Dichlorodiphenyltrichloroethane (DDT), a pesticide banned decades ago in Canada, is still causing problems in New Brunswick’s freshwater lakes.
New research from Mount Allison University reveals its lasting impact on fish populations in the province.
Led by Dr. Josh Kurek, associate professor at Mount Allison University, the study reveals troubling levels of lingering DDT contamination in Brook Trout.
These fish contain concentrations of the pesticide up to 10 times higher than ecological safety thresholds—levels where harmful effects on aquatic life tend to occur.
The study also highlighted the critical role Brook Trout play in New Brunswick’s aquatic ecosystems.
It notes that over 50,000 recreational anglers pursue this species annually across the province.
It further identifies that New Brunswick’s history with DDT use included one of the largest aerial spray programs in North America, with more than 5.7 million kilograms sprayed between 1952 and 1968 to control spruce budworm.
The findings raise concerns not only for environmental health but also for communities that rely on these fish as a food source.
The research points to how DDT has remained in lake sediments for decades and continues to persist in aquatic ecosystems.
According to the study, these sediments are a key source of contamination, with DDT accumulating in aquatic insects that are part of the Brook Trout’s diet.
“Our research sheds light on the lasting legacy of DDT pollution and reminds us how historical pesticide use continues to impact ecosystems and potentially public health today,” Kurek said in a statement.
The study emphasizes the need for increased awareness around contamination in wild food sources like fish and calls for further evaluation of long-term environmental risks from chemical treatments.
Mount Allison University’s research team hopes their findings will spark dialogue about how historical decisions shape the environmental challenges faced today.
