A new satellite-aided model shows that phragmites — invasive, feather-topped reeds twice the height of a basketball net — are forecast to spread exponentially across the Great Lakes.
And officials say they’re barely able to manage existing stands of it, much less control its spread.
“When I go into coastal wetlands and they’re infested with phragmites, it’s absolutely astonishing. We’re losing our wetlands because of them,” said Janice Gilbert, a wetland ecologist and a founder of the Ontario Phragmites Working Group.
An analysis using NASA satellite mapping shows vast swaths of urban and rural land overtaken by phragmites by 2020.
Mississauga, Collingwood and St. Catharines are among Ontario municipalities where small or moderate populations of the plant are likely to expand, researcher Sean McCartney told a group of mayors of the Great Lakes and St. Lawrence Cities Initiative, which commissioned the research.
In urban areas, earth-moving equipment often spreads the seeds that then propagate across entire neighbourhoods. “Wherever humans interact with nature, we are seeing it’s leading to the spread of phragmites,” McCartney said.
Municipalities are spending millions, but they’re barely able to manage existing populations.
They’re expensive to attack, said Nancy Vidler, but municipalities and residents have to weigh that against the higher cost of doing nothing. She is part of a Lambton Shores community group that has been working with residents and municipal officials to get the plants under control in Port Franks wetlands, ditches and roadsides. The cost of that project has been about $200,000; a similar project near Kettle Point has cost $300,000.
By contrast, they detected 12 small cells near Grand Bend and treated them at a cost of $3,000. “Early detection and rapid response . . . are so important,” Vidler said.
Tay Township Mayor Scott Warnock said the invasive plant is “becoming one of the most pressing issues for the communities in the Great Lakes basin.”
In Long Point, for example, they were detected 20 years ago and now make up 40 per cent of the wetland.
Gilbert has been on the forefront of research and eradication in Ontario and said phragmites can survive in almost any conditions and out-battle any native plants.
“I think we’re at a crossroads,” she told the mayors. Officials can either “keep bumping along” from site to site, or take an immediate, strategic approach.
They’re rife along lakeshores, but another key area to tackle is along public roadsides and ditches.
Gilbert noted later London is one of the few municipalities that have staff environmentalists to eradicate and manage problem sites.
But Ontarians have fewer tools than in the U.S., where herbicide application is less restrictive. Even if regulations are relaxed, some chemical treatment can’t be used near waterways.
On the American side of the lakes, some management is taking place but it is still far from under control, said Heather Braun, a manager with the Great Lakes Commission and part of the Great Lakes Phragmites Collaborative.
For the most part, landowners and municipalities still work independently of each other and “that’s a recipe for disaster,” Braun said.
Even where vast acreages of phragmites are herbicided, flooded, removed mechanically and burned, management is usually needs to be repeated after only a couple of years.
“We’re essentially treating the symptom rather than the cause,” Braun said. “We need . . . to get control over this issue.”
Some townships have called on the province to name phragmites a noxious weed, which would enable authorities to go onto private property to deal with it if necessary.
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Phragmites (pronounced frag-MY-tees)
Invasive species with origins in Europe
Suck up nutrients from their environment and out-compete native plants such as cattails and willows; they result in loss of habitat for other plants and animal/aquatic life and further jeopardize species at risk
Plug agriculture drainage ditches and cause flooding
Can have a density of 200 plants per square metre; their dead stalks resist decay, filling in open ponds and creating dead zones unusable for wildlife
Once their seeds colonize an area, they spread quickly with seeds and rhizomes.
Also spread with earth-moving equipment along roadways, in new subdivisions, and across farm fields.