Baitfish Dynamics

By Steve Heiting, Managing Editor

Over the years I’ve heard many musky anglers tell the story of a big follower or a missed fish that left a “washtub-sized boil” on the surface when it vacated the area. In more than 30 years of chasing muskies I’ve seldom seen a boil that was truly as big as a washtub, but here I am writing about one I saw last August.

I’m not sure what caused me to look back over my shoulder at my fishing partner, Kevin Schmidt, but I’ll never forget the sight. Kevin was in themiddle of a figure- 8 and about 10 feet behind the boat was a boil that indicated the fish that made it meant business. An instant later Kevin’s rod loaded as the musky clamped down on his Mepps H210, and as he struggled against the bucking rod he pulled the fish’s giant head out fromunder the boat ” I remember thinking the big spinner looked small in the musky’s bucket of a mouth. Immediately I tossed my rod aside, pulled the trolling motor from the water and grabbed the net.

Kevin Schmidt prepares to release the giant discussed in the opening of this article.

The musky preferred to stay under the boat and for a moment looked like it was going to tangle the line in the outboard’s propeller. But Kevin leaned on the long rod to steer the fish away from the big motor, and as he walked the fish up the starboard side of the boat it hesitated as if to ponder its next move. “Take him now,” Kevin said, and I slipped the big net under the fish and the fight was over.

Kevin’s musky, the longest either of us had ever caught fromthis particular water, was taken from a prominent main lake point that has everything a big predator could want”wind that hits it from multiple directions, deep water nearby and a variety of complex food shelves. Until last year, we would fish the spot early in the week after arriving at the lake because it always looked so promising, but since we never had much action we’d eventually drive right by and never give it a second thought.

That all changed in 2010. Muskies, and big ones at that, were lined up in every nook and cranny of the point. Every boulder, weed stalk and shelf seemingly had multiple muskies holding on it. In two weeks we boated 10 fish from the point and realized that maybe we’d been too critical of it previously. In 2011, we saw more of the same. Meanwhile, less than a half-mile away are located other islands, points and reefs that have always been consistent producers for us, yet in the last two seasons muskies have been frustratingly absent.

So, what gives?

There are lots of variables that can affect a musky “bite,” but the answer to why muskies are using a spot is, and always will be, baitfish. Besides spawning and eating, fish have no other known biological need. Since spawning occurs during a short window in spring, that leaves hunger as their only motivation for most of the year. If food is present, muskies will not be far away.

 Baitfish Dynamics

Ecosystems are constantly in a state of flux. We see this on land when populations of deer or rabbits increase or decrease, and even then we often can’t explain it, as in the case of ruffed grouse. The same occurs underwater even though we can’t actually see it. While we would like to think our favorite lake or spots should produce muskies every time we visit, this just isn’t the case.

Baitfish populations constantly rise and fall, and when the population of one species decreases another usually increases to fill the void. Even if the population of a fish species seemingly too small to appeal to muskies were to crash, muskies may be affected because a prey species they would prefer to eat is now out of a food source and may need to switch to another. That’s life when you’re on top of the food chain.

To understand what happens within baitfish populations, I talked with Musky Hunter’s Research Editors, Steve Pallo and JordanWeeks. Pallo is retired after serving as head of the Illinois DNR’s fisheries department, and Weeks is a Wisconsin DNR biologist stationed in LaCrosse, Wisconsin. Both are members of the American Fisheries Society’s Esocid Technical Committee.

“Assuming habitat is good, successful spawns depend on several things,” said Weeks. “First, production is oftentimes based on adult populations; when adult densities are high, young fish survival is low because adult fish prey on the young fish and reduce their densities to carrying capacity, So, bumper year classes often occur when adult densities are low or moderately low.

“Second is water temperature. Steadilywarming water is ideal [for spring spawners]. This maximizes egg survival and hatching success and provides the young fish the best opportunity to survive.”

I had thought fishing pressure on spring spawners such as perch, walleyes or crappies would make a difference, and that white suckers would have less fluctuation because few anglers intentionally fish for them. Weeks discounted this: “All fish populations fluctuate from year to year and the sucker is no exception. Year class strength is dictated by available food resources, environment, and the number of adults.”

Southern musky waters are usually loaded with gizzard shad, which Pallo said “seem to know the population is low and compensate for that by overspawning to rebuild the population.

“The term in the fisheries world for this is ‘compensation.’ In some years, especially following a weak spawn or a heavymortality event such as a summerkill or winterkill, shad tend to have super spawns. In years with super spawns the young of the year tend to be smaller in fall than normal years. This small size can carry over until the next year; this makes the shad vulnerable to predators longer and the predators will show increased growth and survival also,” Pallo continued.

Not as much is known about what affects fall spawners like whitefish and ciscoes/ tullibees. Their incubation time can last through the winter (90 days for ciscoes and around 130 days for whitefish) and the young of the year remain in the spawning area until the water warms in spring when they leave for deeper water.

Said Weeks: “Recruitment is one of the most studied things in fisheries. In almost every instance scientists find that recruitment is highly variable from year to year and waterbody to waterbody. It is very hard to determine what causes good or bad year classes. There are hundreds of variables.”

