More than half-a-million lake weeds were systematically pulled from the bottom of Christina Lake last summer, during a 20-week blitz undertaken by the regional district to keep the spread of the invasive milfoil plant in check.
According to a November report from the Regional District of Kootenay Boundary, a team of divers spent five months scouring the sand and rocks, predominantly at the south end of the lake, to pick a total of 535,135 weeds.
“The method of control utilized by the divers is manual hand removal of the plants, with the best efforts to remove all of the roots, just as one does in their garden,” the report explains.
Eurasian milfoil, which was detected in Christina Lake in the mid-1980s, is an invasive species that can grow at a rate of 30 centimetres per day during the summer time and deter people from fishing, swimming or boating on certain areas of the lake.
“Dense surface patches of milfoil can negatively affect waterfront property values because swimming and boating are hindered, aesthetic values are reduced, and decomposing plants produce foul smelling gasses,” the RDKB report reads.
Given that tourism is a major economic driver for the community at the lake, milfoil control has been made to be an equal priority and in 2019 was given a budget of $309,234.
2019 marked the 33rd consecutive year that divers had pulled the weed from the lake. Since 2015, divers have pulled an average of nearly 439,000 plants from the lake.
Significant patches of the tenacious plant, which thrives in water under 10 metres deep, can also choke out other species from the lake ecosystems.