The demise of alewives and salmon in Lake Huron brought something nobody expected: An explosion of native species. Is Lake Michigan next? And could a more diverse ecosystem offer protection against Asian carp and other invaders?
By Dan Egan of the Journal Sentinel staff
Linwood, Mich. — Ernie Plant's eyes get wide when he talks about how spectacular Lake Huron's salmon fishing was back in the late 1980s, when his dad would take him up north on Friday nights after his high school football games.
They'd spend fall weekends along the shore of the lake chasing the chinook that were chasing the alewives that ran so thick they even teemed in water-filled ditches along coastal roadways.
A Watershed Moment
Third of three parts
Published Dec. 7, 2014
- Sunday: The man with the salmon plan
- Monday: Salmon crowned king, but its reign is wobbly
- Tuesday: A Great Lake revival
"We never had a boat," said the sales manager at Frank's Great Outdoors, a gear and bait shop north of Bay City. "But we didn't need one."
When Lake Huron's salmon crashed a decade ago, Plant, who holds a degree in biology from Northern Michigan University, had no doubt the lake would eventually right itself and the fish would come back.
And fish did return — but they weren't the fish Plant or many others expected.
What has happened in the decade since the crash of Lake Huron's two dominant species — invasive Atlantic alewives and the giant Pacific salmon planted to gobble them up — is a remarkable story of nature's resilience. Efforts by lake managers to sustain the invasive alewives to keep the salmon fishing rolling had, for decades, pushed native species to the fringes.
But when the alewife dwindled and the salmon followed, there was an almost instant surge in native lake trout, walleye, smallmouth bass, chubs and emerald shiners.
"It all happened as soon as the alewives were gone," said Michigan Department of Natural Resources biologist Dave Fielder. "The natives started producing like crazy."
The remarkable result is that today the top of the Lake Huron food chain more closely resembles its natural self than anytime since the lamprey and alewives invaded in the mid-1900s.
"Lake Huron's fishery," said Jim Johnson, a retired biologist with the Michigan DNR, "is more stable and robust in the past four or five years than it has been in a long time."
It has everything to do with the disappearance of alewives, and little to do with Howard Tanner and Wayne Tody's grand salmon plan, crafted after alewives had over-run Lakes Michigan and Huron. Tanner said he was never interested in trying to bring back native species just because they were native. He wanted the best sport fishery he could fashion from the lakes — and for him that meant Pacific salmon.
And that led to managing the lakes in a manner that would preserve the invasive alewives for the salmon to eat.
PAUL A. SMITH
Walleye, a popular sport fish, are native to the Great Lakes and are the largest member of the perch family.
Juvenile walleye rely on zooplankton, insects and other small fish. Adults feed on larger forage fish.
Walleye have already been declared “recovered” on Lake Huron’s Saginaw Bay, where they have hit record numbers even though the stocking program ended in 2006.
SOURCE: GREAT LAKES FISHERY COMMISSION
For years after the alewife invasion, the walleye fishery on Lake Huron's Saginaw Bay was sustained only by hatchery-raised fish. But When the alewife population collapsed, native walleye started reproducing in the wild. Walleye numbers have reached record levels even though the stocking program has been stopped."You wanted the alewife to be alive and healthy. You wanted them there forever," said Tanner. "Maybe not as such a big nuisance, but that was the foundation of what you were trying to build. We didn't want to destroy it."
Some biologists on Lake Huron today are looking at alewives completely differently.
One of them is Fielder, who proudly displays on his cluttered desk a framed "Tanner and Tody Award" received from the state for examining what's happened to Lake Huron's food chain since the alewife collapse.
"If you really want a native fish recovery, you're not going to fully achieve that in the presence of alewives, unless natives are sustained by hatcheries," said Fielder. "And how can you call that a recovered fishery?"
Biologists had long suspected that the massive schools of alewives were trouble for native species; they just didn't know how much trouble until the alewives virtually disappeared on Lake Huron. It turns out alewives are death for the Great Lakes' native fish species in a number of ways. They gobble up the eggs and young of native species and out-compete them for the zooplankton that is the foundation of the lake's food chain.
