Photo: Arnt Mollan — *Gytelaks. Foto: Arnt Mollan*

Full speed ahead on the spawning ground

In October, before the ice settles, salmon spawn in many rivers. In winter-warm rivers in the south, they tend to spawn later. But no matter when the spawning starts, the salmon have dressed up. The spawning costume of the male salmon is particularly colorful and beautiful. The male draws color and energy from the flesh of the fish. The skin becomes reddish and the lower jaw gets a proper hook. The hook is well suited for fighting, and both the color and the hook are designed to impress the female salmon.

The female is not as colorful in her skin as the male. She becomes more brownish. Instead, female salmon invest in the production of large, red-orange eggs - as many as 1,450 eggs per kilogram of body weight. Spawning is the goal in the life of a wild salmon, as it allows them to pass on their genes to the next generation.

The roe is placed in a spawning pit, which the female salmon digs. She uses her tail to dig and her gill fin to measure the correct depth. The toughest male salmon is immediately in place and fertilizes the roe, which the female salmon quickly covers with a protective layer of gravel. The roe will then lie there under the gravel through a long winter and develop.

At the spawning grounds, there are always a few little lurkers that we call spawning parr orsneakers. These little guys are sexually mature male salmon that have not yet been on a feeding migration in the sea. They lurk and help fertilize the eggs.

Photo: Namsblank — *Namsblanken drar aldri til havet. Foto: Per Harald Olsen, NTNU*

In two places in Norway - in Upper Namsen in Trøndelag and in Otravassdraget in Agder - there are two very special salmon populations. What they have in common is that they do not migrate to the sea. Both female and male salmon reach sexual maturity in freshwater. They have lived in isolation since the land uplift separated them from the sea-migrating salmon almost 10,000 years ago. We call them relict salmon.

The Namsblanken in upper Namsen lives its entire life in fast-flowing river water. The Byglandsbleka salmon use the Byglandsfjord as a nursery area. The spawning season for the Namsblanken coincides with the spawning season for the sea-going salmon further down the watercourse. The Byglandsbleka salmon do not spawn until December.