Area: 422.5 hectares.
Part of the site is listed in the Geological Conservation Review. In North Devon Area of Outstanding Natural Beauty. Part of the site overlaps with the Taw-Torridge Estuary SSSI.
Description and Reasons for Notification:
Northam Burrows is of interest for its wide range of coastal habitats and in particular for the rare and local plants to be found. The site also supports many overwintering and migratory birds. In addition, the cobble ridge is an important land-form feature.
Situated to the south of the entrance of the Taw-Torridge Estuary, Northam Burrows is a low-lying area of gently undulating sand and alluvial deposits. The land dips slightly from north and west to south and east, providing varied drainage conditions. Several pools occur and many narrow ditches criss-cross the area.
The cobble ridge protects the seaward boundaries, behind which lies a system of ‘yellow’ dunes. These are largely dominated by marram Ammophila arenaria and, together with other areas of dry grassland, support many species of plants. Red fescue Festuca rubra is abundant, with other grasses including sheep’s fescue Festuca ovina, crested dog’s-tail Cynosurus cristatus, common whitlow-grass Erophila verna and the nationally scarce dune fescue Vulpia membranacea. Wild pansy Viola tricolor, viper’s-bugloss Echium vulgare, restharrow Ononis repens, common bird’s-foot trefoil Lotus corniculatus, wild thyme Thymus polytrichus and lady’s bedstraw Galium verum are frequent here. The dunes also support the rare sea stock Matthiola sinuata and the nationally scarce bird’s-foot clover Trifolium ornithopodioides and rock sea-lavender Limonium binervosum.
Where the water table is nearer the surface, wet grassland and dune slack communities occur. These are also herb-rich with species including yellow iris Iris pseudacorus, bog pimpernel Anagallis tenella, autumn lady’s tresses Spiranthes spiralis, parsley water-dropwort Oenanthe lachenalii, adder’s-tongue Ophioglossum vulgatum, sedges Carex spp. and the nationally rare water germander Teucrium scordium.
Large areas of dune grassland and slack are dominated by dense stands of sharp rush Juncus acutus which has a nationally restricted distribution, and in places forms thickets with hawthorn Crataegus monogyna and bramble Rubus fruticosus.
Where there is a strong maritime influence a certain degree of salinity supports sea rush J. maritimus, grey club-rush Schoenoplectus tabernaemontani and the nationally scarce brackish water-crowfoot Ranunculus baudotii in the ditches.
The extensive areas of grassland provide autumn, spring and winter roosting and feeding grounds for many birds, particularly those using the adjacent estuary. Golden plover Pluvialis apricaria, curlew Numenius arquata, wigeon Anas penelope and Brent goose Branta bernicla occur in overwintering flocks. The range of habitats present also supports a diverse breeding bird community which includes shelduck Tadorna tadorna, wheatear Oenanthe oenanthe, stonechat Saxicola torquata, whitethroat Sylvia communis, grasshopper warbler Locustella naevia and sedge warbler Acrocephalus schoenobaenus.
Records to date strongly indicate that the site is also very important for many groups of invertebrates. Species of particular interest include the nationally rare woodlouse Armadillidium album, the nationally scarce Portland moth Ochropleura praecox and the squashbug Arenocoris falleni.
The cobble ridge is a classic coastal feature noted in particular for the large size of the sediments present. Few spits in Britain are formed of large cobbles at the back of an extensive sandy intertidal zone. Some of the cobble material derives from sources to the south, and sand, gravel and cobbles have moved to the distal end of the spit forming a spatulate feature in the Taw-Torridge Estuary.