Coastal wildbelt

Mudflats form in sheltered coastal areas and can be seen on estuaries at low tide. Despite their barren appearance, mudflats are rich in wildlife.

Microscopic algae, such as diatoms, thrive in these habitats and form the foundation of this nutrient-rich ecosystem. The algae coat the surface, fuelling a food web that supports a variety of invertebrates including bristle worms, mussels, shrimps and mud snails. These invertebrates are critical food sources for fish and attract internationally important numbers of wintering birds. From geese and ducks to waders such as bar-tailed godwit, avocet, curlew and dunlin, mudflats become bustling feeding grounds, especially during the winter. The iconic black and white avocet with its curled beak and the haunting call of the curlew echoing around the estuaries are just two of the sights and sounds that make these areas so special.

Beyond their role in supporting wildlife, mudflats are vital breeding and nursery grounds for fish and shellfish, helping to sustain coastal fisheries and boost the biodiversity and productivity of our seas.

Devon Special Species: Wintering estuarine birds, Dawlish Warren mudflat flies, yellow-striped bear spider (Yelland mudflats), spiny cockle, dwarf spike-rush (Avon) and triangular club-rush (Tamar),

Seagrass beds develop in sheltered intertidal and shallow subtidal areas, often growing on mudflats. Devon’s seagrass beds are primarily composed of two species of eelgrass. Dwarf eelgrass (Zostera noltii) grows on higher areas often adjacent to saltmarshes. Common eelgrass (Zostera marina) is typically found underwater in subtidal zones. However, in Devon it has also been recorded at the edges of the intertidal area.

All seagrass beds are incredibly valuable for wildlife. They provide shelter, feeding grounds and nursery areas for a wide range of marine life, including fish, invertebrates and birds. Birds, such as brent geese, feed on the eelgrass (in nationally important numbers on the Exe, Tamar and Taw Torridge estuaries) and others feed on the invertebrates and fish that live in this habitat. Seagrass beds are especially important for juvenile fish and even support rare species such as seahorses.

Key areas for intertidal seagrass beds are the more sheltered south Devon intertidal areas such as the Exe Estuary, the Kingsbridge Estuary and Torbay (non-estuarine). Subtidal seagrass beds are also present in areas such as Plymouth.

Seagrass beds are under pressure from poor water quality, including increased sedimentation and turbidityThe amount of suspended particles carried in the water. More, which reduce the light that’s available and essential for growth. Anchoring and mooring activities physically damage the beds, breaking up the plants and leaving them more exposed to erosion and disease. See Key pressures and opportunities below for more information.

Devon Special Species: Wintering estuarine birds, sea horses, stalked jellyfish .

Saltmarshes are made up of salt-tolerant plants that have adapted to regular immersion by tides. They develop on mudflats in sheltered areas at the upper edge of the intertidal zone, where sedimentSmall pieces of rock, sand, mud, or organic material that settle at the bottom of rivers, lakes, or the sea. More gradually builds up. As plants colonise these areas, they help stabilise the sediment, allowing the saltmarsh to grow until only the highest tides cover it.

Saltmarsh species include native small cordgrass (Spartina maritima), glasswort, sea purslane, sea aster and common sea lavender. Saltmarshes are rich in invertebrates and provide important high-tide refuges and feeding grounds for birds, especially during the winter months.

In Devon, saltmarshes are found in most estuaries, with key areas including the Exe Estuary, Taw-Torridge Estuary and the Kingsbridge Estuary.

Historically, large areas of saltmarsh were drained for agriculture or reclaimed for development, permanently changing the natural landscape. Today, with rising sea levels and limited space for inland migration, remaining saltmarshes are increasingly at risk of permanent submersion. See Key pressures and opportunities below for more information.

Devon Special Species: Wintering estuarine birds

Organic reefs are structures formed by living organisms such as mussels, oysters and reef-building worms. They can be found in both estuarine and rocky shore environments. Blue mussel beds and sabellaria alveolata reefs are both UK Priority Habitat.

Blue mussel beds are primarily composed of Mytilus edulis and often form on rocks or firm mud, which the mussels attach themselves to using strong threads called byssus. Native oyster (Ostrea edulis) beds are mainly found along the south Devon coast. They grow on hard surfaces or old oyster shells and create layered, reef-like structures.

Mussels and oysters reproduce by releasing eggs and sperm into the water. The fertilised larvae float for a while before sinking and settling on a surface. Over time, as more individuals settle and grow, they form dense clusters. Crabs, shrimp, worms and small fish often live among the shells and seaweed grows on their surfaces. These habitats also attract birds and wading animals that forage for food.

The honeycomb worm (Sabellaria alveolata) is a reef-building marine worm found across Devon in places such as Westward Ho!. The worms build protective tubes from sand and shell fragments, creating dense, honeycomb-like structures that can form large reefs up to several metres across and a metre deep. They thrive in more exposed areas where wave action and currents supply the sand needed to maintain and expand the reef.

The Pacific oyster is an invasive species with an aggressive growth rate that threatens native habitats. It can rapidly blanket coastal areas, outcompeting native species and changing the structure of these delicate ecosystems. See Invasives for more information.

