High up against the Idaho border, the Centennial Valley remains wild and relatively untouched. It’s home to the Red Rock Lakes National Wildlife Refuge and a variety of wildlife, including a rare, native population of one member of the trout family: Arctic grayling.
The colorful fish with a long dorsal fin was a candidate for protection under the Endangered Species Act until 2014, when the U.S. Fish and Wildlife Service decided against a listing. Yet biologists still believe the species faces threats, and they’ve just proposed a program meant to conserve habitat while staving off any future listing of the species.
The U.S. Fish and Wildlife Service this week released a draft of a candidate conservation agreement that would create a program for landowners to take certain conservation measures in exchange for assurances that federal protection of the species wouldn’t affect their operations.
The program would ask landowners to leave some water in streams or keep cows away from riparian areas. In exchange, it would protect participating landowners in the event of a listing by allowing a certain level of incidental take, which includes accidental kills and any inadvertent harm or harassment of the fish.
“It’s basically just proactive conservation on the front end,” said Jim Boyd, a USFWS biologist.
Arctic grayling were once so numerous in the upper Missouri River drainage that Lewis and Clark noted them in their journals. In 1805, the explorers wrote of a “new kind of white or silvery trout” that populated the west, originally from Great Falls upstream.
That all changed as more people moved west. Habitat was dewatered and non-native fishes — rainbow, brown and brook trout — pushed them out. Stocking helped grayling persist in many lakes, but aboriginal populations became increasingly rare, now considered to exist in only a handful of places, including the upper Big Hole River and the Centennial Valley.
Red Rock Lakes National Wildlife Refuge is a population center for the Centennial grayling. Many of the fish spend part of the year in upper Red Rock Lake and move into Red Rock Creek to spawn. In the last couple years, after some habitat improvements, grayling have been seen moving up Elk Springs Creek, another spawning tributary that hadn’t supported fish for years.
The plan released this week aims to preserve habitat on private land, which Boyd said will build resiliency around the population’s core.
“It’s basically just trying to spread our eggs around and not just have everything centered on the refuge,” he said. “Never a great idea to have all your eggs in one basket.”
It focuses on four areas: improving streamflows, riparian habitat, eliminating migration barriers and keeping fish from getting sucked through irrigation infrastructure. A variety of remedies are offered to deal with those problems, and the plan says that not every measure will apply to all landowners.
The plan was released as Montana Fish, Wildlife and Parks considers public comment on regulation changes on the refuge. In 2013, FWP set a limit of 20 cutthroat trout at the refuge to see if the increased take would help the grayling population by freeing up more habitat. USFWS also had staff actively kill cutthroat.
After five years, they’ve decided to change course. Instead of seeing an improvement in grayling numbers, biologists saw a decline. Matt Jaeger, an FWP biologist, said numbers dwindled from more than 2,500 spawning fish in 2012 to fewer than 200 in 2016.
That pointed to another theory about what was limiting the population’s growth — the shallow lake. Jaeger said it doesn’t hold much oxygen and is no more than a meter deep in most spots, meaning it could easily freeze in the winter and erase any winter homes for the fish.
“By far the biggest population driver appears to be winter habitat in upper Red Rock Lake,” Jaeger said.
USFWS requested the agency propose a catch-and-release season for cutthroat and to change the season structure on a few other waterbodies there. FWP is working on a final proposal to offer to the Montana Fish and Wildlife Commission next month.
Comments will be approved before showing up.