There is an ongoing project to improve the river for fish migration, with the focus on allowing salmon to return to the river to breed by 2020, but any work carried out will also benefit populations of brown trout, grayling, eels and lamprey. In 2012, most of the fish in the river were brown trout, with no established coarse fish. In order to achieve regeneration, an archaeological survey was carried out in 2012, examining the eight weirs from Stacey Wheel to Owlerton Wheels. The reason for the survey was that any modification to the weirs, which are historic structures, would require both planning consent and ancient monument consent. Modification would be necessary to provide fish passes at each of the sites.