| Sourced from 2 independent sources (4 reports) · no points in dispute |
miragenews.com (1) and UBC News
Most key facts are confirmed by more than one independent source; a few details come from a single outlet.
10 key facts · 9 corroborated · none disputed
Why some reports were counted once
UBC News, EurekAlert!, and miragenews.com (2) — the same report, published near-identically, counted once.
When several outlets publish the identical article — often because they ran the same wire-service story — we count it as one source, not several, so the count reflects independent reporting rather than how widely one story was republished.
This summary is compiled from the independent sources listed above.
Canada’s last intact epishelf lake is gone.
When the Milne Ice Shelf broke apart in 2020 on northern Ellesmere Island in Nunavut, it removed the ice barrier that had held the Milne Fiord epishelf lake in place. Within months, the lake’s freshwater drained into the ocean, ending a rare layered ecosystem with freshwater life above and a marine ecosystem below.
Canada’s last epishelf lake
Epishelf lakes form when an ice shelf dams a fjord, trapping a freshwater layer above seawater that remains connected to the ocean. At Milne Fiord, that arrangement created two ecosystems stacked on top of each other.
“Epishelf lakes are remarkable because a freshwater ecosystem sits directly above a marine one, separated only by a thin boundary between fresh water and salt water,” said Dr. Andrew Hamilton, an Arctic oceanographer at the University of Alberta and a co-author of the study. “When the ice shelf broke apart, that unique ecological structure disappeared. It was the last of its kind in Canada.”
The study, published in Scientific Reports, is the first complete reconstruction of the lake’s drainage and transformation from a freshwater ecosystem into a marine environment.
The breakup that changed everything
The ice shelf and lake had been thinning for decades before the 2020 breakup. Researchers say that breakup was the decisive event: the ice shelf no longer held back the freshwater layer, and the lake drained into the ocean within months.
“The ice shelf and lake had been thinning for decades, but the 2020 breakup was the last straw,” said co-author Dr. Jérémie Bonneau, a professor of civil and water engineering at Université Laval. “The lake drained within months.”
That drainage ended the lake’s defining feature: its layered structure of freshwater life above a marine ecosystem below. Hamilton described the lost system as “phenomenal,” recalling fieldwork in which researchers found marine life beneath the ice shelf.
“We found a robust marine ecosystem with brittle stars, sea anemones, scallops, etc., all living in complete darkness in a channel at the base of the ice shelf,” he said.
How scientists reconstructed the loss
The reconstruction drew on work by researchers from the University of Alberta, UBC, Université Laval and Carleton University. The team used long-term ocean instruments, annual water profiles, satellite imagery and field observations to piece together what happened before and after the lake disappeared.
Dr. Derek Mueller, a professor of geography and environmental studies at Carleton University, said that kind of record required repeated work in difficult conditions.
“There are much easier places to conduct research, but understanding change in the High Arctic requires returning year after year,” Mueller said.
That long-term monitoring gave researchers the evidence needed to track the lake’s transformation after the ice shelf broke apart.
No recovery in sight
According to UBC News, by July 2022, brackish water had replaced the lake’s freshwater layer. UBC News also reported that later monitoring found no sign of recovery.
Dr. Bernard Laval, a professor of civil engineering at UBC and a co-author of the study, said the loss shows how closely the lake’s survival depended on the ice shelf.
“Epishelf lakes can signal when an ice shelf is under stress, and that’s what we saw here,” Laval said. “The data showed the ice shelf was failing. Once the ice is gone, the ecosystem goes with it. There’s no coming back.”
Researchers say the ice shelf that contained the lake cannot recover under the current climate trajectory. As a result, the lake will not return on human timescales.
“These systems took thousands of years to form and were lost in months,” Bonneau said. “On any human timescale, they are not coming back.”
A warning from the Last Ice Area
The Milne Ice Shelf lies within the Last Ice Area, a region expected to retain perennial sea ice longest in the Northern Hemisphere. It is also within the Tuvaijuittuq Marine Protected Area.
That location makes the lake’s disappearance especially stark. The place expected to hold onto perennial sea ice the longest has now lost Canada’s last intact epishelf lake.
For Hamilton, the loss is not abstract.
“My kids are never going to see that kind of ice shelf and lake system in their lifetime,” he said. “It’s the end of an era.”
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