Belgian private quarries explored by scuba divers are often inhabited by numerous exotic species, most of which have been intentionally introduced. For example, crayfish are prized for their decorative value and can be present in large numbers. However, they often cause problems by disturbing the natural balance of ecosystems.
In 2023, the municipality of Middelkerke (Belgium) drained an entire pond in order to eradicate a population of the marble crayfish (Procambarus virginalis), a species with a high invasive potential because of its reproductive system by parthenogenesis. Such measures are also needed in other locations, as various exotic crayfish are wreaking havoc in Belgian water bodies.
Want to know more? BopCo member Brigitte Segers wrote an article about it.
Read it here:
In French, p. 40 – 43
https://issuu.com/lifras/docs/hippo_269_final_site
In Dutch, p. 6 – 8
https://leden.nelos.be/api2/app/bestand/7748/Hippocampus299(21.50MB).pdf
In conclusion, the introduction of such exotic species is never without consequences for the natural balance of water bodies.
Stay vigilent and report your observations of exotic species to RIPARIAS.