Alewives: The trouble they cause and the salmon that love them

Pacific salmon are an economic draw for the Great Lakes.  But they thrive on alewives, an invasive species tough on native fish.

Pacific salmon are an economic draw for the Great Lakes. But they thrive on alewives, an invasive species tough on native fish. Image: Great Lakes Fishery Commission.

By Jeff Gillies, jeffgillies@gmail.com
Great Lakes Echo
Sept. 3, 2009

Editors note: This is the second of three stories in a series about the challenges of managing non-native fish in the Great Lakes.

Pacific salmon, the big money species in the multi-billion dollar Great Lakes fishery, need a feast of alewives to thrive.

But alewives are an invasive species that harm lake trout, a native fish that biologists have been trying and failing to re-establish for decades.

Alewives keep lake trout down in two ways, said Mark Ebener, fish assessment biologist with the Chippewa Ottawa Resources Authority.

The first is simple: Alewives eat baby lake trout.

Lake trout are slow growers and make fine fish food for alewives for a month or two after they hatch, said Charles Madenjian, a fishery biologist with the U.S. Geological Survey’s Great Lakes Science Center.

Size isn’t the only problem. Because they evolved before the alewives invaded the Great Lakes, lake trout don’t know how to dodge an attacking alewife.

“When it comes to avoiding alewife predation, they’re not that bright either,” Madenjian said.

Lake trout also lay eggs in the middle of the lakes where alewives can easily scarf them down. That’s unlike salmon that lay their eggs in streams and rivers to protect their young.

The other way alewives knock down lake trout is that they create a vitamin deficiency that kills newly hatched fish.

Alewife tissues contain a chemical that breaks down thiamine, an important vitamin for the development of young fish and eggs. The chemical can also break down thiamine in fish that eat alewives, like lake trout. When lake trout eat too many alewives, their eggs hatch, but the larvae die.

“There definitely appears to be this strong linkage that everybody’s pretty much in agreement with,” said Jim Dexter, Lake Michigan basin coordinator for the Michigan Department of Natural Resources. “When the thiamine levels get too low because lake trout are eating alewife, that inhibits the reproductive capacity for lake trout.”

Though the reason isn’t clear, the thiamine-busting effect hits some species harder than others. It doesn’t seem to hurt the Great Lakes’ Pacific salmon much at all, Madenjian said.

And while the lake trout aren’t the hardest hit species, they’re hit hard enough, especially when the effect is combined with alewives preying on young lake trout, Ebener said.

“So the alewives, besides eating the larvae of native species, also disrupt the biochemical processes of native lake trout so that lake trout reproduction doesn’t happen,” he said.

And if lake trout aren’t reproducing, then the Great Lakes will remain without their historical top predator. And that isn’t a stable ecosystem, said Jason Stockwell, a fishery biologist formerly with the U.S. Geological Survey’s Lake Superior Biological Station.

Lake trout and other native species evolved in the Great Lakes and are built to take advantage of them, he said.

Lake trout find food in the deep water in the middle of the lakes and the shallow water near shore. That makes them more versatile than salmon, which stick to shallow water. A rehabilitated lake trout population would be less prone to collapse than salmon because the native trout don’t depend on one source of food.

“Native fish rehabilitation would get the system back into its most efficient and stable state,” Stockwell said. “Otherwise, there’s a continual need to keep stocking salmon.”

For many recreational fisherman and state departments whose budgets depend partly on fishing licenses, an unending salmon stocking program wouldn’t be a bad thing.

Great Lakes recreational fishing generates between $4 billion and $8 billion every year, said Dan Thomas, president of the Great Lakes Sports Fishing Council. Most of that comes from salmon fishing.

“Just by the numbers of caught fish that are reported, it could easily be 70, 80 percent,” he said.

Salmon are a more exciting target than lake trout, he said. They swim fast and jump high; a deep-water lake trout sit at the bottom and tugs on the line.

“It’s like drag racing with a Corvette versus a Model T,” Thomas said.

But some anglers still enjoy fishing for lake trout, including Thomas. But if the state agencies abandon salmon stocking to focus on lake trout restoration, revenues from licenses will drop and the states will start shedding employees.

