"But when you don't take action rapidly ... not only does it result in a much longer potential recovery time, but the uncertainty as to whether recovery will happen at all increases exponentially," said Jeff Hutchings, a professor of biology at Dalhousie University and one of the authors of the study.

Hutchings said that may explain why cod hasn't bounced back more than 20 years after Ottawa declared a moratorium on the commercial cod fishery, a once thriving Atlantic Canadian industry.

"Here we are two decades after enormous depletion of cod stocks ... and people are still wondering about the prospects of recovery," said Hutchings