But alewives also doom lake trout in a manner that borders on subterfuge. Alewives carry high levels of an enzyme that triggers a thiamine deficiency in trout, which causes their eggs to either not hatch or induces deadly development problems in trout offspring.
The thiamine problem has been known for years, but the extent that it was foiling federal efforts to restore lake trout in the Great Lakes was not grasped until the Lake Huron collapse.
The top native predator had been sustained on Lake Huron with hatchery plantings for decades. But since the alewife declines, the trout are again successfully breeding in the wild. Lake managers are considering stopping that hatchery program — something most biologists would have thought improbable just six or seven years ago.
Walleye have already been declared "recovered" on Saginaw Bay, an inlet on the western side of Lake Huron that spans more than 1,000 square miles and was the nutrient-rich incubator for much of the lake's alewife population. Walleye have hit record numbers in the bay even though the walleye stocking program stopped in 2006.
"If an alewife swam into Saginaw Bay, it would have a half-life measured in minutes. I'm serious," said Johnson. "The walleye will just kill them."
It's as if the lake's own immune system is restoring itself.
Invasives aid recoveryThis rise of the natives is, ironically, tied to the wave after wave of invasive species that made their way into the lakes in the decades after the lamprey and alewife infestations.
First came the zebra mussel, carried in by overseas freighters sailing up the St. Lawrence Seaway. Then came its cousin, the quagga mussel. Then came an infestation of a little bug-eyed fish called the round goby, which made its way into the lakes the same way as the mussels, and from the same place — the Caspian Sea basin.
The little goby has become the bane of lakeshore recreational anglers because the fish feast on smallmouth bass eggs and out-compete native species for food. They also are quick enough to nibble the worm off a hook without its owner knowing. Or, worse, they latch on with a tug, and have to be reeled to the surface, stripped from the hook and discarded. Over and over and over.
Yet gobies have emerged as precious in one critical way. Unlike most fish now in the Great Lakes, gobies — with their molar-like teeth — can crack the shells of mussels and gobble up their little bundles of meat. This opens up what would otherwise be a nutritional dead end. Gobies eat mussels. Bigger fish eat gobies.
"Lots of fish eat them," said Jim Baker, a Bay City-based biologist with the Michigan DNR. "They are the right size and there are lots of them. They are about the only way that, in a big way, the energy tied up in mussels gets back into the predator fish."
While these Great Lakes natives remain plentiful in certain parts of the lakes, whitefish populations were affected by the invasion of sea lamprey and commercial over-fishing.
The invasion of quagga and zebra mussels had a significant impact on a tiny shrimp-like organism that was the preferred food source for whitefish. Whitefish have since adapted and are now feeding on mussel-eating gobies.
That includes lake trout, walleye and smallmouth bass. It even includes whitefish, which did not evolve as a fish eater in the Great Lakes. But since the whitefish's preferred food source, a shrimp-like organism, disappeared with the arrival of the invasive mussels, they have turned to gobies, even if they must rip their cheeks to get their jaws around them.
Lake trout are showing a similar tenacity.
"We catch lake trout with their noses all banged up," said Baker, "because they've been digging gobies out of the rocks."
Chinook have demonstrated no such resilience. They are built to feast on schooling fish high up in open waters — fish like alewives — and so far they have not learned how to grub out a living on the lake bottom along with the native predators.
"Those species that can make the switch to gobies are OK," said Fielder, a fellow Michigan state biologist. "Those that couldn't, they're gone. And the chinook couldn't."
The chinook collapse has not come without financial consequences. Economic data shows the top fishing towns along Michigan's east coast have lost, collectively, a minimum of $19 million per year since the collapse. It is reflected in empty marinas and hotels, closed bait shops and lonely harbors.
But that does not mean the fishing is bad.
