967411bd-0a07-49fd-ad52-2bec65781ce7 eng utf8 dataset dataset NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom polardatacentre@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact 2025-12-18 ISO 19115 Geographic Information - Metadata ISO 19115:2003(E) European Petroleum Survey Group (EPSG) Geodetic Parameter Registry 2008-11-12 publication European Petroleum Survey Group EPSGadministrator@iogp.org https://www.epsg-registry.org/ EPSG Geodetic Parameter Dataset The EPSG Geodetic Parameter Dataset is a structured dataset of Coordinate Reference Systems and Coordinate Transformations, accessible through this online registry. information publisher urn:ogc:def:crs:EPSG::3031 6.18.3 The taxonomic composition, abundance and wet weight of macrozooplankton and micronekton captured by an RMT8 net during surveys of the Western Core Box (South Georgia), 2009-2019 2025-12-18 creation 2025-12-18 revision 2025-12-18 publication 2025-12-18 released 1.0 https://doi.org/10.5285/967411bd-0a07-49fd-ad52-2bec65781ce7 doi GB/NERC/BAS/PDC/02130 https://data.bas.ac.uk/ Please cite this item as: Stowasser, G., Fielding, S., & Tarling, G.A. (2025). The taxonomic composition, abundance and wet weight of macrozooplankton and micronekton captured by an RMT8 net during surveys of the Western Core Box (South Georgia), 2009-2019 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/967411bd-0a07-49fd-ad52-2bec65781ce7 Macrozooplankton and micronekton were collected by an RMT8 net in the waters around the island of South Georgia (Southern Ocean) during the austral summer (November to February) between 2009 and 2019 as part of the Polar Ocean Ecosystem Time Series - Western Core Box (POETS-WCB, Fielding et al. 2014) conducted by the British Antarctic Survey. Net sampling efforts took place at eight stations along paired transects spanning 133 km by 80 km over the continental shelf-break northwest of South Georgia. An 8 m2 Rectangular Midwater Trawler (RMT8) containing two opening and closing nets with 4.5 mm mesh was deployed in double oblique fashion between the surface and a maximum depth of 200 m or to within 15 m of seabed. While on the ship, contents of the net catches were identified to the lowest possible taxonomic level, enumerated and measured for their wet weight. Sub-samples were preserved in ethanol or formalin. Funding was provided by the POETS-WCB. No credit. completed Stowasser, Gabriele British Antarctic Survey Researcher author Fielding, Sophie British Antarctic Survey Researcher author Tarling, Geraint A. British Antarctic Survey Researcher author NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact asNeeded completed EARTH SCIENCE > Oceans > Marine Biology > Marine Invertebrates EARTH SCIENCE > Oceans > Marine Environment Monitoring theme Global Change Master Directory (GCMD) Science Keywords 2026-01-27 publication 23 Global Change Data Center, Science and Exploration Directorate, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA) Greenbelt MD United States of America https://earthdata.nasa.gov/about/gcmd/global-change-master-directory-gcmd-keywords Global Change Master Directory (GCMD) Keywords The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. information publisher Pelagic RMT8 Scotia Sea biodiversity biomass theme South Georgia Antarctica place Oceanographic geographical features theme GEMET - INSPIRE themes, version 1.0 2021-01-06 revision otherRestrictions no limitations to public access otherRestrictions no limitations license Open Government Licence v3.0 otherRestrictions Data are supplied under Open Government Licence v.3 otherRestrictions None. url url crossReference doi doi crossReference url url largerWorkCitation textTable eng utf8 biota environment oceans -39.62 -37.5 -53.97 -53.14 2009-12-21 2019-12-10 It is recommended that careful attention be paid to the contents of any data, and that the author be contacted with any questions regarding appropriate use. If you find any errors or omissions, please report them to polardatacentre@bas.ac.uk. NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information distributor text/csv bytes 119808 http://ramadda.data.bas.ac.uk/repository/entry/show?entryid=967411bd-0a07-49fd-ad52-2bec65781ce7 WWW:LINK-1.0-http--link Get Data Download data download dataset Methodology: Samples were collected during a series of research cruises to South