Musky populations themselves will rise and fall, but since adult fish rarely have predators outside of man and muskies are long-lived, population variance usually isn’t dramatic.

Spawning movement is one explanation of why some spots are better seasonally than others. In southern reservoirs, shad may spend the entire year suspended over deep water, but in the spring when water temperatures are between 50 and 70 you had better check shallow water because that’s where the shad will go to spawn and the muskies will be with them. Falling water temperatures in autumn send whitefish and ciscoes en masse to spawn in shallow rocky/gravelly/sandy areas, and many of the biggest muskies will be right behind them.

Fish that muskies eat are also constantly on the search for food, which can explain why spots turn on while others turn off.This can occur weekly, seasonally or annually. An explosion in the population of a preferred prey species, like gizzard shad, may result in such an abundance of food thatmuskies don’t have to work hard to eat and are thus less likely to be fooled by fishermen’s efforts. Conversely, if prey species are lacking, muskies theoretically should be easier to catch. If the population of a particular prey species is reduced, muskiesmay shift their attention to something else.

Musky fishermen can only see the rise and fall of baitfish populations through the result of their efforts. Spots on lakes hold multiple fish one year and are vacant the next. A lake is “hot” or a year or two, and then suddenly you can hardly get a follow there while another water just down the road produces better.

 So, Now What?

How does a musky fisherman ” who may have only a couple hours each week to figure out the current pattern, or who wants to get the most from a week’s vacation on prime water ” figure out where he should be fishing?

An outstanding Wisconsin musky guide once toldme that finding muskies is easy. “Make sure your boat is over weeds in eight feet of water and have one guy cast toward shore and the other cast away from shore, and you’ll catch them,” he said.

That oversimplification is generally true.Weeds hold baitfish, and muskies use weeds as cover and eat baitfish, so the equation adds up. But before that guide positioned his boat over eight feet of water he will have taken you to a lake that’s been producing for him, and likely will have the boat on a weedbed that held muskies during previous visits.

Guides have to figure out where to fish every year. They may have hundreds of waters within the area they work and they probably know a dozen or so intimately. Usually they’ll know their way around many more. At the start of a season, if a guide starts running up a losing streak on a favorite water he’ll avoid it and concentrate on waters that are producing. Struggling for two or three days in good fishing conditions may be all a guide needs to stop fishing a lake until things change.

On the other hand, as long as a lake is active a guide will take advantage of the situation.Thus, hiring a guide for a day or two when you first arrive in an area is always a smart investment because he’s not going to want to hide his “magic” ” he will take you to lakes that are producing. If hiring a guide is not for you, fish a couple different waters early in the week and then go back to the ones that produced.

Weekend warriors can do the same thing. Check out the fishing on a couple of your favorite lakes when the season starts and if you’ve had good action on certain waters and not on others, concentrate on the lakes that are producing. Networking with friends can further dial you in more quickly.

Larger, “destination” waters are a whole other ballgame because trailering your boat elsewhere is usually not an option. And, really, you don’t need to, because larger waters can better absorb a “pulse” of baitfish. You just have to figure out where the muskies are.

Usually you won’t see muskies on your electronics unless they’re suspended over deep water. What I’ve found to be an accurate indicator of whether a spot may be productive is baitfish on my graph’s screen as I approach the spot. In very deep water it may be clouds of baitfish just off the breaks or in the open water between structures. In shallower water, say 25 feet or less, you won’t often see schools of smaller baitfish, but if you see “hooks” near bottomas you approach the structure chances are very good that spot will produce for you.

I don’t care what kind of fish my graph is showing as hooks, just that they’re present. They’re most likely walleyes, smallmouth bass, suckers or perch. Their presence indicates the food chain is in action, so muskies should be nearby.

When I first arrive at a destination water I constantly watch my electronics as I approach spots, looking for baitfish. Early in my trip I will fish every spot I know as well as “new” spots I hadn’t previously checked out. You have to honor those on which you have history even if baitfish aren’t evident on your electronics. However, after two or three days I’ll completely skip unproductive spots ” regardless of past history ” to focus my efforts where muskies are currently located. In most cases the productive spots are showing baitfish on my electronics.

Fifteen years ago when I started fishing Minnesota’s Lake Vermilion, we could tell whether the mid-lake reefs would be worth fishing by seeing baitfish on the graph as we approached. I’ve applied that to a number of waters throughout the muskies’ range and it seems to hold true everywhere.

I haven’t mentioned wind anywhere in this article, even though I’m a big believer in using it and/or current tomy advantage whenever possible. However, if baitfish aren’t holding on or near a wind-buffeted spot, chances are very good the muskies aren’t there, either.

Ecosystems are constantly changing and the life of a musky revolves around procuring food with the least expenditure of energy. Translated, that means they’re going to be where they find the most baitfish. Be conscious of trends in the location and abundance of baitfish in your favorite waters and you’ll be much more efficient in your musky fishing.

Steve Heiting is Managing Editor of Musky Hunter magazine. For more about Steve, visit

Gregg Thomas

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