ASSATEAGUE — The never-ending war against invasive phragmites on Assateague Island got quite a few more foot soldiers on the front lines last week when teams of National Park Service workers from other regions all over the country arrived on the barrier island to join the fray.
Assateague Island National Seashore officials last week began anew the effort to eradicate, or at least contain, the spread of noxious phragmites. The prolific, non-native and highly invasive plants take over salt marshes and other coastal areas, stunting the growth of indigenous plant life struggling to co-exist with them. Left unchecked, phragmites would eventually take over the marshy areas and upset the natural order on the barrier island.
“It’s an exotic, non-native plant, a weed really, and it is aggressive and invasive,” said AINS Science Communicator Kelly Taylor this week. “It out-competes native species and alters wildlife habitat. Animals that have feeding patterns often have to go elsewhere for food. It’s really a big mess.”
For years, AINS officials have waged a constant battle against phragmites with controlled burns and aggressive aerial spraying and ground spraying of a herbicide called Habitat, which kills invasive plants with little or no collateral damage to native vegetation or wildlife. While the efforts have been effective to some degree, it’s often a constant battle just to maintain the status quo.
“They never quite go away,” said Taylor. “Usually, it takes a combination of treatments just to bring it under control. Just when you think you’ve eradicated in one area, it pops up in another area.”
Taylor said roughly 1,700 acres on Assateague are impacted by phragmites. With just one full-time plant management employee sometimes supplemented with college interns or volunteers, the most foot soldiers AINS can send into battle against the invasive phragmites is typically around four.
Last week, however, at the onset of another attempt at eradication or at least containment, Assateague got additional help from five National Park Service Exotic Plant Management Teams. The teams came from five different regions including the National Capital Region, the Northeast Region, the Southeast Region and the Southeast Coast Region. Together with the four regular Assateague workers, the five teams multiplied the usual ranks six times.
“We had a boatload of people,” she said. “They came from several different regions and they are all Park Service people. Many of them wore backpack sprayers and could get into remote areas away from roads. We also had a large truck with a sprayer to get to areas too thick for people to get into.”
Taylor said as a result, the expanded effort was able to reach far more stands of noxious phragmites that could ever hope to be accomplished in a single season.
“We have one full-time employee dedicated to plant management and we supplement that during the summer with college interns and volunteers,” she said. “The most we would have at one time is four, but we had 25 people with this latest effort. With our four-person team, the most we could hope to do in a season is about 50 acres. With 25, we had several spots that we identified as problem areas that we wanted to spray and we got to all of them.”
Last week’s effort was one of the most concentrated and far-reaching in recent memory. In 2009, highly trained Park Service workers undertook a massive controlled, or prescribed, burn of the highly invasive phragmites. The effort was successful to some degree, especially when followed by an aggressive Habitat spraying campaign, but the controlled burn only eliminated the noxious weeds on the surface.
“One of things we learned from the controlled burn is that 80 percent of its biomass is stored below the surface,” she said. “We can burn the top, but there are plenty of opportunities for sending up new growth.”
Similar to most weeds, phragmites regenerate rapidly and must be completely removed or destroyed to prevent them from spreading further. Infested areas such as Assateague frequently experience hydrologic changes and often no longer serve as suitable habitats for native fish and wildlife species. There is also an aesthetic element to the eradication efforts as healthy phragmites grow up to 12 feet tall and can block scenic vistas and views.
It remains uncertain just how successful last week’s latest effort to eradicate or contain phragmites on Assateague was, but it certainly wasn’t for a lack of effort. Twenty-five foot soldiers armed with backpack sprayers and a large truck, or tank, hitting areas the infantry couldn’t reach represented the largest assault in recent memory.
“We should be able to tell in a few weeks,” she said. “We’ll go back to those areas we sprayed and check them out, but we’ll probably have to go back and hit them again.”