Primary productivity

Primary production was assessed by measuring carbon incorporation (C13 stable isotope) within 1 L sample bottles paced in an incubation box. The incubation box was exposed to sunlight. Bottles were either clear bottles (for surface samples) or covered with light filters (for DCM samples) in order to reproduce in situ PAR (photosynthetic active radiation) given by the CTD sensor.

Phytoplankton pigments (eg chloroph

For phytoplanktonic pigments, seawater was filtered on GF/F 25 mm filters just after collection. Depending on the sample load, 500 ml to 1 L of water was filtered for each sample. Pigments will be measured at the laboratory (IMAGO, Brest) by high pressure liquipd chromatograhy (HPLC). Pigments are measured on 'raw samples' ('HPLC tot' without pre-filtration) and on water filtered at 20µm ('HLPC 20µ' and 'HPLC' and 'HPLC fract' for the >20µm and the <20µm size classes).

Pelagic bacteria/micro-organisms

Samples for bacterial diversity measurement by flow cytometry were kept from filtered water (<20 µm and <1 µm) in cryotubes (1.6 ml of water + 80 µl formalin) and stored in liquid nitrogen. They will be kept at -80°C during the transport to the laboratory. Bacterial communities will be counted by flux cytometry. Their diversity will be described by sequencing.

Pelagic bacteria/micro-organisms

Bacterial respiration was measured on samples taken at the same depth (surface and DCM) as for primary production assessment. Aliquots (30 ml) of filtered (<1 µm) water sample were stored in black tanks at a constant temperature (28°C) for 24 hours. Oxygen content was regularly measured (every 5 minutes) within the tanks using a dedicated oxygen sensor.

Phytoplankton

Samples for phytoplankton identification and abondance were taken by filtration of 1 L to 2 L of seawater from Niskin bottleson 5µm filters. Fliters were kept in plastic bottles with 30ml of the filtered seawater and 600 µl of lugol). They were stored in a normal freezer 4°C. All taxonomic data (phytoplankton was also sampled with a 20 µm net) will be made available on an interactive database (http://data.oreme.org/plankton/phytoplankton_home).

Phytoplankton

In addition to samples from the Rosette. Fifteen phytoplankton samples were collected using a 20 µm mesh-size phytoplankton net.

Zooplankton

Zooplankton was sampled using a bongo with two mesh-size (64 and 120 µm) and a Multinet (5 closing nets, 300 µm).

Nekton

Pelagic organisms were sampled using a micronekton trawl (body mesh: 40 mm, cod-end mesh: 10 mm)

Pelagic fish

Pelagic fish were sampled using a micronekton trawl (body mesh: 40 mm, cod-end mesh: 10 mm)

Demersal fish

Bentho-demersal communities were sampled using a bottom trawl `Rockhopper'( body mesh: 40 mm, cod-end mesh: 25 mm).

Acoustic reflection on marine organ

Multifrequency acoustic data have been continuously acquired during the survey (Stations included) using an EK60 at 38, 70, 120 and 200 kHz.

Particulate organic matter (inc POC

Particulate organic matter (POM) samples were taken by filtration on GF/F 47 mm pre-carbonized fiters. A large volume of water (up to 8 L for clear water) was filtered in order to get enough material for the determination of carbon and nitrogen stable isotopes content by mass spectrometry (at the laboratory). Filters were dried in an oven (60°C during 48h) and kept at room temperature until the isotopic measurement.

Surface drifters/drifting buoys

Five drifter provided by meteofrance have been deployed.

Current profiler (eg ADCP)

Two LADCPs RDI 300 kHz were mounted on the Rosette, one looking down (S/N 12818) and one looking up (S/N 24085). LADCP profiles were thus performed simultaneously to CTDO profiles (SBE911+). The compass of both LADCP were calibrated in the LOPS platform in February 2021.

Current profiler (eg ADCP)

ADCP data (75 kHz) have been recorded continuously during the survey (see EK60 echousounder section for problem in the acquisition). Settings have been adjusted to the bottom depth (< and > 150 m deep); see below for the configurations.

Other physical oceanographic meas.

To characterise highly turbulent environments down to 1000 m depth we used a vertical microstructure profiler (VMP). The turbulence measurement (resolution: ~2 mm) is used to deduce the rate of energy dissipation within water masses.

Other physical oceanographic meas.

A Slocum Crate Glider has been deployed. This glider is equipped of physical (pressure, conductivity, temperature) and biogeochemical (fluorescence, oxygen, Fluorescence Dissolved Organic Matter, optical backscattering) sensors. The objective of the Glider is to sample the hydrography off the continental shelf in the propagation path of internal waves.

Other physical oceanographic meas.

Installation of two moorings fitted with with ADCP and CTDs. One of the two moorings has broken.

Water bottle stations

CTD stations

A rosette equiped with 11 Niskin bottles, a CTDO SBE911+ and two LADCP have been used during the hydrological profiles to sample water down to 1000 m deep.

Subsurface meas. underway (T,S)

Termperature and salinity data have been acquired continusly using a thermosalinograph SBE21.

Optics (eg underwater light levels)

A variety of optical instruments were mounted on an optical grape equipped with its own CTD for the acquisition of: At the sea surface: particle size distribution (PSD) and particles scattering properties; Along vertical profile: quantitative and qualitative data on the particulate (PSD, zooplankton and particles scattering properties), coloured dissolved matter distribution, total chlorophyll_a and the specific biomass of major phytoplankton groups, and the underwater light field.

Oxygen

Oxygen samples were taken at different depth levels, at each station according to classical methods. The sampling strategy was designed to provide in situ reference data for the CTD sensor calibration. Samples were analysed onboard.

Oxygen

Samples for O18 were stored in 30 ml brown glass bottles and stored at room temperature. Six profiles for O18 measurements have been taken during the cruise in different water mass types (open ocean stations, coastal stations, Amazone plume stations).

Phosphate

Nutrients samples were collected at each sampling depth in 30 ml Nalgen vials and stabelised in an oven at 80°C during 2h30 (pasteurization).

Nitrate

Nutrients samples were collected at each sampling depth in 30 ml Nalgen vials and stabelised in an oven at 80°C during 2h30 (pasteurization).

Nitrite

Nutrients samples were collected at each sampling depth in 30 ml Nalgen vials and stabelised in an oven at 80°C during 2h30 (pasteurization).

Silicate

Nutrients samples were collected at each sampling depth in 30 ml Nalgen vials and stabelised in an oven at 80°C during 2h30 (pasteurization).

Carbon dioxide

Samples for CO2 measurements (DIC and AT) were stored in 500 ml glass bottles and poisonned with 300 µl HgCl2. They were kept at room temperature until analysis at the laboratory.

Carbon dioxide

Samples for CO2 measurements (DIC and AT) were stored in 500 ml glass bottles and poisonned with 300 µl HgCl2. They were kept at room temperature until analysis at the laboratory.