Pulse Amplitude Modulation (WaterPAM, Walz) was used to measure the response of the sea ice brine microalgae to CO2 stress. All data was reported in WinControl software and follows standard formats. Three incubation experiments were carried out at SIPEX stations 4 (expt 1) 7 (expt 3) and 8 (expt 4). File nomenclature TO: time zero TR1,2,3 refers to times 2,3 and 4 respectively In expt 4 the coding refers to hours since beginning of experiment Each file contains data in the same columns: Important results include Column E: F Column F: Fm Column G: Fv/Fm Column H: rETR Column I: PAR

This data set contains primary productivity, pulse amplitude modulated fluorometry, and nutrient drawdown numbers associated with the abstract presented below. 14C Primary Productivity Gross column-integrated primary productivity determined through measurement of NaH14CO3 uptake by phytoplankton (1 hour incubations). Primary productivity was modelled from photosynthesis v irradiance curves, chlorophyll profiles, photosynthetically active radiation, and vertical light attenuation. Data for these parameters are also shown. Nutrient Draw-down Data Seasonal depletion of oxidised inorganic nitrogen and silicate in the mixed layer, and production of oxygen. Data was calculated by the subtraction of mixed layer concentrations (uM) from values below the mixed layer. Pulse Amplitude Modulated Fluorometry Data Fv/Fm values determined using pulse amplitude modulated fluorometry (PAM). Samples were dark-adapted prior to measurement so that non-photochemical quenching was relaxed. Values provide an indication of cell health. Abstract Primary productivity was measured in the Indian Sector of the Southern Ocean (30 degrees to 80 degrees E) as part of a multi-disciplinary study during austral summer; Baseline Research on Oceanography, Krill and the Environment, West (BROKE-West Survey, 2006). Gross integrated (0-150 m) productivity rates within the marginal ice zone (MIZ) were significantly higher than within the open ocean, with averages of 2110.2 plus or minus 1347.1 and 595.0 plus or minus 283.0 mg C m-2 d-1, respectively. In the MIZ, high productivity was associated with shallow mixed layer depths and increased Pmax up to 5.158 mg C (mg chl a)-1 h-1. High Si:N drawdown ratios in the open ocean (4.1 plus or minus 1.5) compared to the MIZ (2.2 plus or minus 0.79) also suggested that iron limitation was important for the control of productivity. This was supported by higher Fv/Fm ratios in the MIZ (0.50 plus or minus 0.11 above 40 m) compared to the open ocean (0.36 plus or minus 0.08). As well, in the open ocean there were regions of elevated productivity associated with the seasonal pycnocline where iron availability was possibly increased. High silicate drawdown in the north-eastern section of the BROKE-West survey area suggested significant diatom growth and was linked to the presence of the southern Antarctic Circumpolar Current front (sACCF). However, low assimilation numbers (12.8 to 23.2 mg C mg chl a-1 d-1) and Fv/Fm ratios indicated that cells were senescent with initial growth occurring earlier in the season. In the western section of the survey area within the MIZ, high NO3 drawdown but relatively low silicate drawdown were associated with a Phaeocystis bloom. NO3 concentrations were strongly negatively correlated with column-integrated productivity and chlorophyll biomass which was expected given the requirement for this nutrient by all phytoplankton groups. Regardless, concentrations of both NO3 and silicate were above limiting levels within the entire BROKE-West survey area (N greater than 15.7 micro M, Si greater than 18.3 micro M) supporting the high nutrient low chlorophyll status of the Southern Ocean.

This data set was collected from a ocean acidification minicosm experiment performed at Davis Station, Antarctica during the 2014/15 summer season. It includes: - description of methods for all data collection and analyses. - marine microbial community data; Chlorophyll a concentration, particulate organic matter concentration (carbon and nitrogen), bacterial cell abundance. - phytoplankton primary productivity data; 14C-sodium bicarbonate incorporation raw data (decays per minute: DPM) and modelled productivity from photosynthesis versus irradiance (PE) curves, O2-evolution derived net community productivity, respiration, and gross primary productivity. - phytoplankton photophysiology data; community photosynthetic efficiency from PAM measurements (maximum quantum yield of PSII: Fv/Fm), PAM steady state light curve data and derived non-photochemical quenching of Chl a fluorescence (NPQ), relative electron transport rates (rETR), and effective quantum yield of PSII (delta F/Fm'). - phytoplankton carbon concentrating mechanism (CCM) data; maximum quantum yield of PSII (Fv/Fm) and effective quantum yield of PSII (∆F/Fm') from PAM measurements on size-fractionated phytoplankton samples (less than 10 microns and greater than 10 microns cells) exposed to; ethoxzolamide (EZA) which inhibits both intracellular carbonic anhydrase (iCA) and extracellular carbonic anhydrase (eCA), acetazolamide (AZA), which blocks eCA only, and a control (no inhibitor) sample. - bacterial productivity data; 14C-Leucine incorporation raw data (decays per minute: DPM) and calculated productivity.

