This work is part of OTTERS - citizen science for water stewardship - WP2: "The large body of EU projects and programs with citizen science experience as well as recent publications on the topic will be surveyed to identify insights, lessons learned, and knowledge gaps with respect to the three broad issues outlined in the WP Objectives section above. The review will focus on identifying factors that can contribute to greater effectiveness of CS in participatory researchers and innovation. It will see if there are novel ways in which CS can contribute to such research. The project and literature survey will also focus on understanding how much we know and understand (and gaps in knowledge) about the effectiveness of CS in changing behaviour of people (esp., young ones) toward more marine and freshwater ecosystems. Does engaging in CS increase ocean literacy and agency? Does it make people behave more responsibly? What evidence is cited for such behavioural change? Finally, the project and literaturesurvey will look into experiences, opportunities, and challenges of engaging special stakeholders. The reviews will besummarised into 3 draft white papers." Please contact Dor Edelist at blackreefs@gmail.com for any enquiries about the present work. This paper focuses on the role of citizen science in helping achieving the implementation of MSFD. The paper provides a list of key citizen science projects collecting data from marine water bodies in Europe, and investigates how citizen science can aid official scientific data sources to improve MSFD monitoring. The paper also provides a list of key citizen science contributions to MSFD divided by MSFD descriptors, with special focus on jellyfish and marine litter projects.

This is one of three deliverables from the WP2 of EU-funded project "OTTERS - citizen science for water stewardship". The other two deliverables - also published in Zenodo - are titled "Riparian Ecotone Citizen Science" and "The role of citizen science within WFD and SDGs, and how to incentivize the collaboration with environmental regulators".