The saga of the Sunapee Trout (a.k.a. Arctic Char)

If you wanted to see the Sunapee trout, you might be inclined to search in its namesake, New Hampshire’s Lake Sunapee. But this elusive fish has long been extirpated from the Granite State, and from neighboring Vermont, where it once lived in the Northeast Kingdom’s Averill Lakes. Sunapee trout remains in 14 bodies of water in Maine, which harbors the last endemic populations in the lower 48 states.

Sunapee trout is often called Arctic char, although it is technically a subspecies of Arctic char (Salvelinus alpinus oquassa) . It is also known by a variety of other names, including blueback trout, silver char, golden trout, white trout, red trout, American saibling, and Oquassa trout.

Young adult Arctic char are slim, around 6 inches long, and weigh a few ounces, but they can survive for up to 15 years, grow to 20 inches, and reach 3 pounds. Mature char have a dark back, pale belly, and spotted sides. Fins are orange or red, with white front margins. Both sexes develop intense mating season coloration, with backs ranging from brown to blue with orange spots, and bellies pink to dayglo orange.

Arctic char live farther north and are found in deeper waters and at higher elevations than any other freshwater fish.

“Prior to the 1800s, and going back to deglaciation, we can infer that the species was widespread across the region,” said Frank Frost, a biologist with Maine’s Department of Inland Fisheries and Wildlife. When the glaciers retreated, Artic char became secluded in northeastern lakes, he said, and “as new species colonized post-glaciation, char would have succumbed to various pressures.”

The species prefers waters colder than 55 F. but will travel throughout the depths of a lake (except for the warm surface waters of summer) in pursuit of small fish, insects, zooplankton, and other prey. From July through September, Arctic char inhabit cooler, deeper, more oxygenated waters. At the southern edge of its range in Maine, these fish are a bellwether for how other coldwater fish may fare in a warming climate.

According to Jared Lamy, fish habitat biologist for New Hampshire Fish and Game, “Habitat loss and the introduction of non-native species, most notably lake trout, landlocked salmon, and rainbow smelt, are the cause of extirpation for (Arctic char) in New Hampshire. They simply cannot compete with most other fish species.” Overfishing, especially during the spawning season, also contributed to the species’ decline.

State biologists have attempted reintroducing the species in Third Connecticut Lake, Penacook Lake, Sawyer Pond, Tewksbury Pond, and Connor Pond. Alas, these efforts have been unsuccessful, and Arctic char have been absent from New Hampshire since the 1970s. Lamy said wildlife managers do not plan additional reintroduction efforts, in large part because, “[Arctic char] are incompatible with many species that are present in New Hampshire lakes.”

In Maine, as in New Hampshire, the introduction of lake trout has hindered the Arctic char. Even though lake trout is a close relative of Arctic char and is native to many waterways in the Northeast, in places where it was introduced as a sport fish the two species hybridized and, over time, lake trout genes dominated. As a result, Arctic char have been displaced wherever lake trout have been released into the same waters.

What does the future hold for Arctic char? Maine’s goals for protecting the species’ unique gene pool include limiting the number of fish that are caught each year and preserving suitable habitat. Preventing the introduction and impact of invasive fish species is critical, and Maine is addressing this through public education and by controlling smelt populations.

Frost is part of a team working to translocate Arctic char into another Maine body of water to conserve the population and improve species resiliency. “We are selecting waters …[with] excellent water quality and a fish assemblage that would allow char to thrive,” he said. “The main goal has always been to conserve the populations that we now have by having a ‘backup plan’ should a population be threatened.”

By any name, the saga of Arctic char is a cautionary tale about what happens to native populations when other species are introduced and when a species is heavily overfished.

Michael J. Caduto is a writer, ecologist, and storyteller who lives in Reading, Vermont. He is author of “Through a Naturalist’s Eyes: Exploring the Nature of New England.” Illustration by Adelaide Murphy Tyrol. The Outside Story is assigned and edited by Northern Woodlands magazine and sponsored by the Wellborn Ecology Fund of New Hampshire Charitable Foundation: nhcf.org.