During HDR Inc.’s 2022/23 field season, baleen whale sightings included humpback whales, North Atlantic right whales (Eubalaena glacialis), and fin whales (Balaenoptera physalus). This report will focus on results from the humpback whale sightings only

The objective of this project under the U.S. Navy’s Marine Species Monitoring Program is to establish baseline information on occurrence and behavior of humpback whales near Naval Station Norfolk and within the Virginia Capes Operational Area (VACAPES OPAREA) by addressing the following questions: • What age classes (juveniles, sub-adults, adults) are utilizing the waters within and adjacent to the mouth of the Chesapeake Bay? • Do humpback whales exhibit site fidelity over periods of days to years? • Do humpback whales congregate in specific high-traffic and/or high-use U.S. Navy training areas? • Do humpback whales spend significant time within or move through areas of U.S. Navy live-fire and mine neutralization exercise (MINEX) training (Year 2 and Year 3)?

A total of 23 nearshore and mid-shelf vessel surveys were completed during the 2023/24 field season. In total, 43 baleen whale sightings, including 33 sightings of humpback whales (Megaptera novaeangliae) composed of 43 individuals, 6 sightings of North Atlantic right whales (Eubalaena glacialis) composed of 9 individuals (1 deceased), 3 sightings of minke whales (Balaenoptera acutorostrata) composed of 3 individuals, and 1 sighting of a fin whale (Balaenoptera physalus) composed of 1 individual occurred during the 2023/24 field season.

During HDR Inc.’s 2023/24 field season, baleen whale sightings included humpback whales, NARWs, fin whales, minke whales (Balaenoptera acutorostrata), and sei whales (Balaenoptera borealis). This report will focus on the photo-ID results from all baleen whale sightings, photogrammetry results from the drone, and status of the MAHWC and Happywhale matching. See Aschettino et al. (2025) and Engelhaupt et al. (2025) for further information and details from the vessel survey and tagging efforts, and Ozog and Engelhaupt (2025) for details from the supporting aerial surveys.

The objective of this multi-year project under the U.S. Navy’s Marine Species Monitoring Program has been to establish baseline information on occurrence and behavior of humpback whales near Naval Station Norfolk and within the Virginia Capes (VACAPES) Operating Area

The objective of this multi-year project under the U.S. Navy’s Marine Species Monitoring Program has been to establish baseline information on occurrence and behavior of humpback whales near Naval Station Norfolk and within the Virginia Capes (VACAPES) Operating Area (OPAREA)

This work builds upon and complements longer-term studies of movements and site fidelity of both Cuvier’s beaked whales (Ziphius cavirostris) and short-finned pilot whales (Globicephala macrorhynchus) off the North Carolina coast using photo-identiThe objective of this project under the U.S. Navy’s Marine Species Monitoring Program is to establish baseline occurrence and behavior data for humpback whales in the Hampton Roads mid-Atlantic region by addressing the following questions: • What age classes (juveniles, sub-adults, adults) are utilizing the waters within and adjacent to the mouth of the Chesapeake Bay? Do humpback whales exhibit site-fidelity over periods of days to years? Do humpback whales congregate in specific high-traffic and/or high-use U.S. Navy training areas? Do humpback whales spend significant time within or move through areas of U.S. Navy live-fire and MINEX training (Year 2)? What are the relative sound levels humpback whaication (photo-ID)

The objective of this multi-year project under the U.S. Navy’s Marine Species Monitoring Program has been to establish baseline information on occurrence and behavior of humpback whales near Naval Station Norfolk and within the Virginia Capes (VACAPES) Operating Area by addressing the following questions: What age classes (juveniles, sub-adults, adults) are utilizing the waters within and adjacent to the mouth of the Chesapeake Bay? Do humpback whales exhibit site fidelity over periods of days to years? Do humpback whales congregate in specific high-traffic and/or high-use U.S. Navy training areas? Do humpback whales spend significant time within or move through areas of U.S. Navy live-fire and mine neutralization exercise (MINEX) training?

The objective of this multi-year project under the U.S. Navy’s Marine Species Monitoring Program has been to establish baseline information on occurrence and behavior of humpback whales near Naval Station Norfolk and within the Virginia Capes (VACAPES) Operating Area by addressing the following questions: What age classes (juveniles, sub-adults, adults) are utilizing the waters within and adjacent to the mouth of the Chesapeake Bay? Do humpback whales exhibit site fidelity over periods of days to years? Do humpback whales congregate in specific high-traffic and/or high-use U.S. Navy training areas? Do humpback whales spend significant time within or move through areas of U.S. Navy live-fire and mine neutralization exercise (MINEX) training?

The objective of this multi-year project under the U.S. Navy’s Marine Species Monitoring Program has been to establish baseline information on occurrence and behavior of humpback whales near Naval Station Norfolk and within the Virginia Capes (VACAPES) Operating Area by addressing the following questions: What age classes (juveniles, sub-adults, adults) are utilizing the waters within and adjacent to the mouth of the Chesapeake Bay? Do humpback whales exhibit site fidelity over periods of days to years? Do humpback whales congregate in specific high-traffic and/or high-use U.S. Navy training areas? Do humpback whales spend significant time within or move through areas of U.S. Navy live-fire and mine neutralization exercise (MINEX) training?

Navy Marine Species Observers (MSOs) monitored UNDET training exercises at the Pu‘uloa Underwater Range, located west of the Pearl Harbor entrance channel, on 2 and 4 April 2013. The intent of the exercises was to provide training in precision cutting for harbor clearance or salvage. The primary purpose of the MSO presence was to monitor mitigation measures conducted by Mobile Diving and Salvage Unit 1 (MDSU-1); however, visual surveys were also conducted opportunistically.

The endangered North Atlantic humpback whale (Megaptera novaeangliae) migrates from six northern feeding grounds in the Gulf of Maine, the Gulf of St. Lawrence, Newfoundland/ Labrador, western Greenland, Iceland, and Norway to Caribbean Sea waters during the winter months (Katona and Beard 1990, Christensen et al. 1992, Palsbøll et al 1997). Understanding the occurrence and behavior of humpback whales in the vicinity of United States (U.S.) Navy training and vessel-transiting activities off the coast of Virginia is important in mitigating potentially harmful impacts on the species.

