Seasonal variation in density of juvenile Atlantic salmon in fluvial shoreline habitats of a large subarctic river

The densities of Atlantic salmon fry (0+ years) and parr (1+ years and olde r) in shoreline habitats of the large River Teno watercourse and its tribut ary, the River Utsjoki generally fluctuated considerably, showing an increa se from early summer towards late August and a subsequent decline towards a utumn. The seasonal pattern of variation in density was more distinct for p arr than for fry. In the period between late July and early September, parr density followed a sinusoidal curve, being highest in late August and lowe st in early August and in September. Fry density had a weaker seasonal prof ile than parr, being highest in late August and in early September. Frequen cy distributions of the parr age groups (1 +, 2 + and greater than or equal to3 + years) were mainly independent of the sampling month. (C) 2001 The F isheries Society of the British Isles.