YELLOWSTONE NATIONAL PARK
Grayling Creek in northwest Yellowstone National Park will once again be home to a population of its namesake fish, the Arctic grayling.
National Park Service crews this spring hatched nearly 100,000 grayling eggs in the upper reaches of Grayling Creek. Native westslope cutthroat trout are also being reintroduced, with nearly 700 fish and more than 10,000 eggs stocked in 2015, as of July 1. These introductions for grayling and westslope cutthroat trout will occur for at least three years in Grayling Creek.
The introductions are part of a concerted effort to restore a native fish community to the large, remote Grayling Creek watershed. The Madison River and its tributaries, including Grayling Creek, once held the southernmost population of fluvial – or river dwelling – Arctic grayling, a fish known for its large dorsal fin and iridescent color.
“Support by our agency and non-governmental organization partners, as well as funding through donations to the Yellowstone Park Foundation, are the reasons this large restoration effort has been successful, ”said Todd Koel, leader of the park’s Native Fish Conservation Program.
Scientists in the 1890s described the fluvial Arctic grayling population as abundant, but by the 1950s the grayling, one of 11 fish native to Yellowstone, was virtually extirpated. At the time, only one original population of genetically-unaltered westslope cutthroat trout remained in the park.
Crews from the NPS, Montana Fish, Wildlife and Parks, the U.S. Fish and Wildlife Service, U.S. Forest Service and Turner Enterprises have worked in partnership for nearly a decade to create a large, secure refuge with 35 miles of stream habitat within the Grayling Creek watershed.
A natural waterfall was modified in 2012 to create a barrier that prevents nonnative brown and rainbow trout from invading the restoration area from downstream sources.
In 2013 and 2014, interagency crews treated the proposed restoration area with rotenone – an Environmental Protection Agency-approved pesticide that targets fish – to remove all nonnative and hybridized trout. These treatments so far have been successful, as no brown or rainbow trout have since been found in Grayling Creek.
The primary source of fluvial Arctic grayling eggs is Axolotl Lake, a small lake near Ennis, where hundreds of Big Hole River grayling are held as a source for eggs. Montana FWP’s Big Timber Hatchery oversees egg collection and rears them until they are ready to stock in the wild.
Westslope cutthroat trout eggs being reintroduced to Grayling Creek are held at a small egg-rearing facility at the Sun Ranch in the Madison River Valley. The eggs are collected from wild sources and brought to the ranch where they’re reared until they’re almost ready to hatch, and biologists then stock them in the wild.
A video of the Arctic grayling being released in Grayling Creek is available at youtube.com/watch?v=mHU7zlR4dto.