Point Pelee marsh restoration takes bite out of invasive species

A battle against relentless intruders is taking place at Point Pelee National Park.

Canada's second smallest national park is fighting to restore the health of its marsh, home to 19 species of at-risk and endangered native plants, through a meticulous process of marsh restoration.

“The marsh is very important for the region,” said resource conservation technician Emma Burbidge, during a virtual lunch and learn session Wednesday titled Open Marsh, Healthy Marsh.

“There's only about two per cent wetland cover left in Essex County, which means the park really represents one of the few remaining areas for all of the plants and animals that rely on wetlands to survive in the area.

“Overall, the marsh is just a very, very, very important habitat but unfortunately it is also under threat.”

Point Pelee's marsh covers about 1,000 hectares or approximately 2,200 football fields, and includes more than two-thirds of the park.

Burbidge said erosion and development have taken a toll on water quality, habitat diversity and wildlife and plants.

Once part of a larger wetland that encompassed 3,330 hectares of marsh that extended north to Hillman Marsh, drainage and dyking disconnected the two areas.

The marsh, the largest and most diverse habitat at Point Pelee, provides protection and a resting spot for migrating birds along with a home for snakes, turtles, fish, mammals, invertebrates, birds and plants.

But invasive cattail and European common reed, otherwise known as phragmites, are creating dense stands that eliminate open water, choke out native plants, decrease biodiversity and impede wildlife.

Burbidge said open water habitat within the marsh has been reduced by 10 per cent or 100 hectares since the 1950s.

“As we lose open water, we lose open water habitat,” she said. “And we also lose edge habitat, which is habitat that is between the open water and the vegetation.

“If you lose these habitats, you lose overall habitat diversity and in turn you lose … biodiversity.”

Staff have been focused since 2018 on conserving and restoring the health of the marsh, using a variety of tools including herbicide application to plants on land and hand-cutting phragmites under the water line to drown the plants.

This summer, two aquatic machines will be put into service — a vegetation cutter and a weed harvester — to open channels and ponds in the marsh.

Burbidge said the goal by 2022 is to create at least eight hectares or 8,000 square metres of open water and at least 3,000 metres of edge-water habitat by removing invasive cattail and phragmites. Some of the plant material that's removed is strategically placed for habitat mounds but much of it is burned.

“Right now, wildlife is in danger. Our biodiversity is in danger because we are losing very, very important open water and edge habitat,” she said. “So by creating these channels and ponds … and by managing these dense invasive phragmites, we will be benefiting native plants and animals.”

The new channels will also create new canoe and kayak routes for visitors to the park.

And it is hoped there will be improved wildlife viewing due to access and more plants and animals thriving in the new environment.

Visitors help the project by uploading sightings to inaturalists.org or ebird.org, sites that are monitored by staff.

To view the Open Marsh, Healthy Marsh presentation, in French or English, visit the Point Pelee Facebook page. For further information, visit www.pc.gc.ca/ en/pn-np/on/pelee/nature/conservation/marais-marsh.