Definition
Coston Fen is a low‑lying wetland area located within the civil parish of Runhall in the county of Norfolk, England. It is recognised for its biological interest and is designated as a Site of Special Scientific Interest (SSSI).
Overview
The fen lies on the eastern edge of the Breckland landscape, close to the River Yare and the historic settlement of Runhall. The site occupies approximately 25–30 hectares (the exact extent varies between sources) and is managed to preserve its characteristic wet‑grassland and fen habitats. It is part of a network of protected wetland sites within Norfolk that support a diverse assemblage of flora and fauna, including several nationally scarce plant species and breeding birds.
Etymology/Origin
- Coston is a place‑name element common in Norfolk, historically recorded as “Coston” or “Coston‑Fen”. The name is thought to derive from the Old English personal name Cōst combined with tūn, meaning “farmstead” or “settlement”.
- Fen comes from Old English fenn, meaning “marsh” or “wetland”.
Thus, “Coston Fen” can be interpreted as “the marsh belonging to the settlement of Coston”.
Characteristics
- Habitat: The fen is predominantly a calcareous or base‑rich fen, featuring a mosaic of dykes, reedbeds, wet meadows, and shallow pools.
- Flora: Notable plant species reported from the site include Carex paniculata (greater tussock‑sedge), Juncus subnodulosus (blunt‑fruited rush), various orchid species such as Dactylorhiza maculata (heath spotted orchid), and the nationally scarce Potamogeton trichoides (hairlike pondweed).
- Fauna: The wetland supports breeding waders and waterbirds such as the grasshopper warbler (Locustella naevia), reed bunting (Emberiza schoeniclus), and occasional migrant species. Invertebrate communities include notable dragonflies and damselflies, and the site is recognized for its populations of the freshwater snail Anisus leucostoma.
- Conservation status: As an SSSI, Coston Fen is protected under the Wildlife and Countryside Act 1981. Management practices focus on maintaining appropriate water levels, controlling invasive species, and preserving the fen’s botanical diversity.
Related Topics
- Runhall – the civil parish encompassing Coston Fen, with a history dating to the Domesday Book.
- Sites of Special Scientific Interest in Norfolk – a designation applied to numerous ecologically important areas across the county.
- Fenland habitats – wetland ecosystems characteristic of eastern England, notable for their biodiversity and cultural heritage.
- Breckland – the broader natural region in which Coston Fen is situated, renowned for its unique soil and vegetation types.
Note: While the above information aligns with available official citations and regional ecological records, precise details such as the exact area size and species lists may vary between sources. Accurate, up‑to‑date data should be consulted from Natural England’s SSSI citation for Coston Fen.