Conservation of Fluvial Arctic Grayling: a Candidate Conservation Agreement in the Big Hole River, Montana

Arctic grayling Thymallus arcticus in Montana were historically distributed in lakes and streams in the upper Missouri River drainage.  Fluvial Arctic grayling populations have been reduced to one population in the Big Hole River, approximately 4% of their native range in Montana.  In 2010 the U.S. Fish and Wildlife Service (USFWS) classified Arctic grayling in the Missouri River drainage as a candidate species (i.e., warranted but precluded) for protection under the U.S. Endangered Species Act (ESA).  Currently, Arctic grayling conservation efforts include implementing one of the largest conservation programs on private lands in the country; The Big Hole Arctic Grayling Candidate Conservation Agreement with Assurances Program (CCAA).  The CCAA is an agreement between Montana Fish, Wildlife and Parks, the USFWS, and any private landowner who voluntarily agrees to manage their property to mitigate threats to Arctic grayling.  The landowners receive assurances against additional regulatory requirements and incidental take authority should Arctic grayling be listed as threatened or endangered under the ESA.  Enrollment includes 31 private landowners and over 156,000 acres of private and state land.  Conservation goals are achieved by working with each landowner to develop a site-specific conservation plan (SSP) for their land that identifies conservation measures that provide benefits to Arctic grayling.  Conservation measures 1) improve streamflow, 2) improve and protect stream and riparian habitat function, 3) reduce or eliminate fish entrainment, and 4) remove barriers to Arctic grayling migration.  Since 2006 over 100 habitat restoration projects and several landowner SSPs have been completed that address limiting factors for Arctic grayling in the Big Hole River.  These projects largely focus on reducing the impacts of grazing and irrigation practices through the use of riparian fencing and updating irrigation hardware.  Additionally, the SSPs help both landowners and biologists manage, monitor, and evaluate the conservation measures taken on the enrolled lands.