In Europe, mammals, fish, insects, and plants in particular have become invasive species. They reproduce, spread, and can endanger native species. Invasive species can, for example, compete with native species for habitat and resources and displace them, transmit diseases, or alter the gene pool by interbreeding with native species. Some invasive species also pose a threat to our health, as they cause allergies and skin diseases. The estimated damage to the European Union's economy runs into the billions every year.

In view of the predicted global warming, an increased spread of alien species and thus an increased risk from invasive species is to be expected. Once established, they are difficult to control.

There are 29 species on the EU list in Rhineland-Palatinate. As a rule, they are not found throughout the entire region, and in some cases their presence is assumed without having been specifically sighted. We would like to briefly introduce a few species to you. A detailed list can be found in the brochure "Invasive Species" in the list of links.

• Glandular impatiens
  This annual plant was introduced as an ornamental plant and has spread throughout Rhineland-Palatinate. It forms mass populations along waterways and in wetlands, displacing native species.
• Ailanthus
  It was introduced because of its resistance to pollution and planted as a street tree and for greening settlements. It can migrate into more natural habitats. With its vegetative reproduction and the excretion of toxic substances, it displaces other species.
• Narrow-leaved waterweed
  It was introduced as an aquarium plant and for the biological purification of water bodies. It spreads further through the drifting of shoot fragments and through water birds. Native plants are displaced by mass development in stagnant to slow-flowing waters.
• Muskrat
  In 1905, muskrats were deliberately released near Prague to use their fur for fur production. They spread further through migration. Muskrats exert strong grazing pressure on aquatic and riparian plants and, at times, on animals. Muskrats' burrows cause damage to hydraulic structures (e.g., dams).
• Letter turtle
  The various species were introduced through the pet trade and by private owners. They compete with the European pond turtle for food and space and exert strong feeding pressure on amphibian larvae.
• Crayfish
  The first animals were introduced to Europe (Poland) in 1890 and released into the wild. They have spread further through repeated restocking measures and independent migration. They can transmit crayfish plague, which has a very negative impact on native crayfish species (noble crayfish and stone crayfish).

The most important thing is to prevent the spread of further alien species. Once a species has become established, it is almost impossible to displace it again. A good example of this is the raccoon, whose populations we now have to live with. Prevention is the only way to stop such a spread.

Invasive species and those that could become invasive must be constantly monitored. An early warning system is currently being set up to identify new arrivals at an early stage. The involvement of the public is also helpful in this regard. The more observations are made, the better it is possible to assess whether and to what extent an invasive species is spreading and whether countermeasures are necessary. Anyone can therefore become part of the early warning and reporting system. The link to the reporting portal for invasive alien species can be found in the list of links below.

Since non-native species are always introduced by humans, everyone can help prevent this. Native species should be used in gardening and landscaping. Since 2020, this has also been regulated by the Federal Nature Conservation Act. Invasive plant species should not be sown or planted in your own garden either. As a rule, garden waste must not be disposed of in nature. Use the disposal options provided by the organic waste bin or the recycling centers. Invasive plants and animals do not belong in garden ponds either. Above all, no animals or plants should be released into the wild.