A total of 22 nearshore and mid-shelf vessel surveys were completed during the 2024/25 field season. In total, 60 baleen whale sightings, including 40 sightings of humpback whales (Megaptera novaeangliae) totaling 59 individuals, 10 sightings of North Atlantic right whales (NARWs; Eubalaena glacialis) totaling 22 individuals, 7 sightings of fin whales (Balaenoptera physalus) totaling 14 individuals, and 3 sightings of individual minke whales (Balaenoptera acutorostrata), occurred during the 2024/25 field season. A total of 24 aerial surveys were flown during the 2024/25 field season in association with this effort and the Offshore Cetacean Study (OCS) (A. Engelhaupt et al. 2026); see Ozog and Engelhaupt 2026 for additional details regarding the aerial surveys. Baleen whale sightings from the aerial surveys included humpback (n=45), NARWs (n=8), fin (n=11), and minke (n=3) whales (Ozog and Engelhaupt 2026). During the OCS surveys, baleen whale sightings included fin whales (n=12), humpback whales (n=7), a blue whale (Balaenoptera musculus; n=1), a minke whale (n=1), and an NARW (n=1) (A. Engelhaupt et al. 2026). Across this project and the OCS effort, satellite-linked telemetry tags were deployed on one humpback whale, one fin whale, and one NARW. Customized Animal Tracking Solution tags were deployed on two NARWs and two humpback whales. One biopsy sample was collected from the satellite-tagged humpback whale.

Since January 2015, HDR Inc. has been monitoring humpback whales (Megaptera novaeangliae) to assess their occurrence, habitat use, and behavior within and near United States (U.S.) Navy training and testing areas off Virginia via the Mid-Atlantic Humpback Whale Monitoring Project.

Since January 2015, HDR Inc. has been monitoring humpback whales (Megaptera novaeangliae) to assess their occurrence, habitat use, and behavior within and near United States (U.S.) Navy training and testing areas off Virginia via the Mid-Atlantic Humpback Whale Monitoring Project.

From December 2015 to February 2017, 35 satellite tags were deployed on humpback whales to gain a better understanding on the occurrence, movements, site-fidelity, and overall behavior of this species within this high-traffic region.

This study investigates mixed-species associations among marine mammals in the Southern California Bight, focusing specifically on Risso's dolphins (Grampus griseus). Over a six-year period, aerial surveys were conducted to record the frequency and nature of these associations, revealing that Risso's dolphins were the most commonly observed species in mixed interactions. The results indicate a significant decline in the proportion of Risso's dolphins involved in such associations compared to historical records, possibly due to an increase in their relative abundance. The findings underline the importance of monitoring mixed-species associations to understand marine mammal dynamics and ecological interactions.

As part of the long-term United States (U.S.) Navy-funded Marine Species Monitoring Program, from 11–19 February 2024, Cascadia Research Collective (CRC) carried out a vessel-based field effort in conjunction with passive acoustic monitoring undertaken by the U.S. Navy (Navy) scientists on and around the underwater hydrophone ranges of the Pacific Missile Range Facility (PMRF). The effort was timed to occur immediately prior to the start of a Submarine Command Course (SCC) to allow for collection of movement and dive data that could be used to examine exposure and response of cetaceans to Navy mid-frequency active sonar (MFAS; see Henderson et al. 2021). Eight days of field effort were funded by the Navy, and one day of field work was funded by National Oceanic and Atmospheric Administration (NOAA) Fisheries. Wildlife Computers SPLASH10-F satellite tags were funded by the Navy for deployment on Navypriority species, and additional tags were provided by Wildlife Computers or CRC for deployment on other species (e.g., humpback whales [Megaptera novaeangliae]). Tags were programmed to collect dive behavior and Fastloc®-Global Positioning System (GPS) data from the time deployed until three and a half days after the end of the SCC and continue to transmit the dive and Fastloc®-GPS data for an additional six days. Starting on either May 2nd or May 3rd, the tags were duty cycled to transmit only every second day, to provide longer-term tracks of individual movements. During the period that tags were collecting dive and Fastloc®-GPS data, tags were programmed to try to obtain Fastloc®-GPS locations only for the 12 hours of the day when there were no or limited satellite overpasses. This programming change from previous Kauaʻi field efforts was taken to minimize temporal gaps in location data during the period that overlapped with and immediately followed the SCC. Field efforts were undertaken out of Kikiaola small boat harbor when conditions allowed for working on or near PMRF, or out of Port Allen when conditions on or near PMRF were not workable.

A joint project in February 2015 on and around the Pacific Missile Range Facility (PMRF) was carried out utilizing combined boat-based field efforts and passive acoustic monitoring from the Marine Mammal Monitoring on Navy Ranges (M3R) system. There were 1,132 kilometers (63.4 hours [hr]) of small-vessel survey effort over the course of the 13-day project. Weather conditions precluded field operations on 4 days, and strong westerly winds and/or range operations limited access to PMRF on seven additional days, with only 15.1 percent of search time (9.6 hr) spent within the range boundaries.

As part of a long-term U.S. Navy-funded marine mammal monitoring program, in February 2020 a combination of vesselbased field effort and passive acoustic monitoring was carried out on and around the Pacific Missile Range Facility (PMRF) off Kaua‘i prior to a Submarine Command Course scheduled for mid-February 2020. The purpose of the monitoring effort was to assess the spatial movement patterns and habitat use of cetaceans that are exposed to midfrequency active sonar and how those patterns influence exposure and potentially responses. Results from this effort were compared with previous Cascadia Research Collective (CRC) survey effort and photo-identification and tag data from Kaua‘i, based on surveys in 11 different years since 2003.

The overall goal of this study was to include the 2018 survey data in the previous 1991–2014 modeling dataset in order to improve SMDs for the CCE study area. Specific objectives included: Generating multi-year average density surfaces for the Navy and others to use in their long-term (2–7 year) environmental planning efforts; and Providing updated abundance and “minimum population size (Nmin)” estimates as defined in the Guidelines for Assessing Marine Mammal Stocks (National Oceanic and Atmospheric Administration 2016).

The objectives of our study were two-fold: (1) develop spatially-explicit density estimates for winter/spring to support management applications, and (2) compare model-predicted density and distribution patterns to previously developed summer/fall model results in the context of species ecology. We used a well-established Generalized Additive Modeling framework to develop cetacean SDMs based on 20 California Cooperative Oceanic Fisheries Investigations (CalCOFI) shipboard surveys conducted during winter and spring between 2005 and 2015.

