High E. coli levels in waterways attributed to bacteria in the soil, more storm events

Several swimming spots have been closed in the province due to high E. coli levels and, according to a University of Guelph professor, climate change will likely make these occurrences more common.

As of Friday, Campers' Beach at Mactaquac Provincial Park, near Fredericton, and Oak Bay Provincial Park in southwestern New Brunswick, remain closed for swimming due to elevated E. coli test results.

On Wednesday, the City of Saint John announced the temporary closure of Lily Lake, Fisher Lake and Little River Reservoir for swimming.

On Thursday, the Town of Quispamsis said on social media that routine samples from the Department of Health revealed elevated E. coli levels for Gondola Point Beach and Ritchie Lake. The post advises people and their pets to stay away from the water until further notice.

Keith Warriner, a professor in the department of food science, said rising temperatures mean E. coli survives longer, and more frequent storms can cause more runoff or agitate pathogens already in the soil.

"Certainly people are very concerned about climate change and pathogens," he told Information Morning in the Summer. "We're certainly going to see them more frequently, I think, compared to other times."

He described E.coli as a bacterial group, most of which are harmless, but a subset of the bacteria contain pathogens that can cause illnesses, such as norovirus and salmonella.

"When they look at E.coli and find it in water, that's not pathogenic per se," said Warriner. "But it certainly could indicate that you've got fecal contamination with all these pathogens that can make us ill."

When it comes to what could cause the elevated levels of bacteria, Warriner said older research focuses on runoff from farms, but current research shows that E. coli is often in the sediment, and storm events or rising water stirs it up.

In those instances, it doesn't make sense to wait for the levels of bacteria to come down.

"I think what the real problem is, is that we're relying on 1900 indicators and methods, when we've got much more modern methods we could use to identify the pathogens directly, rather than depending on the indicator," said Warriner. "Because for a long time, you know, people always said well, E. coli is not the best indicator."

Warriner said even if you know E. coli is present, what to do about it is the bigger question.

In the meantime, he recommends swimmers contemplating an outdoor dip consider the landscape around the body of water and the history of posted water-testing results.

"If you've got rivers going into the lake and there's farms there, that's one thing," said Warriner. "You certainly can look at the website to see how often these E. coli closures go ... but certainly any sort of rivers, any sort of lakes, is always going to be a risk."