Beaked whales are among the most poorly understood marine mammals. They are deep-diving odontocetes, spending most of their time submerged with infrequent, short surface intervals. Due to this behavior, they are difficult to study using visual observation methods alone . However, recent advancements in passive acoustic detection and survey techniques have shown to provide viable methods for stu dying beaked whales (Yack et al. 2013). In the Gulf of Alaska (GOA), there is little known abo ut beaked whale abundance and distribution.

Passive acoustic monitoring was conducted to detect the presence of marine mammal and anthropogenic sounds in the Navy’s Northwest Training Range Complex (NWTRC) from September 14, 2012 until June 30, 2013. High-frequency Acoustic Recording Packages (HARPs) recorded sounds between 10 Hz and 100 kHz at the shelf slope near Quinault Canyon. Data analysis methods consisted of detection of sounds by analyst scans of long-term spectral averages (LTSAs) and spectrograms, and by automated computer algorithms when possible. The data were divided into three frequency bands for analysis of marine mammal vocalizations and anthropogenic sounds.

Passive acoustic monitoring was conducted in the Gulf of Alaska Temporary Maritime Activities Area (GATMAA) from June 2013 to May 2014 to detect marine mammal and anthropogenic sounds. High-frequency Acoustic Recording Packages (HARPs) recorded sounds between 10 Hz and 100 kHz at five locations: a shelf site offshore Kenai Peninsula (200 m depth, site CA), a continental slope site in deep water (850 m depth, site CB), a slope site offshore Kodiak Island (230 m depth, site KO), a deep offshore site at Pratt Seamount (1000 m depth, site PT), and a deep offshore site at Quinn Seamount (930 m depth, site QN).

Beaked whales (family Ziphiidae) consist of at least 21 different species in six genera with relatively little known about many of the species. Research on this family of odontocetes has increased in the last two decades as a result of a mass stranding event of beaked whales in the Bahamas in 2000 in association with a U.S. Navy training event. Results of this research have identified echolocation click characteristics for several species from different areas of the world based upon both tag data and passive acoustic monitoring data

Passive acoustic monitoring was conducted at two sites in the Navy’s Southern California Range Complex during April 2010 – April 2011. These data provide information on the presence of marine mammals and anthropogenic sound sources. High‐frequency acoustic recording packages documented sounds between 10 Hz and 100 kHz with nearly continuous temporal coverage at a site near Santa Barbara Island (site M) and a site south of San Clemente Island (site N). For this reporting period, 8,099 hours of acoustic recordings were obtained from site M and 7,779 hours of recordings from site N. Data analysis methods consisted of analyst scans of long‐term spectral averages and spectrograms. The data were divided into three frequency bands and each band was analyzed for the sounds of marine mammal species or anthropogenic sources. Representative sounds are presented.

Passive acoustic monitoring using High-frequency Acoustic Recording Packages (HARPs) was conducted at two sites in the Navy’s Northwest Training Range Complex; one on the continental shelf near Cape Elizabeth (CE) and the other at the shelf slope near Quinault Canyon (QC). The inshore shelf site was monitored from December 2011 until January 2012, and the offshore shelf slope site was monitored from December 2011 until July 2012. In this report, information on the presence of marine mammals and anthropogenic sounds collected at these sites is presented.

A passive-acoustic glider survey was conducted in the Quinault Range Site (QRS) off the Washington coast between 11 June and 12 July 2012. This glider survey was conducted with funding from the U.S. Navy’s Office of Naval Research (ONR); awards # N00014-10-1-0515 and # N00014-08-1-1082. The survey was part of the development effort of the passive-acoustic Seaglider, which is currently being used for a marine mammal monitoring project funded by U.S. Pacific Fleet through contract N62470-10D-3011, task orders KB23 and KB25, with Naval Facilities Engineering Command (NAVFAC) Pacific. The purpose of this field trial was primarily to test the general functionality of the passive acoustic monitoring (PAM) board and a new onboard acoustic data-storage system (Revision A).

Passive acoustic monitoring was conducted in the Gulf of Alaska Temporary Maritime Activities Area (GATMAA) from April 2014 to May 2015 to detect marine mammal and anthropogenic sounds. High-frequency Acoustic Recording Packages (HARPs) recorded sounds between 10 Hz and 100 kHz at five locations: a shelf site offshore Kenai Peninsula (200 m depth, site CA), a continental slope site in deep water (900 m depth, site CB), a slope site offshore Kodiak Island (200 m depth, site KO), a deep offshore site at Pratt Seamount (1000 m depth, site PT), and a deep offshore site at Quinn Seamount (900 m depth, site QN).

Passive acoustic monitoring was conducted in the Gulf of Alaska Temporary Maritime Activities Area (GATMAA) from May to September 2015 and from April to September 2017 to record the low-frequency ambient soundscape and detect marine mammal and anthropogenic sounds during times of naval exercises in the area. High-frequency Acoustic Recording Packages (HARPs) recorded sounds between 10 Hz and 100 kHz at three locations: a continental slope site in deep water (900 m depth, site CB), a deep water site (hydrophone was placed at 1200 m at a location where depth was approximately 4000 m, site AB), and a deep offshore site at Quinn Seamount (900 m depth, site QN).

The Gulf of Alaska is an important habitat for a diverse array of marine mammals, many of which were severely depleted by historical whaling. To study current cetacean distributions in this region, passive acoustic monitoring was used to detect species-specific call types between 2011 and 2015 at five locations spanning the continental shelf, slope, and offshore seamounts. Spatial and temporal detection patterns were examined for nine species to compare differences in behavior and habitat use.

Here we present analyses of the DASBR deployments from the CCES 2018 project. We provide information on the times and locations of drift deployments and retrievals. Each drift is also illustrated on maps of the study area. We present analyses of cetacean echolocation detections 2 from DASBR recordings including those from beaked whales, sperm whales, and NBHF species. As in the previous 2016 study, beaked whale detections were dominated by Cuvier’s beaked whale. All the beaked whale species detected in 2016 were also detected in this 2018 study, plus the addition of a signal, designated BWC that had been previously detected in the central and western Pacific, but not previously in the eastern Pacific. Sperm whales and NBHF species were detected throughout the study area.

A visual and acoustic line-transect survey of marine mammals was conducted in the central Gulf of Alaska (GoA) during the summer of 2013. The survey area was divided into four sub-strata to reflect four distinct habitats; ‘inshore’, ‘slope’, ‘offshore’ and ‘seamount’. Passive acoustic monitoring was conducted using a towed-hydrophone array system. One of the main objectives of the acoustic survey was to obtain an acoustic-based density estimate for beaked whales. Three species of beaked whales were identified; Cuvier’s (Ziphius cavirostris), Baird’s (Berardius bairdii) and Steijneger’s (Mesoplodon stejnegeri).