Mountain-Prairie Region
Endangered Species Program

ARCTIC GRAYLING
 

 
Fluvial Arctic grayling                                                           Big Hole River, Montana

Species Description:  Arctic grayling (Thymallus arcticus) is a freshwater fish in the same family (Salmonidae) as salmon, trout, and whitefish.  A distinctive morphological characteristic of this fish is its large, sail-like dorsal fin.  Arctic grayling is an obligate cool- or cold-water species.  Individual fish can range widely, moving tens of miles on a seasonal or annual basis between spawning, rearing, and sheltering habitats.

Location: Arctic grayling are native to drainages of the Arctic Ocean, Hudson Bay and northern Pacific Ocean in North America and Asia.  Two distinct populations historically inhabited waters in Michigan and Montana.  The Michigan population is now extinct.  Arctic grayling are still present in southwestern Montana.  The fluvial (river-dwelling) Arctic grayling population which was widespread in the Missouri River basin above Great Falls, Montana has declined significantly in range and abundance.  The remaining confirmed, viable population resides in the Big Hole River, upstream from Divide, Montana.

Legal Status:  Due to this decline the Service was petitioned in 1991 to list the fluvial Arctic grayling under the Endangered Species Act.  In 1994 the Service determined that listing the grayling of the upper Missouri River was "warranted but precluded."  From 1994 to 2004 the  fluvial Arctic grayling of the upper Missouri River remained a candidate species with a listing priority of 9, indicating threats were moderate-to-low in magnitude and imminent.  In May 2004, the listing priority was upgraded to 3, indicating threats were of high magnitude and imminent.  During 2003 to 2005, the Service was involved in litigation with the Center for Biological Diversity and the Western Watershed Project over the continuing "warranted but precluded" determination.  The Service settled a lawsuit over the legal status of the grayling on August 9, 2005, and agreed to make a final listing determination by April 16, 2007.

 
Upper Big Hole River                                  Steel Creek, tributary to Big Hole River

Ongoing Conservation Activities:  The Fluvial Arctic Grayling Workgroup was established in the 1980s to facilitate and coordinate grayling conservation efforts in Montana.  Since 1995, State and Federal agencies, including the Service, have participated in a Fluvial Arctic Grayling Restoration Plan to conserve the remaining fluvial grayling population in the Big Hole River and re-establish four additional populations.  The Service's Partners for Fish and Wildlife Program has been actively implementing restoration projects in the Big Hole River watershed for over a decade.  Montana Fish, Wildlife and Parks, Montana Department of Natural Resources and Conservation, USDA Natural Resources Conservation Service, Big Hole River Foundation, Big Hole Watershed Committee, and Trout Unlimited have participated in ongoing efforts to protect and enhance grayling habitat and the remaining population in the Big Hole River area.

Recent Actions : 

The U. S. Fish and Wildlife Service has withdrawn the fluvial Arctic grayling of the upper Missouri River from the list of candidate species being considered for protection under the Endangered Species Act. The Service has determined that listing this population of Arctic grayling at this time is not warranted because it does not constitute a distinct population segment.

 Conservation Agreement - Candidate Conservation Agreement with Assurances (CCAA) - Montana Fish, Wildlife and Parks has received an enhancement of survival permit under the Service's CCAA program to conserve and enhance the grayling in the upper Big Hole River.  The Natural Resources Conservation Service and Montana Department of Natural Resources are also signatories to the CCAA. 

For additional information about the fluvial Arctic grayling in the upper Missouri River see:
Service's ECOS webpage
Partners for Fish and Wildlife - summary of projects in the Big Hole River watershed
Montana Fish, Wildlife and Parks - grayling website
American Fisheries Society - Species of Special Concern report


Big Hole River Valley

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