Variance estimates for a dynamic eutrophication model of Saginaw Bay, Lake Huron

First‐order variance propagation is used to estimate variance of model output originating from variances of uncertain initial conditions, parameter values, and external load estimates for a nutrient‐phytoplankton‐zooplankton dynamic eutrophication model of one segment of Saginaw Bay, Lake Huron. Coefficients of variation of model output during summer are not unlike those estimated from measurements. The major source of variance is parameter value variances. The most important parameters, in terms of model sensitivity and variance propagation, are identified by analysis of the predicted correlation matrix. Methods for reducing model output variance are suggested.