The recent discovery of zebra mussels in a Becker County lake has forced the state Department of Natural Resources to make some changes in its muskie stocking program.

In a couple of weeks, 5-inch-long muskie will be put in Buck's Mill Pond near Detroit Lakes. By October they'll double in size and be moved to lakes.

But the pond is now considered infested with zebra mussels from an adjacent lake. That limits where the fish can be stocked, said Nathan Olson, an area fisheries supervisor for the DNR.

"We'll have to be looking at only taking these fish to other lakes that have zebra mussels," he said. "You know, with the zebra mussel issue, our number of lakes are sort of limited. Right now it could be as small as a list of just four lakes that could possibly get these fish."

• Map: See where zebra mussels have spread in Minnesota

Olson said the rearing pond can't be easily replaced. It has a dam so it can be drained and refilled each year.

Buck's Mill Pond accounts for less than 10 percent of the muskie stocked in Minnesota.

Regional Fisheries Supervisor Henry Drewes said the zebra mussel infestation will complicate stocking plans.

"So it will entail some just reordering of where fish go, perhaps at a cost of some efficiency," Drewes said. "Where typically those fish might be stocked more local we might have to move those a little further away so we can comply with the invasive species concerns."

That might mean trucking fish from rearing ponds in other parts of the state.

Drewes said the DNR stocks about 25,000 muskie in as many as 30 lakes each year.

By comparison, he said, the DNR stocks about three million walleye in more than 300 lakes a year.

The DNR uses about 280 rearing ponds, most to raise walleye, and a handful to raise muskie for stocking in Minnesota lakes.