This dataset contains atmospheric methane and carbon dioxide concentration data in the Southern Ocean and South Atlantic Ocean, and dissolved methane concentration data from surface and water column seawater samples in the Scotia Sea, Weddell Sea, and South Georgia shelf taken onboard RRS Discovery during DY158 from December 2022 and January 2023. Atmospheric methane and carbon dioxide concentration was measured using a Los Gatos Ultraportable Greenhouse Gas Analyser (UGGA) G2311-f. The concentrations are 2 hour averaged and have been filtered based on wind direction to data corresponding to wind coming from behind the ship to remove sources of pollution from the ship stack. Surface seawater samples were taken either using the uncontaminated seawater system or from the surface sample from a CTD (Conductivity-Depth-Temperature) cast. Water column seawater samples were taken from a CTD with Niskin bottle rosette-casts at various depths spanning from the sea surface to the seafloor. The dissolved methane concentration in each seawater sample is measured using gas chromatography. Funding source: This work was supported by the Natural Environment Research Council and the ARIES Doctoral Training Partnership (grant no. NE/S007334/1). The fieldwork was supported by the Collaborative Antarctic Science Scheme (CASS).

Measurements were collected during the 92 day lab-based experiment carried out on replicate macrofaunal mesocosms of Astarte crenata, Ctenodiscus crispatus, Cistenides hyperborea from the Western Barents Sea and Aequiyoldia eightsi and Laternula elliptica from Rothera Point, Antarctic Peninsula. Macrofauna were collected on cruise JR18006 in the Western Barents Sea and by hand during scuba dives in the cove adjacent to Rothera research station. Experimental measurements include carbonate chemistry indices measured in water samples; carbon dioxide concentration levels; benthic invertebrate response rate, burial rate, sediment particle reworking, bioirrigation, and associated nutrient concentrations; benthic invertebrate body size and individual biomass; sediment organic material content, and sediment particle size. Supported by the INSPIRE Doctoral Training Partnership programme (grant NE/S007210/1) and ''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), Natural Environment Research Council (NERC) in the UK.

Seawater samples between 2010-12-28 and 2020-02-28 were collected year-round and quasi-weekly in Ryder Bay, along the West Antarctic Peninsula, as part of the Rothera Oceanographic Time Series (RaTS). The majority of samples were collected at 15 m depth. At a lower frequency, samples were collected at additional depths, i.e., mostly at 40 m, 5, m, and 2 m. Samples have been analysed for dissolved inorganic carbon (DIC) and total alkalinity (TA) to study the carbonate chemistry of the upper ocean, from which the fugacity of CO2 (fCO2) is derived. This dataset also includes additional variables of the RaTS-array that are ancillary to DIC and TA results, and to fCO2 calculations: seawater temperature, salinity, and nutrients (nitrate, silicate, and phosphate). DIC/TA data between 2010-12-28 and 2014-02-21 have previously been published in NCEI by Bakker et al. (2017), and are included in this dataset. Physical variables and nutrient data have also been published in the UK Polar Data Centre by Clarke et al. (2022). Funding Sources: Funding sources for Rothera Time Series 2014-2020: - The Rothera Time Series has been funded by NERC through a sequence of National Capability awards, most recently PRESCIENT (NE/Y006178/1). - ESD: NE/L002582/1 and European Union''s Horizon 2020 research and innovation programme under grant agreement no. 821001 - DCEB: partly supported by the NERC PICCOLO award (NE/PO21395/1). - EJ: research programme 866.13.006 (partly) financed by the Netherlands Polar Programme at NWO. - MPM: partly funded by BIOPOLE award (NE/W004933/1). Funding sources for Rothera Time Series 2010-2014: - British Antarctic Survey (BAS) Polar Oceans funding from NERC - UK Ocean Acidification Research Programme (NE/H017046/1) funded by NERC, the Department for Energy and Climate Change and the Department for Environment, Food and Rural Affairs - OJL: PhD funding from NERC: NE/L50158X/1 - DCEB: NERC Shelf Sea Biogeochemistry Blue Carbon work package (NE/K00168X/1)

Datasets from a deep sediment trap (3200m) mooring deployed in the Southern Ocean, south-west of South Georgia in November 2014 during the marine cruise JR304 and recovered in November 2015 by the marine cruise JR15002.

A Deep sediment trap (3200m) mooring has been deployed in the Southern Ocean, south-west of South Georgia during multiple marine cruises from April 2007 onwards as part of a long-term monitoring and assessment of the status of the marine ecosystems in the region of South Georgia. Measurements were made for sustained observations of zooplankton densities, carbon export and effects of ocean acidification. Standard datasets include profiles from a Conductivity-Temperature-Depth (CTD) analyser and Acoustic Doppler Current Profiler (ADCP). In addition, data from a deep and shallow sediment trap, current meter, O2 sensor, CO2 sensor and pH sensors were collected. Funding was provided by the Scotia Sea open-ocean observatory (SCOOBIES) project. Data Access is provided via the RELATED DATA SET METADATA links.

A Deep sediment trap (3700m) mooring has been deployed in the Southern Ocean, north-west of South Georgia during multiple marine cruises from November 2006 onwards as part of a long-term monitoring and assessment of the status of the marine ecosystems in the region of South Georgia. Measurements were made for sustained observations of zooplankton densities, carbon export and effects of ocean acidification. Standard datasets include profiles from a Conductivity-Temperature-Depth (CTD) analyser and Acoustic Doppler Current Profiler (ADCP). In addition, data from a deep and shallow sediment trap, current meter, O2 sensor, CO2 sensor and pH sensors were collected. Funding was provided by the Scotia Sea open-ocean observatory (SCOOBIES) project. Data Access is provided via the RELATED DATA SET METADATA links.