As of the end of 2008, 25 species of non-native fishes have been documented in the Republic of Belarus. Of these, 17 (68%) species were deliberately introduced for aquaculture, six (24%) species invaded from the adjacent territories by natural dispersal, and two (8%) species were likely introduced accidentally. During the 20th century, the number of non-native fishes in Belarus increased exponentially, resulting in significant shifts in taxonomic composition of the country’s ichthyofauna. For the first time, we assessed the invasive potential of the introduced fishes by applying a uniform protocol, the Fish Invasiveness Screening Kit (FISK). Based on the total FISK scores, all the non-native fishes in Belarus were classified into two groups: high and medium risk of becoming invasive. In terms of the economic sectors at risk (‘aquacultural/fisheries’, ‘environmental’, and ‘nuisance’), all species were classified into three distinct groups. The highest risk to all of these sectors wa s posed by the brown bullhead Ameiurus nebulosus Le Sueur, 1819, gibel carp Carassius gibelio (Bloch, 1782), round goby Neogobius melanostomus (Pallas, 1814), Amur sleeper Perccottus glenii Dybowski, 1877, and topmouth gudgeon Pseudorasbora parva (Temminck & Schlegel, 1846). The two risk categories identified in the present study can be used in prioritizing the resources for the management of non-native fish species of Belarus and in countries with similar environmental conditions.
Aquatic Invasions (2010) 5(1): 101-114

The assessment of risks associated with alien invasive organisms implies a detailed knowledge of their taxonomical composition and distribution within an assessment unit. In this paper we used both literature data and results from our field surveys of more than forty sites, conducted in 2006-2008, to compile a checklist of aquatic alien species (invertebrates and fish) established in the three large river basins of Belarus (Dnieper, Pripyat, Neman). Thirty six alien species have been revealed, most of which are of Ponto-Caspian origin. The discovery of several new species during our surveys indicates that the rate of introductions has substantially increased over the last two decades.
Aquatic Invasions (2009) Volume 4, Issue 2: 337-347