"Lake Huron does not deserve a reputation for poor fishing," said Fielder. "It's just not the familiar chinook salmon fishing experience."
It has taken several years, but some local economies are hitching themselves to the recovery of native species, particularly around Saginaw Bay.
"A lot more people fish for walleye than chinook," said Plant, the outdoor store sales manager. "It's more economical. The equipment costs less and the boats don't have to be so big because you don't have to go out so far."
Asked whether he'd welcome a return of the alewives and salmon of his memories, Plant paused and looked up at the ceiling of the sprawling bait and gear shop, packed on a Tuesday morning with fishing poles, high-tech sonar fish finders — and customers.
"I don't know," he said after taking a deep breath. "We've adapted."
Tale of two lakes
WISCONSIN'S SALMON STOCKING PROGRAM
Chinook salmon returning to Strawberry Creek from Lake Michigan provide eggs for Wisconsin's salmon stocking program. This video looks at the egg harvesting process that takes place each fall.
On a chilly fall morning, Wisconsin's chinook salmon factory was thrumming along near the Lake Michigan shoreline.Thump. Whoosh. Phst. Squirt. Stir. Bam.
At the head of Strawberry Creek near Sturgeon Bay, the production line started in a man-made pool swarming with hatchery-raised chinook.
These adult fish had spent their youth at a hatchery in fall 2011 and were then planted into a concrete pond at Strawberry Creek in spring 2012 for several weeks so the scent of "home waters" could be imprinted on their olfactory system. Then the gates to the pool were opened and the cigarette-sized fingerlings flitted for the open waters of Lake Michigan.
Two and a half years later, these now log-size beasts have followed their noses toward the Lake Michigan coast, into the man-made Sturgeon Bay Canal, up Strawberry Creek and right into the giant concrete pond of their youth.
Here, on the last day of their lives, a crane scooped them from the pool in writhing clusters. They were dumped into a tub bubbling with a numbing gas and then, one by one, fed down a chute.
Thump — The hammer on the SI 5 M3 Stun Machine delivers a knockout blow to the skull and out the back of the contraption comes a limp chinook, eye cocked toward the clouds with all the life of a button.
Whoosh — Rubber-gloved fishery workers slide the carcass onto a scale where it is weighed, measured for length and identified as male or female.
Phst — Females have their stomachs popped with the needle from a hose hooked to a carbon dioxide tank and are gassed up until their bellies excrete a stream of bright orange eggs into a bucket — about 5,000 per fish.
Squirt — Males are bent and squeezed by an assembly line worker in a manner that shoots their milt into little plastic cups with dart-throwing precision.
Stir — A gloveless technician dumps a cup of milt into a 3-gallon bucket containing the eggs from two females, and then dips his fingers, sterilized by iodine, into the icy concoction and swirls until it foams.
Bam — 10,000 eggs are fertilized.
The crop of soon-to-be-fish — more than 200,000 on this day alone — is then taken by van to a state hatchery where the eggs will hatch in about six weeks. The little fish will feast briefly on nutrients in their egg sacs and be gobbling hatchery pellets by January.
Come April they will have grown to nearly four inches and will be brought back to the concrete pool at Strawberry Creek for a few weeks of acclimation before the gates open and they wiggle along with the current toward Lake Michigan, where they will chase the lake's diminishing alewife population until they return to their concrete box in 2017. Or that's the plan.
Biologists are bracing for an alewife collapse on Lake Michigan similar to what happened on Lake Huron, though this is far from a sure thing.
While Lakes Michigan and Huron are actually two lobes of one giant body of water, connected by the Straits of Mackinac, they are in many ways distinct. Lake Michigan is a more "productive" lake due to the nutrients flowing from its tributaries that yield more alewife-sustaining plankton. The lakes also differ in water chemistry, temperature, depth and spawning habitat.
And while Lake Michigan also is now home to a naturally reproducing chinook population, these fish are not breeding to the same degree they were on Lake Huron before its salmon crash.
