ST. PETERSBURG, Fla.— Conservation groups launched a lawsuit against the Trump administration today for failing to protect Nassau grouper habitat, which faces threats from nearshore pollution and climate change impacts like sea-level rise and ocean acidification.

“These big fish need our help keeping their homes livable,” said Jaclyn Lopez, Florida director at the Center for Biological Diversity. “Clean and clear nearshore waters are important to Floridians, and they just so happen to be essential for the grouper, too.”

The Endangered Species Act prohibits federal agencies from authorizing activities that will destroy or harm a listed species’ critical habitat. Animals with federally protected critical habitat are more than twice as likely to be recovering as species without it. Today’s notice letter, from the Center, WildEarth Guardians and Miami Waterkeeper, warns officials they may be sued for failing to act.

The Nassau grouper used to be one of the most common groupers in the United States. Overfishing contributed to a 60% decline. In 2016 the National Oceanic Atmospheric Administration listed the grouper as threatened under the Endangered Species Act in response to a scientific petition from WildEarth Guardians.

“Critical habitat designation is a key part of the strong protections of the Endangered Species Act,” said Taylor Jones, an endangered species advocate at WildEarth Guardians. “The agency has a responsibility to fully implement the law in order to protect this amazing fish.”

Nassau grouper is native to South Florida and the Caribbean, including the U.S. Virgin Islands and Puerto Rico. Poor water quality and increased sedimentation due to land-development practices threaten coral and macroalgae that are important resources during the grouper’s various life stages. Coral reefs are also acutely threatened by climate change impacts, including sea-level rise and ocean acidification.

“Nassau groupers, like thousands of other species, are dependent upon a healthy coral reef ecosystem to survive,” said Rachel Silverstein, executive director of Miami Waterkeeper. “With coral reef habitat rapidly disappearing, it is imperative that the agency designate Nassau groupers’ critical habitat, as required by the Endangered Species Act.”