By Kevin Naze
Thousands of anglers hoping to strike silver this season are looking to Lake Michigan to provide the treasure.
As they have been for more than half a century, millions of stocked and naturally-reproduced salmon and trout are the targets.
New for 2020, many thousands of fish normally caught on charter fishing trips in April and May were instead “saved for summer” due to COVID-19 restrictions, which were recently lifted.
Dozens of charter captains operate boats in Lake Michigan’s southern basin in early spring in an effort to extend the season, often running two trips a day. That didn’t happen this year.
Whether casting from pier, shore or kayak, or trolling from a charter or private boat, Great Lakes anglers have high hopes of doing battle with chinook and coho salmon, and brown, lake, and rainbow trout.
Fisheries biologists like Jay Wesley of the Michigan Department of Natural Resources (DNR) and Nick Legler of the Wisconsin DNR expect a mixed-bag of species to provide action this year.
In a recent online presentation for the Lake Michigan Committee, Legler noted that the weight of mature chinooks last summer was the heaviest seen since the mid-1980s.
Wesley, Michigan’s Lake Michigan basin coordinator, said the lake’s predator-to-prey balance has improved in recent years – much of it due to lakewide stocking cuts implemented in 2013 – but biologists are concerned that stocking increases could lead to more pressure on an already low forage base.
Substantial natural reproduction of chinooks has been documented, mainly on the Michigan side of the lake. Wild-hatched trout and salmon have also been found in select Wisconsin streams.
For the past three years, all rainbows and lake trout stocked into Lake Michigan have been coded-wire-tagged and adipose-clipped to try to get an idea of just how many wild trout are coming into the system.
Wisconsin is stocking more than three million fish this year, including 1.2 million chinooks and 500,000 cohos. For trout, the new three-year plan calls for 460,000 steelhead, 450,000 browns, 375,000 lakers, 100,000 Arlee rainbows (a near-shore strain), and 50,000 brook trout annually.
Todd Kalish, the Wisconsin DNR’s deputy director of fisheries management, said the state gets lake trout from the U.S. Fish and Wildlife Service and starting this year, plans to get coaster brook trout from the Iron River National Fish Hatchery in northern Wisconsin to raise for release in 2021.
Trout cost more than $1 each to raise in a hatchery, about twice as much as cohos and four to five times more than a chinook fingerling.
Meanwhile – and in addition to stocking and naturally producing millions of trout and salmon in some of its rivers – Michigan is raising Arctic grayling brood stock in an effort to reintroduce the iconic species using new technology after an unsuccessful attempt in the 1980s. If it works, grayling will return to the lake in two or three years after a more than an 80-year absence.
More than 50 partners have already contributed toward the more than $1 million planned for Michigan’s grayling initiative. The Manistee River will be the first water stocked. Check the progress and read all about it at www.migrayling.org
Additionally, you can learn more about the Great Lakes Fishery Commission’s Lake Michigan Committee at www.glfc.org/lake-michigan-committee.php
Lake trout debate
At the heart of the stocking debate are lake trout, a native species all but wiped out in the 1950s by a one-two punch of commercial overharvest and the invasive sea lamprey.
While a welcome bonus for many, lake trout are not typically as prized as salmon, steelhead, and brown trout.
Despite that, the agency charged with native species rehabilitation – the U.S. Fish and Wildlife Service – has stocked more than 50 million lake trout into Lake Michigan since 2004.
More than two-thirds of those go into Michigan waters as part of a negotiated agreement after a U.S. District Court’s ruling in 1979 that an 1836 treaty gave five tribes the right to fish in the Great Lakes.
The United States and the tribes entered into “consent decrees” in 1985 and again in 2000. The 2000 decree was signed by five tribes, the State of Michigan, and the United States.
The 2000 decree outlines management of numerous species, but puts particular emphasis on lake trout and lake whitefish. It expires in August, and closed-door negotiations are already under way for an update. Once in place, the decree can be amended only by consensus among the parties.
Fast forward to 2013, when the four states surrounding Lake Michigan agreed to significant cuts in chinook salmon stockings due to concerns over the forage base, especially alewives. Facing another even more substantial proposed salmon-stocking cut three years later, sport fishing businesses, fishing clubs and individual anglers lobbied for major cuts to lake trout.
The Lake Michigan Committee – senior staff members from the Illinois, Indiana, Michigan, and Wisconsin DNRs, and the Chippewa-Ottawa Resource Authority – eventually agreed that if a state chose to reduce its lake trout numbers, it could get one additional chinook for every 2.3 lake trout cut.
The committee uses a formula known as “chinook-salmon equivalents” that estimates the impact of individual trout and salmon species on the forage base compared to that of chinooks, which are known to target alewives almost exclusively. During a chinook’s lifetime, the formula estimates that one king consumes about as much food as 3.2 cohos, 2.4 steelhead, 2.2 brown trout and 2.3 lake trout.
Charter captain Troy Mattson, who co-owns an 11-boat fleet in Algoma, Wis., said he has a hard time believing data that estimates lake trout eat only about 12 pounds of alewives in a year vs. more than 40 pounds for a chinook.
Mattson said chinooks that survive and aren’t caught and kept by anglers are only in the lake an average of 21⁄2 to 31⁄2 years before spawning and dying. Lake trout, on the other hand, can live for decades. An Indiana state record 37.55-pound laker caught in 2016 had fin clips that indicated it was likely stocked in the 1970s, making it close to 40 years old.
Biologists say while that’s rare, the average lake trout in Lake Michigan might be 10 to 12 years old or more, meaning that over the course of its lifespan it could eat more alewives than a salmon.
Sea lamprey control
Millions of dollars are spent by states and provinces each year in an effort to control sea lampreys, a jawless parasitic fish native to the Atlantic Ocean.
Spawning adults deposit eggs in nests in Great Lake tributaries. Once the eggs hatch, the larvae burrow into the sediment where they spend anywhere from three to seven years filter-feeding on organic matter and macro-invertebrates.
At that point, they migrate to the main lake, where they spend 12 to 18 months feasting on trout, salmon, whitefish, and other species. The adult lampreys kill fish by latching on with a tooth-filled, suction cup mouth, drilling a hole with a razor-sharp tongue and feeding on the fish’s blood.
Lampreys invaded the Great Lakes through manmade shipping channels in the 1920s, and by the 1950s, had nearly destroyed lake trout and whitefish.
The Great Lakes Fishery Commission was formed in 1955 to restore the fisheries.
Scientists first had to discover their complex life cycle, then figure out the best chemical treatment to kill lampreys while leaving the rest of the aquatic life unharmed.
More than 6,000 compounds were tested before settling on one in 1958, and a second one used in small amounts in combination with the first, in 1964.
That chemical control effort led to an estimated lamprey reduction of about 90 percent by the early 1960s, and restocking programs began.
Continued control and monitoring is important, since one lamprey can kill 40 or more pounds of fish in its lifetime. Lampricide treatments, mechanical barriers and electrical barriers are all used as controls.
The program is administered and funded by the Fishery Commission and implemented by two control agents, the USFWS and Fisheries and Oceans Canada.