Spatio-temporal patterns in Antarctic minke whale (Balaenoptera bonaerensis) vocal behaviour in the Weddell Sea

• Main Author: Filun, Diego
• Other Authors: Brey, Thomas, Van Opzeeland, Ilse, Širović, Ana, Hagen, Wilhelm
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universität Bremen 2022
• Subjects: Antarctic; Bioacoustics; marine mammals; Weddell Sea; 570; 570 Life sciences; biology; ddc:570; Austral; Southern Ocean; Weddell; Antarc*; Antarctic Minke whale; Balaenoptera bonaerensis; baleen whale; minke whale; Sea ice; ice covered areas; ice covered waters
• Online Access: https://media.suub.uni-bremen.de/handle/elib/6222; https://doi.org/10.26092/elib/1784; https://nbn-resolving.org/urn:nbn:de:gbv:46-elib62225

Antarctic minke whales (AMW) have a circum-antarctic distribution and are known to occur in both open and ice-covered waters of the Southern Ocean (SO). They are a pagophilic species and are regularly observed in heavily sea-ice covered areas. Because of this, current knowledge about Antarctic minke whales is scarce and limited to austral summer and ice-free regions where the majority of visual survey data have been collected. Hence, very little is known on their winter distribution in high latitude waters and to what extent the wintering individuals that are occasionally observed in Antarctic waters represent single observations or a structurally present behavioral trait of the species. Likewise, AMW population structure is poorly known. As most baleen whale species, AMWs are known to undertake annual migrations between high latitude feeding areas and low latitude breeding areas. However, available data to date suggest that for AMWs, migrations seem more protracted and complex than in other baleen whale species. The recent identification of vocalizations produced by AMWs (“bio-duck call”) now makes it possible to also use passive acoustic technology to study occurrence patterns and behavior. Passive acoustic monitoring (PAM) offers a versatile technology with which long-term archival data can be collected on sound-producing species using autonomous recording units. Acoustic observation has the additional advantages that it can continue data collection independent of light conditions and under poor weather conditions. Furthermore, it can monitor large areas at the same time, since it collects data omnidirectionally, and it can collect data over extended periods (i.e., multi-year time scales) through the use of autonomous devices. In the scope of this doctoral thesis, I analysed passive acoustic data from high and low latitudes collected in the Atlantic Ocean sector of the Southern Ocean (Weddell Sea) and southern Atlantic Ocean, to investigate spatio-temporal patterns in the acoustic presence and vocal behaviour ...