Return to contents page

13. Nature conservation and wildlife

Who does what?

o. The Department of the Environment and the Welsh Office are responsible for government policy, guidance and funding. Specifically they are responsible for:

o. English Nature and the Countryside Council for Wales, are responsible for advising Government on nature conservation matters, identifying and notifying biological and earth science Sites of Special Scientific Interest (SSSIs), as well as those meeting criteria for international and European wildlife designations and ensuring appropriate management of such sites.

o. The Environment Agency has a duty to promote conservation through its water management activities and to have regard to conservation in its pollution control activities.

o. Planning authorities play an important role through statutory development plans and control of development, producing countryside strategies and management plans, as well as identifying second tier sites and undertaking direct management of some local nature reserves.

o. Non-governmental organisations such the Wildfowl and Wetlands Trust, wildlife trusts and the Royal Society for the Protection of Birds aim to increase environmental understanding as well as owning and managing land for nature conservation.

Stated Government aims


The estuary is an internationally important conservation area. This value has been recognised by the UK Government, the European Union and the international community.

The estuary is one of the largest in Britain with an extremely large tidal range which, combined with its funnel shape, creates a unique, highly dynamic environment. It supports a range of distinctive benthic communities. These include the most extensive subtidal reefs of the tube-building worm Sabellaria alveolata in Britain.

The broad intertidal sand and mudflats are home to species of worms, snails and crustaceans which provide food for the many migratory waterfowl (wildfowl and wading birds) that visit each year. In winter, the estuary regularly supports nationally important numbers of ten species of waterfowl whilst a further six species occur in numbers of international importance: dunlin, Bewick's swan, European white-fronted goose, shelduck, gadwall and redshank. The latest Wetland Bird Survey counts indicate that the Severn Estuary supports over 100,000 waterfowl (5-year mean 1990/91-1994/95), including 24,000 wildfowl (geese, ducks, swans and grebes) and over 76,000 wading birds. It is also nationally important for several species of passage migrants in the spring and autumn, including ringed plover and whimbrel. The wading birds feed on the mudflats when they are exposed, roost during the high-tide period, and are sometimes sensitive to disturbance.

The estuary is home to the world renowned Wildfowl and Wetland Trust reserve at Slimbridge. The New Grounds there support more than half the Russian population of white fronted geese and a flock of over 5000 is regularly seen. Up to 400 Bewick's swans (about 5% of the West European population) have also been seen at the New Grounds and flocks occur in many other parts of the estuary.

Common species such as mallard, widgeon and shelduck are found in many parts of the estuary with major concentrations at Bridgwater Bay and Slimbridge where there are protected feeding grounds and roosts.

Thousands of birds are attracted to the estuary by the millions of tiny animals which thrive in the mud and sand of the estuary. The most numerous of these wading birds, are the dunlin, with some 40,000 overwintering on the Severn and stopping off during migration in both the autumn and spring. Other waders common on the estuary during winter include redshank, knot, ringed plover and grey plover. Another wader which stops off in the estuary during spring and autumn migration is the whimbrel. Over 2000 birds have been recorded at Stert in May representing over 75% of the whimbrel recorded in Britain at this time of year.

Saltmarsh is a significant and threatened habitat of the estuary's fringes. There are several different community types with both gradual and stepped transitions from bare mud to upper saltmarsh. They are threatened by erosion and their plant communities are influenced by the levels of grazing by sheep or cattle. Several nationally rare or notable species are present.

Other habitats around the estuary include sand dunes, downs, cliffs, rocky shores, shingle ridges, saline lagoons, freshwater, reedbeds and the low-lying pasture around Slimbridge and on the Somerset and Gwent Levels. The Levels are the result of land-claim and form an extensive area of wet pasture drained by a network of ditches, the continued management of which is vital for maintaining their conservation interest. Many of these habitats support rare and notable species. There are extensive sea defence works, often earth embankments, and these too support some notable plants.

In addition, over 80 species of fish have been recorded which is more than any other British estuary. They include 7 migratory species such as salmon, eels, the rare allis and twaite shads, sea trout and the sea and river lampreys. Otters appear to use the edge of the estuary to move between inland rivers.

The Severn Estuary area has long been recognised as being of particular importance for earth science, a fact which is reflected by the number of sites along the estuary considered to be of at least national importance on geological grounds alone.

The Lilstock-Blue Anchor site is the most significant - a standard for the Hettangian Stage of the Lower Jurassic, it is therefore the section to which all strata of similar age throughout the world are compared.

Six other sites are of national importance, amongst which Southerndown Coast, Sutton Flats, Barry Island and Penarth Coast Sites of Special Scientific Interest (SSSIs) provide the best illustration in Britain of particular geological features. Brean Down SSSI gives evidence of former environmental conditions, whilst Spring Cove and Middle Hope SSSI provide evidence of volcanic activity during Lower Carboniferous times. Garden Cliff, Wainlode Cliff and Aust Cliff SSSI provide sections of three classic Rhaetian sites which display the most important lateral variations recorded at this level in the geological column.

