Incubation Discharge and Aspects of Brown Trout Population Dynamics

Abstract

Data from an 11-year study of a population of brown trout Salmo trutta showed that peak discharge at the time of incubation was inversely related to year-class strength (density of young of the year estimated in fall), which suggests that scouring of nests is a source of temporal variation in the density of young of the year. Relationships between cohort (individuals spawned the same year) age-groups provide a clue that discharge-related year-class strength might influence the population dynamics of a year-class over time.