Cootes Paradise Marsh Recovery: 2025 Milestone

By Tys Theijsmeijer, Senior Director of Ecosystem Stewardship Programs and Policy

Cootes Paradise Marsh continues its remarkable ecological recovery, taking another major leap forward this year with the return of extensive clear water conditions. It’s an exciting and hopeful milestone in the long journey back to environmental health.

If you’ve never seen the bottom of the marsh during the summer months, now is the time—visibility is the best it’s been in decades. In many areas, dense aquatic vegetation has taken hold, so it may take a bit of effort to peer through, but that’s a good thing. This marks the third consecutive year of large-scale regeneration of aquatic plant communities.

Unlike the recent period of set back by the impacts of the Chedoke Creek sewer spill, much of the marsh is once again home to thriving aquatic vegetation rather than murky algae blooms. For the first time in generations, it actually looks and functions like a wetland. The water is clearer, and the ecosystem is responding. The current plant life is dominated by just a few pondweed species, characteristic of early-stage ecological succession. Encouragingly, a wider variety of native aquatic species is beginning to re-establish itself. Target species like water lilies, wild rice, and bur-reed are becoming more abundant each year, signaling real progress towards a diverse habitat.

This success is the result of decades of restoration work, including control of the once-destructive Common Carp population and the elimination of inflowing sewage spills. These large invasive fish, which uprooted plants and clouded the water for decades, are now largely under control. It’s the most marsh-like Cootes Paradise has looked since the 1940s—when studies first documented its decline and reminiscent of old photos and paintings from a century previous.

This year’s dry weather has also played a supporting role. Reduced rainfall means fewer sewer overflows from upstream systems, allowing the marsh a chance to heal. Despite the dry conditions, overall water levels remain average.

The clearest signs of recovery are visible away from the direct influence of Chedoke Creek. Visitors to the waterfront trail near Chedoke Creek’s outlet may still find conditions underwhelming. But just a short walk west, to west side of Princess Point reveals a different picture: clean water, thriving vegetation, and a glimpse of what a restored Cootes Paradise can truly be.

Still, the work isn’t over. Long-term sustainability requires continued efforts to improve inflowing water quality, leading to increased dissolved oxygen levels, and permanently reduced nutrient pollution. This is what is needed to end the dominance of invasive fish species like Common Carp and Goldfish, and eventually eliminating the need for the Cootes Paradise Fishway and habitat sustainability.