Invasive water plant poised to overwhelm Potomac watershed.
'It springs to life each year in freshwater ponds and lakes as temperatures rise. By the middle of summer, the foliage is so thick and bushy at the surface that the water below is plunged into darkness, with hardly any oxygen seeping in from the air above.
Across Northern Virginia, the invasive aquatic plant has spread to dozens of locations, according to state and federal scientists. It looks a lot like Trapa natans, the water chestnut that has blanketed waterways on Marylands Upper Shore and the Northeast United States, but it isnt.
Its a different type of water chestnut: Trapa bispinosa. And Northern Virginia is the first place it has been found growing in the country.
Biologists want to keep it that way.
If eradication efforts dont ramp up soon, though, they warn that the species could spread beyond its current backwater haunts to the Potomac River and become a much bigger ecological headache. The 400-mile rivers currents could whisk T. bispinosa seeds just about anywhere, dampening hopes of containing the invasive plant, said Nancy Rybicki, a George Mason University professor and retired U.S. Geological Survey aquatic plant ecologist.'>>>
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