Coccolithophore fluxes were investigated over a one-year period at two sites of the Subantarctic Zone in the Australian and New Zealand Sectors of the Southern Ocean. The samples from the Australian SAZ were retrieved at the SOTS observatory, which lies in the SAZ (near 47°S, 142°E), approximately 500 km south west of Tasmania. SOTS was instrumented with three moored platforms: (i) a surface tower buoy that performs meteorological measurements (the Southern Ocean Flux Station - SOFS); (ii) a surface mixed layer mooring equipped with an automated water sampler) and nutrient, carbon and biological measurement sensors (the Pulse mooring); and (iii) a bottom-tethered deep sediment trap mooring that collects sinking particle fluxes for diverse biogeochemical studies (the SAZ mooring). The samples from New Zealand came from the deep-ocean SAM mooring deployed in Subantarctic waters south east of New Zealand (46°40’S, 178’ 30°E), and was equipped with sediment traps and a suite of sensors. Here, we report the coccolith sinking assemblages captured by sediment traps at ~1000, 2000 and 3800 m depth for a year from August 2011 until July 2012 at the SOTS observatory and a sediment trap at ~1500 m depth for a year from November 2009 until October 2010 at the SAM site. A description of the field experiment, sample treatment, determination of total CaCO3 content, and estimation of coccolith and coccosphere fluxes can be found in Rigual-Hernández et al. (2020a) and Rigual-Hernández et al. (2020b). Data available: two excel files (one for each station) containing sampling dates and depths, relative abundance of coccolith sinking assemblages, and coccolith, coccosphere and total CaCO3 fluxes. Detailed information of the column headings is provided below. Cup – Cup (=sample) number Depth – vertical location of the sediment trap in meters below the surface Mid-point date - Mid date of the sampling interval Duration (days) – number of days the cup was open

SAZ photos of sediment trap samples Sediment traps are cones which intercept and store falling marine particles in collection cups. The particles consist of a range of material including phytoplankton, zooplankton, faecal pellets, and dust. Each trap collects a time series of samples. The sediment traps are from deep moorings in the Southern Ocean, typically at 47S, 54S, and 61S and at around 140 degrees East. Each mooring typically has 2-3 traps between 800m and 3800m below sea-level. The samples are size fractionated into less than 1mm and greater than 1mm fractions using a 1mm sieve. Various chemical analyses and observations have been made on the less than 1mm fraction. These are photos are of greater than 1mm fraction, mainly showing 'swimmers.' Photos are mostly taken on the sieve, so the grid is 1mm for scale. Sample identification is in the file name, and also in a label in the photo. The file name format is: Typical example s02_54_800_04.jpg 1) s02: s is for SAZ. Collection season number is first year of collection season. So s02 is from SAZ 2002-2003. 2) 54: Nominal latitude. 3) 800: Nominal depth, m. 4) 04: Cup number, typically 1-21 or 1-13, single digit numbers padded with a zero to help operating systems display files in order. 5) .jpg: All photos are in jpeg format Some files have additional information at end, examples below: * FP: faecal pellet * begin and end: beginning and end of sieving process. Mostly to show faecal pellets at start that are rinsed through sieve. This work was completed as part of ASAC project 1156 (ASAC_1156). See also the metadata record 'Subantarctic Zone (SAZ) Sediment Trap Moorings' (SAZOTS).