By Mannix Porterfield
Register-Herald reporter
May 31, 2008 10:44 pm
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An environmental leader in Hinton says the spraying of Bti to control the annoying black fly population in southern West Virginia indirectly is causing fish in the New River to become infested with tapeworms.
Save Our Mountains president Richard Smith blames the tapeworms on hellgrammites and other invertebrates ingesting the feces of Canadian geese, in the absence of black fly larvae, in the world’s second-oldest stream.
Bti is applied through the spring and summer months to keep black flies in check along the New, Bluestone and Greenbrier rivers.
Veteran anglers and Smith’s organization have long opposed the practice, claiming the Bti disrupts the natural food chain.
A bait distributor opened up a bass recently and found it crawling with tapeworms, making it unfit for consumption, Smith said.
“Bass in the river have got worms,” Smith said Thursday. “You can’t eat them. You see these big tapeworms in them if you cut them open.”
Terry Carrington, the survey entomologist and former black fly program coordinator for the state Department of Agriculture, disputed this, saying that not all larvae are eliminated, but rather the spraying is intended to merely control populations.
“There are still black fly larvae in there, or else we wouldn’t have to spray seven to 10 times this time of year,” he said.
“We could just spray once and they’d all be gone. There are plenty of other aquatic insects in there for hellgrammites to eat. They’re not dependent solely on black fly larvae. I don’t know if hellgrammites are known to vector tapeworms from geese into bass. He just really is tying together totally unrelated things and blaming it on Bti spray is what it boils down to.”
Besides, Carrington said, hellgrammites simply won’t dine on any kind of feces, including that deposited by the geese.
“They have to eat other animals,” he said.
By eliminating a large portion of the natural food chain in spraying for black fly larvae, Smith said, the program has left those at the bottom with no alternative but to feast on the feces deposited by the geese.
“There are big flocks down here,” he said. “They’re all over. You see the kind of mess they make. Just think what they can do in the river. The Bti has eliminated the food chain in the river so the other elements, the hellgrammites and the crayfish, are eating feces, and the fish are getting worms.”
Smith also alleges the helicopter pilot under contract with the state Department of Agriculture to do the spraying is dropping Bti into the water intake of the city of Hinton.
“They spray directly into the intake and the people of Hinton are actually drinking Bti,” he said. “I think they ought to stop spraying the water intakes. That is no good.”
Carrington acknowledged it’s possible some Bti makes its way into the city’s water system, “but at the rates we use — 11 parts per million — it wouldn’t be harmful.”
Bti is employed to treat sewage plants by controlling mosquitoes and eventually gets into the water table, he pointed out.
Any that finds its way into a water system would be eliminated during the treatment process, Carrington said.
“It would settle out in the settling tanks,” he said. “It wouldn’t even make it to the taps.”
— E-mail: mannix@register-herald.com
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