Humpback salmon are native to rivers around the Pacific Ocean and are on the alien species list in Norway. The situation is confusing, and the questions are many. We have some answers, but by no means all.

What is humpback salmon?

Pink salmon is a Pacific salmon. In English it is called Pink salmon. Like our Atlantic salmon, it is a freshwater fish. They spawn in freshwater and the fry hatch in freshwater. The fry spend only a few days or weeks in the river before migrating to the sea to feed. After two years in the sea, humpback salmon migrate up rivers to spawn in August. They are then usually between 1.5 and 2.5 kg. In Norway, odd-numbered stocks are most common. They were abundant in 2017, 2019 and 2021.

Why are they here?

In the 1950s, Russia collected humpback salmon from rivers flowing into the North Pacific Ocean. Within a few years, several million fry were released into rivers on the Kola Peninsula, near Finnmark. Since then, humpback salmon have been caught in varying numbers, usually just a few, in Norwegian rivers. The largest catches are from rivers in the northeast of the country. Since it was the Russians who brought it here, many call it Russian salmon.

Are there many of them?

In 2021, more than 70,000 pink salmon were caught in Norwegian waterways. Most were caught in the north and east of Finnmark, but catches were reported from as many as 122 watercourses along the entire coast.

The salmon run in Tana was monitored with a video camera in the summer of 2021, and around 40,000 pink salmon were registered. Only around 2,000 have been fished out. If the spawning is successful, the run in two years' time (2023) could be very large. The females have around 2,000 large eggs per kg of fish.

Many humpback salmon have been caught in the sea, both with nets and on lures. Large catches have been reported from the Varangerfjord and west in Lofoten.

Do they spawn here?

Yes, pink salmon spawn in Norwegian rivers. Humpback salmon juveniles have been observed in several rivers in eastern Finnmark for several years, but in 2017 also in Jølstra in Vestland county. It is uncertain whether the pink salmon we are now observing are offspring from spawning in Norwegian rivers, or immigrants from Russian rivers.

Humpback salmon spawning in the river Luftjok.

Humpback salmon spawning in Luftjok in 2023 Film: Joachim Henriksen

Does pink salmon affect our Atlantic salmon, sea trout and char?

Humpback salmon spawn earlier in the fall than our salmonids, so they are unlikely to dig up their eggs. Our Atlantic salmon usually live for 2-5 years in the river before swimming to the sea to feed. Humpback salmon fry migrate out of the river after only a few days or weeks. If they are numerous, they can still "vacuum" the river for prey for a short period. This has a negative impact on Atlantic salmon fry and juveniles.

Humpback salmon die after spawning, and if there are many of them, they can pollute watercourses. How this affects our salmonids is uncertain.

Humpback salmon can carry parasites and diseases that infect our salmonids. Humpback salmon are not host to salmon lice.

How to distinguish humpback salmon from our salmonids?

Humpback salmon is a salmonid fish and has an adipose fin. They have similarities with our salmonids. In the sea and just after rising in the rivers, the humpback salmon is silvery and may resemble a silvery char. It has black spots on its tail fin and a black tongue, which none of our salmonids have. The picture above shows a spawning male salmon. The female salmon does not have a hump.

Humpback salmon fry are silvery and lack the mating marks that our salmon, trout and char have.

Humpback salmon is good!

Humpback salmon caught in the sea or recently reared in freshwater is a great fish to eat. The Minister of Fisheries had a taste and thought it was delicious! In freshwater, they quickly become unsuitable as food.

Can we get rid of humpback salmon?

Humpback salmon are here to stay. We don't know how numerous it will become, but the strong growth in 2017 to 2021 is alarming. Catches increased eightfold during those four years. There is a real concern that in odd-numbered years, humpback salmon may come to dominate in salmon rivers in the north of the country.

The government has set aside NOK 13 million for traps to catch pink salmon on their way up selected rivers in 2023. Traps are probably the most effective method, but gillnets, spearguns and pole and line fishing are all used to remove pink salmon from watercourses.

Tip. Here you can see an animation of the catch development in Norwegian rivers, 1976-2019. https://www.nina.no/Portals/NINA/Bilder%20og%20dokumenter/Fangst%20av%20pukkellaks%20i%20Norge.gif

Humpback salmon invading Norwegian rivers