Saving Norway's Endangered Atlantic Salmon
Not only is Norway home to 1,190 fjords, it also boasts the world's second longest coastline as well as countless rivers and lakes. World-renowned for its salmon, the Scandinavian nation is enriched by a large number of cold-water fish species that stay local and breed all year round and its extensive river system represents the world's largest breeding base for wild Atlantic salmon.
Atlantic salmon are intrinsic to Norwegian culture and a popular species for recreational anglers. Starting in early June and continuing into September, the "salmon flood" is a short but exciting time when Atlantic salmon migrate between freshwater and seawater – a year after hatching, they migrate to the ocean, spending between one and three winters there before returning to freshwater to spawn.
However, the population of Norwegian wild Atlantic salmon has been slowly declining over the past few decades and is now down by a quarter. As a result, Norway imposed strict daily and quarterly hunting limits, encouraging more anglers to adopt a "catch and release" approach.
Salmon fishing in Norway
Threatened by its Pacific cousin
The major threat to the Norwegian wild Atlantic salmon comes in the shape of its distant cousin, the pink salmon (also known as humpback salmon). Introduced into the Russian White Sea in the 1950s, they followed ocean currents to the Finnmark coast in northeastern Norway, and continued down to the south coast of Norway, quickly becoming an invasive species that caused catastrophic damage by disrupting food chains, introducing diseases, and upsetting the natural balance of native ecosystems.
The humpback salmon has proliferated to the extent that it could overwhelm the Atlantic salmon and other wild fish. It competes with native species in two ways: food and space for spawning grounds. And it competes well – humpback salmon enjoy the same food as its Atlantic cousins, they are aggressive, and they have high reproductive rates. Due to its 24-month reproductive cycle, the humpback salmon peaks in odd years. In 2019, the number caught by sports anglers surged to 13,900, which jumped to a record-breaking 111,700 in 2021 – 57% of all salmon caught in Norway. While almost all were in Troms and Finnmark, the invasive species has been caught in every county.
Dead and decaying humpback salmon not only reduce the oxygen content in rivers, but also reduce the number of other organisms that the river can support. The president of the Berlevåg Hunting and Fishing Association (BJFF) said, "We are concerned about the disease brought by humpback salmon. Moreover, when they die, the nitrogen content in the river increases, which means the death of wild salmon."
The humpback salmon's high spawning rates could wipe out the Atlantic salmon in the worst-case scenario
Photo: Knut-Sverre Horn, NRK
Escaped farmed salmon also add to the threat, competing with their wild cousins and adding pressure to already dwindling wild stocks. And as they are less genetically diverse than wild fish, they weaken the genome of the species after interbreeding.
Fishing for a Smart Solution
Traditional methods for protecting Atlantic salmon stock are labor-intensive, relying on volunteers to dive to the bottom of the river and identify humpback salmon with the naked eye – mainly by the spots on their tails – or by hand. This makes it hard to monitor and quantify the threat: Only fish that can be seen can be counted, many are missed, and their sex is impossible to determine.
Humpback salmon (male, above; female, below)
Wild Atlantic salmon
To address this challenge, Huawei partnered with Berlevag JFF (BJFF) to look for a technological solution that could automatically identify different fish species and then filter out the invasive species.
In 2021, the project saw the completion of two phases: First, AI algorithms were developed to identify fish species. Then in July 2021, Huawei and BJFF deployed a monitoring station with an underwater camera in Storelva River, which provides a continuous video stream and has generated tens of thousands of images. The hardware coupled with the algorithm can accurately identify Atlantic salmon with an accuracy of more than 90%.
The data collected can reveal accurate patterns of migratory behavior, monitor different types of fish populations, provide information for further research, and help prevent overfishing.
In June 2022, the partners deployed the filtering system in the estuary of the lower reaches of the Storelva River in Berlevag to prevent humpback salmon from entering the upstream channel, representing the world's first filtering system for salmon in natural rivers. The system features a mechanical on/off device to classify fish swimming through the ramp that allows local Atlantic salmon and Arctic red-spotted salmon to proceed upstream through the gate to complete the migratory spawning process. The invading species are blocked and diverted to a holding tank for subsequent removal. The solution cuts manual labor by 90%.
Installing the 12-meter filtering system / Photo credit: Bendik Skogli, Huawei
Testing the filtering system / Photo credit: Nils Johan Porsanger, NRK
Under the guidance of environmental protection agencies, the collaboration between a technology company and conservation organization has paid off. The solution is environmentally friendly, customized to meet local needs, and deployed with the support of the local community. The success of the pilot has not just given confidence to fishermen in Berlevag, it also gives hope that the solution can be applied in other similar rivers in Norway and Europe facing the threat of invasive species.
The probable next step for Huawei and its partners? To deploy the solution in Norway's salmon farms to reduce the environmental harm caused by escaped farmed fish.
Vegard Kjenner, Technical Director at Huawei Norway, said, "Installing a diversion system in a turbulent river is an extremely challenging task. I was impressed with the efforts of our partners, BJFF, and the local community. Here, people aspire to prove the role that good management has in saving rivers from environmental disasters."