The southeast United States is a place of unparalleled aquatic biodiversity, harboring 493 fishes (62% of U.S. fish species), at least 269 mussels (91% of U.S. mussel species), and 241 dragonflies and damselflies (48% of all those in North America). The Southeast also contains more than two-thirds of North America's species and subspecies of crayfishes and more amphibians and aquatic reptiles than any other region.

All things considered, it has the richest variety of aquatic fauna of any temperate area in the world, rivaling the tropics. This biodiversity is remarkable not only for its breadth but for the fascinating adaptations its myriad species have adopted. For example, a group of southeastern fish called darters talk to each other, the males using underwater knocks, groans and purrs to communicate during courtship and spawning to fight off other males and attract females. The region's salamander mussel is the only mussel in the world that uses a salamander — the mudpuppy — instead of a fish to host its larvae. One Southeast wetlands plant, the carnivorous Wherry's sweet pitcher plant, traps insects using a rolled leaf and consumes them with digestive fluids once they've fallen to their doom at the bottom of its tubelike pitcher.

Unfortunately, the Southeast's staggering variety of freshwater life forms and their habitat also make up one of the most imperiled ecosystems on the planet. Thanks to pollution, development, logging, poor agricultural practices, dams, mining, invasive species and other threats, extinction is looming for more than 28% of the region's fishes, more than 48% of its crayfishes and more than 70% of its mussels. As just one example of a Southeast waterway in peril, the Coosa River is the site of the greatest modern extinction event in North America, where 36 species went extinct following the construction of a series of dams. Overall the Mobile Basin is home to half of all the North American species that have gone extinct since European settlement.

And yet Southeast aquatic species are some of the country's least protected. Most of them aren't on the endangered species list or safeguarded by any other law.


With so much at stake, it's imperative that these animals and plants receive federal safeguards — and the Center has been leading this work for more than a decade. Back in 2010 we filed our scientific petition to list 404 Southeast aquatic, riparian and wetland species as threatened or endangered. Since then the petition has resulted in dozens of species getting federal protection.

We also made a landmark agreement with the U.S. Fish and Wildlife Service compelling the agency to move forward in the protection process for 757 of the country's most imperiled, least protected plants and animals — including hundreds of Southeast species we'd petitioned for. Soon after our agreement, the Service protected five southeastern fish species and was moving forward on protection decisions for no fewer than 374 Southeast freshwater species in 12 states, from Florida sandhill cranes to Alabama map turtles.

In 2013 the Service finalized Endangered Species Act protection for two species of freshwater mussels in the Tennessee River watershed — slabside pearlymussels and fluted kidneyshells — as well as 1,380 river miles of critical habitat.

In recent years the Center has helped win federal protection for more Southeast aquatic species, including salamanders like Neuse River waterdogs and Ozark hellbenders; Guyandotte River and Big Sandy River crayfishes; magnificent ramshorn snails; several species of fish, including frecklebelly madtoms, Carolina madtoms, Barrens topminnows, Pearl darters, and sickle darters; and more than a dozen mussels, including pyramid pigtoes, southern elktoes, Ouachita fanshells, longsolids, and round hickorynuts.

The Center has secured thousands of river miles of critical habitat for these species, and we’re still fighting for more protections and to make sure protections are enforced. In 2022 we halted dredging that would have destroyed the habitat of orangefoot pimpleback, rabbitsfoot, and sheepnose mussels.

We’ve petitioned to protect Big Darby Creek under the Clean Water Act to help save six federally protected mussels. We’re also advocating to protect the Okefenokee National Wildlife Refuge — the largest blackwater swamp in the United States — from a proposed titanium mine next door. We’re fighting to save the federally listed Canoe Creek clubshell mussel from dams, endangered crayfish from coal mining, and candy darters from pipelines.

All Southeast aquatic species are intricately interconnected. For example, map turtles' survival depends on an abundance of snails and mussels, which they eat, while mussels depend on fish to host their larvae — and the fish, in turn, depend on the abundance of flies, whose larvae they consume. Protecting all these species will help save their entire, extraordinary ecosystem from unraveling before it’s too late.

Check out our press releases to learn more about the Center's actions to save Southeast freshwater species.

Trispot darter photo © Bernard Kuhajda.