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2nd Joint Workshop Life MICA and Life RIPARIAS

On the 13th of July 2022 in Brussels, the 2nd joint workshop Life MICA/Life RIPARIAS took place. About 30 participants from different countries and institutions dealing with invasive alien species (IAS) attended the hybrid event.

Photo 1: Invitation page

The workshop started with a plenary session in which the Life MICA and the Life RIPARIAS project were presented to the auditorium. Thereafter, two break out groups were created and participants could join either the group of the MICA project or that of the RIPARIAS project.

The aim of the Life MICA parallel session was to discuss transfer and replication opportunities for the innovative techniques for monitoring and management of IAS developed by Life MICA: smart camera traps, eDNA analysis, DNA mapping and smart life traps were presented.

There was high interest in how to use the Agouti platform for analysis of camera trap images with the Artificial Intelligence (AI) for other projects dealing with IAS. The high adaptability of the AI to be trained in recognizing other IAS was pointed out and the possible reduction in work effort for a broad scale monitoring with camera traps was discussed.

Furthermore, the e-DNA method was intensively discussed by the participants who asked about the suitability of the sampling protocol and analysis method for detection of other IAS or protected species in water samples.

Interest in the prototype of the smart life traps was manifested by participants, who were curious about the operating principle of the AI and the suitability in areas in which protected (non-target) species occur.

Photo 2: One of the Mentimeter questions with results

At the end of the break out session, participants were asked to answer some ‘Mentimeter’ questions about transfer and replication opportunities for each presented method and to share their opinion about which other invasive or non-invasive species could be monitored and managed using the techniques of the Life MICA project.

The day before, on the 12th of July, the follow-up ‘Conference on the management of vertebrate invasive alien species of Union concern – incorporating animal welfare’ coordinated by the International Union for Nature Conservation (IUCN) had taken place. Here you can find the very interesting documentation and reports.

> EASIN page
> EC IAS page

Open day Life Mica in nature reserve Gelderse Poort

On September 16, Life Mica organized an open day in Gendt. This is located in the Geldersepoort nature reserve, one of the project areas. Local residents and various (nature) organizations attended the open day.

The morning started with an introduction to the muskrat and coypu and the problems these animals cause. Then all of Life Mica’s innovative methods to detect and trap muskrats and coypu were discussed: environmental DNA (eDNA), DNA mapping, smart cameras and smart life traps.

Also other animal species?

The attendees were enthusiastic and asked many questions. There were also some interesting discussions, for example about whether these innovative methods can also be used to detect other animal species.

With their own eyes

After the presentations, it was time to see the innovations with their own eyes. The participants went into the nature reserve and saw how water samples for analyzing eDNA were taken with a sailing drone. They also learned about the difference between a traditional and a smart trap.

Efficiency

Muskrat trapper Kees Schep sees the advantages of the smart life trap . “Traditional traps have to be checked regularly and that is hard work,” he told the visitors. “Thanks to the smart traps, we will be able to work more efficiently in the future.”


Latest progress in Smart Life Traps: more catches and detailing

This project aims to develop smart life traps that use AI image-recognition. By incorporating AI we prevent unwanted bycatches of protected species as European beaver or otter and only catch target species like coypu and muskrat. More catches are made in the field and more details on the traps are improving.

By now, ten smart life traps are in use in Germany, five in Belgium and ten in the Netherlands. Two coypu and six muskrats were caught on either side of the Dutch-German border. In the past months AI image-recognition software was improved by using field images from the smart life traps. Also, the module works now both on- and offline, even when it is not connected to the internet.

Hardware

On hardware, the traps are improved as well. Mesh is mounted on both sides of the cage and the ground plate is elevated in order to obtain better pictures from animals that enter the trap. Also, mesh is mounted in front of the camera system for protection.

This summer the hardware will further develop with improvements like a stronger magnet and battery. Also, the AI image-recognition software will be enriched with images of otters and raccoons. The online message sent to the trapper will soon improve by always sending correct information on battery, GPS and trap status.

