By David A. Fahrenthold
Washington Post Staff Writer
Saturday, February 13, 2010; B04
To nature, snow is potential. It is rainwater, waiting for a cue. So for now, scientists can guess at the environmental effects of historic back-to-back blizzards: Snowed-in cars don't pollute, snow-drooped trees could temporarily change the architecture of local forests.
But the full impact of this two-act Snowmageddon won't be clear until the stuff melts.
If those 30-plus inches of snow turn to water too fast, the water could pour unfiltered into the Potomac and Anacostia rivers, and eventually into the Chesapeake Bay. This week, environmental groups worried that such fast-moving water might carry road salt and other ice-melting chemicals, which can upset ecosystems and harm fish.
A fast melt might also be a good thing for a bad thing: the Potomac's snakehead fish.
The snow "is going to get into our waterways. It's either going to get in in a big dose, or it's going to trickle in slowly," said Bill Dennison, a vice president at the University of Maryland Center for Environmental Science. For fish and other creatures, Dennison said, if salt-filled water flows in too fast, "you don't have a chance. You don't have anywhere to hide, you don't have any opportunity to adjust. So that's the danger we're watching for."Climate change
A gradual melting is more likely, officials said: Temperatures are forecast to remain low over the next few days.
Scientists say that this year's snow has been driven by weather patterns that brought Pacific moisture and Arctic cold together. But they say that, in the future, climate change might make winter storms snowier, by increasing the amount of water taken up in clouds.
"That is not a contradiction, and it's not unexpected, " said Jane Lubchenco, the head of the National Oceanic and Atmospheric Administration.
Closer to ground level, scientists are still trying to measure the environmental impact of the storms.
Local wildlife, which evolved to deal with occasional blizzards, is likely to wait out the snow, rarely eating. Bob Beyer, of the Maryland Department of Natural Resources, said some animals might benefit as snow-laden trees break off or stoop over. The branches could provide shelter for deer or low-hanging food for rabbits.
Also, local officials said, it's possible that the snow will decrease air pollution as buried cars sit idle. "It's actually a net benefit, because fewer people are driving," said Dawn Stoltzfus, of the Maryland Department of the Environment, adding that tailpipe emissions provide one-third of her state's smog and greenhouse-gas emissions.
The catch, officials said, is that drivers might be inside their homes, playing Wii with the thermostat cranked up. In that case, increased emissions from power plants and furnaces might cancel out the savings.Salt and chemicals
In the water, the biggest threat posed by melting snow could be an influx of chemicals used to melt ice.
"Whatever we apply to our roadways, it's going to end up in our streams," said Sujay Kaushal, a professor at the University of Maryland Center for Environmental Science.
He has studied the effects of road salt on nearby creeks: In some cases, these creeks can become a quarter as salty as seawater.
Research has shown that baby salamanders and frogs don't survive as well in salty water. As for fish in these creeks, scientists said, the salt might not kill them outright, but it could leave them physically stressed and more susceptible to other ailments.
Because freshwater fish aren't like their saltwater counterparts, able to regulate their bodies' intake of salt, "the salt is sucking the water out of the cells, so it actually reduces the amount of water in your cells," Dennison said. "Even if you live in the water, you can be the equivalent of dehydrated."
Salinity levels have increased four times over in some creeks in Maryland during the past 25 years, Kaushal said.
Other road treatments are not much better: Sand can wash into nearby creeks and block sunlight needed by underwater plants. And fertilizer, used as a de-icer, can contribute to "dead zones" downstream in the Chesapeake.
Maryland's best advice for homeowners: Try to be "prudent," and use extra shoveling as a substitute for extra salt.
Then there are the snakeheads. First found in the Potomac in 2004, the Asian fish has spread across a 70-mile stretch of the river from Great Falls downstream to Upper Machodoc Creek, near the Route 301 bridge. And a little snow isn't going to stop them.
"They're pretty tough," said John Odenkirk, of the Virginia Department of Game and Inland Fisheries. "They'll just burrow down in the mud and ride it out." The worst-case scenario? Odenkirk said that if a fast melt produces a glut of water rushing down the Potomac, the snakeheads could simply ride to new homes even farther downstream.