“When your budget is in decline, something has to give,” he said. “It’s all simple economics.”

Part three: Lake Michigan walks the alewife tightrope

33 thoughts on “Alewives: The trouble they cause and the salmon that love them

  1. Not sure what your trying to say. The Michigan DNR stopped stocking salmon (mostly) and brown trout all together because the native fish that are coming back with the loss of the alewives are eating them faster than they can plant them. Never said it wasn’t fun to catch a salmon, my point is what’s best for the lakes, not so you can have a tournament. Chinook require alewives dominant, alewives eat larval native fish, Perch walleye etc… and the same zooplankton all fish need and that we don’t want Asian Carp to eat. A compromise is switch to steelhead not native but not dependant on alewives to survive. Native fish have adapted to the new invasive food, chinook have not, cannot according to experts, pretty obvious that’s true. Intentionally destroying the natural ecosystem/native fishery for one non-native fish is just wrong. Could you live with catching steelhead to save the lakes? Plus you get the Perch and walleye back! People like catching salmon, but the cost is too high.

  2. tom M
    not shur were you hear that lake huron stoped but you are wroung cause us canadians love are trout and salmon that is why we have are derbys that the one on lake huron had 2000 boats and 4000 people enter the derby right and that is not including the salmon derby in owen sound ontario that had 8000 people enter right you need to get youre fax strate i think.

  3. Pingback: Alewife harvest in lake Michican | Invasivore.org

  4. Perhaps if alewives would quit hogging the zooplankton and eating larval fish maybe they could get thier one spawn in. If you are right then we should be stocking every Perch we can, walleyes as well, never run out of food, never have to worry about balancing “predator prey” like salmon if alewife experiment. You wont find any biologist connected to the salmon that will endorse using any predator for any invasive we got too many (predators) now, and any increase in native fish threatens the alewife salmon plan. However I once asked a biologist what keeps Gobies in check in thier native range (Black Sea) his response was predators, pollution, and disease. So we’re cleaning up pollution, waiting for any invasive to overpopulate and starve (thus disease) is just silly. So that leaves predators, “A primary funtion of aquatic systems” but you say useless to try. Why? Because you can’t stock salmon in a healthy native fishery, and since it seems catching a salmon is your only claim to fame (That’s sad really) we can’t use predators that control what’s what in a lake any lake, but it wont work here, according to you. You’re all wet scoop, I’m being polite.

  5. Walleyes, perch, smallmouth bass, largemouth bass, whitefish, northern pike, muskies, brown trout, burbot and bowfin are among the many fish that eat multiple size classes of gobies, and what good has it done? Cormorants feast on ‘em. So do white pelicans, and mergansers. What good did it do when the first gobies arrived far fewer in number than today? There are just too many and they’re far too prolific.

    No comparing alewives (spawn once a year and young/adults easily found schooling in open water and also killed in sharp temperature changes, not enough food when young, etc.) with gobies (spawn up to six times a year, bury in muck or hide in rocks by day, forage at night, unending food supply in mussels).

    Everyone else is wrong? Find me EVEN ONE real scientist who says that if there are enough yellow perch in the Great Lakes, they’ll wipe out the gobies. You won’t find one because they know it’s not possible.

  6. Just for fun I googled (round goby size)seems everybody but you knows gobies can run from 4 to 10 inches. But one study caught my eye: Size preferences and behaviors of native yellow perch foraging on invasive round gobies:, the first line in the abstract is “Predation is one of the primary mechaisms that shape aquatic food webs” Predation a primary? It also says adult perch will eat 6 size classes of gobies, all good. They want $31. bucks to read the whole thing so I wont be doing that. So we have a predator, increasing predator pressure would decrease gobies, but it wont work according to scoop, everyone else is wrong. When the lakes were 90% alewives (Too Many ?) they planted predators. Now they say too many P R E D A T O R S will wipe out the alewives? But this primary function of any aquatic ecosystem wont work on gobies? Sorry Scoopy can’t write no slower. Trophy gobies is very old news anyway.

