Participatory approaches in aquatic ecosystem services valuation: insights from a systematic literature review and future research perspectives

• Systematically reviews participatory valuation of aquatic ecosystem services. • Shows how diverse methods and engagement levels affect valuation quality and legitimacy. • Reveals gender and power dynamics shaping valuation and management outcomes. • Demonstrates how citizen science builds trust and local ownership in aquatic ES valuation. • Offers practical guidance for context-specific participatory valuation frameworks. Aquatic ecosystems provide a wide range of essential services, from biodiversity conservation to climate regulation, and are vital to human well-being. However, they face significant threats from intensive human activity and climate change. This paper aims to explore the role of participatory approaches in enhancing the valuation of aquatic ecosystem services (ES) through a systematic literature review. We examine how the engagement of various stakeholders in the knowledge co-production process contributes to more comprehensive and context-specific valuations of aquatic ecosystem services. Findings show that there is no universally accepted effective participatory method, as the success of these approaches largely depends on social, cultural, and geographic contexts. Additionally, the research highlights the need for clear communication, trust-building, and a shared understanding of ES values among stakeholders to address challenges in ecosystem management. While participatory processes foster greater inclusion of local stakeholders, particularly in developing countries, cross-border aquatic ecosystems require systematic valuation frameworks to ensure sustainable management. This study contributes to the ongoing discourse on ecosystem services valuation by encouraging participatory approaches to foster aquatic ecosystem conservation and sustainable management. It further outlines the diversity of participatory approaches identified in the literature, detailing the methods of stakeholder engagement and varying levels of participation that influence the quality and inclusiveness of ecosystem service valuation processes.