But there is more on the shore than just watery rockpools to explore. Plants and animals live in all sorts of different places. Some cling to rock and boulders, others tuck themselves tightly into crevices, or hide beneath rock and boulders, and often they grow on other plants and animals too. Smaller seaweeds like gut-weed often grow on limpets , giving the impression of a full head of green hair’, whilst tiny blue-rayed limpets live on kelp.
The rocky shore is a harsh place to live. It is a constantly changing environment. When the shore is exposed to the air, temperature levels and salt concentrations rise and fall. In the summer, rock pools warm up, seaweed dries out and evaporation causes salt concentrations to climb dramatically. In winter, the cold air can cause ice crystals to form on plants and animals, and fresh water from rain and run off can dilute the sea water until pools become merely brackish.
As the tide turns and starts to flow back in covering the shore it is often a welcome relief for both plants and animals, but sometimes this in itself can cause problems. Pounding waves can dislodge or damage creatures, so many have had to develop special mechanisms to hold on, like the aptly named kelp ‘holdfast’ or the Cornish clingfish’s strong sucker that is formed through adapting its pelvic fins.
With all this going on it is a wonder anything can survive on the shore at all – but even in such a harsh environment some species survive in abundance. All the plants and animals that live on the shore have special ways of coping or ‘adaptations’ to help them survive and even flourish in what can sometimes be a very stressful place to live.
At low tide the shore is an excellent place to get close to marine creatures in their natural habitat and to discover the amazing plants and animals that can live in such a challenging environment. The number of different plant and animals species increases the closer you get to the low tide mark. This is because plants and animals that live here have to spend less time out of the water so more can manage to survive. Fewer species are hardy enough to withstand being out of the water for long enough to live at the top of the shore so there are less of them here. Often people will walk straight past many of these upper shore species, such as barnacles (a member of the same family as crabs). Whilst they are sometimes perceived as being boring, these upper shore species are some of the most ingenious creatures on the shore and are able to survive extreme environmental changes.
On Lundy the best place to go rockpooling are in Devil's Kitchen and the Landing beach, where there are hundreds of different seaweeds and marine creatures occupying every nook and cranny. Limpets and barnacles dominate the very upper levels of the shore where seaweed species like channelled wrack and knotted wrack can survive.
At mid to lower shore level other species become more common. Lundy has lots of crab species including the green shore crab, the edible crab and the velvet swimming crab, all of which can be found sheltering under rocks and boulders. Lucky explorers may come across the occasional spiny squat lobster clinging upside down against the underside of rocks. Starfish species like the cushionstar, spiny starfish and seven-armed starfish are common and can be found on the undersides of overhanging rocks and jammed into rock crevices. Really keen observers can find the rare scarlet and gold star corals or brightly coloured star ascidians tucked away under overhangs in damp shady locations.
In rockpools fish like the shanny and tompot blenny can be seen darting for the cover of seaweed as you approach. Looking under rocks can uncover an array of different creatures as well as crabs. Fish like the shanny can survive out of water, sheltering from the elements amongst damp seaweed and under rocks where they won’t dehydrate. The worm pipefish is related to the seahorse, its size and coloration make it very difficult to spot as it is perfectly camouflaged amongst the brown seaweeds. Rocklings and clingfish are often seen.
There is always something to discover on a rocky shore from snails with trap doors and bright orange starfish with seven arms to colour changing cuttlefish - it is impossible to tell what a rockpool ramble might uncover.
Throughout the summer it is possible to join a Lundy warden on a rockpool ramble or to explore by yourself. Check the tide times in the Tavern or ask a warden for advice, but remember always abide by the Code of Conduct.