The countryside of the Great Ouse Valley has a wonderful abundance and variety in its natural heritage - all the more valuable when contrasted with the industrial scale arable lands that characterise much of Cambridgeshire.
The meadows have species rich swards containing red fescue, crested dog’s tail, meadow foxtail, great burnet, meadowsweet, meadow buttercup, sneezewort, yellow rattle, lady’s bedstraw – and many more.
At Portholme Meadow over 200 varieties of plants are recorded; two rarities are the narrow-leaved dropwort and snakeshead fritillary. Other sites in the area record the scarce green winged orchid
The Great Ouse Valley is important for numerous bird species, including the breeding population of corn bunting at Portholme, breeding avocets and bitterns at Fen Drayton Lakes. Winter brings northern lapwing, golden plover, widgeon and black tailed godwits.
Wildlife organisations are encouraging the increase of snipe, redshank and wintering whooper and bewick swans.
Upstream from St Ives
The River Great Ouse is important for eels, spined loach, lamprey, otters and visiting grey seals. Invertebrates include the white spotted pinion moth and many dragonfly and damselfly species.