Evaluation of a citizen science platform for collecting fisheries data from coastal sea trout anglers

There are often limited data available to support the sustainable management of recreational fisheries. Electronic citizen science platforms (e.g., smartphone applications) offer a cost-effective alternative to traditional survey methods – but these data must be validated. We compared sea trout (Salmo trutta) data from a Danish citizen science platform with three independent traditional surveys: a roving creel survey, an aerial survey, and a recall survey. The comparisons include fisheries data (e.g., catch, release, effort, and size structure) and demographic descriptors (e.g., age) that were collected within the same spatial and temporal frame. We found general alignment between recreational sea trout catch and effort data that were provided by citizen scientists, or collected by more traditional survey methods. Our results demonstrate that citizen science data have the potential to supplement traditional surveys, or act as an alternative source of catch and effort data. However, results were from a highly specialized fishery within a limited spatial and temporal frame, so more research is needed to assess their relevance over time and to a broader set of fisheries.