What are shingle ridges and how do they form?
A vegetated shingle habitat is a pile of small shingle stones, colonised by plants along the coast.
It forms along a high energy coastline where the waves are strong enough to fill the beach with pebbles. During storms these pebbles are deposited past the high tide mark forming a ridge. As this ridge is only disturbed during storms, it is left undisturbed for long periods of time giving vegetation a chance to grow and colonise it.
The shingle ridge is a section 7 priority habitat, meaning it has principal importance for biodiversity conservation. It’s vulnerable habitat that needs protection to safeguard it and the biodiversity it supports.
Shingle ridges are important because they are generally very exposed, with little soil or freshwater, so the plants that live here have to adapt to survive. This habitat is also home to a variety of important coastal birds such as ringed plovers.
On the shore you can find barnacles, limpets and dog whelks. These animals are resilient molluscs with hard calcium carbonate shells that keep them safe against strong waves. They also have a muscular foot which is a strong and sticky flat section of the body that helps keep it secure. Ever tried to remove a limpet from a rock with just your hands? Difficult isn’t it! It’s so strong that 1cm2 of muscle is more powerful than one of our hands. Some rock dwelling molluscs such as piddocks are even strong enough to burrow into solid rock.
Our spotter sheet might help you identify a few seashore wildlife species.
Along the high shore you will find the shingle verge where you can spot some of our rare and protected plants. These include sea kale, yellow-horned poppy, sea beet, sea pea, sea spurge, and sea radish. These speciescan only survivehere because they have adapted. For example, sea kale has incredibly long roots that grow up to 2 metres deep. Sea campion has closely packed waxy leaves to reduce their surface area and protect it from the strong winds.
Shingle spotter sheet (PDF - 7,709KB)
Surprisingly, shingle beaches are also used as breeding grounds by some birds, such as ringed plovers which sometimes successfully nest at Pensarn. This is because they can lay their eggs amongst the pebbles. Once hatched, their chicks are well camouflaged and they can feed in the finer sand close to the water. The ringed plover is at risk - populations are declining, they are vulnerable to habitat loss and nests easily fail because of disturbance by walkers, dogs or predating gulls.
You can find more information on the ringed plover on the North Wales Wildlife trust website.
The lapwing can also be occasionally spotted at Pensarn. The lapwing is a black and white bird found on wetlands and coastal areas. It is recognised by its distinctive ‘peewit’ sounding calls. The lapwing has suffered significant decline in recent years and has now been placed on the red list for birds. You can find more information on the lapwing on the North Wales Wildlife Trust website.
Out to sea
Out to sea you may occasionally see marine mammals such as harbour porpoise, grey seal, and bottlenose or common dolphin.
Learn more about the marine mammals around the North Wales coastline from the North Wales Wildlife Trust.