The threatened Pearl River darter (Percina aurora) has not been recorded in its namesake river for 40 years, according to the U.S. Fish & Wildlife Service. But now, the service is attempting to reestablish the itsy-bitsy vertebrate in its native waters.
“This is the biggest win of my career as a biologist so far,” Matt Wagner, a U.S. Fish and Wildlife Service biologist, told the AP. “It’s very seldom that you get to restore a species back to its historic range. As a biologist, when you go to school, this is the type of day you’re all dreaming about.”
Darters are a group of about 100 freshwater ray-finned fish in the family Percidae. All darters are native to eastern North America, and get their name from—you guessed it—darting around the river bottoms they inhabit. According to the IUCN’s Red List, numerous darter species are becoming threatened by habitat loss.
“There’s more species here than most other places, and a lot of the species that we find here are what we call sensitive species,” Wagner told the AP. “They are species that are not very tolerant of things like pollution, high disturbance and things of that nature.”
The bottom-dwelling Pearl River darter is protected under the Endangered Species Act of 1973. The animal measures about 2.5 inches (6.35 centimetres) long, though some darters grow up to 9 inches (23 cm) long. The fish disappeared from the Pearl River and Pascagoula drainage systems of Louisiana and Mississippi due to pollution from oil and gas development, agricultural runoff, dam construction, and urban pollution, the AP reported.
According to the U.S. Fish & Wildlife Service, scattered populations of the fish are in genetic bottlenecks, meaning the animals are particularly vulnerable to events like droughts or pollutive events.
In 2021, the service proposed over 500 miles (805 kilometres) of river in Mississippi as critical habitat for the fish, to ensure its recovery and, with any luck, its removal from the Endangered Species List. Critical habitat is the geographic area earmarked for the species’ eventual footprint. The rule establishing critical habitat along the waterways—494 miles of it in the Pascagoula drainage system and 30 miles of it in the nearby Strong River—went into effect May 8, 2023.
The road to recovery may be long, but the darter has taken the first teeny steps—erm, strokes—towards reestablishing itself in the waterways of the American Southeast.