Saving Michigan’s Coaster Brook Trout

I’m at a New Year’s Eve party, talking with a man, and I tell him I’m working on a story about the saving Michigan’s coaster brook trout. He tells me the fish has always fascinated him—so big and beautiful. Back when he was in college in Marquette, on the shore of Lake Superior in the 1970’s, he knew a local who understood where and how to catch coasters. “He could get as many as he wanted, could really slay ’em, then he’d bring them to the dorm and we’d cook ’em up,” the man says.

He pauses to recall the scene. “Every fish was this big,” he says, and holds out his hands, the space between them spread a foot and a half or more. As he’s telling me this, I too am picturing a pile of the giant speckled trout, their pink and green iridescent dots shimmering in the fluorescence of a dorm kitchenette, but I’m also thinking, I’ve never before met somebody who has eaten a measurable percentage of an endangered species population.

I concede I’m using the endangered species label loosely here, in a common-sense sort of way, or perhaps as nature herself might define it. Because, as incredible as it sounds, even though there are only an estimated 400 breeding adult coasters swimming in U.S. waters, the fish isn’t by law an endangered species yet. An effort is underway to list it, but the outcome is uncertain. In the meantime, the coaster is perhaps the most endangered, least protected fish in the United States. Yet startlingly few people seem to know or care.

Come trout season, you could go out and catch a couple of coasters and eat them—consume some percent of the remaining breeding population in one meal—and be entirely within the law, a situation pointed out to me by Casey Huckins, a fish researcher at Michigan Technological University. By comparison, Americans became alarmed in the early 1960’s when, in the lower 48, nesting bald eagle adults fell to about 800, and timber wolves numbered maybe 700 individuals, though thousands more of each animal lived in Alaska.

The coaster breeds nowhere in the United States beyond two locations in the Lake Superior watershed, specifically, in a small tributary near Big Bay called the Salmon Trout River, and about 120 miles northwest of there in streams and on shoals of Isle Royale. Those estimated 400 adults are all the breeders our nation has.

The Bush administration had refused to even consider listing coasters until the Sierra Club and the Huron Mountain Club sued to force the review of their petition, submitted in 2006. The recommendation is expected by April 15, 2009. If listed, the coaster would be the first Great Lakes fish to receive the designation.

What exactly is the coaster? Even in our genome-mapping age, this is not an easy question to answer, but the answer is central to the endangered species decision. Ever since Europeans first learned of coasters, people have figured the fish were simply large brook trout (or, as Canadians call them, speckled trout), fish that swam out to Lake Superior by chance or choice and grew much larger there because of the larger environment. Many fish species vary in size based on environment, and coasters present a dramatic illustration of that trait. For example, a nice brook trout might measure 14 inches and weigh a pound. But the world record coaster, caught near Thunder Bay, Ontario, back in 1915, measured 34.5 inches and weighed 14.5 pounds—1,400 percent heavier than a decent stream brook trout. Historically, adult coasters along the southern shore of Lake Superior tended to weigh less than north shore coasters, in the 2-to-5-pound range. Nobody denies the coaster is different from a typical brookie, but to receive the endangered species designation it must be shown to be a distinct population, which is a difficult status to prove. More on that later.