Introduction
The Somerset Wetlands NNR has amalgamated the six former individual NNRs of Bridgwater Bay, Ham Wall, Huntspill River, Shapwick Heath, Somerset Levels and Westhay Moor, along with a number of other nature reserves. The NNR sits within the Somerset Levels and Moors, which is the largest remaining area of lowland wetland in England. The large scale of the wetland habitats on the reserve are a haven for wildlife and internationally important for a variety of species including the large numbers of wildfowl and wading birds that over-winter here.
The site provides habitats for a diverse range of wetland wildlife including a third of the UK’s bittern population, breeding avocets and new colonisers like the great white egret and common crane. It is a hotspot for reptiles like adder and grass snake and home to a host of frogs, toads and newts.
The sprawling reedbeds, saltmarshes, and wet grasslands support otter, water vole and more recently, the beaver.
Inland, most of the wet fen and mire sites have been transformed from abandoned peat workings into lush wetlands, while out on the Steart Marshes large areas of saltmarsh are being created as part of improved flood management along the coast.
Covering 6,140 hectares, this new National Nature Reserve is leading the way in wetland conservation in England.
Habitats
The Somerset Levels and Moors are the largest area of lowland wetland remaining in England and the UK’s second largest area of lowland peat.
Inland, the NNR is a mosaic of wet grassland, fen, mire, reedbed, lakes, waterways and wet woodland, and these habitats transition into floodplain grazing marsh, salt marsh and intertidal mudflats as they reach out into the Severn Estuary.
Open water
Open water is present on many of the deeper peat cuttings, offering good refuges for wildfowl, grebes, coot and moorhen. The large numbers of amphibians found in these areas, including the introduced Iberian water frog, provide food for the many herons and egrets.
Open water and the surrounding vegetation are important for the large range of dragonflies that live within the Levels and these in turn attract good numbers of hobbies that hunt over the water feeding on them.
The fish that thrive in these areas attract kingfisher and otter.
Reedbeds
Large areas of reed swamp surrounding open water have been created on areas of past peat extraction, and this has provided ideal habitat to allow the expansion of the bittern population. Other birds using this habitat include marsh harriers, reed and sedge warblers and water rail.
Large expanses of reedbed can be found Ham Wall and out at Steart Marshes.
Fen and mire
Vast areas of raised bog (or mire) would have been a distinctive feature of the Somerset Levels, but almost all have been lost to peat extraction. Westhay Moor now contains the largest surviving fragment of lowland acid mire in South-West England. Here you will find sundews, cotton grasses, sphagnum mosses, marsh pennywort and bog myrtle.
Areas of sedge-dominated fen can be found at sites such as Catcott and Shapwick, where our smallest rodent, the harvest mouse can be found. These nationally rare sedge meadows have a diverse range of plants including marsh marigold, ragged robin, meadowsweet and southern marsh orchid.
Wet grassland
In sites such as Shapwick Moor, the raising of water levels and the re-establishment of traditional hay meadow management has helped to increase the plant diversity and wildlife interest. These areas are now important for wintering wildfowl, snipe, lapwing, starling, reed bunting and stonechats. The rough grassland edges to some of these meadows abound in voles and mice, which in turn, attract kestrels and owls.
Wet woodland
Areas of wet woodland, dominated by willows are present on many of the sites in the NNR such as Shapwick Heath where plants such as marsh fern and royal fern can be found.
Ditches and waterways
The network of ditches or rhynes, developed to drain the peatlands for agriculture are now more often used to raise water levels and keep the peat wet. They provide another important habitat for a range of rare plants and are the best place to see water vole.
Saltmarsh
Steart Marshes and Bridgewater Bay have large expanses of saltmarsh with typical plants such as sea purslane and scurvy grass. These are important feeding grounds for wintering wildfowl.
Mudflat
Bridgewater Bay is one of the largest areas of intertidal mudflat in England. The Bristol Channel experiences the second biggest tidal range in the world and at low tide huge areas of mudflat and sand bank are exposed. This attracts internationally important numbers of wildfowl and waders, which feed on the marine invertebrates that live in the mud.
Key species
Breeding birds
The freshwater wetlands provide ideal nesting areas for waders including lapwing, snipe and redshank along with other birds such as yellow wagtail. Great white egret and common crane are now breeding along with bittern, marsh harrier, cuckoo, hobby and cetti’s, grasshopper, sedge and reed warbler. Osprey pass through and it will hopefully only be a matter of time before they take up residence too.
The saltmarshes at Steart Marshes support good populations of skylark, reed and sedge warblers, along with oystercatchers and avocets. Peregrines, marsh and hen harriers are attracted to the area to feed on the large numbers of waders and wildfowl, whilst short-eared and barn owls predate on the voles and mice living in the grassland.
Wintering wildfowl
In the winter, high water levels on the peatlands and their associated grasslands attract large flocks of wigeon, teal, pintail, gadwall, shoveler and mute swan with smaller numbers of whooper and Bewick’s swan.
In July, up to 4000 shelduck arrive at Bridgewater Bay in order to moult their feathers, making it the largest moulting site in the country. These large sandbanks offer the birds a safe haven from predators, as unlike most other birds, shelduck lose all their wing and tail feathers at the same time making them unable to fly for up to a month. In winter the mudflats also attract large flocks of teal and wigeon.
Wintering waders
The freshwater areas of the NNR attract large wintering flocks of lapwing, snipe and golden plover.
Bridgewater Bay is nationally important for wintering dunlin, curlew and grey plover.
Invertebrates
19 species of dragonflies including hairy dragonfly and ruddy darter give this site a ‘Merited Site of National Importance’ by the British Dragonfly Society.
As would be expected from a large wetland site there is a long list of aquatic and wetland invertebrates . These include rare species such as the lesser silver diving beetle (only recorded in Cheshire and Somerset) and raft spider.
Butterflies include purple hairstreak, silver washed fritillary and white admiral.
Mammals
The site attracts a variety of wetland mammals including otter, water vole, harvest mouse, water shrew and recently, beavers have found their way here.
Bats include lesser and greater horseshoe and brown long-eared.
Wetland plants
Plants range from bog plants to saltmarsh flora.
In summer, the wet meadows are carpeted in a range of flowers including devil’s bit scabious, marsh pea, meadow thistle, and lesser butterfly, fragrant and southern marsh orchids.
The network of ditches or rhynes found, for example, in Southlake Moor, support a wealth of rare plants including greater water parsnip, rootless duckweed, tubular water dropwort and frogbit.
Southlake Moor and other similar sites are also important areas for threatened stoneworts (a complex algae) such as the rare great tassel stonewort.
Amphibians and reptiles
The mosaic of wetland habitats provide ideal conditions for frogs, toads and newts as well as reptiles such as adder, grass snake and slow worms.
Fish
The network of rhynes, ditches and rivers support a rich variety of fish including pike, roach, tench, perch, three-spined stickleback, river lamprey and the critically declining European eel.
Further info
Somerset NNRs:
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