Still, both lakes have been so ravaged by invasive mussels that biologists believe the alewife collapse on Lake Huron may be a harbinger for Lake Michigan. It's been a concern for the better part of a decade, but it's become a growing worry.
SURVEYING LAKE MICHIGAN FOR LAKE TROUT
The U.S. Fish and Wildlife Service conducts a lake trout survey on Lake Michigan off Sturgeon Bay annually. This video examines the recent resurgence of the fish.
Lake-wide fishery surveys conducted in recent years show the number of alewives are now less than 10% of what they were in the late 1990s. The surveys also show older and larger alewives are disappearing, which is precisely what happened on Lake Huron just before its collapse, where the combination of too many salmon and too little food meant not enough alewives survived to adulthood.
"It's kind of scary, if you look at what happened on Lake Huron," Nick Legler, Great Lakes fishery biologist for the Wisconsin Department of Natural Resources, said during a break on the final day of this fall's egg harvest at Strawberry Creek.
"That's why we reduced stocking, to try to get the system back in balance."
States bordering Lake Michigan this spring will stock only 1.7 million chinook — about half what was stocked just two years ago and well below the peak of about 8 million in the late 1980s.
The federal government, meanwhile, has been stocking some 3 million lake trout annually in Lake Michigan as part of its native species restoration program that dates to the mid-1960s.
That restoration effort sputtered for decades — until the alewife population started to fade. Now evidence has emerged that the lake trout are finally producing viable offspring. The first hint came a decade ago when underwater cameras revealed clusters of pinky-sized fish on a reef in the middle of Lake Michigan.
But would they survive?
About five years ago, small numbers of larger trout appeared possessing all their fins — an indication of wild birth (hatchery-raised trout have a fin clipped). In the last year, biologists say surveys indicate as many as 50% of the lake trout netted in some areas of Lake Michigan are naturally reproducing.
Federal biologists point to the drop in alewives — and a subsequent healthy rise in thiamine levels in lake trout eggs.
It's no surprise state fisheries biologist fear a salmon collapse. Chinook are what recreational fishermen have wanted — and anglers pay the state fishery managers' bills. Nearly $23 million of the Wisconsin DNR's $25 million fisheries budget comes from fishing licenses and taxes on fishing-related products.
With evidence piling up that what is good for native lake trout is bad for planted salmon, and vice versa, the states and federal government are trying to strike a dicey balance.
"The idea is that you keep enough alewives so you have a chinook fishery but not so many that you don't have natural lake trout reproduction. Well, that's a razor-thin line," said Dale Hanson, a biologist with the U.S. Fish and Wildlife Service. "I don't even know if it's possible."
It wasn't on Lake Huron.
Importance of being nativeTom Matych, a 60-year-old retired crane maker from western Michigan, remembers how, as a child in the 1960s, his nose could tell him when the native perch were running especially thick on the eastern shore of Lake Michigan near Muskegon at certain times of year.
"If you could smell the paper mill, which smelled like rotten eggs, you knew the perch were coming, because the west wind blew in the zooplankton and the minnows, and the perch followed them in," he said. "I mean, people took those days off work."
Matych remembers how people rode the public bus with bamboo fishing poles, and how that bus would stop at a bait shop near the lakeshore and how crowded the pier was and how he felt "10 feet tall" as a 5-year-old when he caught his first perch with his father.
It's an experience he wants to share with his own young granddaughter, but Lake Michigan's perch fishery collapsed in the 1990s.
Populations of this Great Lakes native were severely reduced following the invasion of the alewives in the 1950s. Their numbers on Lake Michigan rebounded by the 1980s, but then went into a steep decline. Commercial fishing for Lake Michigan perch in Wisconsin, except for the waters of Green Bay, was banned in the mid 1990s to try to revive the species, though numbers of adult fish remain extremely low.
Young perch begin feeding on zooplankton and bottom-dwelling insects. Adult perch feed primarily on immature insects, larger invertebrates, and the eggs and young of other fish.
