The old and the new on threats to high-mountain lakes in the Alps: A comprehensive examination with future research directions

The high-mountain lakes of the Alps, perched like glistening gems in the cradle of Europe’s most formidable mountain range, have for generations epitomized nature’s majesty. These remote and pristine bodies of water have served as invaluable sentinels of global change, repositories of geological history, and sources of freshwater for the surrounding regions. Yet, despite their seemingly imperturbable beauty and seclusion, these high- mountain lakes are not immune to the evolving forces of our changing world. Re-emerging threats, exacerbated by the relentless march of climate change and intensified human activities, cast a shadow over their future, posing profound challenges that demand our attention. The aim of this perspective is to shed light on the main emerging threats, raise awareness, and advocate for proactive actions aimed at preserving and protecting high- mountain lakes. These threats include climate change, retreat of glaciers, UV radiation, long-range transport of contaminants, impact of alien species and water usage for Alpine storage power stations. Additionally, increased tourism and recreational activities in these pristine environments can cause habitat disturbance, further endangering these unique ecosystems. The present perspective article also offers valuable perspectives on the necessity of monitoring and research efforts in high-mountain lakes. Such actions are crucial for comprehending the ecological well-being of these ecosystems, evaluating the consequences of environmental shifts, and devising successful conservation strategies.