How citizen scientists can enrich freshwater science as contributors, collaborators, and co-creators

The involvement of volunteers in aspects of freshwater research and monitoring has a long history. However, the advent of smart technology and access to the internet has opened up the possibility of mass public participation in science, termed citizen science. The potential of citizen science to generate data over wider spatial and temporal scales than conventional approaches is well recognized. However, as the field of citizen science has matured, more attention is being given to the participant journey, and how practitioners can maximize engagement. The papers in this special series on citizen science and freshwater are collected from a range of initiatives, with each study operating in different environments and engaging with citizens with contrasting socioeconomic circumstances. Many of the studies result in insights into freshwater biodiversity (e.g. amphibians, fish, wetland birds), whereas others explore the abiotic environment (e.g. water quality, flow regimes). In addition, several papers assess volunteer participation dynamics and provide guidance for those considering the use of citizen science. The use of citizen science in freshwater science is growing and so too is the quality of the scientific outputs. In part, this growth has been caused by a gradual evolution and expansion in the approach, which involves volunteers as sensors, collaborators, and co-creators. This flexibility holds great promise for opening a new source of valuable freshwater data and knowledge