Active smart life trap at Sint-Maartensheide – De Luysen, April 1th 2022.

The message that is send to the trapper.

First results on survey methods and materials

A survey was made on methods and materials for eDNA, DNA sequencing/mapping, smart cameras and smart traps. Although responses were few, preliminary results include excellent scores for DNA methods and useful field results for smart systems.

A total of 21 responses was too few for statistical analysis. This was the first survey, so possible effects may be analysed over time.

However, the first results include excellence in protocols for handling both DNA methods. It looks like eDNA is an excellent warning system and DNA sequencing/mapping is extremely effective for determining migration routes.

Challenges

Challenges are the intensive maintenance of materials (eDNA and DNA sequencing/mapping), the slow process (DNA sequencing/mapping) and the contradictory in work: trappers understandably prefer to work in areas with dense populations of rats, whereas eDNA methods focus on areas with few muskrats (eDNA).

Smart systems

For the smart systems (cameras and traps) the first results show that they are both multifunctional and can be used for different species. Smart life traps tend to render better catches. Design of the smart cameras is considered excellent.

Improvement

Improvement on the traps is needed on the hardware (battery and magnet), software (AI image-recognition) and the message to trappers (battery level, GPS and trap status). On the smart cameras there is room for improvement on the AI image-recognition software used for detecting muskrat or coypu and on the speed of processing.

A new survey will be held in October.

DNA Mapping in Friesland is going well

In January 2022, the results of the first round of DNA mapping in Friesland were presented to the muskrat fighters. Based on the results, the catch intensity along the probable inflow locations in Friesland will be increased by placing a cordon of traps here. Smart wildlife cameras have been installed at the intake locations.

Red cross: influx from outside Friesland
Yellow cross: transfer in Friesland

Tail tips

In addition, in the period from February 2022 – February 2023, the tail tips of all muskrats caught in Friesland will be collected for follow-up research. The aim is to collect 100 muskrats this year, spread as much as possible across Friesland. More than 50 muskrats have already been collected.

eDNA subproject is scaling up

The current aim for the muskrat eDNA part of Life-MICA is scaling-up and real-life implementation of the eDNA approach and transference of sample processing to the water laboratories.

In order to compare results between the lab at the University of Amsterdam and the labs at Wetterskip Fryslân and Waterproef (Noord-Holland) we started sampling this year in regions with a higher chance of muskrat presence. For Fryslân this meant sampling near the borders, and for Noord-Holland sampling in a region where they have trapped the most muskrats in the past few years. Both regions have a low population of muskrat compared to other parts of the Netherlands.

Fryslân

In Fryslân a polder that has been designated as empty of muskrat was also sampled to determine if the eDNA results matched the evaluation based on traditional tracking methods (polder empty of muskrat), this did indeed match (Fig 1, region indicated by blue arrow). Figure one shows the results of sampling in Fryslân.

As of 29-06-22, 449 monitoring samples haven been taken in Fryslân, most by boat, as well as 78 localisation tracks, 70 point samples and 9 control samples (taken to confirm no more muskrat are present after catch actions).

As of 22-06-22, 34 muskrats had been trapped in the sampled areas (27 in waterways/tracks with eDNA and 7 in tracks without eDNA, but that were adjacent to tracks with eDNA).

Noord-Holland

In North Holland, there were many more traces of muskrat eDNA in the sampled region than in previously sampled areas. This allowed us to make a good comparison between the laboratories. But the high number of samples containing muskrat eDNA makes this region less suitable for the mainstream eDNA approach. Because of the significant population of muskrat in the area in the period of May/June the trappers focussed on catching the muskrats in this area. Figure 2 shows the catches of the muskrat overlayed on the eDNA results.

As of 22-06-22, 215 muskrat had been caught in the sampled area (182 in waterways/tracks with eDNA and 33 in tracks without eDNA, but again these were adjacent to tracks with eDNA). In Noord-Holland 167 monitoring tracks were sampled, as well as 163 localisation tracks and 181 point samples.

