Since the late twentieth century, social mobilization for the sustainable management of fisheries on the lower Amazon floodplain has been driven by community-based fishing agreements. To support this process, we developed PescaViva, a serious game designed through participatory modeling. The Lago Grande do Curuai (LGC) region was selected as the study area due to its fishing significance and the pressures on its fishing stocks. Fieldwork began in 2021 with the formation of a focus group comprising fishing leaders, representatives from the LGC region, and environmental agencies. To date, we have conducted ten game co-construction workshops with the focus group and nine workshops with local fishers in their communities. A key outcome of this collaborative process is the creation and maintenance of a space for dialogue and interaction between grassroots organizations and government institutions, fostering sustainable fisheries management in the region.