What started as a master’s thesis continued beyond her degree and research scientist Erin Sexton has seen her teams work hit headlines and effect policy on both sides of the US-Canadian border. Sexton works with the Flathead Lake Biological Station and has been focusing on the water quality of the Flathead River Basin, specifically the North Fork of the Flathead. She was recently recognized with the Montana Chapter of the American Fisheries Societies Conservation Achievement Award for 2012.
The North Fork of the Flathead River has its headwaters in British Columbia flow from mountains rich in coal, gold and coalbed methane. The North Fork is designated a “wild and scenic river” and threatened Bull Trout live in its waters with their spawning grounds also near the headwaters across the border. Sexton said while working on her master’s thesis in 2002 there was discussion of coalbed methane development for the section of British Columbia near the headwaters of the North Fork of the Flathead River. Her thesis looked at the type of changes that would be seen in a watershed draining off of open pit coal mines. She and other researchers from the biological station, Montana Fish, Wildlife and Parks, and the U-S Fish and Wildlife Service gathered baseline information on the Flathead River.
“So, for example, you look at the full suite of metals. You look at Cadmium, Barium, Copper, Selenium. These metals and elements basically leach off of open pit coal mining, so we wanted to see what the signature was of these in the watershed in a pre-mining condition,” Sexton said what they found in the North Fork was a relatively pristine system with low nitrate and sulfate levels.
Sexton said what you see in the rivers downstream from a mine is the underlying geology coming to the surface with higher readings for nitrates and sulfates. In the process of collecting data on the North Fork they looked to compare it to a river that had seen open pit coal mining upstream. They used the nearby Elk River in Canada which runs into Lake Kookanusa and the Kootenai River system. The Elk River recently made headlines after being identified as one of the most endangered rivers in British Columbia. Sexton said they measured 10 times the amount of Selenium in the Elk as the Flathead, 50 times the sulfates, and 1,000 times the nitrates.
“We’re particularly concerned about nitrates and phosphates and sulfates in the Flathead watershed. If you have too many nitrates in a system you’ll get a ‘greening up’ of your watershed because it feeds the algae in the system,” Sexton said.
The research continues. Sexton said moving forward she anticipates an increasing focus on the Elk River and the Kootenai system as legislation on both sides puts many mining questions for the Flathead to rest. However, she said questions about best management practices for cross-boundary natural resources will continue to evolve.