Metadata record for data from AAS (ASAC) Project 2337. An excel spreadsheet is available for download from the URL given below. The spreadsheet contains three worksheets: a summary of the data validated data all data Public The experimental krill research program is focussed on obtaining life history information of use in managing the krill fishery - the largest Antarctic fishery. In particular, the program will concentrate on studies into schooling, growth, ageing, behaviour and reproduction of krill as well as into the operation, behaviour and trends of the krill fishery. Project objectives: To investigate key aspects of the biology of Antarctic krill and its management utilising the facilities at the Australian Antarctic Division. Taken from the 2008-2009 Progress Report: Progress against objectives: We succeeded to take krill larvae reproduced in-house last year up to adult stage (external maturity) for the first time in our research laboratory (the second facility ever outside Antarctica), which means that last year's larvae reached maturity within a year in our aquarium, compared to 2-3 years in the wild, however spawning from this population is yet to be recorded. We also had successful reproduction this year and currently these animals are at late larval stage. We have now succeeded in reproduction two years in a row and have established the technique. This is a major step forward in closing Antarctic krill's life cycle in our aquarium. This achievement makes us the only research facility outside Antarctica to be able to conduct live krill experiments for the entire life stage and contribute information on biological parameters important for krill management. Taken from the 2009-2010 Progress Report: Progress against objectives: This year for the first time we have succeeded in closing the entire krill life cycle in our research laboratory (the second facility ever outside Antarctica. We also achieved successful reproduction this year and currently these animals are at the late larval stage. We have now succeeded in krill reproduction for three years in a row and have firmly established the technique. This achievement makes us the only research facility outside Antarctica to be able to conduct live krill experiments for the entire life stage and contribute information on biological parameters important for krill management. Taken from the 2010-2011 Progress Report: Public summary of the season progress: Understanding how krill may respond to various environments is the fundamental information to predict the future of krill centric ecosystem under the climate change. The project's current focus is to study impacts of ocean acidification on krill. The AAD aquarium facility for ocean acidification study is continuing to be upgraded to increase its capacity and stability to undertake its experiments at larger scale. Negative impacts of ocean acidification on krill has been investigated and the range of CO2 level fatal to krill embryonic development was broadly identified, and was published for the first time.

Crustaceans grow or shrink in size as they moult. Length of discarded moults represent length of animals before their moulting events. Therefore, by measuring length of discarded moult and length of animal after moult, growth increments at the time of moult can be obtained. IGR is defined as the growth increment expressed as a proportion of pre-moult total length (TL). IGR can be converted into daily growth rate for a given value of TL by calculating absolute growth increment and dividing by an estimate of inter-moult period (IMP). The IGR technique depends on the collection of live krill in good condition. Krill were caught with an RMT-8 net and individual freshly caught animals were randomly selected from the catch and immediately transferred to individual jars. They were then maintained onboard and checked regularly for moults for up to 5 days following capture. The experiments were run a flowthrough seawater system which used 250 ml jars with small holes to allow water exchange in a large flow-through tank of seawater maintained at ambient ocean temperature. No additional food was provided. The system allowed experiments with over 4000 krill. Each krill was checked daily after capture to ascertain whether it had moulted. If an animal had moulted, then the animal and its moult were collected and frozen in liquid nitrogen or at -85 degrees C to be measured back ashore. The growth rate will be estimated from the difference in length of the uropod of the moult and that of the whole post-moult krill. This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679).

