Less ice in the Gulf of St. Lawrence
Coastal erosion could increase if the trend continues in coming winters
Ice coverage in the Gulf of St. Lawrence over the winter has been recorded as one of the lowest years in documented history.
Environment and Climate Change Canada (ECCC) has been documenting decreases in annual coastal ice forming in the Gulf of St. Lawrence for more than 20 years.
George Karaganis, a senior meteorologist at ECCC, showed Saltwire data collected by the Canadian Ice Service that has tracked the decline in ice coverage in the Gulf of St. Lawrence in recent years.
“Looking at the start and end dates for ice accumulation, there is a pattern of a decreasing period of ice cover along the P.E.I. coast,” Karaganis said on Feb. 27.
With mild winters, wild temperature fluctuations and unexpected cold snaps, P.E.I. has no shortage of inland, freshwater ice during the winters. But coastal ice is on the decline, ECCC meteorologists say.
ECCC says ice offers protection to the coast and acts as a shield against erosion from waves and strong storms throughout the winter months.
Environment Canada statistics warn that as coastal ice levels continue to decline, coastal erosion will increase.
“Air temperature is the main driver of sea ice formation; however, sea surface temperatures also play a role. This season saw ice formation delayed in the gulf, as was the case last year,” Karaganis said.
ISLAND ICE
Genevieve Keefe, a UPEI PHD student of environmental sciences, told Saltwire on Feb. 23 that unlike inland, freshwater ice, the requirements for ocean ice are much higher.
Keefe has been studying coastal ice for several years at the Canadian Centre for Climate Change and Adaptation, and has noticed a recent trend in coastal ice around P.E.I.
“There is so much variability from year to year, but it does seem like (coastal ice quantity) was relatively consistent until about 25 years ago,” Keefe said.
Keefe said the freezing temperature for coastal waters is approximately -1.8 C, which further complicates coastal ice formation. Keefe said the average consistent temperatures on the coasts of P.E.I. have been very close to this freezing temperature, hindering the thickness and quantity of ice that can form.
“Given the global climate projections and regional climate predictions we are expecting the temperature to continue to increase, and of course that is going to further decrease the amount of ice that we see,” Keefe said.
Coastal ice takes longer to form and is easily broken up by weather conditions compared to freshwater ice.
This is due to the salt, which increases the freezing temperature of the water,
Keefe said.
This decrease has been interrupted with a few abnormally icy seasons, Karaganis said, but overall trends show there has been a decrease in sea ice since 1994.
“Though the gulf does still get years with above average ice amounts, the last time was in 2018 and 2019,” Karaganis said.
Isabelle Comeau, communications advisor for Fisheries and Oceans Canada and the Canadian Coast Guard (CCG) in the gulf region, issued a statement to Saltwire on Feb. 28 regarding icebreaking activities in and around Port Charlottetown.
“The CCGS Louis S. Stlaurent, a heavy icebreaker, is currently on standby in the Charlottetown Harbour to quickly and efficiently respond to icebreaking requests from the shipping industry,” the statement read.
Comeau said that so far, the icebreaker has escorted three tankers into and out of Port Charlottetown this season.
“Even though we’re noticing a significant reduction in ice coverage across the southern Gulf of St-lawrence this winter, CCG hasn’t experienced a corresponding significant reduction in the delivery of icebreaking services in Prince Edward Island.”
Total icebreaking operations are calculated by region, rather than province, therefore when asked, Comeau said the CCG does not have statistics regarding the extent of the decrease in icebreaking off the coast of P.E.I. and in the Gulf of St. Lawrence.