This metadata record describes at-sea seabird observation dataset collected during the 2021 TEMPO (Trends in Euphausiids off Mawson, Predators, and Oceanography) voyage onboard the RV Investigator (see Kelly et al. 2021 for more details on the voyage). The primary goal of TEMPO was to collect data to estimate krill biomass with a view to update the precautionary catch limit for krill in CCAMLR’s Division 58.4.2-East. The aim of the survey was also to improve our understanding on the connectivity of the krill population, and overlap between krill and predators. The TEMPO voyage ran from February to March 2021. The survey consisted of six major acoustic line-transects to estimate krill biomass and to observe swarm behaviour across ecological and density gradients within the survey area south of 62°S between 55° and 80° E, and a single fine-scale krill box acoustic survey off the Mawson coast. Comprehensive oceanographic (CTDs, XBTs, Argo floats) and biological (plankton) sampling were also conducted to understand the habitat environment of krill and its predators. Predator observation was undertaken throughout the voyage to improve our understanding on the connectivity of the krill population, and overlap of distribution between krill and predators. The information gathered contributes to the design of tractable and sustainable long-term monitoring plan and to evaluate spatial management of the krill fishery. Two seabird observers undertook observations from: 1) an enclosed observation deck above the bridge of the RV Investigator (approx. eye height of 24.3m); 2) on the observation deck 05 with the cetacean observers (approx. eye height of 18.4m); 3) and astern on the same level as the observation deck. Observing was undertaken during daylight hours, and during fair-excellent sighting conditions. Formal observing for seabirds was suspended when the vessel stopped/slowed for other sampling operations. During searching effort, one seabird observer scanned for seabirds and the other logged observations (via radio) in the enclosed observation above the bridge. Seabird searching effort was undertaken with naked-eye and with 10 x 42 binoculars (Swarovski NL Pure). Observers searched in a 300 m quadrat on one side of the vessel (specific side could change, as was best for observing conditions). A number of different seabird observation processes were trialled during the TEMPO voyage, including continuous observations and a snapshot approach with distance sampling (which aims to minimise bias introduced by flying seabirds), and observations astern to try to account for ‘followers’, and incidental sightings outside of these. (See Gierdrum et al. 2012 for more details on the observation processes.) It is hoped these trials will help guide development in the near future of methods for at-sea surveys for seabirds in East Antarctica. Seabird observers achieved sighting effort along 3853 km of trackline, over 126 hrs, both within the TEMPO survey area, and along the transit home. References Gjerdrum, C., D.A. Fifield, and S.I. Wilhelm. 2012. Eastern Canada Seabirds at Sea (ECSAS) standardized protocol for pelagic seabird surveys from moving and stationary platforms. Canadian Wildlife Service Technical Report Series No. 515. Atlantic Region. vi + 37 pp. Kelly, N., Bestley, S., Burns, A., Clarke, L., Collins, K., Cox, M., Hamer, D., King, R., Kitchener, J., Macaulay, G., Maschette, D., Melvin, J., Miller, B., Smith, A., Suter, L., Westwood, K., Wotherspoon, S. and Kawaguchi, S. (2021). An overview of the ecosystem survey to quantify krill abundance for krill monitoring and management in Eastern Sector of CCAMLR Division 58.4.2: Trends in Euphausiids off Mawson, Predators, and Oceanography “TEMPO”, Working Group on Ecosystem Monitoring and Management, CCAMLR, WG-EMM-2021/07, 26pp. TEMPO seabird observation data README Below are basic descriptors of the columns that appear in the various tables describing effort (continous, snapshot, incidental

