Rapid evolution of genetic and phenotypic divergence in Atlantic salmon following the colonisation of two new branches of a watercourse

Table 3 Evolutionary rate of change in haldanes (h) in length, mass, and sea age at maturity in male and female Atlantic salmon estimated from scale samples collected between 1969 and 1981

River branch	Length (h)		Mass (h)		Sea age (h)
River branch	Males	Females	Males	Females	Males	Females
Austervefsna	−0.060	−0.054	−0.075	−0.071	−0.075	−0.074
Svenningdalselva	−0.086	−0.161	−0.106	−0.187	−0.094	−0.162

Data obtained from scale samples collected in the lower part of Vefsna (where anadromous fish were naturally distributed, i.e., downstream of the Laksforsen waterfall) were used as a proxy for corresponding data prior to the first fish ladder being constructed in 1889