THE SOUTHEAST FRESHWATER EXTINCTION CRISIS
The southeast United States is a place of unparalleled aquatic biodiversity, harboring 493 fishes (62 percent of U.S. fish species), at least 269 mussels (91 percent of U.S. mussel species), and 241 dragonflies and damselflies (48 percent 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 aquatic fauna of any temperate area in the world, rivaling the tropics. In its mere 190 miles, for example, the Cahaba River harbors 125 species of fish, 50 species of mussel and 15 species of crayfish.
This biodiversity is remarkable not only for its breadth, but for the fascinating adaptations its myriad species have adopted. For example, in the Southeast, a group of 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 percent of the region’s fishes, more than 48 percent of its crayfishes and more than 70 percent 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 North American species that have gone extinct since European settlement.
And yet Southeast aquatic species are some of the country’s least protected. The majority of them aren’t on the endangered species list or safeguarded by any other law.
In other 2010 Southeast action, we filed suit to speed protections for three comically named but seriously endangered southeastern mussels — the Georgia pigtoe, interrupted rocksnail and rough hornsnail. The Fish and Wildlife Service finalized safeguards for those three in early November 2010, also designating 160 river miles of critical habitat.
With so much at stake, it’s imperative that these animals and plants receive federal safeguards very soon — and the Center is making sure they will. In the summer of 2011, we struck a landmark settlement with the 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; then, in September, the agency announced it was moving forward on protection decisions for no fewer than 374 Southeast freshwater species in 12 states, from the Florida sandhill crane to the Alabama map turtle. Most recently, the Service proposed to safeguard eight species of freshwater mussels in Alabama and Florida and has finalized protections for two mussels found in the Southeast and elsewhere — the sheepnose and spectaclecase mussels.
The 2011 settlement and subsequent success didn’t come without a lot of previous work by the Center. We filed our scientific petition to list 404 Southeast aquatic, riparian and wetland species as threatened or endangered in 2010. Almost a year later, the Obama administration had finally made a decision on only one of the 404 species, the Alabama shad — and it chose not to protect the rare fish. In April 2011, we filed a notice of intent to sue the U.S. Fish and Wildlife Service over the shad, in addition to a notice over the Service’s failure to move forward on the other 403 species. And though it was a great victory to force the Service to make progress on 374 Southeast species in 2011, we're still pushing to protect the other 29 species we petitioned for, too. In July 2012, the Center filed a notice of intent to sue the Service for failure to protect the Obey crayfish under the Endangered Species Act.
All Southeast aquatic species are intricately interconnected. For example, the map turtles’ survival depends on the 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 through a group approach will help save their entire amazing ecosystem from unraveling before it’s too late.