Status of salmon stocks in rivers Teno and Näätämö

River Teno

The salmon stock in the River Teno is one of the largest in the world. Yearly river catches fluctuate between 70-250 tons and between 15 000-60 000 individuals. Based on the exploitation rate of radio-tagged salmon (40-70%) it is estimated, that in the top years some 120 000 salmon ascend the river. During the years 1972-2007 no declining trend in the catch has been observed.

The estimated total salmon catch (Finland + Norway) of the River Teno in 1972-2007.

The juvenile densities follow the variation in the catch (=spawning stock). For example, the strong spawning stocks during 2000-2003 can be seen as high densities of 0+ salmon in years 2001-2004. Overall, no declining trend in juvenile densities has occurred during the study period between 1979 and 2007.

The estimated mean densities of salmon fry (0+) and parr (>0+) in the River Teno mainstem in 1979-2007.

The life-history traits of the river Teno salmon are extremely diverse. Salmon parr spend their first 2-8 years (usually 3-5 years) in freshwater followed by the smolt migration to sea. At sea the salmon spend 1-5 years before migrating to the river of origin for spawning. After spawning the kelts (spawned adults) over winter in the river before the second sea migration. After an extra year in the sea salmon re-enter the river for second spawning. Overall, close to 100 different life history combinations (river-age + sea-age + additional sea-age after first spawning) can be found from the spawning stock.

Two-year-old salmon parr. Photo: Panu Orell.

The sea-age distribution of salmon is largely variable between years. However, in all years 1-3 sea-winter (1-3SW) salmon constitute the bulk of the spawning stock. The proportion of four (4SW) and five (5SW) sea-winter salmon is usually small. In recent years the numbers of repeat spawners (PS) has increased. During 2001-2005 repeat spawners have constituted 10-20 % of the catch in numbers and 20-30 % in weight. Their contribution to the egg deposition is even higher as the majority of repeat spawners are females. The incidence of farmed salmon escapees in the catch has been low (0,1-0,7%) during the last 20 years.

The sea-age distribution of salmon in the river Teno mainstem in 1972-2007.

The river Teno is one of the most popular fishing areas in Finland with some 7000-10000 sport fisherman visiting the river (on Finnish side) annually. On average they buy c. 25 000 fishing days per season. In addition of the sport fisherman the local indigenous sami people are exploiting the salmon stocks with rod and line, drift nets, gillnets and weirs. In recent years the Finnish and Norwegian catches has been approximately equal. Salmon stock management is based on the bilateral agreements between Finland and Norway, with several fishing regulations in use to protect the salmon stocks of the River Teno.

River Näätämö

The river Teno is one of the most popular fishing areas in Finland with some 7000-10000 sport fisherman visiting the river (on Finnish side) annually. On average they buy c. 25 000 fishing days per season. In addition of the sport fisherman the local indigenous sami people are exploiting the salmon stocks with rod and line, drift nets, gillnets and weirs. In recent years the Finnish and Norwegian catches has been approximately equal. Salmon stock management is based on the bilateral agreements between Finland and Norway, with several fishing regulations in use to protect the salmon stocks of the River Teno.

The estimated total salmon catch (Finland + Norway) of the River Näätämö in 1972-2007.

The juvenile densities on Finnish side have remained on fairly low levels during the study period between 1990-2007. Instead, on Norwegian side juvenile densities have been significantly higher, especially in the 1990-s. The low densities of 0+ juveniles is at least partly due to the lack of adequate sampling sites at or close to the spawning areas in the electro fishing programme.

The estimated mean densities of salmon fry (0+) and parr (>0+) of the River Näätämö on Finnish side in 1990-2007.

The estimated mean densities of salmon fry (0+) and parr (>0+) of the River Näätämö on Norwegian side in 1990-2007.

Like in the River Teno, the sea-age distribution in the River Näätämö is largely variable between years. Normally one sea-winter (1SW) salmon constitute the bulk of the catch, but in certain years 2-3SW salmon occur in great proportions. Four sea-winter (4SW) salmon are caught yearly, but their proportion is negligible. The incidence of repeat spawners (PS) is fairly low and no increase has occurred in recent years, as in the River Teno. Some farmed salmon escapees are caught annually, but their proportions have remained in low (0,0-1,0%) levels.

The sea-age distribution of salmon in the river Näätämö in 1972-2005.

The River Näätämö is highly valued among the sport fishermen both in Finland and Norway. On Finnish side some 600-900 sport fisherman are visiting yearly (1500-3500 fishing days sold annually). The lower reaches of the River Näätämö on Norwegian side are even more popular as some 2000-5000 fishing days are sold yearly. In addition to sport fishermen the local inhabitants are exploiting the salmon stock with gillnets (Finnish side) and seine (Norwegian side). A fish ladder has been built to Skoltefossen (Norwegian side) for helping salmon to pass the waterfall.

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