Tesan-Onrubia J. A. auteur aut IRD Tedetti Marc auteur aut IRD Carlotti F. auteur aut IRD Tenaille M. auteur aut IRD Guilloux L. auteur aut IRD Pagano Marc auteur aut IRD Lebreton B. auteur aut IRD Guillou G. auteur aut IRD Fierro-Gonzalez P. auteur aut IRD Guigue Catherine auteur aut IRD Chifflet Sandrine auteur aut IRD Garcia T. auteur aut IRD Boudriga I. auteur aut IRD Belhassen M. auteur aut IRD Zouari A. B. auteur aut IRD Banaru D. auteur aut IRD text journalArticle eng text/pdf born digital access Plankton represents the main source of carbon in marine ecosystems and is consequently an important gateway for contaminants into the marine food webs. During the MERITE- HIPPOCAMPE campaign in the Mediterranean Sea (April-May 2019), plankton was sampled from pumping and net tows at 10 stations from the French coast to the Gulf of Gabe`s (Tunisia) to obtain different size fractions in contrasted regions. This study combines various approaches, including biochemical analyses, analyses of stable isotope ratios (813C, 815N), cytometry analyses and mixing models (MixSiar) on size-fractions of phyto-and zooplankton from 0.7 to >2000 mu m. Pico-and nanoplankton represented a large energetic resource at the base of pelagic food webs. Proteins, lipids, and stable isotope ratios increased with size in zooplankton and were higher than in phytoplankton. Stable isotope ratios suggest different sources of carbon and nutrients at the base of the planktonic food webs depending on the coast and the offshore area. In addition, a link between productivity and trophic pathways was shown, with high trophic levels and low zooplankton biomass recorded in the offshore area. The results of our study highlight spatial variations of the trophic structure within the plankton size-fractions and will contribute to assess the role of the plankton as a biological pump of contaminants. specialized Phytoplankton Zooplankton 813C 815N Plankton trophic structure Contaminants MEDITERRANEE 038 034 189 114787 [16 ] 2023 0025-326X https://www.documentation.ird.fr/hor/fdi:010087517 10.1016/j.marpolbul.2023.114787 0025-326X [F B010087517] https://www.documentation.ird.fr/hor/fdi:010087517 https://www.documentation.ird.fr/intranet/publi/2023-05/010087517.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2023-05-12 2025-02-24 fdi:010087517 fre