RUMFORD – Fisheries biologists are reporting increasing numbers of angled trout and salmon with plastic lures in their stomachs, a state official said this week.

A report was released Monday by Fisheries Division Director John Boland of the Maine Department of Inland Fisheries and Wildlife.

“A discarded soft plastic lure consumed innocently by a brook trout from the bottom of a freshwater shoal, likely remains in that fish’s stomach for the rest of its life and may cause health issues such as ulcers and weight loss,” Boland wrote in the report.

Bass anglers commonly use soft plastic lures, often in water shared with trout and salmon.

To learn more about the problem, Inland Fisheries is cooperating in studies on the effects of such lure ingestion by trout and salmon.

One recent experiment was conducted at Unity College by Inland Fisheries pathologist Russ Danner, professor Jim Chacko, and state fisheries biologist Francis Brautigam. Another study is under way at Southern Maine Community College in South Portland.

Boland said the Unity College study discovered that 65 percent of brook trout voluntarily ate soft plastic lures if they were simply dropped into water.

“We found that fish retained the lures in their stomachs for 13 weeks without regurgitating them,” Danner said Monday. “They also began to act anorexic and lost weight within 90 days of eating a soft plastic lure.”

Anglers are being asked not to discard plastic lures into water and to try to retrieve any that have become unhooked.

Not regarding the chemical toxicity of ingested plastic, the fact that these lures are occupying space in a trout’s stomach limits its available space for food.

“Soft plastic lures come in every color, a myriad of sizes, and resemble every swimming, crawling, and flying creature a fish could imagine eating,” Danner said. “Large fish searching the waters of Maine are bound to come upon brightly colored soft plastic lures lost or discarded by anglers and consume these imitators of natural food items.”

That’s why Inland Fisheries is strongly urging anglers to switch from soft plastic lures to biodegradable ones.

Natural lure alternatives are available at many retailers and online, and should become the choice of people who love to fish Maine’s waters, Danner said.

There are estimates, Boland said, that as much as 20 million pounds of soft plastic lures are being lost in freshwater lakes and streams each year in the nation.

That doesn’t bode well for fish because the average life expectancy of such lures is more than 200 years.