For the period of funding, Dr. Will Gough has been working at the Marine Mammal Research Program (MMRP) on a number of goals that will build capacity within Hawaii and advance the Navy’s goals related to the long-term health of protected marine mammal species. These goals relate to Dr. Gough’s expertise working with accelerometry-based biologging tags and include: setting up infrastructure at the MMRP to maintain large quantities of tag data, collecting novel data and expanding existing datasets through field efforts, training members of the Navy and MMRP to work effectively with accelerometry data and biologging devices, develop training materials and short-form workshops to disseminate knowledge of accelerometry data processing and analysis more broadly within the Hawaiian community, and use new and existing datasets to answer questions of relevance to the Navy and other organizations tasked with monitoring and management of protected species.

The National Oceanic and Atmospheric Administration (NOAA) Alaska Fisheries Science Center has maintained passive acoustic recorder moorings in areas of interest to the US Navy in the Gulf of Alaska (GOA). Archival data from three of these sites were analyzed for the timing and occurrence of key cetacean species. In addition, three subsurface passive acoustic moorings were deployed for a year (fall 2023 to fall 2024) in areas of mutual interest to NOAA and the Navy. Two of these new moorings, located along the western GOA slope, were redeployed in 2024.

The Hawaiian Islands Cetacean and Ecosystem Assessment Survey (HICEAS) is a recurring ship-based, line-transect survey designed to estimate cetacean abundance in the entirety of the Hawaiian EEZ.

Humpback whales (Megaptera novaeangliae) exhibit maternally driven fidelity to feeding grounds, and yet occasionally occupy new areas. Humpback whale sightings and mortalities in the New York Bight apex (NYBA) have been increasing over the last decade, providing an opportunity to study this phenomenon in an urban habitat. Whales in this area overlap with human activities, including busy shipping traffic leading into the Port of New York and New Jersey. The site fidelity, population composition and demographics of individual whales were analysed to better inform management in this high-risk area. Whale watching and other opportunistic data collections were used to identify 101 individual humpback whales in the NYBA from spring through autumn, 2012–2018.

The present study provides new and current estimates of cetacean density for the six most commonly encountered cetacean species off southern California based on sighting data collected during 37 quarterly CalCOFI cruises from 2004 to 2013. The current study resulted from a high survey repetition rate that allowed for the examination of inter-annual and seasonal trends in density as well as temporal and spatial patterns of distribution for six common cetacean species off southern California: blue whales, fin whales, humpback whales, short-beaked common dolphins, Pacific white-sided dolphins, and Dall’s porpoise.

Cetacean distribution, density and abundance in the Southern California Bight were assessed through visual and acoustic surveys during five California Cooperative Oceanic Fisheries Investigations (CalCOFI) cruises from August 2012-November 2013. Visual monitoring incorporated standard line-transect protocol during all daylight transits while acoustic monitoring employed a towed hydrophone array during transits and sonobuoys at oceanographic sampling stations. Visual effort included 584 observation hours covering 10,900 kilometers yielding 565 sightings of 15 identified cetacean species.

Spatial and temporal distribution patterns, density and abundance of cetaceans in the southern California Bight were assessed through visual and acoustic surveys during five California Cooperative Oceanic Fisheries Investigations (CalCOFI) cruises from August 2011 – July 2012. Visual monitoring incorporated standard line-transect protocol during all daylight transits while acoustic monitoring employed a towed hydrophone array during transits and sonobuoys at oceanographic sampling stations.

This report summarizes small boat based research conducted on cetaceans off southern California by the Scripps Institution of Oceanography (SIO) in collaboration with Southwest Fisheries Science Center (SWFSC) from August 2009 – July 2010. The primary objectives of this research were to use sighting, photo-identification, biopsy and acoustical sampling techniques to assess the occurrence, distribution and population structure of small cetaceans in a region that is subject to frequent naval exercises; this information is needed to evaluate possible effects from Mid Frequency Active Sonar (MFAS) trials and ultimately for the development of appropriate management protocols.

Trends in cetacean density and distribution off southern California were assessed through visual line-transect surveys during thirty-seven California Cooperative Oceanic Fisheries Investigations (CalCOFI) cruises from July 2004–November 2013. From sightings of the six most commonly encountered cetacean species, seasonal, annual and overall density estimates were calculated. Blue whales (Balaenoptera musculus), fin whales (Balaenoptera physalus) and humpback whales (Megaptera novaeangliae) were the most frequently sighted baleen whales with overall densities of 0.91/1000km2 (CV=0.27), 2.73/1000km2 (CV=0.19), and 1.17/1000km2 (CV=0.21) respectively. Species specific density estimates, stratified by cruise, were analyzed using a generalized additive model to estimate long-term trends and correct for seasonal imbalances. Variances were estimated using a non-parametric bootstrap with one day of effort as the sampling unit. Blue whales were primarily observed during summer and fall while fin and humpback whales were observed year-round with peaks in density during summer and spring respectively. Short-beaked common dolphins (Delphinus delphis), Pacific white-sided dolphins (Lagenorhynchus obliquidens) and Dall’s porpoise (Phocoenoidesdalli) were the most frequently encountered small cetaceans with overall densities of 705.83/1000km2 (CV=0.22), 51.98/1000km2 (CV=0.27), and 21.37/1000km2 (CV=0.19) respectively. Seasonally, short-beaked common dolphins were most abundant in winter whereas Pacific white-sided dolphins and Dall’s porpoise were most abundant during spring. There were no significant long-term changes in blue whale, fin whale, humpback whale, short-beaked common dolphin or Dall’s porpoise densities while Pacific white-sided dolphins exhibited a significant decrease in density across the ten-year study. The results from this study were fundamentally consistent with earlier studies, but provide greater temporal and seasonal resolution. Keywords: Cetaceans; Line transect; Density; Abundance; Distribution; Trends; Southern California; CalCOFI

The first cetacean circovirus, beaked whale circovirus (BWCV), was recently reported in a Longman’s beaked whale (Indopacetus pacificus) stranded in Hawai‘i and represents an emergent disease with unknown population impacts. In other species, circovirus infection may cause mortality or opportunistic co-infection by other pathogens. We report on a targeted surveillance of stranded cetaceans in the Pacific basin, including archived beaked whale species, strandings where pathological findings suggested disease presence, mass stranded animals, and additional individuals to represent a broad range of Hawaiian cetacean species. Archived tissues primarily from the brain, kidney, liver, lung, spleen, and lymph nodes of individuals stranded between 2000 and 2020 (n=30) were tested by PCR for the presence of BWCV.

