Two Northeast Fisheries Science Center scientists visited their Canadian counterparts to measure oxygen consumption in baby sea scallops exposed to ocean temperatures and pH levels expected in the future.
Dr. Gurney-Smith (back) picking scallop larvae under the microscope while Katyanne Shoemaker (front) loads larvae into the respiration chamber plate. Credit: NOAA Fisheries/Shannon Meseck
In September 2024, my colleague Shannon Meseck and I took a road trip up north to Canada, to visit a research lab in St. Andrews, New Brunswick. The St. Andrews Biological Station is a part of Fisheries and Oceans Canada, the Canadian equivalent to NOAA Fisheries. Though the oldest of Canada’s Atlantic research facilities, the lab features state-of-the-art seawater systems with capacity to do climate and aquatic research.
This project was a transboundary collaboration with climate scientist Helen Gurney-Smith to study climate change stressors on Atlantic sea scallop larvae. It was funded by the NOAA Ocean Acidification Program. The larval period, typically the first 3 weeks of a sea scallop’s life, is particularly challenging for bivalve shellfish because they are planktonic, or free-floating in the water column. During this period, larvae are subject to heavy predation and are transported through ocean currents. The water they are exposed to is constantly changing with environmental conditions, and pulses of warm and/or low pH water are becoming more common with climate change.
Two-week-old sea scallop larvae. The width of each of these planktonic shellfish larvae is about the width of a human hair. Credit: NOAA Fisheries/Katyanne Shoemaker
One way we can test how larvae respond to changes in environmental conditions is by measuring their respiration rate. As with all animals, sea scallops breathe oxygen and release carbon dioxide. The oxygen they breathe is dissolved in seawater, and we can measure the drop in the oxygen concentration of that water over time with specialized equipment known as respiration chambers. Changes in respiration rate indicate physiological stress. We hypothesized that respiration rate may change when sea scallop larvae are exposed to non-ideal seawater conditions.
While in Canada, we performed three experiments to answer three questions:
- How do larvae raised in current conditions respond to sudden changes in pH?
- How do larvae raised in current conditions respond to sudden changes in temperature?
- How do larvae acclimated to different pH water respond to heat wave conditions
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The next steps of this collaboration are to analyze the data and see how the scallop larvae responded to the different treatments. The temperatures and pH levels we chose for this experiment represent ocean conditions expected in the near and distant future. The results will also serve as a snapshot of how larval sea scallops may respond to sudden changes that are becoming more and more frequent, including marine heatwaves that create a pulse of warm water to which the animals must adjust.
As a part of this international collaboration, some of Dr. Gurney-Smith’s team will visit us at the Milford Lab next year to help with our ongoing surfclam ocean acidification work. They will introduce us to technologies they use in the Canadian lab that we can apply to larval Atlantic surfclams here in Milford.
NOAA Fisheries, 14 November 2024. Full article.
