Project description

Mountain ecosystems worldwide face multiple threats arising from global change and its interactions with socio-cultural, economic and political developments. Together, these factors impact on the ability of mountains to support the livelihoods of more than 50% of the human population with essential ecosystem services.

Based on past and current observations, as well as climate projections, aquatic mountain ecosystems are particularly vulnerable and at risk. In light of their roles as major water reservoirs for humankind and as biodiversity hotspots in generally sparse high-altitude landscapes, this is a major concern.

Besides climate change, fish stocking of naturally fishless lakes has been identified as particularly detrimental to water quality and biodiversity. Due to the magnitude of the ecological impact and to the global extent of fish introductions into mountain lakes, introduced fish are perhaps the most important threat to mountain lake biodiversity, ecosystem functioning and water quality.

This threat is particularly important as fish introductions co-occur with a number of other anthropogenic activities such as human population growth, changing economic activities, land-use change, urbanization, pollution, loss and degradation of aquatic habitats, overexploitation, flow modifications and alien species invasions.

Together and in interaction with climate change, these factors accelerate and exacerbate the environmental and ecological degradation of mountain aquatic ecosystems and the loss of unique species and life forms. Yet, despite strong concerns over the long-term health and functioning of aquatic ecosystems, experimental and restoration studies that link fish stocking to pollution, aquatic disease ecology, and ecosystem health, are still scarce.

1. What are the socio-economic, cultural, and environmental drivers for fish stocking in mountain lakes?

2. What is the impact of fish stocking and which are the future social and ecological trajectories of the ongoing invasion process under climate and global change scenarios?

3. How can the detrimental effects of fish introductions be mitigated, while minimizing the impact on the livelihood and well-being of local human populations?