Sites of Special Scientific Interest

Brent Reservoir

The Brent Reservoir is of interest primarily for breeding wetland birds and in particular for significant numbers of nesting Great-Crested Grebe. The wetlands are also of interest for their plant communities. The swamps are characteristically dominated by a single species, mainly bulrush 'Typha latifolia' and common reed 'Phragmites australis'.

North Wirral Foreshore

North Wirral Foreshore is located between the outer Dee and Mersey Estuaries. This site is an area of intertidal sand and mudflats and embryonic saltmarsh which is of considerable importance as a feeding and roosting site for passage and wintering flocks of waders, wildfowl, terns and gulls. The embryonic mixed saltmarsh is formed principally from common saltmarsh-grass 'Puccinellia maritima' and glasswort 'Salicornia europaea', together with some common cord-grass 'Spartina anglica'.

Greenham and Cookham Commons

Greenham and Crookham Commons occur on a long ridge between the Rivers Enborne and Kennet. The ridge consists of Eocene deposits of acid, sandy clays of the Bagshot Beds overlain by plateau gravels, and seated on heavy impermeable clays of the London Clay. Consequently the soils are a complicated pattern of variable deposits in which free draining soils dominate, but with clay pockets producing extensive seepage zones and springs. These springs give rise to streams creating the small, flushed and waterlogged valleys of alder woodland.

Gilbert's Pit

Gilbert's Pit provides one of the most complete sections through the Lower Tertiary beds in the Greater London area. It forms a key Tertiary site for stratigraphic studies and is particularly important for a palaeogeographic reconstruction of the Woolwich and Reading Beds. The Woolwich Beds, in particular, are noted for an abundant but very low-diversity brackish water molluscan fauna. These Beds also contain a number of named subdivisions which include the Woolwich Shell Bed and Striped Loams (Leaf-bed of Lewisham).

Lower Fal and Helford Intertidal

The Helford is notable as a natural physiographic feature, representing the range of communities which are present in an estuary from the limit of saline influence out to the open coast at the mouth. Extensive areas of sediment flats occur at the Bar round to Passage Cove, and on the opposite shore around Helford Point. A wide variety of seaweeds occur attached to the pebbles including 'Gracilaria verrucosa', 'Ceramium rubrum' and 'Polysiphonia elongata' whilst the fauna is less diverse and dominated by polychaete worms such as the sand mason 'Lanice conchilega', and hermit crabs.

Dover to Kingsdown Cliffs

Dover to Kingsdown is an internationally important stratigraphic reference site which provides extensive and near continuous cliff and shore exposures of the Cenomanian, Turonian and Coniacian Stages. The site is historically very important as many geological principles, such as biostratigraphic zonation were tested here during the early development of geology. Many parts of the succession are fossiliferous and, in particular, the upper parts of the Turonian and lower parts of the Coniacian are rich in Micraster, which have contributed, and still are contributing to our knowledge of evolution.

Lion Pit

Lion Pit exhibits a complex sequence of Pleistocene Thames deposits overlying and banked against Chalk, representing the northern edge of the river's floodplain at the time of deposition (probably equivalent to the Lynch Hill or Taplow Terrace of the Middle Thames). The deposits have yielded molluscs, ostracods and pollen, and a mid-Levallois working site has been reported on the chalk surface at the foot of the fossil cliff. Since this section has not been stratigraphically related to the established Thames Terrace sequence it requires considerable further work, for which there is great potential.

Inner Thames Marshes

The Inner Thames Marshes form the largest remaining expanse of wetland bordering the upper reaches of the Thames Estuary. The site is of particular note for its diverse ornithological interest and especially for the variety of breeding birds and the numbers of wintering wildfowl, waders, finches and birds of prey, with wintering teal populations reaching levels of international importance. The Marshes also support a wide range of wetland plants and insects with a restricted distribution in the London area, including some that are nationally rare or scarce. The marsh grasslands support a further range of important invertebrate species with differences between the grazed and ungrazed areas. Insects present and which are nationally scarce include Roesel's bush cricket 'Metrioptera roeselii', the wormwood moth 'Cucillia absinthii' and a hoverfly 'Tropidia scita'. The invertebrates supported by the areas of saltmarsh along the Thames foreshore are less recorded but include a rare spider 'Baryphyma duffeyi' (provisional RDB category 3: Rare).

Epsom Common

Stew and Great Ponds, dating from mediaeval times, are the most valuable of the open water habitats on Epsom Common. The open aquatic flora of these two ponds includes duck weeds Lemna species, white water-lily 'Nymphaea alba' and pondweeds Potamogeton species while the marginal fen flora includes great reedmace 'Typha latifolia', bogbean 'Menyanthes trifoliata', trifid bur-marigold 'Bidens tripartita' and narrow-leaved water-plantain 'Alisma lanceolatum'. Around the Great Pond a belt of sallow is present above tussock sedge 'Carex paniculata', rushes and tussock grass. Breeding birds associated with open water at this site include mallard, moorhen, little grebe and kingfisher.

New Ferry

New Ferry is a natural embayment comprising intertidal sand and mudflats interspersed with shingle and cobbles. Throughout the winter, New Ferry supports national important populations of both Pintail and Black-Tailed Godwit. These birds utilise the rich invertebrate fauna of the intertidal mudflats. These remain exposed for a significant part of the tidal cycle, which makes them particularly important in terms of feeding time available to the birds; as such New Ferry is primarily a low water feeding site.

Ashtead Common

This site is one of the most important for invertebrates in Surrey. Of particular note are the species of coleoptera (beetles) and diptera (flies) that are associated with dead wood; these include a beetle Rhizophagus oblongicollis whose national existence is under threat. Three other dead wood species are regarded as nationally rare: the beetle 'Bibloporus minutus' and the flies 'Ctenophora bimaculata' and 'Oedalea apicalis'. The fly fauna is further enhanced by the presence of two species which have their only Surrey locality here: 'Trixia coerulescens' and 'Servillia lurida'. Two notable butterflies, the purple emperor 'Apatura iris' and the purple hairstreak 'Quercusia quercus' are also present in the woodland.

A Site of Special Scientific Interest (SSSI) is an area deemed to be of special interest because of botanical, zoological or geological features that merit protection or preservation. There are more than 6,000 in Britain.

The formal notification for a new site includes a citation of the thing of special scientific interest and a map of the boundary defining the area. In some cases these sites are literally fenced off. This mode of classification of the environment reflects the discovery of knowledge whereby a new species, structure or concept is defined or acquired, and given a place in our understanding of our landscape and ourselves.

Often SSSIs are found on former industrial sites, many dating from the nineteenth century, a period when significant and related developments in industry, colonisation, classification and photographic processes and techniques occurred.

Taking a photograph is an act of visual classification in its own right. The frame imparts significance to the elements organised within it, a reflection of the cartographic border of a Site of Special Scientific Interest. Whatever is chosen for organisation in the frame adds to the sum of our visual knowledge.

With the advent of digital technology the potential sum of this knowledge is perhaps beginning to outstrip our capacity to comprehend.

Edmund Clark

Sites of Special Scientific Interest