Manuscript on reviewing citizen science in stream monitoring and restoration (11/2025)

Key messages:

1. Citizen science offers a powerful approach for monitoring rivers and assessing the effectiveness of stream restoration measures. A systematic global review synthesises information from 87 citizen science stream monitoring projects.

2. The majority of projects were located in Europe, the United States and Canada, highlighting an uneven global distribution.

3. Citizen scientists most commonly monitor biological parameters, e.g. macroinvertebrates, and hydro- morphological parameters such as e.g. stream flow.

4. The majority of projects provide training opportunities (72%), and apply data quality control measures (84%), demonstrating efforts to ensure data reliability.

5. Collaborative, locally adaptive and co-created project designs that integrate local knowledge, communities, and organisations strengthen trust, data acceptance and long-term engagement.

6. Future initiatives should build on the foundations of existing citizen science projects, including established methods, tools and data-sharing infrastructures.