New research shows “neonic” pesticides damage ocean ecosystems

Cottage on the ocean in Victoria BC MehmetO/shutterstock

Neonicotinoids, or neonics for short, are the most widely used type of pesticides in the world. They are also implicated in the global decline in pollinator species, including bee colony collapse disorder.

Seeds of common cash crops, including corn and soybeans, are coated in the pesticide, and the neonics become embedded in the plants as they grow. They are a neurotoxin in insects and while they were initially viewed as a relatively safe option since they didn’t seem to harm mammals, other recent studies have in fact found they also may impact mammals, including white-tailed deer.

“Their function is to kill insects and they do that very well, but without distinction,” says Lisa Gue, senior researcher and analyst – science and policy for the David Suzuki Foundation.

In February, researchers from the US National Oceanic and Atmospheric Administration presented a report showing that neonics also had damaging effects on coral reefs and aquatic creatures that inhabit those habitats. The study looked specifically at imidacloprid, one of the most widely used pesticides in the world, and found that it had damaging effects on coral and small shrimp-like amphipods at concentrations in the parts per billion levels, and fatal consequences in the parts per million.

“It’s further evidence of the unintended consequences” of the widespread use of these pesticides, says Gue.

This recent study is not the first time that water-soluble neonics have been implicated in aquatic ecosystems. In fact, cottagers will be interested to learn that concern was raised about the impacts on freshwater habitats more than 25 years ago. Back in 1993, shortly after local farmers started using imidacloprid around freshwater Lake Shinji in Japan, populations of crustaceans and zooplankton, important species at the base of the lake’s food chain plummeted. By the following year, eel and smelt populations had also crashed and have yet to fully recover.

Increasing evidence of the harm to a wide array of non-targeted species led the European Union to introduce a partial ban on the use of the three most common neonics, including imidacloprid, in 2013. After further study, the EU completely banned the three neonics in 2018.

In 2015, Ontario became the first North American jurisdiction to restrict the use and sale of neonics. Unfortunately, the current provincial government’s proposed Bill 132, the “Better for People, Smarter for Business Act” will water down those restrictions, by removing the required reporting of treated seed sales in the province.

Meanwhile, the federal Pest Management Regulatory Agency has yet to restrict or prohibit neonic use at a national level. “The federal regulator needs to step up to the plate,” says Gue.

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