Swordfish are moving north into Canadian waters

Open in full screen mode

There were 1,900 tonnes of swordfish caught in Canada last year.

Radio- Canada

Speech synthesis, based on artificial intelligence, makes it possible to generate spoken text from text written.

Canadian scientists and fishermen are tracking the movement of swordfish north into Newfoundland waters, where the prized fish is being caught in large numbers.

It is unknown whether these data are the consequence of ocean warming or a cyclical and temporary event.

It's still unclear whether this will be the new normal due to climate change or whether biomass will eventually decline, says Kyle Gillespie, a biologist with the Department of Fisheries and Oceans Canada (DFO).

One ​​thousand nine hundred tonnes of swordfish were caught in Canada last year. A third were caught off Newfoundland, where Nova Scotia longliners dragged baited hooks for much of the summer.

Kyle Gillespie says this is a rapid change from the previous decade, when the entire Canadian catch was concentrated along the Scotian Shelf and Georges Bank off the coast. southern Nova Scotia.

What is particularly interesting when we analyze the data from Newfoundland is that per 1000 hooks , we have a lot more fish, and they are bigger, he says.

This distribution shift has coincided with a collapse in spear fishing landings off southern Nova Scotia over the past three years.

LoadingA King Charles III's planned visit to Canada postponed

A planned visit by King Charles III to Canada is postponed

ELSE ON NEWS: A planned visit by King Charles III to Canada is postponed< p class="StyledBodyHtmlParagraph-sc-48221190-4 hnvfyV">Between 2011 and 2020, harpoon catches averaged about 9% of Canadian catches. Harpooneers rely on the swordfish normally coming to the surface during the day.

The question is whether they are basking less due to warmer temperatures below the surface.

Open in mode fullscreen

Troy Atkinson represents the NS Swordfish Association

Industry veteran Troy Atkinson reports that swordfish were being caught off the coast of Newfoundland 20 years ago and may have been under everyone's noses ever since. the beginning.

We suspect the fish have always been present on the Grand Banks, but it didn't make economic sense to travel four days and incur additional expenses when you could catch them closer to home , explains Troy Atkinson, president of the Nova Scotia Swordfish Association. He also wonders if the situation is permanent.

If we continue to see a reduction in landings on Georges Bank and an increase in landings on the Grand Banks in the next five years, then we'll know, he said.

Swordfish follow the Gulf Stream, the great regulating current of the Atlantic, to Canada and feed on squid and other fish in the cold waters around.

< p class="StyledBodyHtmlParagraph-sc-48221190-4 hnvfyV">Kyle Gillespie and Alex Hanke, another Fisheries and Oceans scientist, want to know if the change in their distribution is linked to changes in temperature or changes in movement of current.

It's probably a combination of water temperatures, other environmental factors and prey, acknowledges Kyle Gillespie.

< source srcset="https://images.radio-canada.ca/q_auto,w_1200/v1/ici-info/16x9/bateau-atlantique-peche-quota-mpo-responsabilite.jpg" media="(min-width: 1024px)">Open in full screen mode

DFO wants to track swordfish to better understand these movements.

To track the movement of the swordfish, DFO scientists wanted to attach satellite tags to a dozen of them. They went to the Browns bench and the Georges bench, in September 2023, but they didn't see a single one in places that were hot spots six or seven years ago.

The swordfish tagging operation will therefore be transferred to Newfoundland.

Satellite tags contain sensors that reveal the location, diving patterns and water temperature.

Once the sensors are recovered, they will allow researchers to track movements over a year and compare them to oceanographic conditions.

The goal is to build models of swordfish habitat for entire ocean basins. p>

Kyle Gillespie is working with American and Portuguese research centers to achieve this.

Based on a report by Paul WithersofCBC

Subscribe to the Acadie newsletter.

Form to subscribe to the Acadie newsletter.Subscribe