Rapidly declining seagrass meadows in Brazil: Findings from satellite imagery and local knowledge

Abstract Due to the limitations of individual monitoring approaches, integrating social perceptions with multiple advanced technologies provides a new opportunity to gain a comprehensive understanding of ecosystem degradation. We combined historical aerial mapping, satellite imagery, semi‐structured interviews with local stakeholders, and a bilingual literature review to assess seagrass meadow trajectories around Itamaracá Island, Brazil. Landsat imagery showed that seagrass cover declined by an estimated 80% between 1990 and 2022, with the most rapid losses between 1990 and 2009. By triangulating multiple evidence sources, we identified 17 interacting drivers, including damaging fishing practices, coastal infrastructure and, unexpectedly, the mechanical removal of seagrasses to feed manatees in rehabilitation programmes. Each factor's temporal and spatial alignment with observed losses was graded as High, Moderate or Low. Although the baseline mapping from 1970 provides important contextual insights, showing an overall loss of approximately 94%, comparisons focus on the methodologically consistent trajectories from 1990 to 2022. Our interdisciplinary approach demonstrates the value of integrating local ecological knowledge and literature‐based evidence from different cultural backgrounds with remote sensing to strengthen causal understanding, synthesise information across disciplines and inform adaptive coastal management. Despite inherent methodological constraints, our findings highlight the importance of collaborative, multilingual research to advance socio‐economically and ecologically informed coastal conservation. Read the free Plain Language Summary for this article on the Journal blog.