  7. Woods n waters news but they don’t post all thier articles on thier website, besides I din’t know how to paste, always winds up somewhere? Doesn’t matter go to Grand haven see for yourself, we ran over 23,000 gobies thru the goby assault contest Muskegon plenty of 8 to 10 Goby Dick (biggest) was 10 inches $500. bucks for biggest. According to the 2008-2010 action plan for Lake Huron goby numbers have declined in recent years? Change in predators? Nah can’t be gobies spawn too much, we’re all doomed, gobies will be coming out of the faucets pretty soon. Scoop you and the DNR are running out of lies, look at Green Bay, Tournaments, look how many fish we stocked blah blah blah…. Don’t look at whole picture, don’t look at the real problem, save the alewives! Enough already.

  8. Link to the published photo, please, and yes, please do catch those giant gobies, since even the DNR research nets haven’t found one anywhere close to that size.

    Tell me Tom, how could gobies ever gain a foothold in predator-rich environments like Green Bay? How could the first “few” gobies that hitchhiked make it out alive with millions of bass, perch, walleyes, pike, muskies, burbot, brown trout, whitefish and cormorants to feast on them? If those first few hitchhikers made it, what chance do we have against millions of gobies that spawn six times a year? I’ll give you the answer: there is no chance.

  9. I know what I saw, I’ve seen more gobies than most should have to. Your right tho gobies are supposed to be only 4-5 inches, but they’re growing huge on the food here, they eat the soft food first, like diporeia before zeebs. Years ago I caught 80 gobies in just over an hour, most were bigger (and as fat as) an 8 inch flashlight. The picture of the pile with flashlight was published twice. I’ve been asked to catch a couple giant gobies for the invasive species museum, I might. I would call it The Wall of Shame! Your right salmon/and alewives have nothing to do with them, that’s the problem. The zebras, gobies and spiny fleas plus the rest are making chumps out of the MDNR fishery Division biologists, and the salmon experiment. Your also right we need more predators that will eat them, walleyes, Perch etc… because as you said “salmon/alewives have nothing to do with them” and that’s the problem!

  10. Anonymous/Tom (one in the same), not sure what you saw, but almost certainly not a goby. Most never surpass 4-5 inches, with a few rare ones over 6-7. Possibly sheepshead or gizzard shad? Gobies are another exotic invader. Bass, walleyes, brown trout and many other species feed on them. Salmon/alewives have nothing to do with them. They’re just too prolific, spawning multiple times, and are very successful at it. Well adapted too to forage in the dark.

  11. I don’t have a block, protecting the alewives is the root cause of all our problems, that simple. Scoop last year year on the Grand Haven pier I saw 2 gobies as long as my shoe (I had heard stories about bigger) I wear size 14’s. Add the shear numbers of gobies this is a testament to the mismanagement of Lake Michigan (The resource) and the failure of the salmon experiment. Tournaments or not the plan isn’t working.

  12. I wouldn’t call it a block,protecting alewives is the problem. regardless of what you or anyone else says, all the problems with the lake can be traced to the salmon /alewife experiment. I see the MDNR propaganda machine is out. ” Not sure if more walleyes from stocking or spawn in Bay De Noc” “Alewives dying on the beach a good thing” and my fav “We are fortunate to have a remarkable group of people”blah blah (fish stocking). But Dexter also said the fishery pumps between $1.6 billion to $4.2 billion into the economy. This leaves a margin of error of plus or minus $2.6 billion? Can’t figure out where $2.6 billion went? Check Saginaw Bay. Green bay again, so then lets make walleyes only one over 23 inches like Bay De Noc which feeds Green Bay, and drop the Perch limit to 15, and close during spawn, working out so well there should work state wide including lake Michigan. Scoop last year on the Grand Haven pier I saw 2 gobies (in a pile) that were as long as my shoe, I wear size 14. I had heard stories of bigger down there. Add the shear numbers of gobies this is a testament to the mismanagement of Lake michigan, and the failure of the salmon experiment.

  13. You’ve got a block Tom. You can’t see that there are more walleyes in Green Bay (which is part of Lake Michigan) than you could ever imagine, so many in fact that they don’t even need stocking, they do it on their own. Absolute world-class walleye fishing at Sturgeon Bay, for example, which is directly connected to the lake by the shipping canal. How many times do you need to hear the walleyes prefer the shallower, more fertile and warmer bay waters?

