Scientific echosounder data provide a predator’s view of Antarctic krill (Euphausia superba)

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-ddPing_time - format hh:mm:ssPing_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 metadataall_transects.csv    (file size: 14.8 K)This is the transect metadata for both the KACTAS and KAOS surveys:Transect - transect numberstartDate - start date of transect dd/mm/yyyystartTime - start time of transect hh:mmendDate - end date of transect dd/mm/yyyyendTime - end time of transect dd/mm/yyyyPing_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 observedSurvey - Either KACTAS or KAOSLeg - 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/yyyyGPS_time - HH:MM:SSGPS_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 1y - relative grid position (y) used for plotting Figure 1Survey - either: KACTAS_Krillbox, KAOS_Krillbox1, or KACTAS_Krillbox2Krill swarms for both the KACTAS and KAOS surveysKACTASandKAOSswarms.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 surveyKACTAS-survey.EV        (21.8 MB)An Echoview file (version 12.0) for the KACTAS acoustic data analysisKACTAS EK60 scientific echosounder calibration valuesKACTAS_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 surveyKAOS-survey.EV    (16.4MB)An Echoview file (version 12.0) for the KAOS acoustic data analysisKAOS EK60 scientific echosounder calibration valuesKAOS_EK60_calibration.ecs    5,711    01/11/2021 04:36    -a–An Echoview format calibration file for the KAOS survey (see Table 3 for calibration values and Demer et al. (2015) for a description of the calibration parameters).