Faecal pellets and eggs of Antarctic silverfish have been collected over the seasons using a sediment trap deployed on 1998 in Terra Nova Bay, Ross Sea, Antarctica in the frame of the National Italian Antarctic Research project (PNRA). Antarctic silverfish (ASF) accounts for over 90% of the local fish communities in the Southern Ocean costal area. Samples have been investigated in order to quantify the contribution of fish faecal pellets and eggs to the export of carbon. Funding: CLIMA project (Climatic Long-term Interactions for the Mass Balance in Antarctica) of the Italian National Program for Research in Antarctica.

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).

These data were generated in a comparative study of protein metabolism (protein synthesis, protein growth and protein degradation) in the Antarctic plunderfish, Harpagifer antarcticus and the Northern European blenny, Lipophrys pholis. The study carried out an examination of protein metabolism in these species at a range over overlapping temperatures covering the environmental range of the species. Protein synthesis was measured using the flooding dose methodology in animals held at the British Antarctic Survey in Cambridge, UK. The experimental work was carried out by Andrew Bowgen and Keiron Fraser. The aim of the study was to examine the effect of ambient habitat temperature on protein metabolism in two ecologically similar, but phylogenetically distant fish species, including one that only inhabited polar latitudes. Andrew Bowgen was funded by a NERC PhD studentship and the study was completed as part of the British Antarctic Survey, Biodiversity, Function, Limits and Adaptations from Molecules to Ecosystems (BIOFLAME) project, part of the NERC funded Biological Responses to Extreme Antarctic Conditions and Hyperextremes (BIOREACH) programme.

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. *******PLEASE BE ADVISED TO USE PROCESSED DATA******* The JR161 EK60 processed data is now available at https://doi.org/10.5285/c831d5e4-8d03-4aea-a6c6-6db101f36d8d.

Mesopelagic fish were sampled in the Scotia Sea using a 25 m2 opening and closing rectangular midwater trawl during five research cruises on RRS John Biscoe and RRS James Clark Ross. Nets sampled discrete layers, from the surface to 1000 m during austral spring, summer and autumn. The data include 17726 individual fish records from 66 taxa, the most abundant of which were myctophids of the genera Electrona, Gymnoscopelus, Krefftichthys and Protomyctophum and bathylagids (Bathylagus sp.). Length (standard length, total length or pre-anal fin length) was measured for the majority of specimens (16837), with sex and weight data also collected for many. The work was conducted as part of the BAS Ecosystems Programmes funded by the UK Natural Environment Research Council.

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.

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.

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). *******PLEASE BE ADVISED TO USE PROCESSED DATA******* The JR200 EK60 processed data is now available at https://doi.org/10.5285/7b86ed5f-0520-4dec-9d1e-f76be05b98c9.

This dataset compiles fish length and weight measurements from the RMT-25 net hauls carried out on Discovery 2010 cruises (JR161, JR177, JR200) in the Scotia Sea, Southern Ocean in spring 2006, summer 2008, and autumn 2009. The dataset comprises of the station net hauls only. Research cruises were led by British Antarctic Survey aboard the RRS James Clark Ross. Net hauls were conducted along a transect from the Antarctic Polar Front to the sea ice zone in the Scotia Sea. Hauls included in this dataset are depth stratified (1000-700 m, 700-400 m, 400-200 m, 200 m to surface). Individual fish lengths, and weights were measured on board. Where weights were not measured, length-weight regressions have been used to estimate fish weight. This data set accompanies the paper by Belcher et al. in Marine Ecology Progress Series, titled, Respiration rates and active carbon flux of mesopelagic fishes (Family Myctophidae) in the Scotia Sea, Southern Ocean.

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). *******PLEASE BE ADVISED TO USE PROCESSED DATA******* The JR179 EK60 processed data is now available at https://doi.org/10.5285/ecc51062-1338-445e-bd3c-2e63487d1953.