Distribution and abundance of zooplankton, krill and fish were observed on the K-axis transect using deployments of RMT1+8 net. Towing speed of the RMT1+8 were approximately 2 knots. All krill, fish and squid in the catch were sorted, identified to species and counted. The density at each station were determined from the counts per calibrated flow-meter readings attached to the net. Morphometric measures were taken and, for larger taxa. List of files K-Axis Morph combined_for data centre.xlsx: Morphological data for all krill and zooplankton captured in RMT-8 net haul. RMT data entry_v1_for data centre.xlsx: Trawl data. RMT8 filtered volume_for data centre.xlsx: Filtered volume for each haul. Map_all.tif: Map showing all trawl stations. Map_RMTR.tif: Map showing only regular trawl stations. Map_RMTT.tif: Mapn showing only target trawl stations. K-Axis description This dataset includes biological data from “K-Axis voyage, 2016 and “Voyage 3, 2015”. [Data from K-Axis voyage, 2016] Distribution and abundance of zooplankton, krill and fish were observed on the K-axis transect using deployments of RMT1+8 net. Towing speed of the RMT1+8 were approximately 2 knots. All krill, fish and squid in the catch were sorted, identified to species and counted. The density at each station were determined from the counts per calibrated flow-meter readings attached to the net. Morphometric measures were taken and, for larger taxa. -List of files- K-Axis Morph combined_for data centre.xlsx: Morphological data for all krill and zooplankton captured in RMT-8 net haul. Map_all.tif Map_RMTR.tif Map_RMTT.tif RMT data entry_v1_for data centre.xlsx: Trawl data. RMT8 filtered volume_for data centre.xlsx: Filtered volume for each haul. [Data from Voyage 3, 2015] The Australian Antarctic research and resupply vessel, RV Aurora Australis, was directed to undertake an opportunistic marine science survey for 17 days during 21 February to 10 March 2015 using ship time that became available due to unexpectedly favourable ice conditions for Mawson station resupply. The purpose of this opportunistic Marine Science work was to assess: 1. The spatial variability, particularly along the shelf break, of the prey field for penguins, flying seabirds and marine mammals in East Antarctica. 2. The small scale variability of prey in key foraging locations near to land-based colonies of penguins and flying seabirds in East Antarctica. 3. Feasibility and potential of utilising annual station resupply voyages as a cost effective means to undertake monitoring and research to better understand the ecosystem in the region. The survey completed 5 acoustic box surveys including a total of 53 RMT target and routine trawls, 6 demersal trawls, 131 phytoplankton samples from underway sampling, and 214 hourly observations of predators. These activities were successfully supervised remotely. -List of files- emm-15-22.pdf: Prelminary report of the voyage to CCAMLR WG-EMM Figure_V3_all_euphausiids.pdf: Map of Euphausiid abundance distribution. Figure_V3_Clione_antarctica.pdf: Map of Clione antarctica abundance distribution. Figure_V3_crystal_krill.pdf: Map of Euphausia crystallorophias abundance distribution. Figure_V3_frigida.pdf: Map of Euphausia frigida abundance distribution. Figure_V3_larval_fish_abundances.pdf: Map of fish larvae abundance distribution. Figure_V3_superba.pdf: Map of Antarctic krill abundance distribution. Figure_V3_tmacrura.pdf: Map of Thysanoessa macrura abundance distribution. V3_final_for data centre.xlsx: Trawl station data and density data of each taxa caught. Voyage 3 Marine Science Program Final.docx: Voyage report.

