Brett van Poorten
My interests include both fish population dynamics and applied fisheries science. My MSc research involved documenting the life history of an unexploited rainbow trout population and examining the response of catch rates and catchability of this population to introducing fishing. Following that, I worked in sothern Alberta to examine the effect of an unscreened diversion channel on the mortality and abundance of fish in the source river. I have since worked for a private consulting company examining the effects of various mining projects at different stages of development on various fish populations in Canada's north.
My PhD research involves examining the effects of interspecific competition on recruitment strength, growth and survival. This work is based on field research conducted on a series of small lakes in the British Columbia interior plateau. The results of this work will include 1) using a data-driven bioenergetics model to estimate variability in growth across years and lakes; 2) a new length-based assessment model to estimate recruitment and abundance by properly estimating the divergence in size-based capture probability between marked and unmarked fish; 3) a new multi-species density-dependent framework for measuring competitive impacts on recruitment across species; and 3) testing this model using data from whole-lake experiments involving wild and stocked rainbow trout in lakes coinhabited by northern pikeminnow. The result of this work will be a critical examination of whether dominance shifts between the two fish species can or has happened in the experimental lakes as a test of the Cultivation-Depensation hypothesis.
Concurrently, I am involved in various projects with collaborators in Canada, the United States and Europe. These projects involve a number of studies involving a new bioenergetics model that incorporates field data to estimate consumption and metabolic rates in a Bayesian framework. This work has been completed on rainbow trout in Alberta, white sturgeon in southern BC, Gulf sturgeon in Florida and two sucker species in Grand Canyon. I have also helped pioneer the use of time-lapse wildlife cameras for use in measuring fishing effort on remote lakes. In addition to using these cameras in interior lakes in BC, I have also used them to monitor the short-term responses of urban anglers to changes in the frequency and intensity of stocking urban lakes. Finally, I have been developing a social-ecological model linking angler satisfaction to stocking rates (as is common in many Eastern European fishing clubs) to examine the development of a stocking-based panacea and the ecological effects of this on the wild population.