Biologists blame a complex set of factors, including a loss of perch-sustaining plankton tied to the quagga mussel invasion. Matych points a finger straight at their efforts to prop up alewives to protect the chinook fishery.
"I'm not good at being politically correct," he said. "But when they say there is not enough food for perch, what they're really saying is there is not enough food for perch and alewives."
He cites the energy — the number of little fish — it takes to make one big chinook.
"You need 123 pounds of alewives to make a 17-pound chinook, and you need 40 pounds of zooplankton to make one pound of alewives," he says. "That's a whole lot of zooplankton for one fish."
Matych is a pesky advocate for a Lake Michigan perch stocking program, something biologists say may be fruitless, given the mussel-driven decline in plankton and the number of stocked perch it would take for even a small fraction of them to survive long enough to be caught.
But Matych isn't worried only about re-creating the perch fishery. He wants lake managers to change their focus from a system dominated by chinook to one that can sustain as many native predators as possible. He's not just thinking about more species for fishermen to catch; he's thinking about the ecological health of the lake itself.
Matych considers native predators to be the lake's "biotic resistance" to new invasions, noting that species like lake trout, perch, walleye and whitefish all feed on different things at different times in different places.
Big numbers of these fish, he maintains, make the lake more resistant to new invaders such as Asian carp, which are currently held back from Lake Michigan by a leaky electric barrier on the Chicago canal system.
Matych doesn't have a doctorate in fisheries biology. He doesn't have any college degree at all. But he thinks big, like Howard Tanner.
"We want to do the same thing that Tanner did," he says. "But with native predators for the 180-something invasive species that the salmon don't eat."
That 180-plus figure for invasive species in the Great Lakes is actually a tally of all the lakes' non-native organisms, including the salmon that have been stocked. But the gist of his argument is not lost on biologists.
"There is a body of evidence that says having a robust, co-evolved food web helps prevent invasive species' establishment," said John Dettmers, a biologist with the Great Lakes Fishery Commission. "It doesn't guarantee it, but it's something to be considered by managers if they are concerned about invasive species."
Dettmers co-authored a 2012 paper that suggests a post-chinook Lake Michigan may be at hand.
"Fishery managers face an interesting dilemma: whether to manage in the short term for a popular and economically important sport fishery, or to embrace ecosystem changes and manage primarily for native fish species that appear to be suited to ongoing ecosystem changes," Dettmers and his colleagues wrote.
The authors suggested numbers of native predators could be boosted if lake managers shut down the salmon pump Tanner started on April 2, 1966. This could be accelerated, Dettmers and his co-authors wrote, by dosing Lake Michigan with so many chinook that they virtually eliminate the alewives which, in turn, could open the door for a surge in native species.
"Maybe salmon was the right medicine to apply 50 years ago," Dettmers said in an interview. "But maybe there are new treatments available now — native fishes — to help bolster the lake's immune system, if you will."
Gobies the new alewife?
FISHING FOR BROWN TROUT
Brian Settele, who runs Fish Chasers Guide Service, talks about how the Milwaukee Harbor has become a world-class fishery for brown trout.
This tension over doing what's best for the long-term ecological stability of the lakes and what's fun for anglers and profitable for charter boat operators draws into sharp relief the dichotomy of Tanner's legacy.
Tanner is proud to have introduced salmon that created a spectacular recreational fishery, but it's clear he is equally gratified that he built a constituency for the lakes. The ecological health of the world's largest freshwater system, he maintains, is largely dependent on having fish in them that people want to catch.
The problem is he doesn't think the native species can do that job. He is encouraged by the surge of naturally reproducing lake trout, but is dubious it will lure people onto the lakes.
"I've never been against lake trout," Tanner said. "I'm just not very enthusiastic about lake trout. My own experience is lake trout aren't a lot of fun to catch, and I doubt if the charter boat captains can sustain a fishery on lake trout."
He calls trolling for walleye "about the most boring thing you can do."
"Like bringing in a wet sock," he says.
