The Worlds Within Rock Pools, With Cornwall Wildlife Trust


As part of National Marine Week, on Friday 10th of August we welcomed Cornwall Wildlife Trust marine biologists Niki Clear and Adele Morgan for a special Ecoasteering session at Port Gaverne.

exploring rock pools with marine biologists from Cornwall Wildlife Trust on an Ecoasteering session with Cornish Rock Tors

With a 1.02 metre low tide in the middle of the morning we had a large expanse of intertidal rocks and rock pools uncovered and waiting to be explored.  With Hugo and Toby leading a group of enthusiast of all ages, and accompanied by Niki and Adele, we set off along the south side of Port Gaverne.  The first thing that we found were an abundance of Celtic sea slugs; admittedly they aren’t the most glamorous of marine creatures, but these small mottled grey slugs are quite rare and difficult to find so Niki and Adele were pleased to record a colony here.

exploring rock pools with marine biologists from Cornwall Wildlife Trust on an Ecoasteering session with Cornish Rock Tors

celtic sea slugs

Along the same rock wall we found several different small crabs, including a Montague crab and several small shore crabs.  The Montague crab is a pretty pumped up little fellow with big pincers, and will grab hold of anything that it can and not let go – including in this case a small piece of plastic straw (which we managed to take off him and dispose of).

montague crab holding a piece of plastic straw

With Niki and Adele on hand to spot and identify, we worked our way along the intertidal zone, turning over stones in rock pools and trying to identify all of the creatures that swam and scuttled off into the shadows of the seaweed.  We saw lots of shannies, and of course all of the creatures that can’t move of their own accord such as strawberry and snakelock anemones.  Hugo also found a five-bearded rock ling towards the end of the session.

strawberry anemone

As well as scrambling around the rocks and rock pools, and exploring some of the large caves, the group also explored the gut at low tide, finding lots of beautiful blue-rayed limpets which are about the size of a grain of rice and can be found clinging to kelp fronds.

blue rayed limpets

After a few jumps and a go on the “seaweed slide” – a slippery gulley on a wave-washed ledge, the group explored the exposed rocks all the way back to the beach.

coasteering with cornish rock tors

“It is advisable to look from the tide pool to the stars and then back to the tide pool again.”

John Steinbeck

rainbow wrack

rainbow wrack seaweed

These sessions with experienced marine biologists are really rewarding and very informative, for all members of the group and our guides who also get to enhance their knowledge.  Rock pools and the rocks and ledges that are exposed as the tide goes out are each tiny little worlds within which, over the course of a single tidal cycle, countless dramas are played out by the species that live there.

exploring a sea cave on a coasteering session with cornish rock tors

small crab in a rock pool

We’re hoping to host more Your Shore Beach Rangers sessions in the future, and all being well Cornwall Wildlife Trust’s Shore Search team will be joining us to do a proper survey at Port Gaverne, and officially record some of the amazing marine life that calls our coast home.

rockpooling at port gaverne on a cornish rock tors ecoasteering session