More than a garbage truck’s worth of plastic enters the ocean every minute.

 

So, understanding how plastic moves through the ocean and where it ends up is critical for determining the harm it inflicts on wildlife and humans.

 

Dr. Alice (Xia) Zhu, one of Memorial University’s newest Banting post-doctoral scholars, has begun her research on the fate of plastic in our oceans.

 

The Banting Post-doctoral Fellowship, one of Canada’s most prestigious research awards, not only supports Dr. Zhu’s research but also highlights the importance of conservation and climate change action.

 

The knowledge gap

 

Dr. Zhu, who is based in Memorial's Department of Ocean Sciences, Faculty of Science, is researching microplastics in the Atlantic Ocean.

 

Her goal is to understand how quickly microplastics sink to the ocean bottom to help determine the risk that plastic poses to marine biota.

 

The fate of plastic pollution in the ocean is not well understood.

 

There is a significant knowledge gap when estimating how much plastic exists within marine animals globally, making it difficult to reconcile the fate of plastic in the global ocean.

 

Ten ping pong balls

 

Dr. Zhu’s recent findings from a collaboration with University of Toronto and Scripps Institution of Oceanography researchers are shedding light on how sea turtles can act as "reservoirs" or resting places of plastic pollution.

According to Dr. Zhu and her collaborators, a single female green sea turtle can contain up to 26.4 g of plastic: the equivalent mass of 10 ping pong balls.

 

They estimate that female green turtles contain 5.6-6.4 tonnes of plastic in their gastrointestinal tracts globally, which is approximately a garbage truck’s worth of plastic pollution.

This reservoir of plastic has implications for sea turtle health, as we know that plastic ingestion by turtles can lead to emaciation, starvation and perforation of the gut lining.

 

They also found that leatherback turtles have the greatest tendency to ingest plastic.

“Sea turtles are becoming storage places for our waste,” said Zhu. “This is not a reality we should willingly accept. Urgent action is needed to reduce the amount of plastic entering the ocean and protect sea turtles from the worst consequences of plastic pollution.”

 

Geographic, socio-economic and ecological

 

The study represents one of the first attempts to understand which sea turtle species are most prone to plastic ingestion and provides the first estimate of a global marine animal reservoir of plastic.

Along with providing a global plastic reservoir estimate, the researchers also identified that geographic, socio-economic and ecological factors significantly predict how much plastic is found within sea turtle gastrointestinal tracts.