Current protected areas provide limited benefits for Mekong fish biodiversity

Current protected areas provide limited benefits for Mekong fish biodiversity | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Current protected areas provide limited benefits for Mekong fish biodiversity Jingrui Sun, Yushan Tang, Damiano Baldan, Shams Galib, Phillip Haubrock, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9610239/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Freshwater protected areas (PAs) are central to global biodiversity targets, yet their effectiveness in river networks depends not only on spatial extent but also on whether they capture connected habitats and migration corridors. This issue is particularly important in the Mekong Basin, a global freshwater biodiversity hotspot. Here, we provide a basin-wide assessment of how the existing PA network aligns with fish biodiversity, major habitat types, and longitudinal connectivity. At the subcatchment-scale, we quantified PA coverage across river orders and assessed within-subcatchment connectivity. At the catchment scale, we evaluated species-level protection coverage (SPC) and the alignment between species’ longitudinal connectivity needs and the spatial arrangement of PAs (ΔPCI). Although PAs cover 21% of total river length, protection is highly uneven across ecological regions, whereas biodiversity-rich lowland mainstem remained weakly protected. PA coverage was moderately associated with river connectivity, indicating limited spatial alignment between protection and functional connectivity. SPC and ΔPCI remained low for most species, with amphidromous fishes receiving least protection. Our findings suggest that area-based protection targets alone are insufficient for riverine biodiversity conservation unless protection is explicitly distributed across longitudinally-connected river sections. Effective freshwater conservation in the Mekong will require river-network-based planning, connectivity restoration, and stronger transboundary coordination. Biological sciences/Ecology/Freshwater ecology Biological sciences/Ecology/Conservation biology Biological sciences/Ecology/Animal migration Earth and environmental sciences/Environmental sciences/Environmental impact Kunming–Montreal Global Biodiversity Framework river connectivity biodiversity conservation freshwater fish habitat fragmentation Full Text Additional Declarations There is NO Competing Interest. Supplementary Files SupplementaryData1.xlsx SUPPLEMENTARY DATA SET 1 SupplementaryData2.xlsx SUPPLEMENTARY DATA SET 2 Appendix.docx SUPPLEMENTARY INFORMATION Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9610239","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":634603793,"identity":"3c82e2c7-da73-480e-a69e-440bd80b68bf","order_by":0,"name":"Jingrui 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