This data were collected on the sixth Nella Dan voyage of a long term field survey project being conducted by the Australian Antarctic Division, to collect distribution, abundance and population structure data for the krill Euphausia superba in the Prydz Bay region, Antarctica. This voyage, the Australian Antarctic Marine Biological Ecosystem Research 1986/1987 (AAMBER 86/87) cruise, operated between February and April 1987. During March, a survey of the krill population and zooplankton community was conducted, to determine the late summer distribution and abundance of krill, especially the larvae. This was done as a follow up to SIBEX II in mid-summer (Janurary) 1985. The major species investigated were Euphausia superba, Euphausia frigidia, Euphausia crystallorophias and Thysanoessa marcuria. Phytoplankton pigment analysis was also conducted at each CTD station site.

Metadata record for data from ASAC Project 2337 See the link below for public details on this project. ---- Public Summary from Project ---- The experimental krill research program is focused 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 and ageing of krill. From the abstracts of some of the referenced papers: Nucleic acid contents of tissue were determined from field-caught Antarctic krill to determine whether they could be used as an alternative estimator of individual growth rates which can currently only be obtained by labour intensive on-board incubations. Krill from contrasting growth regimes from early and late summer exhibited differences in RNA-based indices. There was a significant correlation between the independently measured individual growth rates and the RNA-based indices. There was a significant correlation between the independently measured individual growth rates and the RNA:DNA ratio and also the RNA concentration of krill tissue, although the strength of the relationship was only modest. DNA concentration, on average, was relatively constant, irrespective of the growth rates. The moult stage did not appear to have a significant effect on the nucleic acid contents of tissue. Overall, the amount of both nucleic acids varied considerably between individuals. Nucleic acid-based indicators may provide information concerning the recent growth and nutritional status of krill and further experimentation under controlled conditions is warranted. The are, however, reasonably costly and time-consuming measurements. Growth rates of Antarctic krill Euphausia superba Dana in the Indian Ocean sector of the Southern Ocean were measured in 4 summers. Growth rate was measured using an 'instantaneous growth rate' technique which involved measuring the mean change in length if the uropods at moulting. In the first 4 days following collection mean growth rates ranged from 0.35 to 7.34% per moult in adults and 2.42 to 9.05% in juveniles. Mean growth rates of adult and juvenile krill differed between areas and between the different years of the investigation. When food was restricted under experimental conditions, individual krill began to shrink immediately and mean population growth rates decreased gradually, becoming negative after as little as 7 days. Populations of krill which exhibited initial growth rates began to shrink later than those which had initially been growing more slowly. Data were collected on growth rates of krill. These data were collected as part of ASAC projects 34, 1074, 2220 and 2337. ASAC_34 - Ecophysiology of Antarctic Krill 'Euphausia superba' ASAC_1074 - Seasonal growth in krill ASAC_2220 - Collection of live Antarctic krill ASAC_2337 - Experimental studies into growth and ageing of krill The fields in this dataset are: Field season (eg FS9596 = Field Season 1995-1996) Area (eg Indian Ocean) Cruise Month Date Latitude Longitude Total Number of Krill Dead Krill Moulted Krill Experiment ID Station ID Sample ID Sex Growth (IGR%) (% growth at time of moulting) Uropod Size (mm) Days after capture (when moulted) Standard length

These data were collected during the BROKE-West voyage of the 2005-2006 season. They are numbers of krill larvae per cubic metre of water at each of the stations at which data were collected. The data cover three species of Antarctic krill - Euphausia crystallorophias, Euphausia superba and Thysanoessa macrura. The superba data have been published in the Kawaguchi et al paper, "Krill demography and large-scale distribution in the Western Indian Ocean sector of the Southern Ocean (CCAMLR Division 58.4.2) in Austral summer of 2006". The data for the other species will be presented in a forthcoming paper by Kerrie Swadling. This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679).

This dataset contains results from the Antarctic Division BIOMASS Experiment II (ADBEX II) cruise of the Nella Dan. This is the third cruise of six, and follows the ADBEX I cruise made during late 1982. ADBEX II was to have been an international experiment, Second International BIOMASS Experiment I (SIBEX I), in cooperation with Japan, South Africa and France, however due to the delay of a supply program Australia's participation was cancelled. ADBEX II is the result of a reduced sampling program carried out during the resupply of Davis and Mawson stations. Surveys of krill and other zooplankton were taken off Antarctica in the Australian sector (Mawson to Davis region) and Prydz Bay in January 1984. 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. Results from hydroacoustic surveys of krill biomass were also obtained, as well as CTD and chlorophyll data. Summary results are listed in the documentation.

Echosounder data were collected on a multidisciplinary research voyage conducted from the RV Tangaroa, operated by New Zealand’s National Institute of Water and Atmospheric Research Limited (NIWA). The voyage lasted 42 days, departing from Wellington, New Zealand on January 29th , 2015 and returning to the same port on 11th March 2015. Active acoustic data were obtained continuously using a calibrated scientific echosounder (Simrad EK60, Horten, Norway). The echosounder operated at 38 and 120 kHz for the duration of the voyage with a pulse duration of 1.024 ms, a pulse repetition rate of one ping per second and a 7° beam width. The echosounder data here are a subset of that collected throughout the voyage and include only data from south of 65°S. This subset of data focuses on research questions pertaining to Antarctic blue whales and krill.

