Primary objectives of this project have included the following: Collect baseline occurrence data (location, sex, group size, behavior) of humpback whales (and other species of baleen whales, opportunistically), Obtain identification photographs of humpback whales for inclusion in regional and local catalogs, Collect biopsy samples of humpback whales for sex determination, mitochondrial control region sequencing and microsatellite genotyping of tissue samples, and stable isotope analysis to assess foraging related to prey consumption • Conduct satellite tagging to document seasonal humpback whale movement patterns in the nearshore waters off Virginia Beach, specifically whether the whales spend significant time in areas of high shipping traffic and/or areas of U.S. Navy training exercises

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.

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.

Baseline undisturbed behavior and social patterns of blue (Balaenoptera musculus) and fin whales (B. physalus) are not well described and are needed to identify and understand potential effects of anthropogenic activities. Behavioral data for blue and fin whales were collected during line-transect and focal-follow effort. Initially observed behavior state, heading, and minimum and maximum interindividual dispersal distance were recorded during line-transect sampling. Focal groups were circled for 10-60+ minutes and videotaped from outside Snell’s sound cone to avoid disturbance. During 24,736 km of survey effort, 51 fin whale sightings (85 individuals) and 49 blue whalesightings (81 individuals) were seen. Over 7 hours of video was collected for16 blue and 15 fin focal follows. During the summer seasons, blues (n=48) were seen more commonly than fins (n=35); in fall, fins (n=16) were seen significantly more frequently than blues (n=1). Mean group size was 1.7 whales for both species. Initially observed blue behavior was usually travel (85%) or mill (11%). Observed fin whale behavior was also mostly travel (90%), mill (4%), or surface-active travel (4%). Both species were seen socializing in fall but not summer; foraging was observed in summer through fall. Mean initial dispersal for blues and fins was 9.1 and 14.2 body lengths, respectively. In summer, blues were most frequently (26%) seen headed S; in fall (n=2), they were headed only inshore (E). In summer, fin whales were most commonly headed SSW (26%) or WNW (26%); in fall, they were headed mostly NE (38%) or WSW (38%). Dive/respiration/behavioral event rates were also collected. Both species may directly compete for food based on observations of inter-specific maneuvering for a bait ball. Data represent the most extensive record of systematic undisturbed behavior on these species in SOCAL and include social interactions not previously documented in this region.

Baseline undisturbed behavior and social patterns of blue (Balaenoptera musculus) and fin whales (B. physalus) are not well described and are needed to identify and understand potential effects of anthropogenic activities in the SCB. In 2008-2012, 72,467 km of aerial line transect and focal-follow effort was conducted in the SCB. Initially observed location, group size, behavior state, heading, and minimum and maximum inter-individual dispersal distance were recorded. Focal groups were circled for 10-60+ minutes and videotaped from outside the plane’s sound cone to avoid disturbance. A total of 122 fin whale sightings (208 individuals) and 65 blue whale sightings (104 individuals) were made. Behavior, occurrence and distribution were related to season, location, bathymetry, and time of day. Blue whales were seen only from summer-fall and concentrated primarily close to shore (

Baseline undisturbed behavior/social patterns of blue/fin whales are not well described and are needed to identify and understand potential effects of anthropogenic activities. Behavioral data were collected during aerial effort. Initially observed behavior state, heading, minimum/maximum inter-individual dispersal distance were recorded during line-transect sampling. During the summer seasons, blues were seen more than fins; in fall, fins were seen more. Initially observed blue behavior was usually travel or mill. Observed fin behavior was mostly travel, mill, or surface-active travel. Both species were seen socializing in fall but not summer; foraging was observed in summer through fall. In summer, blues were seen headed S; in fall, headed inshore. In summer, fins were headed SSW or WNW; in fall, they were headed NE or WSW. Data represent the most extensive record of systematic undisturbed behavior on these species in SOCAL and include social interactions not previously documented in this region.

