1. Australian Antarctic Data Centre
2. Discover and Manage Data
3. Records
4. AAS_4140_SIPEX_II_LOPC

Description

This dataset contains vertical profiles of particles in the upper water column (60 m depth) at six sites. A laser optical plankton counter (LOPC) was deployed through a hole in the sea ice, or from the stern of the Aurora Australis, and lowered to 60 m, logging as it was lowered. The LOPC records particles in the size range 100 um to 20 mm, though the small aperture (7 cm x 7 cm) means that the largest particles are probably only sampled rarely.
For each site, the data are presented as normalised biomass for a series of equivalent spherical diameters (ESD). ESD is based on measurements of length and width of animals likely to be sampled via the LOPC (i.e. animals that are sampled at the same time with a traditional plankton net).

The data were collected on the SIPEX II voyage of the Aurora Australis, from 14/9/2012 to 16/11/2012. Sites were all located in first year pack ice; the ship would nudge up to a floe and then samples of ice, zooplankton, etc. were collected directly by working on the floe. The LOPC was either deployed through a large hole in the pack ice, or it was deployed off the stern of the AA. Method of deployment did not really have an impact on the data collected, it was more a logistical decision based on conditions.

Purpose

The data can be used to compare biomass size spectra within and between aquatic environments. It was deployed for the first time in ice-covered waters during this project. It provides a baseline against which we could assess changes to the Southern Ocean environment in the future.

Quality

The problems associated with the dataset were related to some difficulties in deployment. Ice particles and clumps in surface waters were sampled by the LOPC as it was lowered and these needed to be removed from the dataset during post-deployment analysis.

The dataset contains only data from sites 3-8. Sites 1-2 were "pilot" sites only for testing the LOPC and making sure it was functioning correctly.

Access

These data are publicly available for download from the provided URL.

Temporal Coverages

• Start date: 2012-09-01 - Stop date: 2012-10-31

Spatial Coverages

Data Resolution

Science Keywords

• EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > PROTISTS > PLANKTON
• EARTH SCIENCE > BIOSPHERE > ECOSYSTEMS > AQUATIC ECOSYSTEMS > PLANKTON

Use Constraints

There are no constraints to using this dataset. Users might like to contact Dr Jason Everett (University of New South Wales), who is compiling a global size-spectra dataset based on the LOPC.

Some of these data are published in Wallis, J.R., Swadling, K.M., Everett J.D., Suthers, I.M., Jones, H.J., Buchanan, P.J., Crawford, C.M., James, L.C., Johnson, R., Meiners, K.M., Virtue, P., Westwood, K., and Kawaguchi, S. (2015) Zooplankton abundance and biomass size spectra in the East Antarctic sea ice zone during the winter-spring transition. Deep-Sea Research II 131: 170-181

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=AAS_4140_SIPEX_II_LOPC when using these data.