    Please don’t drag out that old survey where you believe only a few folks worked to protect alewives, or I might have to drag out your old perch survey that had even far fewer people signing the petition. Both are meaningless in the grand scheme of public opinion. A salmon tournament on the Kewaunee/Door Peninsula just ended Sunday with an announced 2,667 entrants. Small potatoes? Tell that to the five ports that reaped the economic benefit of all those visiting anglers from across the country.

  14. The official plan only allows 200,000 to 400,000 pounds of walleyes for all of Lake Michigan and connecting waters. Billions of pounds of alewives. 2 to 4 million pounds of Perch. Look it up. We catch mostly invasive white Perch in Muskegon Lake, I kill every one of them. Trophy gobies off the Grand Haven pier. They stopped stocking salmon and browns in Huron too many predators eating them (walleyes) same would happen here, and the real reason we can’t stock Perch. The DNR’s own survey less than 580 people voted to save alewives. The other DNR survey only 12 to 14% fish lake Michigan (salmon) and now they’re going to force people to buy a salmon stamp (all species). If a lake is full of fish, and and you don’t want to fish is one thing. If you don’t fish a lake because there’s no fish to catch is quite another. There’s plenty of food in Lake Michigan for walleyes they’re called alewives and salmon, after they get done cleaning them out, they’ll go to work on the gobies, and the other invasives chinook wont eat. The Muskegon river system is the number one walleye spawning site for lake Michigan. Hasn’t had a good spawn in going on 60 years now, ever since alewives showed up. Sorry by law native fish should be No.1 Priority, instead it’s alewives. We’re wasting $billions of dollars “fighting invasive species” but protecting alewives. Asian Carp are a freshwater fish they do not need to adapt to our freshwater system, as long as alewives are protected so are asian carp and every other invasive species we now have, which are increasing and they don’t grow too big for predators like asian carp. Alewives or asian carp? Really not that hard of a choice, if your decision is science based. Salmon have no value unless they wipe out the alewives, then thier job would be done, and the lakes would be better for. A healthy lake is what we’re all supposed to be working for, No. 1 priority.

  15. Don’t know where you get your facts. I’ve cut up thousands of salmon in my lifetime and have never seen anything but alewives and an occasional smelt inside. I’ve caught them for 40 years, even fished perch some of the same days we’d fish salmon. There were a lot of both back then, in the plankton/phytoplankton-rich waters so murky you couldn’t see bottom off the piers unless it was dead calm for days.

    Not sure why you can’t see that walleyes are EVERYWHERE in Green Bay, from Green Bay, Wisc., to Sturgeon Bay to Sister Bay to Marinette and Menominee to the Bays de Noc. Eight-pound-plus average in the Cabela’s tourney over the weekend at Sturgeon Bay. Records broken in an Anglers Insight Marketing walleye tourney at Oconto earlier in the month. World-class fishing in a bay that is also attracting throngs of bass, perch, brown trout, muskie, pike and salmon anglers, right now. Those walleyes don’t have to stay in Green Bay waters. They can easily swim into Lake Michigan if they want to. The deep, cold waters of Lake Michigan, where there’s far less to eat and the water is so clear. I wonder why so few go there? Hundreds of charter boats, none of them catching walleyes on the lake, yet even a neophyte with 10 minutes of instruction can go on the bay and catch walleyes!

    Don’t need much bait for salmon? Tell that to the 2,000-plus in Door and Kewaunee counties right now fishing. Ask the bait and tackle shops there how much “stuff” these guys buy, even if they already have a boatload. The same shops also sell nightcrawlers, leafworms, wax worms, shiners and fatheads to guys fishing perch, bass, walleyes, pike and inland lake panfish.

    How many of those goby-catching kids are still out there fishing? I’d expect every one of them, since they had so much fun. But wait — maybe mom and dad has to work, and can’t take them. Maybe it’s too far to bike, or they don’t have money for bait. Hmm …

    Of course there’s “time” to go fishing. Each of us has to make it. The FACT is that one study after another shows time and money as the two biggest factors working against recruitment and retention of anglers and hunters. Pure research, Tom. Not an anti-salmon angler’s angry rants.