Raw and processed acoustic data were collected in East Antarctica from the RSV Aurora Australis during two surveys: the Krill Availability, Community Trophodynamics and AMISOR Surveys (KACTAS) and the Krill Acoustics and Oceanography Survey (KAOS) in the East Antarctic. Seabed alias example file used to make Figure 3. 38_false_bottom.sv.csv (file size: 10.7 MB) This file is an example of seabed aliasing (false bottom echo) that occurred during the KAOS survey. The data in this file are acoustic (mean volume backscattering strength, Sv) sample-by-sample and in a CSV format. Ping_index - ping number Distance_GPS - along track distance from the vessel’s GPS (nautical miles). Distance_vl - along track distance from the vessel’s log (nautical miles). Not used here, so is populated by Echoview’s ‘don’t care’ value (-9.90E+37) to keep the file format consistent. Ping_date - format yyyy-mm-dd Ping_time - format hh:mm:ss Ping_milliseconds - format (integer; ms) Latitude - position from the vessel’s GPS (degrees) Longitude position from the vessel’s GPS (degrees) Depth_start - start depth of vessel echosounder logging range (m) Depth_stop - stop depth of vessel echosounder logging range (m) Range_start - start range of vessel echosounder logging range (m) Range_stop - stop range of vessel echosounder logging range (m) Sample_count number of samples in a ping. Acoustic Sv samples follow in column-wise vector (dB re 1 m-1) Transect metadata all_transects.csv (file size: 14.8 K) This is the transect metadata for both the KACTAS and KAOS surveys: Transect - transect number startDate - start date of transect dd/mm/yyyy startTime - start time of transect hh:mm endDate - end date of transect dd/mm/yyyy endTime - end time of transect dd/mm/yyyy Ping_subset - a ping subset specified between two timestamps to isolate acoustic data that occurred on transect , i.e start timestamp to stop timestamp (yyyy-mm-dd hh:mm = yyyy-mm-dd hh:mm). Direction - Direction traveled along the transect (N - north or S- south). Light - day or night when transect was observed Survey - Either KACTAS or KAOS Leg - Krill box 1 or 2 (there were two surveys only during the KAOS voyage). Pass - Sampling bout for a transect in a given direction. Example R-code FigureAndDataprocessingExample.R (12KB) This R-code provides examples of scripting acoustic data processing using EchoviewR, specifically, using ping-subsets to isolate acoustic data along a transect of interest, detecting schools and exporting echo integrations for 38, 120 and 200 kHz. The R-code for making the figures in the paper is also given. GPS vessel positions for both the KACTAS and KAOS surveys KACTASandKAOS_GPS.csv (3 MB) This CSV file gives the vessel track for both the KACTAS and KAOS surveys. GPS_date - dd/mm/yyyy GPS_time - HH:MM:SS GPS_milliseconds - integer Latitude - position from the vessel’s GPS (degrees) Longitude - position from the vessel’s GPS (degrees) x - relative grid position (x) used for plotting Figure 1 y - relative grid position (y) used for plotting Figure 1 Survey - either: KACTAS_Krillbox, KAOS_Krillbox1, or KACTAS_Krillbox2 Krill swarms for both the KACTAS and KAOS surveys KACTASandKAOSswarms.csv (2.1 MB) Krill swarms descriptors for the KACTAS and KAOS surveys in CSV format (see Table 2 for description of the data fields). Echoview file for the KACTAS survey KACTAS-survey.EV (21.8 MB) An Echoview file (version 12.0) for the KACTAS acoustic data analysis KACTAS EK60 scientific echosounder calibration values KACTAS_EK500_calibration.ecs 3,623 16/05/2022 21:21 -a-- An Echoview format calibration file for the KACTAS survey (see Table 3 for calibration values and Demer et al.20 for a description of the calibration parameters). Echoview file for the KAOS survey KAOS-survey.EV (16.4MB) An Echoview file (version 12.0) for the KAOS acoustic data analysis KAOS EK60 scientific echosounder calibration values KAOS_EK60_calibration.ecs 5,711 01/11/2021 04:36 -a– An Echoview format calibration