Baseline undisturbed behavior and social patterns of blue (Ba/aenoptera musculus) and fin whales (8. physa/us) are not well described and are needed to identify and understand potential effects of anthropogenic activities. Behavioral data for blue and fin whales were collected during aerial survey line-transect and focal-follow effort. Initially-observed behavior state, group size, heading, and minimum and maximum inter-individual dispersal distance were recorded during line-transect sampling and / or subsequent verification circling by the aircraft. Focal groups were circled for 3- 60+ minutes and videotaped from outside Snell's sound cone to avoid disturbance. During 24,736 km of survey effort, 51 fin whale sightings (86 individuals) and 49 blue whale sightings (84 individuals) were seen . Over 7 hours of video was collected for 16 blue and 15 fin focal follows. During the summer, blues (n=48) were seen more commonly than fins (n=35); in fall, fins (n=16) were seen much more frequently than blues (n= 1 ). Mean group size was 1. 7 whales for both species. Initially observed blue behavior was usually travel (85%) or mill (11%). Observed fin whale behavior was also mostly travel (87%), mill (6%), or surface-active travel (3%). Both species were seen socializing (e.g., touching) in fall but not summer; foraging was observed in summer through fall. Mean initial dispersal for blues and fins was 8 and 16 body lengths, respectively. In summer, blues were most frequently (26%) seen headed S; in fall (n=2), they were headed only inshore (E). In summer, fin whales were most commonly headed SSW (26%) or WNW (26%); in fall, they were headed mostly NE (38%) or WSW (38%). Both species directly compete for food based on observations of inter-specific maneuvering for a bait ball. Data represent the most extensive record of systematic undisturbed behavior on these species in SOCAL and include social interactions not previously documented in this region. Dive / respiration / behavioral event rates were also collected and are currently being analyzed. Bacon, C., M.A. Smultea, B. Wursig, K. Lomac-MacNair, and J. Black.

Effects of mixed-species associations (MSA [at least two different species swimming together and / or inte racting]) on cetacean behavior rarely have been quantified, but are important for identifying and differentiating potential anthropogenic impacts . Baseline marine mammal behavior was assessed during 83 ,005 km of U.S. Navy supported aerial line-transect surveys in the Southern California Bight during 2008-2013.

Effects of mixed-species associations (MSA [at least two differentspecies swimming together and/or interacting]) on cetacean behavior rarely have been quantified, but are important for identifying and differentiating potential anthropogenic impacts. Baseline marine mammal behavior was assessed during 77,390 km of U.S. Navy supported aerial line-transect surveys in the Southern California Bight during 2008-2013. Multinomial logistic regression was used to assess effects of MSA on group size, maximum nearest neighbor distance (a “cohesion” index, in body lengths), behavior state, and heading. Two percent (43) of 2,330 sightings were MSA involving 13 species (5 baleen whales, 7 toothed whales, 1 pinniped). Behavior and group size of some species differed significantly in MSA vs. non-MSA. MSA were predominated by Risso’s dolphins (44%; 19 of 43 MSA). Risso’s dolphins were most frequently associated with bottlenose dolphins (37% of 19 Risso’s MSA groups) followed by northern right whale dolphins (NRWD; 3% of 19). Risso’s dolphins tended to change headings more often in MSA (p

Rapid progress and affordability of photographic technology with increasing improvements in image resolution have facilitated advancements in efficiency and alternative approaches in data collection for marine mammals. We report these recent improvements by comparing marine mammal photographs taken during 2008-2013 aerial surveys of 16 marine mammal species in the Southern California Bight, shorebased studies of bottlenose dolphins (Tursiops truncatus) in Galveston Bay, Texas (2011-2013), and gray whales (Eschrichtius robustus) off Sakhalin Island, Russia (20042010). Various Canon and Nikon high-definition cameras ranging from 8.2-36.3 MP resolution and 70-1600 mm lenses with image stabilization were used during the studies. Results of these photographic comparisons demonstrate the evolution of digital photography advancements with the successful capture of individuals, as well as detailed information for behavioral ecology studies. For example, (1) individual identification of marine mammal species from aircraft not previously reported (Risso’s dolphins (Grampus griseus), killer whales (Orcinus orca), and blue and fin whales (Balaenoptera musculus and B. physalus)), (2) shore-based individual identification of bottlenose dolphins up to 500 m and of gray whales up to 2 km from shore, (3) instantaneous differentiation/confirmation of short-beaked vs. long-beaked common dolphins (Delphinus delphis and D. capensis) from 1,500-ft altitude with a 36 MP camera, (4) reduced proportion of “unidentified” dolphin and whale species, and (5) potential tracking of the behavior, social associations and durations, and relative position within the group of some individually identified delphinids and other species not previously studied in this manner. High- definition digital photography reduces costs and acquisition/processing time from earlier “tried and true” analog photography. This facilitates, advances, and compliments the efficacy of data collection for population and behavioral ecology studies on marine mammals, most recently allowing capture of individual identification images at distances of up to 2 km away.

