Preliminary studies on fish capture techniques in Gran Paradiso alpine lakes: towards an eradication plan

Abstract

The Gran Paradiso National Park (GPNP) has recently approved an eradication plan, financed within the LIFE+ project BIOAQUAE (Biodiversity Improvement of Aquatic Alpine Ecosystems), to restore some mountain lakes impacted by the introduction of brook trout (Salvelinus fontinalis). This extensive eradication project involves the use of intensive gill netting as a non-invasive conservation measure. The aim of this study is to support, with technical data, the choice of the capture devices needed for the eradication program and to discuss some technical and practical aspects associated with the use of different nets. To this purpose we compared the efficiency, the size selectivity and the induced mortality of three kinds of nets: a trammel and two different multi-mesh gill nets, sampling brook trout in 7 alpine lakes in GPNP. The obtained results allowed us to better define the technical features of the capture devices needed to eradicate brook trout and provide several sugges- tions on how to conduct the eradication campaign.