These data represent the results of the first study to use Earth System Model (ESM) outputs of SST and chlorophyll-a to simulate circumpolar krill growth potential for the recent past (1960-1989) and future climate change scenarios (2070-2099). Growth potential is obtained using an empirically-derived krill growth model (Atkinson et al. 2006, Limnol. Oceanogr.), where growth is modeled as a function of SST and chlorophyll-a. It serves as an approximation of habitat quality, as areas that support high growth rates are assumed to be good habitat (see Murphy et al., 2017, Sci Rep). To increase confidence in the future projections, ESMs were selected and weighted for each season based on their skill at reproducing observation-based krill growth potential for the recent past. First, eleven ESMs which provided SST and chlorophyll-a outputs were obtained from the Coupled Model Inter-comparison Project 5 archive. These included: CanESM2, CMCC-CESM, CNRM-CM5, GFL-ESM2G, GFDL-ESM2M, GISS-E2-H-CC, HadGEM2-CC, IPSL-CM5A-LR, MPI-ESM-MR, MRI-ESM1 and NorESM1-ME. For each ESM, seasonal surface averages of SST and chlorophyll-a were used to calculate growth potential for the historical scenario (1960-1989), which was then bilinearly interpolated on to the same 1°x1° grid. Satellite observation-based datasets for SST and chlorophyll-a were used to calculate observation-based growth potential for the recent past (1997-2010). These comprised seasonal surface averages of SST (from the OISST v2 daily dataset, 1/4⁰ horizontal resolution) and chlorophyll-a (the mean of the SeaWiFS and Johnson et al. (2013) corrected estimate of SeaWiFS daily datasets, 1/12⁰ horizontal resolution). Observation-based growth potential was then bilinearly interpolated onto the same grid as the ESMs. ESM skill for each season was subsequently assessed against observation-based growth potential using a Taylor Diagram. The ESMs were selected and weighted according to their performance to produce a weighted subset (see "ESM_weighting_method.pdf" file). Of the netcdfs provided, "hist_mean_ensemble.nc" represents the unweighted mean of seasonal growth potential, calculated from the initial ensemble of eleven ESMs for the historical scenario. The "hist_mean_subset.nc" file represents the analogous output of the weighted subset. Future projections of seasonal growth potential for Representative Concentration Pathways (RCPs) 4.5 and 8.5 were obtained using the weighted subset for the period of 2070-2099. These projected seasonal surface averages are provided in the "rcp45_mean_subset.nc" and "rcp85_mean_subset.nc" files. RCPs represent standard climate change scenarios developed by the Intergovernmental Panel on Climate Change, with 4.5 reflecting some mitigation of carbon emissions, and 8.5 being the "business as usual" scenario. Analogous netcdfs for the weighted subset outputs of chlorophyll-a (chl) and SST (tos) for the historical and RCP scenarios are also provided in the "chl_tos_netcdfs.zip" file so that the driving environmental variables underlying growth potential can be examined.

Instantaneous growth rates (IGR) of Antarctic krill kept under experimental conditions were measured. The measured appendages included the uropods, telson (both standard length measurements with the IGR technique) and the pleopod endopodite and pleopod exopodite were investigated as an alternate length measurement. IGR measurements were recorded on 90 experimental animals. The total carbon content of 45 krill of various size ranges (collected directly from the field) was determined. The relationship between the change in length in carbon as a function of growth was investigated. The parameters measured were total length, mean uropod length, telson length, wet weight, dry weight and total carbon content. This dataset was collected as part of ASAC project 141. See metadata record ASAC_141 - Collection of live Antarctic krill 'Euphausia superba'. The fields in this dataset are: Krill Total length (mm) Telson length (mm) Mean uropod length (mm) Wet weight (g) Dry weight (g) Dry Weight (mg) Carbon content as a % of dry weight Total carbon content (g) Moult Sex