This is data describing acoustically observed krill swarms that was used in the Bestley et al. (2017) paper 'Predicting krill swarm characteristics important for marine predators foraging off East Antarctica' (http://onlinelibrary.wiley.com/doi/10.1111/ecog.03080/full). Abstract of the paper presented here: Open ocean predator-prey interactions are often difficult to interpret because of a lack of information on prey fields at scales relevant to predator behaviour. Hence, there is strong interest in identifying the biological and physical factors influencing the distribution and abundance of prey species, which may be of broad predictive use for conservation planning and evaluating effects of environmental change. This study focuses on a key Southern Ocean prey species, Antarctic krill Euphausia superba, using acoustic observations of individual swarms (aggregations) from a large-scale survey off East Antarctica. We developed two sets of statistical models describing swarm characteristics, one set using underway survey data for the explanatory variables, and the other using their satellite remotely sensed analogues. While survey data are in situ and contemporaneous with the swarm data, remotely sensed data are all that is available for prediction and inference about prey distribution in other areas or at other times. The fitted models showed that the primary biophysical influences on krill swarm characteristics included daylight (solar elevation/radiation) and proximity to the Antarctic continental slope, but there were also complex relationships with current velocities and gradients. Overall model performance was similar regardless of whether underway or remotely sensed predictors were used. We applied the latter models to generate regional-scale spatial predictions using a 10-yr remotely-sensed time series. This retrospective modelling identified areas off east Antarctica where relatively dense krill swarms were consistently predicted during austral mid-summers, which may underpin key foraging areas for marine predators. Spatiotemporal predictions along Antarctic predator satellite tracks, from independent studies, illustrate the potential for uptake into further quantitative modelling of predator movements and foraging. The approach is widely applicable to other krill-dependent ecosystems, and our findings are relevant to similar efforts examining biophysical linkages elsewhere in the Southern Ocean and beyond. This comma separated variable (CSV) file contains the krill swarm data used in: Bestley, S., Raymond, B., Gales, N.J., Harcourt, R.G., Hindell, M.A., Jonsen, I.D., Nicol, S., Peron, C., Sumner, M.D., Weimerskirch, H. and Wotherspoon, S.J., Cox, M.J. (2017). Predicting krill swarm characteristics important for marine predators foraging off East Antarctica. Ecography. The column descriptions are: Depth_mean_m = (units m) mean depth of a krill swarm Date = (YYYYMMDD) observation date (UTC) Time = (HH:mm:ss.ss) observation time (UTC) Lat = (dd.ddddd) latitude Lon = (ddd.ddddd) longitude transect = BROKE West transect number 7 to 11 (see Fig. 1, Bestley et al. 2017) denVolgm3 = (units g wet mass m-3) internal krill swarm density in gram wet mass per cubic metre.

An integrated, age-structured model was fitted to different combinations of survey data using two forms of selectivity (logistic or double-logistic) with time-constant or annually varying selectivity to investigate the population dynamics of Antarctic krill (Euphausia superba) near the Antarctic Peninsula. The data were from surveys conducted by the U.S. Antarctic Marine Living Resources Program around the South Shetland Islands from 1992 to 2011. Two indices of krill biomass based on (1) trawl-net samples and (2) hydroacoustic sampling were combined with length-compositions from the nets. Sixteen model configurations using different combinations of the two biomass surveys with the various options for modeling selectivities were examined.

The integrated modeling framework for Antarctic krill (Euphausia superba) has been extended to include estimates of krill growth consistent with survey data and to use multi-nation survey data collected from 1981 to 2014 near the Antarctic Peninsula. Four models of the population dynamics of Antarctic krill in Subarea 48.1 based on different aggregations of the data are described to illustrate the capabilities of the framework.

This dataset contains digitized passive acoustic recordings from a hydrophone connected to an autonomous recording device both moored near the sea-floor in the Southern Ocean. Recordings were digitised at a sample rate of 500 Hz and were continuous over the period of operation. The intended purpose of these recordings was to collect baseline data on the acoustic environment (i.e. underwater sound fields). Underwater sounds that were recorded include sounds generated by Antarctic sea ice, marine mammals, and man-made sounds from ships and geo-acoustic surveys. Marine mammal sounds include calls from blue, fin, humpback, and minke whales. The hydrophone was deployed on a mooring on the Kerguelen Plateau.

