Updated 2023-12-20 21:24:44
Lake Michigan -> 1.0 Salmonine (Salmon and Trout) -> Lake Trout Spring Catch Rate
Reporting Interval
2016 - 2021
Area
Lake Michigan
Meeting Target?
Does Not Meet
Indicator Trend
No trend
Confidence?
Low
1.2.1 Mean number of lake trout captured in spring graded-mesh gill net surveys above 25 fish per 1,000 feet of net
Lake trout (Salvelinus namaycush) was historically the native apex predator in Lake Michigan (Smith 1968), and its population has supported valuable commercial and recreational fisheries. By 1960, overfishing and predation by sea lamprey (Petromyzon marinus) resulted in the extirpation of lake trout from Lake Michigan (Wells and McLain 1973; Holey et al. 1995; Hansen 1999). The primary management actions for restoring the lake trout population have included sea lamprey control and large-scale stocking efforts over the past 55 years. Lake trout management is further guided by objectives and management plans initiated by the Lake Michigan Committee. Management objectives and targets are generally oriented around facilitating development of self-sustaining populations (Bronte et al. 2008; Dexter et al. 2011).
The relative abundance of lake trout based on catch in spring gillnet surveys was below the target of 25 fish per 1,000 feet of net in both northern and southern Lake Michigan from 1998-2021 (Figure 1). Lake trout relative abundance trended upward in both southern and northern Lake Michigan during 2001-2018, whereas relative abundance was stable from 2018-2021 in southern Lake Michigan but declined in northern Lake Michigan (Figure 1).
The broader population level results from the spring gillnet survey remain below the expectation of 25 fish per 1,000 feet of net, and rarely have exceeded 15 fish per 1,000 feet of net. We continue to review characteristics of survey design and implications for population level assessments (LTWG 2022). The aim is to evaluate strengths and limitations of existing practices and implement improvements where needed.
Figure 1. Relative abundance of hatchery and wild lake trout pooled at northern and southern spring lakewide assessment plan sites in Lake Michigan, with a benchmark value of having greater than or equal to 25 fish per 1,000 feet of net.
Methodology
Spring LWAP graded-mesh gillnet survey (see Schneeberger et al. (1998) for details on lakewide assessment plan (LWAP)). The spring survey is conducted when fish are thought to be mixed and provides an estimate of lake trout relative abundance over time.
Other Resources
- Bronte, C. R., C. C. Krueger, M. E. Holey, M. L. Toneys, R. L. Eshenroder, and J. L. Jonas. 2008. A guide for rehabilitation of lake trout in Lake Michigan. Great Lakes Fishery Commission Miscellaneous Publication 2008-01. Available at: http://www.glfc.org/pubs/misc/2008-01.pdf.
- Dexter, J. L., Jr., B. T. Eggold, T. K. Gorenflo, W. H. Horns, S. R. Robillard, and S. T. Shipman. 2011. A fisheries management implementation strategy for the rehabilitation of lake trout in Lake Michigan. Available at: http://www.glfc.org/pubs/lake_committees/michigan/impstr_rehablktrout.pdf
- Hansen, M. J. 1999. Lake trout in the Great Lakes: basin-wide stock collapse and binational restoration. Pages 417-453 in W. W. Taylor and C. P. Ferreri, editors. Great Lakes fishery policy and management: a binational perspective. Michigan State University Press, East Lansing, Michigan.
- Holey, M. E., R. W. Rybicki, G. W. Eck, E. H. Brown Jr., J. E. Marsden, D. S. Lavis, M. L. Toneys, T. N. Trudeau, and R. M. Horrall. 1995. Progress toward lake trout restoration in Lake Michigan. Journal of Great Lakes Research 21(Supplement 1):128-151.
- Lake Trout Working Group (LTWG). 2022. 2021 Lake Michigan Lake Trout Working Group Report. Great Lakes Fishery Commission, Ann Arbor, Michigan. Available at: http://www.glfc.org/pubs/lake_committees/michigan/LTWG_docs/Lake%20Trout%20Working%20Group%20Report%202021.pdf.
- Schneeberger, P., M. Toneys, R. Elliott, J. Jonas, D. Clapp, R. Hess, and D. Passino-Reader. 1998. Lakewide assessment plan for Lake Michigan fish communities. Great Lakes Fishery Commission, Ann Arbor, Michigan. Available at: http://www.glfc.org/pubs/lake_committees/michigan/lwasses01.pdf.
- Smith, S. H. 1968. Species succession and fishery exploitation in the Great Lakes. Journal of the Fisheries Research Board of Canada 25:667-693.
- Wells, L., and A. L. McLain. 1973. Lake Michigan: man’s effects on native fish stocks and other biota. Great Lakes Fishery Commission Technical Report 20.
Contributing Author(s)
- Lake Michigan Technical Committee - Lake Trout Working Group