Improving participated management under poor fishers’ organization: Anadromous fishing in the estuary of Mondego River, Portugal

River defragmentation works and an effective fishway with a monitoring station have created conditions for adaptive fishery management in the estuary of Mondego River in central Portugal. Since 2013 fishers, scientists and authorities annually meet to update data for anadromous fish and rules for the upcoming fishing season. Meetings provide an opportunity for approximately 100 licenced fishers to participate, but communication is often hindered by contradictory fisher views and uneven representation between fishers organized in associations (mainly in the lower estuary) and non-members (mainly in the upper estuary). This study presents a survey, voluntarily undertaken by fishers (n = 35) in the upper and lower estuary, aiming to facilitate communication and discursive rationalization of decisions during the annual meetings. The questionnaire includes perceptions of change in environmental and socio-economic conditions, opinions on rules and utility of the meetings and allows comparisons between the upper and lower estuary communities. Results were presented in the 2019 meeting, demonstrating that fishers agree with most rules but also have proposals for rule change and strengthening of participation. The decisions for the 2020 season suggest that the survey permitted a more focused discussion of alternatives and led to modification of rules by consensus that was previously unattained. The survey further showed that a wider governance structure will be required to resolve the emerging problem of an invasive water plant that reduces fishing opportunities and deteriorates river productivity