There is an alien invasion happening in Southern Georgian Bay. Aggressive green organisms, which arrived here from afar and colonized our region along with other parts of Ontario in the last century, are spreading their seeds and growing their numbers, wreaking havoc on our communities and destroying all other life in their path. The continued efforts of a few brave souls to combat the aliens' relentless advance, along with education to identify the invaders and keep them from running amok, are, if not eradicating the green monsters, at least keeping them contained. But the battle goes on.
This alien invasion is a close encounter of the herbivorous kind, posing no direct threat to human life but menacing our natural environment and all of its inhabitants, which ultimately threatens our way of life. The alien is a grassy plant species named phragmites australis (known colloquially as invasive phragmites, European common reed, or more simply, phrag), which originated in Eurasia. Like so many invasive species, it is difficult to say exactly how it arrived in Southern Georgian Bay, but it appears determined to stay.
These aggressive plants, which grow up to 18 feet (5 metres) high in stands of up to 200 stems per square metre, are spreading like a plague in our wetlands and on our shorelines, out-competing native species for water and nutrients and releasing toxins from their roots to harm and kill surrounding vegetation. "Where you see a stand of invasive phragmites, you don't see much else growing," says David Sweetnam, executive director of Georgian Bay Forever, a charitable organization whose mission is to protect, enhance and restore the Georgian Bay ecosystem.
Sweetnam describes stands of the invasive plants as dense and tall, virtually impenetrable to humans, and problematic for wildlife such as turtles, raccoons and even deer, which can become disoriented in their midst and die of exhaustion trying to escape. "Invasive phragmites has no natural plant-eating predators to keep it at bay, and there are no native plants that can live with it," explains Sweetnam. "By contrast, a similar-looking species of native phragmites shares its territory, allowing other plants to grow nearby."
According to Sweetnam, invasive phragmites (pronounced frag-MITE-ees) arrived in North America in the early 1900s, likely transported from Eurasia in the ballasts of ships. Slowly spreading to the east coast and into the Great Lakes, the species has been gaining a foothold in Southern Georgian Bay for the past 15 years.
"People started to become aware of it here in the last decade or so," says Sweetnam. "Provincial parks and groups like Georgian Bay Forever took action on the issue, physically removing the species from wetlands and searching for new infestations." Among its projects, Georgian Bay Forever has been involved in combatting invasive phragmites infestations in the Lighthouse Point, Dockside and Rupert's Landing communities of Collingwood, and conducts public information sessions all along the Georgian Bay coastline where phragmites is taking over.
While some areas are gaining headway in the battle against the alien, potential solutions to completely eradicate these monsters pose a number of challenges. Burning the plants can actually increase shoot densities and the below-ground biomass of phragmites. History has shown that biological warfare with an introduced plant or insect can result in a whole new unchecked invasion. (Case in point: the Asian ladybug, which was brought to North America from Japan in 1988 to combat aphids and other agricultural pests, but with few natural enemies, the beetles have become a major pest themselves). Chemical herbicides are out due to the risk of contaminating our waters, but a number of biochemical control mechanisms are currently being researched.