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: Dataset
• Language: English
• Published: Dryad 2020
• Subjects: power spectral density; New Zealand; 1 Hz average; Antarctic; The Narrows; Antarc*; baleen whales; Blue whale
• Online Access: https://dx.doi.org/10.5061/dryad.vmcvdncpj; https://datadryad.org/stash/dataset/doi: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 ... : Four Autonomous Multi-channel Acoustic Recorders (AMARs, JASCO Applied Sciences) were deployed from early June to mid-December 2016 around central New Zealand: in the South Taranaki Bight; in the narrows of Cook Strait; north-east of Kaikōura; and off the east coast of Wairarapa (henceforth referred to as STB, Cook Strait, Kaikōura and Wairarapa, respectively) (Figure 1, Table 1). Three AMARs were redeployed between late-February and early September 2017: two in the same relative Kaikōura and Wairarapa locations and one in STB, 25.2 km southeast of the first STB deployment location (Figure 1, Table 1). A recorder was not redeployed in Cook Strait in 2017. The AMARs at Cook Strait and STB were bottom-mounted on metal baseplates, with the hydrophone 75 cm off the seafloor, in water depths less than 300 m. At Kaikōura and Wairarapa, ultra-deep AMARs were deployed in water depths exceeding 1000 m and were moored on vertical line moorings, approximately 10 m above the seabed. All AMARs were retrieved via the use ...