General overview The following datasets are described by this metadata record, and are available for download from the provided URL. - Raw log files, physical parameters raw log files - Raw excel files, respiration/PAM chamber raw excel spreadsheets - Processed and cleaned excel files, respiration chamber biomass data - Raw rapid light curve excel files (this is duplicated from Raw log files), combined dataset pH, temperature, oxygen, salinity, velocity for experiment - Associated R script file for pump cycles of respirations chambers #### Physical parameters raw log files Raw log files 1) DATE= 2) Time= UTC+11 3) PROG=Automated program to control sensors and collect data 4) BAT=Amount of battery remaining 5) STEP=check aquation manual 6) SPIES=check aquation manual 7) PAR=Photoactive radiation 8) Levels=check aquation manual 9) Pumps= program for pumps 10) WQM=check aquation manual #### Respiration/PAM chamber raw excel spreadsheets Abbreviations in headers of datasets Note: Two data sets are provided in different formats. Raw and cleaned (adj). These are the same data with the PAR column moved over to PAR.all for analysis. All headers are the same. The cleaned (adj) dataframe will work with the R syntax below, alternative add code to do cleaning in R. Date: ISO 1986 - Check Time:UTC+11 unless otherwise stated DATETIME: UTC+11 unless otherwise stated ID (of instrument in respiration chambers) ID43=Pulse amplitude fluoresence measurement of control ID44=Pulse amplitude fluoresence measurement of acidified chamber ID=1 Dissolved oxygen ID=2 Dissolved oxygen ID3= PAR ID4= PAR PAR=Photo active radiation umols F0=minimal florescence from PAM Fm=Maximum fluorescence from PAM Yield=(F0 – Fm)/Fm rChl=an estimate of chlorophyll (Note this is uncalibrated and is an estimate only) Temp=Temperature degrees C PAR=Photo active radiation PAR2= Photo active radiation2 DO=Dissolved oxygen %Sat= Saturation of dissolved oxygen Notes=This is the program of the underwater submersible logger with the following abreviations: Notes-1) PAM= Notes-2) PAM=Gain level set (see aquation manual for more detail) Notes-3) Acclimatisation= Program of slowly introducing treatment water into chamber Notes-4) Shutter start up 2 sensors+sample…= Shutter PAMs automatic set up procedure (see aquation manual) Notes-5) Yield step 2=PAM yield measurement and calculation of control Notes-6) Yield step 5= PAM yield measurement and calculation of acidified Notes-7) Abatus respiration DO and PAR step 1= Program to measure dissolved oxygen and PAR (see aquation manual). Steps 1-4 are different stages of this program including pump cycles, DO and PAR measurements. 8) Rapid light curve data Pre LC: A yield measurement prior to the following measurement After 10.0 sec at 0.5% to 8%: Level of each of the 8 steps of the rapid light curve Odessey PAR (only in some deployments): An extra measure of PAR (umols) using an Odessey data logger Dataflow PAR: An extra measure of PAR (umols) using a Dataflow sensor. PAM PAR: This is copied from the PAR or PAR2 column PAR all: This is the complete PAR file and should be used Deployment: Identifying which deployment the data came from #### Respiration chamber biomass data The data is chlorophyll a biomass from cores from the respiration chambers. The headers are: Depth (mm) Treat (Acidified or control) Chl a (pigment and indicator of biomass) Core (5 cores were collected from each chamber, three were analysed for chl a), these are psudoreplicates/subsamples from the chambers and should not be treated as replicates. #### Associated R script file for pump cycles of respirations chambers Associated respiration chamber data to determine the times when respiration chamber pumps delivered treatment water to chambers. Determined from Aquation log files (see associated files). Use the chamber cut times to determine net production rates. Note: Users need to avoid the times when the respiration chambers are delivering water as this will give incorrect results. The headers that get used in the attached/associated R file are start regression and end regression. The remaining headers are not used unless called for in the associated R script. The last columns of these datasets (intercept, ElapsedTimeMincoef) are determined from the linear regressions described below. To determine the rate of change of net production, coefficients of the regression of oxygen consumption in discrete 180 minute data blocks were determined. R squared values for fitted regressions of these coefficients were consistently high (greater than 0.9). We make two assumptions with calculation of net production rates: the first is that heterotrophic community members do not change their metabolism under OA; and the second is that the heterotrophic communities are similar between treatments. #### Combined dataset pH, temperature, oxygen, salinity, velocity for experiment This data is rapid light curve data generated from a Shutter PAM fluorimeter. There are eight steps in each rapid light curve. Note: The software component of the Shutter PAM fluorimeter for sensor 44 appeared to be damaged and would not cycle through the PAR cycles. Therefore the rapid light curves and recovery curves should only be used for the control chambers (sensor ID43). The headers are PAR: Photoactive radiation relETR: F0/Fm x PAR Notes: Stage/step of light curve Treatment: Acidified or control The associated light treatments in each stage. Each actinic light intensity is held for 10 seconds, then a saturating pulse is taken (see PAM methods). After 10.0 sec at 0.5% = 1 umols PAR After 10.0 sec at 0.7% = 1 umols PAR After 10.0 sec at 1.1% = 0.96 umols PAR After 10.0 sec at 1.6% = 4.32 umols PAR After 10.0 sec at 2.4% = 4.32 umols PAR After 10.0 sec at 3.6% = 8.31 umols PAR After 10.0 sec at 5.3% =15.78 umols PAR After 10.0 sec at 8.0% = 25.75 umols PAR This dataset appears to be missing data, note D5 rows potentially not useable information See the word document in the download file for more information.

