had located the first one.
Sometimes these hermit crabs, with their red antennae and equal-sized claws are barely visible, hiding deep in their borrowed shells. Today they were less shy. This one seemed to almost fall out of its shell as it investigated my camera, while another nipped boldly at my friend’s fingers as he photographed the crab’s distinctive black and white chequerboard eyes.
As we followed the tide further down the shore, we looked for sea slugs in some of the usual places but with no luck. I soon realised that I was the only one feeling disappointed. With his head hidden from sight under an overhang, one of my friends was gasping in delight at the sight of a painted top shell. They might be common on the shore here, but apparently that’s not the case in Anglesey.
Despite the keen breeze that was preventing the tide running out as much as I’d hoped, we soon ticked off another item from the wish list.
I’ll admit that I hadn’t realised that rainbow wrack (Cystoseira tamariscifolia) is mainly a south westerly species. This bushy seaweed is one of our most unmistakeable plants and is a common sight all around Cornwall. In the water its fronds display a turquoise-green iridescent sheen that is arrestingly beautiful. Out of the water, rainbow wrack loses its magic, appearing brown or dull-green. For some reason I find it impossible to fully capture the colours in photos.
Catsharks favour rainbow wrack when they come inshore to lay their distinctive egg cases often known as “mermaid’s purses”. Despite my hopes of ticking off the egg cases of the greater spotted catshark (Scyliorhinus stellaris) on day 1, the breezy conditions meant we struggled to see into the water. The only eggcases I found were from the smaller species (Scyliorhinus canicula).
The small patch of seagrass that appeared last year was looking denser and wider than before. The length and width of the fronds suggested that it might be Dwarf seagrass (Zostera noltii), a different species from the other seagrass bed I know of on the site.
We embarked on the usual fruitless look for seahorses, which like to live in or near seagrass. I know they’re unlikely to turn up on the shore, but it never stops me looking.
With two species of stalked jellyfish on our bingo card, I was feeling confident of finding them. Instead I kept finding a species that my visitors had already seen, Calvadosia campanulata. These lovely bell-shaped jellies often have brilliant turquoise spots on the bell and and are very photogenic.
Despite the less-than-perfect conditions, we had ticked off some new species and amassed a huge collection of photos by the time the tide turned. With two days still to go and better weather on the way, we were off to an excellent start.
The tide has turned and I am reluctantly preparing to leave one of best rock pooling beaches in Cornwall after a fabulous few hours in perfect conditions in the company of great friends. As you’d expect, the day has been full of interesting finds, from sponge-covered spider crabs to golden clutches of clingfish eggs. My camera batteries are running low and my hair is dripping with seawater from all the time I’ve spent poking my head under seaweed-festooned overhangs. The kids migrated up the beach a while back to investigate the picnic bag but us adults can’t bear to leave the pools. As the water creeps up my wellies, I gently turn one last rock, and then another for luck.
I let out gasp so loud that it would make most people think I’d just broken a bone, but my friend knows better. She moves closer to ask what I’ve discovered, but I’m so overwhelmed with excitement that I can only babble about having, “finally found one”.
I point a trembling finger at the rock. “It’s a Disco…a Discodoris planata,” I stutter, before launching into a garbled explanation of how it used to be a Discodoris has been renamed Geitodoris, but I use Discodoris because I love that name and…
I take a few photos of the cause of my breathless wonder, straighten up and fling my arms over my head and shout at the top of my lungs to attract the children’s attention. It takes me a minute to realise that the distant child I have in my sights is not mine, but Junior has noticed my flailing and comes scrambling across the rocks with his friends.
We crowd in the fast-filling pool and peer down at my rock. Even Junior is a bit confused by my excitement over the small, brown lump I’m indicating.
“It’s Discodoris,” I explain, breathlessly. Instantly, he joins my paroxysms of delight, shrieking out the great news to his friends and going through the same Geitodoris speech as me, for this unassuming slug has become something of a legend in our household.
This isn’t the first time I’ve ever seen one, but it’s the first time I’ve had a working camera with me and it’s the first “Discodoris” that Junior has seen. He is especially impressed with the white star patches on the slug’s back. These are glands which secrete a powerful acid, ideal for seeing off predators.
On close inspection, there’s a pale-yellow blob alongside our “Discodoris” (Geitodoris planata): another slug. At first, I assume from its colour that it must be a Jorunna tomentosa, a slug I often see on this shore. Indeed, there is another Jorunna tomentosa on the same rock. However, this one seems to be getting very cosy with Discodoris. In fact, it looks to me as though they are mating. The yellow slug also has a far flatter profile than any Jorunna tomentosa I’ve seen before.
