Manitoulin Island beekeeper looking for answers after toxic herbicide detected in dead bees

Janice Mitchell was prepping her bee colonies for what she thought would be another regular winter season on Manitoulin Island.

Come February, Mitchell had a nasty surprise when she discovered that 90 per cent of her colonies had died. 

"I'll frequently check my colonies and just listen outside the wraps and I knew something was up," said Mitchell, a hobby beekeeper and veterinarian. 

"They were awfully quiet."

On average, Mitchell says at the height of her beekeeping, she had 25 colonies. Last year she only had 18, and about 16 had been decimated.

In previous years, the mortality rate for her colonies averaged around 10 per cent.

"It was my biggest loss. That's when I knew something had changed."

Janice Mitchell sent her dead bees to the University of Guelph’s agriculture and food laboratory for necropsies and further testing. (Submitted by Janice Mitchell)

Mitchell opened up the dead bees for a necropsy and found no signs of starvation, mold or moisture problems, no signs of wing deformed virus, and minimal varroa mites — a parasite of honey bees. 

So, she sent them off for more testing at the University of Guelph's agriculture and food laboratory. Turns out, the lab detected 0.57 milligrams of glyphosate, a herbicide used to control troublesome weeds, in the dead bees. 

Research from Europe's Pesticide Action Network says exposure to the herbicide in concentrations between five to 10 milligrams, similar to those found in the environment, reduces beneficial gut bacteria in honey bees and dysregulates their immune system. 

The acceptable level of glyphosate in drinking water for humans is 0.28 milligrams, according to Ontario's drinking water standards. 

According to Mitchell, when she asked for a glyphosate test for her dead bees, she was told that the lab had never done that before. 

"That was quite profound for me. I was thinking 'how are these chemicals getting approved and how are beekeepers not testing for this in bee's bodies?'" Mitchell said. 

Janice Mitchell said this past winter marked the 'biggest loss' when she discovered 90 per cent of her bee colonies had died. (Submitted by Janice Mitchell)

Now, she's spreading the word and ringing alarm bells for what this means for wild bees and pollination. 

CBC News reached out to the University of Guelph's Honey Bee Research Centre for comment. They could not respond in time for publication.

At this point, it's not clear where the chemicals came from. However, bees' radius for foraging is five kilometres. 

Northern Ontario apiaries looking for answers

Last week, CBC News reported a story about a beekeeper in Lively, Ont. who is raising money to run tests and necropsies after she discovered 1.2 million bees suddenly dropped dead at Mikkola Family Farm & Apiary.

Testing can only happen through a user-pay system.

Dawn Lalonde said all proceeds would go toward identifying and eliminating the source of the problem. 

The abrupt and violent nature of the deaths, combined with discussions with other local beekeepers, led her to conclude something in the environment could be to blame.

"It was an acute kill, which is most likely from some type of chemical used in the area," she said.

Dawn Lalonde was hoping to grow her bee colonies this year, but is now facing the sudden and unexpected loss of 50 per cent of her operation. (Aya Dufour/CBC)

Ian Grant, president of the Ontario Beekeepers Association, told CBC News that mortality rates in apiaries have been particularly high coming out of the winter. 

"This year we have been hearing about large losses in the beekeeping community and we can't attribute it to any particular issue," he said. 

However, Mitchell said education plays a important role in preventing bee deaths caused by agrochemicals. 

"I pass the gauntlet to academia and researchers. This should be taken on and analyzed," said Mitchell.