A retired biologist says the survival of Lake Superior caribou is hanging in the balance due to the impact wolves have had on the herd.

Gord Eason, who had a long career with the Ontario Ministry of Natural Resources and Forestry, in Wawa, Ont., said wolves got to Michipicoten Island via an ice shelf five years ago.

So began the rapid decline of the herd.

"During the cold winter of 2014, three or four wolves got across to the island on the ice and they started to reproduce and built their numbers up to close to 20," said Eason."And there were around 900 caribou on Michipicoten Island according to our projections, and (the wolves) did them in in a matter of about four years. By last winter they were gone."

This past winter most of the wolves were trapped from Michipicoten Island and moved to Isle. Royale, in Michigan. The animals have been placed there to keep a booming moose herd in check.

Eason, who is working with a small group of people to help conserve and preserve Lake Superior caribou, said wolves also all but wiped out the animals on the Slate Islands.

Last winter, the Slate islands famous caribou herd was reduced to two male caribou.

"It's called functional extirpation, when your population can't recover because you are down to just one sex," he said

Eason said the OMNRF has been working to help the caribou and moved some females and another male to the Slates to get that population going.

Lake Superior caribou numbers have dropped to less than 50 animals due to predation by wolves. (photo: Brian Mclaren)

He said this past winter the last six caribou from Michipicoten Island were moved to remote Caribou Island, on Lake Superior.