Commentary: The Center for Biological Diversity today sued the U.S. Fish and Wildlife Service over its denial of Endangered Species Act protection to the Rio Grande cutthroat trout, a cold-water fish of the headwaters of the Rio Grande, Pecos and Canadian rivers in Colorado and New Mexico. In response to a 1998 Center petition and two lawsuits, the agency determined in 2008 that the rare trout warranted protection due to habitat loss, introduction of nonnative trout, climate change and other factors. But in 2014 the Service reversed course and denied protection to the species.
“The Rio Grande cutthroat trout survives only in a few isolated headwaters,” said Michael Robinson of the Center. “Without help from the Endangered Species Act, this fish will disappear forever.”
Characterized by deep crimson slashes on its throat, the fish once swam throughout the Rio Grande, Pecos and Canadian river basins from Colorado to southern New Mexico. It is now limited to a small number of tiny headwater streams in only 11 percent of its historic range.
Today’s lawsuit not only seeks endangered status for the Rio Grande cutthroat trout, but also challenges a new Fish and Wildlife Service policy of disregarding historic range and instead assessing species’ viability only within their current range, regardless of how diminished that might be from historic levels.
Under the Endangered Species Act, a species qualifies for protection when it is “in danger of extinction in all or a significant of portion of its range,” to make sure species are protected before they’re at risk of disappearing from everywhere they once lived.
The challenged policy, however, precludes protecting a species as endangered based on the fact it no longer occurs in much of its range — a rule that prevents species like the trout from receiving needed protections and ignores the certainty that, without intervention, dangerous trends will continue and likely worsen.
“Congress wisely specified that imperiled wildlife should be afforded legal and practical protection before they’re reduced to the point of looming extinction,” said Robinson. “What a travesty that we now have to file a lawsuit to get the government to protect the Rio Grande cutthroat trout when it’s already gone from almost all its historic range.”
Background
Most surviving Rio Grande cutthroat trout populations are too small and too isolated from each other to survive the effects of loss of genetic diversity; other populations are hybridized with non-native rainbow trout in ways that can eliminate the traits that make the Rio Grande cutthroat unique. Unchecked logging, road-building, livestock grazing, pollution and global warming are also pushing these cutthroat toward extinction.
Today’s lawsuit points to the inconsistency of the 2014 Fish and Wildlife Service decision not to place the Rio Grande cutthroat trout on the endangered list with the agency’s previous 2008 finding that the trout needed federal protection. Since 2008 conditions for the fish have only worsened, with persistent drought contributing to forest fires that burn trees needed to shade trout streams. Silt deposited in rivers by post-fire erosion is another threat since it can kill trout and smother their eggs.
The Service’s 2014 denial of protection identified hybrid fish, with as much as 10 percent ancestry from non-native trout, as somehow bolstering the Rio Grande cutthroat’s long-term survival. But in 2002 the agency had taken the biologically prudent course of only considering fish with less than 1 percent hybridization to contribute to conservation of this native animal.
In denying protection to the trout two years ago, the Service could identify only 55 populations that could be considered marginally secure based on absence of exotic trout, number of fish, and the length of streams that they inhabited. But these populations still face threats from fires, drought and outright habitat destruction.
Read more about the Center’s work to save Rio Grande cutthroat trout.
The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.1 million members and online activists dedicated to the protection of endangered species and wild places.