New paper on spatial variabilities in humpback whale acoustic presence in the Southern Ocean
We are pleased to announce our new paper in Royal Society Open Science on humpback whales in the Southern Ocean: *Large-scale spatial variabilities in the humpback whale acoustic presence in the Atlantic sector of the Southern Ocean* Elena Schall, Karolin Thomisch, Olaf Boebel, Gabriele Gerlach, Stefanie Spiesecke and Ilse Van Opzeeland Southern Hemisphere humpback whales (/Megaptera novaeangliae/) inhabit a wide variety of ecosystems including both low- and high-latitude areas. Understanding the habitat selection of humpback whale populations is key for humpback whale stock management and general ecosystem management. In the Atlantic sector of the Southern Ocean (/ASSO/), the investigation of baleen whale distribution by sighting surveys is temporally restricted to the austral summer. The implementation of autonomous passive acoustic monitoring, in turn, allows the study of vocal baleen whales year-round. This study describes the results of analysing passive acoustic data spanning 12 recording positions throughout the/ASSO/applying a combination of automatic and manual analysis methods to register humpback whale acoustic activity. Humpback whales were present at nine recording positions with higher acoustic activities towards lower latitudes and the eastern and western edges of the/ASSO/. During all months, except December (the month with the fewest recordings), humpback whale acoustic activity was registered in the/ASSO/. The acoustic presence of humpback whales at various locations in the/ASSO/confirms previous observations that part of the population remains in high-latitude waters beyond austral summer, presumably to feed. The spatial and temporal extent of humpback whale presence in the/ASSO/suggests that this area may be used by multiple humpback whale breeding populations as a feeding ground. The paper is available with open access under the following link: https://royalsocietypublishing.org/doi/10.1098/rsos.201347 Best regards, Elena Schall -- Elena Schall PhD Student Ocean Acoustics Lab Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research Klußmannstr. 3d 27570 Bremerhaven email: elena.schall@awi.de Phone: +49(471)4831-2157
We are pleased to announce our new paper in Scientific Reports on humpback whale song in the Southern Ocean: *Humpback whale song recordings suggest common feeding ground occupation by multiple populations* Elena Schall, Karolin Thomisch, Olaf Boebel, Gabriele Gerlach, Sari Mangia Woods, Irene Roca and Ilse Van Opzeeland Humpback whale males are known to sing on their low-latitude breeding grounds, but it is well established that songs are also commonly produced ‘off-season’ on the feeding grounds or during migration. This opens exciting opportunities to investigate migratory aggregations, study humpback whale behavioral plasticity and potentially even assign individual singers to specific breeding grounds. In this study, we analyzed passive acoustic data from 13 recording positions and multiple years (2011– 2018) within the Atlantic sector of the Southern Ocean (ASSO). Humpback whale song was detected at nine recording positions in five years. Most songs were recorded in May, austral fall, coinciding with the rapid increase in sea ice concentration at most recording positions. The spatio-temporal pattern in humpback whale singing activity on Southern Ocean feeding grounds is most likely shaped by local prey availability and humpback whale migratory strategies. Furthermore, the comparative analyses of song structures clearly show a differentiation of two song groups, of which one was solely recorded at the western edge of the ASSO and the other song group was recorded throughout the ASSO. This new finding suggests a common feeding ground occupation by multiple humpback whale populations in the ASSO, allowing for cultural and potentially even genetic exchange among populations. The paper is available with open access under the following link: https://rdcu.be/cyd88 <https://rdcu.be/cyd88> Best regards, Elena Schall -- Dr. Elena Schall Postdoc Ocean Acoustics Lab Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research Klußmannstr. 3d 27570 Bremerhaven email: elena.schall@awi.de Phone: +49(471)4831-2157
*How do singing whales tell us where they come from?* We are pleased to announce our new paper in Scientific Reports which answers this question ;): *Song recordings suggest feeding ground sharing in Southern Hemisphere humpback whales* Elena Schall, Divna Djokic, Erin C. Ross-Marsh, Javier Oña, Judith Denkinger, Julio Ernesto Baumgarten, Linilson Rodrigues Padovese, Marcos R. Rossi-Santos, Maria Isabel Carvalho Goncalves, Renata Sousa-Lima, Rodrigo Hucke-Gaete, Simon Elwen, Susannah Buchan, Tess Gridley, lse Van Opzeeland The Atlantic sector of the Southern Ocean (ASSO) has one of the highest densities of Antarctic krill (Euphausia superba) compared to other polar and subpolar regions, which attracts migratory baleen whale species to aggregate in this area for feeding. Humpback whales (Megaptera novaeangliae) also sing extensively while on the Southern Ocean feeding grounds which allows for the exploration of song similarity between feeding grounds and breeding populations which helps to understand population mixing. The results of comparative song analyses between the ASSO and the Ecuadorian and Brazilian breeding populations and recordings from the Chilean, South African and Namibian migration routes/mid‑latitude feeding grounds revealed that individuals from at least three humpback whale breeding populations most likely migrate to shared feeding grounds in the ASSO. Humpback whales from different populations potentially mix at different times (i.e., years) at feeding hotspots in variable locations. The ASSO seems to provide sufficient prey resources and seems to present an important area for both cultural and maybe even genetic exchange between populations supporting the maintenance of large gene pools. Assuming that multi‑population feeding hotspots are also suitable habitat for krill and other krill‑dependent predators, these areas in the ASSO should be carefully managed integrating population, ecosystem and fisheries management. The paper is available with open access under the following link: https://rdcu.be/cTN8U Best regards, Elena Schall -- Dr. Elena Schall PostDoc Ocean Acoustics Lab Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research Klußmannstr. 3d 27570 Bremerhaven email:elena.schall@awi.de Phone: +49(471)4831-2157
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Elena Schall