NEW ORLEANS— The Center for Biological Diversity filed a formal notice today of its intent to sue to the U.S. Fish and Wildlife Service over the agency’s failure to designate critical habitat for the Pearl darter.

The Pearl darter once lived in both the Pearl and Pascagoula River basins in Mississippi and Louisiana, but now the minnow has been completely eradicated from the basin of its namesake river. Its reduced population is confined to only scattered locations in the Pascagoula basin, where it faces an increased threat of extinction from high levels of pollution and river-altering activities like instream gravel mining and dams.

“The Pearl darter not being found in the Pearl River anymore brings the story of the global extinction crisis home,” said Tierra Curry, a senior scientist with the Center for Biological Diversity. “Saving this special little fish means giving its home the highest level of protection, which will also improve water quality for the people who love the Pearl and Pascagoula rivers.”

The Pearl darter was one of only 25 species protected as threatened or endangered during the Trump administration — the worst record for protecting species of any administration since Congress passed the Endangered Species Act in 1973. But despite getting these protections, the fish’s habitat remains vulnerable to pollution and development because it has no designated critical habitat.

The Act prohibits federal agencies from authorizing activities that will destroy or harm a listed species’ critical habitat. Species with federally protected critical habitat are more than twice as likely to be recovering as those without it.

Hundreds of freshwater plants and animals in the Southeast are at risk of extinction, but the federal government has dragged its feet for decades, delaying the protections the region’s wildlife needs to survive and recover.

Earlier this year the Center filed suit in Washington, D.C., over more than 200 species awaiting decisions about their protection. In addition to the Pearl darter in today’s notice, the Center plans to initiate lawsuits for another 20 species waiting for listing and 88 species waiting for designation of critical habitat. It hopes to work out a schedule with the Biden administration to ensure plants and animals from across the country get the protection they need to avoid extinction.