TVA aquatic biologists recently identified a new fish species in tributary streams to the Duck River.
The Tennessee logperch (Percina apina) is a darter discovered inhabiting cool water streams that drain into the Tennessee River in Middle Tennessee.
The discovery was announced in the October issue of the Bulletin of the Peabody Museum of Natural History in the article “New Species of Logperch Endemic to Tennessee.”
According to TVA aquatic biologist and study co-author Jeff Simmons, the species may have been around for a while, its existence being noted as far back as 1971. Back then, it was recognized as another population of the blotchside logperch (Percina burtoni).
Through persistent field study and help from modern technology, Simmons and others were able to prove definitively that the Tennessee logperch is a distinct species. Thus, what was already North America’s most biologically diverse river system, the Tennessee, grew even more biologically diverse.
“Our group monitors water quality throughout the Tennessee River system,” Simmons said. “We do that by using fish and insect communities to assess stream health. Based on what we find, we assign a score to each stream—and we have over 700 sites throughout the valley. That allows us over time to contribute to science as far as updates on rare and endangered species.”
Simmons has been monitoring the blotchside logperch since 2013, when he spotted one in the Big South Fork National River in a location where they were thought to be extirpated.
“Nobody had seen one since 1980,” he said. “A lot of people didn’t believe me, but I started talking to Tom Near at Yale University [Simmons’ co-author on the Tennessee logperch study], and it opened the door to investigating the group of fish as a whole.”
A 2006 study had noted that whereas all the logperch in the Duck River system tributaries had eight to 10 black spots running down the sides of their bodies, in some they were taller than wider and in others wider than taller. This led Simmons and Near to wonder if they could be different fish. Years of study and later DNA testing concluded that they were, indeed, different species.
According to Simmons, the Tennessee logperch is a delicate, somewhat-finicky species.
“It’s a sensitive fish that uses its snout to flip small stones on the creek bed to feed on caddisflies and other sensitive aquatic insects,” he said. “It’s a sight feeder, too. It couldn’t exist in muddy water or polluted water or streams where excess sediments covered the creek bed, smothering the insects that the fish eat.”
Thus, the existence of the Tennessee logperch is an indication that the water quality in that part of the Tennessee Valley is good.
Though the population of the new fish is limited, it isn’t endangered, Simmons said:
It is distributed in a small area, but the water quality is in good shape. Unless the water quality sees a rapid decline, there’s no reason to list it as endangered. This is the only logperch species endemic to Tennessee, and though you might not see it right away, there is a web of other species that are interconnected to it. Keeping our water clean, keeping this fish alive—this is our natural heritage. This is what we have to pass down to the next generation.
Clean water is one factor contributing to the results of a 2017 University of Tennessee Institute of Agriculture study, which found that the value of recreation on TVA’s reservoirs is worth about $12 billion per year to the regional economy.