Closure will help efforts to strengthen Arctic grayling population

The Montana Fish and Wildlife Commission on Thursday approved an emergency fishing closure for a portion of Red Rock Creek to protect one of the last aboriginal Arctic grayling populations in Montana.

The year-round angling closure extends from Upper Red Rock Lake to Elk Lake Road. Fishing upstream of Elk Lake Road using artificial lures remains open except for an existing seasonal closure from May 1 through June 14.

Because grayling numbers in Red Rock Creek have been low since 2016, their genetic variation has declined considerably. Montana Fish, Wildlife & Parks is working to strengthen grayling genetics here using Centennial Valley origin mountain lakes grayling to mitigate losses in genetic variation until the population recovers.

Low dissolved oxygen in Upper Red Rock Lake during winter has been identified as the primary limiting factor for grayling in the Centennial Valley. However, it is also important to minimize other sources of mortality while genetic infusion is occurring. Additional mortality could reduce the grayling’s ability to survive and reproduce, potentially eliminating hundreds of years of local adaptation that allow the population to persist.

The angling closure will protect grayling seeking refuge from harsh summer conditions in Upper Red Rock Lake and is a key part of a large-scale, collaborative effort between FWP, the U.S. Fish & Wildlife Service and other partners to increase the spawning population to ensure this remnant aboriginal grayling population remains on the landscape.

Additionally, the Fish & Wildlife Service is presently undertaking a species status assessment of the upper Missouri River Basin distinct population segment of Arctic grayling as part of recent litigation that claims it should be listed under the Endangered Species Act. The assessment and any subsequent listing decisions based on it will take angling restrictions and other mitigating conservation efforts into account.