Elephant seals, sea lions and even a peregrine falcon have reappeared on the West Coast thanks to a massive rewilding effort that has made Victoria and Esquimalt Harbours cleaner than at any time in the past 50 years.

The $135-million Rock Bay Phase 3 cleanup project has just concluded in the Victoria Upper Harbour. It was one of the last major steps in what will be a four-decades-long, $500-million effort to remove toxic sediment left by an old power plant.

"It's a huge, untold success story; something that needs to be celebrated," said Brian Keating, wildlife columnist for CBC's The Homestretch and Radio Active.

Busy aquatic airstrip sees return of wildlife

Orcas, elephant seals, beavers, Olympia oysters, marbled murrelet, rhinoceros auklets, herring, bay pipefish and coho salmon all have been seen in the area.

It's especially remarkable considering the Victoria Harbour is the busiest floatplane airfield in Canada, Keating said.

This resurgence in wildlife has brought relevance back to the Victoria Harbour Migratory Bird Sanctuary, said Keating.

That sanctuary was one of three established in the 1920s to protect the Brant goose and other waterfowl from market hunting.

Back in the 1910s, wildlife experts feared that the Brant goose would be driven to extinction by market hunters, prompting officials in Canada and the U.S. to sign the Migratory Birds Convention Act. (Getty Images)

In 1916, the Migratory Birds Convention Act was signed between the United States and Canada to protect these animals from illegal trafficking and commercialization after the passenger pigeon had been driven to extinction by market hunters just two years prior, Keating said.

"The passenger pigeon was one of the most abundant birds on the planet, and yet we wiped it out completely. It looked like the same thing was going to happen to the Brant goose."

The conservation initiative has so far managed to prevent that outcome.

Jacques Sirois, chairman of the Friends of Victoria Harbour Migratory Bird Sanctuary, hopes to see a U.N. Biosphere Reserve established in the area.

"He thinks that would make the 100 year celebration since the migratory treaty absolutely perfect," Keating said.