Environmentalists seeking federal protections for the Arctic grayling are challenging the U.S. Fish and Wildlife Service’s 2020 decision not to list the Big Hole River-dwelling fish as a threatened species under the Endangered Species Act.
Monday’s legal filing by the Center for Biological Diversity, Western Watersheds Project and Butte resident Pay Munday is the most recent chapter in a decades-long saga over the management of Arctic grayling, which were once widespread throughout the upper Missouri River basin and are now found almost exclusively in southwest Montana’s Big Hole and Ruby rivers.
In the lawsuit filed Jan. 30,, the plaintiffs argue that the federal government has failed to incorporate climate change impacts in its analysis of grayling viability and taken an overly optimistic view of a landowner-driven effort to minimize threats to grayling.
“Voluntary measures haven’t recovered the grayling, and are not enough to bring this unique fish back from the brink of extinction,” Western Watersheds Project Executive Directory Erik Molvar said in an email about the lawsuit. “The compounding threats of irrigation withdrawals, livestock degradation of key spawning streams, and climate change warrant bold federal action to protect the grayling’s last remaining strongholds.”
In addition to providing habitat for fluctuating numbers of grayling, the Big Hole and Ruby are cornerstones of local agricultural and recreational economies.
Environmentalists argue that the Big Hole River Candidate Conservation Agreement with Assurances, a stakeholder-spawned effort to stave off federal protections for grayling, lacks the kinds of enforceable standards and regulatory teeth required by the Endangered Species Act.
The CCAA was formed in 2006 and includes representatives from the federal and state government, as well as non-governmental organizations and more than 30 landowners.
Environmentalists say USFWS has been overly optimistic in its assessment of the CCAA’s ability to engender sufficient habitat protections for grayling and “cherry-picked” population data from 2013-2016 — a period of relative stability — to suggest that voluntary efforts had eliminated the need for federal protections.
The federal government’s analysis of stream temperature trends and graylings’ ability to adapt to warmer water also play a central role in the lawsuit. Plaintiffs say that USFWS has leaned on unresearched claims that grayling find refuge from warm water in cooler tributaries of the mainstem Big Hole. They say even if that assumption is correct, there’s no guarantee that future conditions will continue to provide reprieve from the warm temperatures that stress and sometimes kill grayling.
The groups are asking the court to toss out the government’s 2020 finding that protections are unwarranted and send USFWS back to the drawing board to further study threats to grayling survival.
The 2017 Montana Climate Assessment found that warming temperatures are expected to reduce snowpack and shift run-off to earlier in the year, resulting in warmer, lower-volume streamflows as the summer progresses. Those findings have implications for both agricultural producers and biologists seeking to support healthy aquatic ecosystems.