Skip to main content

Media contact: Emilie Blevins, Senior Conservation Biologist, Xerces Society for Invertebrate Conservation
[email protected] |971-266-3467


PORTLAND, Ore. – Last month, world leaders met in Glasgow for a global climate conference and to announce their public commitments to reversing climate change. Yet some plant and animal populations have already declined to critical levels requiring swift action, according to a report released today by the Endangered Species Coalition and partners. Last Chance: 10 U.S. Species Already Imperiled by Climate Change highlights the plight of ten dwindling animal and plant species that are being impacted—directly or indirectly—by global climate change.

The report includes the western ridged mussel (Gonidea angulata), which plays an outsized role in its freshwater habitats, filtering and purifying water that benefits all species in their ecosystems. Each mussel can live for decades in rivers and streams. 

The Xerces Society for Invertebrate Conservation nominated western ridged mussels for the report because, “This species has declined the most of any western North American mussel species, and is the only member of its genus so it’s really unique,” said Emilie Blevins, a conservation biologist and freshwater mussel lead with the Xerces Society. “Drought from climate change is having a disproportionate impact on them. Every year we see dying mussels during surveys, and we’re just really concerned.”

Once abundant in rivers and streams in a number of western states, western ridged mussels are no longer found in more than 40 percent of their historic range. Recent unexplained mass die-offs have significantly decreased populations. Their survival is further jeopardized by human-driven activities including dams, pollution, development, grazing and – not least – climate change.

“Mussels are the unsung heroes of our rivers. They support everything else.” said Blevins. “When we see fish stranded in pools in streams during a drought, they are actually more likely to survive if mussels are present, because they’re filtering the water and providing a better food base.”

Freshwater mussels, as a group, are among the most imperiled species groups in the world. In August of 2020, the Xerces Society filed a petition to list the western ridged mussel as an endangered species under the U.S. Endangered Species Act. If listed, the western ridged mussel would join more than 90 other mussel species in the United States (of the 300 or so species that live, or once lived here) that are already listed under the ESA, with the hope that it will not also join the 30 or so North American species that are now extinct.

With a tenth of the nation’s mussel species already lost forever, the stakes are high. In an effort to help conserve the species, Xerces biologists are working to survey for previously unknown or unrecorded populations, monitor existing populations, and collaborate with biologists and land managers to protect mussel beds from other impacts.

The western ridged mussel is just one of the species highlighted in the report, which includes species with similarly shrinking populations and sensitive habitats impacted by the effects of climate change.

10 Species Already Imperiled by Climate Change:

  • Florida Key deer
  • Ka palupalu o Kanaloa
  • Maui parrotbill
  • Mexican long-nosed bat
  • Western ridged mussel
  • Whitebark pine
  • Diamondback terrapin
  • Elkhorn coral
  • Monarch butterfly
  • Sierra Nevada yellow-legged frog

The Endangered Species Coalition produces a Top 10 report annually, focusing on a different theme each year. The full report, along with photos can be viewed and downloaded here:




About the Xerces Society

The Xerces Society for Invertebrate Conservation protects the natural world by conserving invertebrates and their habitat. Established in 1971, the Society is a trusted source for science-based information and advice and plays a leading role in protecting pollinators and many other invertebrates. Our team draws together experts from the fields of habitat restoration, entomology, plant ecology, education, pesticides, farming and conservation biology with a single passion: Protecting the life that sustains us. To learn more, visit or follow us @xercessociety on TwitterFacebook or Instagram.