Benthic images collected over different terrain features by Autonomous Underwater Vehicle during expedition JC257, 30 km south from the northern border of the UK-1 area of the Clarion-Clipperton Zone, Pacific Ocean, 2024.

A collection of 2061 benthic still images was obtained using a downward-looking camera mounted on the UK Autosub5 Autonomous Underwater Vehicle (AUV), deployed from RRS James Cook during cruise JC257 in the abyssal plain (~4100 m depth) of the UK-1 exploration area of the Clarion-Clipperton Zone, Pacific Ocean, in 2024. During mission AS5M097, the AUV was programmed to replicate 21 parallel 1 km long transect lines in a site located 30 km South from the northern border of the UK-1 exploration area. The Grasshopper2 GS2-GE-50S5C camera mounted on the AUV collected vertically orientated still images at a target altitude of 3 m above the seabed, with one image being captured per second. Terrain features exhibiting different slope were delimited and images within each feature were randomly subsampled. These images were colour corrected to enhance visual fidelity and converted from original 8-bit RAW to JPG images. The final image set was inspected for overlap, which was non-existent. The image set was subsequently annotated using the online platform BIIGLE to derive ecological understanding on the influence of seabed topography on seabed community composition. The data were collected by scientists from the National Oceanography Centre, Southampton, UK as part of the NERC-funded Seabed Mining And Resilience To EXperimental impact (SMARTEX) project (NE/T003537/1).