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.

Zooplankton were collected with a Rectangular Midwater Trawl (RMT 8+1 net) from 37 sampling sites on and near the Southern Kerguelen Plateau. The contents of each net were preserved in 5% buffered formaldehyde. This dataset covers the counts of the contents of the RMT1 net. The contents were split in the laboratory using a Motoda Box and then identified and counted under a Leica M165C stereo-microscope. A flow meter attached to the mouth of the RMT 8 was used to record the volume of seawater passing through the net, and this volume was converted to water passing through the RMT 1 by applying the conversion factor of 2.027357. The organisms in the samples were identified to the lowest taxonomic level possible. For copepods and euphausiids this level was to species, and generally to sex and/or development stage. For other groups, the identifications were to high levels such as Family or Order.

The data describe all zooplankton species abundance values estimated at each rectangular midwater trawl (RMT 1+8) target and routine sampling site collected during the 2021 TEMPO voyage on R/V Investigator. During the TEMPO voyage, zooplankton were collected using the RMT 1+8 plankton net and sorted down to the lowest taxonomic level possible. The supporting data set, in CSV format, feature abundances estimated from RMT+1 samples only. The data file is named allzooplankton.csv. The fields (columns) in the file are: "Site" – sampling site ID for each routine (RXX) and target (TXX) trawl using RMT1+8. "Date" – date of each sample collected (ie. target or routine trawl) [dd/mm/yyyy]. "Latitude" – latitude of each trawl [degrees] (-dd.ddddd). "Longitude" – longitude of each trawl [degrees] (dd.ddddd). "Chla" – Integrated estimate of chlorophyll-a (mg m^-2) averaged at depths between 10 to 200 m, which aligns with the section of the water column where zooplankton were sampled. "Depth" – Bathymetric depth estimated at each sampling station. "MLD_03" – Mixed layer depth (m). Not used in final analysis. "MLD_05" – Mixed layer depth (m). Not used in final analysis. "MLD_N2max" – Mixed layer depth (m) where the N^2 maximum is found, i.e., the pycnocline. "CT_200" – Absolute temperature (°C) averaged at depths between surface and 200 m maximum net sampling depth. Values are derived from in situ CTD measurements at each sampling site. "SA_200" – Absolute salinity (g kg^-1) averaged at depths between surface and 200 m maximum net sampling depth. Values are derived from in situ CTD measurements at each sampling site. "IceMeltDays" – Number of days since sea ice melted calculated from daily passive microwave estimated percent sea ice concentration taken from the National Snow and Ice Data Centre. "m_to_Ice" – Distance (m) estimated from sampling site to edge of ice. "IceConc" – Actual ice concentration value (%). It is the percentage of an area covered in sea ice. The remaining columns are zooplankton species abundances (individuals per 1000 cubic metres) estimated from count data, volume of original sample, split of sample analysed under the microscope and calibration of the flowmeter: "R.gigas" – Rhincalanus gigas, copepod "C.propinquus" – Calanus propinquus, copepod "C.simillimus" – Calanus simillimus, copepod "C.acutus" – Calanoides acutus, copepod "Metridia sp." – Metridia species, copepod "M.gerlachei" – Metridia gerlachei, copepod "Paraeuchaeta sp." – Paraeuchaeta species, copepod "Pleuromamma sp." – Pleuromamma species, copepod "Oncaea" – Oncaea species, copepod "O.antarctica" – Oncaea antarctica, copepod "Neo tonsus" – Neocalanus tonsus, copepod "Neo gracilis" – Neocalanus gracilis, copepod "Stephos longipes" – Stephos longipes, copepod "Ctenocalanus sp." – Ctenocalanus species, copepod "Microcal pygmaeus" – Microcalanus pygmaeus, copepod "Oithona similis" – Oithona similis, copepod "Oithona frigida" – Oithona frigida, copepod "Heterhabdus australis" – Heterorhabdus australis, copepod "Heterhabdus sp." – Heterorhabdus species, copepod "Harpacticoid" – Harpacticoid species, copepod "Haloptilus sp." – Haloptilus species, copepod "Candacia sp." – Candacia species, copepod "Solecithricella sp." – Solecithricella species, copepod "Clausocalanus breviceps" – Clausocalanus breviceps, copepod "Clausocalanus laticeps" – Clausocalanus laticeps, copepod "Clausocalanus sp." – Clausocalanus species, copepod "Aetideops antarctica – Aetideopsis antarctica, copepod "Aetide minor" – Aetideopsis minro, copepod "Euchirella rostromanga" – Euchirella rostromanga, copepod "Heterostylites longicornis" – Heterostylites longicornis, copepod "Gaidius tenuispinus" – Gaidius tenuispinus, copepod "Gammaridean amphipod" – Gammaridean, amphipod "T.gaudichaudii" – Themisto gaudichaudii, amphipod "Parathemisto sp." – Parathemisto species, amphipod "Hyperia antarctica" – Hyperia antarctica, amphipod "Hyperia sp." – Hyperia species, amphipod "Hyperiella dilatata" –