A conditional generalized least squares method for estimating the size of a closed population

In the corrected Leslie-DeLury catch-per-unit-effort method, estimation of the corrected cumulative catches causes the underlying model to be an errors-in-covariates structural model with a nondiagonal dispersion matrix. This violates the assumptions of regression and causes the corrected Leslie-DeLury method to give biased estimates of the population size and its variance. Generalized least squares and a controlled variables design were used to resolve these difficulties, obtain the minimum-variance unbiased linear estimator, and compute unbiased variance estimates. The method was applied to sockeye salmon fingerlings (Oncorhynchus nerka) netted in a hatchery pond. For these data, the corrected Leslie-DeLury method underestimates the standard error of the population size by 41%. -from Authors