AUGUSTA — A state legislator from Portland wants to expand the state’s decade-old ban on lead fishing tackle to help prevent the poisoning of loons and other wildlife.

Proposed by Democratic Sen. Anne Haskell, L.D. 730 would prohibit sales and use of lead sinkers and jigs weighing as much as 1 ounce or as long as 2½ inches.

The current law prohibits sales of lead sinkers weighing as much as a half-ounce.

Loons and other water birds often mistake the small, toxic weights for the pebbles they typically swallow to aid in food digestion.

Haskell, who serves on the Legislature’s Inland Fisheries and Wildlife Committee, said Maine’s loon population is a “fragile treasure” that must be protected. “This change will reduce mortality and improve the chances of survival for Maine’s loons, both today and into the future,” Haskell said in a news release. “This is a problem we can actually do something about.”

The fisheries and wildlife committee will hold a public hearing on the bill at 1 p.m. Thursday. Haskell said there are many cost-competitive alternatives to lead sinkers and jigs that are made from materials such as tin, steel and tungsten-nickel alloy.

Under the expanded law, violations would remain civil violations carrying fines of $100 to $500.

Lead poisoning from sinkers and jigs is the leading cause of death for adult loons in Maine, according to Maine Audubon, one of the bill’s supporters.

Nearly one-third of the dead loons that have been collected in Maine since 1987 died because they swallowed lead sinkers and lead-headed jigs, said Susan Gallo, a wildlife biologist for Maine Audubon.

Maine is one of the few states that ban lead tackle, along with New York, New Hampshire and Vermont.

Sinkers are attached to fishing lines to weight hooks for casting and trolling. Jigs are fashioned as part of hooks and lures for the same purpose.

Lead tackle threatens not only water birds, but also eagles and other wildlife that eat fish that have swallowed lead sinkers or jigs, according to the Vermont Fish & Wildlife Department.

David Trahan, executive director of the Sportsman’s Alliance of Maine, said his organization has concerns about the bill but will testify neither for nor against it.

Trahan said a stricter law should be phased in so fishermen can be educated about the sinkers and jigs that must be removed from their tackle boxes and how to dispose of unwanted items properly. “We’d like to see a smooth transition from lead to other materials,” Trahan said. “Otherwise, you’re going to have some people out there fishing illegally and not even knowing it.”