1. Australian Antarctic Data Centre
2. Discover and Manage Data
3. Records
4. SIBEX_II_krill

Description

This dataset contains results from the Second International BIOMASS Experiment II (SIBEX II) cruise of the Nella Dan, January 1985. This cruise is the fourth cruise out of a series of six, investigating the distribution, abundance and population structure of krill Euphausia superba in the Prydz Bay region, Antarctica. SIBEX II was co-ordinated with South Africa, Japan and France, and 66 grid sampling stations covered an area from 58 degrees to 93 degrees East and from 60 degrees South to the Antarctic coast. At each sampling station, surveys of krill and other zooplankton were taken, as well as a CTD cast and water collection for phytoplankton pigment, nutrients and primary production measurement. Species identity and abundance data were obtained. The major species investigated were Euphausia superba, Euphausia frigidia, Euphausia crystallorophias and Thysanoessa marcuria. Other pteropods and cephalopods were also studied, as well as results from hydroacoustic surveys of krill biomass. Summary results are listed in the documentation.

The fields in this dataset are:

species
Station Number
Haul Type
RMT
Biomass
Weight
Flowmeter
Latitude
Longitude
Time
Date
Ice
Sea State
Density
Sea Floor
Maturity

This dataset was updated by Angela McGaffin. This download file also contains the original dataset provided in 2007. There are four files available:

SIBEX_II_krill.xls (original file)
sibex2_krill_morphometrics.xslx
sibex2_station_data.xslx
sibex2_zooplankton_corrected.xls

A minor data update took place on 202211-03 to add a scanned copy of the original acoustics log.

Quality

This cruise provides data from the fourth of six cruises, which provides a good coverage of the area over varying seasons and conditions.

Data collection: A rectangular midwater trawl net (RMT8+1) was used for the collection of larval and post larval krill Euphausia superba. 66 stations were completed. At each station, a shallow oblique haul, from 0 to 200 m, was made. At every third station a deep haul, from 0 to 1000 m, was made. Horizontal tows were also made when krill swarms were located at a particular depth, using a Simrad EK 120 echo sounder.

Onboard-ship processing: Large and fragile specimens were removed from the main catch, and all specimens were preserved in Steedman's solution. Krill catches from swarms were weighed using a clock-faced spring balance, and at least 200 species from each catch were preserved in Steedman's solution.

Post-ship processing: The RMT8 krill samples were sorted into juvenile, male and female specimens, and body length and weight were measured, using a slide caliper and Mettler top-pan balance. The males and females were classified into maturation stages according to the Makarov and Denys (1981) system. The non krill specimens in the RMT8 catches were identified according to phylum, class, sub-class or order level, and weighed. Euphausiids were identified to the following species: Euphausia crystallorophias, Euphausia frigida, Euphausia triacantha, and Thysanoessa macrura. The RMT1 samples contained a large amount of phytoplankton, which made the measurement of wet weight of the whole sample difficult. Settling volume was measured instead, by standing the samples in a 2 litre measuring cylinder for 2 weeks. Krill larvae and other Euphausiid species larvae were extracted, staged and counted under a dissecting microscope. Larvae from Euphausia superba and Euphausia crystallorophias were raised from eggs in the laboratory and used as a reference. Consistency can be established through comparison of different net methods. Oceanography and phytoplankton data were also collected at each net sampling station, so there is consistency between the oceanography and biology data. The locations of the sampling stations were based on a grid, with stations approximately every 5 degrees longitude and 1 degree latitude, over an area from 58 degrees to 93 degrees East and 60 degrees South to the Antarctic continent.

Access

These data are publicly available for download from the provided URL. A pdf copy of the referenced article is also available for download from the provided URL.

Temporal Coverages

• Start date: 1985-01-04 - Stop date: 1985-01-26

Spatial Coverages

Science Keywords

• EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > ANIMALS/VERTEBRATES > FISH
• EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > ANIMALS/INVERTEBRATES > ARTHROPODS > CRUSTACEANS
• EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > ANIMALS/INVERTEBRATES > ARTHROPODS > CRUSTACEANS
• EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > ANIMALS/INVERTEBRATES > SEGMENTED WORMS (ANNELIDS) > BRISTLE WORMS
• EARTH SCIENCE > BIOSPHERE > ECOSYSTEMS > AQUATIC ECOSYSTEMS > PLANKTON

Use Constraints

This data set conforms to the CCBY Attribution License
(http://creativecommons.org/licenses/by/4.0/).

Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=SIBEX_II_krill when using these data.