1. In situ chlorophyll fluorescence measurements using pulse amplitude technique (PAM) of macroalga Desmarestia menziesii, assessing adaptation to high light exposure after sea ice breakout, and impact of Thala Valley tip wastes. 2. In situ chlorophyll fluorescence measurements using pulse amplitude technique (PAM) of sediment diatom material assessing adaptation to high light exposure after sea ice breakout, and impact of Thala Valley tip wastes. 3. In situ chlorophyll fluorescence measurements using pulse amplitude technique (PAM) of sponge Latrunculia decipiens assessing adaptation to high light exposure after sea ice breakout. 4. Ecotoxicological experiments where Desmarestia menziesii was exposed to copper in indoor aquaria, aim to determine EC50, NOEC, LOEC for copper. 5. Field collections of various macroalgae for stable isotope analysis: for determination of physiological mechanisms. 6. Field collections of sponge and diatom material for pigment analysis.

This data set was collected during an ocean acidification mesocosm experiment performed at Davis Station, Antarctica during the 2014/15 summer season. It includes: - description of methods for all data collection and analyses. - diatom cell volume - bulk silicification - species specific silicification via fluorescence microscopy - bulk community Fv/Fm on day 12 - single-cell PAM fluorometry data (maximum quantum yield of PSII: Fv/Fm) A natural community of Antarctic marine microbes from Prydz Bay, East Antarctica were exposed to a range of CO2 concentrations in 650 L minicosms to simulate possible future ocean conditions up to the year ~2200. Diatom silica precipitation rates were examined at CO2 concentrations between 343 to 1641 micro atm, measuring both the total diatom community response and that of individual species, to determine whether ocean acidification may influence future diatom ballast and therefore alter carbon and silica fluxes in the Southern Ocean. Described and analysed in: Antarctic diatom silicification diminishes under ocean acidification (submitted for review) Methods described in: Antarctic diatom silicification diminishes under ocean acidification (submitted for review) Location: Prydz bay, Davis Station, Antarctica (68 degrees 35'S, 77 degrees 58' E) Date: Summer 2014/2015 Worksheet descriptions: Bulk silicification - raw data Measured total and incorporated biogenic silica using spectrophotometer for all tanks on day 12 after 24 h incubation with PDMPO - raw data Bulk Fv/Fm - dark-adapted maximum quantum efficiency of PSII (Fv/Fm) on whole community - raw data Measured Fv/Fm of individual cells from 3 mesocosm tanks. Single-cell silicificiation, Fluorescence microscopy - raw data Measured autofluorescence and PDMPO fluorescence of individual diatoms from 6 mesocosm tanks Single-cell PAM, dark-adapted maximum quantum efficiency of PSII (Fv/Fm) - raw data Measured Fv/Fm of individual cells from 3 mesocosm tanks. Cell volume Calculated cell volume (um3) of 7 species from minicosm tanks 1 and 6 - raw data Abbreviations: Fv/Fm Maximum quantum yield of PSII PDMPO 2-(4-pyridyl)-5-((4-(2-dimethylaminoethylaminocarbamoyl)methoxy)phenyl)oxazole Tant Thalassiosira antarctica DiscLg Large Discoid centric diatoms Stella Stellarima microtrias Chaeto Chaetoceros spp. Prob Proboscia truncata Pseu Pseudonitzschia turgiduloides FragLg Fragilariopsis cylindrus / curta Centric Large Discoid centric diatoms LargeThalassiosira Large Discoid centric diatoms

