bioacoustics 9798pal 13 Nov 97 to 4 Apr 98 on station; acoustic transects from 5 Dec 97 to 23 Mar 98 Continuous acoustic data from two standard transects within the Palmer LTER nearshore study area A.An event_bld.lis 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.numberStart.tEnd.time (GMT)Start.Date (mmddyy GMT)FlagGrid(Palmer LTER grid location)Start.Latitude (°S) Start.Longitude (°W)End.Latitude (°S) as calculated from total transect distance, start latitude and longitude, and end longitudeEnd.Longitude (°W) Transect Distance (km)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 longitudeStation IDs Start and End of transect B. The calibration files give the calibration constants:Variables are: BeamPattern,FactorRcvr1_G120,logRRcvr1_G140,logRRcvr2_G120,logRR cvr2_G140,logRRcvr3_G120,logRSrcLevel_at0dB,SrcLevel_at-3dB,SrcLevel_at-6dB,SrcLevel_at-10dB,SrcLevel_at-13dB20/40CrossoverPt There were a total of 27 acoustic files for 9798pal. The two Palmer nearshore transects (Pal J-F and Pal A-E) were each done weekly when weather permitted except during the annual cruise when transects were done from the research vessel (98janpal). Two were done from the AbelJ (24 Jan), and one from the Laurence M. Gould (13 Feb).The Palmer LTER uses Biosonics equipment and software to collect hydroacoustic data, and to do the preliminary processing on board. (1) collection of dataThe 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 (27 transects) or the research vessel (3 transects). 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 processThe 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 August 7 and September 12, 1997 and July 30, 1998. The calibration files done in Aug/Sep 1997 were closest in time to use of the equipment and are recommended for use. During 9798pal, the 92Deck cable was used exclusively for the zodiac transects. The combination of 92 Deck 94 Tow was used for the research vessel transects. The Deck cables are 100' long.- 92 Deck (S/N#141-92-740) - 94 Tow (S/N#147-94-156) Acoustic transects on a week ly basis show seasonal trends in acoustic biomass, and in the size, distribution , depth and density of aggregations. Antarctic krill are usually the dominant sound scatterer in the Palmer LTER region. bioacoustics, antarctic krill, palmer lter 1) event_bld.listascii, comma separated(number of columns)! 9798pal and identifying informationrows with column headers and the units of the parameter data follow2) calibration fileascii, space delimited3) VSD acoustic matrix for each eventbinary 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/9798pal/bioacousticsVelella on the MSILTER Apple talk networkThe 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.listThere are two files, one for the zodiac operations (event.bld_list9798) and one for the transects from the research vessels (event.bld_list98janpal).(2) acoCalib.97080792Deck; acoCalib.98073092Deck; acoCalib.970807OldDeckNewTow; acoCalib.980730OldDeckNewTowfiles named: acoCalib.(date of calibration yymmdd)(cable combination)(3) rawdata/(event#).datthe VSD acoustic matrix for each transect is named by the event. Robin M. Ross, Langdon B. Quetin none Robin M. Ross, Langdon B. Quetin LBQuetin, JL Jones, D Conlin, CT Shaw, J Kneebone JL Jones JL Jones, RM Ross JLJones, RM Ross rawdata uploaded throughout the season, from Dec 97 through Mar 98event_bld.list, acoCalib files and documentation 31 May 2000 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.