Upstream migration of adult Atlantic salmon, Salmo salar L., in the River Vefsna, northern Norway

Daily ascents of adult Atlantic salmon ( Salmo salar ) in the Laksforsen waterfall in the River Vefsna were recorded over 3 years. Ascent was correlated to 12 physical and meteorological parameters by multiple regression analysis. Change in water temperature was included in the regression model in all 3 years, and change in river flow was also included in 2 of the 3 years. No other variable was included in the regression model at the 0.05 significance level.