UA Biologists Find Endangered Fish

TUSCALOOSA, Ala. ­ A team of University of Alabama biologists found a pair of endangered fish feared to be extinct and, as a result, more than a dozen of the tiny, whiskered swimmers are now being successfully raised in captivity with hopes of revitalizing the species.

Dr. Richard Mayden, a UA professor of biological sciences; Bernard Kuhajda, the collections manager; Phillip Harris, a research assistant; and two graduate students, David Neely and Steve Powers, found and collected the pair of federally endangered fish, known as pygmy madtoms, in the Clinch River in Hancock County, Tenn. The biologists promptly contacted a Knoxville, Tenn. fish conservation group they had been working with.

“When we called them, they didn’t believe us at first,” Mayden said. “They thought we were joking. We said, ‘we got two of them, just like you wanted ­ male and female.'”

It’s no wonder the group, Conservation Fisheries, Inc., thought the UA scientists were kidding. The fish are considered one of the rarest species of North American fishes. Only two places in the world ­ the Clinch and Duck rivers ­ both in Tennessee, are known to serve as home to the brown and white fish, and fewer than 30 of the fish have ever been collected; none spotted since 1996, according to J.R. Shute, a co-director at the fishery.

“There have been very few specimens taken since the mid-80s,” Shute said. “We went back through all the TVA’s (Tennessee Valley Authority) records trying to find how many of these guys have been collected ever, and it was about 25 specimens. They are very difficult to observe and very difficult to collect.”

The captured fish, unbeknownst to the UA scientists, really were male and female and, after two successful spawns, the pair of fish now have 13 seemingly healthy offspring living in the fishery.

“We have talked with the Fish and Wildlife Service at length about the hope of getting pygmy madtoms into a reintroduction effort,” Shute said. “In the meantime, it’s nice to have a little population ark for them.”

Fish, such as the one and three-quarter inch pygmy madtom, which are not popular among recreational or commercial fishers, are often ignored, said Mayden. “There are lots of game species that everyone is interested in fishing for, and they are reared in hatcheries, and their populations are being augmented from hatcheries,” Mayden said. “But, rarely do you find non-game species being propagated in captivity and then being restocked.”

Restocking a fish on the verge of becoming extinct is a temporary solution, and Mayden called that effort alone, a “Band-Aid” approach. “We want to identify what the problems are and remedy them,” Mayden said.

It’s been speculated that contamination of the river, including a chemical spill that occurred a few years ago and increases in fertilizer and herbicide run-off, has negatively impacted organisms in the water, Mayden said.

Another possible factor that has been cited in the fish’s continued decline is an increase in siltation in the river’s bottom. The pygmy madtom lays its eggs within the spaces between tiny rock pebbles at the water’s bottom. Run off of dirt and clay can clog the spaces between the pebbles, leaving no place for the eggs.

One way to reduce such erosion problems is to leave “green lines” or naturally occurring plant life, around rivers as a buffer zone, Kuhajda said.

“You don’t stop developing, you don’t stop harvesting timber, but you just try to develop zones around the stream system so the impact of development isn’t as great,” Kuhajda said.

There are various reasons why society should care about the fate of fish like the pygmy madtom, Mayden said.

“This species is unique to our part of the world,” Mayden said. “It’s not found any place else. This is our natural heritage, and we should protect it.”

The fish’s peril could point to other problems, he said.

“Usually aquatic organisms react first to environmental disturbances,” Mayden said. “These fish are indicators ­ sort of a yardstick ­ of what our water quality is. When we start to see these things disappearing, that’s an indication that things are changing in the surrounding environment that we depend on.”