09/05/2026
Harvesting overabundant small pike remains one of the wisest and most delicious decisions a walleye angler can make.
One of the first studies to uncover the links between populations of pike, perch, walleyes, and other species, biologists Dennis Anderson and Dennis Schupp discovered in 1986 that increasing abundance of pike led to declines in abundances of perch and walleye, as well as largemouth bass, black crappie, and sunfish in a North Central Minnesota lake.
Years later, suspicious of the effects of high-density populations of small pike, Lilienthal examined a large data set from North Central Minnesota lakes, a region that encompasses about 60 percent of the state’s counties. “It’s this zone that contains 93 percent of state’s problematic pike lakes that are also stocked with walleyes,” he says.
“My review of the most recent (2013) data revealed that 372 of the 722 (52 percent) North Central lakes stocked with walleyes had high density populations of northern pike, with more than 7 fish per gill-net lift,” he says. “When I looked at walleye gill-net catches I found that high-density pike lakes averaged walleye catches that were consistently 50 percent lower than in the lakes with lower-density pike populations. Not surprisingly, perch populations were in terrible shape in these same lakes.”
As biologist Tim Brastrup told me years ago, “Pike populations were never meant to mirror those of sunfish or other animals lower on the food web.” Putting the rarity and value of large pike into perspective, MNDNR research scientist Andy Carlson says: “In the heart of the walleye and pike belt in Central Minnesota, a 10- to 20-pound pike has become so rare that removing a single fish from a midsize lake can have a devastating impact on the fishery.” It’s a double-edged sword. Removing the genetics of a large spawning female prompts remaining smaller pike to mature and spawn at earlier ages, producing slow-growing pike at exponential rates. Also, large pike are excellent fishery “fixers,” keeping numbers of small pike in check via cannibalism. Large pike are effective predators on small pike predators.
Unwanted consequences result from unbalanced populations, be it pike, deer, or pine beetles. We shouldn’t be surprised when removing generations of large pike and reverting to high densities of small pike not only destroys the population balance of pike, but also reduces abundances of prey species such as yellow perch—a critical species for recruiting and sustaining walleye populations.
Cory Schmidt, In-Fisherman