Inventory of alien macroinvertebrates in Flanders, Belgium

Study Extent

See Boets et al. (2016).

Sampling

See Boets et al. (2016).

Quality Control

See step description.

Method steps

1. The source data for this standardized checklist is an Excel spreadsheet, originally published as Table S1 in the supplementary material of Boets et al. (2016) (http://www.aquaticinvasions.net/2016/Supplements/AI_2016_Boets_etal_Supplement.xls).
2. This raw data file was reformatted to make it more machine-readable and uploaded to a GitHub repository (https://github.com/trias-project/alien-macroinvertebrates). See https://trias-project.github.io/alien-macroinvertebrates for an introduction to this repository and the mapping of this dataset.
3. The source references for each taxon were also standardized and uploaded.
4. We developed a RMarkdown script to document and perform the transformation of the data to Darwin Core, which includes the following steps:
5. Perform some basic data cleaning of the raw data.
6. Generate stable and unique identifiers for each taxon (taxonID).
7. Create a taxon core file (http://rs.gbif.org/core/dwc_taxon.xml).
8. Create a distribution extension file (http://rs.gbif.org/extension/gbif/1.0/distribution.xml), including standardization of the distribution date range.
9. Create a species profile extension file (http://rs.gbif.org/extension/gbif/1.0/speciesprofile.xml), with coarse habitat information.
10. Create a description extension file (http://rs.gbif.org/extension/gbif/1.0/description.xml), with standardized pathway of introduction (using the pathway vocabulary from the Convention on Biological Diversity (2014)), native range (using the WGSRPD vocabulary from Brummitt (2001) where applicable), and invasion stage (set as “established” based on Blackburn et al. (2011)).
11. The resulting Darwin Core data files are uploaded to the INBO IPT and documented with metadata.
12. The dataset is published and registered with GBIF.

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).

1. Animalia
   common name: animals rank: kingdom
2. Annelida
   rank: phylum
3. Arthropoda
   rank: phylum
4. Mollusca
   rank: phylum
5. Platyhelminthes
   rank: phylum

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).