Press release of the Administration of the Veľká Fatra National Park based in Martin and the State Nature Conservancy of the Slovak Republic “During the weekend, conservationists cleaned a site in the Veľká Fatra with the occurrence of the non-native red crayfish. This is the first recorded occurrence of this invasive species in Slovakia“, Martin, September 25, 2023
In the area of competence of the Administration of the Veľká Fatra National Park based in Martin (Administration of the Veľká Fatra National Park), a non-native invasive species of red crayfish (Procambarus clarkii) was found in a watercourse in the area with the 1st degree of protection. This is the first confirmed occurrence of this species in Slovakia. During the weekend, the Administration of the Veľká Fatra National Park, in cooperation with the State Nature Conservancy of the Slovak Republic (ŠOP SR) and the Slovak Fishing Association – Council of Žilina (SRZ), carried out the eradication of this invasive animal.
The occurrence of the red crayfish was confirmed in the Turčianske Teplice district on a section of approximately 1.5 km of a small stream subsidized by warm water from a thermal borehole, while the population here consists of several thousand individuals. There are also other non-native species of animals and plants on the site. The red crayfish is native to America and reaches a size of up to 15 cm. It is a carrier of crayfish plague, a disease to which our crayfish species are not immune and causes their mass death.
During Friday and the weekend, the Administration of the Veľká Fatra National Park, in cooperation with the SOP SR, organized a rapid eradication of this invasive animal associated with the modification of the site aimed at minimizing the possibility of its spread to new locations. Over the course of two days, more than 50 employees from these organizations, representatives of the SRZ – Council of Žilina and members of the nature guard cleaned the site and collected invasive crayfish and non-native freshwater shrimps. All captured individuals were subjected to professional monitoring and measurement by representatives of the University of South Bohemia in České Budějovice and subsequently disposed of.
As the zoologist of the Veľká Fatra National Park Administration, Mária Apfelová, explains: “After draining the site and collecting the crayfish, lime disinfection of the bottom and banks of the stream was applied to prevent the transmission of crayfish plague and to eliminate young crayfish that could not be caught. The site was collected repeatedly even after the application of lime until late in the evening. So far, about 4000 crayfish have been caught and more than 5000 more during this action. During the weekend, more females with cubs were caught in the number of more than 3400 pieces. To date, more than 12,400 individuals of this non-native invasive species have been destroyed at the site.” The term eradication is adapted to the second breeding season of crayfish for its greater efficiency. The measures will continue until mid-October. Subsequently, 2-year monitoring of the site and capture of the remaining individuals will be provided.
The spread of alien invasive species is prohibited and violations of this ban are subject to sanctions. All alien invasive species pose a serious threat to our native species and ecosystems. The issue of alien and invasive species is regulated by Act No. 150/2019 Coll. on the prevention and management of the introduction and spread of invasive alien species and its implementing decree of the Ministry of the Environment of the Slovak Republic No. 450/2019. The origin of these species in the area in question is being investigated by the Slovak Environmental Inspectorate.
More about the issue of invasive species can be found on the website of the State Nature Conservancy of the Slovak Republic – https://invaznedruhy.sopsr.sk/. The site also includes a rapid alert system through which the presence of alien invasive species can be reported.
Additional information:
The red crayfish (Procambarus clarkii) is native to America, from the region of northern Mexico. The crayfish reaches a size of up to 15 cm, adults are distinctly red, young ones are variable in color from brown, through rusty to red. It also digs 2 m long underground burrows and can live out of water for a long time. It is therefore adapted to short-term drying of sites and is able to walk up to 3 km per night on land.
The red crayfish has a great reproductive ability – the female can raise 600 young 2 times a year under suitable conditions. This species was planted in Europe for the first time in 1973 in Spain, where it gradually spread throughout the country with the help of man and by his own efforts. It was also transferred to Italy, Portugal and France, where it also successfully caught on.
In the wild, it is also known from Great Britain, Germany, Switzerland, Belgium and the Netherlands. In recent years, its occurrence has also been recorded in Hungary and Poland. It has also been found on several islands around Europe. It is also known from China, some countries in Africa or the Far East. It has not yet been detected in the Czech Republic, although its discovery is probably only a matter of time.
Experience from abroad shows that its eradication is extremely difficult and is rarely successful after the first intervention. More information can be found on the website of the State Nature Conservancy of the Slovak Republic: https://invaznedruhy.sopsr.sk/rak-cerveny-procambarus-clarkii/
The press release was prepared by the Department of Nature Conservation of the Veľká Fatra National Park Administration based in Martin in cooperation with the Department of Communication and Promotion of the State Nature Conservancy of the Slovak Republic
