media release

Research helps oysters grow shells

October 10, 2013

Marianne Meadahl, PAMR, 778.782.9017;


Carbon dioxide emissions from burning fossil fuels are rapidly acidifying the Earth’s oceans. Scientists predict that by the end of this century, ocean water could be five times more acidic than in pre-industrial times.

It’s particularly bad news for shellfish, and shellfish farmers. “So much acidity is playing havoc with shellfish larvae’s ability to grow their shells because the ocean is losing the carbonate ions that larvae need to build their shells,” says Carolyn Duckham, a Simon Fraser University environmental sciences graduand.

She has spent the past two years researching whether hydrated lime, which is a basic chemical produced from heating limestone, could be added to shellfish hatcheries’ closed seawater systems to neutralize the acid and replace the missing carbonate ions.

She worked with Taylor Shellfish Farms, a Washington-based hatchery that was experiencing large die-offs of shellfish larvae.

The farm supplied the oysters, and Duckham spawned them in seawater tanks in SFU’s Climate, Oceans and Paleo-Environments lab in the School of Resource and Environmental Management.

She found that the hydrated lime, which is cheap, plentiful and reacts quickly in seawater, did reverse the acidification and enhanced shellfish larvae growth after two weeks of development.

“Actually liming the ocean is not a possibility,” she says, “but in terms of helping the shellfish industry it could be beneficial.”

Duckham was working as an aquatic biologist at Rescan Environmental Services Inc. for two-and-a-half years before she returned to SFU to earn her Master of Resource Management (MRM).

“At Rescan, I had a BSc whereas many others had their MSc. I knew the BSc was limiting,” she says.

But now that she’s earned her MRM, Duckham isn’t immediately returning to industry.

Instead, she has just begun a PhD program at UBC, where she is continuing her research with the second instalment of a $100,000 Natural Sciences and Engineering Research Council scholarship—one of the council’s top awards.

“I hope that afterwards I can do a post-doc and continue in research,” she says. “The impact of climate change on the ocean is quite complicated. It’s so hard to predict what will happen. That’s what really drives me,” she says. “And, I have a lot of fun doing it.”

Simon Fraser University is Canada's top-ranked comprehensive university and one of the top 50 universities in the world under 50 years old. With campuses in Vancouver, Burnaby and Surrey, B.C., SFU engages actively with the community in its research and teaching, delivers almost 150 programs to more than 30,000 students, and has more than 120,000 alumni in 130 countries.


Simon Fraser University: Engaging Students. Engaging Research. Engaging Communities.

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