Quantifying long-term population growth rates of threatened bull trout: challenges, lessons learned, and opportunities.

Temporal symmetry models (TSM) represent advances in the analytical application of mark-recapture data to status assessments. For a population of char, we employed 10 years of active and passive mark-recapture data to quantify population growth rates using different data sources and analytical approaches. Estimates of adult population growth rate were 1.01 (95% CI = 0.84-1.20) using a temporal symmetry model (λTSM), 0.96 (0.68-1.34) based on log-regressions of annual snorkel data (λA), and 0.92 (0.77-1.11) from redd counts (λR). Top performing TSMs included an increasing time trend in ‘recruitment’ (f) and changes in capture probability (p). There was only a 1% chance the population decreased ≥50%, and a 10% chance it decreased ≥ 30% (LMCMC). Size structure was stable; however, the adult population was dominated by small adults, and over the study period there was a decline in the contribution of large adults to total biomass. Juvenile condition decreased with increasing adult densities. Utilization of these different information sources provided a robust weight-of-evidence approach to identifying population status and potential mechanisms driving changes in population growth rates.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author