Fishing for flies

The stonefly is back on the South River, and the reason for its return is a big deal.

“They’re sensitive to water pollution, so finding those are good,” Calvin Jordan, a South River mercury scientist for the Department of Environmental Quality, said Thursday. “We’d like to find more of those.”

Urbie Nash of Trout Unlimited agreed.

“Finding those kinds of insects is a very encouraging sign in the middle of Waynesboro,” Nash said. “Far too many people think that the river is ruined and you have these industries discharging all these toxic wastes, and that is absolutely not the case.”

Stoneflies live in the cracks between rocks that fill with sediment in polluted streams. When that happens, stoneflies are among the first to go, a frequent occurrence in waterways like the South River during the era of unregulated industry in the first half of the last century.

Jordan and Nash on Thursday morning hailed the discovery of the fragile insects’ re-emergence in the South as volunteers gathered on the river with about 250 sixth-graders from Kate Collins Middle School helping them learn about aquatic life through a series of interactive activities. 

Many of the same things the students got to experience will be a part of Saturday’s Riverfest at Constitution Park.

Nash explained that industrial plants in the past “were clearly impacting the river” but now their impact is minimal compared to runoff from farms and impervious surfaces. 

Jordan said the stonefly likes to live in colder water because it can hold more oxygen, whereas the oxygen dissipates in warmer weather.

He and the students found a number of other fly species on the water – mayflies, cattus flies and the fishfly among them. They also found water penny beetles, a family of aquatic beetles; leeches; snails, scuds – a common crustacean – crayfish and different kinds of worms.

Nash, who also is a member of the Riverfest board of directors, said in water testing done yesterday, he and the students found no phosphates but a little bit of nitrate in the river. That, he said is likely from non-point sources such as fertilizer runoff.

“It’s not an alarming amount of nitrate,” Nash said. 

The students collected a large variety of minnows, bottom fish and game fish in the river, Nash said.

During Saturday’s free Riverfest, people can watch a stream electro-fishing demonstration and interpretation of up to 20 species that will be displayed in a riverside aquarium.

Johnson said the biggest problem with the river – mercury – will take the longest to solve and will likely involve “a multitude of solutions.”

He said the bacteria in the river sediment changes the form of mercury, called methylation. If that process can be interrupted, “you could solve a lot of problems,” Johnson said, “not [only] here but everywhere. But that’s a long ways off.”

Later this year, Johnson said DuPont will likely lead a bank stabilization project in the area of the Invista plant – which formerly belonged to the Delaware-based company. DuPont used mercury as a catalyst in its fiber production from 1929 to 1950. In November 2000, DuPont and DEQ established the South River Science Team, a group of people from a variety of backgrounds, to study mercury pollution’s consequences and find remedies for it.

Johnson also hopes wildlife can be studied to determine how it has been affected by mercury.

Nash, meanwhile, hopes the public can experience the students’ excitement for life on the river during Riverfest.

“It’s a great family event,” Nash said, “and the kids love it.”