The fish biologist sliced carefully just under the skin of the live brook trout, making a slit only large enough to tuck a nearly 2-inch-long radio transmitter into its body.
The fish was anesthetized, a tube pumping water into its mouth for oxygen, and lying in a wooden cradle on a thick, lake-soaked towel to keep its body moist. The theater was a dock under a gray morning sky on Mooselookmeguntic Lake, not an operating room full of lights and sterile surroundings.
Liz Latti, regional fish biologist for the Maine Department of Inland Fisheries and Wildlife in Region D, threaded the flexible antenna attached to the transmitter through a hollow needle and pulled it through the fish’s skin so it would be outside of its body.
This would make it easier to pick up its radio frequency from a plane or boat, but wouldn’t pull against the transmitter, she said on Monday. Latti also tagged the fish with a bright yellow wire-like tag — called a Floy tag — imprinted with a tracking number for anglers to report to the department.
It’s all part of a three-year study the Maine Department of Inland Fisheries and Wildlife is doing on Mooselookmeguntic Lake, which has a protected native brook trout fishery. This is the study’s second year.
Maine’s brook trout fisheries face some serious threats, including climate change that warms their waters and invasive species that eat their food. This first-of-its-kind state study will teach biologists what they need to know to help Maine’s heritage species of game fish survive.
Mooselookmeguntic is the state’s fifth largest lake behind Moosehead, Sebago, Chesuncook and Flagstaff. It is sixth largest if Spednic, which is partially in Canada, is counted. There is no ice fishing allowed and its fishery is native. It is one of hundreds of Maine State Heritage Fish waters, which means the state cannot stock it. That’s an increasingly rare treasure in Maine and one that several groups want to protect.
“Mooselook is the biggest wild fishery in the Androscoggin Basin. It’s the only one not stocked. Rangeley Lake, Kennebago and the others in the region are stocked,” said Latti, whose area of responsibility includes the Rangeley Lakes.
Latti sewed the brook trout’s incision with a surgeon’s suture needle, deftly knotting each dissolvable stitch. The wound would heal in a few days, she said.
Measurements were taken and the anesthetized fish was placed in a recovery cooler — basically a live well — to give it time to shake off the medication. The revived fish was released into the lake. And just like that, the brook trout joined the dozens of others that are part of the study.
Last year, the biologist team implanted 150 transmitters and applied 450 Floy tags. This year, the team of Latti, fellow fish biologists Tyler Grant and Dylan Whitaker and Unity College graduate and assistant Ashley Houle inserted 18 radio tags into 14 brook trout and four landlocked salmon and applied 94 Floy tags to smaller fish of both species.
“The reason there are self-sustaining salmonids (including landlocked salmon and brook trout) in Mooselook is because of the spawning areas in the tributaries,” Latti said.
She also credited the upper dam, owned and operated by Brookfield Renewable Energy Partners, that helps keep invasive species out of the lake. The dam separates Mooselookmeguntic from Rangeley Lake, which the state stocks.
The introduction of dams and logging operations degraded the trout’s habitats in the 1800s. The state’s brook trout management began in 1951, and now business and conservation are working together to strike a balance.
Brookfield’s Kyle Murphy was there Monday to help move fish from one part of the process to the next.
Brookfield has been working with the state for a number of years, he said. The company has dams on several other lakes in the state too.
Brookfield is one of several partners in the project, along with the Rangeley Region Guides’ and Sportsmen’s Association, Rivers Edge sport shop, Rangeley Lakes Heritage Trust and Maine Outdoor Heritage Fund.
The partners help in several ways, including money, equipment and hundreds of volunteer hours. A family who owns rental camps on the lake allowed the biologists to stay there for free, including dock space for their boats.
Several of the boats fishing for the project Monday belonged to Maine guides who were using their time, equipment and gas, plus not making a living that day, to catch the fish Latti and her team needed for the study.
The fish were carefully transferred from one net to another or from net to container, and direct human interaction was minimized by rubber gloves and other precautions.
The anglers caught several large fish. The biggest one was four pounds, three ounces. Several were in the 2-3 pound range. The fish have to be big enough to handle the radio tags or transmitters, Latti said. If the fish is too small, the weight added by the transmitter could affect its ability to swim.
The state record for brook trout is 12.5 pounds. The fish was caught in 1886 in Mooselookmeguntic Lake, according to MDIF&W records.
The quality of the fish caught this year for the study surpassed last year’s in terms of health and size, the biologists agreed. The study has one more year.
Biologists hope to learn enough about how the fish respond to temperature, water level, food and other changes as they occur, plus what their breeding habits are, to manage and preserve Maine’s heritage fishery statewide more effectively.
Data from the study could be used to decide on size and bag limits and identify whether the fish are becoming vulnerable to climate change or other stresses. It also can be used to guide restoration efforts in other parts of the state, Latti said.
The actual cost of the study has not been determined. Supplies are easy to tally, but figuring out volunteer hours and staff time will take some work, she said.
Once the study’s data is in hand, a community advisory group will be convened to figure out how to use it and to build a management plan.
Several members of the public stopped by on Monday, curious about what the biologists were doing. The scientists explained the process, answered questions and invited people to return.
“It’s part of why we’re here. We want people to see our passion, the process and to be involved,” Latti said.
