Students clean curtain of algae off Tuscora Park pond
A hydraulic mini-dredger is being used to clean about 2 feet of sedimentation off the bottom of the lagoon that feeds the pond. The top layer of algae and duckweed also will be cleared away.
Students from John Oliver’s natural resource management class at Buckeye Career Center spent a day and a half raking a heavy layer of algae off the surface of the pond at Tuscora Park last week. It was the first step in a three-part process to save the pond and the wildlife that inhabit it.
Accompanying the algae was a good bit of duckweed — vegetation that gets dragged into the pond by water fowl — which also was skimmed off.
“It looks a lot better already,” said Ron McAbier, New Philadelphia service director. “But we’ve got a way to go.”
“Having the students out here working is a win-win for the city,” said Alec Hillyer, owner of Dynamic Lake and Land Management in Dundee, who has been hired by the city to clean the pond. “It saves the city money on manpower. It’s great for the students because they’re in the natural resources program, so it’s good, relevant experience for them, and it’s the best first step for the pond.”
The first inklings that something might be wrong with the pond surfaced around June of this year when a thick layer of filamentous algae started collecting and matting together. But that wasn’t the problem. It was a symptom, according to Hillyer.
The deeper problem was something called eutrophication. “There are too many nutrients feeding the algae at the bottom of the pond,” Hillyer said.
The reason there are too many nutrients is it is a shallow pond where light can reach the bottom depths.
The Tuscora Park pond is estimated to be no more than 5 feet deep. According to Oliver, a typical pond has a benthic (lower) and a photic (upper) level where photosynthesis of plant life takes place. Because the pond is so shallow, the entire pond is photic.
This means light goes all the way to the bottom of the pond, creating too much plant growth. Plants die and float to the surface as they decompose.
A delicate balance
Treating the pond to prevent future incidents such as this one requires understanding delicately balanced ecosystems. “There are no magic bullets when managing resources,” Oliver said.
Hillyer is hoping his proactive plan is nearly magic, though. He has added a layer of dye to help prevent light from reaching the bottom of the pond. He also has introduced an aeration system and alum to bond with phosphate and slow down plant growth.
“Instead of just treating the algae on the top and letting it sink and grow again, I want to stop it from ever getting to this point again in the first place,” Hillyer said.
A “fishy” solution
Last Friday Hillyer placed about 50 sterile grass carp into the pond. A sterile version of the Asian white amur, these fish are being used across the country as a natural method of controlling aquatic plant growth as opposed to using more expensive and potentially harmful chemicals.
The fish will feed on the vegetation and help prevent overgrowth. “Sterile grass carp are very good at what they do, and what they do is eat,” Hillyer said. “Everything is photic here, so amurs are an absolute must. It will save the city a tremendous amount of money in the long run.”
Dredging the lagoon
While Hillyer and others have been devoting their attention to the pond, Paragon Integrated Services Group of Newcomerstown began addressing problems in the lagoon that feeds the pond last Friday morning.
Ed Moyer, technical sales engineer for Paragon, said the lagoon clean-up could take up to 30 days. He explained that a robotic mini dredge will run from edge to edge the entire length of the lagoon to remove anywhere from 18 inches to 2 feet of sedimentation off the bottom. Duckweed will be skimmed off the surface at the same time.
“The biggest issue is that the lagoon is only about 3 1/2 feet deep, so it has the same problem as the pond,” Moyer said. “And I believe the last time the lagoon was cleaned was around 1998.”
Moyer said they are not using any chemicals in the clean-up. “We’re just doing hydraulic dredging, and a big pump will suck it all up,” he said. “Then we’ll run the water across shale shakers, and all the fluid that goes through the fine screens on the shale shakers goes into a tank. We’ll pull water through a high-speed centrifuge before returning clean water into the lagoon.”
According to Moyer, the benefit of using this method is twofold: There will be no harm to wildlife, and the lagoon can continue functioning while it’s being cleaned.
On Sunday, Oct. 3, Hillyer said he had to treat some of the active growth on the algae that kept cropping up, using a weak form of copper as an algaecide to slow or negate new growth.
“I looked at the forecast for next week, and it’s going to get warm,” Hillyer said, noting warm temperatures could cause more growth. “In conjunction with the rain Sunday night, there’s still a lot of growth. As of Monday morning, the water rose 6 inches, so we’ll start lowering the water level. Next year we will probably deal with this again. It won’t get better overnight. But after a year or two, it should straighten out. It just may be a little rocky until then.”