PROJECT DESCRIPTION
BACKGROUND
Coypu (Myocastor coypus) and muskrat (Ondatra zibethicus) are large semiaquatic rodents of American origin that are now found in a wide range of habitats in wetlands, lowlands and reed areas in Europe. Coypu and muskrat populations can be very damaging to their environment. They feed on roots of bulrush and reeds and can consume up to 1.5 m2 of vegetation per night per animal. Endangered species, such as freshwater pearl mussel (Margaritifera margaritifera), little bittern (Ixobrychus minutus) and Eurasian bittern (Botaurus stellaris), suffer from habitat damage and egg destruction. By destroying reed habitats, these invasive alien species (IAS) also drastically affect ecosystem services, diminishing the filtering effects of this habitat and its buffering capacity. By digging into dikes and quays, they seriously increase the risk of floods and human health risks. Moreover, the species damage commercial crops, leading to significant losses in yield. Finally, muskrat and coypu can be carriers of various diseases dangerous to human and pet health such as zoonosis. Coypu and muskrat management operations are a core activity of the Dutch Water Authorities, where trapping operations help minimise the muskrat population and prevent coypu from spreading in the Netherlands.
OBJECTIVES
The LIFE MICA project aimed to improve the efficiency of trapping of invasive coypu and muskrat, which endanger protected species, habitats and ecosystem services, by demonstrating new innovations in detecting and management methods in the Netherlands and neighbouring countries. Specific objectives were to:
- prevent the spread of these IAS through better international cooperation;
- detect low populations of coypu and muskrat using e-DNA techniques (environmental samples without obvious biological source material), apply rapid management actions, and encourage preventive actions;
- manage the existing populations of these IAS;
- protect the lowlands from flood risk, enhance ecosystem resilience for (rain) water capture;
- protect vulnerable species against the impacts of coypu and muskrat and restore affected ecosystems;
- protect crops from these IAS.
The project directly implemented the EU Regulation (1143/2014) on the control of invasive alien species (IAS) and also the EU Biodiversity Strategy to 2020, and the Birds and Habitats directives where actions lead to improvements in the conservation status of annex-listed species.
RESULTS
Major outcomes in the implementation included:
- the successful improvement in international cooperation and project implementation across participating countries;
- an enhanced detection capabilities through the development of e-DNA methodology, aligned with trapper observations;
- identification of migration routes of muskrats by DNA-Mapping;
- efficient and cost-effective management of Invasive Alien Species (IAS) using e-DNA, particularly in low-density areas;
- the development of a smart camera tracking system, integrated with image-recognition software (Agouti), demonstrated high precision in identifying rodent species;
- encouraging results from smart traps, despite not fully meeting planned objectives, with continued cooperation for further development.
Overall, international cooperation between Belgium, Germany and the Netherlands has improved and all three countries involved in the project worked smoothly together to implement the project. The project also involved Denmark which showed interest in the methods developed. Detection of low populations of coypu and muskrat has improved with the development of suitable eDNA methodology, of which results matched the observation of the trappers. All along the project, the partners have managed existing population though traditional and smart trapping.
Environmental DNA (eDNA) analysis provided the most conclusive results, offering an efficient way to manage IAS by reducing costs and enhancing the tracking process. The project showed that this method is most suited/cost efficient to follow-up after an intensive trapping effort and in low density areas, as well as to confirm that all individuals have been removed from the waterways and prevent re-population. They also showed that semi-randomised sampling is sufficient to obtain reliable results compared to full coverage sampling. This method has good replicability and transferability potential as methods and tools can be easily applied for monitoring other invasive species but also protected species.
Upon detection of invasive species in a region, identifying migration routes is crucial for effective management. This allows for targeted actions to prevent a continuous influx of these species. The LIFE MICA project developed a method which allows identification of relationships between different muskrat populations by genetic analyses (DNA-Mapping) and helps to identify their migration routes.
Through the development of smart cameras tracking system, the project managed to assemble an impressive database of pictures that has been added to Agouti, an image-recognition software that filters non-rodent from rodent species. Agouti has been upgraded throughout the project lifetime, resulting in a reliable software that now identifies species with high precision. The majority of collected images are annotated automatically resulting in a reduced workload.
Results obtained for smart traps are encouraging even if planned objectives have not been completely reached. Only 25 traps out of 50 planned were tested for a limited time (first tests in 2021, final implementation since 2022) as many developments and improvements were needed, resulting in excessive costs. This resulted in a validation period that was too short. However, these devices show significant potential, and multiple organisations plan to continue the smart life traps development in collaboration, including ROBOR (the producer of the smart life traps), LIFE MICA partners, trapping organisations, government officials and companies, and organisations specialising in smart systems and AI-recognition software.
Regarding the expected benefits for the ecosystems (prevent flood risks, protect vulnerable species, restore affected ecosystems, and protect crops), it is too early to assess given the challenges encountered by the project and the delays accumulated in several actions carried out. In fact, although the management of IAS has been showed to be beneficial in other cases and can probably lean towards the achievement of those objectives, the delays did not allow the project to properly evaluate the impact on ecosystems and other species. Population reductions of at least 50%—and in some areas up to 100%—were expected. However, while catch rates increased over the years, most areas show a stable population trend for both Muskrat and Coypu. Reef-bed extent, planned to improve, was relatively stable throughout the project, as was the occurence of monitored endangered species.
Challenges and future directions include:
- attention to delays in project actions that affected the assessment of ecosystem impacts;
- further efforts aimed at the realisation of planned population decreases, as stability was observed in Muskrat and Coypu populations;
- the effectiveness and positive impacts of the tested methods compared to pre-project technologies.
In conclusion, LIFE MICA, while facing challenges and statistical uncertainties, can be considered a partial success. The project achieved significant advancements in detection methods, international cooperation, and efficient management of invasive species. The tested methods work, which is a significant improvement compared to the technology available before the project began. The lessons learned and ongoing collaborative efforts ensure a continued focus on refining strategies for the benefit of ecosystems, vulnerable species and agricultural interests.