During the K-Axis marine voyage from mid Jan-late Feb 2016, a diverse range of sampling techniques were employed to collect specimens and data. Each sampling event was recorded by scientists and technical support staff in a logbook that was kept in the operations room on board the Aurora Australis. This is a PDF of the scanned original document, compiled on paper during the voyage. event_number: A unique event identifier in the log, in the order that the events were written down (usually but not always chronologically) event_type: The code defined and used by each research project to identify the types of equipment deployed or samples collected for an event. event_type_prefix: A non-mandatory prefix field used by some research projects to identify the type of an event event_type_number: A sequential number or alphanumeric-number combination defined and used by each research project to identify unique equipment deployment or sample collection events station_number: A universal (voyage-wide) station number used across all projects to identify a nominal lat/lon position defined during voyage planning leg: A nominally straight-line section of the voyage track defined during voyage planning. The voyage track was planned as a series of roughly N-S and E-W transects that intersected in some locations. Legs start at a station and continue through more stations to a vertex-station which is the start of the next leg. Legs are numbered consecutively. waypoint: A GPS waypoint used by Aurora Australis crew, AAD science technical support and researchers to identify target lat/lon positions in the voyage. Some waypoints correspond with station numbers. start_date_utc: The start date of the event in UTC start_time_utc: The start time of the event in UTC start_lat_deg: The latitude (whole degrees) of the vessel at the beginning of the event start_lat_min: The latitude (minutes) of the vessel at the beginning of the event start_lat_dec_deg: The latitude (decimal degrees) of the vessel at the beginning of the event start_lon_deg: The longitude (whole degrees) of the vessel at the beginning of the event start_lon_min: The longitude (minutes) of the vessel at the beginning of the event start_lon_dec_deg: The longitude (decimal degrees) of the vessel at the beginning of the event end_date_utc: The end date of the event in UTC end_time_utc: The end time of the event in UTC end_lat_deg: The latitude (whole degrees) of the vessel at the end of the event end_lat_min: The latitude (minutes) of the vessel at the end of the event end_lat_dec_deg: The latitude (decimal degrees) of the vessel at the end of the event end_lon_deg: The longitude (whole degrees) of the vessel at the end of the event end_lon_min: The longitude (minutes) of the vessel at the end of the event end_lon_dec_deg: The longitude (decimal degrees) of the vessel at the end of the event remarks: Comments/remarks written by researchers when completing the paper log

During the K-Axis marine voyage from mid Jan-late Feb 2016, a diverse range of sampling techniques were employed to collect specimens and data. Each sampling event was recorded by scientists and technical support staff in a logbook that was kept in the operations room on board the Aurora Australis. This is a direct digital copy/transcription of the paper logbook. event_number: A unique event identifier in the log, in the order that the events were written down (usually but not always chronologically) event_type: The code defined and used by each research project to identify the types of equipment deployed or samples collected for an event. event_type_prefix: A non-mandatory prefix field used by some research projects to identify the type of an event event_type_number: A sequential number or alphanumeric-number combination defined and used by each research project to identify unique equipment deployment or sample collection events station_number: A universal (voyage-wide) station number used across all projects to identify a nominal lat/lon position defined during voyage planning leg: A nominally straight-line section of the voyage track defined during voyage planning. The voyage track was planned as a series of roughly N-S and E-W transects that intersected in some locations. Legs start at a station and continue through more stations to a vertex-station which is the start of the next leg. Legs are numbered consecutively. waypoint: A GPS waypoint used by Aurora Australis crew, AAD science technical support and researchers to identify target lat/lon positions in the voyage. Some waypoints correspond with station numbers. start_date_utc: The start date of the event in UTC start_time_utc: The start time of the event in UTC start_lat_deg: The latitude (whole degrees) of the vessel at the beginning of the event start_lat_min: The latitude (minutes) of the vessel at the beginning of the event start_lat_dec_deg: The latitude (decimal degrees) of the vessel at the beginning of the event start_lon_deg: The longitude (whole degrees) of the vessel at the beginning of the event start_lon_min: The longitude (minutes) of the vessel at the beginning of the event start_lon_dec_deg: The longitude (decimal degrees) of the vessel at the beginning of the event end_date_utc: The end date of the event in UTC end_time_utc: The end time of the event in UTC end_lat_deg: The latitude (whole degrees) of the vessel at the end of the event end_lat_min: The latitude (minutes) of the vessel at the end of the event end_lat_dec_deg: The latitude (decimal degrees) of the vessel at the end of the event end_lon_deg: The longitude (whole degrees) of the vessel at the end of the event end_lon_min: The longitude (minutes) of the vessel at the end of the event end_lon_dec_deg: The longitude (decimal degrees) of the vessel at the end of the event remarks: Comments/remarks written by researchers when completing the paper log transcribe_comments: Comments/remarks made by the transcriber when the log was digitised

