Updated 2025-03-21 20:17:01
Lake Huron -> 1.0 Salmonine (Salmon and Trout) -> Lake Trout Condition
Reporting Interval
2018 - 2022
Area
Michigan waters of the main basin
Meeting Target?
Meets
Indicator Trend
No trend
Confidence?
High
1.2.4. Condition of Lake Trout in Michigan waters
Lake Trout condition estimated from a growth index decreased steadily as abundance of their preferred prey, Alewife, also decreased (Figure 1). Recruitment of wild Lake Trout did not occur until after the collapse of the Lake Huron Alewife population in 2003. Since then, condition of Lake Trout has remained positive and stable and followed similar trends in northern and southern Lake Huron populations (Figure 1).
Lake Trout growth index for populations in northern and southern Lake Huron, 1976-2023. The growth index is the predicted length-at-age (log-transformed) from a linear mixed-effect model that included effects for age, calendar year, and year-class (see He et al. 2023, 2024 for details).
Methodology
Length-at-age data were estimated from lake Trout sampled in annual spring gillnet surveys conducted by the Michigan Department of Natural Resources in Michigan waters (10-60 m depth) of Lake Huron. Effects of age, calendar year, and year-class on size-at-age then were estimated using linear mixed-effect models, and the best model was selected based on the Bayesian information criterion (BIC) and Akaike information criterion (AIC).
Other Resources
He, J.X. 2024. Growth stability after the collapse of alewives in Lake Huron and direct size-at-age comparisons between stocked and wild lake trout. Journal of Great Lakes Research 50(3): 102315.
He, J.X., and Bence, J.R. 2023. Systematic changes and random variations: understanding lake trout (Salvelinus namaycush) growth dynamics in US waters of Lake Huron. Journal of Great Lakes Research 49: 737-745.
He, J.X., Bence, J.R., Roseman, E.F., Fielder, D.G., and Ebener, M. P. 2016. Using time-varying asymptotic length and body condition of top piscivores to indicate ecosystem regime shift in the main basin of Lake Huron: a Bayesian hierarchical modeling approach. Canadian Journal of Fisheries and Aquatic Sciences 73: 1092-1103.
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