Environment Agency: A new DNA method that could revolutionise the way fish are monitored in lakes has been shown to detect 14 of 16 key fish species known to be present in Lake Windermere, compared to just four species found by conventional surveys. Fish are sensitive indicators of water quality and their assessment is an important part of water management. In England, Wales and Scotland regular lake fish monitoring is not feasible with existing tools and resources. Netting can capture all the fish in an area, but it is costly and can injure or kill fish. The research project tested a new approach to assess both the type and numbers of fish present in three large lakes in Cumbria (Windermere, Bassenthwaite and Derwentwater). The approach uses environmental DNA (eDNA) – the DNA that fish leave behind in the water from their skin, urine or faeces. The eDNA can be used to provide information on fish living in the lake. New technology allows all the DNA in a water sample to be sequenced and identified. According to the Environment Agency, the multi species identification method is rapid and sensitive and has real potential to change the way it carries out ecological assessments.