Monitoring of the salmon and trout stocks in the River Tornionjoki in 2007
The report deals with the monitoring results of salmon and trout stocks in the River Tornionjoki in 2007. The main monitoring methods were electrofishing, smolt trapping, compilation of catch statistics, analysis of catch samples and fish tagging.
Mean densities of both 0+ and older wild salmon parr decreased on the previous year, being 9.4 and 9.3 ind./100 m2, respectively; however, this is slightly higher than the prevailing mean density in the current decade.
A combined analysis of the smolt trapping results and parr density estimates indicates a salmon smolt run of about 800,000 wild smolts in 2007. The smolts of 2007 mostly hatched in 2003. These days, virtually all smolts in Tornionjoki River originate from natural spawning. Wild smolt production has been at an elevated level for the last seven years.
The Finnish salmon catch in Tornionjoki River was 22,000 kg (2,650 individuals) in 2007, two times higher than in 2006. In the current decade, the mean salmon catch in Tornionjoki River has been approximately 19,000 kg.
The natural reproduction of trout has declined in the Tornionjoki River system during the last four years. The bulk of the river catch of sea trout is caught near the river mouth. Sightings of sea trout spawners near the spawning tributaries are still fairly scarce.
Lohi- ja meritaimenkantojen seuranta Torniojoessa vuonna 2007
Ville Vähä, Atso Romakkaniemi, Matti Ankkuriniemi, Kari Pulkkinen ja Marja keinänen
Riista- ja kalatalous.
Selvityksiä, nro 7, 2008
ISBN 978-951-776-617-3 (pdf)
ISBN 978-951-776-616-6 (printed)
ISSN 1796-8895 (pdf)
ISSN 1796-8887 (printed)
Keywords: Tornionjoki River, salmon, trout, parr, smolt, spawning run, river fishing, stock assessment, catch statistics, M74 syndrome
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