Most tracks in Noord-Holland were sampled by hand, which is more labour intensive and time consuming than sampling by boat. Areas with these population levels are more suited for follow up with eDNA after an intensive trapping effort, to determine if there are remaining muskrats, rather than the method used for monitoring areas that are historically empty or have very low presence.

Coypu

For the Coypu the aim is not so much scaling up but determining how to best integrate the eDNA method in the tracking efforts. Coypu behave differently from muskrat and are also caught alive in cages instead of traps in burrows. This makes certain parts of the field approach less useful for coypu (localisation of burrows). 31 areas were sampled for coypu presence, and as of 22-06-22, there were 23 catches, of which 21 corresponded with eDNA signal.

Wetterskip Fryslân and Waterproef processed all the samples of their respective regions for this year, and are thus capable of routinely processing samples. Transfer of analysis of coypu eDNA samples has been initiated with Aqualysis.

Figure 1. Results monitoring Fryslân. Green: eDNA negative, Yellow: eDNA weakly positive and Red: eDNA positive. Both yellow and red tracks are followed up in the protocol.
The blue arrow indicates the polder which was sampled in order to determine if there were muskrat remaining in an area that had been marked as empty by traditional methods. This polder was sampled by hand/quad.
Figure 2. Sampled area Noord-Holland
Green: eDNA negative, Yellow: eDNA weakly positive and Red: eDNA positive.
Blue triangles: catches

Mallard the most photographed with the camera trap

In the different project areas 47 camera traps have been placed to detect muskrat and coypu presence. These cameras take a sequence of images when they are triggered by movement.

Afterwards trappers need to annotate these sequences to see which species is on there. Over 80.000 sequences have been annotated so far. The most commonly seen species on the cameras are mallards.

Artificial Intelligence

Since June of 2021 we have been using the Artificial Intelligence (AI) developed by the Agouti team to help annotate our images and ease the workload. We started a project with the team from Agouti to retrain their AI to better work for water conditions. Hopefully this will further optimize the workflow for detecting muskrats and coypu with camera traps.

Figure 1: distribution of the species observed on the camera’s.
Figure 2: muskrat caught on camera


A further catch with the ‘intelligent live traps’

Intelligent live traps have been set up at the Aschauteiche ponds to further test and develop the AI module of the live traps under real field conditions. On 6 April 2022, the first coypu was caught in the German project areas. The progress in development here has shown that the AI correctly detects coypu and other species and non-target species are not caught.

On the night of 6 April, we had the first capture of a coypu in the project area Aschauteiche. The intelligent live trap, equipped with the AI module with the recognition software, detected a coypu as it entered the trap, activated the closing mechanism, and then sent a message about the catch, including pictures, to the trap supervisors.

Intelligent live trap at the ash ponds

A total of 10 intelligent live traps are currently set up in Lower Saxony, including at the Aschauteiche, an area where not only the invasive species coypu occurs, but also to raccoons and common raccoon dogs, as well as protected species such as the otter.

The image recognition software installed in the back of the traps was able to document rats, mice and raccoons in the trap. Here, the AI module is being further trained to improve the system.

Wildlife cameras that monitor the trap prototypes from the outside and document the presence of animals with the trap provide additional certainty. This allows us to evaluate the functionality of the prototype more precisely.

Below, you can find some pictures of the coypu capture, as well as photos of the raccoons’ nightly ‘forays’ into the traps.

The coypu observed from the photo traps that supervise the intelligent cages.
The KI systems collects photos inside the cage to evaluate which animal should be caught and which are the non-target species.
As soon the KI system has taken the decision to close the trap and catch the coypu, Telegram informs the trappers sending a message with the necessary information and pictures of the catch. Thereafter, the coypu is took out from the catch.
Here an example of a raccoon going out of the cage, which was correctly not caught.
The same raccoon as above, documented by the image recognition software of the trap.

