complemented with electrofishing (Pacas and Taylor 2015), and in one case with
local fishermen (Tiberti et al. 2016a). Piscicides (e.g. rotenone and antimycin) have
also been used to eradicate fish (e.g. Sanni and Wærvågen 1998; Gresswell 1991).
However, their use has ecological effects on native fauna such as invertebrates (e.g.
Dalu et al. 2015; Kjærstad and Arnekleiv 2011), and legal and social complications,
especially in protected areas because the very notion of a protected area implies that
it remains chemical free. It is important to highlight that eradication actions are a
“second step”, which should come when protection measures (fishing ban and the
prohibition of fish stocking) are already in place and effectively enforced; if these
fundamental guarantees are absent or weak, the local context (i.e. concrete risk of
sabotage of the conservation actions) might suggest deferring the project to future
times.
The most ambitious projects have been carried out in North America both USA
and Canada (e.g. Knapp and Matthews 1998; Parker et al. 2001; Vredenburg 2004;
Knapp et al. 2007; Pacas and Taylor 2015). In Europe, removal of brook trout has
also been achieved in a small alpine lake in the central Iberian Peninsula (Toro et al.
2006). Furthermore, two recent European Commission funded projects, the LIFE+
Bioaquae (www.bioaquae.eu) and LIFE+ LimnoPirineus (www.lifelimnopirineus.
eu) are removing fish from different high mountain lakes. The former started
removing brook trout from four lakes and their surrounding streams of the Gran
Paradiso National Park (Italian Alps) in 2013 (Tiberti et al. 2013), having already
removed fish from all lakes (R. Tiberti, Pers. Comm.). The latter started at 2015 in
the Pyrenees (Aigüestortes i Estany de Sant Maurici National Park and Alt Pirineu
Natural Park) and is aiming at removing brook trout, rainbow trout, brown trout and
European minnow from eight lakes and their surrounding streams. Three of them
have minnow only, two both minnow and brown trout, two brook trout and one
rainbow trout.
Studies of the recovery of restored lakes have shown the relatively fast recovery
of lake populations when surrounding refugees are available (Knapp et al. 2001b,
2005, 2007; Sarnelle and Knapp 2004), being amphibians and macroinvertebrates
those with faster recovery (Knapp et al. 2001b, 2005, 2007), and crustacean zooplankton the later (Knapp and Sarnelle 2008). These latter authors have also shown
that some species producing resistance eggs are not able to survive for many years
in the egg bank (e.g. calanoid copepods). Fish residence times (years that fish have
been in the lake) above ca. 50 years greatly reduce the fast recovery of these
species from the egg bank.
Acknowledgements The authors would like to acknowledge those people that provided information about fish introductions, two anonymous reviewers and the editors for giving us the
opportunity to participate in the workshop and writing this paper. This book chapter is a joint
contribution of the LIFE+ projects BIOAQUAE (Biodiversity Improvement of Aquatic Alpine
Ecosystems, LIFE11 BIOIT000020) and LIMNOPIRINEUS (Restoration of lentic habitats and
aquatic species of Community interest in high mountains of the Pyrenees, LIFE13
NAT/ES/001210). RT thanks the University of Pavia and Bruno Bassano and Giuseppe Bogliani
for their support. DB benefitted from a scholarship from Government of Ecuador (SENESCYT
20090187-20130946) and IS from a Catalan Government grant (2015 FI_B 01147).
198
M. Ventura et al.
local fishermen (Tiberti et al. 2016a). Piscicides (e.g. rotenone and antimycin) have
also been used to eradicate fish (e.g. Sanni and Wærvågen 1998; Gresswell 1991).
However, their use has ecological effects on native fauna such as invertebrates (e.g.
Dalu et al. 2015; Kjærstad and Arnekleiv 2011), and legal and social complications,
especially in protected areas because the very notion of a protected area implies that
it remains chemical free. It is important to highlight that eradication actions are a
“second step”, which should come when protection measures (fishing ban and the
prohibition of fish stocking) are already in place and effectively enforced; if these
fundamental guarantees are absent or weak, the local context (i.e. concrete risk of
sabotage of the conservation actions) might suggest deferring the project to future
times.
The most ambitious projects have been carried out in North America both USA
and Canada (e.g. Knapp and Matthews 1998; Parker et al. 2001; Vredenburg 2004;
Knapp et al. 2007; Pacas and Taylor 2015). In Europe, removal of brook trout has
also been achieved in a small alpine lake in the central Iberian Peninsula (Toro et al.
2006). Furthermore, two recent European Commission funded projects, the LIFE+
Bioaquae (www.bioaquae.eu) and LIFE+ LimnoPirineus (www.lifelimnopirineus.
eu) are removing fish from different high mountain lakes. The former started
removing brook trout from four lakes and their surrounding streams of the Gran
Paradiso National Park (Italian Alps) in 2013 (Tiberti et al. 2013), having already
removed fish from all lakes (R. Tiberti, Pers. Comm.). The latter started at 2015 in
the Pyrenees (Aigüestortes i Estany de Sant Maurici National Park and Alt Pirineu
Natural Park) and is aiming at removing brook trout, rainbow trout, brown trout and
European minnow from eight lakes and their surrounding streams. Three of them
have minnow only, two both minnow and brown trout, two brook trout and one
rainbow trout.
Studies of the recovery of restored lakes have shown the relatively fast recovery
of lake populations when surrounding refugees are available (Knapp et al. 2001b,
2005, 2007; Sarnelle and Knapp 2004), being amphibians and macroinvertebrates
those with faster recovery (Knapp et al. 2001b, 2005, 2007), and crustacean zooplankton the later (Knapp and Sarnelle 2008). These latter authors have also shown
that some species producing resistance eggs are not able to survive for many years
in the egg bank (e.g. calanoid copepods). Fish residence times (years that fish have
been in the lake) above ca. 50 years greatly reduce the fast recovery of these
species from the egg bank.
Acknowledgements The authors would like to acknowledge those people that provided information about fish introductions, two anonymous reviewers and the editors for giving us the
opportunity to participate in the workshop and writing this paper. This book chapter is a joint
contribution of the LIFE+ projects BIOAQUAE (Biodiversity Improvement of Aquatic Alpine
Ecosystems, LIFE11 BIOIT000020) and LIMNOPIRINEUS (Restoration of lentic habitats and
aquatic species of Community interest in high mountains of the Pyrenees, LIFE13
NAT/ES/001210). RT thanks the University of Pavia and Bruno Bassano and Giuseppe Bogliani
for their support. DB benefitted from a scholarship from Government of Ecuador (SENESCYT
20090187-20130946) and IS from a Catalan Government grant (2015 FI_B 01147).
198
M. Ventura et al.