A Parks Canada employee in hip waders helps remove phragmites at Beausoleil Island/Parks Canada

Canada’s smallest national park is gearing up for the second active season of a fight against an aggressive reed that has been called the country’s worst invasive plant.

Georgian Bay Islands National Park has dubbed the battle “Impede the Reed” and is removing invasive phragmites because they’re destroying shorelines and habitat for key species including musk (stinkpot) and map turtles.

“We’re not going to just manage the species here, we’re going to eradicate the species,” promises the park’s resource conservation manager Andrew Promaine. “This is important for turtles to repopulate themselves and for the shoreline to have integrity.”

Georgian Bay Islands protects 63-odd Ontario islands within the world’s largest freshwater archipelago. It straddles two ecoregions as it lies on the southern edge of the Canadian Shield where windswept white pines and Precambrian granite shores transition to a mixed coniferous and hardwood forest dominated by sugar maples and beech trees. The main island, Beausoleil, is eight kilometres (five miles) long and shows Canadian Shield at its north end and Great Lakes-St. St. Lawrence Forest Region at its south end.

The boat-access nature preserve stretches 50 kilometres (31 miles) along eastern Georgian Bay. and protects 25 species at risk. With its lichen-flecked rock outcrops, marshes, bogs, ponds, swamps, wet forests and marshy shorelines, it’s home to 33 species of reptiles and amphibians — the most of any Canadian national park — including the threatened Eastern Massasauga Rattlesnake, the only snake in Ontario whose venom is poisonous.

Phragmites australis subspecies australis (the European common reed) is an invasive perennial grass with tan/beige stems, blue-green leaves and large, dense seedheads that has caused severe damage to wetlands and beaches in Ontario for several decades, according to the provincial government. It’s unclear how phragmites (pronounced “frag-my-teez”) got to North America from its native home in Eurasia but the ornamental plant was identified in 2005 as the nation’s “worst” invasive plant species by Agriculture and Agri-food Canada researchers. It doesn’t have any native predators or competitors.

Invasive phragmites stands threaten shorelines at Georgian Bay Islands National Park/Parks Canada

Georgian Bay Islands has experiences a 250 per cent growth of phragmites since 2010, resulting in a declining trend in the ecological integrity of the park, according to the Canadian Impact Assessment Registry. It’s estimated that 20 per cent of Beausoleil Island’s shoreline has been impacted, “which is worrisome for GBINP’s wetlands — critical habitat for many species at risk.”

Phragmites grows up to five-metres (16-feet) high in thick, dense stands on the shoreline, as well as in wetlands and ditches, out-competing other species and acting as a barrier to wildlife. Its roots release toxins into the soil to kill surrounding plants or reduce their growth.

Georgian Bay Islands has worked with Georgian Bay Forever and the Severn Sound Environmental Association on a co-ordinated response. The park applied for funding from Parks Canada’s Conservation and Restoration program two years ago, and spent 2019 doing background research, project planning and identifying priority areas for removal.

Despite Covid-19, 2020 was the first field season and the Impede the Reed program is expected to last four or five years. Outside of the park, Georgian Bay forever mapped 711 stands (sites) in 2020, and cut 170 of them thanks to 475 hours of work by 84 volunteers.

Georgian Bay Islands used gas-powered trimmers, cane cutters and spade shovels to cut phragmites underwater using the “cut and drown method” for populations in standing water and the spading technique for terrestrial plants, according to a winter 2021 newsletter. Open-fronted barges took the biomass to shore and a floating boom was installed to prevent any spread away from the site.

The next step was to “smother” the cut phragmites with help from a special tractor that runs over and condenses the pile, and then leave the compost piles to dry out at a control site about 27 metres (90 feet) from shore. The piles were kept above the water line and flipped throughout the season.

The cut phragmites are hauled away from shore and kept in crushed piles/Parks Canada

“Even one stalk left floating can establish itself elsewhere,” says Promaine. “It’s a lot of labour. It’s hard work to remove it.”

The results show that 1.3 hectares (3.2 acres) of phragmites was removed in 2020 and 10.8 hectares (26.6 acres) remain to be removed this year. The park is testing other removal and disposal methods, including amphibious mechanical harvesters and prescribed burning of biomass piles.

After the 2020 removal, Promaine said parks staff saw about half a dozen musk (stinkpot) and map turtles in the area — not a huge number, but “half a dozen more than we saw before.” It’s nurturing the island’s turtles by erecting two nest mounds to create a desirable nesting habitat from sand and small gravel with a sloped side towards the water, and turtle nest protector boxes to protect natural nests from raccoons, foxes and gulls.

“I can’t say enough about turtles,” enthuses Promaine. “They live a long time and one thing that fascinates me is that they’re not necessarily from the here and now.” The turtle species in the park only grow to 30 centimetres (one foot), but they do live to 80 to 100 years and are an indicator that the ecosystem is doing all right in the face of ongoing habitat loss. “You can imagine that the turtles we see today were born 100 years ago — that’s like Galapagos-level turtles,” says Promaine. “The loss of a species would be like pulling out the spoke of a wheel. The more spokes that come out of that wheel, the more we’re looking at collapse.”

Superintendent Camille Girard-Ruel says the park forms a core protected area within the Georgian Bay Biosphere Reserve, and “everything we do has to be connected because we are so small and dispersed.”

As Promaine adds: “Just because we’re not huge, it doesn’t mean we can’t think big.” A new Impede the Reed website should be unveiled within a month and will include the newsletters the park already puts out.

When campers arrive by boat at Georgian Bay Islands National Park, Parks Canada loans them luggage carts/Parks Canada

Georgian Bay Islands was formed in 1929 as local residents, worried that wealthy tourists were buying up area islands, petitioned the federal government to set aside Beausoleil Island as a national park. The park’s total area is now about 14 square kilometres (5.5 square miles).

Beausoleil Island is also a national historic site and protects a significant cultural landscape with 13 archeological sites that show human activity and settlement that dates back 7,000 years and suggest the island was likely used as a summer camp by early hunting and gathering cultures.

The park’s season runs May 21 to October 11, and online reservations should open in April. Beausoleil has 103 campsites, 10 rustic cabins and five oTENTiks.

The park usually shuttles about 5,000 annual visitors to Beausoleil on a 12-passenger boat called the DayTripper, but it didn’t operate in 2020 due to Covid-19. Visitors could still visit via private vessels and water taxis.