Past and present distribution, densities and movements of blue whales Balaenoptera musculus in the Southern Hemisphere and northern Indian Ocean

• Published in: Mammal Review
• Main Authors: Branch, T.A., Stafford, K.M., Palacios, D.M., Allison, C., Bannister, J.L., Burton, C.L.K., Cabrera, E., Carlson, C.A., Galletti Vernazzani, B., Gill, P.C., Hucke-Gaete, R., Jenner, K.C.S., Jenner, M.N.M., Matsuoka, K., Mikhalev, Y.A., Miyashita, T., Morrice, M.G., Nishiwaki, S., Sturrock, V.J., Tormosov, D., Anderson, R.C., Baker, A.N., Best, P.B., Borsa, Philippe, Brownell, Jr, R.L., Childerhouse, S., Findlay, K.P., Gerrodette, T., Ilangakoon, A.D., Joergensen, M., Kahn, B., Ljungblad, D.K., Maughan, B., Mc Cauley, R.D., Mc Kay, S., Norris, T.F., Rankin, S., Samaran, Flore, Thiele, D., van Waerebeek, K., Warneke, R.M.
• Other Authors: School of Aquatic and Fishery Sciences, University of Washington Seattle, Marine Research Assessment and Management Group, University of Cape Town, Applied Physics Laboratory Seattle (APL-UW), Joint Institute for Marine and Atmospheric Research, University of Hawaii, Environmental Research Division Pacific Grove, Southwest Fisheries Science Center (SWFSC), NOAA National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA)-NOAA National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA), International Whaling Commission, The Red House, The Western Australian Museum, Western Australian Museum (WAM), Burton, Inconnu, Centro de Conservacion Cetacea (C.C.C.), Centro de Conservacion Cetacea, College of the Atlantic, Blue Whale Study, Australocetus Research, Instituto de Ecología y Evolución, Universidad Austral de Chile, Centre for Whale Research (W.A. Inc.), Centre for Whale Research, The Institute of Cetacean Research, South-Ukrainian Pedagogical University, Cetacean Resources Management Section, National Research Institute of Far Seas Fisheries, Whale Ecology Group, Deakin University Burwood, V.J. Sturrock, Ulitsa Karla Marksa, R.C. Andereson, A.N. Baker, MRI Whale Unit, South African Museum, Institut de Recherche pour le Développement (IRD Nouvelle-Calédonie ), Department of Conservation, Marine Conservation Unit, Oceanography Department, A.D. Ilangakoon, M. Joergensen, APEX Environmental, Ljungblad Associates, B. Maughan, CMST Curtin University, Bio-Waves, Inc.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: Antarctic blue whales; Balaenoptera musculus brevicauda; Balaenoptera musculus indica; Balaenoptera musculus intermedia; distribution; pygmy blue whales; true blue whales; whaling; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.ES]Environmental Sciences/Environmental and Society; [SDE.MCG]Environmental Sciences/Global Changes; Antarctic; The Antarctic; Pacific; Indian; New Zealand; Antarc*; Antarctica; Balaenoptera musculus; Blue whale
• Online Access: https://hal.science/hal-00276539; https://doi.org/10.1111/j.1365-2907.2007.00106.x

International audience 1. Blue whale locations in the Southern Hemisphere and northern Indian Ocean were obtained from catches (303 239), sightings (4383 records of 8058 whales), strandings (103), Discovery marks (2191) and recoveries (95), and acoustic recordings. 2. Sighting surveys included 7 480 450 km of effort plus 14 676 days with unmeasured effort. Groups usually consisted of solitary whales (65.2%) or pairs (24.6%); larger feeding aggregations of unassociated individuals were only rarely observed. Sighting rates (groups per 1000 km from many platform types) varied by four orders of magnitude and were lowest in the waters of Brazil, South Africa, the eastern tropical Pacific, Antarctica and South Georgia; higher in the Subantarctic and Peru; and highest around Indonesia, Sri Lanka, Chile, southern Australia and south of Madagascar. 3. Blue whales avoid the oligotrophic central gyres of the Indian, Pacific and Atlantic Oceans, but are more common where phytoplankton densities are high, and where there are dynamic oceanographic processes like upwelling and frontal meandering. 4. Compared with historical catches, the Antarctic (‘true') subspecies is exceedingly rare and usually concentrated closer to the summer pack ice. In summer they are found throughout the Antarctic; in winter they migrate to southern Africa (although recent sightings there are rare) and to other northerly locations (based on acoustics), although some overwinter in the Antarctic. 5. Pygmy blue whales are found around the Indian Ocean and from southern Australia to New Zealand. At least four groupings are evident: northern Indian Ocean, from Madagascar to the Subantarctic, Indonesia to western and southern Australia, and from New Zealand northwards to the equator. Sighting rates are typically much higher than for Antarctic blue whales. 6. South-east Pacific blue whales have a discrete distribution and high sighting rates compared with the Antarctic. Further work is needed to clarify their subspecific status given their distinctive ...