Contamination of planktonic food webs in the Mediterranean Sea: Setting the frame for the MERITE-HIPPOCAMPE oceanographic cruise (spring 2019)

Spatial variations of biochemical content and stable isotope ratios of size-fractionated plankton in the Mediterranean Sea (MERITE-HIPPOCAMPE campaign)

“…1, Table S1). Phytoplankton and zooplankton were sampled at each station at the CML, during spring bloom (April to May), when maximum primary and secondary production occurs (Liénart et al, 2018;Tedetti et al, 2023).…”

“…The MultiNet was then returned to the water. This operation was repeated several times to get sufficient amounts of plankton for all possible further contaminant content analyses (Tedetti et al, 2023). In the clean onboard container lab, plankton collected in PFA bottles was then size-fractionated through a column of five stainless steel sieves (60, 200, 500, 1000 and 2000 µm mesh-size) by wet-sieving with seawater previously filtered onto GF/F filters and stored in stainless steel jerrycans to obtain the following size-fractions: 60-200, 200-500, 500-1000, 1000-2000 and > 2000 µm. Samples were stored in pre-combusted (450 °C, 6 h) Pyrex bottles, conserved at -20 °C and freeze-dried.…”

“…The effect of size-fractions and geographical area on the SPMDW, PlanktonDW, POC, PON, C/N, carbon biomass of phytoplankton, biochemical composition, energy content, isotopic composition and trophic levels were tested by means of one-way ANOVA or non-parametric Kruskal-Wallis tests after testing for normality and homogeneity of variances, followed by appropriate paired comparison tests, using the software Statistica 12. Spearman's rank order correlation tests were used to assess the significance of the correlations between our results and some environmental variables (Tedetti et al, 2023).…”

“…Besides its central role in the functioning of marine ecosystems, plankton is now recognized as a key gateway of inorganic and organic contaminants into the marine food web (Tao et al, 2018;Chouvelon et al, 2019;Tedetti et al, 2023). Phytoplankton is exposed to contaminants via water.…”

“…Champalbert (1996) highlighted spatial differences in the zooplankton diversity and biomass, with a lower diversity and a higher biomass in coastal waters relative to offshore areas. The Mediterranean Sea is also strongly exposed to chemical contamination due to the intensive human activities in the bordering countries, its semi-closed status that limits the dilution of contaminants, and the relatively short ventilation and residence times its waters (Durrieu de Madron et al, 2011;Tedetti et al, 2023).…”