Innovating community fish refuges in Tonle Sap Lake for enhancing resilience to climate change and the altered hydrological regime of the Mekong River

• Mekong River, Tonle Sap Lake and its tributaries are interconnected and sustained the productivity of the ecosystems. • Climate change, and infrastructure and hydropower development have altered the flood pulse and hydrological flow of the Mekong River, Tonle Sap Lake and tributaries. • Community Fish Refuges (CFRs) restore lateral connectivity between Tonle Sap Lake, floodplains, and rice-field ecosystems, rebalancing landscape–waterscape fluxes under climate and hydrological stress. • CFRs are sources of water for fishery, agriculture and domestic water use, and it provides foods to sustained local communities. River ecosystem discontinuity and connection are of concern in transboundary river basins. Humans have impacted river ecosystems and disconnected the river ecosystem landscapes by building infrastructure and hydropower. Climate change has decreased connectivity. A bulk of studies examine the impacts of climate change and infrastructure development on fragmented river systems, and only a few examine how humans can address these impacts and restore the connectivity of river systems resilient to climate change and hydropower effects. Thus, our study examines 140 community fish refuges (CFRs) in Tonle Sap Lake in restoring river landscape connectivity and building resilient aquatic ecosystems to climate change and changing hydrological regimes. We conclude that the CFR system reconnects the lake tributaries, lake, floodplains, and rice fields. Most CFRs do not dry up in the dry season, providing habitats for fisheries and water for rice fields, increasing fishery and rice farming productivity in waterbodies, floodplains, and rice fields, and improving the livelihoods of local communities.