Long-Term Population Dynamics of an Unexploited Lacustrine Brook Trout (Salvelinus fontinalis) Population (Algonquin Park, Ontario)

Long-term studies of demographic processes, such as survival and abundance, conducted in unexploited systems provide unique insight into the natural population ecology of fish but are rarely available. We use historical tagging records of a sanctuary brook trout (Salvelinus fontinalis) population in Algonquin Park, Ontario to investigate the long-term population dynamics of an undisturbed population. Adult brook trout in Mykiss Lake (23.5ha) were surveyed and tagged biannually (May and October) between 1990 and 2004. Open-population mark-recapture models were used to test the importance of time, season, sex and size on estimates of apparent survival and abundance. Seasonal population growth and recruitment were estimated and compared with large-scale climate indices. Time dependent survival and abundance estimates fluctuated, with distinct periods of increase. Population growth and recruitment were positively correlated with winter NAO and ENSO values, whereas survival was negatively correlated. Seasonally, larger individuals experienced higher apparent survival during winter and decreased survival during summer. These findings provide valuable insights into the natural demography of unexploited brook trout populations, and should help inform sustainable management of inland fisheries.