Downward spiral for Atlantic cod continues in Gulf of St. Lawrence

The latest assessment of Atlantic cod fish stocks in the Gulf of St. Lawrence continues to paint a bleak picture for the future of the species.

Fisheries and Oceans Canada issued a warning five years ago saying extinction of the species in the gulf was not just possible, but probable.

The first assessment since then has been released.

“We are not seeing any recovery of the spawning stock biomass of that stock. It is still experiencing really high levels of natural mortality, especially at the adult stage of life,” said federal Fisheries and Oceans biologist Daniel Ricard.

“It’s a very dire situation.”

Between 60 and 70 per cent of cod in the southern gulf do not survive beyond age five and are likely being eaten by the huge herds of grey seals in the region, Ricard said.

“The most likely cause of the increase in natural mortality is an increased predation by grey seals.” 

New fish die off

Cod were able to withstand large numbers of seals in the past, but that was before overfishing caused the cod population to collapse several decades ago.

Seals are now preventing a recovery, even though recent surveys detected increased numbers of young cod.

“We are seeing influxes of new fish that essentially die off before they reach their teenage years or their adult years. The cod population is at a low level and seal predation is at a high level and they’re unable to get out of that situation,” Ricard said.

That bump has slowed the predicted rate of decline, but the decline continues.

Since the last assessment in 2019, the spawning population estimate has fallen from 13,900 tonnes — then a record low — to 12,000 tonnes in 2023.

That represents a 97 per cent reduction from the 320,000-tonne peak in the 1950s.

Scientists use spawning stock biomass as a measure of the health of a species. It’s an estimate of the total weight of the fish capable of reproduction.

Commercial extinction looms

There has been a moratorium of directed cod fishing in the southern Gulf of St. Lawrence since 2009.

Even with no fishing, long-term projections indicate cod in this area are on their way to commercial extinction — that’s when there are so few it’s not worth trying to catch them — within 50 years.

Commercial extinction occurs when the spawning population dips below 1,000 tonnes.

At that level, cod would not entirely disappear in the gulf but would be vulnerable to harsh environmental levels.

Pulling out of this spiral would require phenomenal recruitment — young fish surviving to reproduce — to overwhelm the system or seals would have to switch to another prey, Ricard said.

Fisheries and Oceans is not predicting either scenario. “It’s not a rosy outlook for this stock. The longer-term trajectory is unchanged.”

The no-win scenarios to rebuild cod population

Atlantic cod are paying the price for past government management of the fishery when quotas were too high.

It leaves DFO few options to try to rebuild the stock.

One is to reduce the bycatch allowed in other fisheries that accidentally capture cod — namely those harvesting redfish, halibut and turbot.

Right now Fisheries and Oceans allows 300 tonnes of cod to be taken as bycatch in the southern Gulf of St. Lawrence. Reducing bycatch will hurt those fisheries with relatively small benefit to cod, but it is being considered.

The other option is to reduce the grey seal population, which would have a far greater impact on survivability of Atlantic cod, but is politically unpalatable.

“One lever is clearly there. The other one is much more contentious,” said Ricard.