DDG P Atlantic Aug 2016

DDG Q Atlantic Aug 2017

CG C Atlantic Aug 2014

Here we update U.S. West Coast Biologically Important Areas (BIAs) that were published in 2015 using new data and approaches. Additionally, BIAs were delineated for two species that were not delineated in the 2015 BIAs: fin whales and Southern Resident killer whales (SRKW). While harbor porpoise BIAs remained the same, substantial changes were made for other species including identifying both larger overall areas (parent BIAs) and smaller core areas (child BIAs). For blue, fin, and humpback whales we identified, delineated, and scored BIAs using the overlap between the distribution and relative density from three data sources, leveraging the strengths and weaknesses of these approaches: 1) habitat density models based on Southwest Fisheries Science Center (SWFSC) line-transect data from systematic ship surveys conducted through 2018, 2) satellite tag data from deployments conducted by three research groups, and 3) sightings of feeding behavior from non-systematic effort mostly associated with small-boat surveys for photo-identification conducted by Cascadia Research Collective. While the previous BIAs were based solely on a more subjective assignment from only the small boat sightings, here we incorporate the other two data sources and use a more rigorous, quantitative approach to identify higher density areas and integrate the data types. This resulted in larger, better-supported, objective BIAs compared to the previous effort. Our methods are also more consistent with the delineation of BIAs in other regions. For SRKWs, the parent BIA was based on a modification of the Critical Habitat boundaries defined by the National Oceanographic and Atmospheric Administration (NOAA) and the Department of Fisheries and Oceans (DFO) Canada; a core BIA highlighting areas of intensified use was identified using both NOAA’s Critical Habitat and kernel density analyses of satellite tag data. Gray whale BIAs were re-evaluated for the migratory corridor of Eastern North Pacific gray whales, for Pacific Coast Feeding Group feeding areas, and for gray whales that feed regularly in Puget Sound.

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.

A protected species monitoring program was initiated in 2007 when the US Navy identified Onslow Bay, NC as a potential site for an Undersea Warfare Training Range. To estimate marine mammal density, distribution and seasonality, traditional visual line transect surveys from both aerial and vessel platforms have been augmented with passive acoustic monitoring techniques. In 2010, 20 aerial (10,939 km of trackline) and 14 vessel (958 km of trackline) survey days were completed. In order of decreasing frequency Tursiops truncatus, Stenella frontalis, Grampus griseus, Globicephala macrorhynchus, Delphinus delphis, and Balaenoptera physalus were sighted. T. truncatus and S. frontalis comprised most sightings in both aerial (85%) and vessel (100%) surveys. Approximately 1,000 digital images were taken for species and individual identification during vessel‐based surveys. To date, six T. truncatus and one S. frontalis have been re‐sighted across seasons and years, suggesting some degree of residency in the study area. Passive acoustic monitoring techniques include towing a four‐element hydrophone array during vessel surveys and deploying High‐frequency Acoustic Recording Packages (HARPs) on the sea floor. Analysis of towed array recordings suggests that visual surveys detect approximately half of the dolphin groups that were acoustically detected. Hundreds of vocal detections are present in the HARP data, which will provide insights into of diel and seasonal patterns of marine mammal vocalization. This project, now in its fourth year, is providing a valuable long‐term window into abundance and residency patterns of cetaceans in offshore waters of North Carolina. 