This project is intended to provide baseline information on the species composition, density, distribution, and basic behavior of marine mammals and sea turtles present within the United States (U.S.) Navy’s Virginia Capes (VACAPES) Operating Area (OPAREA). This study is part of a larger, multi-institutional, marine mammal and sea turtle monitoring program of U.S. Navy range complexes along the U.S. Atlantic Coast and Gulf of Mexico supporting Atlantic Fleet Training and Testing (AFTT)

This survey implemented visual line transect and passive acoustic methods to assess the presence and distribution and to estimate density and abundance of cetaceans in Behm Canal and central Clarence Strait.

This report forms part of a multi-institutional monitoring project intended to provide information on the species composition, population identity, density, and baseline behavior of marine mammals and sea turtles present in United States (U.S.) Navy range complexes along the U.S. Atlantic Coast.

This study assesses the acoustic presence of humpback (Megaptera novaeangliae), sei (B. borealis), fin (B. physalus), and blue whales (B. musculus) over a decade, based on daily detections of their vocalizations.

In order for the U.S. military to conduct readiness training with the Mariana Island Training and Testing Study Area (MITT), including the area around Farallon de Medinilla (FDM), the Navy is required to monitor potential impacts of these activities on Marine Mammal Protection Act and Endangered Species Act-listed species. Humpback whales belonging to the North Pacific population are known to use portions of the MITT seasonally for breeding activities, specifically Marpi Reef and shallow waters around Saipan. A small-vessel visual survey for humpback whales was conducted between 29 January 2020 and 1 February 2020 to better understand the use of shallow-water habitat around FDM

Aerial shoreline surveys following U.S. Navy (Navy) training events were conducted in the Hawaii Range Complex to monitor for strandings and to document sightings of marine mammals and sea turtles in an effort to answer the monitoring question: “Do marine mammals strand along shorelines of the Main Hawaiian Islands (MHI) within 1 week following Navy training events?” This report summarizes marine mammal and sea turtle sighting data obtained during 67.5 hours of aerial survey effort over 16 days in the MHI between 2010 and 2014.

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).

Cetacean distribution, density and abundance in the Southern California Bight were assessed through visual and acoustic surveys during eighteen California Cooperative Oceanic Fisheries Investigations (CalCOFI) cruises from February 2012-April 2016. Visual monitoring incorporated standard line-transect protocol during all daylight transits while acoustic monitoring employed a towed hydrophone array during transits and sonobuoys deployed at oceanographic sampling stations. Visual effort included 2,031 observation hours covering 31,807 kilometers. A total of 1,914 sightings were made, which included 18 different cetacean species. Acoustic effort included 1m027 sonobuoy deployments and 478 towed array deployments.

Passive acoustic monitoring was conducted in the Navy’s Southern California Range Complex from December 2012 to January 2014 to detect marine mammal and anthropogenic sounds. High-frequency Acoustic Recording Packages (HARPs) recorded sounds between 10 Hz and 100 kHz at three locations: near Santa Barbara Island (880 m), west of San Clemente Island (1000 m), and southwest of San Clemente Island (1300 m). Six baleen whale species were recorded: blue whales, Bryde’s whales, fin whales, gray whales, humpback whales, and minke whales.

Passive acoustic monitoring was conducted in the Navy’s Southern California Range Complex from January to July 2014 to detect marine mammal and anthropogenic sounds. High-frequency Acoustic Recording Packages (HARPs) recorded sounds between 10 Hz and 100 kHz at three locations: west of San Clemente Island (1,000 m depth, site H), southwest of San Clemente Island (1,200 m depth, site N), and west of La Jolla, California (550 m depth, site P). Sites H and N are located offshore, whereas site P is located nearer to the coast.

High-frequency Acoustic Recording Packages (HARPs) were deployed from May 2013 to August 2014 to detect marine mammal and anthropogenic sounds in the Navy’s Jacksonville Range Complex. The HARPs recorded sounds between 10 Hz and 100 kHz at a site located 60 nm east off the Florida coastline on the continental shelf. Technical malfunctions resulted in loss of data for the period from June 8, 2013 through February 16, 2014. Data analysis consisted of analyst scans of long-term spectral averages (LTSAs) and spectrograms, and automated computer algorithm detection when possible. Three frequency bands were analyzed for marine mammal vocalizations and anthropogenic sounds: (1) Low-frequency, between 10300 Hz, (2) Mid-frequency, between 10-5,000 Hz, and (3) High-frequency, between 1-100 kHz. Three baleen whale species were detected: fin whales, humpback whales, and minke whales. Fin whale detections were limited to February 2014. Humpback whale calls were detected from February to June 2014 with a peak in March 2014. Minke whales were detected in late-February through March 2014. An additional sound called the 5-pulse signal, presumably from a baleen whale, was detected from February to September 2014, with a peak in July. One known odontocete species was detected, Risso’s dolphins, which were detected in low numbers in July 2014. Odontocete signals that could not be distinguished to species were common throughout the recordings. However, eight distinct click types of unknown species origin were found to be present (CT 17, CT 22, CT 25, CT 26, CT 27, CT 27A, CT 30 and CT32). The following anthropogenic sounds were detected: broadband ship noise, Mid-Frequency Active (MFA) sonar, and echosounders. Broadband ships were common throughout the recordings with a peak in detections in May 2014. MFA sonar was detected during all months with recordings, with a peak in June 2013. Echosounder pings were prevalent throughout the recordings.

