Montana’s Arctic grayling are special fish. For starters, scientists believe that Arctic grayling migrated to North America much like our human ancestors: over the Beringia land bridge from Asia, possibly as far back as 3 million years ago. Sometime after that epic migration, Montana’s Arctic grayling were cut off from their ancestors to the north, likely by colossal ice sheets that once spread across much of the continent.
Here, in isolation from their relatives, Montana’s grayling population slowly changed over millennia to adapt to this new, warmer environment in the Missouri River Basin.
Lewis and Clark made note of these “new kind of white or silvery trout” in 1805. Early records claim that homesteaders once scooped buckets full of grayling from spawning tributaries, so it seems difficult to believe that after tens of thousands of years of abundance, these fish were nearly wiped out in a single human generation.
But that’s exactly what happened.
For decades, homesteaders gradually dewatered much of Montana’s Arctic grayling habitat above the Great Falls of the Missouri River, primarily for irrigation and livestock. Non-native brook, brown, and rainbow trout were introduced into the upper Missouri around the same time and thrived in the altered habitat. Another devastating blow came in the form of multiple droughts, which resulted in the total dewatering of vast segments of rivers and streams within the basin.
This perfect storm of threats nearly pushed the population over the edge.
Early fishery managers in the 1890s witnessed these events and decided to take action. They took grayling eggs from multiple sources in Montana and used them to supplement declining grayling populations in streams, rivers, and lakes across the rest of the state.
Over the next 90 years, at least 100 million grayling were stocked throughout Montana. Many grayling populations were introduced into high mountain lakes where there was a consistent supply of clear, cold water and few non-native fishes. These introductions were successful, but populations occupying lower elevation streams and rivers continued to decline as habitat destruction took its toll.
After more than a century of decline, however, good news came for the species.
For twenty years, with an Endangered Species Act (ESA) listing imminent, landowners and state and federal fisheries personnel in Montana’s Big Hole and Centennial Valleys came together, through voluntary Candidate Conservation Agreements with Assurances (CCAA), to achieve an amazing turnaround for Montana’s grayling.
Between 2006 and 2014, these stakeholders completed 250 voluntary conservation projects under the CCAAs to conserve grayling and their habitat. These projects included riparian fencing, irrigation flow reductions, improved irrigation infrastructure, fish ladders, improved stock water systems, and both passive and active stream restoration.
And the work paid off! Habitat quality improved significantly, and grayling populations have more than doubled since the CCAAs’ inception less than a decade ago.
The results were so impressive that in August of 2014, the Service announced that the Upper Missouri River Distinct Population Segment of Arctic grayling did not warrant protection under the ESA. “This is a prime example of what a CCAA can do, not only for wildlife, but also for sustaining the way of life in rural ranching communities,” said Service Director Dan Ashe the day of the announcement. “The conservation progress for Arctic grayling would not have been possible without the amazing support we have received from willing landowners and other partners in the Big Hole River and Centennial valleys.”
Today, managers are receiving reports of grayling farther downstream on the Big Hole River than ever before. Upstream, fish ladders have provided the fish access to another 67 miles of the Big Hole River and its tributaries. Anglers are catching more and more of the fish, although regulations require them to be released.
But before they do, they will no doubt pause to admire the fish’s dazzling coloring and that trademark dorsal fin. As the colors reflect in the sunlight and they release the fish back into the water, they will, perhaps unknowingly, be looking back in time. For nearly a hundred thousand years these grayling have called these waters home
If we have anything to say about it, they’ll be there for a long, long time.
By Ryan Moehring
Ryan Moehring is fish and wildlife Public Affairs Specialist in the Denver Regional Office.