KRILLBASE is a data rescue and compilation project which aims to improve the availability of information on two of the Southern Ocean''s most important zooplankton taxa: Antarctic krill (Euphausia superba) and salps (Family Salpidae). In 2016, the project released a database of information from 15,194 scientific net hauls, collected between 1926 and 2016 by scientists from ten countries. These data, on the density of Antarctic krill and salps, provide a resource for analysing the distribution and abundance of these taxa throughout the Southern Ocean, to support ecological and biogeochemical research as well as fisheries management and conservation. The data are available as a downloadable csv files and via a seachable web interface. Each row of the main data table represents either a net haul or a composite of several net hauls. The columns describe searchable and filterable sampling and environmental information as well as the krill and salp density. The krill data are presented as both the observed density (NUMBER_OF_KRILL_UNDER_1M2, no.m-2) and the density standardised to a single, relatively efficient sampling method (STANDARDISED_KRILL_UNDER_1M2, no.m-2). The salp data are presented as observed density for all species combined, where an individual can be either a solitary oozoid or a member of an aggregate chain (NUMBER_OF_SALPS_UNDER_1M2, no.m-2). 12,758 of the net hauls in the database include krill data, 9,726 include salp data. 7,295 of the net hauls include both krill and salp data. For hauls where data for either salps or krill were not available the relevant field is blank. The RECORD_TYPE column distinguishes between four types of record and we emphasise that every analysis of the data should first screen on this field to avoid using the same data twice. Most records are labelled "haul", and these result from a single net sampling the water column at a specific station. Others, labelled "stratified pooled haul", are the combined result of several (typically three) stratified hauls (labelled "stratified haul") sampling different parts of the water column. A small number of records, labelled "survey mean" represent the arithmetic mean densities from multiple stations as this was the only recoverable information from the relevant surveys, which were mainly conducted in the 1980s. The dataset is fully described in the following publication which should be cited in published analyses of these data: Atkinson A, Hill SL, Pakhomov E, Siegel V, Anadon R, Chiba S, Daly KL, Downie R, Fielding S, Fretwell P, Gerrish L, Hosie GW, Jessopp MJ, Kawaguchi S, Krafft BA, Loeb V, Nishikawa J, Peat HJ, Reiss CS, Ross RM, Langdon B Quetin, Schmidt K, Steinberg DK, Subramaniam RC, Tarling GA, Ward P (2017) KRILLBASE: a circumpolar database of Antarctic krill and salp numerical densities, 1926-2016. Earth Syst. Sci. Data, 9: 193-210 (doi:10.5194/essd-9-193-2017)
Acoustic backscatter data were collected on board the RRS James Clark Ross (cruise JR177) as part of the Discovery 2010 programme. Data were collected using a Simrad EK60 echo sounder at 38, 120 and 200 kHz. The EK60 was run continuously from Stanley (Falkland Islands) to Signy (South Orkney Islands), then to South Georgia across the Scotia Sea in the austral summer from December 2007 - February 2008. Dedicated acoustic transects were also run at a number of stations within these transects. The EK60 was calibrated during JR177 (10-11th February 2008). More information about the calibration can be found in the Cruise Report for JR177: https://www.bodc.ac.uk/data/information_and_inventories/cruise_inventory/report/jr177.pdf JR177 was the second of three cruises which comprise the field studies of the British Antarctic Survey''s (BAS) core science Discovery 2010 programme, funded by the Natural Environment Research Council.
Acoustic backscatter data were collected on board the RRS James Clark Ross (cruise JR179) as part of the BIOFLAME-BIOPEARL programme. Data were collected using a Simrad EK60 echo sounder. Data were collected throughout the cruise which ran through the Drake Passage, Bellingshausen Sea and Amundsen Sea in the Southern Ocean, from February to April 2008. The raw data files (Simrad .raw format) are held by the Polar Data Centre (PDC) at the British Antarctic Survey (BAS).
Acoustic backscatter data were collected on board the RRS James Clark Ross (cruise JR161) as part of the Discovery 2010 programme. Data were collected using a Simrad EK60 echo sounder at 38, 120 and 200 kHz. The EK60 was run continuously from Stanley (Falkland Islands) to Signy (South Orkney Islands), then to South Georgia across the Scotia Sea in the austral spring (October - December) of 2006. Dedicated acoustic transects were also run at eight stations within these transects. The EK60 was calibrated prior to data collection on a previous cruise (JR159 on 13-14th October 2006). More information about the calibration can be found in the Cruise Report for JR159: https://www.bodc.ac.uk/data/information_and_inventories/cruise_inventory/report/jr152_jr159.pdf JR161 was the first of three cruises which comprise the field studies of the British Antarctic Survey''s (BAS) core science Discovery 2010 programme, funded by the Natural Environment Research Council.