If the tide wasn’t coming in, and if I wasn’t called away by someone further up the beach finding a giant goby, I might have been able to check the slug’s underside. If I’d done that I could have seen without doubt that this was a second “Discodoris”, a two-for-one package. The underside of Geitodoris planata is fringed in brown spots, unlike the very similar sea lemon, which is all one colour.
Fortunately, social media now enables geeks like me to swap photos with other slug-loving types and sure enough, Geitodoris planata, though usually brown with distinct white acid glands, can sometimes be pale.
Although I will record the slug as Geitodoris planata and there are important scientific reasons for the name change, this little animal will always conjure up glitter balls and platform shoes in my mind. To take photos of the fabled Discodoris, and a mating pair at that, has to be the perfect end to a perfect day.
“The slug formerly known as Discodoris” and a host of other rock pool creatures feature in my book Rock Pool: Extraordinary Encounters Between the Tides. Out now online and in book shops nationwide from September Publishing. If only I’d found one in time to include a photo in the book…
Before I’ve found the time to upload all of last year’s records, the rock pooling event season is upon me again. Junior comes along to help at my first Wildlife Watch event of the year for Cornwall Wildlife Trust at Readymoney Cove, undeterred by the bone-chilling wind.
A crowd of hardy young rock poolers, kitted out from head to toe in weatherproof gear, is gathered at the top of the beach and I am joined by Liz, a lovely volunteer assistant. Half the group have their hands up before I’ve even asked a question and these keen kids are practically bursting with stories and facts about crabs, blennies, pipefish and killer jellyfish. They also have high expectations of what we might find – seahorses and cuttlefish are among the requests – but most of all they want to see starfish.
Starfish of some sort are almost guaranteed on all our local beaches, especially cushion stars, which like to hide under rocks and overhangs. If we are lucky we might also find brittle stars, that walk on their five feathery arms, or even a gargantuan spiny starfish, so I am hopeful that we will be successful on our mission.
As the group spreads across the shore, the finds soon rush in. We turn shiny top shells in our fingers, hold chunky-clawed Xantho hydrophilus crabs, and to the immense joy of one young seahorse enthusiast, we find the next best thing to a seahorse: a male worm pipefish with eggs on his belly.
Pipefish are close relatives of the seahorse and the male takes care of the female’s eggs, storing them in a special groove on his belly until they hatch. Coincidentally this pipefish has taken up residence next to an old pipe.
It only takes a minute for the children to discover a common starfish. I often find one or two on this beach, even though they’re not so common intertidally as offshore. The deep-water harbour alongside this beach is probably packed with them and sometimes young common starfish make their way into these sheltered pools. Today, however, there is something unusual going on.
Under the first stone I turn, I see two baby common starfish. As I look I notice a third, a fourth and then a fifth. On the side of the rock, there is yet another starfish. The adjacent rock has four more.
Everywhere on the beach, children are shrieking with excitement as they find more starfish. There are scores of them among the rocks I look at.
We could easily collect the starfish by the bucket-load, but these children know not to disturb the animals. We keep just a few for our trays so that we can watch them and all those who want to can have a go at holding a starfish before they are returned to their rocky homes.
While the children are caught up in the magic of starfish, I take a moment to explore the rocks at the sea’s edge and discover this wonderful yellow clubbed sea slug, Limacia clavigera.
There is never enough time to take many photos at these events as I am too caught up in the excitement of identifying finds and helping the children learn more about them. We also have plenty of discussions about the animals’ impressive defences and quirky eating habits.
The children do a perfect job of looking after the animals, returning them all safe and unharmed to their homes before the incoming tide floods back into the pools. Despite the chilly conditions, the kids are buzzing with happiness at finding so many starfish. A friend tells me her kids talked of nothing else all the way home.
Even Junior, who has seen most things before, is delighted with today’s finds and even more delighted when he secures the very last cheese and onion pasty from the beach shop for his lunch.
Did you know that starfish can regrow their limbs? Find out more about the secrets of these iconic rock pool animals in my book Rock Pool: Extraordinary Encounters Between the Tides out on 2nd May with September Publishing and available through local and national bookshops and online.
For everyone who loves Cornwall's rock pools. Information about great beaches, marine wildlife and conservation.