Odontocete Studies on the Pacific Missile Range Facility in July/August 2013: Satellite-Tagging, Photo-Identification, and Passive Acoustic Monitoring.

摘要

A joint project in July and August 2013 on and around the Pacific Missile Range Facility (PMRF) combined passive acoustic monitoring and boat- based field efforts. There were 671 kilometers (36.6 hours hr) of small- vessel survey effort over the course of the 8-day project, with 55.1 percent of time (20.2 hr) spent within the PMRF instrumented hydrophone range boundaries. A total of 33.0 hr of acoustic monitoring coincided with the small-vessel field effort. There were 18 sightings of four species of odontocetes, five of which were directed by acoustic detections from the Marine Mammal Monitoring on Navy Ranges (M3R) system. Bottlenose dolphins (Tursiops truncatus) were encountered on six occasions, spinner dolphins (Stenella longirostris) on three, rough- toothed dolphins (Steno bredanensis) on eight, and false killer whales (Pseudorca crassidens) once. Recordings on the M3R system were made for three of the four species (all but spinner dolphins) to improve species classification for future acoustic monitoring efforts. During the encounters 4, 393 photos were taken for individual identification, two biopsy samples were obtained for genetic studies, and three depth-transmitting satellite tags were deployed on two species (one false killer whale, two rough-toothed dolphins). Data were obtained from the two tagged rough-toothed dolphins for 9.9 and 13.4 days. During this period they remained associated with Ni'ihau, with each found inside PMRF range boundaries on 11 occasions, spending 34 percent and 46 percent of their time on PMRF, respectively. The tagged false killer whale was identified as part of the Northwestern Hawaiian Islands population, known from previous efforts to use the area around Kaua'i. Data were obtained for 21.3 days; during this period the tagged individual was found inside PMRF boundaries on 17 occasions, spending 24 percent of its time on PMRF.