This dataset contains long-term underwater acoustic recordings made under Australian Antarctic Science Projects 4101 and 4102, and the International Whaling Commission’s Southern Ocean Research Partnership (IWC-SORP) Southern Ocean Hydrophone Network (SOHN). Calibrated measurements of sound pressure were made at several sites across several years using custom moored acoustic recorders (MARs) designed and manufactured by the Science Technical Support group of the Australian Antarctic Division. These moored acoustic recorders were designed to operate for year-long, deep-water, Antarctic deployments. Each moored acoustic recorder included a factory calibrated HTI 90-U hydrophone and workshop-calibrated frontend electronics (hydrophone preamplifier, bandpass filter, and analog-digital converter), and used solid state digital storage (SDHC) to reduce power consumption and mechanical self-noise (e.g. from hard-drives with motors and rotating disks). Electronics were placed in a glass instrumentation sphere rated to a depth of 6000 m, and the sphere was attached to a short mooring with nylon straps to decouple recorder and hydrophone from sea-bed. The hydrophone was mounted above the glass sphere with elastic connections to the mooring frame to reduce mechanical self-noise from movement of the hydrophone. The target noise floor of each recorder was below that expected for a quiet ocean at sea state zero. The analog-digital converter, based on an AD7683B chip, provides 100 dB of spurious free dynamic range, but a total signal-to-noise and distortion of 86 dB which yields 14 effective bits of dynamic range at a 1 kHz input frequency. The data for each recording site comprise a folder of 16-bit WAV audio files recorded at a nominal sample rate of 12 kHz. The names of each WAV file correspond to a deployment code followed by the start time (in UTC) of the file as determined by the microprocessor’s real-time clock e.g. 201_2013-12-25_13-00-00.wav would correspond to a wav file with deployment code 201 that starts at 1 pm on December 25th 2013 (UTC). Recording locations were chosen to correspond to sites used during AAS Project 2683. These sites were along the resupply routes for Australia’s Antarctic stations, and typically there was only one opportunity to recover and redeploy MARs each year.

The Davis Aerodrome Project (DAP) collected a range of environmental survey data over several field seasons to support a comprehensive environmental assessment of the proposed aerodrome. This data includes flora, fauna, soils, lake ecosystem, nearshore, marine, air quality and meteorological information which has been collected by a number of different methods, and extends across the current Davis Station, proposed aerodrome and supporting infrastructure footprint (Ridge Site), previous sites considered for the aerodrome (Heidemann Valley, Adams Flat), as well as locations across the Vestfold Hills away from any of the proposed developments. This dataset contains long-term underwater acoustic recordings made for the Australian Antarctic Division’s Davis Aerodrome Project 5097 environmental assessments. Calibrated measurements of sound pressure were made at two sites in the vicinity of Davis Research station (approx. 5km west of the station and one in Long Fjord to the north of station). The attached data was downloaded from the instrument deployed west of Davis Station. Data was recorded over 7 months using a custom moored Autonomous Multichannel Acoustic Recorder (AMAR G4) designed and manufactured by JASCO Applied Science following specifications provided by the Australian Antarctic Division. These moored acoustic recorders were designed to operate for year-long, near shore, Antarctic deployments. The moorings were deployed through the ice during the 2021 winter and one retrieved during the 2021/22 summer when the seaice was clear of the surface. The Autonomous Multichannel Acoustic Recorder is a fully autonomous underwater sound and data recorder. The acoustic recorder included a factory calibrated M36-100 hydrophone, data acquisition electronics and solid state digital storage (SDHC) to reduce power consumption and mechanical self-noise (e.g. from hard-drives with motors and rotating disks). Batteries, SDHC cards and electronics were placed in watertight pressure sealed PVC housing rated to a depth of 250 m. The moorings were secured to the seafloor by weights and suspended up into the water column by a string of floats attached to the top of the structure to separate the recorder and hydrophone from sea-bed. The hydrophone was securely mounted to the base of the AMAR housing. All connections between mooring components where taped with protective coverings to reduce mechanical self-noise from movement of the structure. The target noise floor of each recorder was below that expected for a quiet ocean at sea state zero. The data for each recording site comprise folders of 24-bit WAV audio files recorded on a duty cycle with two different sample rates. The duty cycle recorded for 60 s at a sample-rate of 512 kHz, followed immediately by a 580 s at a sample-rate of 32 kHz, and then 280 s off before repeating. The names of each WAV file correspond to instrument serial number followed by the start time (in UTC) of the file as determined by the AMAR’s real-time clock e.g. AMAR897.20210722T061621Z.wav would correspond to a wav from AMAR serial number 897 that starts at 06:16:21 on 22 July 2021 (UTC).