The embryonic development of Antarctic krill (Euphausia superba) is sensitive to elevated seawater CO2 levels. This data set provides the experimental data and WinBUGS code used to estimate hatch rates under experimental CO2 manipulation, as described by Kawaguchi et al. (2013). Kawaguchi S, Ishida A, King R, Raymond B, Waller N, Constable A, Nicol S, Wakita M, Ishimatsu A (2013) Risk maps for Antarctic krill under projected Southern Ocean acidification. Nature Climate Change (in press) Circumpolar pCO2 projection. To estimate oceanic pCO2 under the future CO2 elevated condition, we computed oceanic pCO2 using a three-dimensional ocean carbon cycle model developed for the Ocean Carbon-Cycle Model Intercomparison Project (2,3) and the projected atmospheric CO2 concentrations. The model used, referred to as the Institute for Global Change Research model in the Ocean Carbon-Cycle Model Intercomparison Project, was developed on the basis of that used in ref. 4 for the study of vertical fluxes of particulate organic matter and calcite. It is an offline carbon cycle model using physical variables such as advection and diffusion that are given by the general circulation model. The model was forced by the following four atmospheric CO2 emission scenarios and their extensions to year 2300. RCP8.5: high emission without any specific climate mitigation target; RCP6.0: medium-high emission; RCP 4.5: medium-low emission; and RCP 3.0-PD: low emission (1). Simulated perturbations in dissolved inorganic carbon relative to 1994 (the Global Ocean Data Analysis Project (GLODAP) reference year) were added to the modern dissolved inorganic carbon data in the GLODAP dataset (5). To estimate oceanic pCO2, temperature and salinity from the World Ocean Atlas data set (6) and alkalinity from the GLODAP data set were assumed to be constant. Marine ecosystems of the Southern Ocean are particularly vulnerable to ocean acidification. Antarctic krill (Euphausia superba; hereafter krill) is the key pelagic species of the region and its largest fishery resource. There is therefore concern about the combined effects of climate change, ocean acidification and an expanding fishery on krill and ultimately, their dependent predators—whales, seals and penguins. However, little is known about the sensitivity of krill to ocean acidification. Juvenile and adult krill are already exposed to variable seawater carbonate chemistry because they occupy a range of habitats and migrate both vertically and horizontally on a daily and seasonal basis. Moreover, krill eggs sink from the surface to hatch at 700–1,000m, where the carbon dioxide partial pressure (pCO2 ) in sea water is already greater than it is in the atmosphere. Krill eggs sink passively and so cannot avoid these conditions. Here we describe the sensitivity of krill egg hatch rates to increased CO2, and present a circumpolar risk map of krill hatching success under projected pCO2 levels. We find that important krill habitats of the Weddell Sea and the Haakon VII Sea to the east are likely to become high-risk areas for krill recruitment within a century. Furthermore, unless CO2 emissions are mitigated, the Southern Ocean krill population could collapse by 2300 with dire consequences for the entire ecosystem. The risk_maps folder contains the modelled risk maps for each of the climate change scenarios (i.e. Figure 4 in the main paper, and Figure S2 in the supplementary information). These are in ESRI gridded ASCII format, on a longitude-latitude grid with 1-degree resolution. Refs: 1. Meinshausen, M. et al. The RCP greenhouse gas concentrations and their extensions from 1765 to 2300. Climatic Change 109, 213-241 (2011). Orr, J. C. et al. Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature 437, 681-686 (2005). Cao, L. et al. The role of ocean transport in the uptake of anthropogenic CO2. Biogeosciences 6, 375-390 (2009). Yamanaka, Y. and Tajika, E. The role

Regular Trawl At each regular trawl station a quantitative standard double oblique tow was conducted from the surface down to 200 m (or to within 10 m of the bottom at stations shallower than 200 m). Such a depth range is considered to be the best compromise between the time available for sampling and the likely vertical depth range of krill. During the hauls, ship speed was maintained at a constant 2.5 plus or minus 0.5 knots. Wire speed of 0.7 to 0.8 m/s during paying out and of 0.3 m/sec during hauling (approx. 0.5 m/s and 0.2 m/s respectively at vertical depth change rate). The net mouth angle is remarkably constant during hauling within the speed ranges given above. When the net reaches maximum depth, the winch was stopped for about 30 seconds to allow the net to stabilise before starting retrieval. When hauling, propeller thrust was turned off when the net reached a depth of 15 to 20 m; this was to minimise the effects of the propeller action on the net operation and avoids damage of the samples. Target Trawl Whenever interesting targets were seen on the echo-sounder, or large amounts of krill were required for any purpose, target trawls were performed. Once the position of the target was marked, the ship was turned and navigated to run over the target from direction required within navigation capacity. The ship speed