Dysbiosis in mountain lakes and their health-related consequences.

DYHARD will tackle the growing threat of ecosystem degradation in mountain lakes, driven by the likely decline of key microbial species and their ecological functions driven by global changes. Microbes living in lake biofilms are essential for critical ecosystem services such as nutrient cycling, organic matter breakdown, water purification, and pollutant removal. These services are vital not only for ecosystem health and biodiversity, but also for human well-being—particularly since mountain lakes provide drinking water to 25% of Europe’s population—and for economic sectors that rely on water quality, such as tourism, pastoralism, and farming. The loss of these keystone microbes could lead to cascading effects, including a decline in water quality, reduced ecosystem resilience, as well as health and economic consequences. DYHARD aims to anticipate and reduce these risks by identifying the microbial taxa that play a central role in maintaining ecosystem balance and tracking how they respond to environmental pressures such as pollution and climate change. To do this, DYHARD will combine cutting-edge tools—including deep learning models and metagenomic data—to analyse how microbial communities evolve over time and to simulate the impacts of keystone species loss. DYHARD will also assess the functional roles of these microbes by linking their genetic material to key ecological processes, such as nitrogen cycling or contaminant degradation, helping identify the most vulnerable and irreplaceable functions. The project will propose indicators and monitoring tools to detect early warning signs of microbial and functional decline. It will also recommend science-based conservation and restoration strategies tailored to mountain lake ecosystems. By bridging microbial ecology, environmental management, and stakeholder engagement, DYHARD will help safeguard the ecological integrity and socio-economic value of mountain lakes facing increasing anthropogenic pressure.