Fish passage across Southeast Asia: key informant insights into motivations and triggers for water resource planning and policymaking

Southeast Asia’s inland fisheries are under threat from extensive irrigation and hydropower development. Of particular concern is the Mekong River, which is currently home to the world’s most productive inland fishery. To minimise these negative impacts, fish-friendly infrastructure can be incorporated into these barriers to facilitate fish migration or “passage.” However, historically fishways have often been overlooked given cost considerations and a lack of awareness of benefits across irrigation managers and funding bodies. This study aimed to understand fishway implementation decision-making across the Mekong. Findings from 19 interviews showed that funding was central to decision-making and acted as an ability and a trigger, to both positively and negatively influence stakeholders’ motivations for fishway implementation. Masterclasses were viewed as key vehicles for building technical capacity and consent within the region through the creation of networks and social capital between irrigation engineers and fisheries staff, as well as the development of “champions.”