Devon Special Species: Native oyters

Dense forests of seaweed or large marine algae are vital components of the coastal ecosystem. These underwater habitats provide shelter and food for a wide variety of marine life, including fish, crabs and sea urchins.

Seaweeds are broadly grouped into three main types: green, red and brown algae, each thriving in different conditions and depths. Among the most iconic are the kelps, large brown algae that form extensive underwater forests in deeper waters.

In shallower areas, species like thongweed (Himanthalia elongata) create striking, ribbon-like structures that are a distinctive and beautiful feature of the Devon coastline.

The steep wooded banks in Devon’s estuaries are a distinctive and ecologically valuable feature. Native trees, such as oak, alder, willow and ash, often grow right up to the water’s edge. Their branches overhang the estuary, where the highest tides ‘salt-prune’ the lower twigs, creating a distinctive, level line of foliage during the growing season.

Fallen branches, limbs and even entire trees, provide shelter, spawning grounds and nursery habitat for a variety of estuarine fish, including bass and mullet. Rare bryophytes (mosses and liverworts) and fungi thrive in the humid, shady conditions.

Devon is considered a national stronghold for these habitats as over 40% of the UK’s temperate mangroves are found here.

Devon Special Species: Bryophytes of south Devon wooded creeks including awl leaved ditrichum and Turner’s threadwort.

Saline lagoons are shallow coastal water bodies that are partially separated from the sea by natural barriers or (as in Seaton Wetlands) by engineered structures called ‘self-regulating tidal exchange gates.’ They contain a mix of seawater and freshwater, creating brackish conditions that vary with tides, rainfall and evaporation.

The best example of saline lagoons in Devon is found at Seaton Wetlands, which includes an intertidal lagoon adjacent to the Axe Estuary.

Brackish reedbeds are unique wetland ecosystems primarily dominated by common reed (Phragmites australis) and other salt-tolerant plant species. They’re used as a refuge for fish, including young eels, and provide vital roosting and feeding sites for birds. Brackish reedbeds can be found across all of Devon’s estuaries.

Coastal grazing marshes are low-lying, wet grasslands that have generally been created from intertidal habitats for grazing livestock. They’re characterised by a network of ditches and pools that hold water throughout the year, creating a mosaic of wet and dry areas.

Ditches and pools in the marshes provide habitat for amphibians, fish and aquatic invertebrates. Marshes are particularly important for birds, providing breeding sites for waders and waterfowl and feeding grounds for migratory birds. Breeding avocets became extinct in the UK in the 19th century due to habitat loss and hunting. They re-colonised the Suffolk coast in 1947 and in 2023 returned to Devon to breed at Seaton Marshes. Pintail feed on plants in grazing marshes and other estuarine habitats, particularly on the Exe Estuary with smaller numbers at Kingsbridge and the Taw-Torridge.

Wildlife-rich grazing marshes in Devon include Exminster Marshes, an RSPB reserve on the Exe estuary, and extensive marshes on the Axe estuary managed by East Devon District Council.

Devon Special Species: Estuarine birds, Norfolk hawker and scarce chaser (both dragonflies found at Exminster marshes.

Sand dunes form when wind-blown sand accumulates above the high tide line. They’re shaped by natural forces and vegetation, gradually developing into a series of ridges and slacks that support a rich variety of plant and animal life. In Devon, sand dunes are vital habitats for rare and specialised species, including sea holly, sand spurges and the elusive petalwort. These dynamic landscapes also support a rich variety of insects and provide a crucial refuge for ground-nesting birds.

Sand dunes are found across Devon’s coastlines. Five of the largest sand dune systems include Braunton Burrows SSSISite of Special Scientific Interest More and SACSpecial Area of Conservation More, Northam Burrows SSSI, Croyde and Woolacombe dunes along the north coast, and Dawlish Warren SSSI and SAC on the south coast. Other smaller dunes can be found at places such as Bantham, as well as remnant dune features in areas like Exmouth. 

Sand dune systems are composed of a range of habitats which develop over time due to a range of factors such as exposure to the sea and moisture. 

• Embryo dunes are found in the most exposed locations and form by sand accumulating around plants. 
• Foredunes (also known as yellow dunes) are slightly more stable. Marram grass is common which traps more sand and develops higher dunes.  
• Fixed dunes (also known as grey dunes) are further in land where the sand is more stable. More plants and grasses are able to grow here along with lichens and mosses. 
• Dune slacks are the wet low-lying areas between dunes. 
• In the most stable and nutrient rich areas away from the sea mature vegetated dunes develop often with heath species (heathers and gorse), scrub or woodland.   

Devon Special Species: Sand dune moth group, northern Devon sand dune fly group, Brown-banded carder bumblebee, A click beetle, Dicronychus equisetioides, Sand bowl snail, Sand dune plants (sea stock, round-headed club rush, water germander, Warren crocus), Sand dune bryophytes, Sand dune fungi, Maritime lichens.

