Killer fish won't say die

Snakehead: A herbicide cocktail is slow to rid the infestation at a Crofton pond. The creatures are still alive.

August 31, 2002|By Stephen Kiehl | Stephen Kiehl,SUN STAFF

The fish live.

Two months after Crofton's snakehead infestation became an international sensation, one month after a panel of experts picked its poison to flush the fish from the pond, and almost two weeks after a herbicide cocktail was sprayed over the water, the fish are still biting.

"There are still fish alive in the pond," John Surrick, a Department of Natural Resources spokesman who was at the pond yesterday, said ominously. "You can see them scatter as birds swoop across the surface."

Twice a day for the last two weeks, DNR biologists have visited the pond off Route 3 to see if any of the hundreds of snakeheads believed to be lurking in the weed-choked water have died and floated to the surface. None has.

The herbicides applied Aug. 18 - diquat dibromide and glyphosate - have not worked as quickly as hoped, and the 4-acre pond still teems with green plant life. Experts had expected the plants to be dead in seven to 10 days, but because the growing season has ended, they say it will take much longer.

"We were hoping that when the plants started to back down, it would take the oxygen out of the water and kill the fish," said Paul Genovese, a DNR biologist who was checking the pond yesterday. "That obviously hasn't happened."

But officials are not terribly disappointed. They note that the herbicide application is the first of two steps designed to rid the pond of the land-walking, fish-devouring, fear-inducing snakeheads. The real purpose of the herbicides is not to suffocate the fish, but to clear the water so that when they die, they'll be easy to spot.

The second step of the extermination is applying rotenone, a fish poison that can be effective even in heavy vegetation. As early as the middle of next week, officials plan to spray up to 18 gallons of rotenone over the surface of the pond, which is tucked behind a Dunkin' Donuts and a strip mall.

Within several hours of the rotenone application, the snakeheads - and anything else that's still alive in the pond - should be dead.

Crofton residents, who have watched the fish story that wouldn't die draw media hordes to their small town, are also surprised that the fish haven't died.

"I'd like to be rid of them," said Marianna Rizzo, who was enjoying her morning coffee and sesame seed bagel at the nearby Dunkin' Donuts. "It's a problem. It's an infestation. Let's be aggressive and knock 'em dead."

DNR officials say they've moved as fast as possible. When the northern snakehead fish was first positively identified in the nameless Crofton pond in June, the agency formed a 14-member panel of experts to plot a course of extermination. In late July, the panel recommended using two batches of chemicals on the pond - first the herbicides, then the pesticide.

But before that could happen, owners of the snakehead-infested pond and two smaller, nearby ponds had to give their consent. Those negotiations took several weeks.

All the while, officials worried that the torpedo-shaped snakeheads, which can slither on land and survive out of water for up to three days, would mosey on over to the Little Patuxent River, just 75 yards from their pond.

A silt fence was set up on the side of the pond facing the river, to catch the fish.

Once the rotenone is applied, the dead fish will be skimmed from the surface and taken to the Anne Arundel County dump in Millersville.

Then DNR will put caged sentinel fish in the pond to see if the rotenone has worn off. When the sentinel fish survive, the pond will get a clean bill of health.

"It was not a healthy pond to begin with," Surrick said, standing inside a yellow police line on the pond's muddy banks.

The pond was still and the water was cloudy from recent rain. The snakeheads, it seemed, were lying low, conserving their strength for the final onslaught.

Baltimore Sun Articles
|
|
|
Please note the green-lined linked article text has been applied commercially without any involvement from our newsroom editors, reporters or any other editorial staff.