Over 25 species of cetaceans utilize the shelf break regions of the US eastern seaboard, including several endangered species. Understanding patterns in species distribution, and the anthropogenic and environmental drivers that may impact their distribution, are critical for appropriate management of marine habitats. To better understand patterns in species distribution and vocal activity, NOAA’s Northeast Fisheries Science Center (NEFSC) and Scripps Institution of Oceanography (SIO) collaboratively deployed long-term high-frequency acoustic recording packages (HARPs) at eight sites along the western North Atlantic shelf break. This work was conducted from 2015-2021, with financial support from the Bureau of Ocean Energy Management (BOEM). Likewise, the U.S. Navy has been monitoring the shelf break region at 3 to 4 sites since 2007. Together these combined efforts bring the total to 11 recording sites spanning the U.S. eastern seaboard, from New England to Florida. This project focuses on analyses of the datasets collected from 2015-2021, with the inclusion of older (pre-2015) datasets where relevant. The focus of our efforts in 2025 have been to make substantial progress in the review of various detector classifications.

Passive acoustic monitoring was conducted within the Navy’s Cherry Point OPAREA during August – December 2011 and July – October 2012 for a total of 105 and 81 days respectively. This site is located approximately 100 miles from the North Carolina coastline on the shelf break. The 2011 deployment was at a water depth of 952 m and the 2012 deployment was at a water depth of 914 m. Acoustic data collected at this site provide information on the presence of marine mammals and anthropogenic sound sources. High-frequency Acoustic Recording Packages (HARPs) recorded sounds between 10 Hz and 100 kHz with recording cycles of 5 minutes every 10 minutes. The data were divided into three frequency bands and data were analyzed by scans of long-term spectral averages and spectrograms. Four baleen whale species were recorded: blue, fin, minke, and sei whales. The detections of their calls were made between late August and early December 2011. Blue whale calls were the only baleen whale call type detected in the 2012 deployment. No Bryde’s, humpback, or North Atlantic right whale calls were detected in either deployment. Several different toothed whale species were recorded: Blainville’s, Cuvier’s, and Gervais’ beaked whales, killer whales, pygmy or dwarf sperm whales (Kogia spp.), Risso’s dolphins, sperm whales, and unidentified odontocetes. All species except killer whales were recorded in 2011 and 2012. Killer whales were detected only in 2011. Ship noise was the most common anthropogenic sound in both deployments. MFA was noted during both deployments. A total of 391 pings were detected in 2011 with a maximum peak-to-peak received level of 156 dB re 1 μPa. In 2012, a total of 492 pings were detected with a maximum peak-to-peak received level of 167 dB re 1 μPa. Few echosounder pings over a variety of frequencies (4-80 kHz) were detected during both deployments. Explosions were detected in both deployments, though they were more prevalent in 2011 than 2012. High noise levels, possibly caused by instrument strumming and fluid flow at the sensor, occurred intermittently in both deployments and likely decreased the detection range for low-frequency sounds. This strumming was most prevalent in 2012.

