Climate change, eroding shorelines and the race against time to save Indigenous history

On the shores of Leamy Lake Park along the Ottawa River, with Parliament Hill on the horizon, there's a flurry of activity.

Spades are gently digging and scraping through the earth. Sand is being poured through sifters. Mud is being washed away — all in the hopes of finding a piece of history.

Archaeologists have known the historical significance of this site for years. The area, managed by the National Capital Commission (NCC), has been known to contain artifacts older than the pyramids, according to researchers.

It is definitely sad as an archaeologist to literally see artifacts falling into the river, never to be recovered again.- Monica Maika, NCC archaeologist

Indigenous communities would use the rivers and lakes around what's now the National Capital Region as highways, travelling by canoe to meet and trade goods, according to Jennifer Tenasco, a member of Kitigan Zibi Anishinābeg First Nation.

"Lake Leamy is what we call Kabeshinan, and it means campsite or gathering site, a place that we've gathered or our ancestors have gathered on," she said.

Tenasco is also a supervisor of the Anishinābe Odjìbikan field school, which partners with the NCC on archaeological digs, to help uncover parts of Indigenous history.

"The land is very important and it tells our story and it tells our history," Tenasco said,

But over the years, the objective of these archaeological digs has changed: It's no longer just about discovery. 

The goal now is to find and save as many artifacts as possible before they become the victims of erosion — and time is running out.

"We're seeing the water literally eat away at lower levels of clay, and what that's doing is undermining the soil and causing giant chunks of clay to fall off the side of the site," said NCC archaeologist Monica Maika.

History lost

Maika is one of the archaeologists witnessing first-hand the toll climate change is having on shores and coastlines.

"Mother Nature can be a pretty cruel mistress sometimes," said Maika. "We're doing our best to get ahead of her and try and learn as much as we can about this, but it is definitely sad as an archaeologist to literally see artifacts falling into the river, never to be recovered again."

In one case earlier this year, an NCC archaeologist discovered an Indigenous-made pot estimated to be up to 1,600 years old at another site in Leamy Lake Park, but Maika said only half the artifact could be recovered because the rest had already been swept away to the bottom of the Ottawa River.

And it's not just artifacts at risk. The soil in which they're found provides a lot of context for archaeologists, including when and where human activity took place. When that soil is disturbed by waves or powerful storms, those clues disappear.

"My worry is that we're going to lose information faster than we can learn about it," Maika said.

Erosion occurring at alarming rate

Shorelines and coastlines across Canada are disappearing at an alarming rate.

According to Chris Houser, dean of science at the University of Waterloo who specializes in earth and environmental science, it's caused by a combination of factors: rising sea levels, an increasing frequency of powerful storms and the loss of sea and lake ice as temperatures climb every year.

In some environments, shore and coastlines lose tens of centimetres per year, while others can lose up to several metres.

While nature does find a way of recovering, "it's always like a two steps backwards, one step forward type process," Houser said.

He said it's also difficult to get a complete picture with little historical data to track erosion, and with fewer students choosing to pursue environmental sciences as a field of study.

Making difficult decisions

"The world is in the grips of an unmitigated heritage crisis caused by climate change," said Matthew Betts with the Canadian Museum of History, who also chaired the climate change committee of the Canadian Archaeological Association.

With the world's longest coastline and largest freshwater ecosystem, where many archaeological sites sit, "Canada sits at the apex of this crisis," he said.

The NCC laid out the risks to local archaeology in a 2022 report. It warned not just of erosion, but also freeze-thaw cycles disrupting soil and extreme heat sending people to seek relief along the same shorelines where artifacts are found.

Betts estimates thousands of sites across the country "are being indiscriminately washed away," with many disappearing before anyone has even had a chance to discover them.

And with limited time and resources to salvage material, he said that's forcing Indigenous communities to make difficult decisions.

"Indigenous people have to be forefront in making the decisions about which sites to salvage, i.e. what history to save," said Betts.

It's a terrible choice to have to make with Indigenous people already "wiped away through residential schools and systemic racism," said Tenasco.

To find anything connected to their ancestry is of significant value, she said.

"We don't want it to be washed away or wiped away by the river."

Ottawa Morning7:13Archaeologists say climate change is creating a race against time to recover history

We talk to Dr. Matthew Betts, curator of eastern archaeology at the Canadian Museum of History and former chair of the climate change committee for the Canadian Archeological Association, to learn more.