Maritime Cliff and Slope

Sea cliffs are formed at the junction between land and sea where a break in slope is formed by slippage and / or erosion by the sea. Slopes can vary from 15 degrees to vertical. Most of the cliffs along the coast of NW England are soft cliffs composed of boulder clay. However around Morecambe Bay there are stretches of Carboniferous limestone cliff and St Bees Head is composed of sandstone, as are the cliffs of Hilbre Island. Small sections of gritstone cliff are also found at Heysham. Boulder clay cliffs are frequently subject to landslips. 

The cliffs at St Bees Head are also important as the only site on the eastern Irish Sea for a variety of colonial seabirds, including guillemot Uria aalge, razorbill* Alca torda, kittiwake Rissa tridactyla, puffin* Fratercula arctica and black guillemot* Cepphus grylle. They also support a variety of uncommon invertebrates, including the pill woodlouse Armadillidium pulchellum and woodlouse Trichoniscoides albidus.

The limestone cliffs of the north side of Morecambe Bay support unique ledge and limestone grassland communities, usually dominated by blue moor-grass Sesleria caerulea, with typical associated species like small scabious Scabiosa columbaria, thyme Thymus polytrichus, salad burnet Sanguisorba minor, and dropwort Filipendula vulgaris.

Current Status

Nationally important examples of hard cliffs are present at St Bees Head and around Morecambe Bay and on Hilbre Island at the mouth of the Dee Estuary. Small sections of regional importance are present at Heysham.

For further information please see the document for download on this page.