The Rice’s whale (Balaenoptera ricei; formerly Gulf of Mexico Bryde's whale) is estimated to have a population size of 51 individuals in U.S. waters (Garrison et al., 2020), and was listed as endangered under the ESA in 2019 (84 Federal Register 15446, 87 Federal Register 8981). The majority of modern sightings occur within waters between the 100 and 400 meter isobaths within an area near the De Soto Canyon off northwestern Florida (Rosel et al., 2021; Soldevilla et al., 2017), an area defined as the Rice’s whale core distribution area (Rosel & Garrison, 2022). Occurrence patterns from long-term passive acoustic monitoring (PAM) over the 2010–2024 period and from summer and fall visual surveys during 2018 and 2019 indicate that the whales are found year-round within the core distribution area, but also suggest there may be seasonal movements throughout, and potentially out of, this area. High densities of anthropogenic activities occur throughout the Gulf of America (formerly Gulf of Mexico, hereafter GOA), including oil and gas exploration and extraction, fisheries, shipping, and military activities. Many of these activities, including U.S. Navy readiness activities, and Eglin Air Force Base activities, overlap with the whales’ core distribution area. Understanding seasonal distribution and density of Rice’s whales throughout this area will improve understanding of potential impact of human activities, improve the accuracy and precision of impact assessments, and assist in developing effective mitigation measures as needed. To improve management of human-based activities in the core distribution area of these endangered whales, the SEFSC deployed a sparse array of 17 PAM units concurrent with one long-term High-frequency Acoustic Recording Package (HARP) from May 2021 to March 2023. The PAM moorings were deployed in two lines of nine units each to nearly completely cover the core distribution area over a nearly 2-year period to improve understanding of seasonal and interannual distribution, movement patterns, and habitat use. The moorings used SoundTrap ST500 or ST600 STDs, calibrated long-term recorders capable of continuously recording underwater sound in the 20 Hertz to 48 kHz frequency range, including Rice’s whale calls and ambient noise, for up to 6 months. Additionally, the study leveraged a long-term HARP deployed by the SEFSC, Scripps Institution of Oceanography, and collaborators, at the De Soto Canyon site in the Rice’s whale core distribution area over the August 2020 to July 2025 period. At this site, they have continuously recorded ambient noise and other acoustic events in the 10 Hertz to 100 kHz frequency range since 2010 to monitor the impacts of the Deepwater Horizon oil spill and subsequent restoration activities on cetaceans. Analyses from the combined DC HARP and sparse array of SoundTrap deployments over the 2021-2023 period suggested Rice’s whale detections occurred at all PAM stations throughout the entire year, with detections occurring more commonly on the inshore line compared to the offshore line, and suggested call detections increased to the south in winter and to the north in summer. Additional data collection was recommended to determine whether these patterns were consistent over longer periods, as needed to understand seasonal distribution and density of Rice’s whales. To meet this need, a new 3-year project is being conducted from June 2025 to June 2028 that includes redeploying the PAM array for at least one more year, and conducting analyses of Rice’s whale spatiotemporal occurrence across the new (2025-2026) and historic (2021-2023) datasets. The project objectives include 1) characterizing spatiotemporal distribution of calling Rice’s whales throughout the CDA over three years to understand interannual variation in year-round occurrence patterns; 2) evaluating whether intra-annual habitat use patterns represent consistent seasonal cycles over time; and 3) evaluating longer-term trends in occurrence of calling Rice’s whales as needed for monitoring population recovery. Results from 2021-2023 will be combined with the current effort to yield the three full years of broad coverage passive acoustic data collection. The project is off to a successful start. In June 2025, 17 SoundTrap ST600 STD recorders were deployed at the same study sites from the 2021-2023 period, along with the De Soto Canyon HARP. In January 2026, all 17 SoundTrap recorders were successfully retrieved. Upon initial inspection, acoustic recordings from each instrument were of high quality, yielding a total of 3,524 instrument-days of recording effort. The instruments recorded for a median of 6.9 months each, with most recordings ending in late December or early January. All 17 SoundTrap recorders were serviced and redeployed for another 6-month deployment. They will be retrieved, along with the HARP, in June 2026. Data analyses, including Rice’s whale call detection, localization, and call density estimation will begin in fall 2026.

CG B HRC Feb 2014

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.

Nine Marine Autonomous Recording Units (MARU’s) were deployed in a rectangular array at a site coinciding with the United States (U.S.) Navy’s planned Undersea Warfare Training Range (USWTR) approximately 60150 km offshore Jacksonville, FL (13 September to 8 October and 3 December to 8 January, 2009–2010) at shallow, mid-depth, and deep sites (45, 183, 305 m). Data were reviewed in detail using TRITON (Wiggins, 2007). Event logs were created for each day at every site. Custom-written MATLAB scripts were used to calculate the probability of minke whale vocalization events occurring in the presence and in the absence of mid-frequency sonar. Minke whale vocalization events were completely absent in the fall deployment period, but occurred almost continuously during the winter deployment, indicating a strong seasonal pattern of occurrence. Minke whale vocalizations were detected most frequently at deep-water sites, and only at low levels (

