BETHEL — The number of large trout caught in the Upper Androscoggin River near Bethel has been on the decline in recent years.
Inland Fisheries and Wildlife Department biologists are trying to figure out why.
IFW biologist Francis Brautigam met recently with about 30 fishing enthusiasts at the Bethel Inn to share observations and information, and discuss river management for the future.
Brautigam noted that the overall quality of the river water is vastly improved over what it was decades ago. He cited the closing of the paper mill in Berlin for improving the aesthetic appeal of the Androscoggin.
In the wake of improving water quality, IFW has regularly stocked the river with rainbow and brown trout for more than a decade. Biologists have also been tracking the size of both stocked and wild fish.
From 2001 to 2009, the percentage of all trout 14 inches and longer has declined.
Brautigam said there is some evidence that wild rainbow trout comprised a higher percentage of the larger, older rainbows caught by fishermen.
He said reduced sizes of fish are likely attributable to a combination of factors, including more competition due to higher stocking rates; marginal summertime water temperatures; possible poaching; barriers, such as poor quality road culverts carrying small tributaries, that limit fish mobility; and ironically, a decline in organic material that had been generated by the upstream paper mill, which fed the creatures that the fish in turn fed on.
And, he said, the more fishermen, the more fish are caught, released and handled. “It could make it tough for the fish,” he said. “I’m astounded at the use of the river.”
Brautigam also presented information showing that for the area 4.5 miles south of Davis Park in Bethel, summer water temperatures for two years were sometimes higher than recommended for trout.
Trout need colder water — which has a higher oxygen content — than most other species of fish. The preferred temperature range for rainbow and brown trout, said Brautigam, is between 54-66 degrees. The lethal level for brown trout is 80, and 77 for rainbows.
In 2008, he said, “river temperatures were outside of the preferred range, and on some occasions the daily maximums were close to lethal levels for rainbows. In 2003 over roughly the same time period, temperatures generally ranged outside the preferred range, and less than lethal limits, although sometimes water temperatures were in the preferred range.”
Several fishermen at the meeting said they, too, have noticed a decrease in the size of fish they have caught in recent years.
John Wight, who lives along the river south of Bethel, said he has noted summer water temperatures around 80 degrees, and refuses to take people fishing in those conditions for fear of further stressing the trout.
Another fisherman noted the recent Route 2 widening project in the Gilead area, where significant portions of the tree canopy that had previously shaded stretches of the river was removed. The result, he said, could be additional warming of the river water as it passes through that area.
Brautigam was also asked if it would be realistic to eliminate some of the competition for wild trout by ceasing to stock the river, or at least greatly reduce it.
He said the overall catch rates among fishermen would likely “plummet” in that scenario.
Brautigam said his department is in the early stages of developing a fish management plan for the river, and input from a wide range of anglers, fishing guides and fishing-related organizations is important. He plans to form a citizen advisory group this winter to help build a vision for the Upper Androscoggin, and work on a management plan.