WHITE BEAR LAKE  — Minnesota’s campaign to reduce lead in fishing tackle has stagnated in recent years, but the issue will be resurrected next month at the annual meeting of the Minnesota Chapter of the Wildlife Society.

More than 200 wildlife biologists from across the state are expected to attend the gathering in Bemidji. Topics are expected to include lead fishing tackle and lead firearms ammunition.

National tackle manufacturers have increased production of steel and tin split-shot sinkers to accommodate anglers in the small but growing number of states with bans on lead. There’s still uncertainty, however, over how bad the lead problem is.

The state Department of Natural Resources conducted a study in 2006 to try to figure how much lead was in popular fishing lakes. DNR fisheries biologist Paul Radomski concluded that in a 21-year period, anglers dumped more than 9 tons into Lake Mille Lacs and more than 2 tons each into Rainy Lake and Lake of the Woods.

It’s not clear what the effect of that lead is. For example, researchers agree that a single loon that eats a single split-shot sinker will die from lead poisoning. But it’s not clear how many loons are actually being killed by anglers’ lead and whether the deaths constitute a threat to the overall population.

Some entrepreneurs say the specifics of lead poisoning aren’t as important as just eliminating it altogether.

“There’s no reason for lead in our tackle,” said Brad Yaritz, who sells lead-free tackle. “It’s not in our gasoline, it’s not in our paint, it’s not in our toys. What are we doing throwing it in the water?”