New insights into prime Southern Ocean forage grounds for thriving Western Australian humpback whales

• Published in: Scientific Reports
• Main Authors: Bestley, S, Andrews-Goff, V, van Wijk, E, Rintoul, SR, Double, MC, How, J
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2019
• Subjects: Southern Ocean; Kerguelen plateau; Antarctic Circumpolar Current; humpback whales; migration ecology; movement modelling; Antarctic; Austral; Kerguelen; Antarc*; Humpback Whale
• Online Access: https://eprints.utas.edu.au/31581/; https://eprints.utas.edu.au/31581/2/135036%20-%20New%20insights%20into%20prime%20Southern%20Ocean%20forage%20grounds.pdf

Humpback whale populations migrate extensively between winter breeding grounds and summerfeeding grounds, however known links to remote Antarctic feeding grounds remain limited in manycases. New satellite tracks detail humpback whale migration pathways from Western Australia intothe Southern Ocean. These highlight a focal feeding area during austral spring and early summer atthe southern Kerguelen plateau, in a western boundary current where a sharp northward turn andretroflection of ocean fronts occurs along the eastern plateau edge. The topographic steering ofoceanographic features here likely supports a predictable, productive and persistent forage ground. Thespatial distribution of whaling catches and Discovery era mark-recaptures confirms the importance ofthis region to Western Australian humpback whales since at least historical times. Movement modellingdiscriminates sex-related behaviours, with females moving faster during both transit and residentperiods, which may be a consequence of size or indicate differential energetic requirements. Relativelyshort and directed migratory pathways overall, together with high-quality, reliable forage resourcesmay provide a partial explanation for the ongoing strong recovery demonstrated by this population.The combination of new oceanographic information and movement data provides enhancedunderstanding of important biological processes, which are relevant within the context of the currentspatial management and conservation efforts in the Southern Ocean.