zodtrawl - Palmer LTER, krill collections

0001pal

<DATE_RANGE> dates of collection activity: 10 Nov 2000 to 7 Jan 2001 and 31 Jan to 6 Mar 2001.

Measurements of the length frequency distributions and condition factor measurements of the krill populations in the Palmer Basin region yield information on seasonal changes in the demographics of the krill population (on/offshore movements) and in the physiological condition of the krill. In conjunction with the bioacoustics determinations of biomass the data characterize the abundance and size character of krill in this nearshore region throughout the season. Krill are collected for these measurements by SCUBA divers and with a net towed from a zodiac. Zodiac trawls and dive operations are conducted in the immediate Palmer area within 3.7 km of the station (Palmer grid; Waters and Smith, 1992.) This data set contains a record of dives, zodiac trawls and dip nets to collect krill, and what was done with the catch.

The following variables are recorded: Event, Tow or Dip net No., Location, Month, Day, Time begin (GMT), Julian Day, Comments that include IGR experiment number, other used and other species in catch etc.)

<DERIVED_VARIABLES> none

<SAMPLING_FREQUENCY> The planned sampling is for weekly collections of Antarctic krill, with length frequency determinations from growth rate experiments every 10-14 d, condition factor determinations for AC0 krill every two weeks, and samples for chemical composition three times a season. Nets were deployed with a winch and A-frame from a Mark V zodiac, the Rubber Duke. For all zooplankton tows, a 1-m diameter, 500-µm mesh ring net with a cod end with 335 µm mesh was deployed. A targetted tow was performed when a krill school was detected with the 50 kHz furuno echosounder or the BioSonics Model 102 on board the Rubber Duke. Once the cod end was retrieved, krill to be used for live experiments were placed in several seawater-filled buckets or coolers, keeping densities as low as possible.

<EXPERIMENTAL_DESIGN> Although tAlthoughe 0001pal season had diving operations, krill were collected with net tows from the Rubber Duke. Ten IGR experiments were conducted between 10 November 2000 and 2 March 2001. Six sets of young of the year (yoy) were taken for condition factor (carbon per length cubed) between 10 November and 27 December 2000. Two collections of all size ranges available were frozen in the austral spring for archival. Post cruise, krill were scarce within the boating area.

<FILE_FORMAT> ascii, comma separated variables

<STORAGE_LOCATION> http://www.icess.ucsb.edu/lter ~lter/data/0001pal/zodtrawl/

<FILE_NAMES> zodtrawl.list

<PRINCIPAL_INVESTIGATORS> Robin M. Ross, Langdon B. Quetin

<ASSOCIATE_INVESTIGATORS> none

<CONTACT_PERSON> Robin M. Ross, Langdon B. Quetin Marine Science Institute University of California at Santa Barbara Santa Barbara, CA 93106 robin@icess.ucsb.edu, langdon@icess.ucsb.edu

<SAMPLES_COLLECTED_BY> LB Quetin, DL Martin, SA Oakes, C Holmes, JT Watson, RM Ross

<LAB_ANALYSIS_BY> above

<DATA_ENTRY_BY> DL Martin, RM Ross

<DATA_ANALYSIS_BY>

<SUBMITTED_BY> RM Ross

<DATE_SUBMITTED> 7 July, 2003

<DATES_UPDATED>

<SUPPORTING_DOCUMENTS> Waters, K. J. and R. C. Smith, 1992. "Palmer LTER: A Sampling Grid for the Palmer LTER Program." Antarctic Journal of the United States 1992.

<QUALITY_ASSURANCE>

<DATA_REQUESTED_BY>

Top of Form 1 Datafile Form V1.2 for describing a data file.