Movements and Spatial Use of Odontocetes in the Western Main Hawaiian Islands: Results From Satellite-tagging and Photo-Identification Off Kaua'i and Ni'ihau in July/August 2011
Technical rept. 1 Oct 2010-30 Sep 2011
CASCADIA RESEARCH COLLECTIVE OLYMPIA WA
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This report summarizes the second year of a three-year effort in the western main Hawaiian Islands to study the residency patterns and spatial use of odontocetes in the Hawaii Range Complex. Surveys were made off Kaua i and Ni ihau over eighteen days in JulyAugust 2011, during which time there were 65 encounters with five species of odontocetes. Twenty-four of those encounters were cued by acoustic detections from the Marine Mammal Monitoring on Navy Ranges M3R system from the Pacific Missile Range Facility, thus providing species verifications of the acoustic system. Additionally, 22645 photographs for individual and species identification, and forty-eight biopsy samples for genetic analyses, were collected. Some highlights of the field work include the first ever satellite tag deployments on free-ranging rough-toothed dolphins, and the first satellite tag deployment in Hawaiian waters of a bottlenose dolphin only the second encounter with killer whales in twelve years of surveys in Hawaiian waters and encounters with a lone pantropical spotted dolphin, always in association with a group of spinner dolphins, as has been similarly documented in 2004 and 2005. The latter two highlights suggest, respectively, that there is no resident Hawaiian killer whale population, and that this particular at least pantropical spotted dolphin has a long-term association with spinner dolphins. The first highlight has provided the first unbiased movement and habitat use data for both rough-toothed and bottlenose dolphins in Hawaiian waters.