Previous research on life history parameters of Dover sole off the west coast of the United States was conducted during the late 1940s and the 1980s.
In this study, we investigated variation in life history parameters of Dover sole off the coasts of Washington, Oregon, and northern California from samples collected during research surveys during 1984-85 and 1990-93.
A total of 4780 Dover sole were collected for age determination during 1984-93 from bottom trawl surveys of the upper continental slope (Raymore and Weinberg, 1990; Parks et al.
Maturity stage was determined for 4490 Dover sole by visual inspection of gonads.
Fish ages were determined by the break and burn method, which is the standard for Dover sole (Pikitch and Demory, 1988), although the method has not been validated.
Bartlett's test of homogeneity of variance was used to test whether variance in length at age varied by sex for Dover sole from ages 3 to 30 years.
Maturation by length and by age were estimated for female (n-934) and male (n-1232) Dover sole with logistic regression (McCullagh and Nelder, 1989).
Geographic variation and sexual dimorphism in the length-weight relationship for Dover sole were investigated by a step-wise procedure among generalized linear models relating the log-transformed length-weight observations to the factors INPFC area and sex, and all possible higher order interactions between these terms.
Variances in length at age of male and female Dover sole were homogeneous.
There was sexual dimorphism in growth of Dover sole when samples were pooled across areas.
We found that growth of male Dover sole differed between the Columbia area and the combined Vancouver, Eureka, and Monterey areas (Table 3) and that male growth curves from the Vancouver, Eureka, and Monterey areas were not statistically distinguishable.
Similarly, we found geographic variation in growth of female Dover sole by area (Table 3).