Genetic Assessment Methods (GAM)

What is the Problem?

Methods commonly used for estimating the abundance or relative abundance of fish populations, such as depletion estimates, mark-recapture estimates, weir counts, and redd surveys, are often time intensive, costly, and lack precision. Consequently fisheries management or conservation decisions are often made based on a lack of empirical data, empirical data that lack precision, or empirical data that are biased. Therefore, investigations into alternative methods for acquiring data sought by resource managers and policy makers are warranted.

What are we doing?

Genetic-based techniques that are capable of estimating the number of breeders in a population and the effective size of a population are currently available. These genetic assessment and monitoring techniques are also capable of providing information on the genetic diversity and hybridization status of populations. However, these techniques have received limited evaluation; therefore, we are evaluating the efficacy of using genetic assessment techniques for characterizing bull trout populations throughout the state of Oregon. Specifically, we are interested in identifying the sample sizes necessary for providing robust estimates of the number of breeders, genetic diversity, and hybridization status for bull trout populations that differ in abundance, spatial distribution, and hybridization threat.


This information will identify if genetic assessment and monitoring is a time and cost effective alternative to methods commonly used for evaluating management or conservation status of fish populations. Data generated from this project will be directly applicable to development of short-term or long-term genetic assessment and monitoring protocols for bull trout range-wide, and may be used to identify procedures for developing genetic assessment and monitoring protocols for other fishes.

Who to contact?

Mike Meeuwig

Steve Starcevich

Shaun Clements