Co‐design of a citizen science study: Unlocking the potential of <scp>eDNA</scp> for volunteer freshwater monitoring

Abstract Citizen science is increasingly being promoted as a means of gathering more data to help inform the management of ecosystems. Involving the participants in the design of data collection activities is a form of co‐design often proposed by those calling for a translational ecology. In addition, novel monitoring approaches have the potential to improve the quality of data collected by citizen scientists. We explored the potential of environmental DNA (eDNA) for vertebrate (mainly fish) species monitoring through a co‐designed catchment monitoring strategy. Having been introduced to the potential of eDNA, citizen scientists designed and executed an eDNA‐based survey of a small chalk stream catchment to explore questions of concern. The eDNA survey provided data about fish and other vertebrate diversity in the catchment which would have otherwise required sampling approaches difficult for citizen scientists. These data give a preliminary answer to some of the citizen scientists' priority questions and are comparable to fish data collected through traditional electrofishing surveys. Recommendations are offered for co‐design and the use of novel research techniques by citizen scientists.