TRAVERSE CITY — Building FishPass will mean the upper and lower Boardman River will be reconnected with West Grand Traverse Bay for the first time in roughly 100 years.
That’s a major change, and fish biologists want to know what’s going on in the river now so they can measure any impacts the first-of-its-kind two-way passage will have. So they’re conducting a number of studies, including looking at how fish move through the river below Union Street Dam in Traverse City now before it’s replaced with FishPass in 2019.
“So the intent is to look at kind of the habitat use and movement of fish in the system below Union Street Dam prior to any work that would go on in FishPass,” Great Lakes Fishery Commission Science Director Andrew Muir said.
Three different technologies let biologists track fish movement, Daniel Zielinski, Great Lakes Fisheries Commission FishPass project lead, said. One is a DIDSON dual-frequency sonar imaging system.
DIDSON image quality is good enough to see fish moving through the river and classify them by size, but not species, Zielinski said. Sea lamprey, the parasitic eel-like creatures, are one exception.
“From the pictures we can say whether it’s a sea lamprey versus any other fish, but we can’t tell walleye from a sucker or anything like that,” he said.
That system was in place in 2017, then in 2018, Zielinski said. Biologists remove the system each year when the Michigan Department of Natural Resources put up screens at the Boardman Weir, now in place.
That weir, just north of Front Street, stops salmon or any other fish from getting upstream. The DNR tracks how many salmon it collects there each year, which Zielinski said those numbers are useful for the fish movement study.
There’s also a set of antennas at various points in the river to monitor tagged fish, Zielinski said. One set picks up radio telemetry tags’ transmissions. Another scans for passive integrated tags.
Radio telemetry tags are pricey — as much as $300 a tag, Zielinski said. They’re being implanted in up to 100 larger-bodied fish like walleye, white suckers, rainbow trout, smallmouth bass and common carp.
Biologists will tag up to 300 fish with the $2-apiece passive integrated transponder tags, Zielinski said. These rice grain-sized devices are similar to what veterinarians implant in pets. They don’t actively transmit, but they can last for several years.
“Those are going in essentially any fish that’s large enough to safely receive a tag and not impact its swimming ability,” he said.
FishPass will be an adaptive structure, and scientists can change how it operates as assessment data reveals the impacts of more fish moving upstream, Muir said. They’ll decide which species to pass and how many of each species based on collected data.
“That is why we’re doing these monitoring programs, because if we detect changes in a positive way, that’s good. If we detect changes in a negative way, that’s bad,” he said. “Then that will allow us to modify the number of species or which species are passed.”
The movement study is one of several to establish baseline data and then track the changes before, during and after FishPass is built, Muir said.
Kelly Robinson, an assistant professor with Michigan State University’s Department of Fisheries and Wildlife, will lead another study considering the consequences of reconnecting the river. It’s still in the planning phase, but so far the idea is to ask locals with an interest in the Boardman about their objectives and values for the river.
Those desires, coupled with some predictive modeling to forecast impacts, can inform the decisions behind which fish to allow upstream, Robinson said.
“The most important part of this is to help us bridge the science with the values of the community in which they’re working,” she said.
Some anglers are concerned over how migratory fish could compete with native brook trout and resident brown trout. The Adams Chapter of Trout Unlimited released a study showing juvenile steelhead, or migratory rainbow trout, can hurt survival and growth rates for young brook and brown trout.
The DNR is working with the Grand Traverse Band of Ottawa and Chippewa Indians to decide which fish species will pass through FishPass, and Adams Chapter President Steve Largent said the study further supports the chapter’s position that steelhead don’t belong in the upper Boardman.
Brook Trout Coalition President Mike Coonan said the group also doesn’t want steelhead too far upstream. He’s hoping the group can comment for Robinson’s study, and he supports all the other scientific work going on as well — so long as it doesn’t involve passing steelhead upstream.
“I think we’re clear that we support the connectivity of the river and we oppose invasive species, including steelhead and salmon,” he said.