Improved Method to Estimate Sea Lamprey Wounding Rate on Hosts with Application to Lake Trout in Lake Huron

摘要

To better estimate wounding rates on hosts of sea lamprey in the Great Lakes, we developed methods to fit a logistic model for the mean number of wounds per host as a function of host length. We applied these methods to the number of wounds (the sum of type-A-1 to A-III marks on hosts collected in spring) on individual lake trout collected by surveys and by a commercial fishery in three regions of U.S. water of Lake Huron from 1984-2000. Wounds per fish were assumed to follow a Poisson distribution, and a number of models were examined using maximum likelihood techniques. Parameters were allowed to vary spatially and temporally, and we used Markov Chain Monte Carlo techniques to evaluate uncertainty in parameter values. By using data for individual hosts and modeling the effect of host length as a continuous function, our method makes more complete use of available data, increases precision, and removes biases in comparison with widely used approaches for estimating wounding rates.