Almost two decades after the federal government announced a moratorium on cod fishing in Canada, a new study shows the once-dwindling Atlantic cod stock is on the road to recovery.
Researchers from Queen’s University and the Bedford Institute of Oceanography in Nova Scotia said that cod, as well as other groundfish populations, are growing in numbers off the coast of Nova Scotia.
“This early-stage recovery represents a long ecological transition for an ecosystem that was pushed out of balance and that is gradually moving back into balance,” said William Leggett, Queen’s biology professor and expert in the dynamics of large marine ecosystems, in a university press release.
The Atlantic cod fishery collapsed in the ’90s and an all-out moratorium was announced in 2003. The move was devastating for East Coast fishing industries that depended on the fish, which were once so plentiful, fishermen would joke that you could step out of your boat and walk on their backs.
Shifts in the ecosystem prevented the stocks from replenishing before now, according to the study published Wednesday in the journal Nature.
When cod and groundfish were plentiful, they fed off smaller “forage fish.” When overfishing depleted the bigger fish’s populations, the forage fish turned to bigger fish’s spawn for food, including baby cod.
Over the years, the forage fish population swelled to almost 900 times its original numbers, preventing groundfish stocks from recovering.
But now, the population has grown too big and out-stripped its food sources. That means big fish like cod and haddock can start to make a recovery.
Cod are now at 34% of the level they were in the ’70s and ’80s when the fishery flourished, and haddock have actually surpassed previous records.
This “bodes well” for other collapsed fisheries north of Nova Scotia, such as off the coast of Newfoundland, the study notes.
A 2010 report by the the Northwest Atlantic Fisheries Organization showed that the cod numbers in Newfoundland’s Grand Banks grew 69% since 2007, but remained at just 10% of its ’60s population.
But while groundfish numbers are swelling, the study paints a cautiously optimistic future for the cod.
“It’s difficult to say if this switch may have any long-term implications,” said Jonathan Fisher, a postdoctoral fellow at Queen’s University’s Department of Biology. “This system may return to its historical character, but there’s also the possibility that it won’t and that another species will dominate. Only time will tell.”