Invasive alien species in Switzerland - Schweizer ...

An inventory of alien species and their threat to biodiversity and economy in Switzerland FOEN 2006 60
Fig. 2.1 > Numbers of native and introduced fish species in different families in Switzerland.
Salmonidae
Thymallidae
Coregonidae
Esocidae
Cottidae
Percidae
Gobiidae
Centrarchidae
Blenniidae
Gasterosteidae
Gadidae
Siluridae
Ictaluridae
Cyprinidae
Cobitidae
Balitoridae
Clupeidae
Anguillidae
0 5 10 15 20 25 30 35
No. species
Tab. 2.6 > Total number of members of five fish families worldwide and the number of species
in these families introduced into Switzerland.
Total no. species per
family
No. species introduced to
Switzerland
Native
Introduced
Percentage of introduced to total
number [%]
Cyprinidae 2000 8 0.4
Ictaluridae 35 1 2.9
Centrarchidae 30 2 6.7
Percidae 159 1 0.6
Salmonidae 66 3 4.5
The lack of certainty about which species are actually established, and which of these
are invasive, combined with the different definitions used in national reports, which
leads to anomalies regarding which species are listed and how they are categorized,
makes a comparison with other European countries such as Austria and Germany
difficult. However, the situation appears to be very similar, with the exception of
species from Central Europe which are native to Germany. As discussed above, many
species are of North American and Asian origin and were widely introduced to Europe,
so that they occur also in neighbouring countries.
The 15 introduced species represent about 25 % of the current fish fauna. This value is
fairly high compared with the figures for the other groups of vertebrates, in which
introduced species form less than 10 % of the Swiss fauna. This reflects the economic
importance of fish species, but also indicates the potential threat to native biodiversity.