Live tracking of fish with Link LoRa at Hellstranda, Norway

Written by: Hilde Johannesen

Scientists at the NTNU science museum have, in collaboration with Nye Veier (New roads) and Rambøll, installed a Link LoRa network at Hellstranda in Stjørdal, Norway, to investigate the new road buildouts’ effect on the resident fish populations. Adult sea trout have been tagged and recorded in real-time with the help of several deployed Lives in the estuary. In previous projects, the buildout effects have only been investigated before and after. The goal of the live tracking in Hellstranda was to first look at the typical situation before the developments and then use the data to regulate along the way if the fish experiences high levels of stress. Real-time investigations of the status of the fish using Link LoRa and Live may discover negative impacts earlier on for a more effective mitigation strategy. 

Nye Veier (New roads), NTNU – University Museum, Rambøll, and Thelma Biotel are collaborating on the project, where Thelma Biotel developed the Link LoRa real-time tracking system.  

The Link LoRa Live tracking telemetry system 

The Link LoRa real-time monitoring program was established in January 2021. The purpose of this system is to monitor the stress levels of adult sea trout. The Link LoRa system consists of deployed Lives (transceivers), which send the data to an antennae node connected to a local LoRaWAN network located on the rooftop of Hell Hotel. When the antennae node obtains the data from the transceivers, it is forwarded to a server via mobile 4G internet.  

The antennae node and Main unit of the Link LoRa system – Photo credit: Jan Grimsrud Davidsen

Collecting data on depth, temperature, and speed 

The sea trout were tagged with acoustic transmitters, and four Live listening stations were deployed to record the fish as they swim past. As there has been no filling of the beach zones from the deployment of the system until now, the data collected can be used as a reference for what is the “normal state” of the fish populations. The transmitters implanted into the sea trout measure the depth, temperature, and speed of the fish, and this can be a good indicator of their health.  

An important step in the lifecycle 

The area of the E6 road buildout at Hellstranda is an estuary environment and an important zone for sea trout to migrate to for feeding. Further, a part of the sea trout population resides here all year around. If the fish experience stress as they are in the feeding stages, their growth and survival could possibly be influenced. Short-term stress should not have a big impact, but it is the long-term stress that the investigations aim to uncover and mitigate, if present.   

Nye Veier published an article in 2021 which can be accessed here. 

For more about our Link LoRa, live-tracking system, click here.