FISH MONITORING IN HYDROPOWER PROJECT
At the Finsjö Upper Power Plant in Emån, a new type of turbine was installed in the autumn of 2023. It is called an Archimedean screw turbine, with the idea that fish can safely pass through the screw both upstream and downstream. This screw turbine is the first of its kind to be installed in Sweden and will be thoroughly monitored by Karlstad University over a five-year period.
FOLLOW-UP WITH FISH COUNTERS
TiVA was commissioned to deliver no less than three fish counters and an underwater camera as crucial tools in the follow-up work. The fish counters are also equipped with integrated antennas capable of reading so-called PIT tags. This technology is similar to how regular contactless payment cards work; the antenna mounted on the fish counter generates a magnetic field, providing power to the small passive transmitter implanted in the fish as it swims through the antenna. When activated by the magnetic field, the transmitter sends out its unique ID number, which is captured by a reader connected to the PIT antenna.
This technology creates entirely unique opportunities when combined with a fish counter. A common approach is to capture, for instance, trout fry via electrofishing in their spawning areas and tag the fish with the transmitter. When the fish then pass by the antennas, the ID number is captured along with data such as the time, size of the fish, as well as images and video footage. Because the transmitter is passive and only activated by the antenna’s magnetic field, the fish can be tracked throughout its entire lifespan. This creates entirely unique conditions for collecting valuable data over time without the need to handle fish through, for example, trap capture.
COMPLETE PIT SYSTEM FOR OUR FISH COUNTERS
In conjunction with the project at Finsjö, we developed the integrated PIT system for our TiVA FC. The antenna itself is attached to one end of the fish counter and only adds approximately 8 cm to its length. The reader, power supply, and control unit are all housed in the fish counter’s equipment cabinet, integrating directly with the fish counting system. This ensures that all registrations from the PIT system are matched with the registrations from the fish counter. All data is then, of course, available together on our web platform. The PIT antenna with a reader is now offered as a valued addition our fish counters.
Video from Uniper showcasing the collaboration on the Finsjö project
PIT antenna mounted on fish counter
One of three fish counters installed in Finsjö