Soil secrets Ancient plants and seeds come back to life

A wetland restoration has lead to astonishing discoveries as scientists have been able to resurrect fleas and plankton

- By Leyland Cecco TORONTO

When Shelby Riskin was handed disc-shaped samples of century-old soil from 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.

But when she and a graduate student peered through a microscope, they watched in astonishment as a brown wormlike creature greedily munched through green clumps of algae as if more than 130 years hadn't passed since its last meal.

Equally oblivious, a host of life - water fleas, worms, plankton-danced and spun 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 due to be published soon 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 re-naturalise a major river and the surrounding lands was advertised as one of the "largest waterfront revitalisation projects" in the world. As the project nears completion, the discoveries have underscored the resilience of ecosystems in the face of human-led destruction.

The samples that came to Riskin had themselves 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.

When one of the bulldozers was halted by thick green shoots, the machine operator soon realised that the sedges and cattails looked nothing like the other weeds at the site.