Technical Note: An Autonomous Flow through Salinity and Temperature Perturbation Mesocosm System for Multi-stressor Experiments

• Main Authors: Miller, Cale, Urrutti, Pierre, Gattuso, Jean-Pierre, Comeau, Steeve, Lebrun, Anaïs, Alliouane, Samir, Schlegel, Robert, Gazeau, Frédéric
• Other Authors: Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Earth Sciences Utrecht, Universiteit Utrecht / Utrecht University Utrecht
• Format: Report
• Language: English
• Published: HAL CCSD 2023
• Subjects: [SDE]Environmental Sciences; Arctic; Svalbard; Kongsfjord*; Kongsfjorden
• Online Access: https://hal.science/hal-04240387; https://hal.science/hal-04240387/document; https://hal.science/hal-04240387/file/egusphere-2023-768.pdf; https://doi.org/10.5194/egusphere-2023-768

Abstract. The rapid environmental changes in aquatic systems as a result of anthropogenic forcings are creating a multitude of challenging conditions for organisms and communities. The need to better understand the interaction of environmental stressors now, and in the future, is fundamental to determining the response of ecosystems to these perturbations. This work describes an in situ mesocosm perturbation system that can manipulate aquatic media in a controlled setting on land. The employed system manipulated ambient water from Kongsfjorden, (Svalbard) by increasing temperature and freshening the seawater to investigate the response of mixed kelp communities to projected future Arctic conditions. This system manipulated temperature and salinity in real-time as an offset from incoming ambient seawater to conditions simulating future Arctic fjords. The system adjusted flow rates and mixing regimes of chilled, heated, ambient seawater, and freshwater, based on continuously measured conditions in a total of 12 mesocosms (1 ambient-control and 3 treatments, all in triplicates) for 54 days. System regulation was robust as median deviations from setpoint conditions were < 0.15 for both temperature (°C) and salinity across the 3 replicates per treatment. The implementation of this system has a wide range of versatility and can be deployed in a range of conditions to test single or multi-stressor conditions while maintaining natural variability.