Every year from April to November, the Michigan Department of Natural Resources is on the Great Lakes, surveying the important and diverse Great Lakes fisheries.
Crews from research stations in Marquette, Charlevoix, Alpena and Harrison Township gather data on fish populations, fish health and the presence and effects of invasive species. It’s vital information that directly informs fisheries management decisions — such as stocking levels or regulated catch limits — and provides data to help gauge the success of past actions.
With surveying for 2024 wrapped up, DNR fisheries biologists are now synthesizing the findings and preparing for next year’s surveys. Interested in what the surveys found? Check out highlights from each research station’s survey efforts.
Lake Superior and northern Lake Michigan
The crew of the research vessel (RV) Lake Char began work on Lake Superior as soon as the ice melted and continued through early November. The Marquette Fisheries Research Station’swork focuses on lake trout, though species studied this year also included lake whitefish and burbot.
Data from the spring 2024 Lake Superior surveys showed a slight increase in adult lake trout populations in nearly all areas. The summer juvenile lake trout survey indicated slight increases in recruitment (reproduction and survival) on the west side of the Keweenaw and Munising areas and a slight decline in all other locations, with stable populations overall. During the field season, 257,100 feet (48.7 miles) of assessment gill net was deployed for these surveys at 123 sampling stations across the lake.
The RV Lake Char surveyed waters around Isle Royale in spring to assess the status of lake trout populations around the island. The crew also conducted surveys in the deepest waters of Lake Superior (and all the Great Lakes) — about 1,320 feet — to survey siscowet lake trout populations. The RV Lake Char crew finished the survey season with lake trout survey work at Klondike Reef, a remote location 40 miles from shore, in October and then surveyed nearshore lake trout spawning reefs near Munising in early November.
Nearshore Great Lakes fisheries assessment work from Upper Peninsula ports involved 10 miles of trawling in Lake Michigan’s Little Bay de Noc and Big Bay de Noc. In addition, over 25,000 feet of survey gill net was used in four locations in northern Lake Michigan (Big Bay de Noc, Little Bay de Noc, Naubinway and Manistique) and two locations in southern Lake Superior (Keweenaw Bay and Huron Bay). Catch data from these fall surveys provide useful metrics for assessing fish community change and populations of species including walleye, yellow perch, smallmouth bass, northern pike, lake sturgeon and invasive Eurasian ruffe.
This winter, the Marquette Fisheries Research Station staff will perform maintenance in preparation for the 2025 field season and process the samples and data collected during 2024. These surveys provided data for collaborations with researchers from Purdue University, University of Wisconsin-Milwaukee, State University of New York-Brockport, Michigan Technological University and Michigan State University.
Charlevoix Fisheries Research Station staff also used small vessels for targeted surveys in 2024. Staff assisted Central Michigan University researchers with scuba surveys of mussel populations in large rivers and continued a multiyear assessment of spawning reefs in northern Lake Michigan. Reef assessments included characterization of habitat quality, deployment and collection of egg-sampling gear, and tagging of lake whitefish with acoustic tags to assess movement and spawning site use.
The 2024 field season for the Alpena Fisheries Research Station and research vessel (RV) Tanner began in April with the annual spring lake trout assessment.
The crew surveyed 14 locations in U.S. waters of Lake Huron from Drummond Island to Port Sanilac to determine the abundance and distribution of both young and adult lake trout. The catch rate of adult lake trout was similar to that of recent years, and most young lake troHARLEBVOIXut (both hatchery-reared and wild-born) continue to be collected in northern Lake Huron.
The RV Tanner once again made its way to the eastern Upper Peninsula for an annual fish community survey in the Les Cheneaux Islands, where the gill net catch rate of yellow perch increased, and other indicators of perch population health were within sustainable ranges.
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