New DFO northern cod assessment model shows stock out of critical zone

Fisheries and Oceans Canada has implemented a new assessment model for the 2J3KL northern cod stock, which reveals the stock has likely been out of the critical zone since 2016.

The new model assesses the long-term productivity using tagging and landing data from the last 70 years. The old model used data beginning in 1983, but research scientist Paul Regular says the model has been expanded to pull on data from as far back as 1954.

"A bunch of changes were accepted, and they helped us improve the understanding of the past trends in the stock, and also the relationship between adult cod and young cod," Regular said Wednesday.

"Overall the trends look similar, but now we have a longer-term perspective on the stock. And getting that bigger picture … is quite important for capturing, getting a better sense of how productivity has changed through time as well."

One of the biggest changes the new model brings is to the limit reference point, the line a stock must reach to go from the critical zone to the cautious zone.

The old reference point meant there had to be 800,000 metric tonnes of fish to hit the cautious zone. That number has now been lowered to 315,000 metric tonnes.

So, in essence, the number of cod in the water hasn't changed — but how the stock is assessed has, thanks to three decades of extra data.

"The new information provided us a better and more precise understanding of how productivity has changed through time, and helped us pinpoint better the point below which we fear that productivity of the stock is impaired," Regular said.

"It helps us demarcate that critical and cautious zone a little bit differently, but perhaps a little bit more precisely. This was quite the important advancement."

The northern cod stock in Newfoundland and Labrador had been in the critical zone since 1991, a year before a moratorium was placed on the fishery.

The new assessment model also includes more new tools, like the integration of capelin abundance, which can be used to anticipate cod productivity and mortality rates.

It will be used in a new assessment in March 2024. It's a stark contrast to a 2021 assessment which indicated there was a 99 per cent chance the stock was in the critical zone, Regular said.

Using the new model shows there is a 71 per cent chance the stock is in the cautious zone, he added.

Fish, Food and Allied Workers union president Greg Pretty said in a news release the work done to create the new model is a positive step forward for the industry, and is pleased to see surveys going ahead as planned.