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

• Main Authors: Gaird, Robin W, Webster, Daniel L, Schorr, Gregory S, Aschettino, Jessica M, Gorgone, Antoinette M, Mahaffy, Sabre D
• Other Authors: CASCADIA RESEARCH COLLECTIVE OLYMPIA WA
• Format: Text
• Language: English
• Published: 2012
• Subjects: Biology; Ecology; *DOLPHINS(MAMMALS); *HABITATS; *WHALES; HAWAII; IDENTIFICATION; PACIFIC OCEAN; PHOTOGRAPHS; POSITION(LOCATION); RANGE(DISTANCE); SATELLITE TRACKING SYSTEMS; SPATIAL DISTRIBUTION; PHOTO-IDENTIFICATION; HRC(HAWAI I RANGE COMPLEX); PMRF(PACIFIC MISSILE RANGE FACILITY); RESIDENCY PATTERNS; SPATIAL USE; WESTERN HRC; LIMPET(LOW IMPACT MINIMALLY PERCUTANEOUS EXTERNAL-ELECTRONICS TRANSMITTERS); BOTTLENOSE DOLPHINS; KILLER WHALES; PANTROPICAL SPOTTED DOLPHINS; ROUGH-TOOTHED DOLPHINS; SPINNER DOLPHINS; SOCIAL NETWORKS; Lone; Pacific; Marine Mammal Monitoring
• Online Access: http://www.dtic.mil/docs/citations/ADA570925; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA570925

Although considerable information is available on residency patterns and spatial use of odontocetes in the eastern half of the Hawai i Range Complex (HRC), much less is known about odontocetes in the western half of the HRC. In the second year of a three-year effort in the western main Hawaiian Islands we undertook surveys off Kaua i and Ni ihau in July/August 2011, to examine spatial use and residency patterns using satellite tags, to provide visual verification of acoustically-detected odontocetes on the Pacific Missile Range Facility (PMRF), and to obtain individual identification photographs and biopsy samples for assessment of population identity and structure. During 18 days of field effort we covered 1,972 km of trackline and had 65 encounters with five species of odontocetes. Twenty-four of the encounters, of three species, were cued by acoustic detections from the Marine Mammal Monitoring on Navy Ranges (M3R) system, thus providing species verifications for future use of the M3R system on the PMRF range. During the 65 encounters we obtained 22,645 photos for individual and species identification, and collected 48 biopsy samples for genetic analyses. One encounter with a group of four killer whales was only the second encounter with this species in 12 years of directed field surveys in Hawaiian waters. Photos from that encounter were compared to our photo-identification catalog but no matches were found, further suggesting that there is no population of this species resident to the Hawaiian Islands. There were three encounters with a lone pantropical spotted dolphin, each time in association with a group of spinner dolphins. Photos of this individual matched to a spotted dolphin identified off Kaua i in 2004 and in 2005, both times with spinner dolphins, suggesting this individual may be part of a long-term association with spinner dolphins. Four satellite tags were deployed; three on rough-toothed dolphins and one on a bottlenose dolphin. Sponsored in part by NAVFAC/PD.