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.
Many of the original CPR logbooks from the various voyages have also been scanned, and are available via the Australian Antarctic Data Centre's Reports Register.
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.
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 (Flu_Value), salinity (TSG_Sal) and sea water temperature (W_Temp_Hi) 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 (LICOR), 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.
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. "Segment Length" is the distance in nautical miles for each segment, which is calculated as the cumulative ... distance between each 1 minute interval. In theory, all segments are 5 nautical miles long. However, this wasn't always the case with early RSV Aurora Australis tows, where it was assumed that the silks advanced at a predetermined rate of 1 cm per nautical mile, whereas each tow had subtle variations in silk advancement, depending on local condition, e.g. whether the CPR was travelling 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 is rarely exactly 5 nautical miles. It is usually less. In this situation we apply the following rule: if the last segment is longer than 2.5 nautical miles it remains as a segment in its own right and can be between 2.5 and 4.99 nautical miles, whereas if it is less than 2.5 it is added to the penultimate segment making the last segment 5 to 7.49 nautical miles. Users of the data can elect to dismiss the last segment. The "Segment Length" field can be used to standardise species counts. Dividing abundance values by the respective segment length will produce numbers per nautical mile, which is equivalent to 0.3 cubic metres based on 1 nautical mile being 1852 m multiplied by aperture area (12.7 x 12.7 mm). A 5 nautical segment is equivalent to 1.5 cubic metres.
Notes on salinity:
The salinity measurement comes from the various thermosalinograph units mounted in the underway systems of the ships.
The value is a standard salinity measurement. For older voyages, it was recorded as parts per thousand defined as a the amount of salt in a unit of water. Standard Seawater was 35 ppt. For more recent voyages, the unit was dropped, and salinity is just referred to as a number (eg 35).
Further notes on fluorometry:
Most values come from Turner fluorometers, the Aurora Australis has a Turner TD10, and the units are arbitrary. Further, a value of 200 on one voyage is not necessarily the same as 200 on another voyage, even with daily calibration and cleaning of the sensor. The fluorometry values are really only of value within a voyage in as much that 200 is double the fluorescence activity of 100.
The data are available for download from the provided URL.
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.
Scanned ... copies of many CPR logbooks are also available for download from the provided URL.
In addition to the AADC data are held in the Global Alliance of CPR Surveys (GACS) Database and the IMOS Data Portal. Presence records of known species (with no abundance value) are published via DiGIR web services to SCAR-MarBIN, OBIS and GBIF data portals.
Please contact the investigators before using these data, as some explanation may be required.
Please contact the investigators before using these data, as some explanation may be required. ... These data were sourced from the Scientific Committee on Antarctic Research (SCAR) sponsored Southern Ocean CPR (SO-CPR) Survey Database, hosted by the Australian Antarctic Data Centre (AADC). The AADC is part of the Australian Antarctic Division (AAD, a division of the Department of Sustainability, Environment, Water, Population and Communities (SEWPaC)). The SO-CPR Survey and database are also funded, supported and populated by the Australian Government through the SEWPaC-AAD approved AAS project 4107 and the Integrated Marine Observing System (IMOS) funded by the Australian Government National Collaborative Research Infrastructure Strategy and the Super Science Initiative, the Japanese National Institute of Polar Research (NIPR), the NZ National Institute of Water and Atmospheric Research (NIWA), the German Alfred Wegener Institute (AWI), the United States of America - Antarctic Marine Living Resources programme (NOAA US-AMLR), the Russian Arctic and Antarctic Research Institute (AARI), the Brazilian Programa Antartico Brasileiro (PROANTAR), the Chilean Instituto Antartico Chileno (INACH), the South African Departmental of Environmental Affairs (DEA) and the French Institut polaire francais - Paul-Emile Victor (IPEV) and Universite Pierre-et-Marie-Curie (UPMC).