Passive acoustic monitoring was conducted at two sites in the US Navy’s Jacksonville Range Complex during August 2010 – July 2011. These sites are located 50 and 61 nm east of the Florida coastline on the shelf and shelf break at water depths of 40 m – 90 m. Acoustic data collected at these sites provide information on the presence of marine mammals and anthropogenic sound sources. High-frequency Acoustic Recording Packages (HARPs) documented sounds between 10 Hz and 100 kHz with recording cycles of 5 minutes every 15 minutes. The data were divided into three frequency bands and data analysis was conducted with analyst scans of long-term spectral averages and spectrograms. Four mysticete whale species were recorded: fin, minke, sei, and humpback. No blue whale, North Atlantic right whale, or Bryde’s whale calls detected. A new call, designated the “5-pulse” was detected and is presumed to be produced by a mysticete whale due to its character, prevalence and intensity. Site A has more hours with calling mysticete whales than site B. However, humpback whale calls were detected only at site B, though these detections were few. The largest number of odontocete detections were attributed to unidentified odontocetes, thought to be primarily bottlenose and Atlantic spotted dolphins. Unidentified odontocetes were detected throughout the year. Overall numbers of detections were higher at site A than site B. There was a diel acoustic activity pattern with greater numbers of echolocation clicks produced at night, likely due to nighttime foraging. Risso’s dolphin echolocation clicks were only detected at site A and only occurred August through March. Five click types, yet to be associated to an odontocete species, were characterized and their seasonal and diel occurrence described. Ship noise was the most common anthropogenic sound at both sites A and B. Both sites had Mid-Frequency Active (MFA) sonar events throughout the period of data collection. At site A, a total of 2,437 MFA sonar pings were detected with a maximum peak-to-peak received level of 173 dB re 1 μPa. Similarly, a total of 2,496 MFA sonar pings were detected at site B, reaching a maximum peak-to-peak level of 166 dB re 1 μPa. Echosounder pings with a variety of primary frequencies (4 – 80 kHz) were found at both sites A and B. Explosions were recorded at both sites, though were more prevalent at site B. A low-frequency tone, referred to as the 130 Hz tone, was recorded at site A. High noise levels, possibly caused by instrument strumming and fluid flow at the sensor, occurred intermittently at both sites and likely decreased the detection range for low-frequency sounds.

Navy Research Funded Year Three Project Reports

In order to train with mid-frequency active sonar (MFAS), the United States (U.S.) Navy has obtained a permit from the National Marine Fisheries Service (NMFS) under the Marine Mammal Protection Act (MMPA) and a Biological Opinion under the Endangered Species Act (ESA). The Navy has developed Monitoring Plans for individual Navy Range Complexes, guided by the Integrated Comprehensive Monitoring Program (ICMP), to provide marine mammal and sea turtle monitoring guidelines as required under the MMPA and the ESA (Department of the Navy 2010). The Hawaii Range Complex (HRC) Monitoring Plan, implemented in 2014, was developed with NMFS to comply with the requirements under the permits (Department of the Navy 2014). The ICMP provides the overarching framework for coordination of the U.S. Navy Monitoring Program (Department of the Navy 2010). The ICMP outlines objectives for range/project-specific Monitoring Plans and U.S. Navy-funded research relating to the effects of naval training and testing activities on protected marine species (Department of the Navy 2010).

In the Pacific, the Marine Mammal Monitoring on Navy Ranges (M3R) program maintains systems that continuously run algorithms to detect, classify and localize marine mammals year-round on the U.S. Navy’s deep-water Southern California Antisubmarine Warfare Range (SOAR) in Southern California and the Pacific Missile Range Facility (PMRF) off Kaua‘i, Hawai‘i. Long-term archive data collected on these ranges allow for numerous types of studies on species inhabiting the ranges, including the monitoring of abundance, behavioral responses to naval activities, and habitat usage. They also provide the opportunity to study ambient sound levels and soundscapes.

Documenting year-round diversity and distribution of marine mammals off Southern California is important for assessment of effects of potentially harmful anthropogenic activities. Although the waters off Southern California have been surveyed extensively for marine mammals over the past 18 years, such surveys have been periodic and were conducted primarily from summer to fall, thereby missing potential seasonal shifts. We examined seasonal abundance and population density of cetaceans off Southern California from 16 shipboard line-transect surveys conducted quarterly during 2004–08. The study area consisted of 238,494 km² of coastal, shelf, and pelagic oceanic habitat from near-shore waters to 700 km offshore.

Taking into consideration the multiple intermediate scientific objectives in the U.S. Navy’s Strategic Planning Process (DoN 2013), the goals of this study are to assist the U.S. Navy and regulatory agencies with environmental planning and compliance by addressing the following questions: Which cetacean species occur within the VACAPES OPAREA off Virginia, and how does occurrence fluctuate seasonally? What are the baseline behaviors and ecological relationships of offshore cetaceans within the study area? Do individual cetaceans exhibit site fidelity within specific regions of the study area over periods of weeks, months, or years? What is the seasonal extent of cetacean movements within and around U.S. Navy VACAPES training range boxes? Do cetaceans spend significant time within or primarily move through areas of U.S. Navy live-fire or Anti-Submarine Warfare training events?

The United States (U.S.) Navy routinely conducts training and testing activities in the Virginia Capes (VACAPES) Operating Area (OPAREA) off the mid-Atlantic and Southeast U.S. The region encompassing the deeper waters of the continental shelf, shelf break, and continental slope has been recognized as an important habitat for multiple species of cetaceans. Kenney and Winn (1986) showed that the shelf edge from Cape Hatteras to Georges Bank was the second most intensively used cetacean habitat off the northeastern U.S. based on 3 years of surveys conducted by the Cetacean and Turtle Assessment Program (CETAP 1982). This progress report includes all offshore monitoring activities conducted in 2021. The goals of this effort focus on addressing fundamental information gaps related to marine mammal occurrence, exposure, and response as identified by the U.S. Navy’s Integrated Comprehensive Monitoring Program (DoN 2010) and recommendations provided by a Scientific Advisory Group review (DoN 2011).

Taking into consideration the multiple intermediate scientific objectives in the U.S. Navy’s Strategic Planning Process (DoN 2013b), the goals of this study are to assist the U.S. Navy and regulatory agencies with environmental planning and compliance by addressing the following questions: • Which cetacean species occur over the outer continental shelf to the east of NSN, and how does occurrence fluctuate seasonally? • What are the baseline behaviors and ecological relationships of offshore cetaceans within the study area? • Do individual cetaceans exhibit site fidelity within specific regions of the study area over periods of weeks, months, or years? • What is the seasonal extent of cetacean movements within and around U.S. Navy VACAPES training range boxes? • Do cetaceans spend significant time within or primarily move through areas of U.S. Navy live-fire or Anti-Submarine Warfare training events?

