@article{fdi:010071051, title = {{T}rophic pathways of phytoplankton size classes through the zooplankton food web over the spring transition period in the north-west {M}editerranean {S}ea}, author = {{H}unt, {B}. {P}. {V}. and {C}arlotti, {F}. and {D}onoso, {K}. and {P}agano, {M}arc and {D}'{O}rtenzio, {F}. and {T}aillandier, {V}. and {C}onan, {P}.}, editor = {}, language = {{ENG}}, abstract = {{K}nowledge of the relative contributions of phytoplankton size classes to zooplankton biomass is necessary to understand food-web functioning and response to climate change. {D}uring the {D}eep {W}ater formation {E}xperiment ({DEWEX}), conducted in the north-west {M}editerranean {S}ea in winter ({F}ebruary) and spring ({A}pril) of 2013, we investigated phytoplankton-zooplankton trophic links in contrasting oligotrophic and eutrophic conditions. {S}ize fractionated particulate matter (pico-{POM}, nano-{POM}, and micro-{POM}) and zooplankton (64 to >4000 mu m) composition and carbon and nitrogen stable isotope ratios were measured inside and outside the nutrient-rich deep convection zone in the central {L}iguro-{P}rovencal basin. {I}n winter, phytoplankton biomass was low (0.28 mg m(-3)) and evenly spread among picophytoplankton, nanophytoplankton, and microphytoplankton. {U}sing an isotope mixing model, we estimated average contributions to zooplankton biomass by pico-{POM}, nano-{POM}, and micro-{POM} of 28, 59, and 15%, respectively. {I}n spring, the nutrient poor region outside the convection zone had low phytoplankton biomass (0.58 mg m(-3)) and was dominated by pico/nanophytoplankton. {E}stimated average contributions to zooplankton biomass by pico-{POM}, nano-{POM}, and micro-{POM} were 64, 28 and 10%, respectively, although the model did not differentiate well between pico-{POM} and nano-{POM} in this region. {I}n the deep convection zone, spring phytoplankton biomass was high (1.34 mg m(-3)) and dominated by micro/nano phytoplankton. {E}stimated average contributions to zooplankton biomass by pico-{POM}, nano-{POM}, and micro-{POM} were 42, 42, and 20%, respectively, indicating that a large part of the microphytoplankton biomass may have remained ungrazed.}, keywords = {zooplankton ; isotopes ; food web ; phytoplankton ; trophic pathways ; {MEDITERRANEE}}, booktitle = {}, journal = {{J}ournal of {G}eophysical {R}esearch : {O}ceans}, volume = {122}, numero = {8}, pages = {6309--6324}, ISSN = {2169-9275}, year = {2017}, DOI = {10.1002/2016jc012658}, URL = {https://www.documentation.ird.fr/hor/fdi:010071051}, }