was lowered down to below 2.0 knots before hitting the target, so that the net could be lowered down to the desired depth whenever the net reached the target. Fine adjustments were made throughout the trawl by monitoring the echo-sounder in the aft control room. For live krill target trawl, ship speed was kept as slow as possible to avoid any damage to krill. Sample processing for all regular trawl stations: RMT-8 1.Measure the total sample volume (Drain water, then measure using water replacement; mandatory only for the regular hauls) 2.Sort out all Antarctic krill and count their number. If the sample mainly consists of krill and the volume is more than ~1L, a known portion of the whole sample was sub-sampled for the further processing. 3.Stage (TL, Carapace Length, Maturity) of all krill (or subsample), up to 50 to 150 individuals, and digestive gland size (the longest axis) of up to 50 individuals were measured using digital calipers. 4.Other zooplankton groups were immediately sorted out from the catch and their numbers were recorded. Preservation of RMT-8 samples Krill (including those used for onboard demography measurements) were fixed in 10% formalin for their further analysis. Whenever excess amount of krill catch were made, they were sampled and frozen for POP (persistent organic pollutant) measurements, preserved in 80% ethanol for genetic analysis, and frozen under -80C/ liquid nitrogen for chemical analysis. Fish were preserved in formalin, EtOH, or frozen. Squids were preserved in ethanol. RMT-1 1.The whole sample was fixed with 10 % formalin. 2.If the sample volume was too large, then a known proportion of catch was randomly sub-sampled and fixed. This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679).

This dataset contains results from the Second International BIOMASS Experiment II (SIBEX II) cruise of the Nella Dan, January 1985. This cruise is the fourth cruise out of a series of six, investigating the distribution, abundance and population structure of krill Euphausia superba in the Prydz Bay region, Antarctica. SIBEX II was co-ordinated with South Africa, Japan and France, and 66 grid sampling stations covered an area from 58 degrees to 93 degrees East and from 60 degrees South to the Antarctic coast. At each sampling station, surveys of krill and other zooplankton were taken, as well as a CTD cast and water collection for phytoplankton pigment, nutrients and primary production measurement. Species identity and abundance data were obtained. The major species investigated were Euphausia superba, Euphausia frigidia, Euphausia crystallorophias and Thysanoessa marcuria. Other pteropods and cephalopods were also studied, as well as results from hydroacoustic surveys of krill biomass. Summary results are listed in the documentation. The fields in this dataset are: species Station Number Haul Type RMT Biomass Weight Flowmeter Latitude Longitude Time Date Ice Sea State Density Sea Floor Maturity This dataset was updated by Angela McGaffin. This download file also contains the original dataset provided in 2007. There are four files available: SIBEX_II_krill.xls (original file) sibex2_krill_morphometrics.xslx sibex2_station_data.xslx sibex2_zooplankton_corrected.xls A minor data update took place on 202211-03 to add a scanned copy of the original acoustics log.

Microscopy imaging of live Antarctic krill using a Leica M205C dissecting stereo-microscope with a Leica DFC 450 camera and Leica LAS V4.0 software. Krill were held in a custom made 'krill trap', details provided in manuscript in section eight of this form. The data are available as a single video file. These data are part of Australian Antarctic Science (AAS) projects 4037 and 4050. Project 4037 - Experimental krill biology: Response of krill to environmental change The experimental krill research project is designed to focus on obtaining life history information of use in managing the krill fishery - the largest Antarctic fishery. In particular, the project will concentrate on studies into impacts of climate change on key aspects of krill biology and ecology. Project 4050 - Assessing change in krill distribution and abundance in Eastern Antarctica Antarctic krill is the key species of the Southern Ocean ecosystem. Its fishery is rapidly expanding and it is vulnerable to changes in climate. Australia has over a decade of krill abundance and distribution data collected off Eastern Antarctica. This project will analyse these datasets and investigate if krill abundance and distribution has altered over time. The results are important for the future management of the fishery, as well as understanding broader ecological consequences of change in this important species.