Hunt B. P. V., Carlotti F., Donoso K., Pagano Marc, D'Ortenzio F., Taillandier V., Conan P. (2017). Trophic pathways of phytoplankton size classes through the zooplankton food web over the spring transition period in the north-west Mediterranean Sea. Journal of Geophysical Research : Oceans, 122 (8), p. 6309-6324. ISSN 2169-9275.
Titre du document
Trophic pathways of phytoplankton size classes through the zooplankton food web over the spring transition period in the north-west Mediterranean Sea
Année de publication
2017
Auteurs
Hunt B. P. V., Carlotti F., Donoso K., Pagano Marc, D'Ortenzio F., Taillandier V., Conan P.
Source
Journal of Geophysical Research : Oceans, 2017,
122 (8), p. 6309-6324 ISSN 2169-9275
Knowledge of the relative contributions of phytoplankton size classes to zooplankton biomass is necessary to understand food-web functioning and response to climate change. During the Deep Water formation Experiment (DEWEX), conducted in the north-west Mediterranean Sea in winter (February) and spring (April) of 2013, we investigated phytoplankton-zooplankton trophic links in contrasting oligotrophic and eutrophic conditions. Size 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 Liguro-Provencal basin. In winter, phytoplankton biomass was low (0.28 mg m(-3)) and evenly spread among picophytoplankton, nanophytoplankton, and microphytoplankton. Using 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. In spring, the nutrient poor region outside the convection zone had low phytoplankton biomass (0.58 mg m(-3)) and was dominated by pico/nanophytoplankton. Estimated 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. In the deep convection zone, spring phytoplankton biomass was high (1.34 mg m(-3)) and dominated by micro/nano phytoplankton. Estimated 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.
Plan de classement
Ecologie, systèmes aquatiques [036]
Description Géographique
MEDITERRANEE
Localisation
Fonds IRD [F B010071051]
Identifiant IRD
fdi:010071051
