Rockpools… Cornwall’s other world
Battered by waves, exposed to the sun, rockpools are tough environments to live in. And yet each one is home to a multitude of wonderful creatures. Twice a day, as the tide recedes, we get a chance to explore them, to spot the fish, shellfish, seaweeds and other lifeforms that live in between the tides.
Here are some of the more unusual inhabitants…
The beadlet anemones ‘flower’ in the rockpools, but when they find themselves out of the water on low tides they close up and all you will see is a red jelly like blob. Once the tide comes in, or if they are in a deep rockpool, their short tentacles emerge to sting and catch passing preys like small crabs, shrimp and small fish.
With the long, wavy, bright green and purple tipped tentacles that give them their name, snakelock anemones are usually found in the sunniest part of the rockpool. Unlike the beadlet, their tentacles do not disappear when out of water, but just lie limp against the rocks. Be careful, they sting!
Look out for the tiny porcelain crab under rocks and boulders in shallow pools. They're not only small, but also flat and hairy, so they are camouflaged well amongst the silt and weed. They are fragile creatures and will shed a leg if attacked, hence their name!
Another crab that you may see if very lucky is the St Piran Hermit Crab. They are much shyer than the common hermit crab and will often disappear inside their shell at the first sight of danger. Unlike other hermit crabs, their claws are equally sized and are red and electric blue. It’s only in the last few years that these tiny crabs have returned to Cornwall’s coast.
Sea Slugs come in all shapes and colours and are far more beautiful than their land based namesakes. There are over 100 species in the seas around the UK and some of them are amongst the most colourful animals on the planet. They feed on seaweeds, sponges, anemones and other sea slugs. When rockpooling you might be lucky to find one hiding amongst the seaweed.
Looking a bit like an armoured woodlice, Chitons are a type of crawling mollusc, a bit like a Limpet, but long and flat rather than round and pointy. They are usually found stuck on a rock, feeding on algae using their tough rasping tongue, the world's strongest biological structure!
The cushion starfish grows up to 5cm wide with usually five very short, broad arms. It has a puffy appearance, hence the name and is often found in rockpools, lurking in the seaweed or under rocks. All cushion starfish are born male but when they increase beyond a certain size, some of them develop into females.
The weird and the wonderful, all to be found on a beach near you… for more info on these creatures click here.
Our friends at Falmouth’s Rock Pool Project gave us this advice…
Rock pooling is a very cheap summer activity. You don't need a lot of special equipment and you may well already have everything you need. Coastal rocks can be sharp or they can be slippery, so thick soles with good grips are recommended. Wellies are perfect, and old trainers are good too but make sure to rinse the salt off of them afterwards. Prepare for the Great British weather, a.k.a. anything can happen. It's also a good idea to keep a change of clothes handy, in case you get even closer to the rock pool life than you intended.
A good field guide will greatly enhance your rock pooling experience. There are many UK guides available, and some good options include:
Collins Complete Guide to British Coastal Wildlife
Seasearch Guide to Seaweeds of Britain and Ireland
RSPB Handbook of the Seashore
Rock Pool: Extraordinary Encounters Between the Tides: This book by local Cornish author Heather Buttivant gives you a more in depth (sorry) knowledge of the creatures who inhabit the pools around the Cornish coast. Check out Heather's award-winning rock pooling website here.