Rapid Eradication and Confination of Marbled Crayfish Populations in Moravia, Czech Republic 

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Project ID number: 6709
Location: Moravia, Czech Republic
Programme: IUCN Save Our Species (SOS)
Funding source: EU IAS Rapid-Response Fund
Total budget: €38 520.51
Project duration: 26th March 2026 – 31st March 2027  
Lead project partner: Nature Conservation Agency of the Czech Republic (NCA CR)

Project objectives and scope

The objective of the project is to rapidly halt the spread of and eradicate or contain two newly discovered populations of marbled crayfish (Procambarus virginalis) in Moravia, specifically in the localities of Mohelnice (Olomouc District) and Šoulet (Zlín District).
This non-native invasive species poses a serious threat to our native crayfish species and entire freshwater ecosystems. Due to its ability to reproduce without a mate (parthenogenesis), rapid expansion, and transmission of crayfish plague, it can spread very quickly and cause significant ecological damage.
Both populations were discovered in the spring of 2025 and, since they are currently found only in isolated water bodies, their complete eradication remains a realistic possibility with timely intervention.

The project includes two main measures:

•    complete eradication of one population by filling in the affected water body; 
•    control of the second population through the introduction of predatory fish and the intensive use of crayfish 
      traps. 

The project contributes to the protection of biodiversity, strengthens the ability to respond quickly to the occurrence of invasive species, and raises public awareness of this issue.
The project’s implementation is fully in accordance with applicable Czech legislation as well as Regulation (EU) No. 1143/2014 of the European Parliament and of the Council on the prevention and management of the introduction and spread of invasive alien species. The project also supports the objectives of the EU Biodiversity Strategy by helping to prevent the establishment and negative impacts of a newly spreading invasive species.

Project activities

The project activities will also include monitoring of surrounding areas through visual observation, the use of traps and eDNA analysis; the installation and operation of crayfish traps; and testing for crayfish plague. The project also includes informational and awareness-raising activities such as the installation of information panels and the organisation of a specialised workshop.

Planned results and outcomes

1. Eradication at the Mohelnice site
During the winter, and in agreement with the landowners, a small body of water in which marbled crayfish have been confirmed will be filled in. Temporary protective barriers will be installed to prevent the crayfish from escaping, and the site will subsequently be monitored.

2. Eradication at the Šoulet site
The larger pond at the Šoulet site will be managed through a combination of biological control and trapping. European eels (Anguilla anguilla) will be introduced to help regulate the population of juvenile crayfish, and a sufficient number of traps will be deployed for monitoring and targeted trapping.

3. Site monitoring
Monitoring will take place from spring to autumn and will focus on assessing crayfish abundance, detecting potential spread to surrounding waterbodies, and evaluating the effectiveness of the interventions through trapping, visual surveys, and eDNA analysis.

4. eDNA analyses and testing for crayfish plague
Water samples will be collected regularly at both sites for environmental DNA (eDNA) analysis. Captured individuals will also be tested for the presence of crayfish plague.

5. Public awareness and prevention of spread
The project also includes educational and awareness-raising activities aimed at preventing the spread of invasive species. This will include a public workshop, the production of leaflets, and the installation of information panels warning of the risks of releasing non-native species into the wild.

Project benefits

The project will help reduce the occurrence of marbled crayfish, protect native crayfish species, and lower the risk of crayfish plague transmission. It will also promote the use of modern monitoring methods, raise public awareness, and establish a model procedure for rapid response to the appearance of invasive species in the Czech Republic.