CANMORE -- They’re a husband and wife team who have been conducting research in the Canadian mountain parks for 14 years.
Mark Olson is a fish biologist and his wife Janet Fischer studies smaller aquatic creatures. The two started out looking into the impact of ultraviolet radiation on underwater life.
Their focus shifted seven years ago when they started looking at water transparency. They initially thought all alpine lakes would be similar but soon learned differently.
In the summer months the couple are joined by their two children and students from Franklin and Marshall College in Lancaster, Pennsylvania, where the two are based, to collect data.
The two are back in the area a little out of season this year, in order to host a free talk on their findings that takes place Tuesday, January 28 at 7:30 p.m. at the Banff Seniors Centre. It’s presented through the The Bow Valley Naturalists and its 2020 speaker series.
That data they have been collecting for close to a decade and a half involves measuring mid-summer transparency, turbidity and dissolved carbon concentration in a set of 17 lakes. Eight are glacially-fed while nine are not and they vary in catchment composition.
They try to be consistent in their data collection by visiting the same lake on the same day annually using specialized electronic sensors.
Mark Olson said, “We can measure light, different wave lengths of light, measures at four times per second as we slowly lower it into the water and that allows us to measure the transparency in terms of how much light there is at each depth."
Unique colour
Janet Fischer says glacier-fed lakes get their unique colour from the powder left behind from the heavy ice sheet sliding on the mountain surface. It’s referred to as ‘flour’. The other determining factor for lake colour is organic material.
“The vegetation in the watershed as it decomposes releases carbon which is dissolved and coloured and that material makes its way into the lake as well,” said Fischer.
The researchers are seeing a decrease in turbidity that they say is likely caused by the shrinking of glaciers in the catchment due to climate change.
Olson and Fischer say as glaciers abate, meltwater inflows to alpine lakes will decrease. This decrease will in turn reduce inputs of glacial flour leading to an increase in transparency and change in colour.
“What we have found is the turbidity in these lakes which is caused by the glacial flour has decreased dramatically in six out of the eight lakes,” said Fischer.
Olson and Fischer are continuing their research this summer and hope people take notice.
“Human action is accelerating the rate of glacial loss and so by addressing climate change in a really ambitious way we could slow that natural process or slow our impact on that process,” said Fischer.
She says if we’re able to slow that loss future generations will be able to enjoy the stunning turquoise colour of some of our most famous alpine lakes.
