Milfoil hits hard, early

by Nicholas Johansen CASTANET - Jun 16, 2015 / 3:30 pm

That may not be the Ogopogo grabbing at your feet in Okanagan Lake this summer. The invasive aquatic weed, Eurasian Milfoil, has turned up in the Okanagan earlier than usual, thanks to the hot weather and the early spring run-off from the mountains. “We spent extra time on the water over the winter trying to get ahead of the summer growing season, but we just can’t compete with the changing climate,” said James Littley, operations and grants manager for the Okanagan Basin Water Board. While he said there has been a steady increase in milfoil in recent years, this year is particularly bad. From a tourism perspective, unchecked milfoil growth can have serious economic impacts. A 2014 study of 1,258 American lakeshore properties found that milfoil results in a 19 per cent decline in mean property values. But milfoil does more than just keep tourists out of the water. There are environmental problems the invasive weed brings with it as well. “It robs oxygen from the water and takes nutrients out,” said Littley. “It’s basically bad for water quality, it can increase toxic algae blooms, it can cause fish kills and it crowds out other native species.” In the winter months, the OBWB uses a rototiller to churn up six to eight inches of the lake floor, which kills the weed. In the summer, crews simply cut the weed six feet down, to keep the weed from the surface. But milfoil can grow at an alarming five cm a day. “By the time we cut it six feet down, within a month it's back at the surface again,” Littley said. Milfoil removal is prohibited near the mouths of creeks until July 21, due to fishery restrictions. "Because it's (starting) earlier and we're not allowed to start until the normal time, there’s gonna be a month or two where it's bad,"Littley said. The OBWB has battled milfoil in the Okanagan lakes for 41 years and spent a total of $18 million. Littley said the origin of the invasive plant is unknown, but it is sold as an aquatic plant for fish tanks so it could have been introduced when someone emptied their tank. It could also have been brought over on someone’s boat.For more information on the OBWB’s milfoil program, visit www.obwb.ca/milfoil.