bioacoustics 9899pal 10 Nov to 22 Dec 1998, and 14 Feb to 12 Mar 99 on station; acoustic transects from LMG: 8 Jan to 12 Feb 1999 acoustic transects from zodiac: 16 Feb 99 to 6 Mar 1999 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) Flag Grid(Palmer LTER grid location) Start.Latitude (°S) Start.Longitude (°W) End.Latitude (°S) End.Longitude (°W) The transect distance is not the distance between the start and end latitudes and longitudes because the transects are slightly curved. The Palmer LTER grid location is calculated from the average latitude and longitude of the transect. 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 Weekly runs of the two Palmer nearshore transects (Pal J-F and Pal A-E) were planned from mid-November to mid-March, weather and ice conditions permitting, except during the annual cruise when transects were done from the research vessel (99janpal). However during the austral spring, ice cover prevented zodiac operations and no acoustic data are available from November and December 1998. There were a total of 7 acoustic transects run from the zodiac for 9899pal, at weekly intervals from 14 Feb to 6 Mar, three times each for A-E and F-J; a partial transect (I-G) was run once due to ice and weather conditions. The transects were run at the beginning, in the middle and at the end of the 99Jan cruise on the LMG (8&9 Jan, 23 Jan (3), 11&12 Feb) for a total of 7 transects, three for A-E and four for F-J. The Palmer LTER uses Biosonics equipment and software to collect hydroacoustic data, and to do the preliminary processing on board during collection. (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 1 (zodiac) or 2 (LMG) meters below the surface . The towbody was deployed from a Mark V zodiac (7 transects) or the research vessel (7 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 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 on July 30, 1998 and August 3, 1999. There were only small differences in the calibrations. During 99Jan, the NewDeck/NewTow cable combination was used exclusively. During 9899pal, the 94Deck cable was used exclusively for the zodiac transects. The Deck cables are 100' long, the Tow cables 218' long - New Deck (S/N#141-94-870) - New Tow (S/N#147-94-156) - Old Deck (S/N#141-92-740) - Old Tow (S/N#147-92-137) Acoustic transects on a weekly 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.list ascii, comma separated (number of columns)! 9899pal 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/9899pal/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 There are two files, one for the zodiac operations (event.bld_list9899) and one for the transects from the research vessels (event.bld_list99janpal). (2) acoCalib.97080792Deck; acoCalib.98073092Deck; acoCalib.970807OldDeckNewTow; acoCalib.980730OldDeckNewTow files named: acoCalib.(date of calibration yymmdd)(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 Daniel Martin 10 Nov ­ 22 Dec Langdon Quetin 10 Nov ­ 22 Dec Caroline T. Shaw 14 Feb ­ 12 Mar Justin B. Smith 14 Feb ­ 12 Mar On cruise: RM Ross, CT Shaw, JB Smith, L Coe, K Grimm, J Kneebone RM Ross RM Ross rawdata, event_bld.list, acoCalib files and documentation 4 June, 2001 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.