One of the first things people notice about the brilliant new park at the mouth of Toronto's Don River - once so polluted it caught fire, twice - is the wildlife. Look, it's a rabbit. Hey, is that a bald eagle? Oh, there's a monarch butterfly.
Biidaasige Park opened last month on the east side of Toronto Harbour. The name is pronounced "bee-daw-si-geh," a phrase in the Anishinaabemowin language that means "sunlight shining toward us." It flanks a kilometre-long extension of the Don, part of a $1.35-billion, two-decade effort to protect the area from flooding. Engineers replaced the cement-lined old river mouth with a winding channel and a spillway to redirect floodwaters.
Since the park took shape, creatures great and small have been rushing in like Black Friday door-crashers. Swallows, terns and red-winged blackbirds fly above the sparkling river. Bass, pike and walleye swim up and down it. Butterflies come to feed on the flowers and dragonflies to snap up the bugs.
At the risk of anthropomorphizing, they all seem delighted to have discovered this oasis in the heart of the city. Even local naturalists are surprised how quickly the fauna have made themselves at home. After all, the new river channel runs through the Port Lands, an old industrial district whose soil was heavily contaminated. Traffic streams along the nearby Gardiner Expressway. The soaring towers of the city's downtown are only a few minutes away.
The park is an example of an encouraging trend in this time of environmental anxiety. Around the world, modern cities are restoring ruined ecosystems.
Paris cleaned up the Seine, which now teems with fish. Tourists and locals line up to take dips in the once filthy river. Seoul tore down an elevated expressway and brought back a dried-up stream underneath it. Birds, insects and plants proliferated.
London is "rewilding" some of its ancient royal parks, leaving fields unmowed so wildflowers can come back. Beavers, absent from the English landscape for centuries, have been reintroduced and taken up residence in the woods of West London.
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At High Park in Toronto's west end, managers use controlled burns to preserve a fragment of rare black oak savannah, which depends on periodic fires to thrive. More than 40 species of butterflies now live there. At Tommy Thompson Park on the other side of the city, a whole new ecosystem made up of natural and invasive species has sprung up spontaneously on a long, artificial promontory made of excavation waste. Conservation authorities have helped by creating new wetlands on the landform.
These are small measures of atonement for the destructive ways of the past. We have done - and continue to do - incalculable damage to the planet that sustains us. The Port Lands were once the site of what is thought to be the largest marsh on the north shore of Lake Ontario. Effluent from distilleries and tanneries on the Don turned it into a cesspool. City fathers, worried about disease, drained it and filled it in.
Renaturalizing the mouth of the river is an attempt to bring back at least a part of what used to be. Park planners spent years selecting the right plants to introduce and the right kind of soils to support them. They brought in cattails and bulrushes, willows and cottonwoods, buttonbush and wild bergamot, sage and sweetgrass. Visitors can be seen snapping pictures of all the flowers and looking them up on their identification apps.
Making sure that this manufactured slice of nature thrives is a challenge. Park workers are already battling invasive species like phragmites, a tall reed with a bushy head that crowds out native plants. They have installed special "carp gates" to keep the big fish from getting in and turning the marsh waters turbid.
But much of the flora and fauna there will do fine on their own. Mother Nature is a tough old bird. The success of these restoration efforts shows how resilient our embattled environment can be. Given a chance, and a helping hand, it will come roaring back.
While they were digging up masses of earth for the Port Lands project, workers found some old soil from the original marsh buried there. They noticed century-old seeds in it had started to germinate. They moved the soil to the park. New wetland plants grew from it - reborn remnants of what humans had destroyed all those years ago.