Taking into consideration the multiple intermediate scientific objectives in the U.S. Navy’s Strategic Planning Process (DoN 2013b), the goals of this study are to assist the U.S. Navy and regulatory agencies with environmental planning and compliance by addressing the following questions:  Which cetacean species occur over the outer continental shelf to the east of NSN, and how does occurrence fluctuate seasonally?  What are the baseline behaviors and ecological relationships of offshore cetaceans within the study area?  Do individual cetaceans exhibit site fidelity within specific regions of the study area over periods of weeks, months, or years?  What is the seasonal extent of cetacean movements within and around U.S. Navy VACAPES training range boxes?  Do cetaceans spend significant time within or primarily

Taking into consideration the multiple intermediate scientific objectives in the U.S. Navy’s Strategic Planning Process (DoN 2013b), the goals of this study are to assist the U.S. Navy and regulatory agencies with environmental planning and compliance by addressing the following questions:  Which cetacean species occur over the outer continental shelf to the east of NSN, and how does occurrence fluctuate seasonally?  What are the baseline behaviors and ecological relationships of offshore cetaceans within the study area?  Do individual cetaceans exhibit site fidelity within specific regions of the study area over periods of weeks, months, or years?  What is the seasonal extent of cetacean movements within and around U.S. Navy VACAPES training range boxes?  Do cetaceans spend significant time within or primarily

Taking into consideration the multiple intermediate scientific objectives in the U.S. Navy’s Strategic Planning Process (DoN 2013b), the goals of this study are to assist the U.S. Navy and regulatory agencies with environmental planning and compliance by addressing the following questions:  Which cetacean species occur over the outer continental shelf to the east of NSN, and how does occurrence fluctuate seasonally?  What are the baseline behaviors and ecological relationships of offshore cetaceans within the study area?  Do individual cetaceans exhibit site fidelity within specific regions of the study area over periods of weeks, months, or years?  What is the seasonal extent of cetacean movements within and around U.S. Navy VACAPES training range boxes?  Do cetaceans spend significant time within or primarily

Taking into consideration the multiple intermediate scientific objectives in the U.S. Navy’s Strategic Planning Process (DoN 2013), the goals of this study are to assist the U.S. Navy and regulatory agencies with environmental planning and compliance

A combination of visual line-transect survey, photo-identification (photo-ID), and automated acoustic monitoring methods is being used to gather important baseline information on the occurrence, distribution, and density of marine mammals near Naval Station Norfolk and adjacent areas. The study area was chosen to cover areas where United States (U.S.) Navy activity is substantial, including Chesapeake Bay waters near Naval Station Norfolk and Joint Expeditionary Base Little Creek-Fort Story, as well as a Mine Exercise (MINEX) Area (W-50) in the Atlantic off the coast of Virginia Beach, Virginia. Forty-seven line-transect surveys were completed in two zones (INSHORE and MINEX) between August 2012 and December 2014, with 5,106 kilometers (km) and 276.5 hours completed on-effort.

A combination of visual line-transect survey, photo-identification (photo-ID), and automated acoustic monitoring methods was used to gather important baseline information on the occurrence, distribution, and density of marine mammals near Naval Station Norfolk (NSN) and adjacent areas. The study area was designed to cover areas where United States Navy activity is substantial, including Chesapeake Bay waters near NSN and Joint Expeditionary Base Little Creek-Fort Story, as well as a Mine Exercise (MINEX) Area (W-50) in the Atlantic Ocean off the coast of Virginia Beach, Virginia

A combination of visual line-transect survey, photo-identification (photo-ID), and automated acoustic monitoring methods is being used to gather important baseline information on the occurrence, distribution, and density of marine mammals near Naval Station Norfolk (NSN) and adjacent areas. The study area was chosen to cover areas where United States (U.S.) Navy activity is substantial, including Chesapeake Bay waters near Naval Station Norfolk, Joint Expeditionary Base (JEB) Little Creek (LC), and JEB Fort Story, as well as a Mine Exercise (MINEX) Area (W-50) in the Atlantic off the coast of Virginia Beach, Virginia.

In order to train with mid-frequency active sonar (MFAS), the United States (U.S.) Navy has obtained a permit from the National Marine Fisheries Service (NMFS) under the Marine Mammal Protection Act. The Hawaii Range Complex (HRC) Monitoring Plan, finalized in December 2008 for implementation in January 2009, was developed with NMFS to comply with the requirements under the permit. The monitoring plan and reporting will provide science-based answers to questions regarding whether or not marine mammals are exposed and reacting to Navy MFAS. The objectives of the monitoring plan are to address the following questions: Are marine mammals and sea turtles exposed to MFAS at regulatory thresholds of harm or harassment? If so, at what levels and how frequently are they exposed? 1. If marine mammals and sea turtles are exposed to MFAS in the HRC, do they redistribute geographically in the HRC as a result of repeated exposure? If so, how long does the redistribution last? 2. If marine mammals and sea turtles are exposed to MFAS, what are their behavioral responses? Are they different at various levels? 3. What are the behavioral responses of marine mammals and sea turtles that are exposed to various levels and distances from explosives? 4. Are the Navy’s suite of mitigation measures for MFAS and explosives (e.g., Protective Measures Assessment Protocol [PMAP], measures agreed to by the Navy through permitting and consultation) effective at avoiding harm or harassment of marine mammals and sea turtles?

In order to address requirements under the Marine Mammal Protection Act Letters of Authorization permitted to the U.S. Navy, three U.S. Navy civilian marine mammal observers (MMOs; Ms. Amy Farak, Ms. Julie Rivers, and Dr. Robert Uyeyama) and one U.S. Navy contractor (Dr. Thomas A. Jefferson) participated in two consecutive ASW exercise events in the Hawaii Range Complex from 15‐22 February, 2011 (Figure 1). These MMOs were stationed aboard a U.S. Navy destroyer, hereafter referred to as DDG‐D. The goals of the monitoring and this study were to: 1. Collect data to assess the effectiveness of the Navy lookout team. 2. Obtain data to characterize the possible exposure of marine species to mid‐frequency active sonar (MFAS). 3. Achieve close coordination between the contracted aerial survey team, Navy aircraft on the range, range control, and th

This report summarizes the aerial survey effort conducted at the JAX site from 2009 through 2017. The monitoring project was intended to provide information on the species composition, density, and spatial distribution of marine mammals and sea turtles present in Navy’s JAX operating area (OPAREA), with particular focus on the intended site of the USWTR. These aerial surveys extended over nine years and yielded a very detailed seasonal picture of the occurrence, distribution and abundance of marine mammals and sea turtles in the region. This work also provides an important baseline against which future changes in the marine mammal and sea turtle fauna can be assessed.

