Las Vegas Sun

March 18, 2024

Get rid of pest? Not if it turns tap water pink

Aesthetics have gotten in the way of battling one of the most serious threats to the Southwest's waterways, the fast-spreading, pipe-clogging quagga mussel.

Who wants to drink pink tap water?

Scientists have found that potassium permanganate, a chemical used to combat fish disease, will kill the pesky mussel that showed up at Lake Mead's Boulder Basin in January and has since infested Lakes Mead and Mohave and spread to the lower Colorado River, threatening water systems in Arizona and California.

However, when oxygen combines with potassium permanganate at water purification plants, it gives water a pinkish tint, said Peggy Roefer, a microbiologist for the Southern Nevada Water Authority Water and an expert on the thumbnail-size quagga, a native of the Ukraine.

Even though it would not be harmful, "no one wants to drink pink water," she said.

So, in the struggle to reverse the spread of the quagga mussel, potassium permanganate isn't really an option.

And that means in the campaign to quash the quagga, all eyes return to Daniel Molloy , a singularly focused government scientist who lives in a cabin in the woods of upstate New York and rides his bicycle nine miles to his field research laboratory - a one-time fish hatchery - near Albany.

For the past 16 years - after the pesky mussels showed up without welcome in the Great Lakes from Europe - Molloy has been on the hunt for a way to get rid of them. He says he's closing in on the kill.

Molloy has found a strain of bacteria that is toxic to quagga and zebra mussels - they're almost the same - while apparently sparing the environment around it.

Thus far, the bacteria has been tested against three kinds of fish, seven bivalve species, six kinds of freshwater mussels and a tiny protozoan. All survived the bacteria. The quaggas did not.

"So far, so good," said Molloy, who's still got a lot more testing to do.

He's skilled as a bacteria-armed assassin. He identified bacteria that kills black flies while leaving the rest of the ecosystem undisturbed. In New York's Adirondacks, where the gnat-size black flies swarm, the bacteria is introduced into streams to kill the fly larvae.

Molloy, 59, hopes the federal Environmental Protection Agency registers the pesticide in the next two years. By 2010 it could be available commercially. Molloy wouldn't get an extra penny for his research efforts, because he's on the government dime.

But it wouldn't mean that Lake Mead, the Colorado River or other waterways would be magically cleaned of the mussels.

The bacteria are intended to be injected into pipes where the mussels congregate, gumming up the works of water intake and discharge systems. But it wouldn't be feasible to try to use the bacteria for a wholesale attack on the quagga mussels, he said.

Government officials say Lake Mead and Lake Mohave are so infested with the quagga they likely will never be eradicated.

"Our responsibility now is to try to prevent the spread to the rest of the western United States," said Kent Turner, a biologist and chief of resource management at Lake Mead National Recreation Area.

To that end, rangers from the start have been working with marina operators to inspect all boats leaving the docks, and to clean the ones that have the mussels clinging to them.

Southern Nevada Water Authority officials are focusing their efforts on keeping their water intake lines clear of the mussels. That's where Molloy's bacteria warfare may eventually play out.

In the meantime, water officials are adding common chlorine at water intake sites to discourage the quagga from settling .

At least two dozen local, state and federal agencies and scientists from across the country are involved in Southern Nevada's battle against the quagga.

But except for Molloy's promising work, there have been no answers, and the spread of zebra and quagga mussels has the makings of a horror flick - the tiny mussel spreading around the world, hitchhiking on the bottoms and in the bilge pumps of boats from lake to lake to lake, jeopardizing the water works that serve tens of millions of people in the Southwest alone.

The quagga mussel arrived in the United States about 20 years ago. In the East, the species has caused billions of dollars in damage to water systems and triggered ecological imbalances in rivers and lakes.

But the jury is still out on what the quagga is doing to fish at Lake Mead.

"Our biggest concern is how the quagga will affect the food chain," said Jon Sjoberg, supervising fisheries biologist at the Nevada Department of Wildlife. "We just now are starting to develop that baseline."

There had been anxiety that a large quagga population would consume so much plankton that large numbers of shad fish - the main food source for top-level predators like the striped bass - would starve, leading to the demise of the bass as well.

However, a study of shad in local lakes this spring found no significant changes in their numbers, Sjoberg said. The sample counting of lake game fish this fall might produce some answers.

Sjoberg said if the numbers of bass and other large species are down it will be difficult to determine whether it was caused by quagga or by the shrinkage of the lake caused by the seven-year drought.

There's enough urgency in addressing the quagga infestation that researchers are trying to find a way to use potassium permanganate without turning the water a salmon-pink hue.

If success eludes them, there's always the promise of bacteria strain CL145A. CL stands for Cambridge Laboratory, the place in the woods of upstate New York where Daniel Molloy pedals his bike to work every day.