Quantifying and mapping global mining impacts on freshwater biodiversity

Mining poses significant threats to freshwater ecosystems, with impacts often enduring long after operations cease. Growing concerns suggest that mining expansion to meet global mineral demands for decarbonization may amplify cumulative risks to freshwater biodiversity. However, the biological magnitude and spatial extent of these impacts remain poorly understood, hampering our ability to meet international conservation targets. We present an integrated global assessment quantifying the severity of biodiversity impacts and mapping priority conservation areas at risk from mining activities.

We synthesize standardized biodiversity data from studies worldwide to quantify mining impacts. Although research has largely focused on terrestrial systems, our results show that freshwater biodiversity is more severely affected, with significant reductions in species richness and abundance. Yet, some taxa persist or even increase in sites affected by mining, largely due to tolerant and generalist species able to exploit disturbed environments. This pattern masks the loss of sensitive taxa and compositional turnover, rather than gain in biodiversity. Freshwater invertebrates show the largest population declines, whereas fishes exhibit greater variability, with higher-trophic taxa declining most as prey availability drops and food-web structures shift. To assess spatial patterns of impact, we applied an aggregated community metric (mean species abundance), revealing that while the intensity of impacts decreases with distance, they remain detectable far downstream.

Considering this downstream propagation, we map the global extent of freshwater biodiversity exposure to mining-related contamination and its overlap with conservation areas. We estimate that around 16% of affected rivers are located within Protected Areas and Key Biodiversity Areas. Although much of the current discourse centres on minerals essential for low-carbon technologies, we find gold and coal mining responsible for the most extensive impacts. Artisanal and small-scale operations are major contributors, likely causing disproportionate impacts due to their frequently unregulated nature.

By integrating quantitative evidence of biodiversity loss with spatial mapping of risk, we provide the first comprehensive global assessment of mining impacts on freshwater biodiversity. Our findings reveal both the most threatened taxonomic groups and conservation sites, highlighting the urgent need for hydrologically informed conservation planning and stronger environmental governance to reconcile mineral demand with global biodiversity goals.