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).

Year-round measurements of the water column in Ryder Bay, Western Antarctic Peninsula have been collected by the Rothera Marine Assistant and associated researchers, starting in 1997 as part of the Rothera Oceanographic and Biological Time Series (RATS) to assess temporal variability in physical and biogeochemical oceanographic properties. The data were collected using instrumentation deployed from rigid inflatable boats, or through instrumentation deployed through holes cut in the sea ice when the bay is frozen over in winter. Data collected include profiles to about 500m depth with a conductivity-temperature-depth (CTD) system that produces measurements of temperature, salinity, fluorescence and photosynthetically-active radiation (PAR). Individual water samples are collected with a Niskin bottle from a standard 15m depth, with some samples also collected from the surface layer. These individual samples are analysed for size-fractionated chlorophyll, macronutrients (nitrate, nitrite, ammonium, orthophosphate and silicic acid), stable isotopes of oxygen in seawater, and some ancillary parameters. The bottle data have been quality controlled using international reference standards. Profiling and water sample collection occur with quasi-weekly frequency in summer and weekly in winter, but are weather and sea ice dependent. In addition, daily assessments of sea ice concentration and sea ice type are made from nearby Rothera Research Station by visual inspection, to aid interpretation of the ocean data collected. These data constitute one of the longest time series of ocean measurements in Antarctica, with near-unique systematic data collection in winter, within either polar circle. Data collection has been supported since 1997 by the Natural Environment Research Council (NERC) through core funding supplied to the British Antarctic Survey. Since 2017, it has been supported by NERC award "National Capability - Polar Expertise Supporting UK Research" (NE/R016038/1).

Marine macronutrient and particulate material concentrations together with phytoplankton abundance and community composition were measured from samples taken during British Antarctic Survey and UK National Oceanography Centre research cruise JC211 to the Scotia Sea, Southern Ocean, carried out onboard RRS James Cook in February-March 2021. Samples were taken from four sections of the cruise: (i) at the British Antarctic Survey Scotia Sea Open-Ocean Observatory (SCOOBIES) P3 mooring in the Georgia Basin, northwest of South Georgia; (ii) as part of the British Antarctic Survey long-term Polar Ocean Ecosystem Time Series - Western Core Box (POETS-WCB) survey at South Georgia; (iii) in the vicinity of giant iceberg A-68A and associated icebergs; and (iv) as part of the A23 repeat hydrographic section. Samples were collected to maximum depth of approximately 500 m from Niskin water bottles attached to a CTD rosette. Full data analyses were performed post-cruise. Concurrent temperature, salinity, dissolved oxygen, chlorophyll fluorescence and photosynthetically active radiation (PAR) measurements obtained from analysis of water samples and from sensors on the CTD system at the depth and time of each water sample are provided for environmental context. RRS James Cook cruise JC211 was in part supported by the Natural Environment Research Council (NERC) National Capability Science (Antarctic Logistics and Infrastructure; NC-ALI) programme. Further funding for sampling around iceberg A-68 was provided by the Government of South Georgia and the South Sandwich Islands and the UK Government Blue Belt Programme. Data acquisition and analyses were supported by NERC NC-ALI funding to the Ecosystems CONSEC Programme and NERC Grants NE/N018095/1 (ORCHESTRA) and NE/V013254/1 (ENCORE) at the British Antarctic Survey, and by the European Research Council (ERC Starting Grant 678371 ICY-LAB to K Hendry) and NERC Grant NE/K010034/1 (to SF Henley).