In a country filled with lakes and with oceans on three sides, Canadians know fish as a source of food, jobs and pleasure. They grow up catching, eating and enjoying the bounties of the deep.

But as everyone knows now, Canada is in danger of fishing many species into extinction. The country's fish have become, in many instances, a precious and rare commodity.

Are we headed toward the end of fish?

In his new book The Ocean of Life — The Fate of Man and the Sea, Callum Roberts catalogues the impact humans have had on ocean ecosystems, from climate change to noise pollution to plastic contamination to overfishing.

But Roberts, a marine conservation biologist at the University of York in England, is still an optimist.

He tells Quirks & Quarks host Bob McDonald that we can help oceans recover and rebuild our fisheries, paradoxically by fishing less to catch more.

The complete interview is available here.