Our project focuses on studying the intermediate trophic levels of the pelagic ecosystem in New Caledonia, i.e.; zooplankton and micronekton. These components are situated at the interface between physical-chemical forcing, which greatly determines their distribution and abundance, and the exploited fisheries resources, tuna in particular, whose diet they form. We proposed two multidisciplinary cruises to acquire physical-chemical data and data on phytoplankton, zooplankton and micronekton, at sea. The physical-chemical and primary production parameters measured were: temperature, salinity, oxygen, fluorimetry, turbidity, light, currents, nutrients, photosynthetic pigments, phytoplankton abundance and carbon assimilation (primary production). Secondary production (zooplankton, micronekton) is characterized using acoustics (TAPS acoustic profiler, S-ADCP and L-ADCP current meters, SIMRAD multi-frequency sounder) and sampling with zooplankton and micronekton nets. In addition, these cruises are complemented by modelling which integrates all the parameters measured. The goal in the project's framework is to improve our understanding about the distribution and behaviour of tuna's prey to ultimately better understand the tuna-environment relationship in the New Caledonian EEZ. This is related to the Nectalis project.