Acoustic backscatter data were collected on board the RRS James Clark Ross (cruise JR200) as part of the Discovery 2010 programme. Data were collected using a Simrad EK60 echo sounder. This cruise ran two transects (Stanley to Signy and Signy to South Georgia) across the Scotia Sea in the austral autumn (March - April) of 2009. Within these transects, there were a series of stations at which dedicated acoustic transects were run, although the EK60 was run continuously throughout the cruise. JR200 was the third of three cruises which comprise the field studies of the Discovery 2010 programme. The programme was designed to analyse interactions in the Southern Ocean ecosystem. The raw data files (Simrad .raw format) are held by the Polar Data Centre (PDC) at the British Antarctic Survey (BAS).
This dataset contains data from a study of pteropod shell dissolution on individuals exposed to CO2-enriched seawater. The data include the amount of dissolution as well as the physical and chemical parameters on which carbonate chemistry parameters were calculated.
The KRILLBASE-length frequency database comprises individual length measurements of 613487 Euphausia superba from 6470 scientific net hauls. Some of these individually-measured krill have additional information on their sex and maturity stage. Most of these E. superba are postlarvae, but some of the hauls include small (< 20 mm) krill which likely include furcilia larvae as well as juveniles. Much of these data were compiled at British Antarctic Survey in 2007 by Mark Jessopp, with additional compilation by Angus Atkinson, Catherine Brewster and Natalie Ensor, and later data checking by Angus Atkinson with Helen Peat. The circumpolar distribution of records is illustrated in the file KRILLBASE_LF_DISTRIBUTION that is available along with this dataset. Examples of uses of KRILLBASE-length frequency are in Atkinson et al. (2009), Tarling et al. (2016), Perry et al. (2019) and Atkinson et al. (2019). The KRILLBASE-length frequency records were provided by contributing authors of the database or transcribed from the literature or from other institutional databases. At the time of data compilation, data from commercial-size large mesh trawls and from the commercial fishery was also transcribed, providing valuable information on the larger krill caught by these nets. These data are not included in this current KRILLBASE-length frequency database version, because of the difficulty in comparing them with the finer mesh scientific nets compiled here, and because length and population structure are also available in more complete form from CCAMLR. The KRILLBASE-length frequency database forms a complementary database to the KRILLBASE-abundance database (doi:10.5285/8b00a915-94e3-4a04-a903-dd4956346439), which compiles the abundance of Euphausia superba and salps in the Southern Ocean (Atkinson et al 2017). Both databases are multi-national, circumpolar compilations of net samples spanning years 1926 to 2016. The KRILLBASE-length frequency database uses some of the stations as KRILLBASE-abundance but also additional ones from targeted hauls or horizontal hauls.
Sediment cores were taken using a box corer. The sediment was subsampled using a 20 x 20 x 12 cm and incubated for 12 days. At the end of incubation, the macrofauna retained (500 um sieved) from each aquarium were fixed in 10% phosphate buffered formalin (4% formaldehyde) and stored in sealed plastic buckets for a minimum of three months. Prior to identification samples were rinsed and preserved in 70% industrial methylated spirit (IMS). Using a stereo microscope, all the animals were picked out of the residue, stored in vials containing 70% IMS, and identified to the lowest possible taxon with abundance and biomass per taxon noted. Biomass was obtained using blotted wet weight (+/- 0.0001g). The individual numbers of each taxa were counted to give abundance data. This was determined by the presence of a head in cases where specimens had been damaged. Any badly damaged specimens or parts of specimens where no head was present were separated into major group debris (annelid, mollusc and crustacea) pots and their presence noted as YES/NO for abundance). All molluscs were weighed inclusive of shells, tube dwelling polychaetes were weighed without tubes, and sediment was removed from the body cavity of specimens of Ctenodiscus crispatus prior to weighing. Samples were collected on cruises JR16006 and JR17007. Funding was provided by ''The Changing Arctic Ocean Seafloor (ChAOS) - how changing sea ice conditions impact biological communities, biogeochemical processes and ecosystems'' project (NE/N015894/1 and NE/P006426/1, 2017-2021), part of the NERC funded Changing Arctic Ocean programme.
Datasets from a deep sediment trap (3200m) mooring deployed in the Southern Ocean, south-west of South Georgia in December 2009 during the marine cruise JR228 and recovered in November 2011 by the marine cruise JR260a.
Datasets from a deep sediment trap (3200m) mooring deployed in the Southern Ocean, south-west of South Georgia in April 2007 during the marine cruise JR167 and recovered in January 2008 by the marine cruise JR177.