Marine soundscape variation reveals insights into baleen whales and their environment: a case study in central New Zealand

• Main Authors: Warren, Victoria, McPherson, Craig, Giorli, Giacomo, Goetz, Kimberly, Radford, Craig
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2021
• Subjects: power spectral density; New Zealand; 1 Hz average; Antarc*; Antarctic; baleen whales; Blue whale
• Online Access: https://doi.org/10.5061/dryad.vmcvdncpj

Baleen whales reliably produce stereotyped vocalizations, enabling their spatio-temporal distributions to be inferred from acoustic detections. Soundscape analysis provides an integrated approach whereby vocal species, such as baleen whales, are sampled holistically with other acoustic contributors to their environment. Acoustic elements that occur concurrently in space, time and/or frequency can indicate overlaps between free-ranging species and potential stressors. Such information can inform risk assessment framework models. Here, we demonstrate the utility of soundscape monitoring in central New Zealand, an area of high cetacean diversity where potential threats are poorly understood. Pygmy blue whale calls were abundant in the South Taranaki Bight (STB) throughout recording periods and were also detected near Kaikōura during autumn. Humpback, Antarctic blue and Antarctic minke whales were detected in winter and spring, during migration. Wind, rain, tidal, and wave activity increased ambient sound levels in both deep- and shallow water environments across a broad range of frequencies, including those used by baleen whales, and sound from shipping, seismic surveys and earthquakes overlapped in time, space and frequency with whale calls. The results highlight the feasibility of soundscape analysis to quantify and understand potential stressors to free-ranging species, which is essential for conservation and management decisions. Data matrices contain the 1 Hz Power Spectral Density per 630-second, 16 kHz file. The first column of the Data matrices displays the Frequency value, and all other columns contain data values. The associated file names (containing recording time and date information) are provided in the separate 'Header' files. The width of the Header file is the same as the width of the Data file due to identification of the Frequency column. Funding provided by: OMV New Zealand Ltd Crossref Funder Registry ID: Award Number: Funding provided by: Chevron New Zealand Holdings LLC Crossref Funder ...