This dataset contains data from a study of pteropod shell dissolution on individuals exposed to CO2-enriched seawater. The data include the amount of dissolution as well as the physical and chemical parameters on which carbonate chemistry parameters were calculated.

Benthic Macrofaunal abundance and biomass data collected during a series of ship-board sampling campaigns in the Barents Sea. As part of the NERC funded Changing Arctic Ocean programme, in July of 2017, 2018 and 2019, the RSS James Clark Ross followed a North-South transect at 30 degrees Longitude. In 2017 six stations were sampled (B3, B13, B14, B15, B16, B17); in 2018 seven stations were sampled (B3, B13, B14, Xs, B15, B16, B17); and in 2019 five stations were sampled (B3, B13, B14, B15, B16). Macrofaunal samples were collected using a USNL corer (surface area 0.1m<sup>2</sup>). On recovery all faunal samples were fixed and preserved with 10% buffered formaldehyde solution. The faunal samples were transported to Plymouth Marine Laboratory where the fauna were extracted, identified to species level where possible using the most up to date literature available, and biomassed (blotted wet weight) to species level. A reference collection has been created containing an example of each taxon to ensure maximum quality control was maintained by the three analysts that conducted the species identification and for subsequent cruise data generated. Funded by the NERC Changing Arctic Ocean Seafloor (ChAOS).

High-resolution X-ray computed tomography images of two deep-sea bamboo corals (Acanella arbuscula, Johnson, 1862; Keratoisis sp., Wright, 1869) collected from Baffin Bay and Davis Strait during a research expedition on board the CCGS Amundsen in July-August 2021. Corals were imaged using Micro-Focused X-Ray Computed Tomography at the Micro-Vis X-ray Imaging Centre (Southampton, UK) to non-destructively investigate their skeletal architecture, calcification strategies and growth patterns. Supported by a National Environmental Research Council Funded (INSPIRE) PhD [grant number NE/S007210/1, 2019-2027, awarded to T.J.W] and the National Research Facility for Lab X-ray CT (NXCT) [EPSRC grant number EP/T02593X/1].

DNA sequencing data from octopus samples collected in the Southern Ocean. A small tissue sample was taken from the mantle of each octopus and placed immediately in 70 - 80 % ethanol for preservation, in preparation for DNA extraction.

Biological tissue samples from octopus species collected from the Southern Ocean, James Clark Ross cruise no. JR147/145. A large collection of tissue samples from deep sea and Antarctic target groups had already been collected in previous cruises. The specific objective of this cruise was to target three species of octopus, Pareledone charcoti (peak abundance 100m depth), Pareledone turqueti (peak abundance 100-200m) and Adelieledone polymorpha (peak abundance 250-350m), for the micro-evolution (i.e. population genetics) component of the project. Most of the octopuses were captured with an otter trawl, due to its relatively large sampling area and the fact that it can be trawled quickly (4 knots) which prevents octopuses from swimming out of it.

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.