Metadata record for data from ASAC Project 2683. This project was followed by AAS project 4102, "Population abundance, trend, structure and distribution of the endangered Antarctic blue whale". The metadata record for project 4102 (and its child records) is available at the provided URL. This metadata record is in the process of being gradually modified (2014-08-08) to be set up as a parent record for the data from the above listed projects. Data from these projects will gradually become available via child records, rather than this record. Public Summary - 2683 This project will initiate focused acoustic research into the biology of Southern Ocean cetaceans. Deployment of sonobuoys along vessel transects will be used to survey large geographic regions for the presence and relative abundance of cetaceans. In addition, bottom mounted acoustic recording devices will permit continuous acoustic monitoring of targeted locations over long time frames. These techniques will help answer important questions regarding the presence, relative abundance, seasonality, movements, and distribution of Southern Ocean marine mammals that are necessary for effective management. Public Summary - 4102 Half a century ago the Antarctic blue whale was perilously close to extinction. Over 350,000 were killed before the remaining few were fully protected. A decade ago this elusive and poorly understood species was estimated to be less than 5% of its pre-whaling abundance. This multi-national, circumpolar project will develop and apply powerful new techniques to survey these rare whales and gain an insight into their recovery and ecology. The project is the flagship of the Southern Ocean Research Partnership - an International Whaling Commission endorsed collaborative program. Project objectives: This multi-year initiative within the AMLR program aims to implement a focused acoustic research program that will examine Southern Ocean marine mammal population dynamics through the use of technologically advanced acoustic monitoring techniques. In order to achieve the aims of this study an international collaboration has been developed leading to a multi-faceted research program. Long-term autonomous sea-floor recording devices will be utilised to conduct year-round acoustic surveys in targeted locations. Sonobuoys will additionally be used over shorter time frames to conduct strategic vessel-based acoustic surveys over large geographic ranges. These data will be used to assess distribution, movement, relative abundance, seasonality, and behaviour of cetaceans in Southern Ocean waters. These results can then be integrated with concurrently collected data on oceanographic and biological variables from vessel based surveys and remote satellite sensing leading to a larger understanding of the role of marine mammals in the Southern Ocean ecosystem. These objectives and early research design of this project are largely responsive to needs determined by the Australian Antarctic Division's recently inherited responsibilities to the International Whaling Commission. The prevailing motivation behind this project is to help develop a significant acoustic research capability in cetacean biology in order to provide sound scientific data that will assist in Australia's participation in the International Whaling Commission. Data from this project are stored offline on servers held at the Australian Antarctic Data Centre. Taken from the 2008-2009 Progress Report: Progress against objectives: Analysis of the Brokewest sonobuoy survey is complete and the manuscript has been accepted for publication in Deep Sea Research. This manuscript details the distribution of whales and seals in eastern Antarctic waters based on an acoustic sonobuoy survey. Data analysis is continuing of the recovered acoustic logger data. In addition, 1 acoustic logger was recovered during the 2008/9 season that will provide 2 years of acoustic recordings from the waters between Tasmania and the

This dataset contains estimates of krill swarm characteristics from statistical models based on underway acoustic observations along with underway and remote-sensed environmental data. Estimates of internal swarm density and depth across the study region (60-80 degrees E) are included for the time of the survey (Feb 2006). Estimates of February internal swarm density across the broader East Antarctic region (30-120 degrees E) are also included for the period 2001-2010.

This dataset contains digitized passive acoustic recordings from a hydrophone connected to an autonomous recording device both moored near the sea-floor in the Southern Ocean. Recordings were digitised at a sample rate of 500 Hz and were continuous over the period of operation. The intended purpose of these recordings was to collect baseline data on the acoustic environment (i.e. underwater sound fields). Underwater sounds that were recorded include sounds generated by Antarctic sea ice, marine mammals, and man-made sounds from ships and geo-acoustic surveys. Marine mammal sounds include calls from blue, fin, humpback, and minke whales.