Southern Ocean Continuous Zooplankton Records
Entry ID:
AADC-00099
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Summary
This dataset contains results from Continuous Plankton Recorder (CPR) surveys in the Southern Ocean. When the opportunity arises, zooplankton species, numbers and abundance data are recorded on a continuous basis as vessels steam through the area between Australia and Antarctica, including Heard and Macquarie Islands. Observations have been made since June 1990 and are ongoing. Obviously ... the observations are not continuous over the region with time.
The fields in this dataset are:
Tow Number
Ship Code
Time (UTC)
Date
Month
Year
Season
Latitude
Longitude
Segment Number
Distance (nautical miles)
Segment Length
Species
Abundance
Fluorescence
Salinity
Temperature
LICOR
A detailed description of the fields in the dataset is as follows:
Ship Code
Two letter code which defines the ship used.
AA - Aurora Australis
HM - Hakuho Maru
KM - Kaiyo Maru
SH - Shirase
TA - Tangaroa
UM - Umitaka Maru (no data yet)
Time
Time of segment sample in GMT (UTC).
Date
Date of segment sample in GMT (UTC).
Month
A useful field to allow searches by month and for comparison between months, and also the same month between years.
Year
Another useful field to search for individual years for comparison between years.
Season
Similar to the Year field, but allows search for data from a particular Antarctic season, based around the austral summer, i.e. the 2002/03 season.
Latitude
Decimal latitude.
Longitude
Decimal longitude.
Segment No.
Individual segment number for each tow, and renumbered for each tow. This field is probably only of value in checking data in the database against the original laboratory counts.
Dist. Nm
The end of each sampling segment is geocoded with latitude and longitude calculated from the one minute time-stamped GPS data. "Dist. Nm" is distance in nautical miles between each segment, which is calculated as the cumulative distance between each 1 minute interval. In theory each segment should be 5 nautical miles exactly but the calculations from the 1 minute intervals is not that accurate, hence the next field "Segment Length". Variation in "Dist. Nm" between segments for a particular tow is thus a calculation artefact. If 10 sec time stamped intervals were used for CPR geocoding program then calculations of "Dist. Nm" would be almost exactly 5 miles with little variation between segments.
Segment length
This is the true segment length as used in the Geocoding program used to cut the silk, and to calculate positions and average environmental data for each segment. In theory, all segments are 5 nautical miles long. However, this wasn't always the case with early Aurora Australis tows, where it was assumed that each marked segment was 5 nautical miles whereas each tow had subtle variations in silk advancement, depending on the wear of the cassette or travel with or against a current. True segment length has since been recalculated. At other times, some silks have been incorrectly cut and the true length has again been recalculated. The last segment of each tow may be less than 5 nautical miles. This field can be used to standardise species counts to say 5 nautical miles or to a theoretical volume filtered by multiplying the distance travelled by aperture area (12.5 x 12.5 mm).
Volume Filtered = Distance (n miles) x 1852 metres x 0.0125 m2.
A 5 nautical mile segment theoretical represents 1.45 m3.
Species data
Zooplankton have been identified to lowest possible taxon, usually species, and counted for each segment. For copepods, copepodites and for some species nauplii (e.g. Rhincalanus gigas) have been counted separately, and for euphausiids, naupliar, calyptopis and furcilia developmental stages are identified. "Total Abundance" of all zooplankton in a segment has been included as a data field.
Environmental Data
The last four fields are the averaged environmental data for each segment. Three fields, fluorometry, salinity and sea water temperature are common to all research vessels used to date. Note: there doesn't seem to be any fluorometry data for Hakuho Maru. The fourth field is light as PAR, which was recorded on all vessels except Shirase, but has been included as a useful parameter to help select data from night and day. Caution: Fluorometry is measured differently on each vessel and are thus not directly comparable between vessels. On Aurora Australis the fluorometry value is arbitrary, although the fluorometer is routinely calibrated. On Tangaroa and Kaiyo Maru, fluorometry has been expressed as a concentration of chlorophyll a. Salinity on AA has been calculated by thermosalinograph. Temperature on AA is measured by a high resolution thyristor near the entrance of a dedicated seawater line, to avoid the problems of heating of the water in by the ship as it passes through pipes. Again the data may not be fully comparable with other vessels. Light as PAR is recorded as micro-Einsteins m-1 s-1.
Related URL
Link:
GET DATA
Description:
Download point for the full dataset - authorised users only
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Geographic Coverage
Spatial coordinates
| N: -44.0 |
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S: -70.0 |
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E: 150.0 |
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W: -90.0 |
Temporal Coverage
Location Keywords
Science Keywords
ISO Topic Category
Platform
Instrument
Project
Quality
Caution: Fluorometry is measured differently on each vessel and are thus not directly comparable between vessels. See the summary for further details.
The end of each sampling segment is geocoded with latitude and longitude calculated from the one minute time-stamped GPS data. "Dist. Nm" is distance in nautical miles between each segment, which is calculated as the cumulative ... distance between each 1 minute interval. In theory each segment should be 5 nautical miles exactly but the calculations from the 1 minute intervals is not that accurate, hence the next field "Segment Length". Variation in "Dist. Nm" between segments for a particular tow is thus a calculation artefact. If 10 sec time stamped intervals were used for CPR geocoding program then calculations of "Dist. Nm" would be almost exactly 5 miles with little variation between segments.
In theory, all segments are 5 nautical miles long. However, this wasn't always the case with early Aurora Australis tows, where it was assumed that each marked segment was 5 nautical miles whereas each tow had subtle variations in silk advancement, depending on the wear of the cassette or travel with or against a current. True segment length has since been recalculated. At other times, some silks have been incorrectly cut and the true length has again been recalculated. The last segment of each tow may be less than 5 nautical miles. This field can be used to standardise species counts to say 5 nautical miles or to a theoretical volume filtered by multiplying the distance travelled by aperture area (12.5 x 12.5 mm).
Access Constraints
The full file of CPR data are restricted to authorised users only. If you would like information on whether it is possible to become an authorised user, contact the investigator.
Currently, a summary file of voyages that CPR's were deployed is available for download.
Presence records of known species (with no abundance value) are published via DiGIR web services to SCAR-MarBIN, OBIS and GBIF data portals.
Use the download link below to a web page showing voyages, maps of tracks and species distribution maps of the area between Australia and Antarctica.
Use Constraints
Please follow instructions listed in the citation reference provided at the URL below when using these data.
Ancillary Keywords
Data Set Progress
Originating Center
Data Center
Distribution
Distribution Media:
HTTP
Distribution Size:
1323 kb
Distribution Format:
excel
Fees:
free
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Personnel
GRAHAM
HOSIE
Role:
TECHNICAL CONTACT
Role:
DIF AUTHOR
Role:
INVESTIGATOR
Phone:
+61 3 6232 3364
Fax:
+61 3 6232 3158
Email:
graham.hosie at aad.gov.au
Contact Address:
Australian Antarctic Division
203 Channel Highway
City:
Kingston
Province or State:
Tasmania
Postal Code:
7050
Country:
Australia
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Creation and Review Dates
DIF Creation Date:
1999-10-07
Last DIF Revision Date:
2009-01-21
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