Updated 2023-12-08 13:49:15
Lake Ontario -> 3.0 Deep Pelagic And Offshore Benthic Zone Goal -> Whitefish
Reporting Interval
2014 - 2019
Area
Meeting Target?
Does Not Meet
Indicator Trend
No trend
Confidence?
High
Increasing populations of Lake Whitefish across a range of age-groups sufficient to maintain self-sustaining populations and increasing spawning populations in the Bay of Quinte and eastern Lake Ontario
Lake whitefish abundance has not increased in the eastern basin of Lake Ontario and no evidence of the re-establishment of other spawning populations has been documented, therefore, the indicator has not been met.
Average abundance decreased from the previous reporting period (2008-2013) by 43% from a catch per gillnet of 0.35 to 0.2 (Figure 2). Recruitment remained very low in the current period for both the Bay of Quinte and Lake Ontario spawning populations indicated by catches of age-0 Lake Whitefish in bottom trawl towes (Figure 1). There is no evidence that the indicator for Lake Whitefish will be met in the near future.
Figure 1. Catch of age-0 Lake Whitefish per bottom trawl tow in the lower Bay of Quinte and eastern Lake Ontario, 1992-2019.
Figure 2. Catch per standardized gillnet (fish per net) of Lake Whitefish in Ontario waters of the eastern basin of Lake Ontario, 1992-2019.
Methodology
Catch per unit effort (CPUE) was calculated for gillnets set overnight during the summer (June-August) in eastern Lake Ontario in Ontario waters. A unit of effort was standardized to represent 1 gillnet gang of 10 monofilament mesh panels (mesh sizes ranging from 1.5-6 inches) each 15.2 meters long and 2.4 meters high. Six depth stratified sites (Melville shoal, Grape Island, Flatt point, Rocky Point, Brighton and Wellington) ranging from 7.5-27.5 meters and two fixed sites (EB02 and EB06) were used. Mean CUPE was taken across sites and areas before being averaged by year. Detailed information can be found in Ontario Ministry of Natural Resources, 2022.
Recruitment was assessed by calculating catch of age-0 (young of year - YOY) per standard bottom trawl tow. Bottom trawling occurred in the lower Bay of Quinte at the Conway site (30 meter) and in the eastern basin at site EB03 (21 meters). Sites were visited in late summer and fall with four replicate trawls conducted during each visit. Detailed information can be found in Ontario Ministry of Natural Resources, 2022.
Other Resources
Ontario Ministry of Natural Resources and Forestry. 2022. Lake Ontario Fish Communities and Fisheries: 2021 Annual Report of the Lake Ontario Management Unit. Ontario Ministry of Natural Resources and Forestry, Picton, Ontario, Canada.
Hoyle, J.A. 2005. Status of Lake Whitefish (Coregonus clupeaformis) in Lake Ontario and the Response to the Disappearance of Diporeia spp., in Proceedings of a workshop on the dynamics of Lake Whitefish (Coregonus clupeaformis) and the amphipod Diporeia spp. in the Great Lakes. Great Lake Fisheries Commission technical report 66.
Contributing Author(s)
- S. Beech - Ontario Ministry of Natural Resources and Forestry
- E. Brown - Ontario Ministry of Natural Resources and Forestry