ESR prepress abstract   -  DOI: https://doi.org/10.3354/esr01395

ABSTRACT: Studying population dynamics of freshwater fishes facing extinction is becoming increasingly important to better understand how to protect them in our fast-changing environment. In this study, our objective was to better understand copper redhorse Moxostoma hubbsi (an endangered fish species only found in Quebec, Canada) population dynamics and the effect of stocking to quantify its risk of extinction. We used stochastic population dynamics models based on current survival and reproduction knowledge of copper redhorse. Although our models suggested that extinction probabilities were low, they show that the population is sensitive to random variability and that it is highly likely for copper redhorse population abundance to become low (<250 individuals), making them vulnerable to genetic impoverishment. Also, the low survival of the younger age-classes made them of greater concern for conservation. Our model shows larvae and fry stocked in the Richelieu River contribute to maintain copper redhorse population; however, it also emphasizes the importance of diversifying the current program by stocking 1 yr old individuals to increase population size and help prevent extinction.