(CN) — A freshwater mussel found only in North Carolina and Virginia won federal protection Monday after waiting nearly 30 years.
The U.S. Fish and Wildlife Service finalized a rule that lists the Atlantic pigtoe mussel as a threatened species under the Endangered Species Act of 1973.
In addition to the listing, the rule designates a critical habitat for the species in portions of 12 counties in Virginia and 17 counties in North Carolina.
Once ranging from the Ogeechee River basin in Georgia to the James River basin in Virginia, this 2-inch-long mussel has been entirely eradicated from Georgia and South Carolina and has disappeared from more than 60% of its former range.
Just a handful of them still survive in most locations, according to the Center for Biological Diversity, and only three populations are considered healthy.
“After so many years of foot-dragging by the Fish and Wildlife Service, it’s a relief to finally see the Atlantic pigtoe protected under the Endangered Species Act,” Perrin de Jong, an Asheville-based staff attorney for the group, said in a statement on Monday.
The final rule allocates a total of about 563 river miles to the species’ critical habitat.
The move comes after years of legal actions filed by the Center for Biological Diversity and other environmental organizations since the Atlantic pigtoe was first identified as needing federal protection in 1991.
The first lawsuit came in 2014, alleging the FWS had failed to protect the species.
After the agency proposed protections for the mussel in 2018, it didn't go through with listing the species, prompting the bivalve advocates to sue again last year.
“The Southeast is the world capital of freshwater mussel biodiversity, and most of these mussels are facing extinction due to the rampant abuse of our rivers and streams,” de Jong said. “Without federal protections, many of these unique and important creatures will vanish forever.”
The Atlantic pigtoe is a yellow to dark-brown mussel often donning streaks across the back of the shell. Its name comes from the shell’s shape, which the FWS describes as appearing “like that of a pig’s hoof.”
In its final rule, the federal wildlife agency says that a combination of environmental factors are causing the mussel’s decline, with habitat degradation being the main problem.
“This stressor primarily consists of habitat changes: the buildup of fine sediments, the loss of flowing water, instream habitat fragmentation, and impairment of water quality, and it is exacerbated by the effects of climate change,” the FWS says, noting that these issues stem from land use change and associated watershed-level effects.
Water pollution from development, agriculture and logging poses the largest threat, according to the Center for Biological Diversity.
Mussels improve water quality by filtering small particles from the water as they eat, making them beneficial to the environment but extra sensitive to water pollution and sedimentation.
Though the American Southeast is the largest hub for freshwater mussel species in the world, environmentalists say 75% of the region’s mussel species are at risk.