The dataset contains body length and maturity stage measurements of Antarctic krill caught from multiple RMT8 hauls conducted as part of science cruise JR15004 to the South Orkneys in January and February 2016. The measurement followed standard protocols as detailed in Morris et al 1988 and Makarov and Denys 1980. All measurements were made on a random subset of approximately 100-200 individuals per haul. The datasets include measurements made from a total of 11 hauls. The measurements were all made by a single analyst. The work was carried out as part of NERC Antarctic Logistics and Infrastructure Science funding for Southern Ocean Ecosystems.

Here, for the first time in the Southern Ocean, this dataset contains the seasonal occurrence of the zooplankton assemblage in the Northeast Scotia Sea using a sediment trap deployed throughout 2018 (P3 observation site, 52.80 degrees S, 40.14 degrees W). Southern Ocean zooplankton provide globally significant ecosystem services through their role in carbon sequestration, nutrient cycling and food webs. The remote and extreme nature of the Southern Ocean creates significant logistical difficulties for studying zooplankton all year round and there is a significant paucity in winter data. Sediment traps are able to sample throughout the year, providing much needed insight into the seasonality of zooplankton in the Southern Ocean. The dataset is accompanied by temperature data at depth 200 m from the CTD instrument mounted on the P3 observation site mooring. Clara Manno was supported by UK Research and Innovation Future Leaders Fellowships project CUPIDO (MR/T020962/1). Work was carried out as part of the Ecosystems programme at the British Antarctic Survey and the Scotia Sea Open Ocean Laboratories (SCOOBIES) sustained observation programme at the British Antarctic Survey in the frame of a Western Core Box-POETS survey cruise (https://www.bas.ac.uk/project/scoobies/).

Genetic profiling data relating to studies on Antarctic krill, Euphausia superba, that document the sequence of expression of genes over the moult cycle and the spatial-temporal expression of clock genes. This work was carried out to examine rhythmic behaviour patterns in this species - namely diel vertical migration and the moult cycle - and the functioning of the genes that underlie these behaviours. Circadian entrainment experiments were carried out twice during the Discovery 2010 summer cruise (cruise no JR177) using krill caught in nets at latitudes of 60S and 52S. Krill samples from each net were processed and preserved for subequent analysis using molecular biology technique to isolate canonical clock genes.