Tag Archives: nature

Birthday Rock Pooling

It’s that time of year again. Amazing spring tides, ideal conditions and, of course, it coincides with Other Half’s birthday. Lucky him! What else could he possibly want to do but come rock pooling? To be fair, he needs no persuading that it beats a day in the office and, as a birthday treat, I offer him an evening out afterwards – watching me give a talk at the Cornwall Marine Recorders’ event in Gwithian (with a bar and nibbles).

We pile into the car ridiculously early in the morning to make sure we make it to Prisk Cove in time to meet our lovely friends and their twins to explore as the tide rolls out.

This beach is a little off the beaten track, but worth the walk. We find it empty of people and the tide so far out that the kelp hangs limply in shallow pockets of water in the bay.

The beach’s sheltered position between the Helford and Falmouth Bay, combined with the huge numbers of loose boulders, makes this habitat perfect for many marine species. Despite his initial certainty that he won’t find anything, Junior’s friend is first to find a spiny starfish. Its long tapering arms set with thick spines have an attractive purple hue.

Spiny starfish at Prisk Cove near Falmouth
Spiny starfish at Prisk Cove near Falmouth

We watch its many tentacle feet reaching out to explore the rocks.

Spiny starfish arm in action
Spiny starfish arm in action

The asymmetric heads of flat fish always intrigue me, so I am delighted when we find the first little topknot, then more and more of them. Some are sticking to the rocks, even clinging on when completely upside down, using their fringing fins to mould themselves to bumps and imperfections in the surface. Their mottled patterns can make them hard to spot and they stay completely still to avoid detection.

Topknot flatfish resting on a rock
Topknot flatfish resting on a rock
Flatfish like this topknot have their mouth set on one side of their head.
Flatfish like this topknot have their mouth set on one side of their head.

Under a large rock we find a large edible crab that makes the other twin shriek. She soon overcomes her nerves when I move it out of the way so that we can look at the fish, which are also sheltering here.

Everyone crowds round to see the stunning colours and impressive headgear of the tompot blenny, and the kids are amazed by the smoothness of the rockling’s eel-like skin.

Tompot blenny
Tompot blenny

Other Half holds the edible crab for a quick birthday photo before we pop everything back where we found it.

Edible crab at Prisk Cove
Edible crab at Prisk Cove

Out among the furthest accessible rocks, the twins’ mum is not being outdone. She brings some fish over to show me, among them a beautiful goldsinny wrasse. It’s not a fish I often see on the shore, but it is easily identified by its two dark spots, one at the front of its dorsal fin and the other at the top of its tail.

Goldsinny wrasse at Prisk Cove
Goldsinny wrasse at Prisk Cove

It has wide orange eyes with a flash of blue and the wonderful pouting lips of the wrasse family.

Goldsinny wrasse - a beautifully coloured fish
Goldsinny wrasse – a beautifully coloured fish

The finds flood in and I struggle to keep up with taking photos of everything to ensure that I can submit records afterwards. On one area of the shore I find a large patch of Wakame.

This invasive non-native seaweed is easily identified by its corrugated-looking stipe and thin, floppy fronds. Originating from China, Japan and Korea, it has spread widely in Europe and can out-compete native seaweeds.

White painted top shells, an improbably hairy purse sponge and an interesting anemone all catch my eye before the tide turns.

An especialy hairy purse sponge - presumably just a variant of Sycon ciliatum
An especialy hairy purse sponge – presumably just a variant of Sycon ciliatum
Painted top shells are usually pink, but this beach had many of the white variety
Painted top shells are usually pink, but this beach had many of the white variety

I also discover half a dozen shark eggcases of the Greater spotted catshark (Scyliorhinus stellaris) attached to the rainbow wrack of the lower shore pools.

Catshark egg case among the seaweed
Catshark egg case among the seaweed
When it is in the water, Rainbow wrack is wonderfully iridescent
When it is in the water, Rainbow wrack is wonderfully iridescent

All too soon it seems, the tide is flowing in. At first it is a faint current, but it turns quickly into a churning river through the tight gullies and we retreat to enjoy a birthday picnic.

A lovely little Lamellaria snail, likely Lamellaria latens
A lovely little Lamellaria snail, likely Lamellaria latens
Limacia clavigera sea slug at Prisk Cove
Limacia clavigera sea slug at Prisk Cove
An especially small anemone growing on rainbow wrack.
An especially small anemone growing on rainbow wrack.

