NASHVILLE, Tennessee (AP) — It was a crisp fall day when biologist Bernie Kuhajda drove to a nondescript trickle of water running through a cow pasture in central Tennessee to try to save a small, brightly colored fish from extinction.
The trickle—no more than a few large mud puddles—was one of the last bodies of water to have a population of Barren’s top minnowsand it dried up.
So Kuhajda and his team donned waders and dragged a large sieve through the muddy pools, collect 64 of the small, iridescent killifish to take back to the Tennessee Aquarium, where they maintain an “ark population” as a hedge against their possible disappearance in the wild.
“If we hadn’t saved these 64, this entire genetic population of Barrens top minnows would have disappeared,” Kuhajda said. “This species would have been one step closer to extinction, and it’s not many steps away now.”
That was in 2016 and although those fish were rescued, the fate of the species is far from certain.
The Barrens top minnow spent more than 40 years in limbo of endangered species — under an on-and-off assessment in which the fish’s chances of being rescued suffered from the bitterness engendered during a highly publicized battle for a save other small Southeast fish, the snail darter. The thorn is finally given federal protection in 2019but its future is still uncertain, in part because the U.S. Fish and Wildlife Service hasn’t defined its critical habitat — the areas that need to be protected in order to recover.
In recent decades, its distribution has dwindled to a handful of springs and streams around Manchester, where the annual Bonnaroo music festival is held. In that time, it has been both the victim of political opposition to the Endangered Species Act and the beneficiary of massive efforts to prevent its extinction.
One of the champions is biologist Pat Rakes, who researched the Barrens top minnow for his master’s thesis at the University of Tennessee, Knoxville, and is now co-director of the nonprofit Conservation Fisheries. That’s one of different settings that has sustained ark populations. Rakes said there are many good reasons to protect a small fish that many people may find unimportant, and perhaps the best is because all aquatic animals and plants work together to keep the ecosystem healthy.
As Rakes puts it, “You don’t throw away parts when you tinker with the machine, or you might not be able to put it back together.”
Barren’s top minnows grow to about 4 inches (10 centimeters) and live for about three years. They eat insects and small aquatic animals. The breeding males are brightly colored with red-orange spots on an iridescent blue-green body and bluish fins with yellow and black edges.
“They are absolutely beautiful,” said Margaret Townsend. “They look like jewelry, like they’re covered in gems.”
Townsend is an attorney at the Center for Biological Diversity, which recently threatened to sue the conservation agency for failing to identify critical habitats. The agency has asked for patience, writing on Sept. 7 that it is “working diligently” and expects to submit a proposed critical habitat by the end of the year.
Barren’s topminnows are named after where they live – Tennessee’s Barrens Plateau, so named for its relative lack of trees. Small waterfalls and cascades isolate the plateau’s waters, preventing downstream fish from entering the roach’s territory. But sometime in the 1960s or 1970s, the western mosquitofish was introduced in a misguided effort to control mosquitoes — they eat mosquito larvae, but so do Barren’s top minnows. Wherever the mosquitofish has been introduced, the thorn has disappeared.
“They eat all the eggs of the top minnows, all their larvae, and they harass the Barrens top minnow — even though the Barrens top minnow is bigger — and smother their fins off,” Rakes said.
Recognizing the threats of habitat loss from agriculture and development, as well as predation from mosquito fish, the Fish and Wildlife Service first proposed listing the Barrens top minnow as endangered in 1977. That was shortly after the Endangered Species Act was passed. accepted. It was also smack in the middle of the bitter slugfly battle that held up construction of a Tennessee Valley Authority dam for more than two years.
The battle with snail darts weakened the public and political appetite for labeling another small Tennessee fish as endangered. The listing stalled, with the Barrens top minnow occasionally popping up in the state registry over the following decades as being judged.
In the 1990s and 2000s, the Fish and Wildlife Service signed conservation agreements with farmers such as Raymond Cooper who sought to protect the habitat of the fronds by shielding livestock from the few wells where they still lived. Cooper said in a phone interview that he still fenced his livestock even though the deal has expired, because it was the right thing to do “for the sake of the flow.”
“As far as I know, carp fish are still hatching,” he said. “As long as I own the farm, it will be protected. But at 79 years old, I won’t own it forever.”
Barren’s top minnows might have gone extinct if it wasn’t for biologists who had Kuhajda around to collect them, breed them in captivity, and return them to the wild in an effort to restore viable populations.
The battle to save the Barrens top minnow is bigger than just a small fish, Kuhajda said. The American Southeast has the greatest aquatic biodiversity of any kind in the temperate world, with an amazing array of fish, mussels, water snails, crayfish and aquatic insects such as mayflies and dragonflies.
“It’s part of our natural heritage here in the Southeast and most people don’t know about it,” he said. “Most of these animals can’t be found anywhere else than here. It’s something to be proud of.”
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