Between Northeastern Tides

Finding climate clues beneath Arctic waves

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How can we better understand the complex ocean dynamics in places highly sensitive to climate change?

Jessica Gould, PhD Candidate at Northeastern’s Marine Science Center

PhD Candidate Jess Gould seeks to answer this question by investigating the potential for reconstructing climate history from algal growth in the Canadian Arctic – and she has just earned a prestigious research award to do it.  Gould, an Ontario native, has just received the Alexander Graham Bell Canada Graduate Scholarship, the highest tier of award from the Natural Sciences and Engineering Research Council of Canada.  This program will combine in situ data collected in Arctic Bay, Nunavut with the research capabilities of the Ries Lab at Northeastern University’s Marine Science Center to monitor the growth of the long-lived coralline algal species Clathromorphum compactum.

Gould travelled to Arctic Bay in Nunavut, Canada in September 2019 to set up the in situ coralline algae monitoring experiment. She spent 3 weeks onboard the RV Vagabond, a private research vessel, working with the ship’s captain Eric Brossier to find and collect live coralline algae specimens from the seafloor. C. compactum is a long-lived calcium carbonate producing algae, growing for 200-700 years and producing annual layers that can be counted, dated, and chemically analyzed to reconstruct past environmental conditions. Gould’s research team includes Dr. Jochen Halfar of University of Toronto, one of the world’s experts in marine coralline algae.

After Gould and Brossier’s successful sampling of C. compactum,  the algae were stained with a special non-hazardous dye, marking the initiation of in situ experimental growth, then set up for re-deployment to the seafloor where they were originally collected. Sensors deployed immediately adjacent to the specimens are monitoring in situ environmental conditions, such as temperature, conductivity (salinity), light availability (proxy for sea-ice cover), and pH, which will be correlated to the growth rates and elemental compositions of the coralline algae skeletons over the course of the experiment.

Gould will use the state-of-the-art Laser Ablation Inductively Coupled Plasma Mass Spectrometer (LA-ICPMS) in the Ries Lab at Northeastern University to measure a suite of trace elements in the algal specimens. In addition to the proposed in situ monitoring study, live specimens have also been collected from Arctic Bay, NU and transported back to the Ries Laboratory Seawater Experimental Tank Array for a controlled laboratory experiments.

Gould and her collaborators hope this work will provide valuable environmental reconstructions that will contextualize present and future changes in this region, expanding the network of oceanographic reconstructions for the Canadian Arctic and Subarctic and improving our understanding of ocean dynamics in a region that is particularly sensitive to climate change.

Arctic Bay, Nunavut (Photo: Eric Brossier)
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