The new List of Invasive Species also featuring ‘killer shrimp’ that has arrived in Lithuania with ships2016-12-02
The new List of Invasive Species in Lithuania approved this week also includes Dikerogammus villosus. This very aggressive crustacean species was first discovered in 2015 in the Curonian Lagoon and the mouth of the Šventoji River. Called the ‘killer shrimp’, D. villosus are believed to have come to Lithuania with ships, attaching themselves to their different parts.
If this species continues to spread rapidly in the Baltic Sea basin, it will pose a great threat to the local species and habitats. Although killer shrimps are small, measuring from 3 mm to 3 cm, they are aggressive predators. They eat all smaller animals (other Amphipoda, juvenile fish, larvae of dragonflies, etc.), and the destruction of juveniles significantly reduces fish or even leads them to extinction in a water body. In addition, this results in decreased food for birds, frogs and other aquatic animals. This species is particularly resistant to oxygen shortage, temperature fluctuations and salinity, and consequently can spread in most varied water bodies.
According to Laura Janulaitienė, senior desk officer of the Nature Protection Division of the Ministry of Environment, the main measure in combating killer shrimps is the proper maintenance of ships and fishing equipment (washing and drying) to prevent the transfer of these invasive crustaceans into new water bodies. Using D. villosus as live bait in fishing is forbidden.
The new List of Invasive Species in Lithuania features other changes as well. For example, the subspecies of the red-eared slider has been replaced by the whole species of the pond slider. Therefore it is forbidden to keep, sell, breed or release to the wild animals of all subspecies of this species, including red-eared, yellow-bellied and Cumberland sliders.
Four species, in particular the zebra mussel, the acorn barnacle, the Chinese mitten and the fishhook waterflea, have been removed from the List of Invasive Species in Lithuania. In addition, the provision saying that individuals of certain invasive species may be exempt from destruction in green areas and plantations of urbanised territories has been eliminated. This provision has proved to be wrong as seeds of invasive species spread with the wind and through water and are transferred by animals and people. To prevent the spread of such plant species into other territories, these species must be destroyed in both cities and villages. These species also include the ash-leaved maple, the black locust, the rugosa rose, the low juneberry and the baby’s breath.
In the opinion of scientists, the invasive flora and fauna species cause great damage not only to biodiversity but also to the economy. For example, European Union loses about EUR 12.5 mln. annually due to these species. Therefore the EU biodiversity strategy to 2020 provides for identifying and prioritising invasive alien species and their pathways, and controlling or eradicating the most aggressive species.