This dataset summarises the raw GPS locations obtained by satellite tracking of two southern right whales tagged at South Georgia island on 28th January 2020. One whale, genetically identified as a female, was tracked for 117 days (4,860 tag locations provided) and travelled ~5818km including a short period of time at the ice edge. The second whale, genetically identified as a male, was tracked for 238 days (8,492 tag locations provided) and travelled ~9,885km, including migration through the national waters of Argentina, Uruguay and Brazil. Funding: EU BEST 2.0 Medium Grant 1594, DARWIN PLUS award DPLUS057 and funding from the South Georgia Heritage Trust and Friends of South Georgia Island.

Acoustic backscatter data were collected on board the RRS James Clark Ross during cruise JR19001 on 10/12/2019 in Stromness Harbour and South Georgia. Data were collected using a Simrad EK60 echosounder at 38, 70, 120 and 200 kHz. The EK60 was calibrated on 09/12/2019 in Stromness Harbour, South Georgia. More information about the calibration can be found in the Cruise Report for JR19001. This work was carried in the frame of the Polar Ocean Ecosystem TimeSeries - Western Core Box (POETS-WCB) project.

At-sea surveys of seabirds around South Georgia were undertaken during the austral winter (May to September) in 2010 and 2011. Surveys were conducted in set transects which covered areas primarily targeted by the krill industry, and as well as areas not normally fished. Surveys consisted of simultaneous recordings of seabirds and marine mammals on the surface of the water within a continuous 300m wide strip transect on one side of the vessel, and ''snapshots'' at 300m intervals. Species, positional, environmental and trip data were recorded for each survey. The aim of the project was to investigate the potential interactions between higher predators and the South Georgia krill fishery. These surveys were carried out as part of a wider Overseas Territories Environment Programme (OTEP; SGS701) funded project ''Identifying important and vulnerable marine areas for conservation at South Georgia.'' Phil Trathan (BAS) applied for this grant.

During several austral summers covering a 13 year period, we collected a random sample of body feathers from chicks of 11 sympatric species of Procellariiform (wandering albatross Diomedea exulans -79 individuals in total-, black-browed albatross Thalassarche melanophris - 51-, grey-headed albatross T. chrysostoma - 58 -, light-mantled sooty albatross Phoebetria palpebrata - 34 -, northern giant petrel Macronectes halli - 59 -, southern giant petrel M. giganteus - 60 -, white-chinned petrel Procellaria aequinoctialis - 39 -, blue petrel Halobaena caerulea - 19 - , Antarctic prion Pachyptila desolata - 19 -, South Georgian diving petrel Pelecanoides georgicus - 2 - and common diving petrel P. urinatrix - 6 -) to analyse Delta15N and Delta13C.

Microscopy data on the percentages of liverwort stem length colonised by (i) stained hyphal coils, (ii) stained septate hyphae and (iii) dark septate hyphae, and (iv) percentages of rhizoids colonised by hyphae, in 16 leafy liverwort species sampled from sub-Antarctic South Georgia. Specimens were collected in 2011 and 2016 from 12 sites on the Thatcher Peninsula, South Georgia. The specimens have been deposited in the British Antarctic Survey herbarium. This project was funded by NERC under the British Antarctic Survey Long Term Monitoring programme.

The weights of fledging Gentoo penguin chicks at Maiviken have been monitored since 2010. The colony at Maiviken, can have over 1000 breeding pairs. Each year, just before their departure from the colony, a sample of 50 fledgling birds are weighed as part of a long-term monitoring programme. These data are submitted to the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) as part of their Ecosystem Monitoring Programme (CEMP). This work was funded by Natural Environment Research Council (UK) core funding to the British Antarctic Survey.

The data include size, sex, location and morphological measurements and of Muraenolepis specimens included in Fitzcharles et al. (2021). The morphometric data were primarily collected from fish captured during South Georgia Groundfish Surveys in 2003, 2004 and 2005, with additional data obtained from type specimens and extracted from published descriptions of Muraenolepididae. For genetic studies, tissue samples from the South Georgia specimens were supplemented by additional tissue samples from Muraenolepis in other parts of the Southern Ocean. Source, location and depth of capture are included for all specimens that were sequenced, together with sequence Accession Numbers (to the DNA Database of Japan) for Cox 1 and 16S rRNA sequences. The work was primarily funded by the Government of South Georgia & the South Sandwich Islands and was a component part of Elaine Fitzcharles'' PhD (University of St Andrews).

This dataset contains the mean position of the Southern Antarctic Circumpolar Current front (SACCF) in the Scotia Sea, southwest Atlantic sector of the Southern Ocean. The location of the front was determined from analysis of the geopotential anomaly field calculated from quality-controlled potential temperature and salinity data from the World Ocean Database 1998 (Levitus et al., 1998) supplemented by an additional hydrographic profile obtained from the Scripps Institute of Oceanography, as detailed by Thorpe (2001) and Thorpe et al. (2002). The geopotential anomaly data were gridded at a horizontal resolution of one quarter degree and spanned the period 1911-1990. The front position was generated as part of a studentship awarded to SE Thorpe, funded by the Natural Environment Research Council with CASE support from the British Antarctic Survey. The studentship was supervised by KJ Heywood, MA Brandon and DP Stevens.

This dataset contains processed acoustic backscatter data that reflect integrated density estimates for Antarctic krill (Euphausia superba). The acoustic backscatter data are from the Western Core Box (WCB), comprising 8 acoustic transects that span the shelf-break at South Georgia. The data were obtained from a time series of 22 cruises carried out between 1996/97 and 2019/20. Data were collected using either a Simrad EK500 or EK60 echo sounder by biological oceanographers working at the British Antarctic Survey under the Ecosystems scientific research programme and predecessor Discovery 2010 and Dynamo research programmes. Funding was provided by the NERC/BAS Antarctic, Logistic, Infrastructure (ALI) Science and predecessor Long Term Monitoring Science research programmes.

Platform Transmitting Terminal (PTT) tags were used to track Gentoo penguins from Maiviken and Ocean Harbour, South Georgia, from June to September 2018. PTT tags were attached to the lower back feathers with tape and glue. PTT tags use the ARGOS satellite system to collect geospatial data. Tags were deployed to provide information on the protection afforded to Gentoo penguins by the 12NM no take zone (part of the South Georgia and South Sandwich Island MPA that is closed to fishing), and the krill fishing grounds.