MADISON — Competition among fish populations in the Kennebec River has caused slow, stunted growth of brown trout to the disappointment of local anglers, according to a biologist from the Department of Inland Fisheries and Wildlife.

Because of competition for food and habitat with salmon and other trout species, fisheries from Solon to Waterville are suffering from a lack in supply of healthy, large brown trout, said Jason Seiders, regional fisheries biologist for the Belgrade Lakes Region. The fish, which spend most of their lives in the ocean but return to freshwater to spawn, are one of the most desirable species for sport fisherman. For decades they drew large numbers of fishermen to the Shawmut Dam in Fairfield, but Seiders said that area is now just a shadow of the fishing area it once was.

Next week, the department will launch a two-year study of brown trout in the Kennebec River when hundreds of the fish that have been surgically implanted with microchips will be released from hatcheries into the river and tracked for information on habitat, seasonal movements, mortality rates and survival techniques, said Seiders, who spoke Thursday evening at Madison Memorial High School to a group of about 30 local anglers.

“Once we learn how these fish are behaving, we can learn how to better manage the river,” he said.

The Kennebec River, which originates at Moosehead Lake and travels 170 miles to the Atlantic Ocean near Bath, is split up by dams between Solon and Shawmut, the stretch the department is primarily concerned about.

Cold water in the Forks and Bingham have fostered growth of salmon and wild trout populations that extend into Solon, where warmer water harbors more brown trout, which in recent years have been stocked by the department, Seiders said. Both salmon and trout are living to old ages, but they are not growing large for a number of reasons, he said.

“These fish compete for the same habitat and the same food, and it’s caused this growth issue. We have lots of small fish, but we’re hoping to improve and get some big fish,” Seiders said.

He said the department also is considering changing its stocking programs and possibly changing fishing regulations for salmon in order to alleviate some competition for brown trout.

The department is sponsoring another meeting at 6 p.m. Monday at Lawrence Junior High School. The topic will be the decline of the brown trout population in the Shawmut area.

Rachel Ohm —  612-2368
rohm@centralmaine.com