On a beloved lake, a plan to save the trout by killing all fish
BANFF NATIONAL PARK, Alberta - It is perhaps the most-photographed Canadian vista, featured for years on the $20 bill as a symbol of the nation's beauty.
Moraine Lake, with its blue-green water surrounded by snowcapped mountains, attracts thousands of visitors daily to canoe along its tree- and rock-lined shores or admire its scenery.
Now the lake in Banff National Park, about 100 miles west of Calgary, has gained notoriety.
Park officials plan to kill all its fish as a first step to restoring the native bull-trout population, decimated by decades of stocking with brook trout and splake, a hybrid trout. Only by making Moraine fishless can it once again become a bull-trout habitat, said Charlie Pacas, the Parks Canada aquatic biologist at Banff.
It is one of the park's first aquatic restoration projects under a 1994 federal policy that encourages repopulating native species of wildlife and plants while removing exotic, or non-native, species.
Sharp criticism followed.
"If these species are self-sustaining, then what's the harm in leaving them there?" asks Craig Ritchie, editor of Real Fishing magazine. "You're removing trout and putting in trout. You end up with the same thing - trout in a lake."
Eradication complicated
His main concern is the project could be a first step toward halting fishing in Banff park lakes. Others object to proposed methods, such as poison, to rid Moraine of fish.
Hundreds of fish already have been removed from Moraine by angling and nets in the last two years, and Pacas hopes to begin the eradication program this fall. He said it would be at least four years until bull trout are reintroduced, and even longer before fishing can resume in the lake, which is about a mile long and several hundred yards wide.
Stocking Moraine Lake dates to 1915, with the introduction of cutthroat trout. Rainbow trout, also non-native, were stocked in the late 1930s and 1940s, with splake added in the 1960s.
The non-native species "out-competed" the bull trout, and food sources such as plankton-like invertebrates began disappearing, Pacas said. By the 1950s, good fishing existed only in those lakes that received fresh stocks annually, showing the inability of fish populations to regenerate, he said.
Stocking halted in Moraine Lake in 1971, but the bull-trout population was never able to recover, Pacas said.
Dave Hutton, who owns the Moraine Lake Lodge, supports the concept of reintroducing bull trout but wonders about the endless manipulation of wildlife.
"All the animals seem to have tags or collars," Hutton said. "I would like to see nature be nature."
That's the idea, said David Schindler, a University of Alberta researcher who said it was essential to establish benchmarks for research on species survival, global warming and airborne pollution.
"We'd like to have a few lakes left that are in their natural state so we have a long-term reference," he said. "We have so few we haven't screwed up."
Anglers have "a couple of million lakes" in Canada to choose from, he said, so "surely we can spare one or two to examine how to restore and preserve them."
Pacas noted that fishing in two of the targeted lakes - Moraine and Bighorn - never has been particularly bountiful or popular. Under the program, Moraine would reopen to fishing when the bull-trout population regenerates - at least five years away and probably longer - while Bighorn would be returned forever to its natural fishless state.
The first step - removing the estimated 1,000 fish in Moraine Lake - may be the hardest. Options include nets, fishing, electrofishing in which shocks are used to stun or kill fish, and poison. Explosives were ruled out after a public and media furor.
Trout vs. trout?
Natural options have also been considered.
"We have thought about using sterile bull trout to act as predators of non-native fish," Pacas said. "If you get a couple of those guys, they're good killers, you put 'em in there, they could have a good time chomping down on their little buddies."
Then comes restoring the bull-trout population, probably through restocking with adult and juvenile fish, along with fry and eggs. Pacas said only wild fish would be used, to avoid disease and other problems from hatcheries.
Jeff Perodeau, owner of Banff Fishing Unlimited and a member of an advisory committee for the project, said most people accept the concept but flinch at the methods.
Poisons that attack the gill system of fish also affect gill-breathing insects and other aquatic life, he said. To anglers, Perodeau said, the result is purely negative: "They see it as a bunch of dead fish."