Elemental composition and organic content of the salp Soestia zonaria in the temperate Northeast Atlantic and the Southwest Pacific over the Chatham Rise

Although the oceanic widespread pelagic tunicate Soestia zonaria has been studied for more than a century, little ecological information exists. Soestia primarily occurs in tropical to warm-temperate regions. Soestia specimens were collected in 2008 and 2021 during two research expeditions (EXPORTS cruise to the Northeast Atlantic and TAN0806 over the Chatham Rise, New Zealand) using MOCNESS-1 net and large midwater trawl with maximum sampling depths of 1000 m. In total, 140 Soestia specimens (oral-atrial length: 7–54 mm) were analysed for biomass parameters (wet weight, dry weight, ash-free dry weight, water content, organic content) and stoichiometry (carbon and nitrogen content, carbon-to-nitrogen ratio).