Spooky Rock Pool Spells

Cornish Rock Pools Junior loves Harry Potter. A while back he noticed that a lot of rock pool creatures have scientific names that sound like spells straight from a Hogwarts classroom.

Rock pool animals have many amazing (and disgusting) tricks up their sleeves. Some are simply fearsome looking like the Devil crab in the photo above. Others have weapons and disguises.

What better way to learn their names than by chanting them spell-style to unleash their freaky abilities?

So, wands at the ready – swish and flick – here are some top spooky rock pool spells.

Sepia officinalis – Invisibility spell

A cuttlefish shows off its camouflage skills in the IFREMER visitor centre, Concarneau, Brittany.
A cuttlefish shows off its camouflage skills in the IFREMER visitor centre, Concarneau, Brittany.

Nothing can hide better than a Common cuttlefish. Sepia officianalis can change colour and texture in an instant to make it invisible to both its predators and its prey.

Marthasterias glacialis – Regrow-an-arm spell

This Spiny starfish (Marthasterias glacialis) is regrowing two of its arms.
This Spiny starfish (Marthasterias glacialis) is regrowing two of its arms.

Many sea creatures like crabs and starfish can re-grow a lost limb. Starfish like this Spiny starfish can regenerate several arms at once, so it’s not uncommon to find one with just a couple of arms and three stumps.

Here’s a spooky story for you… Some say that fishermen in the North Sea used to hack starfish in half when they found them in their nets. Starfish attacked their catch so they were determined to get rid of them. They slaughtered all the starfish they could get their hands on, certain they were reducing the population. Instead, each half of the severed starfish began to regenerate, slowly regrowing its arms. So, every time the fishermen cut one in half, they created two starfish. Soon the area was swarming with starfish.

I’m not convinced this story’s true, but it makes a great Halloween tale!

Berthella plumula – Acid squirting spell

More dangerous than it looks - the Berthella plumula sea slug
More dangerous than it looks – the Berthella plumula sea slug

Lots of sea slugs use poisons from their prey to defend themselves and some produce acid. The Berthella plumula can squirt out sulphuric acid from a special gland when it’s attacked. If you pick one up, it’ll make your skin blister and fall off (so best not to!).

Anemonia viridis – Harpoon stinging spell

The tentacles of the Snakelocks anemone are packed with harpoon-like stinging cells
The tentacles of the Snakelocks anemone are packed with harpoon-like stinging cells

Use this spell to unleash a secret weapon – the nematocysts. All jellyfish, anemones and other related animals have special stinging cells called nematocysts. Inside each cell is a coiled harpoon, which is fired out into anything that touches the tentacles.

Here’s a video of a pool full of Anemonia viridis eating an unfortunate fly.

Lineus longissimus – Smelly slime spell

Part of a Bootlace worm on a rock - if you pick it up you'll get stinky slime on your hands.
A Bootlace worm on a rock – if you pick it up you’ll get stinky slime on your hands.

The bootlace worm is in the Guinness Book of Records as the world’s longest animal. When fully unravelled it often stretches 7 or 8 metres but the longest ever recorded was an incredible 55 metres long. More importantly, though, its special power is giving out a stinky slime. A perfect spell to use against your enemies!

Elysia viridis – Energy-making spell

The photosynthesising sea slug - Elysia viridis, grazing on Codium tomentosum seaweed.
The photosynthesising sea slug – Elysia viridis, grazing on Codium tomentosum seaweed.

Feeling worn out? Try the Elysia viridis spell instead of over-doing the trick-or-treat sweets. This amazing little sea slug retains energy-making chloroplasts from the seaweed it eats. The chloroplasts carry on making food for the slug through photosynthesis, giving the slug an ideal energy boost.

Aplysia punctata – Smoke screen spell

We must have accidentally disturbed a sea hare (Aplysia punctata), making it release a cloud of purple ink.
We must have accidentally disturbed a sea hare (Aplysia punctata), making it release a cloud of purple ink.

Werewolves, zombies and vampires on your tail? Don’t panic – use the smoke screen spell!

Sea hares (Aplysia punctata) may look like dull brown blobs, but they are as strange as rock pool creatures get. Not only do they lay eggs in the form of pink silly-string, but they have the ability to shoot out a cloud of purple ink when attacked, providing a perfect smoke screen.

These are just a few of the bizarre things our rock-pool creatures can do. There’s plenty more rock pool magic to learn.

If you’d like to know more about the gruesome habits of the animals on our shore, have a read of my guide to revolting rockpools. You can also take part in organised events to meet the creatures for yourself. Happy Halloween!

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