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Saithe in the North Sea and Skagerrak
Saithe in the North Sea and Skagerrak
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Saithe in the North Sea and Skagerrak

Saithe occur both in the open ocean and in the benthic environment at depths from 0-600m. Young fish form schools in the upper layers of the water column, while mature fish inhabit deeper waters. They may swim long distances in search of food.

 

Saithe spawn in the North Sea in the area west of Shetland to Tampen and Viking banks during February-March at depths ranging from 150 to 200m. Their eggs float in the upper layers of the water column. Larvae initially extend south along the western edge of the Norwegian Trench, and then are carried with coastal currents in large whirlpools formed by southbound Atlantic water and the northbound coastal currents.

Saithe fry are first observed on the west coast during April-May each year. They are most abundant from Utsira to Stadt, but occasionally move along the coast to Skagerrak, especially when strong year classes are produced.

They initially inhabit areas close to shore, but eventually move out to deeper water. Their main food items in the early years are various plankton organisms, particularly copepods and krill; but fish larvae and fry may also be on the menu. When saithe become 3 to 4 years old, they often are in poor condition during spring after a long winter. This is evident in their livers which appear small and reddish. Most of the year class moves across the Norwegian Trench into the North Sea, where krill continues to be a substantial part of their diet; however, Norway pout, herring, and other fish species become increasingly important.

Saithe in the North Sea grow faster than saithe north of 62 ° N, and reach sexual maturity at a younger age. They are recruited to the fishery at the under mountains by the coast, and by age three they have reached 35-40cm in length. They become sexually mature between four to six years of age, and approximately 50cm in length.

In summer, saithe are found over the entire North Sea plateau from approximately 57° N to 62° N, but in winter they are concentrated on spawning grounds west of Shetland and between Shetland, Tampen, and Viking Bank. Juveniles are concentrated along the western edge of the Norwegian Trench — especially around the Statfjord oil field, Egersund Bank, and areas southeast.
Also during summer, the largest densities of saithe are found at edges of the North Sea plateau. It is worth noting that very few one and two year old saithe are found in the North Sea. This means that North Sea saithe are not subject to as much discarding of undersized fish from catches as other demersal species in the North Sea. However, discarding of saithe may occur for other reasons.

Saithe is an Atlantic Ocean species. Populations occur in the North Sea and west of Scotland, in waters surrounding Faroe Islands and along the Norwegian coast north of 62 ° N, and in waters adjacent to Newfoundland and Canada. They may occur as far south as the Bay of Biscay. Tagging studies have shown occasional mixing between different populations in the eastern Atlantic.

 

Facts about Saithe in the North Sea, Skagerrak, and West of Scotland

Latin name: Pollachius virens
Family: Cod family (Gadidae)
Maximum size: 130 cm and 22 kg
Lifespan: can become 23 years
Distribution: North Sea / Skagerrak
Spawning area: Edge of the Continental Shelf from west of Shetland to Viking Bank
Spawning season: February to March
Diet: Juveniles eat mainly krill. Adults eat mostly fish.
 

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