RV Investigator Voyage IN2021_V01 (TEMPO) Sonobuoy Recordings

Updated: 2026-07-13

This dataset contains acoustic recordings and Antarctic krill 3D coordinates collected during the Marine National Facility (MNF) RV Investigator research voyage IN2021_V01, titled “Quantifying krill abundance for krill monitoring and management off the Australian Antarctic Territory.” The voyage occurred from Hobart (TAS) to Hobart between 29 January and 24 March 2021 (AEST) as part of the 2021 TEMPO (Trends in Euphausiids off Mawson, Predators, and Oceanography) survey. Underwater acoustic data were collected using Directional Frequency Analysis and Recording (DIFAR) sonobuoys deployed primarily at 30 nmi intervals throughout the voyage to record ocean noise and marine mammal vocalizations. A total of 251 sonobuoys were deployed, yielding approximately 460 hours of recordings. Sonobuoy models included AN/SSQ-53F (SonobuoyTechSystems, USA, 2011), Q53F (Ultra Electronics Australia, 2011), and SDSQ955 HIDAR (Ultra Electronics UK, re-lifed 2018). Recordings contribute to Predator Observation studies, providing complementary data on marine mammal presence and distribution beyond visual observations. Blue whales and sperm whales are particularly well-detected acoustically, with additional detections likely for fin whales, humpback whales, Antarctic minke whales, southern right whales, sei whales, killer whales, and vocalizations from leopard seals, crabeater seals, Ross seals, and Weddell seals.