The reserve is unusual in that it consists of two divergent habitat types: intertidal mudflats (fringed by saltmarsh and estuarine reeds), and 130 acres of deciduous woodland, mainly oak and coppiced sweet chestnut.
The estuary is important as a breeding, roosting and wintering site for many waterfowl and other birds, including woodpeckers, Nightingale, Blackcap, Whitethroat, Sedge Warbler, Reed Warbler, European Wigeon, Shelduck, Pintail, Teal, Dark-bellied Brent Goose, Grey Plover, Redshank, Curlew, Dunlin and Black-tailed Godwit.
Mammals to be seen include Red Fox Vulpes vulpes, badger Meles meles, Grey Squirrel Sciurus carolinensis, and Hazel Dormouse Muscardinus avellanarius.
Butterflies and rare moths include White Admiral Limenitis camilla, Chocolate-tip Moth Clostera curtula and Peach Blossom Moth Thyatira batis.