For years, the Rio Grande chub and Rio Grande sucker swam throughout the Rio Grande River, which flows from southern Colorado through New Mexico and Texas.
That’s no longer the case. Both species have disappeared from at least 75% of their historical habitat, and the sucker is now considered rare in Colorado and has nearly vanished from the Rio Grande in New Mexico.
In response, WildEarth Guardians, a nonprofit environmental group, petitioned the U.S. Fish and Wildlife Service to list both imperiled fish as endangered species. The federal agency denied both federal protections in late June.
Joanna Zhang, wild rivers advocate with WildEarth Guardians, said both fish have experienced severe habitat degradation from agriculture, which sucks up 80% of the river’s water supply.
“When you're seeing that much water getting taken out, and then you have increased aridity and the drought that the West has been facing for a while now, you just ended up with habitat fragmentation,” Zhang said. “And fish, obviously, need water to survive.”
The Rio Grande chub and sucker are also threatened by human-caused climate change. Warming waters favor some nonnative species that outcompete them for food and territory, and rising temperatures force them to try to find cooler waters. What’s more, there’s the increasingly intense wildfires, which damage the river’s watershed and pollute its water quality.
“We’re at a hotter and drier climate,” Zhang said. “And you then pair that on top of a century of unsustainable use and dams and diversions, and it’s kind of a perfect storm [to harm the fish].”
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Nevada Public Radio, Boise State Public Radio in Idaho, KUNR in Nevada, KUNC in Colorado and KANW in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.