Georgia between 2009 and 2020. Two ships were used: RRS James Clark Ross (9 cruises) and RRS Discovery (1 cruise). Sampling was carried out within a prescribed survey box in waters to the NW of South Georgia. Net sampling efforts took place at eight preset stations along paired transects within this box. It was not always possible to sample every one of these stations on each research cruise. An RMT8 net (Roe and Shale, 1979) was deployed and hauled in a double oblique fashion between the surface and a maximum depth of 200 m or to within 15 m of seabed. For cruise JR228, the net was deployed with an added RMT1 net (RMT8+1), but only the catches from RMT8 are considered here. RMT net catch data were recorded per each net deployment, showing all unique taxa and taxon counts, i.e. the number of individuals per each taxon in the total catch. The opening/closing trigger signal in the net-monitor log was used to determine the exact duration of each net opening and net depth. The horizontal and oblique distance and volume filtered through the net was calculated, assuming a ship speed of 2 knots and considering a nominal mouth area of 8 m2. The volume filtered value was divided into the estimated taxon counts to provide volume-specific abundance estimates (individuals m-3). This value was multiplied by the vertical depth range sampled by the net to provide a square-area abundance value (individuals m-2). Where possible, the total wet weight of each taxon within the catch was recorded using motion-compensated scales. A high-resolution scale was available on certain cruises that was capable of measuring to an accuracy of between 0.01 and 0.05 g. On other cruises, only a lower resolution scale was available with an accuracy of 1 g. On these latter cruises, weights of less than 1 g were assigned as "<1 g". Weights below the level of accuracy for high-resolution scales were assigned either "<0.01 g" or "<0.05 g". To allow an approximation of biomass (g m-3) to be made for every taxon entry, we estimated an individual weight in each of these instances as follows: <1 g = 0.5 g <0.01 g = 0.005 g <0.05 g = 0.0025 g For a small number of taxon entries, weights were not measured. In those instances, we estimated individual weight by taking the average of all other individual weights measured for that taxon. This was multiplied by the respective number of individuals within the net. Estimated individual weights were required for two taxa, as follows: Gymnoscopelus = 5.985 g Cnidaria = 9.195 g Scientific names from the taxon identifications made during the surveys were verified against the World Register of Marine Species (WoRMS) and the corresponding APHIA ID unique identification code recorded against each taxon entry. Further columns include the deployment start time (GMT), net type, geospatial coordinates, water depth and estimated volume filtered for each sampling event. Column headings are described below: Cruise - Scientific cruise name Event - Unique number of the sampling activity Net - Either net 1 or net 2 for an RMT Event_net - Concatenations of the above Station_unique_code - Concatenations of the above Net_type - Either RMT8 or RMT8+1 Survey_season - End year of austral sampling season Start_of_event - Date and time in GMT Volume_filtered (m3) - Volume of water filtered by the net Taxon - Taxonomic name AphiaID - Unique identification code according to World Register of Marine Species (WoRMS) Species_code - Code for taxon used by survey team Number_of_individuals - Total number of individuals in the net Abund (m-3) - Volume-specific abundance estimates Abund (m-2) - Square-area abundance values Data collection: Rectangular Midwater Trawler (RMT8) Data quality: Sources of variance in the dataset 1. As taxonomic analysis was carried out directly on the ship, the taxonomic level to which taxa were identified varied depending on personnel taking part in each cruise. 2. Capturing large quantities of krill or salps made it difficult to be completely thorough in quantifying other taxa in the catch. 3. It was not always possible to sample every station on every cruise, with the outermost stations in particular being difficult to sample in stormier conditions. 4. Wet weights were not always resolved to weights below 1 g depending on the availability of the high-resolution motion-compensated scale. asNeeded completed