About this time every year, Minnesota's fish population gets a sizable boost from the Minnesota Department of Natural Resources. Millions of tiny walleye, trout and bass are trucked from tank to lake each spring.
Stocking has been common in Minnesota for nearly a century but Neil Vanderbosch, a fisheries program consultant for the DNR, said most people don't know much about it. We asked him for a crash course.
How much does the DNR stock?
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"A lot" was Vanderbosch's short answer. In all, 350 million small fish are poured into lakes every year. The vast majority of those are walleye fry, two- or three-day-old fish roughly the size of mosquito larvae. The rest are trout, crappie, bluegill and bass. Even with those large numbers, 30 years of DNR survey data suggest 85 percent of walleyes caught are naturally reproduced.
How many lakes are stocked?
Of Minnesota's 10,000 (officially 11,842) lakes, more than 2,000 are stocked every year or every few years. Trucks arrive with fry in the spring or sometimes with six inch fingerlings in the fall. With some rare exceptions, large lakes like Mille Lacs and Lake of the Woods have self-sustaining populations. Stocked lakes tend to be small.
Where do all the small fry used in the DNR's stocking program come from?
Stocked fish have the same humble origins as regular fish. The DNR operates eight "egg takes" in northern sections of the state. As spawning fish swim upstream, a few are trapped in places like the Pike River in Tower, Minn., and their eggs are literally squeezed out of their bodies in to pans of water. Those eggs are hatched in any of 16 hatcheries scattered around the state and shipped to lakes by the tanker-load.
How much does it all cost?
Every year the state spends roughly $8 million on the whole stocking program. Half of that is spent on walleye alone, with the rest split between other fish and administrative overhead. In case you'd like to understand the math, that works out to roughly $8 every time an angler eats a stocked walleye.
What's the point?
The DNR often stocks lakes to repair ecosystems after winter kill or over fishing, but Vanderbosch said the bulk of his job involves creating walleye fisheries where they don't naturally exist. Thanks to stocking, most Minnesotans live less than half an hour from a good walleye lake. In all, there are 1,400 walleye-rich lakes in the state, only 270 of which are naturally self-sustaining. The DNR stocks the rest so people can enjoy hauling walleye into their boats.
"People want to catch walleye," Vanderbosch said. "It's not the state fish for nothing."