Press Release
Two Southwestern Fish, Rio Grande Chub and Sucker, Not in Danger of Extinction
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ALBUQUERQUE, N.M. – After a thorough review of the best available scientific and commercial information, the U.S. Fish and Wildlife Service has determined that the Rio Grande chub and the Rio Grande sucker do not warrant listing under the Endangered Species Act. 

The Rio Grande chub and the Rio Grande sucker often co-occur within the Rio Grande Basin. These cool-water fishes are found in slow moving water at mid-to-high elevations. They are found in waterways with water levels that can fluctuate dramatically and are adapted to withstand these changes.

After completing status reviews for each species; and consulting with scientists, state agencies, species experts and others; the Service concluded that neither species is in danger of extinction or likely to become in danger of extinction and thus do not meet the definition of threatened or endangered species. The primary factors considered in the analysis as impacting the survival of these species include water diversions, groundwater withdrawals, dams, nonnative species, wildfire, and climate change climate change
Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.

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Monitoring and conservation efforts for these fishes have been occurring for several decades. These ongoing efforts include a 10-year Conservation Agreement for the Rio Grande chub and the Rio Grande sucker signed in 2018. This multi-partner agreement includes federal agencies, Tribes, states, municipalities, non-profits, and private organizations. Through this agreement, long-term management actions for the Rio Grande chub and the Rio Grande sucker includes monitoring populations and habitat, securing and enhancing populations, and improving watershed conditions into the future.

The Rio Grande chub is a small-bodied fish with a maximum length of eight inches. It is found in New Mexico, Texas, and Colorado. Across its range, there are currently 53 populations. The Rio Grande chub is an omnivore and eats fish, invertebrates, and vegetation. It prefers pools with cover such as woody debris, boulders, or vegetation.

The Rio Grande sucker is found in New Mexico, Arizona, Colorado, and Mexico. Across its range, there are currently 32 populations. As a benthic feeder, it is found at the bottom of riverbeds, eating algae off cobble and gravel. 

A notice of the not warranted findings for the petitions to list the Rio Grande chub and the Rio Grande sucker can be found in the Federal Register on June 20, 2024.

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