Rainbows Are Out And Cutthroat Are In

In Buffalo Creek, on the northern edge of Yellowstone National Park, rainbows are out and cutthroat are in.

In approving the Buffalo Creek Yellowstone Cutthroat Trout Conservation Project, officials of Montana Fish, Wildlife and Parks and the Custer Gallatin National Forest agreed to that.

The country’s first national park is still one of its most pristine ecosystems, however the introduction of nonnative trout species near the end of the 19th century, including rainbow, brown, lake and brook, is increasingly threatening native Yellowstone cutthroats.

When lake trout invaded the Yellowstone Lake system in the early 1990s this cutthroat population drastically declined from 4 million to only 400,000.

Lake trout are known as voracious predators and are now the largest fish species found in Yellowstone – they remain in the park’s lakes to spawn whereas cuttroats return to small stream spawning grounds.

The dwindling number of cutthroat are having a ripple effect on many other species throughout the park such as osprey, eagles, otters and black and brown bears who depend on them for food.

Thanks to advocates such as David Sweet- who was named one of Field & Stream’s 2013 Heroes of Conservation and many others a gillnet program has been implemented which removes 300,000 lake trout a year from Yellowstone Lake and since then the numbers for cutthroat have seen a noticeable recovery.

Although Buffalo Creek, which is part of the Lamar River watershed, has a different history.

It has never established a cutthroat population because of a barrier waterfall, despite its cold mountain waters being ideal for cutthroats.

As a result of cutt-bow hybridization, the creek’s introduced rainbows threaten the cutthroats below. (Rainbows readily spawn with cutthroats, compromising the native fish’s genetic integrity.)

The proposed Buffalo Creek project is essential to sustaining the Yellowstone cutthroat trout population in the Lamar River.

Mike Ruggles, Montana FWP’s regional supervisor in Billings, explained that as a headwaters tributary of Slough Creek and Lamar River, Buffalo Creek currently contains non-nativerainbow trout and is the main source of these fish entering the Lamar River.

The plan entails utilizing rotenone, a natural tree-based pesticide, to remove these rainbow trout over five years, followed by releasing native cutthroats.

As a result of climate change and the threat of nonnatives in the 352-mile system, the formerly trout-less creek will be claimed to increase cutthroat habitat.

Those who have previously submitted comments to the Forest Service in response to the plan have 45 days to submit written objections before final approval.

 

Sources: Fieldstream