Vegetated shingle is a unique coastal habitat found on shingle beaches. It supports a variety of specialised plants that can tolerate the harsh conditions of salt spray, wind and shifting stones. These plants help stabilise the shingle, providing a habitat for invertebrates, birds and other wildlife.

Common species include sea kale and various lichens and mosses.

Devon Species of Conservation Concern include the grey bush-cricket and Cepero’s groundhopper (both also found on sand dunes).

Devon Special Species: Scaly cricket found on the shingle at Branscombe and sea spurge tortix moth on the shingle at Slapton (within the coastal moth group).

Rockpools form in natural hollows and man-made crevices along the shore, trapping seawater as the tide recedes. These miniature marine worlds offer a fascinating window into coastal biodiversity, teeming with life such as crabs, starfish, sea anemones, and small fish and shellfish.
The shores around Lundy Island are especially rich in rockpool life, thanks to the island’s designation in 1973 as the UK’s first Marine Protected Area.

Sea caves are fascinating natural formations created by the relentless action of waves eroding the coastal cliffs over millennia. Found along rugged coastline, particularly in areas like Torbay and the north coast, sea caves are typically carved into soft sedimentary rocks such as limestone or sandstone. Many are accessible only by boat or at low tide, revealing intricate patterns and textures formed by geological processes. Sea caves provide habitats for species such as sponges, molluscs, small fish, crustaceans and even bats. They’re also significant features in several of Devon’s protected sites.

Devon Special Species: Grey seal, Celtic sea slug (north Devon rocky shores), Tompot blenny, Stalked jellyfish, Glaucous pimplet

Maritime cliff and slopes is the name given to the mosaic of habitats found between the bottom of a cliff and the the inland limit of salt spray (which can be up to 500m in exposed areas).

This mosaic of habitats includes rocky cliffs, sunny grasslands, scrub, woodlands, streams and wet flushes. Together these habitats provide nesting sites, food and shelter for a wide range of species.

The vegetation is very diverse reflecting the diverse geology along the two coasts. A number of stretches support specialist species due to the underlying geology.

Sidmouth to Dorset Coastal Wildbelt

• Between Sidmouth and Dorset the cliffs are formed from layers of chalk, limestone and mudstones. Landslips along these cliffs have created what are known as the ‘undercliffs’ . These undercliffs support scrub, grasslands, stream and wet areas and are of huge wildlife value, especially for insects.
• Devon Special Species include:
  • Insects: Broad-faced furrow bee and buff-banded mining bee. Spanish snout cranefly, least cigar-gall fly and other flies. Moths including Morris’s wainscott, white spot, Devonshire wainscott, everlasting pea blister. Wood white butterfly. Cliff tiger beetle.
  • Plants: Nottingham catchfly, early gentian, white horehound
  • Bats: Greater horseshoe, lesser horseshoe and Bechstein’s bats roost in the chalk caves at Beer and forage in nearby grasslands.

Torbay Limestone Coastal Wildbelt

• Cliffs at Torbay are formed from hard limestone which erodes to form sea stacks and caves. Rare specialist lime loving plants, lichens and mosses grow in the coastal grasslands.
• Devon Special Species include:
  • Cliff nesting seabirds
  • Insects: Torbay limestone moths such as the goldilocks case bearer. Roundhead roughneck rover beetle,
  • Rare whitebeams and Torbay limestone specialist plants such as goldillocks aster and white rock-rose.
  • Maritime lichens and bryophytes.

Start Point to Bolt Tail Coastal Wildbelt

• Cliffs in this stretch of the south Devon coast are formed from metamorphic rocks overlain by loose rock fragments (known as ‘head deposits’). They also have ancient ‘raised wave-cut platforms’ which are flat rock surfaces created by erosion when the sea level was much higher than today. These platforms are now way above sea level. The unique geology along this stretch of coast in turn supports rare species.
• Devon Special Species:
  • Brown-banded carder bumblebee, six-banded nomad bee and long horned bee.
  • Devon red-legged robberfly
  • The moon spider and other rare Prawle cliff spiders.
  • Shore dock and slender bird’s-foot trefoil
  • Maritime lichens

Lundy Coastal Wildbelt

• Lundy is composed of granite and has at least 38ha of maritime cliff and slope. It is particularly important for nesting seabirds.
• Devon Special Species:
  • Nesting seabirds including puffin and manx shearwater.
  • Lundy cabbage and the Lundy cabbage weevil and flea beetle which live on it.

Cornwall to Morte Point and Morte Point to Somerset Coastal Wildbelts

• The north coast cliffs are largely made of sandstone. The Exmoor coast has hard sandstones which create a dramatic coastline of high, steep cliffs between Woolacombe and Somerset. This includes Great Hangman which is the highest cliff on the English coast.
• Devon Special Species:
  • Rare whitebeams on the Exmoor coast.
  • Moss carder bumblebee and brown-banded carder bumblebee on the coast around Braunton.
  • Insects (also found on the south Devon coast) such as lizard weevils, the variable meadow fly and coastal moths such as Devonshire wainscott and scarce blackneck (only found in north Devon).