Pechlaner 1984; Sostoa and Lobón-Cerviá 1989). The first introductions in the Alps
were carried out at the end of the sixteenth century (Pechlaner 1984) and in the
Tatra mountains at the end of the nineteenth century (Brancelj 2000; Gliwicz and
Rowan 1984). In the Cantabric mountains (Iberian Peninsula) introductions also
occurred at the end of the nineteenth century (Terrero 1951) and even more recently
in the Sistema Central and Sistema Ibérico, also in the Iberian Peninsula
(Martinez-Solano et al. 2003; Toro et al. 2006). In the Pyrenees, the first fish
introductions took place at least during the middle ages, being the first written
evidence of fish presence from the fourteenth century (Miró 2011).
In conclusion, we know that introduced fish are present in high-altitude aquatic
habitats in many mountain ranges all around the world, but we are not aware of the
exact spatial extent of their distribution (e.g. the percentage and features of stocked
lakes at a regional scale). We also know that except a very few medieval and some
pre-industrial introductions occurred in Europe, the majority of the introductions
started during the nineteenth century and in particular in the second half of the
twentieth. Indeed in the past decades, a critical acceleration of the invasion has been
promoted by different governmental agencies, supporting the growing popularity of
recreational angling (Pister 2001; Schindler and Parker 2002).
8.2 The Process of Species Introductions in the Alps
The first documented fish introductions in the Alps were carried out during the
middle Age, at the end of the sixteenth century, probably during the reign of Kaiser
Maximilian I (Pechlaner 1984). However, similarly to most mountain ranges across
Europe, most of the fish introductions took place in the recent decades to support
recreational angling. In Italy, the phenomenon became particularly evident from the
1960s onwards when, recreational angling became a popular activity (Cantonati
et al. 2006). The presence of introduced species such as Salmo trutta L 1758 or
species from across the Atlantic Ocean, such as Oncorhynchus mykiss (Walbaum
1792) and Salvelinus fontinalis (Mitchill 1814) is common all around the Alps.
Moreover Salvelinus umbla (L 1758) have been introduced across the Italian Alps
(Zerunian 2003). Restocking with S. umbla is considered a conservation measure in
some Alpine regions, even if its status as an indigenous species in Italy has given
rise to serious doubts (Pechlaner 1984; Machino 1999; Piccinini et al. 2004) and the
fact that this species does not require ex situ conservation actions. Also the marble
trout (Salmo marmoratus Cuvier, 1829), an alpine endemism, was sometimes
introduced in alpine lakes, as well as Salvelinus namaycush (Walbaum 1792) from
North America. Finally cyprinids, used as live baits by anglers, are accidentally or
voluntary released in many high-altitude lakes, and minnows (Phoxinus sp.) are
able to establish reproductive populations.
For the Alps, a detailed and coherent history of the fish introductions is not
available: information is often insufficient and still scattered in many archives and
grey literature. Also, the distribution of introduced fish has rarely been assessed
8 Why Should We Preserve Fishless High Mountain Lakes?
183
were carried out at the end of the sixteenth century (Pechlaner 1984) and in the
Tatra mountains at the end of the nineteenth century (Brancelj 2000; Gliwicz and
Rowan 1984). In the Cantabric mountains (Iberian Peninsula) introductions also
occurred at the end of the nineteenth century (Terrero 1951) and even more recently
in the Sistema Central and Sistema Ibérico, also in the Iberian Peninsula
(Martinez-Solano et al. 2003; Toro et al. 2006). In the Pyrenees, the first fish
introductions took place at least during the middle ages, being the first written
evidence of fish presence from the fourteenth century (Miró 2011).
In conclusion, we know that introduced fish are present in high-altitude aquatic
habitats in many mountain ranges all around the world, but we are not aware of the
exact spatial extent of their distribution (e.g. the percentage and features of stocked
lakes at a regional scale). We also know that except a very few medieval and some
pre-industrial introductions occurred in Europe, the majority of the introductions
started during the nineteenth century and in particular in the second half of the
twentieth. Indeed in the past decades, a critical acceleration of the invasion has been
promoted by different governmental agencies, supporting the growing popularity of
recreational angling (Pister 2001; Schindler and Parker 2002).
8.2 The Process of Species Introductions in the Alps
The first documented fish introductions in the Alps were carried out during the
middle Age, at the end of the sixteenth century, probably during the reign of Kaiser
Maximilian I (Pechlaner 1984). However, similarly to most mountain ranges across
Europe, most of the fish introductions took place in the recent decades to support
recreational angling. In Italy, the phenomenon became particularly evident from the
1960s onwards when, recreational angling became a popular activity (Cantonati
et al. 2006). The presence of introduced species such as Salmo trutta L 1758 or
species from across the Atlantic Ocean, such as Oncorhynchus mykiss (Walbaum
1792) and Salvelinus fontinalis (Mitchill 1814) is common all around the Alps.
Moreover Salvelinus umbla (L 1758) have been introduced across the Italian Alps
(Zerunian 2003). Restocking with S. umbla is considered a conservation measure in
some Alpine regions, even if its status as an indigenous species in Italy has given
rise to serious doubts (Pechlaner 1984; Machino 1999; Piccinini et al. 2004) and the
fact that this species does not require ex situ conservation actions. Also the marble
trout (Salmo marmoratus Cuvier, 1829), an alpine endemism, was sometimes
introduced in alpine lakes, as well as Salvelinus namaycush (Walbaum 1792) from
North America. Finally cyprinids, used as live baits by anglers, are accidentally or
voluntary released in many high-altitude lakes, and minnows (Phoxinus sp.) are
able to establish reproductive populations.
For the Alps, a detailed and coherent history of the fish introductions is not
available: information is often insufficient and still scattered in many archives and
grey literature. Also, the distribution of introduced fish has rarely been assessed
8 Why Should We Preserve Fishless High Mountain Lakes?
183