As Map 13 shows, much of the estuary is covered by three large Sites of Special Scientific Interest; the Upper Severn SSSI, the Severn Estuary SSSI and Bridgwater Bay SSSI and National Nature Reserve. These sites include only those areas above Mean Low Water. Also within the estuary, are the three island SSSIs of Sully, Flat Holm and Steep Holm. These sites are of geological and geomorphological, as well as biological interest.

These national designations have been added to by two international designations which emphasise the estuary's importance: The Severn Estuary has been designated as a:

The former was designated under the EC Directive on the Conservation of Wild Birds on the basis of the estuary's overwintering bird population. The latter designation, under the terms of the Ramsar Convention, is based on the estuary's physical features, unusual estuarine communities, migratory fish and bird populations.

A slightly larger area, including the subtidal zone, is currently under consideration as a possible Special Area of Conservation (pSAC) under the EC Habitats Directive. The site has been recommended because it contributes to the essential range and variation of estuaries as the best example in the UK of a large turbid-water estuary with an exceptional tidal range. Its subtidal sandbanks, intertidal sand and mudflats and Atlantic salt meadows contribute to the habitat diversity and intertidal importance of the site and are the habitats of European importance.

Around the estuary itself there are other sites of conservation importance including 2 National Nature Reserves, Local or County Trust Reserves, a Wildfowl and Wetlands Trust Reserve and many other sites of local importance. Sites of Special Scientific Interest are shown on Map 13.

Map 13: Designated conservation areas


Many issues in this report are related to one another. Issues raised in this chapter have particular links with those in chapters 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, and 15.


N1 The loss and deterioration of wildlife habitats and diversity of wildlife

There has been a net loss of wildlife habitats, and in the diversity of wildlife - bio-diversity. The causes are many and include urban development and the consequent need for coastal defence, changing agricultural practices and pollution. Nature reserves and specific designations protect some habitats and species but they do not provide protection to the wider environment, which some people believe is necessary.

Who is involved: Planning authorities, developers, Environment Agency, English Nature, Countryside Council for Wales, voluntary conservation organisations, landowners, MAFF, FWAG, ADAS and others.

What is happening: Development plans include sections that relate to the environment, nature conservation and the wider countryside. Some local authorities have produced nature conservation strategies and the countryside agencies are working with others to produce countryside strategies to further influence the Local Plans and the new Unitary Development Plans. Specific issues relating to nature conservation will be addressed by the scheme of management that will be prepared for the Severn Estuary pSAC and will also form part of the Severn Estuary Strategy.

Some suggestions: Public involvement could be increased through the Severn Estuary Strategy process and Local Agenda 21. A more holistic view of nature conservation as part of the wider environment of the estuary could be developed.

N2 The impact of development on areas of conservation value

See issue D3 in chapter 3

N3 Public concern about the effects of sea defences and coast protection on nature conservation

See issue C5 in chapter 5

N4 The effect of recreational use on wildlife

See issues in chapter 6

N5 Concern about the effects of dredging on wildlife

See issue A4 in chapter 9.

N6 Public concern about the effects of pollution on wildlife

See issues W11 - W17 in chapter 8.


N7 Concern about the effect of the proposed Special Area of Conservation (pSAC) on other activities

There is widespread concern that the proposed Special Area of Conservation (pSAC) will severely restrict other activities in the estuary. In particular, port development, shipping, recreation and flood defence. (See chapter 15 on for further details on the pSAC)

Who is involved: English Nature, Countryside Council for Wales and all Relevant and Competent Authorities under the EC Habitats Directive

What is happening: A shadow scheme of management is being prepared by the Relevant Authorities around the estuary. Conservation agencies and users of the estuary need to develop a common understanding of the implications of the SAC for activities in the estuary. This will be achieved by consultation with a wide range of organisations and estuary users.


N8 Lack of funding for conservation initiatives

Conservationists are concerned that initiatives to encourage nature conservation are not properly funded. These include habitat management schemes for agricultural land and measures to manage nature reserves.

Who is involved: Department of the Environment, Welsh Office, MAFF, Welsh Office Agriculture Department, Agricultural Development Advisory Service, English Nature and Countryside Council for Wales.

What is happening: Consideration is being given to changes to the Common Agricultural Policy funding.

Some suggestions: Funding departments and conservation organisations could consider whether the initiatives are adequately funded and if necessary how additional funds can be secured.

N9 Water level management of wildlife habitats

On the Somerset and Gwent Levels, in the upper estuary and tidal river there are important wetland areas where water level management can influence the drainage pattern and consequently, the ecology. There are now very few breeding waders in these areas. The effect of water level management is likely to have less of an impact than land drainage practices. Water level is managed by weirs and is more likely to be influenced by flood control works than by river regulation and abstraction. All the factors need to be carefully evaluated.

Who is involved: Environment Agency, English Nature, Countryside Council for Wales, Internal Drainage Boards and landowners.

What is happening: Water Level Management Plans are being prepared for all water dependant SSSIs where the water level can be controlled.

Some suggestions: Similar plans could be developed for other wildlife areas not designated as SSSIs.

N10 Management of agricultural grazing of saltmarshes

See issue R7 in chapter 4

Return to contents page