Eastern Lake Ontario Cisco and Lake Trout
Project Title
Studying spawning behavior of cisco and movement of stocked juvenile lake trout in eastern Lake Ontario
Project Code
Project Duration
November 2016 - January 2020
Project Description
Cisco (Coregonus artedi) were historically an important native forage fish in Lake Ontario. However, as their population size declined in the mid 20th century due to overfishing and competition with non-native prey fish, their functionality as the main forage for native top predator fish such as lake trout, is minimal. In an attempt to better understand the life histories and behavioral patterns of the remnant cisco population in Lake Ontario, we have acoustically tagged adult cisco captured on spawning habitat in Chaumont Bay, in eastern Lake Ontario. Over the sampling period, we will monitor adult cisco spawning behaviors such as location and timing of spawning events and determine seasonal residencies with respect to spatial distribution, temperature and depth. A better understanding of spatial and temporal behavioral patterns in cisco may help Lake Ontario managers successfully restore wild populations of this native forage species. In Lake Ontario, and particularly eastern Lake Ontario, natural reproduction of lake trout (Salvelinu namaycush) and thus, recruitment to the adult population, has been minimal. Extensive stocking programs of juvenile lake trout were implemented in the mid 20th century to aid in restoration of a naturally reproducing lake trout fishery. While adult lake trout survival in Lake Ontario is consistently high, survival of juvenile lake trout is likely the bottleneck to successful restoration of this species. Due to the lack of wild juvenile study samples, this study uses stocked yearling lake trout as a proxy. Stocked juvenile lake trout potentially compete with wild lake trout of the same size and year class, therefore, it can be assumed that they are likely located in the same places and utilizing similar resources. The movement and survival of lake trout post-stocking is poorly understood in eastern Lake Ontario and a better understanding of spatial and temporal patterns of lake trout movements may elucidate better management strategies for both stocked fish and their wild counterparts.