Money from the federal government’s Environmental Damages Fund will enable researchers to continue studying the impacts of the Mount Polley tailings breach on the Quesnel Lake ecosystem for some time to come.
University of Northern British Columbia professors Dr. Ellen Petticrew and Dr. Phil Owens said they have secured $800,000 in funding, part of which was used this summer to bring in a specialized corer to collect samples of tailings and sediment at the bottom of the lake. The researchers are examining whether tailings deposited at the bottom of Quesnel Lake are loose and if they can re-enter the water column when the lake turns over seasonally.
“Quesnel Lake looks as spectacular as ever but there is a cloud of uncertainty over it,” said Owens, who, along with many other researchers, worked out of the Quesnel River Research Centre over the summer.
“It will be very interesting to see how things unfold. Maybe it won’t be the disaster we think … no one would be happier with that than us, but it’s too early to tell.”
As a result of the 2014 Mount Polley storage breach, the main tailings deposit sits at a depth of about 100 metres below the surface in the west arm of Quesnel Lake and spans four to five kilometres in length, varying in depth from five to 10 metres deep.
A thin halo of sediment stretches much farther, however, from Cedar Point Provincial Park in the west to beyond Cariboo Island and into the deeper water towards the junction heading east.
Petticrew said researchers are assessing the linkages between the physical, chemical and biological impacts of the breach.
“Over the next three years we will be tracing the movement of tailings and sediment both within the water column and into the foodweb. Our scales of investigation range from full lake physical characterization to small scale measurements of metal bioavailablity.”
The research team has continued a detailed monitoring program around Hazeltine Creek and the area around it extending out several kilometres. They have also monitored the quality of sediment below the lake in the Quesnel River. Dr. Petticrew and Dr. Owens will spend the fall and winter months examining the samples and will return to the field for more samples next spring and summer.
“The monitoring has demonstrated that the levels of some metals, such as copper, were still elevated in 2016, with pulses of contaminated sediment entering the Quesnel River that appear to be controlled by the physical behaviour of the lake and hydrological conditions,” says Dr. Owens. “We anticipate that such conditions will continue for several years.”
Owens said many involved in the research are anxiously awaiting the 2018 salmon return which will give some indication how the fish will be affected by exposure to high concentrations of copper.
Non-lethal amounts of copper, he said, can affect behaviours in fish and inhibit them from spawning.
Studies are already underway with Quesnel Lake zooplankton to determine if the heavy metals are entering the food web.
Owens said UBC and UNBC are teaming up with researchers from the University of Lethbridge on the studies.
“We are going to be able to determine what the short, medium and long term effects are on the environment form the breach.”