Hope for Climate Change From Canada's Arctic Ocean

Peta Mudie builds on her early discovery of climate change

June 2020

After an impressive career spanning five decades, four countries, three continents, several oceans and countless adventures, you might expect Peta Mudie ready to take a rest. You would be wrong.

Now an emeritus scientist at the Bedford Institute of Oceanography in Dartmouth, Nova Scotia — a Government of Canada ocean research facility and the largest ocean research station in Canada — she speaks with a measured urgency: "We're basically in a new era. We used to look to the past to predict what would happen in the future."

She's referring, of course, to climate change, and she's speaking with her typical passion for the need for action, now: "We're at a tipping point where we've passed the ability to have great certainty in forecasting what's come for the future."

The topic is close to her heart and one, it so happens, that she first began to explore as a child.

A girl, a microscope and a glimpse into a special world

Growing up in Durban, South Africa, Peta explored the jungle wilderness with her father, a forester. She saw the immense world of nature first-hand and close-up, including elephants and baboons being squeezed into ever smaller habitats by the pressures of the expanding city.

But she was always more interested in the small things of life, and a microscope she received as a gift at the age of eleven ignited her imagination. She spent hours studying lichens and their peculiar relationship to the intertwined worlds of microscopic algae and fungi.

"I would cut them open and try to see what was inside and how they were working together," she says. "Exploring the tiny world was the way I saw and understood the world."

And with those first steps began a lifetime of scientific discovery.

Due north for more adventure

After stops in California and England, and with two young children in tow, Peta eventually arrived at Dalhousie University in Halifax, Nova Scotia, to pursue a PhD in geology.

Her thesis was groundbreaking. No one at that time expected to find dinoflagellates — single-cell marine plankton propelled by two whip-like projections (flagellae) — in the ice-covered Arctic Ocean, but her research in Baffin Bay, off Baffin Island, Nunavut, confirmed their presence. And she became the first to show how these marine fossils, and wind-blown pollen found in layers of sediment below the seafloor, could provide evidence of historic climate change in eastern Canada.

Armed with this knowledge, Peta joined Natural Resources Canada as a research scientist, where she continued to study climate and environmental dynamics. Here, she joined a dedicated and adventurous team.

Drilling down to measure a changing climate

The international Deep Sea Drilling Program had already shown great potential, and deep-sea coring of ancient sediment samples became more feasible. While onboard the drill ships, Peta developed new ways to study fossil pollen and single-cell aquatic organisms to help date the core sediments and gain more detailed insight into past climate change and ocean circulation patterns.

She was the project leader on the 1980s Ice Island expedition, joining the first group of Canadian scientists who used a drifting iceberg in the Arctic Ocean to study the sea floor north of Ellesmere Island in Nunavut, the world's tenth-largest island and Canada's third-largest, containing the country's most northerly point.

The conditions were challenging, and the site was unpromising. "We were not expecting a very diverse sea floor biology in this area, which is inaccessible by ship due to seven metres of pack ice cover year-round," Peta says. The team built a special base camp on a unique piece of floating shelf ice 40-metres thick, and then had to figure out how to bore a hole through the ice so they could lower cameras and sampling instruments down to the sea floor.

A stunning surprise at the bottom of the sea

The dark, icy waters far below the pack ice contained a great surprise. "Completely contrary to our expectations, we found there was a huge diversity of sea floor animals there and, in particular, they were not coral reefs, they were glass sponge reefs," she recalls. "But these huge reefs were dying — why were they dying?"

Concerned and curious, the team took a closer look. Oceanographers measured seawater temperatures and salinity levels down to the deepest points. What they discovered was mind-blowing at the time: It appeared the ocean was becoming too warm for the glass reefs to survive.

"This was the first canary in the coal mine basically, the first look at intense global warming," she says. "It was already impacting the Arctic much faster than the rest of the world."

Since that early discovery, her work has taken on greater urgency.

Blazing forward with Arctic research, even in retirement

"The issue now is the speed at which these changes are happening because of what we call commotion in the ocean and the speed at which things are changing season to season and year to year. That's where we are now — we're in a new world of uncertainty."

But in uncertainty there is still hope. "I think all scientists are basically motivated by curiosity and by trying to help make things better," Peta says. "And as long as there are opportunities to do that, that's what we do."

Looking back, the microscope that Peta received as a child has proven itself to be a great investment — for her and a long career of research and for our world and its future.

For more information:

• Canada in a changing climate
• Climate Change (Natural Resources Canada)
• Climate Change (Government of Canada)