University of Wisconsin-Milwaukee biologist John Janssen has bristled against this chinook-first mentality during his own 40-year career on Lake Michigan.
He calls Tanner's idea to convert an alewife infestation into a popular and profitable salmon fishery a "brilliant" decision — for its time.
PAUL A. SMITH
While not native to North America, brown trout have been widely stocked across the continent for more than a century. Great Lakes brown trout tend to stay near shore in waters less than 50 feet deep, which makes them an ideal gamefish for shallow bays.
While not native to North America, brown trout have been widely stocked across the continent for more than a century. Great Lakes brown trout tend to stay near shore in waters less than 50 feet deep, which makes them an ideal gamefish for shallow bays.Now, he said, it's time to view gobies in a similar way — as sustenance for the fish best suited for the ecological changes wrought by the recent round of invasions. These species include natives like lake trout and walleye, as well as exotic brown trout, which have been stocked in the lake for more than a century but also are naturally reproducing in some tributaries.
To treat these sport fish as if they were a noxious species like carp, Janssen said, is to risk alienating a new generation of anglers — the very people who will be most motivated to value and protect the lakes in coming decades.
"There is nothing carp about brown trout," said Janssen, who grew up fishing for wild browns in western Michigan near the very waters where Tanner planted that first class of Pacific salmon. "But some of the chinook fishermen treat them as carp."
Janssen said this tension came to a head at a recent meeting with charter boat captains and other chinook boosters who railed against a plan to restore walleye along the Lake Michigan shoreline. Their fear was that it could put a dent in their chinook catch.
"The problem," the 66-year-old Janssen said, "is you guys are all old. I'm old. We're all going to be dead pretty soon. The big issue is the 12-year-old on the bike.
"What's he going to be catching?"
A new dayA generation ago, Brian Settele was that 12-year-old, rolling his Schwinn 10-speed down the Oak Leaf trail from Glendale to the Milwaukee harbor with fishing poles lashed to the handlebars.
His parents were going through a divorce and he found sanctuary along the Milwaukee waterfront, relishing his summer mornings by reeling in perch and the odd salmon that drifted into the harbor.
Today Settele is a licensed captain running charters out of McKinley Marina. He'll chase chinook if that's what the customer wants, or if they are really biting. He says there is nothing like it.
"They will grab your line and pull it out a football field's length in a matter of seconds," he said. "The best way to explain what it feels like to have one on your line is to imagine standing on an overpass of Highway 41 and having a car bumper down below grab your lure."
The idea that this cultural thrill could disappear has Tanner dismayed.
"Right now I'm very worried about Lake Michigan. It's on the same course as Lake Huron," he said. "The quagga is the culprit. There isn't any question about that. I'd hope for the demise of the quagga mussel, but I can't produce that demise, nor can anyone else."
Settele is learning to make a living despite the quagga infestation by focusing his business on brown and lake trout — two species that keep the clients rolling in.
One recent customer was first-time fisherman John Egan, age 8. His dad does not fish. Neither does his 75-year-old grandpa, both of whom were along for the ride on a frigid, predawn Oct. 17.
John Egan, 8, son of Journal Sentinel reporter Dan Egan, with fishing guide Brian Settele and the first fish John has ever caught, a brown trout, on Lake Michigan this fall.
The water was so black it was invisible as Settele steered his boat through the north gap of the harbor breakwall into the early morning swells. Not long after a flaming orange sun popped on the horizon, a reel whirred and Settele yelled for somebody to grab the bouncing rod.
John scurried up and snatched it. He felt the line tug somewhere deep below the gray-green waves and began to crank the reel.
You could see in the wrinkles of his nose and the creases around his eyes that he wasn't struggling so much as soaring. It's an expression he doesn't have when playing computer games or even chasing a soccer ball.
After a couple of grimacing minutes, his eyes popped and jaw dropped as a freckled three-pound brown trout broke the surface.
It might have been a scrawny thing when compared to one of Tanner's Pacific beasts.
But it was John's fish, caught on John's lake.
And the hook was set.
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