Editorial on native fish conservation and chemical use,
Michael Enk for the Montana Chapter of the American Fisheries Society
Saving Montana’s Cutthroat Trout
We’ve all seen the bumper
sticker: Native Montanan. It expresses pride in our heritage, the pride that
native Montanans take in long-term family attachments to this wonderful state
and its open spaces.
But there are other native Montanans to consider,
ones that are part of everybody’s heritage. They are our native fish and
wildlife, those species that occupied this place long before our forebears
settled here, or for that matter, before any humans occupied this state. Among
them are some remarkable fish, including the westslope cutthroat trout, a fish
familiar to most Montanans. Once common throughout the western third of Montana,
westslope cutthroats are now imperiled. A close cousin, the Yellowstone
cutthroat trout, is also imperiled in the south-central Montana streams where it
once flourished. The long-term existence of these natives depends on a public
that is open-minded about the measures that it will take to ensure these fish
endure.
I am an officer with the
Montana Chapter of the American Fisheries Society, a professional organization
whose membership includes most fisheries scientists in Montana. Our profession
has learned much about westslope cutthroats. We’ve learned that when Lewis and
Clark navigated the upper Missouri country, this fish occupied nearly 10,000
miles of the streams and rivers east of the Continental Divide.
They now exist in about 600 miles of streams, mostly in reaches less than
five miles long. These remnant populations are at high risk of extinction. West
of the Divide in Montana, the situation is less dire, but westslope cutthroats
still face many of the same threats that severely reduced their numbers in the
Missouri drainage. With luck, you can still catch a 16-inch cutthroat on some
western Montana rivers. But today
that would be an extraordinary catch in the Missouri River drainage, where the
journals of Lewis and Clark provided the first scientific description of the
westslope cutthroat trout. Meriwether Lewis reported that Silas Goodrich caught
six of these fish ranging from 16 to 23 inches at the Great Falls of the
Missouri River. Goodrich wouldn’t find them there today.
Land uses have harmed cutthroat habitat, but the non-native rainbow, brown and brook trout we have introduced have also squeezed out the natives. We introduced the non-natives for sporting purposes, but the cutthroats have paid a toll. What can we do to restore some cutthroat populations? Often, the only effective solution is to remove competitors, the progeny of the sportfish we stocked years ago. This raises red flags with some anglers, but it shouldn’t. We can restore cutthroats by removing non-native trout in selected streams, generally small streams that don’t support much angling. Removing competitors in enough miles of stream to allow the cutthroats to reestablish migratory connections to rivers would be a worthy goal. That means in the Missouri drainage, in addition to having popular rainbow and brown trout fisheries, we could also have waters where our kids, like Goodrich, could catch large westslope cutthroat trout.
Fisheries scientists didn’t come into their profession with the goal of killing fish. But we’ve found that the occasional and selective removal of non-native fish in some streams is necessary to restore natives. Unfortunately, angling, netting and electrofishing cannot usually remove all non-native fish. We’ve tried, but most projects using these measures fail. The most effective alternative is the judicious use of fish toxicants, or piscicides. Fisheries scientists are concerned about water quality. We stand up for clean water all the time. But our support of piscicide use demonstrates two things. First, the situation is so grim for native fish that we have to occasionally use chemicals. And second, years of experience have shown us that these chemicals can be safe and short lived.
For example, a
piscicide was used to successfully remove illegally introduced brook trout in 27
miles of Arnica Creek, a native cutthroat stream feeding Yellowstone Lake.
Chemicals were also used to preserve native bull trout in Sun Creek near
Oregon’s Crater Lake National Park. Fishery professionals have been using
piscicides to conserve native fish throughout the West – including Montana –
for years. Used properly, these
chemicals affect only gill breathing animals. The careful use of piscicides is a
necessary tool to ensure native trout persist and endangered species listings
are avoided. As advocates of native
species preservation, clean water and angling, fishery professionals take
seriously our pledge to use chemicals sparingly, carefully and only as a tool of
last resort. We just hope someday an excited Montana youngster can brag about
the large native cutthroats she caught in an upper Missouri River stream.
Michael Enk of Great Falls is a fisheries biologist and elected officer of the Montana Chapter of the American Fisheries Society (PO Box 1408, Great Falls, MT 59403; 791-7729).
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