‘Mosquito annoyance’ rising along Fraser River amid high water levels, low temperatures

FRASER VALLEY (NEWS 1130) — Lower temperatures and higher water levels in the Fraser River have led to the worst mosquito season in Metro Vancouver since 2012.

Since the start of May, the Fraser River has peaked and flooded three times along parts of the waterway, creating large pools of standing water — the main breeding ground for mosquitoes.

“It’s all directly related to the higher than normal Fraser River, it’s definitely higher than we’ve seen in a while. The other issue is we’ve seen three separate peaks, and each peak in the Fraser River has been higher than the previous peak, and every single time we see a higher peak it translates to another batch of mosquitoes hatching,” says Shaun Culver with Morrow Bioscience, which is in charge of mosquito control in Metro Vancouver.

“We’re experiencing higher than normal numbers of mosquito annoyance for everybody who is living close to the Fraser River.”

Culver says the coming week will likely determine if his team will be activated again to deal with a fourth peak of the river.

“That [will] obviously dictate that we need to get back out there and again apply the granules to attempt to control as many mosquitoes as we can in their larval form,” he notes.

When water levels are low, crews go out and apply larvicide by hand. As levels rise they adapt their approach by employing canoes and then helicopters.

“It’s non-toxic and target-specific, meaning it specifically targets mosquito larvae and nothing else. Our goal is to get as many of the larvae as we possibly can,” he says.

Cooler temperatures are also responsible for prolonging mosquito season.

“What we really want to see is higher temperatures for the month of July, and that should kill these adult mosquitoes off faster, but we’re still looking at several more weeks of not great mosquito conditions.”