Negative tests for microplastics a positive for marine mammals in eastern Canadian Arctic

No microplastics found in 142 examined seals

  • Feb 14, 2020
  • 336 words
  • 2 minutes
scientist in lab coat looking at microscope slide Expand Image

A good news story about microplastics? 

Researcher Madelaine Bourdages was surprised, too, when her research project involving seals from the eastern Canadian Arctic revealed no traces of microplastics in the seals’ stomachs.

Recent studies have found plastics in the digestive systems of turtles, albatross and other marine animals. Bourdages had the opportunity to find out how eastern Canadian Arctic seals were faring in these days of marine plastic pollution.

“We didn’t know what we were expecting,” says Bourdages. “We know more and more animals are interacting with plastics. In a way we were expecting to find something.”

Bourdages studied 142 seals culled by Inuit hunters between 2007 and 2019 in Arviat, Naujaat, Sanikiluaq and Iqaluit. Bird species from the same region had been found to have ingested plastic debris, but Bourdages’ study was the first to look at marine mammals in the region.

In April 2019, the seal stomachs were shipped to Carleton University, where Bourdages is completing a Master of Science in geography and environmental studies. Stomach contents were inspected under a microscope. 

The research team found primarily fish and krill. Bourdages says they were only looking for microplastics above a certain size — any smaller and the plastics would be likely to pass through the seal’s system.

According to Bourdages, finding fish and krill means the seals were eating from the middle of the water column, not from the surface or the bottom. 

“Most plastics either float or sink to the bottom, so maybe [the seals] weren’t interacting as much with the plastics,” says Bourdages.

Bourdages says any research showing that plastics aren’t having a negative effect on animals is a good thing.

“This doesn’t mean plastic pollution isn’t there, but at the same time this a good, positive result.” 

The study included ringed seals, bearded seals and a single harbour seal. There are no plans right now to continue monitoring seals from the region. 

Related: Microplastics are everywhere – even in us


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