The Kerguelen Axis voyage was planned to collect data to enhance the realism of end-to-end ecosystem models being developed in the Antarctic Climate and Ecosystems Cooperative Research Centre, to investigate the effects of climate change and ocean acidification on Southern Ocean ecosystems in the Indian Sector (particularly in relation to factors affecting the northern distribution of Antarctic krill) and to contribute to assessment of the spatial relationship of mesopelagic mid-trophic level species, in particular zooplanktivores, to foraging strategies by marine mammals and birds on the Kerguelen Plateau. Nine projects were undertaken aboard the Aurora Australis. Each project had individual objectives and outputs, and there are metadata records for each data set collected. They were designed to be complementary in order that the whole data set and project analyses could be used to address the objectives of the Kerguelen Axis program. Observations will be contributed to the Southern Ocean Observing System (SOOS) and will facilitate the design of future ecosystem observing in the region.

During the K-Axis marine voyage from mid Jan-late Feb 2016, a diverse range of sampling techniques were employed to collect specimens and data. Each sampling event was recorded by scientists and technical support staff in a logbook that was kept in the operations room on board the Aurora Australis. This is a direct digital transcription of the paper logbook with interpolated lat/lon from underway data to supplement start times as recorded in the log. The method used to obtain the supplementary position is described in the associated eventlog_matchup.html file. event_number: A unique event identifier in the log, in the order that the events were written down (usually but not always chronologically) event_type: The code defined and used by each research project to identify the types of equipment deployed or samples collected for an event. event_type_prefix: A non-mandatory prefix field used by some research projects to identify the type of an event event_type_number: A sequential number or alphanumeric-number combination defined and used by each research project to identify unique equipment deployment or sample collection events station_number: A universal (voyage-wide) station number used across all projects to identify a nominal lat/lon position defined during voyage planning leg: A nominally straight-line section of the voyage track defined during voyage planning. The voyage track was planned as a series of roughly N-S and E-W transects that intersected in some locations. Legs start at a station and continue through more stations to a vertex-station which is the start of the next leg. Legs are numbered consecutively. waypoint: A GPS waypoint used by Aurora Australis crew, AAD science technical support and researchers to identify target lat/lon positions in the voyage. Some waypoints correspond with station numbers. start_date_utc: The start date of the event in UTC start_time_utc: The start time of the event in UTC start_lat_deg: The latitude (whole degrees) of the vessel at the beginning of the event start_lat_min: The latitude (minutes) of the vessel at the beginning of the event start_lat_dec_deg: The latitude (decimal degrees) of the vessel at the beginning of the event start_lon_deg: The longitude (whole degrees) of the vessel at the beginning of the event start_lon_min: The longitude (minutes) of the vessel at the beginning of the event start_lon_dec_deg: The longitude (decimal degrees) of the vessel at the beginning of the event end_date_utc: The end date of the event in UTC end_time_utc: The end time of the event in UTC end_lat_deg: The latitude (whole degrees) of the vessel at the end of the event end_lat_min: The latitude (minutes) of the vessel at the end of the event end_lat_dec_deg: The latitude (decimal degrees) of the vessel at the end of the event end_lon_deg: The longitude (whole degrees) of the vessel at the end of the event end_lon_min: The longitude (minutes) of the vessel at the end of the event end_lon_dec_deg: The longitude (decimal degrees) of the vessel at the end of the event remarks: Comments/remarks written by researchers when completing the paper log transcribe_comments: Comments/remarks made by the transcriber when the log was digitised utc: The start date and time of the event in UTC start_lon_dec_deg_interp: The latitude (decimal degrees) of the vessel at the beginning of the event interpolated from the vessel underway data start_lat_dec_deg_interp: The longitude (decimal degrees) of the vessel at the beginning of the event interpolated from the vessel underway data