Occurrence of killer whales ( Orcinus orca ) and other cetaceans in Terra Nova Bay, Ross Sea, Antarctica

• Published in: Antarctic Science
• Main Authors: Lauriano, Giancarlo, Fortuna, Caterina Maria, Vacchi, Marino
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2010
• Subjects: Geology; Ecology, Evolution, Behavior and Systematics; Oceanography; Antarctic; Ross Sea; Terra Nova Bay; Drygalski; Mario Zucchelli; Mario Zucchelli Station; Edmonson Point; Drygalski Ice Tongue; Campbell Glacier; Campbell Glacier Tongue; Antarc*; Antarctic Science; Antarctica; Balaenoptera bonaerensis; Killer Whale; Orca; Orcinus orca; Killer whale
• Online Access: http://dx.doi.org/10.1017/s0954102010000908; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102010000908

Abstract During January and February 2004, data on presence and distribution of killer whales ( Orcinus orca ) and other cetaceans were collected by helicopter surveys along the coastline of Terra Nova Bay and adjacent localities (western Ross Sea, Antarctica). A total of 37 sightings of killer whale, of both B and C types, were recorded as well as 17 sightings of Antarctic minke whales ( Balaenoptera bonaerensis ), nine of Balaenoptera spp., two of Arnoux’s beaked whale ( Berardius arnuxii ) and four of undetermined species. The type C killer whale was the most abundant, with 23 sightings, whereas we recorded type B only twice. Group size ranged between 1 and 30 animals, with an average of eight individuals. Seventeen killer whales were photo-identified and 13 resightings occurred during the study period. Killer whales showed a differential pattern in partitioning the study area. Their encounter rate was significantly higher ( t -test = 2.6045, P < 0.05) in the northern area extending from Edmonson Point to the Campbell Glacier Tongue (encounter rate, ER = 0.031), compared to the southern area from Mario Zucchelli Station to the Drygalski Ice Tongue (ER = 0.003).