  16. Scoop listen to yourself. People don’t have time to go fishing. but they have time for salmon? Walleyes don’t like Lake Michigan, but non-native fish do? Most people can’t afford the gas to go salmon fishing, let alone the boat etc… but that’s what most people do? Don’t look at those salmon tournaments look at the other salmon tournaments?Please. My friend didn’t catch his first legal walleye in Michigan until he was 38 years old, (I took him to saginaw bay) that’s just wrong. Regardless the plan to keep alewives dominant is wrong, it means sacrificing the entire native/natural ecosystem no matter what you say. Hundreds of thousands of alewives dying on the bneach is not a good thing. Any kid I take fishing wants to know when they can go again, smart phone, video games or not.Facts You can’t stock salmon with a healthy native fish population, they’ll eat them. They’ll also eat alewives. The DNR is on record if alewives try to come back in Saginaw bay they’ll plant more walleyes (don’t have to plant now) imagine that if there’s a threat of an invasive species they’ll plant predators who’d a thunk it! Bait shops closed because you don’t need much bait for salmon. You chose one fish chinook over the entire ecosystem and the common good costing billions of public dollars, that’s also a fact.

  17. Not those tournaments the udder tournaments? Please. Perch guys on Muskegon Lake hundreds PER DAY, one guy started renting out shantys/guide people from all over were coming, warm weather couple hundred boats out front perch boats. Gone when Perch gone. Same early 80’s we had 90 boats in a thursday walleye tournament, walleye gone,perch gone that gone bait shops closed, license sales drop, invasive species increase rapidly. How hundreds if not thousands of people fishing Perch from the piers PER DAY has no economic value to you people is beyond me. Why do they have to force people to buy the salmon/trout (all species ) license? Every kid that fished our goby tournament, bugged thier parents to go goby fishing everday, because they could catch them! Lots of them! Right in with video games and sponge bob they wanted to go fishin! If you want to compete with video games fishing has to be more fun. In order to be more fun they have to actually catch fish, but having lots of perch to catch threatens the alewives and salmon, so not allowed. Forcing people to fish salmon isn’t working economically, or environmentally, the environment is supposed to come first. Walleyes don’t like Lake Michigan? 10,000 years OK, but now no? Scoop, I can’t tell if your off your meds, or taking to many?

  18. Rob, just curious, where are you looking for sport fishermen? Surely not along Lake Michigan ports, which unless it’s a “blow day” are bustling with activity.

    “As soon as the BabyBoomers are gone, this thing is history, unless the DNR can plant some fish into iPods.”

    Now there you go, Tom M. Someone who sees what the real problem is with recruitment and retention.

  19. The lake has been “quietly managed” for salmon since 1966, when the first cohos were put in. By the early 1970s, the world-class fishery was discovered by the rest of the country thanks to articles in Outdoor Life, Sports Afield, Field & Stream.

    Walleye in Green BAY = walleye in Saginaw BAY = walleyes in the BAYs de Noc. The main LAKE will never be good for walleyes. They prefer the warmer bay waters. Cabela’s is in Sturgeon bay this weekend for one of its national walleye tournaments.

    You’re looking at small scale salmon tournaments. Look to the big boys, Salmon-A-Rama and the Kewaunee/Door County Salmon Tournament, a combined paid registration of more than 4,000 anglers in the past week alone. There have been many more between 400-1,000 angler events at various ports this summer, with more to come. You’re looking at tournament “trail” TEAM events, which are very different (typically with 4-6 anglers per boat). How many anglers came back to fish the perch in Muskegon Lake? 100? 200? 500? You try to mock the salmon fishery but honestly, I don’t think you understand it.

