Environment featured Weekend Video

Weekend video: How mercury left behind at old Nova Scotia gold mining sites continues to enter the food chain

KJIPUKTUK (Halifax) – Where there once was a gold mine there are likely mercury deposits, because that’s what miners used to separate the gold from the rock.

In this short 2018 video Molly Leblanc, a species at risk and biodiversity biologist with Coastal Action, talks about the roughly one million ounces of mercury left behind by mining companies in Nova Scotia, typically dumped in nearby wetlands.

Mercury is a neurotoxin, exposure to mercury – even small amounts – may cause serious health problems. Leblanc talks about fieldwork she has done here in Nova Scotia that shows that mercury left behind at old gold mining sites continues to enter the food chain.

“Today, there’s thought to be 3 million tons of this sand-like mercury-rich mining waste left in wetlands across the province in Nova Scotia alone. And there are sites like this all across the country.

“Despite that, though, hardly anyone is researching the effect these sites have on the species living nearby. So that’s where my work comes in. I’m starting with the little critters low on the food chain, wetland insects. What I found is that insects from these goldmine sites have mercury levels 50 times higher than insects from clean healthy wetlands. And in species like dragonflies and mayflies, which shed their skin, hatch in the water and fly away. Those adults are still keeping almost half of that mercury even after they hatch.

“So this means not only are these sites leading to mercury entering the food webs, it’s also at risk of spreading, moving with these insects as they leave the wetlands and fly to neighboring habitats.”

Read more about Leblanc’s work in this February 2020 CBC story by Frances Willick.

See also: News brief: Muskrat Falls flooding to start any day, leaving Innu and Inuit vulnerable to mercury poisoning

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