Updated 2025-03-21 20:52:44
Lake Huron -> 1.0 Salmonine (Salmon and Trout) -> Lake Trout Recruitment
Reporting Interval
2018 - 2022
Area
Michigan waters of the main basin
Meeting Target?
Does Not Meet
Indicator Trend
No trend
Confidence?
High
1.2.5. Lake Trout recruitment in Michigan waters
Lake Trout recruitment was determined from relative year-class strength (YCS), which was estimated from catch rates of age 5-7 individuals. Year-class strength was significantly higher for hatchery fish than for wild fish through 2003 (Figure 1). Thereafter, YCS of wild fish was slightly greater than for hatchery fish until 2017 when YCS of wild fish began to decline and that of hatchery fish increased (Figure 1). The YCS of wild and hatchery fish combined after 2000 was about one third of previous levels when number of lake trout stocked ranged from 1.5-2.0 million yearling equivalents.
Year class strength of the 1968 to 2018 Lake Trout year-classes estimated from gill net catches of ages 5-7 individuals.
Methodology
Year-class strength (YCS) was based on repeated measures at ages 5-7 for each year-class across years. Note that log scale YCS is not additive, and the average back-transformed YCS for wild and stocked lake trout combined since 2000 was only about one third of the previous level.
Other Resources
He, J.X. 2024. Adult mortality and year-class strength of lake trout before and after alewife collapse in the main basin of Lake Huron. Journal of Great Lakes Research 50(5): 102397.
He, J.X., Honsey, A.E., Staples, D.F., Bence, J.R., and Claramunt, T. 2023. Longitudinal analyses of catch-at-age data for reconstructing year-class strength, with an application to lake trout (Salvelinus namaycush) in the main basin of Lake Huron. Canadian Journal of Fisheries and Aquatic Sciences 80: 183-194.
He, J.X., Madenjian, C.P., and Wills, T.C. 2023. A generalized application of the catch-curve regression with comparisons of adult mortality and year-class strength between hatchery-stocked and wild-reared lake trout in US waters of Lake Huron. Canadian Journal of Fisheries and Aquatic Sciences 80: 1714-1722.
Contributing Author(s)
- Ji He - Michigan Department of Natural Resources
- Jose Bonilla-Gomez & Scott Koproski - United States Fish and Wildlife Service
- Stephen James & Chris Davis - Ontario Ministry of Natural Resources