Odontocetes of the Southern Ocean Sanctuary

Twenty-eight odontocete species were identified as occupying sub-Antarctic and Antarctic habitat covered by the 1994 IWC-established Southern Ocean Sanctuary. Toothed whales evidently play an important part in polar ecosystem. Twenty-two are autochthonous showing a regular, apparently year-round, presence Sanctuary: Physeter macrocephalus, Kogia breviceps, Orcinus orca, Globicephala melas edwardii, Pseudorca crassidens, Lagenorhynchus cruciger, obscurus, Lissodelphis peronii, Cephalorhynchus commersonii, hectori, Tursiops truncatus, Delphinus delphis, Phocoena dioptrica, Hyperoodon planifrons, Berardius arnuxii, Ziphius cavirostris, Tasmacetus shepherdi, Mesoplodon layardii, traversii, grayi, bowdoini hectori. Six considered vagrants into sima, Grampus griseus, Steno bredanensis, peruvianus, densirostris mirus. However, vagrant status of these three mesoplodonts is only provisionally assigned, considering that improved knowledge diagnostic features beaked should, recent years, continue to facilitate at-sea identification. Two having ‘contiguous’ range (records less than 2° north Sanctuary boundaries): ginkgodens (at 39°S) mirus 38°24’S). The habitual southern at least four odontocetes extends significantly farther poleward expected. G. edwardii regularly encountered south Polar Front, much like M. grayi which known reach Ross Sea ice edge (ca. 67°S). Z. cavirostris L. obscurus cross Front occasionally. distribution peruvianus traversii their relation SST unclear. Their southernmost records, 42°31’S 44°17’S respectively, may either be extralimital or, more likely, reflect ordinary austral range. Temporally non-aligned patterns planifrons South African waters suggest stock segregation.