A study into the River Trent says the waterway is being dominated by agriculture and losing birdlife.
The OnTrent Baseline Study says 92% of the floodplain is used for farming.
OnTrent project manager, Ruth Needham, said: "The Baseline Study may provide a gloomy picture of some aspects of the Trent Valley.
"But it also highlights many of the opportunities that exist here... such as developing tourism in a sustainable way."
Other findings included:
There has been a widespread loss of natural habitats
A decline in farmland wading birds, such as lapwing and redshank
An improvement in water quality, resulting in the return of species such as salmon and otters
Ms Needham said the study would be used to identify targets for future work.
She said: "Rivers such as the Trent have a major contribution to make to the local economy, to the environment and also to people's quality of life."
The OnTrent Initiative is a partnership of public, statutory, voluntary and commercial organisations which have an interest in the river.
The River Trent flows 274km (170 miles) from its source in Staffordshire to its mouth at the Humber Estuary.