The introduction of fish into originally fishless high-mountain lakes can strongly alter aquatic food webs. Littoral aquatic macroinvertebrates are heavily preyed upon by fish, yet they also represent an important food resource for several terrestrial and semi-aquatic insectivorous species, including the unique diving passerine, the white-throated dipper ( Cinclus cinclus ). We tested whether competition for this shared resour...

The European Fish Index EFI+ is the only fish-based multimetric index for the assessment of the ecological status of running waters that is validated and thus applicable across most countries of the European Union. Metrics of the index rely on several attributes of the species present in the fish assemblage, irrespective of their native/alien status. The abundance of alien fish, together with other anthropogenic impacts, is on...

Small fish species such as minnows ( Phoxinus sp.) are introduced into mountain lakes by anglers that use them as live bait for fishing salmonids that were previously introduced in these naturally fishless habitats. Introduced fish severely impact native biota but minnows are nevertheless released believing to provide forage for game fish, i.e., salmonids. However, our results indicate that minnows negatively interact with gam...