Anglers may be casting for this once lamented species within a decade.
By Jon Osborn
Michigan’s rich, trout-fishing legacy has been celebrated by writers like Harrison, Hemingway, and Traver. And yet, it’s largely a manufactured fishery: the brook trout are true natives, but the browns hail from Germany and Scotland, the rainbows from the Pacific Northwest.
Long before these fish arrived, rivers like the Hersey, Au Sable, and Manistee were home to Thymallus tricolor, the Michigan grayling, and sportsmen were astounded by their numbers:
Take this reference from F.A. Westerman in 1961. “One spring, the grayling were running up the Hersey,” he wrote. “We noted they had some difficulty passing an obstruction in the stream, so we placed a canoe crosswise at that point and caught over 700 one afternoon.”
Like the bison that dotted the Great Plains, and passenger pigeons that blackened the Midwest skies, these so-called “white trout” seemed infinite. But abundance breeds gluttony; word got out, and anglers began catching grayling in staggering numbers. Some were salted-down and sold in nearby cities. For whatever reason, many were pitched on the banks to rot.
Facing onslaught from anglers, logging practices, and unprotected by the rudimentary science of the time, grayling populations faltered. The late-1800s marked an era of sharp decline, with numbers dwindling steadily through the early 1900s. An Otter River angler caught the last documented Michigan grayling in 1936, sounding the death-knell for the species.
Or so everyone thought.
Redemption may be on the horizon, thanks to a collaborative effort known as the Michigan Arctic Grayling Initiative (MAGI). Nicole Watson, a PhD candidate at Michigan State University, along with nearly 50 additional participants—including Minnesota Department of Natural Resources, Trout Unlimited, and various native American tribes—are trying to restore self-sustaining populations of Arctic grayling in their historic range.
“It’s a tall order, considering it isn’t the first attempt to restore grayling populations in Michigan,” Watson said. In fact, there have been three prior attempts to reintroduce grayling: fingerlings were released periodically between 1900 and1941, and between 1958 and1960. More recently, yearlings were stocked between 1987 and1991. In all cases, rapid outmigration posed a major issue, likely because those fish were reared in hatcheries using deep-water wells rather than water from streams where the fish were eventually released.And yet, Watson remains optimistic.
As part of her research at MSU, she hopes to understand early life-stage imprinting to target waters using plasma thyroid hormone analysis and water choice trials.
“Imprinting is what guides salmonids to their home-waters and allows them to spawn in regions where they were hatched,” Watson said. “In previous salmonid studies, elevations in blood plasma thyroid hormone levels corresponded to times when the fish were actively imprinting to the stream water. In the case of grayling, we think this may occur as early as the eyed-egg stage.”
The hope is that young grayling will imprint to their home waters, develop stream residency, and return as adults to spawn.
“Rapid outmigration after introduction, competition with other fish, and predation, are likely reasons why grayling populations haven’t rebounded in prior attempts,” said Watson.
In the past, fall fingerlings (age 0) and yearlings (age 1) were raised in hatcheries that sourced water from deep wells. That may have resulted in the fish imprinting on that specific water-type. When introduced to a stream environment, the grayling may have rapidly out-migrated, searching hopelessly for familiar water.
The state of Montana experienced similar outmigration issues with stocked grayling. To combat the problem Montana Fish, Wildlife and Parks employed remote site incubators (RSIs). Roughly the size of a five-gallon bucket, the incubators incorporate an inflow and outflow system, along with an aerator and egg tray. Following Montana’s lead, Michigan will use RSIs, encouraging fish to imprint to specific water. After establishing proper habitats, a list of suitable streams will be nominated for reintroduction.
A century ago, scientific “data” on the Michigan grayling consisted mainly of journals, newspaper articles, and speculation. Authorities on the era insisted stocked trout were responsible for the grayling’s extinction. Watson says that assessment may be partially true, but feels grayling were equally impacted by dramatic overfishing and habitat loss due to logging.
Watson knows that trout may present challenges to grayling fry, so she’s taking a close look at how the two species compete with each other. While many fish are piscivorous, Watson’s research shows that brown trout prey more heavily upon grayling than do brook trout. In addition, grayling and brook trout have lived compatibly in many streams—prime examples rest north of the Michigan bordering Canada. However, the jury is still out: Watson wants to confirm these assumptions and determine, in fact, which fish community is best suited for grayling reintroduction.
Rumors have circulated widely among the angling community about other, unconventional options, including the mining grayling DNA from dusty, hundred-year-old taxidermy mounts. As intriguing as this cloning-process sounds, Watson says it’s simply not feasible.
“We can’t just ‘Jurassic Park’ old grayling and expect to have a viable population. Genetic diversity is key,” she said, which is why brood stock have been derived from genetically diverse populations in Alaska’s Tanana River.
Michigan maintains a rich trout fishery, but Watson feels it’s time to welcome this native species back home. When that happens is anyone’s guess. Brood stock would take three-to-four years to mature and spawn. However, with any luck, anglers could be fishing grayling within a decade.
John Osborn lives in West Michigan and contributes to a range of publications including Pointing Dog Journal, Retriever Journal, Garden and Gun, Sporting Classics, Upland Almanac, Backcountry Journal, and Trout Unlimited magazine. His latest book, Flyfisher’s Guide to Michigan, was published by Wilderness Adventures Press in 2018
Be Part of the Grayling Effort
Scientific research and specialized equipment, like RSIs and UV sterilizers, are vital to the grayling reintroduction effort. Watson’s biggest challenge has been funding the project, which is supported by the Wenger Foundation and Charles Wilson. For additional information or to donate, visit: www.migrayling.org