A Memorial University researcher is unlocking the secrets of the global ocean’s carbon cycle.

The ocean absorbs 25% of the carbon emissions that result from human activities and plays a critical role in maintaining our climate. The ocean’s absorption includes taking in carbon dioxide from the air, meaning that it helps us manage the most concerning carbon form associated with human activities.

The global ocean holds approximately 50 times more carbon than the atmosphere. In the ocean, 97% of the organic carbon that’s present is dissolved. It’s referred to as dissolved organic matter (DOM). For perspective, the DOM accounts for 32 times as much carbon as the amount found in all living organisms in the ocean. Interestingly, very little is known about the individual chemicals that make up DOM, so it’s challenging to determine its role in the global carbon cycle.

That’s where Dr. Heather Reader comes in. In June 2024, Dr. Reader was renewed as Memorial’s Tier 2 Canada Research Chair in Chemistry of the Ocean and Atmosphere.

DOM is chemically very complex. Additionally, the way it functions varies significantly in different marine ecosystems. Applying statistical approaches to complicated chemical datasets, Dr. Reader is developing smarter ways of tracing where DOM comes from, understanding how it has interacted with the marine ecosystems, and determining where it will end up in the future. From coastal systems to the open ocean, she uses novel combinations of chemical analysis to unlock the secrets of DOM and the role it plays in the ocean’s carbon cycle.

“DOM is very interesting in this region,” Dr. Reader said of the habitat she’s studying on Canada’s east coast. “Here in Newfoundland and Labrador, we have high DOM concentrations both in rivers and the coastal ocean. In the open ocean, we have interesting biological and physical processes in this region of the Northwest Atlantic that contribute to the global carbon cycle.”

“I want to know where the DOM comes from and where it goes to determine the role it plays in carbon cycling and carbon sequestration in the ocean,” she added.

New analysis methods are needed to assess the chemical nature of this carbon and to allow for better monitoring of shifts in marine ecosystems. Once available, this technology will lead to a more complete understanding of the part that the oceans play in our complex physical world.

In the course of her work, Dr. Reader collaborates with fellow Canada Research Chair Dr. Uta Passow, Department of Ocean Sciences, who is researching the Labrador Sea biological carbon pump. 

A large part of Dr. Reader’s research takes place at sea, collecting samples and performing experiments. She and her students spent 3 weeks on the Labrador Sea last year collecting DOM present there.

“Luckily, we had 14 straight days of good weather and managed to get every planned sample. Now, we have 300–400 samples for optical analysis and organic carbon analysis. We are heading back in May this year to investigate the spring bloom and its impact on carbon cycling.”

After a period of cancellations and deferrals due to the COVID-19 pandemic, Dr. Reader and her team spent more time at sea in 2024 than over the previous 4 years. They also participated in cruises in the Pacific Ocean and Baffin Bay, cataloguing more samples for further analysis. Dr. Reader notes that the designation of Canada Research Chair provides more research opportunities, wider recognition for Memorial, and a boost for the university’s academic reputation.

“The program is a great opportunity, and I’m very thankful the Chair was renewed. It means the hard work that me and my students have put in has been recognized by our peers,” she said.

Dr. Reader is passionate about supporting and elevating her students’ successes and ensuring equitable representation in the employment of Memorial’s Undergraduate Career Experience Program students. She currently supervises 7 graduate students and 2 undergraduate students.

She says it’s exciting to see the students “doing their thing, writing their thesis” and going on to their own careers.

Dr. Reader also wants to use her position to elevate Memorial’s research reputation.

“There are a number of Canada Research Chairs and researchers at the university that are doing incredible work. I can help shine a spotlight on not just my work, but everyone’s.”

The Canada Research Chairs Program stands at the centre of a national strategy to make Canada one of the world’s top countries in research and development. The program is a tri-agency initiative of the Social Sciences and Humanities Research Council, the Natural Sciences and Engineering Research Council and the Canadian Institutes of Health Research. It is administered by the Tri-agency Institutional Programs Secretariat.

This article was adapted and republished with permission from Memorial University.