Mean Smolt Age Estimation and Under-Aging Bias of Nass River Steelhead Populations

In the Nass River watershed, juvenile and adult steelhead scales were collected to summarize the mean smolt ages for major summer and winter steelhead populations, and to investigate the lack of the first-year annulus formation which results in under-aging bias. The mean smolt age and potential aging biases were investigated because it was an influential parameter to the Nass River steelhead production model.