Welcome to Dunster Beach’s 360 Interpretation Board

Dunster Beach, sand dunes and shingle ridge occur within an environmentally important 2 km long stretch of the West Somerset coast. The geological history of the coast here spans a timescale of approximately 360 million years and extends from the Devonian Period of geological time up to the present day.

 

The coastal geology and geomorphology (ground surface changes) at Dunster Beach are constantly changing even today. The constant shifting of the pebble ridges and action by the high tides means that the intertidal environment is highly dynamic. However, landward of the main beach sands, the sand dune, wetland and woodland habitats are more stable, and they are home to an important and diverse flora and fauna.

 

The geology and main features of interest are summarised on the new circular Information Board installed in the car park at Dunster Beach.

    

Jurassic fossils and Blue Anchor

West Somerset’s Jurassic Coast exposes a superb sequence of approximately 200 million year old marine limestones, shales and mudstones in impressive cliffs and extensive intertidal reefs. Many of the rocks are highly fossiliferous. The closest locality to Dunster Beach where fossils can commonly be found is at Blue Anchor, just x kilometres to the north east of Dunster Chalet Park.

The Triassic and Jurassic cliffs at Blue Anchor contain an impressive major fault along with beds of attractive white and pink gypsum (alabaster) which was formerly cut and polished for decorative items. Fossils commonly found at Blue Anchor include fossil bones, shark spines and fish scales in the fa

mous late Triassic ‘Bone Bed’ and early ammonites (called Psiloceras) in the early Jurassic grey shales and mudstones. These ammonites are amongst the oldest known in Britain and are smooth shelled, they are often preserved with a nacreous, mother-of-pearl type appearance to the shell.

 

The geology and main features of interest are summarised on the new circular Information Board installed in the car park at Dunster Beach.

  

The Brendon Hills and mines

South of Dunster Beach and surrounding Dunster Castle to the west and east, are the Brendon Hills. These hills rise to a height of 420 metres above sea level, merge into eastern Exmoor and are included within Exmoor National Park. They are formed of Devonian sandstones and slates with occasional limestones between 380 and 360 million years old. Some of these Devonian rocks contain veins of iron and copper or

e which were worked historically, none are active today. Ore from the mines was transported by the Somerset Mineral Railway to the docks at Watchet; traces of the former railway can still be seen on the West Quay of Watchet Harbour.

The sand dunes and shingle ridge

Plants and birds

The sand dunes at Dunster support an impressive and rich diversity of coastal plants, some of which are nationally scarce and specialist sand dune species.

 

During the summer months, the tall flower heads of Viper’s Bugloss, Carline Thistle and Fragrant Evening Primrose are common and very apparent; they attract a range of pollinating insects including various bees, beetles and moths.

 

      

 

 

Amongst the less conspicuous plants on the dunes are equally colourful and important species such as Hound’s Tongue, Spiny Restharrow and Biting Stonecrop along with Birds-foot Trefoil, Common Mallow and Scarlet Pimpernel.

 

     

 

Small flocks of finches can often be seen flitting between various grasses and thistles on the sand dunes – these are often Goldfinches or Linnets. A rare winter visitor to the shingle ridge and boulders along the edge of the chalets and car park is the Snow Bunting.

 

  

 

Beach Pebbles

The beach pebbles that form Dunster shingle ridge are mainly of purplish-red or grey-green Devonian quartz-rich sandstones and are approximately 380 million years old. Many pebbles contain characteristic veins or pockets of white quartz. These pebbles originate from cliffs at Minehead North Hill or further west along the Exmoor Coast and were formed by erosion of these cliffs as sea levels rose following the last glaciation around 10,000 years ago. The pebbles have been transported to Dunster by the action of the tides and longshore drift.

 

 

Sand dunes

 

The sand dunes and shingle ridge are susceptible to erosion by the sea and this is a constant issue for the management of this part of the coast. The construction of wooden fences (groynes) across Dunster beach helps to trap pebbles and maintain the position and height of the shingle ridge, whilst the planting of Marram Grass in the dunes along with the other plants, helps stabilise the sand dunes themselves.

 

 

Life on Dunster shore

 

Birds

 

The intertidal beach flats provide feeding areas for a range of birds including Herring Gulls, Lesser Black-backed Gulls and several species of waders such as Curlew, Little Egrets, Oystercatchers and Turnstones.

 

      

Often Carrion Crows, Rooks and occasionally Herons can be seen on the beach at low tide scavenging for food as well. Other ducks including Wigeon and Shelduck congregate in small flocks slightly offshore but can be easily spotted from Dunster beach.

 

 

Shellfish

 

Larger rocks, mudflats and shallow offshore areas provide valuable intertidal and shallow marine habitat for many species of gastropod and bivalve molluscs – and their shells are often found washed up and empty on the beach.

 

 

Amongst the bivalve shells, Cockles, Tellins and Carpet shells are frequently encountered whilst Whelks, Limpets, Periwinkles and Topshells are the most common types of gastropod shells seen on the beach – their thicker shells are more resistant to breakage against pebbles caused by the strong tidal currents along the shore.

 

Some species of shell are restricted to particular habitats – it is worth looking amongst the clumps of seaweeds, such as Bladderwrack for example, for the variously coloured Flat Periwinkles that live on this type of seaweed.

 

Some empty bivalve shells exhibit a small, rounded hole near their apex. These have been attacked by predatory Dog Whelks or Sting Winkles which have specialised mouth parts which can literally drill through shells and then eat the contents.

 

Woodland and Wetland birds

 

Bordering the southern grassy recreation areas that fringe the southern edge of Dunster Chalet Park is an impressive strip of mixed deciduous and coniferous woodland containing large wetland ponds. These areas support a rich diversity of wildlife and are particularly important locally for the range of different bird species they support.

 

Along with Great Spotted Woodpeckers and Jays, one of the noisiest birds present in the woodland are Rooks which nest in large numbers in the tallest trees at the western edge of the Dunster Chalet Park adjoining the Golf Course. Buzzards may sometimes also be observed circling high over the woodland areas. Amongst the smaller, more secretive birds that can be seen in the woodland areas are Treecreepers, Nuthatches, Long-tailed Tits and Goldcrests are some of the smaller, more secretive birds that may be seen in the woodlands.

 

 

 

Nestled within the woodland strip are a series of interconnected large wetland ponds that adjoin wet grassland and marshy fields north of the A39 road. These wetland areas provide important habitat for a range of birds including the ubiquitous Mallard and Canada Goose along with Grey Heron and occasional Kingfisher. The tall reed beds support breeding populations of Reed Warbler.

 

 

 

 

The woodland edges with dappled sunlight and nectar-rich plants such as bramble, are favourite haunts of numerous species of moths and butterflies including Speckled Wood, Peacock, Red Admiral and Comma.