Science Facing Aliens - Invasive Alien Species in Belgium - Belgian ...

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Status of non-indigenous fish species in Flanders
Louette et al. (2001) found evidence in the literature of 47 considered, attempted or successful
introductions of fishes in Belgium since 1800; of these, 23 were partially successful (i.e.
recorded in public waters after introduction or known to be reproducing).
Since 1990 at least 18 non-native freshwater fish species were reported during fish stock
assessments by INBO, Agency for Nature and Forest (ANB) and several universities in
Flanders. Nine species are naturalised and maintain self-sustaining populations while nine are
acclimatised only. Two of these acclimatised species however occur exclusively near cooling
water discharges of power plants. These non-native species constitute more than 35 % of the
total number of freshwater fish species in Flanders. Most species originate from Asia and N.
America, with seven and six species respectively, three species come from Eastern Europe
and two from Africa. Nine species were introduced pre-1950s and nine species since then.
These 18 species are listed in table 1.
To illustrate that non-indigenous fish species are not a localised phenomenon, table 2
shows the distribution over the 11 Flemish river basins. Four species occur in all river basins,
and one in all but one. Seven species occur in one basin only and the other six were found in
Table 1: Species and common names of the 18 non-indigenous freshwater fishes occurring in
Flanders, with their continent of origin (AS, Asia; EE, Eastern Europe; AFR, Africa; NA, North
America), suspected pathways (AQ, aquaculture; OR, ornamental; AN, angling or bait fish; BC,
biological control; UN, unintentional), date of introduction (year or period; c., century) and current
status (Copp et al., 2005b; A, acclimatized; N, naturalized; A*, acclimatized only in restricted areas at
cooling water discharges of power plants).
Latin name Common name Origin Introduction Pathway(s) Status
Acipenser baeri Siberian sturgeon AS 1990s AQ, OR A
Ameiurus nebulosus Brown bullhead NA 1871 AQ, OR N
Aspius aspius Asp EE 1984 AN N
Carassius auratus Goldfish AS 17th c. OR A
Carassius gibelio Gibel carp AS or EE 17th c. UN N
Clarias gariepinus African catfish AFR 1980s AQ A*
Ctenopharyngodon
idella
Grass carp AS 1967 BC A
Cyprinus carpio Common carp EE 13th c. AQ N
Hypophthalmichthys
molitrix
Silver carp AS 1975 BC A
Hypophthalmichthys
Bighead carp AS 1975 BC A
nobilis
Ictalurus punctatus Channel catfish NA 1884 AQ A
Lepomis gibbosus Pumpkinseed NA 1885 OR N
Oncorhynchus mykiss Rainbow trout NA 1884 AQ, AN A
Oreochromis niloticus Nile tilapia AFR 1990 AQ A*
Pimephales promelas Fathead minnow NA 1984 AN N
Pseudorasbora parva Topmouth gudgeon AS 1992 UN, AN N
Sander lucioperca Pikeperch EE 1890 AN N
Umbra pygmaea
Eastern
mudminnow
NA 1920 OR, AQ N