Back to life Scientists stunned by resilience of ecosystems long buried under Toronto

When Shelby Riskin was handed samples of soil buried for a century under Toronto's waterfront, the ecosystem ecologist was hopeful she might find trace evidence of plants - cattails, bulrushes, water lilies and irises - that had once populated a long-destroyed wetland.

- Leyland Cecco

But when she peered through a microscope, she watched in astonishment as a brown, wormlike creature greedily munched through green clumps of algae. A host of life - water fleas, worms, plankton - danced around it.

“We’ve been able to resurrect some of the ancient life that shows what this wetland was like prior to urbanisation,” said Riskin, a soil expert at the University of Toronto who was called in to analyse the samples. “It’s hard not to get really excited about this.”

Riskin’s work and separate research from a paleoecologist have contributed towards two peer-reviewed studies to be published on the team’s findings.

For the researchers, the discoveries do more than just serve as a novel time capsule. Toronto’s multibillion-dollar effort to renaturalise a major river and the surrounding lands was advertised as one of the largest waterfront revitalisation projects in the world. The discoveries have underscored the resilience of ecosystems in the face of human-led destruction.

The samples that came to Riskin had been the source of disbelief three years before, when heavy machinery was excavating vast amounts of dirt and debris from Toronto’s waterfront in an effort to reroute the Don River.