Present and future impacts of ocean acidification on the American lobster in the Gulf of St. Lawrence

• Main Authors: Diane, L., Starr, M., Dumas, J., Chassé, J., Calosi, P., Delisle, D., Mei, Z., Perrie, W., Azetsu-Scott, K., Carrier-Belleau, C., Gurney-Smith, H., Rousseau, S., Long, Z.
• Format: Conference Object
• Language: English
• Published: 2023
• Subjects: Arctic; Ocean acidification
• Online Access: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5021904

The Gulf of St. Lawrence is a semi-enclosed system that is subject to large freshwater runoff and is strongly influenced by oceanic water originating from the Arctic and Atlantic Oceans. It is also characterised by the presence of deep channels whose deep waters (>200 m) are poorly ventilated. The variable topography and drivers lead to large temporal and spatial variability of biogeochemical conditions. Different regions, but particularly deep ones, show important deoxygenation, changes in carbonate system metrics, and warming in recent decades. These trends are also projected to continue in the future with an expansion of the areas presenting critical ocean acidification (OA) conditions for the health of some commercial species. In this study we describe the current state and variability of the carbonate system and how it impacts different traits of the American lobster (Homarus americanus). In order to determine which carbonate system parameters are detrimental and at which level to different traits and stages of this species, we first conducted an extensive literature review and synthesis study. A threshold analysis using broken-line regression models was then performed on the data. We used projections of OA conditions obtained from a regional downscaling system to determine the vulnerability of the American lobster to ongoing OA in the Gulf of St. Lawrence. This project is part of the Ocean Acidification Research for Sustainability program of the Ocean Decade.