Water temperature, salinity, and others collected by CTD from the passenger ship LE COMMANDANT CHARCOT in Northwestern Passages, Northwest Atlantic Ocean (limit-40 W), and North Pacific Ocean from 2023-09-12 to 2023-10-09 (NCEI Accession 0294335)

This dataset contains water temperature, salinity, and others collected by CTD from LE COMMANDANT CHARCOT in Northwestern Passages, Northwest Atlantic Ocean, and North Pacific Ocean. Due to global warming, the Arctic is experiencing rising temperatures resulting in the thawing of permafrost soil and an increase of glacial mass loss. These processes are expected to increase the flux of inorganic and organic nutrients into coastal ecosystems, reduce the salinity of surface waters, and change light conditions of the water column. Together, these environmental changes can affect the composition and distribution of the plankton community, likely favoring harmful algal species and associated phycotoxins. These harmful algae can impact public health and the economy of areas dependent on arctic resources. The aim of this project is to establish a baseline of the phytoplankton community composition in two understudied Arctic systems, heavily impacted by global warming: fjord systems with melting glaciers and coastal ecosystems impacted by permafrost thawing. To that end, oceanographic parameters (e.g., dissolved nutrients and organic carbon) and vitamins that shape the phytoplankton community, as well as dissolved and particulate phycotoxins, will be measured. Particulate phycotoxins will be studied both at the producer level (phytoplankton) and at the zooplankton level (phytoplankton natural predators), to address transference and conversion of phycotoxins in the first levels of the trophic web. Additionally, onboard bottle incubation experiments will be carried out to determine which nutrients (nitrogen, phosphorus, silicate, vitamins) may limit primary production and shape the phytoplankton community composition. Results obtained from this project will highlight possible plankton community shifts and their drivers and help predict future consequences of global warming in these two sensitive and changing arctic ecosystems. Data are in CSV format. This dataset is MSR/RATS cruise U2023-011 (Ponant RN035) as part of the World data center for oceanography.