  20. Everything coincides with the drop/loss of the Perch and walleye. 1986 is when the lake was “quietly” managed for salmon/alewife perch and walleye gone. Walleye restored saginaw bay people are crawling all over each other to get at them, not on the west side. 2008 after slight increase from 2005 perch spawn Muskegon lake full of perch fisherman, 50 a day knocked them back down as did alewife increase from salmon stocking cuts. Salmon fishing? Lets see.Salmon Tournaments. 2013 Muskegon tri port challenge 59 boats.2012 salmon unlimited open northport Il. 61 boats. 2012 coho classic kenosha wi. 51 boats. 2012 port washington shootout 29 boats 2012 brew city salmon tournament milwaukee 34 boats. 2012 salmon unlimited racine 50 boats. Yep thousands of people want dem salmon. The muskegon tri port spread over 3 ports because the price of gas “don’t have to spend the kids college fund” thier words. Nobody else wants to spend the college funds or $4 bucks a gallon for gas to catch a salmon either scoopy. If we had good fishing as in catching there’d be people, I assure you, saginaw bay there is people because they are catching walleyes. Regardless we’re supposed to be doing what’s right for the lakes, the ecosystem/natural resource can’t do that and protect alewives at the same time. People want to know they have a good chance at catching fish, wherever, they don’t catch fish somewhere they go somewhere else. They don’t catch many fish or mostly garbage they quit all together and don’t buy a license. Can’t afford salmon fishing same same. People have time, they don’t want to waste time, or money. Salmon are an incredible waste of money, because they require the destruction of the entire resource to exist. 50 boats in a salmon tournament dosen’t justify that, never will.

  21. Tom, what’s your definitive proof that fishing license sales dropped due to perch and walleye? There is none. You’re pulling that out of a hat. Look around you. There are perch and walleye aplenty inland and in a number of Great Lakes bays. When I was a kid the small inland lakes were packed. Today, you can sometimes have those same small lakes to yourself, or with one or two others.

    One study after another shows TIME (or lack of it) and MONEY (or lack of it) as the main focus areas of declining participation in both fishing and hunting. The breakdown of the family unit is also playing a role.

    But, the same declines have been seen in bowling, recreational softball and volleyball leagues, pool and English dart leagues, you name it! Some folks are actually spending more time with their families. Sadly, many others have bought into the “more is better” lies when it comes to electronic gadgets, and there are more Smart Phone, tablet, computer and video game users than ever before. TV — don’t get me started. The initials should stand for time vacuum. But times have changed. You either adapt and fish for what’s biting at that time of day or year, or sit and complain about it on the computer. I’m going fishin’!

  22. Alewives are an invasive species. Fishing license sales (1/2 million) dropped after 1986 as perch and walleye dropped. Results of protecting alewives (alewives dominant plan)

  23. There are many examples. There is no logical reason for anyone to want alewives. We have to sacrifice the entire natural ecosystem to protect the alewife/chinook show. Any increase in most of our native fish is a threat to the alewife/chinook. The DNR’s are converting the entire system to invasive friendly, Which has resulted in the mess we have now. They want to dedicate all the spawning/nursery areas to salmon and trout. Each chinook has to have 123 pounds of alewives per chinook to hit 17 pounds. This rule controls thier actions, whether stocked or wild spawned each chinook only lives 3 years and has to have 123 pounds minimum or the salmon guys ain’t happy! Hypocrites? Liars and thieves is more accurate. The mismanagement of the lakes costs every person in the US and Canada billions and billions of dollars a year. The salmon have no value, they’re poison with fins. How much this or that person makes from chinook fishing is errelevant. The fact that we have to intentionally destroy the natural ecosystem to keep chinook is what’s relevant!

  24. Should mention that Native Atlantic Salmon are being stocked into Lake Ontario as well; the native Atlantic Salmon population is preyed on by introduced Pacific Salmon. To further the issue is like any other in today’s society. Money vs. Mother Nature

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  26. This all should come as no real surprise, after having played Frankenstein with the Lakes since the mid 60’s, with absolutely no one to answer to and continuing to this day to totally wreck havoc on the Lake system and its heritage, under the guise that people will continue to be enticed and “lured” into Sport Fishing…Sport fishing for all practical purposes is over and will never come close again to the Monster that Michigan DNR created.
    The $4-8 billion figure that’s thrown around is BS. I have not seen a Sport fisherman in months, let alone see one catch a fish!
    As soon as the BabyBoomers are gone, this thing is history, unless the DNR can plant some fish into iPods.

  27. Pingback: Clicked-on countdown continues | Great Lakes Echo

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