Figure 4. Back-calculated length increment (mm·year-1) for age 1 year (top left), 2 years (top right), 3 years (bottom left) and 4 years (bottom right) perch from Lake Vaggatem (green) and Lake Skrukkebukta (blue) in the Pasvik watercourse dependent on summer water temperature (°C). Points represent the mean, whiskers represent the bootstrapped 95 % confidence interval of the mean, trend line with shading represent linear regression with standard error.