The pink salmon or humpback salmon is an invasive species in Norwegian rivers. The fish has a two years cycle, which means that the fish that spawn comes back from the ocean after two years. Since the fish migrates back to the rivers after two years, and then die there are two separate populations, one highly successful that enters the rivers in odd-numbered years and one much less successful that enters in even-numbered years. This behaviour is the same for the natural habitat of the pacific and here in Norway where the fish is unwanted.
The County Governor of Troms and Finnmark submitted a tender to investigate the fish population of 4 Finnmark rivers, Karpelva, Vesterelva, Vestre Jakobselv and Neiden, which were awarded to Mohn Technology AS this spring. The main goal is to know more about the pink salmon population in even-numbered years like this year of 2024, and also compare natural species behaviour compared to last year which was a pink salmon year.
We have to this date registered a few dozen pink salmon, which is quite small compared to the tens of thousands that were captured in these rivers in 2023. See example video of a prime example below, taken at Karpelva.