Water-related ecosystem services of lakes worldwide: a comprehensive meta-analysis

Lakes provide water-related -also known- as blue ecosystem services (BES), which maintain biodiversity, regulate hydrological and biogeochemical processes, and support human livelihoods. To assess the state of knowledge on lakes’ BES, we conducted a meta-analysis of 250 peer-reviewed articles selected from an initial screening of 1,910. We found that studies on lakes’ BES have grown steadily but remain geographically biased toward Europe, Asia (China), and North America, reflecting both lake abundance and high research potential in the Northern Hemisphere. This imbalance leaves knowledge gaps of lakes’ BES in Africa, South America, and Oceania, regions where communities are dependent on freshwater resources for livelihoods. The studies analyzed here generally cover different settings, from lowlands to highlands. We found that small lakes were the most studied due to their abundance. Overall, 19 types of lake BES were identified. Biodiversity maintenance and nutrient-cycle were the most studied BES, followed by tourism and recreation, and water storage (irrigation, food and raw-material supply). In contrast, the role of lakes for hydrological and climate regulation, pollutant dilution, drinking water, and educational and symbolic values remains understudied. Commonly studied pressures on lakes’ BES included invasive and exotic species, nutrient alterations, and disruptions to water source connectivity, primarily impacting habitats, water quality, and food production. Management responses are policies and programs for water sustainability implemented beyond lake boundaries, hard infrastructure that prioritizes direct human benefits, and nature-based solutions that enhance habitats and water quality. Future research must integrate ecological, hydrological, and social connectivity of lakes, while addressing trade-offs and synergies among BES under increasing human pressures and climate change. Achieving this will require coordinated, large-scale, long-term monitoring supported by transdisciplinary collaboration.