bioacoustics 9697pal 11 Nov 96 to 27 Mar 97 on station; acoustic transects from 23 Nov to 21 Mar Continuous acoustic data was collected from two standard transects within the Palmer LTER nearshore study area. A. An event_bld.list gives details of time and location for all acoustic transects, with links to the rest of the data collected through the event number. The ten variables in the event- bld.list are: Event.number Start.time (GMT) End.time (GMT) Start.Date (mmddyy GMT) Stations at beginning and end of transect Start.Latitude (°S) Start.Longitude (°W) End.Latitude (°S) End.Longitude (°W) Transect distance (m) The transect distance is calculated from latitudes and longitudes taken at ~ 10 minute intervals during the transect. The transects are slightly curved and the distance cannot be calculated from the beginning and end latitude and longitude B. The calibration files give the calibration constants: Variables are: BeamPatternFactor Rcvr1_G120logR Rcvr1_G140logR Rcvr2_G120logR Rcvr2_G140logR Rcvr3_G120logR SrcLevel_at0dB SrcLevel_at-3dB SrcLevel_at-6dB SrcLevel_at-10dB SrcLevel_at-13dB 20/40CrossoverPt There were a total of 21 acoustic files for 9697pal. The two Palmer nearshore transects (Pal J-F and Pal A-E) were each done weekly when weather permitted. The Palmer LTER uses Biosonics equipment and software to collect hydroacoustic data, and to do the preliminary processing on board. (1) collection of data The acoustic system consists of a BioSonics Model 102 echo sounder connected to a downward looking 120 kHz transducer which was deployed with a tow body several meters below the surface. The towbody was deployed from a Mark V zodiac. The sounder was operated with a 20 log R (R = range in m) time-varied-gain (TVG) function to compensaate for one-way acoustic spreading loss. (2) archival process The analog voltage signals received by the echosounder are processed in the field through an interface tape unit which records a digitized version of each signal onto a digital audio tape (DAT) recorder. The DAT tapes can be replayed with the Biosonics Echo Signal Processing (ESP) software package for calculation of Sum Squared Voltage (SSV) data if a file is lost or if a different configuration file is desired. (3) primary processing of data: Echo integration of the returned acoustic energy (volts) was done with the BioSonics Model 221 Echo Signal Processor, and ESP version 3 on a Dec 486 computer on board. The system was configured to integrate voltage measurements over 2-m depth intervals and several pings. These integrated values were used to generate a two-dimensional (alongtrack, vertical) matrix of volume scattering data (VSD, m3 m-3) for each acoustic transect, according to algorithms described in Apprendix C of BioSonics. When in deep water (>200 m) data was collected without a bottom algorithm. In shallow water, a bottom algorithm was used to automatically separate the bottom and biotic signal. (4) calibration of the system was done by BioSonics ( Seattle, WA) in a tank at ambient temperature. The calibrations bracketing the use of the equipment were done in May 1996 and August 7 and September12, 1997. The calibration files done in Aug/Sep 1997 were closest in time to use of the equipment and are recommended for use. During 9697pal, the OldDeck cable was used exclusively. The Deck cables are 100' long. - Old Deck (S/N#141-92-740) Acoustic transects on a weekly basis show seasonal trends in acoustic biomass, and in the size and distribution of aggregations. Antarctic krill are usually the dominant sound scatterer in the Palmer LTER region, but during the latter part of 9697pal salps were also present. bioacoustics, antarctic krill, palmer lter 1) event_bld.list ascii, comma separated (number of columns)! 9697pal and identifying information rows with column headers and the units of the parameter data follow 2) calibration file ascii, space delimited 3) VSD acoustic matrix for each event binary file with results from echo integration of the voltage returning to the echo sounder. the data stored is mean voltage squared for each depth strata and ping. The event_bld.list and calibration file are in: ~lter/data/9697pal/bioacoustics Velella on the MSILTER Apple talk network The VSD files are stored on a hard disk off line until room is available on line. They may be accessed by contacting Karen Baker, data manager for the Palmer LTER. (1) event_bld.list (2) acoCalib.970912OldDeckOldTow; acoCalib.970807OldDeckNewTow files named: acoCalib.(date of calibration)(cable combination) (3) rawdata/(event#).dat the VSD acoustic matrix for each transect is named by the event. Robin M. Ross, Langdon B. Quetin none Robin M. Ross, Langdon B. Quetin JL Jones, D Conlin, CT Shaw JL Jones JL Jones, RM Ross JLJones, RM Ross rawdata in May 1997 event_bld.list, acoCalib files and documentation 23June 1999 BioSonics (1990) BioSonics Echo Signal Processor Operators Manual. BioSonics, Inc., Seattle, WA, 373 pp. Lascara (1996) Seasonal and mesoscale variability in the distribution of Antarctic krill, Euphausia superba, west of the Antarctic Peninsula. Ph. D. Thesis, Old Dominion University. 167 pp. Greene, C. H., T. K. Stanton, P. H. Wiebe and S. McClatchie (1991) Acoustic estimates of Antarctic krill. Nature 349: 110. Nero, R. W. and J. J. Magnuson (1989) Characterization of patches along transects using high resolution 70 kHz integrated acoustic data. Canadian Journal of Fisheries and Aquatic Sciences 46: 2056-2064. Wiebe, P. H., C. H. Greene, T. K. Stanton and J. Burczynski (1990) Sound scattering by live zooplankton and micronekton: empirical studies with a dual-beam acoustical system. Journal of Acoustical Society of America 88: 2346-2360.

Datafile Form V1.2 for describing a data file.