IMIS

The inventory is the result of the study Boets et al. (2016) (https://doi.org/10.3391/ai.2016.11.2.03 with occurrence data at https://doi.org/10.15468/xjtfoo) where it was originally published as supplementary material. Here it is published as a standardized Darwin Core Archive and includes for each species: the scientific name, higher classification, and stable taxon identifier (in the taxon core), the year of first introduction and last assessment in Flanders (given as a year range in the event date in the distribution extension), coarse habitat information (in the species profile extension) and the pathway(s) of introduction, native range(s), and invasion stage in Flanders (in the description extension). The dataset can be used for researching and managing aquatic invasions or compiling regional and national registries of alien species. Issues with the dataset can be reported at: https://github.com/trias-project/alien-macroinvertebrates. This checklist covers alien macroinvertebrate species found in different aquatic habitats in Flanders (northern Belgium), including all types of waterways, lakes, and coastal habitats. The proximity to the sea, the interconnection of different waterways, the high degree of canalisation, and the presence of several harbours make Flemish watercourses susceptible to aquatic invasions (Boets et al. 2016).
In total, 73 alien macroinvertebrate species have been collected in Flanders of which 52 are regularly encountered in fresh and/or slightly brackish waters. The remaining 21 species are restricted to the marine environment for at least a considerable share of their lifetime. Most alien macroinvertebrate species are crustaceans (51%), followed by Mollusca (27%), Annelida (19%) and Platyhelminthes (3%). Most alien macroinvertebrates originate from North America (37%) or the Ponto-Caspian region (21%). The main vector of introduction is probably passive transport via the hull of ships (biofouling) and ballast water (71%). The transport via canals is the second main vector (28%) and promoted the dispersion of alien macroinvertebrates. Also, some species were introduced through aquaculture (17%) and hobbyists (6%) (Boets et al. 2016).