Examining more than 500 fish from between 25 and 30 species, four biologists floated around on a specially equipped boat that sent an electrical current through the water and temporarily stunned nearby fish.
Referred to as electrofishing, the fish were not harmed, but were examined for abnormalities and released back into the water.
“Fish and aquatic insects are great indicators of the water quality in our reservoirs. When we collect the fish, look at them and look at the entire sample, we’re able to assess the health of the reservoir,” said TVA fisheries biologist Greg Shaffer.
Biologists pulled largemouth bass, bluegill and golden redhorse — among other species — out of the water for examination.
“(The golden redhorse) is a very common fish,” said fisheries biologist John Justice.
“Most people in the public don’t see them because you can’t readily take them on a hook and line. That’s one of the neat things about doing (electrofishing) is we get to showcase a lot of the resources that you typically don’t see by coming out and fishing.”
The observations also included surveying organisms living on the benthic zone, or the bottom of the lake. On a separate dredge boat, two biologists scooped material from the bottom and sifted through it, searching for small invertebrate organisms, such as fingernail clams, non-biting midges and aquatic worms.
“We take 10 equally spaced samples across the width of the reservoir,” said TVA fisheries biologist Susan Malone. “Everything that we find we write down in our data sheet. We keep a tally of the different kinds of organisms ... It helps us to better understand both abundance and diversity of what is living on the reservoir floor. ”
Both the fish and benthic examinations were part of TVA’s Reservoir Ecological Health Program, which also includes testing the water’s dissolved oxygen, chlorophyll and sediment.
Despite historically scoring low on its overall ecological health rating, the TVA biologists said Boone Lake’s aquatic life appeared normal.
“Everything looked perfectly normal,” Shaffer said. “The number of fish, the number of species (and) the kinds of benthic insects are exactly what we’d expect to see. We also saw some good year classes, (including) some small fish, intermediate-size fish and, of course, the larger fish, too.”
The latest ecological health data available in 2011 shows Boone Lake reservoir with poor scores for dissolved oxygen and chlorophyll. Its fish, bottom life and sediment were all scored as being fair.
“As in previous years, the fish community rated fair at all three monitoring locations,” according to the 2011 report on TVA’s website. “TVA did not collect as many species as expected and found relatively few intolerant species (species known to require good water quality conditions).”
Jim Hopson, TVA public relations manager, said the low scores, which were consistent dating back to 1994, was the result of several factors and should not raise any concerns.
“It sounds worse than it actually is,” Hopson said. “The ecology of the lake is actually quite good ... Boone Lake is still a very healthy lake, but it could be healthier.”
Hopson credited the below-average scores to a combination of factors, including over-fertilization on some of the tributaries flowing into the reservoir.
“Obviously, it’s just part of nature. But when you look at fertilization, people washing waste from their driveway that may contain certain elements (and) large quantities of farming, all that adds up and it does challenge (the ecology),” Hopson said.
Hopson said it will be a while before Wednesday’s analysis results will be available. The TVA biologists will conduct the same study on Douglas Lake in November.
Email Zach Vance at firstname.lastname@example.org. Follow Zach Vance on Twitter at @ZachVanceJCP. Like him on Facebook.com/ZachVanceJCP