“Losing the blue”: why mountain lakes are losing their color

A new short documentary filmed in Alberta's Banff National Park and British Columbia's Yoho National Park attempts to capture the effects of climate change on mountain lakes.

a documentary called Blue lossFilmed from 2020 to 2023 at 10 different alpine lakes including Lake Peyto, Lake Moraine and Lake Louise.

“This movie is basically about a dying color and what does it mean to lose it?” Director Leanne Allison said.

The documentary is told through a cinematic poem, trying to create an emotional connection to the disappearing color of the lakes.

“All lakes are created by glaciation, volcanic activity and things like that,” Ellison said. “All lakes eventually die of sedimentation.”

“I felt like we had more in common with the lakes than I thought.”

Alpine lakes offer stunning blue colors through particles of melted glaciers. As they are shrinking, the lakes are showing the effects of climate change.

“It's that classic Peyto Lake blue or Lake Louise blue, people come from all over the world to see these lakes and the colors, and the wonderful, shimmering quality in the lakes can be attributed to that (glacial flour).” said Janet Fisher, scientific advisor Blue loss.

“Glacial flour, which is finely ground mountain dust, so when the melt goes down, there's less of that material going into the lakes, and that changes their color.”

Both Fisher and research consultant Mark Olson have spent the past 17 years studying lakes in the Canadian Rockies and have spoken to many people during that time.

“I would say we're connecting the dots. The land and the lake are really connected. So what's happening with the glacial ice on land affects what we see in the lake,” Fisher said.

In the work of other researchers, they saw that the melting of glaciers accelerates every summer.

“Anytime you change the amount of meltwater that goes into these lakes, there are consequences,” Olson said.

The pair approached Ellison about making a short film with two stipulations: they wanted it to be more than a traditional science documentary, and they didn't want to commit to it.

“Film allowed us to translate what we saw into something that people could see,” Olson said.

“The idea for the film came about because we hoped to do a better job of sharing our research and findings with the public,” Fisher said.

Allison said there were several remote lakes where the crew had to hike in different areas of the parks. Help save remote lakes Blue loss due to their specifics, the crew chose not to open them.

“I spent 10 days alone in the mountains, sitting by these lakes, filming them and getting to know each lake,” Allison said.

He noted that climate change is not the only factor affecting the lakes, as filming had to be halted in 2021 due to wildfire smoke.

“I thought it was always going to be there,” Allison said. “I didn't think that heaven wasn't something that would last forever.”

The 16-minute film is a National Film Board of Canada feature that can be viewed online for free.