Acoustic backscatter data were collected on board the RRS Sir David Attenborough during polar science trials 2023 (cruise SD025) on 25/02/2023 in Admiralty Bay, King George Island, Antarctica. Data were collected using a Simrad EK80 echosounder at 18, 38, 70, 120, 200 and 333 kHz. The EK80 was calibrated on 10/03/2023 in the Weddell Sea. This work was supported by NERC core funding to BAS.

Acoustic backscatter data were collected on board the RRS Discovery during cruise DY158 on 05/01/2023 in Stromness Bay, South Georgia. Data were collected using a Simrad EK80 echosounder at 18, 38, 120, 200 and 333 kHz. Funding source: This work was carried out in the frame of WCB-POETS survey cruises, and the methane survey was funded by the Collaborative Antarctic Science Scheme (CASS).