Record temperatures in the Gulf of St. Lawrence in 2021
St-Lawrence river near St-Jean-Port-Joli, Quebec, Canada
The Gulf of St. Lawrence broke temperature records in 2021 at all its depths, said Fisheries and Oceans Canada researcher Peter Galbraith at a scientific conference on the oceanographic conditions of the Gulf of St. Lawrence. This was presented at the Maurice-Lamontagne Institute in Mont-Joli.
For 16 years, Mr. Galbraith has been compiling data for the entire Gulf of St. Lawrence with his teams. Whether it is the temperature of the air, of the water at different depths or the volume of the ice, many readings taken in 2021 surpass records that are sometimes centuries old.
“I think after 2021, the state of the ocean 2022 is going to be flat. We had records in all layers. It’s my 16th ocean state, it’s the most out of the ordinary. We've been talking about century-old records at depth for several years, but this year was truly iconic for the hottest cold intermediate layer in 40 years. It's going to be interesting to see the impact on all the [living] fisheries resources. It’s been a big year for the gulf,” he explains.
For example, the volume of sea ice recorded in 2021 of around 11 km3 is close to the low record set in 2010. “Most of this ice was very thin, under 10 cm”, specifies the researcher. November and October were the warmest months since 1981 in terms of sea surface temperature. Below, in what is called the cold intermediate layer, it was also the warmest in 40 years. Finally, in the deep waters, the waters recorded temperature records at all depths (from 150 m to 300 m) of about 2.3° to 2.7° above average.
It’s the temperatures recorded in the cold intermediate layer that surprised him the most. “Unheard of,” he says. When the ice melts, this layer of cold water becomes trapped about 75 meters deep. “Usually even in August if you put a probe in the water you can find water below freezing. This year, the waters remained super warm, as we had little ice formation.”
The researcher, Peter Galbraith – Courtesy
These upward temperature trends have been remarkable for the past ten years,
Mr. Galbraith. “Since 2009, we have shown this increase year after year. It’s a straight line. The average temperatures at depth in the gulf rose from 5.2° in 2009 to 6.7° in 2021.
Difficult for the researcher to position himself as to the consequences of these data. The answer will rather fall to biologists as far as ecosystems are concerned. “I am often asked to put on color indicators. are you good? Are you serious? We have trouble with the temperature of the water, because what is good for one species is not good for another.