Past, current, and future of the central European corridor for aquatic invasions in Belarus

We analyzed the role of the waterways of Belarus in the spread of aquatic exotic invertebrates through the central European invasion corridor. Present day Belarus became critically important when in the end of the 18th--beginning of the 19th century three interbasin canals connecting rivers from the Black and Baltic seas basins were constructed for international trade. These canals became important pathways facilitating the spread of aquatic alien species. For more than a hundred years, only Ponto-Caspian species colonized Belarus using ships and especially timber in rafts exported by Russia into Western Europe. In the second half of the 20th century, new vectors of spread appeared in Belarus, such as stocking of economically important invertebrates and accidental introductions. This paper is the first comprehensive review of aquatic exotic invertebrates in Belarus. Currently, 19 exotic aquatic invertebrates are known in Belarus, including 14 species of Ponto-Caspian origin. The rate of spread of aquatic invasive species in the second half of the 20th century increased 7-fold compared to the 19th--beginning of the 20th century. We found a significant positive correlation between the time since initial invasion and number of waterbodies colonized. We predict a further increase in the rate of colonization of Belarus by exotic invertebrates as well as an increase in the diversity of vectors of spread and donor areas of alien species, especially when the ongoing reconstruction of the interbasin canals will be completed and the hydrological connection between Black Sea and Baltic Sea basins will be reestablished after an interruption that has lasted for almost a century.