Estimating Growth Parameters for Pacific Halibut from Mark–Recapture Data

Abstract

The parameters in the model L(t) = αtβ were estimated for each fish from mark and recapture lengths. The individual estimates of the parameters were combined to give minimum variance unbiased estimates for the population parameters lnα and β. The age-specific lengths of halibut were found to fit a lognormal distribution; hence, the model was fitted to the median of the lengths instead of the mean. The median of the estimator [Formula: see text] is equal to the population median fork length at time t. In this sense the estimator is "median unbiased." As an example of the method, a growth curve is fitted to a group of halibut born between 1961 and 1965 and recaptured in the Yakutat region.Key words: Pacific halibut, growth, estimation