Estimation of fish production rates and associated variances.

Variance estimators for fish production rates are explicitly derived for 2 production models: the instantaneous growth rate and increment summation methods. Statistics for standing stock, mean interval standing stock, instantaneous growth rate, and production: mean standing stock ratio are presented. The use of a jackknife estimator is proposed for estimating the variance of instantaneous growth rate. Comparison of the results from both production models provides a method of cross-validating results. The use of these statistics is illustrated. Brook trout Salvelinus fontinalis annual production in 1969 was significantly higher than combined annual production of brook trout, brown trout Salmo trutta and rainbow trout Salmo gairdneri in 1977.-from Authors