Area: 57.3 hectares.

The site is in Area of Outstanding Natural Beauty.
Walmsley Bird Sanctuary forms part of this site.
The site boundary has been amended by extension and deletion.
* The British Red Data Book lists vulnerable and endangered species. 

Description and Reasons for Notification: 

Amble Marshes are situated on the north side of the Camel Estuary along the floodplain of the River Amble some 2 kilometres north of Wadebridge. 

The Upper Devonian Slates are overlain by alluvium. The soils vary from poorly drained to well drained loams. The valley exhibits a variety of neutral unimproved, semi-improved and improved grassland with open water, scrub, and marginal vegetation habitats. Noteworthy plant species recorded here include the Red Data Book* species, little robin Geranium purpureum and the rare spiral tasselweed Ruppia cirrhosa

Amble Marshes are particularly important for their ornithology and the site includes the Walmsley Bird Sanctuary that is owned by the Cornwall Bird Watching and Preservation Society. The marshes are a traditional overwintering location for white-fronted geese Anser albifrons; having been recorded here since the nineteenth century. Peak numbers of geese have been recorded during severe winters when Cornwall often remains milder and ice free, as in 1963/64 when some 2,000 white-fronted geese were seen at Amble. During the last decade numbers of white-fronted geese overwintering in Britain have decreased and accordingly there have been limited numbers recorded at Amble. 

The ornithological importance of Amble Marshes is enhanced by its location immediately adjacent to the Camel Estuary, resulting in high winter wader and wildfowl populations particularly during high tides and gales. Peak numbers of 9–10,000 lapwing Vanellus vanellus, 1,000 curlew Numenius arquata and 1,000 widgeon Anas penelope have been noted here. 

A total of 52 species of breeding birds and some 82 wintering species have been recorded at Amble Marshes together with a large number of rare passage and wintering bird species.