Invasive green crab at Keji seaside could soon become biodegradable plastic

Invasive green crab at Keji seaside could soon become biodegradable plastic

February 18, 2020
Marcia González

Invasive green crabs that have caused major problems for native species such as eelgrass at Nova Scotia’s Kejimkujik National Park Seaside could, ironically, be the latest solution to reducing plastic pollution in the ocean

Parks Canada has teamed up with a McGill University professor to find a way to turn the shells of the pesky crabs into a biodegradable plastic that could be used to make cutlery, cups or plates.

Crabs harvested from the park just south of Liverpool, Nova Scotia, will be shipped this spring to Montreal, where Audrey Moores has developed a non-toxic way to transform a polymer naturally found in crustacean shells into a hard, opaque plastic-like material.

“What we know is that if we take regular crab shells, shrimp shells, lobster shells, we have very good results, so we’re fairly confident that the green crab should not be different,” said Moores.

Unlike regular plastic, the material that Moores is left with will degrade in the ocean. But more research is needed to find out just how long that process will take, she Moores.

It’s exciting research for Gabrielle Beaulieu, project manager for the eelgrass conservation restoration project at Kejimkujik Seaside. She stumbled across it recently and wondered if it could help in Kejimkujik’s decades-long battle with green crabs.

“Invasive species may be detrimental to the ecosystem, however there’s always surprise solutions that we have to be open to,” Beaulieu said.

European green crabs have been wreaking havoc on eelgrass and soft-shell clams at the park since the 1980s. They first arrived in North America in the ballast water of ships from Europe in the 1800s and have been on the move due to warming oceans.

There are now just a handful of spots in Atlantic Canada without green crabs, Beaulieu noted. “If we can make this invasive species come full circle as a solution to the plastic pollution issue that all the oceans are facing today, I really think that’s going to be such a great and innovative way to figure out the invasive species problem,” she added.

Thanks to initiatives such as the ecotourism campaign Gone Crabbin’, two million green crabs have been hauled up at Kejimkujik Seaside Park since 2010, said Beaulieu.

Now, there’s a year-round place for them to go.

“We’re really hoping that this project demonstrates an innovative new way of dealing with invasive species,” she said. “Certainly, as climate change is upon us, there may be more introductions of marine species that we still know nothing about.”

The key to creating biodegradable plastic from green crabs lies in chitin, one of the main components in crustacean and insect shells.

Moores, an associate professor in McGill’s chemistry department, crushes the shells to get to the chitin. She then uses a special method she’s developed to transform the polymer into a material that will withstand water.

“So now you can make a cup out of it that will hold the water because the cup itself is not going to be dissolved by the water,” she said.

Right now, the plastic material that’s created is hard like glass, but Moores said her team is hoping to find a way to make it bendable so it could be formed into disposable cutlery and other single-use items.

Plastic Free World Conference & Expo 2020 will take place at Cologne Messe, Germany, on Tuesday 16 June and Wednesday 17 June. To register for this highly focused, solutions-driven event, please click here. For sponsorship and exhibition opportunities, please email

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