BETHEL, Vt. — Last year’s hurricanes and flooding not only engulfed homes and carried away roads and bridges, they dispersed aggressive invasive species as well.
In Vermont, floodwaters from Tropical Storm Irene and work afterward to dredge rivers and remove debris spread fragments of Japanese knotweed, a plant that threatens to take over floodplains wiped clean by the August storm.
The overflowing Missouri and Mississippi rivers last year launched Asian carp into lakes and oxbows where the fish had not been seen before, from Iowa to the Iowa Great Lakes. Flooding along the Missouri River also increased the population of purple loosestrife, a plant that suppresses native plants and alters wetlands.
“It’s quite an extensive problem around the country, and it’s spreading,” said Linda Nelson, an aquatic-invasive-species expert with the U.S. Army Corps of Engineers.
The agency’s budget for controlling invasive aquatic plants has grown from $124 million in 2008 to $135 million for fiscal 2012.
