Goals and approaches in the use of citizen science for exploring plastic pollution in freshwater ecosystems : a review

The role of citizen science in environmental monitoring has received significant interest in the research community over the last decade; with citizen scientists playing a key role in engaging with, and gathering, scientific evidence to support natural resource management. The involvement of citizen science in aquatic research is growing. Recent studies highlight the successful application of citizen science to support plastic pollution research within marine systems. In contrast, our knowledge on how citizen science can support plastic pollution research in limnetic studies is limited, with no known published systematic reviews on this topic. The involvement of citizen science within hydrological monitoring has been widely discussed, however, the majority of reviewed literature focuses on commonly targeted water quality parameters (i.e. nutrients). This review, for the first time, explores the current status of freshwater citizen science focused on plastic pollution based on a synthesis of 12 peer-reviewed publications. In this paper we consider the environmental and geographic extent of the research, scope and methodological approaches taken, involvement of citizen science within the research and the quality of the data collected. Alongside this, emerging issues in freshwater are also discussed with a strong focus on how citizen science can contribute to this growing knowledge pool. The use of citizen science within the field of freshwater plastic pollution remains niche, with the majority of projects following the contributory model of citizen participation. The inclusion of methods and standardized approaches relating to citizen recruitment, engagement and training in the peer-reviewed literature are limited; with greater transparency key to opening up citizen science potential within this evolving research field