At Central Michigan University's Biological Station and mesocosm facility on Beaver Island, biologists and students can conduct many kinds of research in a variety of conditions, all at the same time. This is one of three stories about current wildlife studies. The others concern bloody red shrimp, an invasive pest with a foothold in the Great Lakes; and island chipmunks, which are more than just cute faces.
CMU biology students are putting in detective work to help solve the mystery of disappearing lake whitefish.
The species' importance to northern Michigan is undeniable: The popularity of Great Lakes whitefish as a food source fuels a solid commercial fishing industry.
But their numbers are dropping. Younger ones remain plentiful for sure, but the adults are getting scarcer.
State and federal agencies, and the Little Traverse Bay Bands of Odawa Indians, are on a quest for answers. So are students at the
CMU Biological Station on Beaver Island.
They're taking a hard look at juvenile whitefish in particular.
"Somewhere between the start and the end, there's something going wrong," said Gary Michaud, a CMU graduate student from Milford, Michigan, who also works as a fisheries research technician for the Odawa bands.
Tackling the mystery as a team
The adults spawn in November over cobbly, rocky shoals. The young hatch in spring, and as larvae they're carried by currents and distributed in small bays. The juveniles are in deeper water by mid-July.
That means May, June and early July are perfect times for CMU students to take water samples along the Beaver Island shoreline. Each student has a specific task.
Donnie Uzarski, a sophomore biology student from Remus, Michigan, wants to find out what's going on in those little bays when the whitefish still are larvae. He also wants to know which bays give the little guys their best shot at adulthood.
Using a 100-foot net, he's taking samples at a few different sites this summer. One is along the shoreline near the biological station. Another is a short distance away at a campground.
"Despite their close proximity, they're very different sites," said Uzarski, whose father is Don Uzarski, a CMU biology professor and the biological station's director.
"This one here is more protected, it's shallower, it's sandy, it's warmer. The one down south is deeper, rockier and colder. It's exposed to more currents."
Further samples will show the bays with the largest and most numerous juvenile whitefish. They will be the nursery sites researchers hope to build on.
Connor Kowalke, a senior biology major from Romeo, Michigan, is piecing together the relationship between the whitefish and the round goby, a tiny fish that invaded the Great Lakes in the late 20th century.
The relationship is competitive, but how? Kowalke said he wants to learn if the two species are chowing down on the same invertebrates, or if the goby have acquired a taste for the whitefish young.
"Adult lake whitefish have been known to consume round gobies," he said, "so I think it'd be interesting to see if adult round gobies consume juvenile lake whitefish, because that means they're competing with each other at different stages of life."
Kowalke checks his nets and notes the most abundant invertebrates, such as insects and small crustaceans. He also examines the guts of both fish.
A long relationship
Does the whitefish decline constitute a crisis? Michaud says no — at least for now.
"It's a concern," he said. "I think most native species here should be a concern to a lot of people."
To the tribes of northern Michigan, "fish are life," Michaud said. The whitefish issue is of particular interest to them.
They even have cultural importance, he said. A major food and income source for native peoples over thousands of years, whitefish remains have been found alongside the dead in Indian burial grounds.
"The tribal fishermen want their grandkids to be able to fish these fish," Michaud said. "They want grandkids' grandkids to fish these fish."