Anglers interested in having extensive depth charts and fish population profiles of local lakes will soon have that information thanks to research by Derek Gray out of Wilfrid Laurier University.
Gray and a team of students have been studying lakes in the area, including Boot Lake, Shell Lake and Airport Lake, with plans to extend their research up to Tsiigehtchic this year, to Fort McPherson the next and from Inuvik to Tuktoyaktuk in the third year.
“We’re trying to collect a bunch of data from each lake,” said Gray. “There doesn’t seem to be much information on the fish species that are present in those lakes, how abundant they are, how many you can find in the lakes.”
The idea is to eventually be able to share depth data, fish data and water quality data with people in the region.
Gray was surprised at the diverse fish population in Boot Lake.
“Local fishermen probably know this, but there are a lot of whitefish in the lake and very large pike,” said Gray. “We caught one pike that was 17 pounds from that lake, which I think any fisherman would be happy to pull in.”
Some of the other lakes, such as Shell Lake, don’t seem to have such a diverse population. Shell has mostly pike with some pond smelt, he said.
“Boot Lake has really been interesting for us because it had such a high abundance of fish present in the lake.”
He and his team take about 20 fish fillets per lake to send back to the lab for analysis for mercury and other heavy metals.
Gray was also surprised to find zero fish life in some of the smaller lakes along the Dempster Highway. He attributes that possibly to those lakes freezing completely over during winter with no room for fish to survive.
For the bigger lakes, the ice surface in winter acts as an insulator.
“The fish have pretty slow metabolism for the winter,” said Gray. “They don’t eat quite as much as they do in the summer months, and they’ll hang out usually at the bottom of the lake, insulated from the harsh winter weather.”
Water is densest at four degrees.
“Water’s a weird substance,” said Gray. “When it freezes at zero degrees it floats like an ice cube, but when it’s exactly four degrees it’s the heaviest. So that four-degree water sits on the bottom of the lake and the fish can hang out there.”
The lakes of the region seem free from some of the agricultural runoff present in southern lakes, he added.
Much of Gray’s work is centred around any impact climate change will have on local lakes. He’s establishing a baseline of information now that can be referred to in the future.