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 presents temperature readings collected from the waters around South Georgia in the years 2019, 2021, 2023, and 2024. From 2021 onwards, depth readings are also presented. The data were obtained using temperature loggers affixed to longlines operating in the South Georgia Patagonian toothfish fishery. These in situ measurements were conducted to monitor the water temperatures around South Georgia. The deployment of the temperature loggers was carried out by fishing vessel crew and fisheries observers working on behalf of the Government of South Georgia and the South Sandwich Islands (GSGSSI). The data were collated by the Centre for Environment Fisheries and Aquaculture Science (Cefas). The collection and analysis of this data series was part-funded by the UK Government Blue Belt Programme in partnership with the Government of South Georgia and the South Sandwich Islands. The procurement of some of the temperature loggers was funded by Argos Froyanes Limited.

The quantities of key biologically active elements, carbon, nitrogen, and hydrogen, were measured from batches of eggs from the Antarctic Krill, Euphausia superba. These krill were collected in the "Western Core Box" krill time series region, an area to the north-west of South Georgia, on the RRS James Clark Ross research cruise JR17002 in the summer (January) 2018. Eggs were collected from ship board incubation experiments. Maternal parasite assemblage and load was determined using DNA metabarcoding. Krill with higher loads of apicomplexa and ciliate parasites laid eggs with lower quantities of carbon and nitrogen. These lower quality eggs may have lower survival and recruitment success, suggesting a mechanism by which parasites may influence krill population dynamics. Funding source: This research was supported by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 887760 (ParaKrill).

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 comprises conventional stomachs contents data for the biomass-dominant species of mesopelagic fish, particularly myctophid fish (Family Myctophidae) in the Scotia Sea. The data were collected by depth-discrete RMT25 net trawls deployed between 0-1000 m between the Antarctic Polar Front and the South Orkney Islands. Samples were collected repeatedly at nominal sampling stations during austral autumn 2004, spring 2006, summer 2008 and autumn 2009 for analyses examining the trophodynamics of Southern Ocean mesopelagic fish and their role in the food web. The data are the quantitative measures of diet composition (prey abundance, frequency and mass) observed from microscope analyses of individual fish stomachs per species.

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.

This is a mixed data set held in six excel files, containing processed acoustic backscatter data, mesopelagic fish abundance and swimbladder contents from night time sampled RMT25 nets, plus net catch data for all fauna combined and dominant mesopelagic fish in night time RMT25. Acoustic backscatter data is from 6 latitudinal acoustic transects spanning the Scotia Sea, obtained during cruises JR161, JR177, JR200, JR15002 and JR15004 (two transects). Data were collected using a Simrad EK60 echo sounder at 38 kHz. The EK60 was run continuously between Stanley (Falkland Islands) and Signy (South Orkney Islands). Fish data was collected using RMT25 night time net samples from 5 cruises JR161, JR177, JR200, JR15004 and JR16003. The data set focuses on 11 species of mesopelagic fish Bathylagus species, Cyclothone species, Electrona antarctica, Electrona carlsbergi, Gymnoscopelus braueri, Gymnoscopelus fraseri, Gymnoscopelus nicholsi, Krefftichthys anderssoni, Protomyctophum bolini, Protomyctophum tenisoni and Notolepis species. Abundance and proportion data was obtained for combined fish species, and identified by net tow and latitude. Biomass for all fauna and the 11 fish species was calculated from RMT25 night catch log data. Myctophid gas presence absence was determined from a combination of dissection, Computed Tomography and soft tissue X-ray. Funding was provided by the NERC grants NE/L002434/1 and bas010017. This data is embargoed until August 2019.

Between 1980 and 2009, marine macronutrient concentrations (silicate, Si(OH)4-Si; phosphate, PO4-P; nitrate, NO3-N; ammonium, NH4-N; and nitrite, NO2-N) and concurrent temperature and salinity were measured by British Antarctic Survey researchers as part of an integrated ecosystem investigation. Areas sampled included South Georgia and the wider Scotia Sea, around the Antarctic Peninsula, and in the Bellingshausen Sea. The data were collected from aboard the RRS John Biscoe or the RRS James Clark Ross during all months of the year with the exceptions of May and June. Samples were collected from CTD water bottles (vertical profiles) to maximum depth of 5400 m, and by monitoring continuously the ship's non-toxic seawater supply (intake at 6 - 7 m) while the vessel was transecting. Analyses were performed immediately aboard ship and logged to computer while full data analysis was performed post-cruise using custom written software programmes. The data collection was enabled through Natural Environment Research Council National Capability funding to the British Antarctic Survey. This was organised through a series of BAS programmes including the Offshore Biological Research programme, the DYNAMOE programme and the ECOSYSTEMS programme. Data creation was facilitated through a combination of NERC funding for Antarctic Logistics and Infrastructure (ALI) Science and the NERC Science Multi-Centre Round 2 (NCSM2) programme BIOPOLE (NE/W004933/1).