Humpback salmon spawn every other year. In 2025, Norwegian rivers will again be invaded by humpback salmon. It is considered an alien species that may threaten Atlantic salmon. It is therefore undesirable in Norway. The Tanaelva is considered one of the world’s most important salmon rivers, but the challenges lie ahead when the river is to be protected against humpback salmon. They still don’t have a working trap to take out the unwanted humpback salmon before they go up the river to spawn. Humpback salmon Photo: Nils John Porsanger / news Humpback salmon naturally belong in northern parts of the Pacific Ocean. In the 1960s, humpback salmon began to spread to northern Norwegian rivers after being released on the Kola Peninsula in Russia. Today, humpback salmon are caught throughout Norway, but in Troms and Finnmark, humpback salmon are most numerous. Catches of humpback salmon in Norway have increased sharply in recent years, and the species also seems to be expanding its core area to the south of the country. It has been recorded that humpback salmon spawn in several Norwegian rivers. Source: Norwegian Institute for Natural Research – Risking destruction! This year, work has been done to find a more suitable place to have the trap, and several people news has spoken to are concerned that they will not get a perfectly good trap in Tanaelva. One of them is the local salmon fisherman Per Torleiv Ravna. – I have no faith in that, says Ravna to news. FISHING FOR A LONG TIME: Per Torleiv Ravna (59) from Tana says he has fished for salmon for 57 years. Photo: Håkon Mudenia / news Ravna believes the trap is too bad and puts the salmon at too great a risk. – You should try to stop it, but not with as great a risk as you are doing now, where you risk destroying the salmon population. Last year, the trap in the Tana River took out around six percent of all hump litter in the river. 120,000 humpback salmon swam by, while 7,666 were taken by the trap. It was then Norway’s largest trap for humpback salmon. Since then, the Veterinary Institute has been working to find a better place to close the river. This is how the trap works: The humpback salmon is taken out of the trap and slaughtered on land, while the Atlantic salmon escapes quite quickly. At least in theory. The video shows how a trap for humpback salmon works. The pictures are not from the Tanaelva. – Needs time – Last year’s salmon trap worked too poorly. That’s what project manager for the trap at the Veterinary Institute, Roar Sandodden, tells news. But he emphasizes that they bring good experience with them and the aim for next year is to set up a good trap for humpback salmon. Nils John Porsanger Can reduce the population – Humpback salmon is an alien species and the species database sees it as a species with a very high risk. This is what salmon researcher at NINA and expert on humpback salmon, Eva Bonsak Thorstad, tells news. – Large quantities of humpback salmon can, in the worst case, lead to reduced populations of our salmon in the rivers. When the humpback salmon has spawned, it rots and dies. Several people are concerned that dead, rotten fish in the rivers could have negative consequences. Lots of humpback salmon Last year almost as many humpback salmon were taken in Norway as there are Atlantic salmon in the country, says the humpback salmon expert. Every year around 400,000 of our salmon arrive Norwegian rivers and in 2023 alone, 360,000 humpback salmon were taken in Norway, explains Thorstad. – It is not at all desirable to have such large quantities of humpback salmon because it is an additional threat, says Eva Bonsak Thorstad. – If thousands of humpback salmon end up in individual rivers, as we have seen can happen, then there is a risk of negative effects on our salmon, says Eva Bonsak Thorstad. Arnstein Staverløkk / NINA Particularly big problem in the north In Troms and Finnmark in particular, humpback salmon have become a big problem. In 50 rivers in northern Norway, at least eleven times as many humpback salmon as Atlantic salmon were measured last year, explains Thorstad. Sandodden says this year they have tested a new place to have the trap, but it has proven to be demanding conditions. – We have actually identified a new area that we want to look into a little more closely and that we have already carried out thorough research on, says Sandodden. Roar Sandodden is a researcher and project manager for the humpback salmon trap in Tanaelva for the Veterinary Institute. Photo: Hanne Wilhelms / news It is indeed challenging to find a good solution for the trap. The size of the Tanaelva, as well as large variations in water level, mean that the trap must be well adapted. That’s why the trap must be big and it’s something new they’ve tried out with bad time, says Sandodden. – We are going to block the entire river, so we have to find an area where we can actually block it all. It is something new and it is something we need time to learn. – As if the devil is in the church! Fishing for Atlantic salmon has been a large part of the life of the local population for several hundred years, and is the very reason why people settled in Tana. – The governing authorities must understand that they are dealing with the most sacred thing we have in Tana. The river is sacred, says Per Torleiv Ravna. Ravna believes that other solutions should be looked at, such as local fishermen being able to remove humpback salmon. – It is an insult to us who live here that we are not allowed to fish in it. Local fishermen could catch 100,000 humpback salmon. NET: Per Torleiv Ravna fishes with nets in the Tanaelva, which was one of the few rivers in Norway where you could fish with nets before fishing was closed in 2020. Photo: Privat Now Ravna believes that the Veterinary Institute has not done a good enough job. – They are still learning what we have learned here over the course of 4,000 years. They will now learn that in two seasons. – It’s as if the devil is in the church, he adds. I think there will be more Local fishermen think one of the solutions could be to fish with nets, but Roar Sandodden disagrees. That would be too much catching of other species, he says. – Net fishing will not solve the problems with humpback salmon, because you will also catch a lot of salmon, says Sandodden. – We hope we will be able to develop a barrier that is as good as it is, and that does not harm the salmon. That is why we are doing this, he adds. But it may seem that next year will be a more difficult task: In 2023, just over 7,500 humpback salmon were caught in the Tanaelva, while around 120,000 swam past the trap. Now Sandodden says they have reason to believe there will be even more humpback salmon coming to Tanaelva next year. He still says that they hope to catch more humpback salmon than last year, but he does not want to guarantee that they will be able to do so. In comparison, over 230,000 humpback salmon were removed from rivers in northern Norway in 2023. Published 01/08/2024, at 23.10
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