Jan 17, 2024 - News

Debate over listing blind catfish as endangered centers on water resources

A long image of a white, translucent blind catfish.

The widemouth blindcat is an eyeless catfish that lives in the Edwards Aquifer. Photo: Courtesy of Hendrickson Lab/ Ichthyology Collection at the University of Texas at Austin

More than 1,000 feet below San Antonio, small, blind catfish — some of the rarest in the world — live out their days in the dark caves of the Edwards Aquifer.

What's happening: The U.S. Fish and Wildlife Service has proposed listing the toothless blindcat and widemouth blindcat as endangered, saying they could go extinct because they cannot survive being sucked up by groundwater wells.

  • But local officials say the proposal is based on assumptions and hypotheticals and there's a significant lack of information about the species.

Why it matters: Opponents worry protecting the catfish could mean pumping less water from the aquifer at a time when the city's population is booming and droughts are expected to worsen with climate change.

Catch up fast: Federal officials proposed the endangered listing and began accepting public comment in August. In December, they reopened the public comment period, following a request from the San Antonio Water System.

  • The extended comment period closed last week.

What they're saying: "While the great depth of their habitat protects them from many human-caused threats, thousands of these fishes were likely lost over the last one hundred or more years as groundwater pumping activity increased across Bexar County," U.S. Fish and Wildlife Service biologist Michael Warriner said in a statement.

The other side: "The potential impacts of the Proposal are enormous and may severely impact the provision of water to SAWS customers, requiring an entire revamping of several areas of SAWS service area costing billions of dollars," Edward Guzman of SAWS wrote in a public comment.

  • "An endangered designation may require disruptions to pumping in highly populated areas in San Antonio and Bexar County, negatively impacting the reliability of the water and electrical service in those areas," state Sen. José Menéndez (D-San Antonio) wrote.
  • Republican U.S. Rep. Chip Roy agrees.

Context: The Edwards Aquifer is the source of more than half of San Antonio's drinking water, though SAWS has diversified its sources.

Of note: The widemouth blindcat has not been seen in any well since 1984, per Fish and Wildlife. Small numbers of the toothless blindcat have been found in one well as recently as 2022.

Zoom in: The toothless blindcat has no eyes and a suckerlike, whiskered mouth to scavenge food. It lives in total darkness in the groundwater.

  • The widemouth blindcat is also eyeless but is a predator instead of a scavenger.
  • They are two of just three known blind catfish species in the U.S., all of which are found in Texas. The translucent fish rely on taste, smell, heat, flow and touch to find food.

By the numbers: An estimated 535,194 toothless blindcats and 269,280 widemouth blindcats have been lost throughout the operation of 51 wells, Fish and Wildlife estimates.

  • Both species of blindcats likely numbered in the tens of thousands historically, but their exact numbers are unknown.
  • The greatest loss of blindcats likely occurred between the early 1940s and 1960s, when the largest number of groundwater wells were drilled, per a federal report.

Zoom out: The Edwards Aquifer supports seven other species listed as endangered: the fountain darter, Texas blind salamander, San Marcos salamander, Texas wild-rice, Comal Springs riffle beetle, Comal Springs dryopid beetle and Peck's Cave amphipod.

  • These species live in the Comal and San Marcos springs system, which gets its flow from the Edwards Aquifer.

What's next: Federal officials could issue a decision by August, within one year of the initial proposal, Fish and Wildlife spokesperson Aubry Buzek tells Axios.

  • The agency could find the species to be threatened instead of endangered.
  • Federal officials also could extend the proposal by six months if a significant disagreement exists within the scientific community.

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