A multi-institutional marine protected species monitoring program involving aerial, vessel and acoustic surveillance techniques was implemented at the proposed Undersea Warfare Training Range (USWTR) offshore of Jacksonville, Florida in January 2009. Visual surveys, in conjunction with acoustic sampling methods, have been conducted to investigate cetacean and sea turtle occurrence, distribution and abundance. Through December 2012 a total of 722 aerial tracklines (60687 km) were flown, resulting in 641 cetacean sightings, encompassing 8079 individuals. Tursiops truncatus and Stenella frontalis were the most frequently encountered, followed by Grampus griseus, Globicephala macrorhynchus, Balaenoptera acutorostrata, Steno bredanensis, Eubalaena glacialis, Megaptera novaeangliae, Physeter macrocephalus, and Kogia spp. Cetaceans were encountered 126 times during the 3403 km of vessel surveys, totaling 950 individuals. Sightings consisted of S. frontalis, T. truncatus, G. macrorhynchus, and G. griseus. Across all visual platforms, T. truncatus were encountered throughout the range, whereas S. frontalis, S. bredanensis, and E. glacialis were recorded exclusively in shelf waters. All other species were detected only in pelagic waters. The towed passive acoustic array was deployed during 21 vessel surveys, generating 24.2 hours of recordings, detecting all four sighted species. High frequency acoustic recording packages (HARPs) were deployed at two sites in the study area for long‐term passive acoustic monitoring. The HARP data have been analyzed for diel, seasonal, and interannual trends in cetacean occurrence. Surveys are scheduled to continue in order to asses long‐term habitat usage patterns in the USWTR.

A passive acoustic monitoring survey using mobile underwater gliders was conducted from 7 February to 31 March 2020 in the Southern California Bight, with the goal of characterizing the temporal and spatial distribution of odontocetes and mysticetes in the region. Initially, the focus of this Project was on beaked whales. However, upon recovery of the gliders post-deployment, it was discovered that neither glider recorded any useable data above 2.5 kilohertz, well below the frequency of beaked whale vocalizations. It was then decided to analyze the available data for baleen whale and sperm whale (Physeter macrocephalus) vocalizations, which was originally a focus of secondary importance for the Project.

Cetacean distribution and abundance are reported from the first systematic line-transect visual survey in the waters of Guam and the Commonwealth of the Northern Mariana Islands (CNMI). The survey was conducted during January–April 2007 following standard line-transect protocols. Trackline coverage (11,033 km) was dominated by high sea states (88.2%); however, 13 cetacean species were recorded.

Cetacean distribution and abundance are reported from the first systematic line-transect visual survey in the waters of Guam and the Commonwealth of the Northern Mariana Islands (CNMI). The survey was conducted during January–April 2007 following standard line-transect protocols.

Many animals increase the intensity of their vocalizations in increased noise. This response is known as the Lombard effect. While some previous studies about cetaceans report a 1 dB increase in the source level (SL) for every dB increase in the background noise level (NL), more recent data have not supported this compensation ability. The purpose of this study was to calculate the SLs of humpback whale song units recorded off Hawaii and test for a relationship between these SLs and background NLs.

This report presents the results of marine mammal monitoring for the Koa Kai 11‐1 training event, and represents the continued monitoring efforts under the U.S. Navy’s Marine Species Monitoring Program. The objectives of the vessel‐based monitoring effort for Koa Kai 11‐1 consisted of the following:  Perform focal behavioral follows of marine mammals during the course of a training event involving ASW. Assess the occurrence, distribution, and behavior of target species (marine mammals and sea turtles) using a vessel‐based line transect survey within the HRC in waters within or adjacent to the area where ships were training. Locate individual false killer whales (Pseudorca crassidens), pygmy killer whales (Feresa attenuata), and short‐finned pilot whales (Globicephala macrorhynchus) tagged by Dr. Robin Baird with Cascadia Research. Investigate the occurrence, distribution, and behavior of target species (marine mammals and sea turtles) using vessel‐based line transect survey in waters within or adjacent to the area where Navy ships were training

In order to support the U.S. Navy in meeting regulatory requirements for monitoring established under the Final Rules and to provide a mechanism to assist with coordination of program objectives under the ICMP, this survey was conducted to confirm the Marine Mammal Monitoring on Navy Ranges (M3R) acoustic detections and marine mammal satellite tagging was prior to a training event, the Submarine Commander’s Course exercise, which would be conducted in the same area during February 2012.This report presents the methods and preliminary results of a vessel-based visual and acoustic survey effort that was conducted in conjunction with a tagging and species-validation project

The overall objective of the ICMP is to assimilate relevant data collected across U.S. Navy range complexes in order to answer questions pertaining to the impact of MFAS and explosives on marine mammals and sea turtles.

The first phase to integrate the historical sum of these U.S. Navy-sponsored visual survey efforts for marine species monitoring in the HRC was prepared by Uyeyama (2011). This report represents the second phase of that effort and presents an overview of monitoring survey effort to date in the HRC. Available data from visual surveys performed by both contractor-led efforts and U.S. Navy in-house surveys was compiled and processed in order to: 1. Create a geographic information system (GIS)-based summation of all survey tracks that can be easily visualized. 2. Construct a geo-referenced database of sightings that can be queried by species, observer platform, Beaufort Sea State (BSS), season, or other sighting/survey variables. 3. Conduct an enhanced analysis of sighting success with respect to survey platform, field protocol, and environmental conditions. 4. Inform and adjust data collection procedures on future surveys as needed to reflect lessons learned from sighting data compilation efforts presented here. 5. Provide information to enhance informed management of marine protected species in the HRC and support the adaptive management process that is part of the ICM

This report presents a geographic information system (GIS)-based overview of the sighting records obtained during marine species monitoring effort (a total of 12 U.S. Pacific Fleet-funded surveys) to date in the MIRC. Also included are incidental marine mammal and sea turtle sightings made since 1965 on non-dedicated surveys in the region.

Time difference of arrival (TDOA) methods for acoustically localizing multiple marine mammals have been applied to recorded data from the Navy’s Pacific Missile Range Facility in order to localize and track humpback whales.

Beaked whales (Family Ziphiidae; Order Cetacea) are the least well-described group of marine mammals because they conduct very long deep dives, spend little time on the surface where they display cryptic behavior, and are difficult to identify due to the similarity between species. Beaked whales are also known to be susceptible to high-energy sound sources in the ocean (e.g. seismic research, sonars used by military activities).

