Figure 5. Relationship between the average length increment
from age one to four years (mm·1-4 years-1) for the
different cohorts of perch and a) summer water temperature (three-year
moving-average, SMA), b) relative density (three-year moving-average,
CPUE) with solid lines representing the multiple linear regression model
results (predictors centred and scaled). c) The relationship between age
at maturation (A50, given by logistic regression) and average length
increment from age one to four years for the different perch cohorts
from 1998-2013, with the solid line representing the linear regression
model and shaded area depicting the standard error of the model. NB.
Lakes were pooled in the linear regressions because no significant
difference in the slope between lakes were detected.