- The Washington Times - Thursday, August 22, 2002

Maryland officials yesterday defended the use of a highly toxic compound to kill the exotic snakehead fish in a Crofton pond despite previous environmental problems with the chemical.
Department of Natural Resources and Anne Arundel County officials said there was no chance Maryland would experience the kind of problems that rotenone, a chemical used to kill fish, caused in Plumas County, Calif., where the poisoning of Lake Davis to rid it of northern pike led to groundwater contamination and a lawsuit that cost the state $9.2 million.
"Believe me, we are well aware of the Lake Davis situation," DNR spokeswoman Heather Lynch said. "In that situation, the rotenone got into the groundwater supply. We have made every effort and done the research to make sure that doesn't happen here."
State wildlife officials want to eradicate the snakehead, a predatory fish indigenous to China that can breathe air and crawl across the ground on its fins, because it threatens native species and could introduce foreign disease or parasites.
When California authorities treated Lake Davis with 50,000 pounds of rotenone in 1997, the poison killed many of the unwanted pike but it also wiped out every fish for five miles downstream and destroyed the drinking water supply in Portola. Five years later, the northern pike is back in Lake Davis, a fishing resort destination in Northern California.
California wildlife officials said rotenone didn't kill off all the pike because the lake was too deep and too cold when the poison was introduced.
"I would just tell you to make sure where the aquifers are and is there any connection to groundwater supplies," said Fran Roudebush, chairman of the Lake Davis Steering Committee that once again is tackling the pike problem and trying to preserve the fishing resort.
As in Maryland, residents around Lake Davis were told rotenone quickly breaks down and dissipates in the environment, with a half-life of about 48 hours.
But the rotenone mixture used in California contained chemicals such as TCE, benzene and others that lasted much longer. "Some very nasty chemicals," Miss Roudebush said.
Eric Schwaab, director of fisheries service for the Maryland DNR, said the brand of rotenone used in Crofton would be Prenfish, not the Nusyn-Noxfish used in Lake Davis. He said the mixture did not contain the chemicals that lingered in Lake Davis.
"Obviously there are concerns whenever you talk about introducing chemicals of any sort," he said, adding that the scientific panel that recommended using rotenone considered all the potential downsides.
Maryland officials also said it was nearly impossible for the poison to reach nearby Little Patuxent River or the deep wells feeding the county water system, and the two closest private wells also are at a safe distance.
They said the pond, a flooded sand-and-gravel quarry, traps water but doesn't release it to the larger ecosystem.
The Maryland Geological Survey and the Maryland Department of the Environment evaluated the movement of aquifers related to the pond and determined the poison would not migrate, DNR spokesman John Surrick said.
"We have deemed there is absolutely no threat to the public water supply," Anne Arundel County Heath Department spokeswoman Pam Jordan said. "There isn't any way water can escape from that pond."
Mr. Schwaab said there were practically no similarities between the California lake and the Maryland pond. Lake Davis is a 4,000-acre reservoir that feeds a public water system. The Crofton four-acre pond is just 10-feet deep and completely isolated.
"I spoke personally with director of fish and wildlife [in California]," Mr. Schwaab said.
"Frankly, there are no parallels at all, except that we are trying to eradicate a fish. The situation that they had was infinitely more complex than the situation we are dealing with."
Nevertheless, the idea of poisoning the pond doesn't sit well with everyone.
Joe Gillespie, the Crofton engineer who touched off Maryland's snakehead mania in June when he caught one in the pond, said he wasn't so sure poisoning the fish with rotenone was the best idea, considering the fact that Maryland authorities hadn't done anything like that in decades.
"I think they should put up a fence and some netting and let people fish the pond, not worry about poisoning the water," Mr. Gillespie said.
"They are supposed to taste pretty good too," he said. "The landowner could charge a fishing fee."
Meanwhile, Virginia wildlife officials today will propose a ban on the import, possession, cultivation and sale of the snakehead without a special permit. Sixteen other states have such laws.
The Maryland scientific panel that recommended the rotenone poisoning also has proposed laws to stop a repeat of this summer's "Frankenfish" saga.
Natural resources officers continued yesterday to closely monitor the effect of herbicides on the pond known to contain an adult snakehead and perhaps thousands of snakehead babies, as well as two smaller ponds nearby where no snakeheads have been found.
The officers found that three days of poisoning the pond with herbicides had not yet killed much of the vegetation.
Not until after the vegetation dies, probably in about a week, will the department pour about 15 gallons of a 5 percent rotenone solution into the pond.

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