In August 2023 and February 2024, Cascadia Research Collective (CRC) conducted small boat-based satellite tagging of odontocetes at the Pacific Missile Range Facility (PMRF), with acoustic support from Naval Information Warfare Center (NIWC) Pacific and Naval Undersea Warfare Center (NUWC) Newport, directing the tagging boat towards locations of acoustic detections on the range. Seventeen days of tagging effort were conducted over the two years during the biannual Submarine Command Course (SCC) training events. In total 19 odontocetes were tagged: 14 short-finned pilot whales (Globicephala macrorhynchus), 3 common bottlenose dolphins (Tursiops truncatus), 1 pantropical spotted dolphin (Stenella attenuata), and 1 melon-headed whale (Peponocephala electra). Additionally, 3 humpback whales (Megaptera noveangliae) were tagged in concert with this effort to test new tags, and that data was also analyzed herein

This report summarizes the field effort from 15 – 28 November, 2020, to locate and document a species of beaked whales that had previously only been acoustically detected. While the species of interest was again recorded on acoustic drift buoys, a previously undescribed species of beaked whale was unexpectedly encountered instead. This new species has external morphological characteristics and a new echolocation pulse type that do not match any previously observed or recorded species and therefore may represent a newly described species. In addition to this species of beaked whale, we encountered and photographed three species of dolphin as well as humpback whales, and recorded two other species of beaked whales on the acoustic recorders.

An expedition was conducted with the goal of visually locating, acoustically recording, and obtaining biopsy samples of the Mesoplodon beaked whales that were encountered in 2020 and produce BWB pulses, as well as locating the beaked whales that produce the BW43 echolocation pulse in order to conclusively determine what species produce each of the pulse types.

A Time Difference of Arrival (TDOA) method was used to acoustically localize singing humpback whales (Megaptera novaeangliae) on the US Navy's Pacific Missile Range Facility (PMRF) in Hawaii. 2090 hours of recorded data were collected during non-training event periods between September and June, 2011-2014. Eighty-one three-dimensional tracks were obtained with one to six tracks occurring on 42 separate days. The minimum detection rate occurred in January 2012 with 0.01 dives per hour of effort, and a maximum detection rate of 0.18 dives per hour of effort occurred in March 2011. Tracks were determined to fall into three behavioral categories - Travel, Localized Dive, and Mill. Metrics including bearing, directivity, speed, and dive depths were measured and compared between behavior categories, as well as across the breeding season. While the mean track bearings were not statistically different across months, the range of bearings was more restricted in December-February (152° - 250°, S-SW) than in March-May (114° - 346°, SE-NNW). Tracks of Travel behavior had the highest mean speed, longest distances, deepest dives, and the most direct path. Localized Dives had the least direct path and occurred over the shortest distances. Most tracks started and finished during the daytime period with some continuing into the night, but no tracks started and ended at night, indicating some diel periodicity to the behavior in this area. This analysis can provide valuable information about the habitat use of an offshore portion of humpback whale breeding grounds and the baseline behavior of humpback whales on a US Navy range.

In order to test the possibility of using high frequency pinger tags to track baleen whales on Navy instrumented ranges, three blue (Balaenoptera musculus) and one humpback (Megaptera novaeangliaea) whales were exposed to two high frequency pingers. The pinger frequencies were 37 and 45 kHz, with estimated received levels between 106 and 134 dB re 1 lPa. The whales were monitored prior to the exposure in order to establish their behavioral state and to acclimate them to the presence of the boat. Two of the blue whales were deep feeding, while the third blue whale and the humpback whale were traveling with intermittent bouts of possible foraging near the surface. Each exposure lasted approximately 30—40 minutes, and the whales were observed for an additional two to three surfacing intervals post-exposure. None of the blue whales demonstrated any behavioral response. The humpback whale’s response was inconclusive, as other foraging animals entered the area at the same time; however, it is likely there was no response. These data may begin to provide information on the upper frequency limits of baleen whale hearing, as these species have responded to Navy sonar-like sounds at lower frequencies but similar received levels and behavioral states.

Humpback whales Megaptera novaeangliae encountered off the island of Kaua’i, Hawai’i, USA, in 2017, 2018, and 2019 were photo-identified, and 19 whales were equipped with satellite telemetry tags to track their inter-island movements and use their movement behavior to estimate when and where the whales changed their behavior from breeding to migration. Fluke photographs were matched in the online photo-ID repository HappyWhale to track individual observation histories and movement records within the islands and on their way to their feeding grounds. Tag attachment periods were relatively short, with transmissions lasting 1.6-12.5 d. Movement behavior models were developed using hidden Markov models; whales in proximity to land were found to remain in area-restricted search or an intermediate behavior state, while whales that moved between islands or offshore tended to transition into directed travel behavior. Movement patterns and routes were similar between animals and across years, particularly when they transited between Kaua’i and O’ahu and began migrating from Ni’ihau to the first seamounts of the northwestern Hawaiian Islands. Dive data were also analyzed in association with the movement behavior. Whales that transited between Kaua’i and O’ahu as well as those in offshore waters conducted repeated series of deep (>100 m) dives only at night, whereas whales that remained in nearshore waters conducted less frequent and less deep dives day or night. These results provide insight into the inter-island movements and behavior of humpback whales while on the Hawaiian breeding grounds as well as where and how their behavior transitioned into migration.

This paper describes a unique situation in which four of the seven members of a competitive group were tagged with Wildlife Computers SPLASH10 F-333 tags and their dive behavior was recorded for a large portion of the encounter. In addition, the primary escort and nuclear animal (referred to as the female from here on) remained together for at least 4 days before the tag on the female stopped transmitting. The location, movement behavior, and dive behavior of these two whales were highly correlated. The events of the competitive pod encounter are detailed herein, with a focus on the dive behavior of the four tagged whales, along with a description of the movement and dive behavior of the primary escort and female during their 4-day association.

Marine mammal surveys, initiated as part of the CalCOFI cruises in 2004, were continued during 2016-2017. Visual monitoring incorporated standard line-transect survey protocol which includes two experienced observers scanning for marine mammals during transits between CalCOFI stations.

Passive acoustic monitoring was conducted in the Navy’s Southern California Range Complex during May 2011 – March 2012 to detect the presence of marine mammal and anthropogenic sounds. Highfrequency Acoustic Recording Packages (HARPs) recorded sounds between 10 Hz and 100 kHz with nearly continuous temporal coverage at a site near Santa Barbara Island (site M) and at a site west of San Clemente Island (site H). Data analysis consisted of detection of sounds of interest by analyst scans of long-term spectral averages and spectrograms, and by automated computer algorithm detection when possible. Representative sounds are presented in this report, as well as details of the computer algorithms used to detect them.