The information comes from European Union Strategy on Invasive Species.
Invasive species is an alien species (non-native) with a significant ability to expansion, which is spread naturally or thanks to anthropogenic impact and is a threat to flora and fauna of the ecosystem, competing with native species for ecological niche, as well as contributing to the extinction of native species.
This is the species, which introduction into the environment or spread may threaten ecological diversity or involve other unforeseen consequences.
Invasive species are second, after the destruction of habitats, the greatest threat to global biodiversity.
Among the most dangerous invasive species in Poland are:
● Raccoon dog
● American mink
● Common raccoon
● Fishhook waterflea
● Zebra mussel
● Signal crayfish
● Orconectes limosus
● Nile perch
● Western corn rootworm
● Chinese mitten crab
● Dwarf crab (Rhithropanopeus harrisii)
The impact of invasive species on ecology:
Invasive species are considered to be one of the greatest threats to biodiversity. Their impact on the local environment includes:
● competition with native organisms for food and habitat (e.g., in many areas of Europe coming from America Gray squirrel displaces native Red squirrel)
● changing the structure of the ecosystem (e.g., big area of the Mediterranean seacoast was dominated by monocultures of algae Caulerpa taxi folia)
● hybridization with native species
● most invasive species are the reservoir of parasites and are carriers of pathogens (e.g., Common raccoon)
The economic and legal aspects
At the moment the EU does not have any legal instrument for dealing with invasive species even though they are a significant risk to the economy of the EU. The annual cost of damage caused by invasive species and the costs of control measures needed have been estimated at at least 12 billion euro.
There is no formal requirement for systemic risk-analysis when introducing a non-native species that may have an impact on biodiversity. Unintentional introduction of such species to the environment is not regulated at the level of EU countries and the whole community. There is no consistent European monitoring and control system of invasive species and their impact on biodiversity.