‘Smart life trap’ recognizes and catches first coypu on Dutch border

For the first time a coypu has been recognized and caught by a ‘smart life trap’, rigged with image-recognition on the Dutch-German border near Winterswijk. This animal species is not native to Europe and this new technology will help water authorities to catch them.

A ‘smart life trap’ uses image-recognition to recognize and trap animal species: the cage closes catching muskrats and coypu, while it remains open when entered by, for example, birds or otters. In January a coypu in the Wooldseveen moor near Winterswijk walked into the cage, was recognized and caught. It was the first catch in the field, after a long preliminary phase of testing and refining.

More efficiënt

Pest controller Jari Bremer: “With image-recognition in the cage we avoid unwanted by-catches and we are more efficient, we only catch animals that pose a risk. It’s great that we’re able to catch only the right animals, thanks to a camera and technique that keeps improving.” Bremer received a signal from the cage in Winterswijk on his smartphone and confirmed the catch in the field. He delivered ‘smart life traps’ in German project areas as part of the Life Mica project. This will happen in Belgium as well.

Risk to dikes and nature

Muskrat and coypu are alien species in the Netherlands. They have no natural enemies, they weaken banks and dikes and they interfere with inland species. In the past half century the muskrat population declined from half a million to less than 10%. In 2021, fewer than 45,000 muskrats were caught in the Netherlands. Hundreds of coypu are caught in the Netherlands along the border, but they are hardly found further inland.

Up to the border

The water authorities want to push back the muskrat up to the border alike. “Technical innovations will help”, says Pascal van der Linden, team leader pest management. Such as image-recognition, which now yielded the first catch. “This was preceded by a period in which we created an extensive image bank with all kinds of species, modeling and data analysis. For example, the camera has also been tested in a German otter center.”

50 traps

A total of 50 traps will be rigged with image-recognition based on AI software, supplied by Robor Electronics bv in Bentelo. The ‘smart life trap’ will further develop in the coming years. Muskrattenbeheer Rivierenland works on the Dutch-German border between Haaksbergen and Groesbeek, with a working area that extends over 4 water boards between the border and the sea: Rijn and IJssel, Vallei and Veluwe, Hollandse Delta and Rivierenland.

Does DNA mapping help to manage the influx?

One of the components of the Life MICA project is a study into the interrelationship of muskrats. This allows migration routes to be determined. In the period February 2020 – February 2021, muskrat trappers in the Netherlands, Belgium and Germany collected tail tips from muskrats for this research.

Central to the research is the muskrat population in the province of Friesland. Samples were collected in Friesland and in a surrounding area. As a reference, samples were also collected in Germany (Vechte), Flanders, Rivierenland and Tiengemeten.

Research questions

Three research questions have been formulated for the study:

  1. Can source areas be recognized through a difference in DNA profile?
  2. Is there reproduction within Friesland?
  3. Is there immigration from surrounding regions?

Source areas and Friesland

The results of the DNA analysis are plotted in the graph above. Each color represents a trapping organization. Red dots between yellow dots means that the muskrats trapped in Friesland show a strong relationship with the population in Zuiderzeeland, and especially the Noordoostpolder. The 3 free red dots on the right side represent the ‘own’ Frisian population.

Origin of muskrats trapped in Friesland

3% of the muskrats sampled come from the presumably ‘own’ population of Friesland. The distribution of the origin of the other sampled muskrats is:

  • 58% Noorderzijlvest
  • 26% WDO Delta
  • 13% Zuiderzeeland

The answers to the questions:

  1. Can source areas be recognized through a difference in DNA profile?
    Yes, the DNA method used can be used to tell the different source areas apart.
  2. Is there reproduction within Friesland?
    Yes, some animals have been found from the (presumably) original muskrat population in Friesland.
  3. Is there immigration from surrounding regions?
    Yes, except from North Holland, muskrats have been found from all surrounding areas.

What’s next?

Based on the results, the trap intensity along the probable inflow locations in Friesland will be increased by placing a cordon of traps here. In addition, in the period from February 2022 – February 2023, the tail tips of all muskrats trapped in Friesland will be collected for follow-up research.