Mesozooplankton were collected with a motion-compensated Bongo net (61 cm mouth diameter, 100 and 200 micrometre meshes) and a mini- Bongo net (18 cm mouth diameter, 50 micrometre mesh nets). Both nets fished to a maximum depth of 400 m but sometimes shallower. Specimens were categorised to the lowest possible taxonomic level, which in some cases encompassed developmental stages but in other cases was limited to higher order taxa. Each taxa was enumerated to determine abundance in units of individuals m-2. The dataset allows examination of the distribution and abundance of these species within the Atlantic sector of the Southern Ocean over a number of years and covering much of the productive season from spring to autumn. The data for the North Atlantic and Arctic covers one season only (summer) and is limited to providing a spatial perspective on the distribution and abundance of mesozooplankton.

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).