Dataset: Size Fractionated Chlorophyll Dataset
Deployment: TAN1810

Field Collection

Data was collected in the Chatham Rise section of the Southern Ocean, located east of Aotearoa New Zealand, as part of the SALPOOP (‘Salp Particle expOrt and Ocean Production’) voyage during October to November 2018. ). We conducted five Lagrangian experiments (hereafter referred to as “cycles”) that lasted four to eight days (Décima et al., 2023). There were three cycles that were sampled in SA waters (1, 2 and 5) and two cycles in ST waters (3 and 4) while salps were only present in three cycles (1, 2 and 4). Six depths were chosen to span the euphotic zone (based on chlorophyll fluorescence measured during the conductivity-temperature-depth (CTD) downcast profiles).

Size Fractionated Chlorophyll a Measurements

Samples for size fractionated chlorophyll a (SF Chla) were analyzed by first gravity filtering a sample (250 mL) through a 20 µm 47-mm polycarbonate filter, then with low vacuum pressure, filtering sequentially through a 2 µm and a 0.2 µm filter. Filters were then folded, placed in 1.5 mL cryovials and frozen (-80 °C) until analysis (Gutiérrez‐Rodríguez et al., 2020). Chla and acidified phaeopigment-a concentrations were measured (within 3 months) using ice-cold 90% acetone extraction by spectrofluorometric methods (APHA 10200 H) on a Varian Cary Eclipse fluorescence spectrophotometer (Rice et al., 2012).