Autonomous acoustic recorders are effective for investigating the distribution, occurrence, and acoustic behaviors of a variety of marine mammals in remote and deep-water locations. Nine Marine Autonomous Recording Units (MARU’s) were deployed in a rectangular array at a site coinciding with the United States (U.S.) Navy’s planned Undersea Warfare Training Range (USWTR) approximately 60-150 kilometers offshore Jacksonville, FL. All 9 units were deployed for 26 days in fall (13 September to 8 October) and 37 days in winter (3 December to 8 January) 2009-2010 at shallow, mid-depth, and deep sites (45, 183, 305 meters). The timing of the deployments allowed recordings of cetacean vocalizations and sonar activity to be made before, during, and after two U.S. Navy training exercises. The goal of this study was to characterize minke whale vocal activity in relation to U.S. Navy mid-frequency sonar signals. Data were reviewed in detail using the MATLAB program Triton (Wiggins 2007). Event logs were created for each day at every site. Custom-written MATLAB scripts were used to calculate the probability of minke whale vocalization events occurring in the presence and in the absence of mid-frequency sonar. Minke whale vocalization events were completely absent in the fall deployment period, but occurred almost continuously during the winter deployment, indicating a strong seasonal pattern of occurrence. Minke whale vocalizations were detected most frequently at deep-water sites, but only at low levels (

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).

This progress report summarizes offshore monitoring activities conducted between September 2024 and August 2025. The overarching objectives of the OCS remain focused on addressing key information gaps related to cetacean occurrence, exposure, and response within the conceptual framework for the U.S Navy Marine Species Monitoring Program.

DDG B Atlantic June 2010

CG A HRC Nov 2010

FFG-A Hawaii Range Complex FEB 2010

DDG A Atlantic March 2010

DDG D HRC Feb 2011

The U.S. Navy has proposed establishing an Undersea Warfare Training Range (USWTR) in an area between 60 and 150 km off the coast of Jacksonville, Florida. To establish baseline information on the occurrence and distribution of marine mammals in this area we conducted aerial and shipboard line-transect surveys and a passive acoustic monitoring program. Here we report the results of aerial and shipboard line-transect surveys conducted between January 2009 and April 2011. During this period, we flew 42,895 km of aerial tracklines and recorded 477 sightings of ten cetacean species (n=5,736 individuals). Tursiops truncatus was encountered most commonly (202 sightings, n=1,699), followed by Stenella frontalis (184 sightings, n=3,213). Other species observed during aerial surveys include Grampus griseus (n=350), Globicephala macrorhynchus (n=174), Steno acutorostrata (n=13), Eubalaena bredanensis (n=118),Balaenoptera glacialis (n=3), Physeter macrocephalus (n=2), Kogia spp. (n=1), and Megaptera novaeangliae (n=1). In 35 vessel surveys totaling 2,486 km we encountered three cetacean species in 77 sightings (n=576). S. frontalis and T. truncatus were observed most often, followed by G. griseus (n=351, 160, and 43, respectively). T. truncatus was observed throughout the entire survey area, but S. frontalis and S. bredanensis were seen exclusively on the continental shelf. All E. glacialis sightings, including a rare observation of an offshore birth, occurred on the western edge of the survey area. All other species were detected only in pelagic waters. Stenella frontalis, T. truncatus, and G. griseus were observed throughout the year (12, 11, and 9 calendar months, respectively); G. macrorhynchus and S. bredanensis were detected from April to October, and all mysticete species were seen only between December and March. This monitoring program, combining a variety of survey modalities, is providing a rich picture of the cetacean fauna in these poorly studied offshore waters.

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.

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. The sperm whale (Physeter macrocephalus) was the most frequently encountered whale, followed by Bryde’s and sei whales (Balaenoptera edeni and B. borealis, respectively). Occurrence of the sei whale is unique, because the species had not been confirmed to occur south of 20° N. The pantropical spotted dolphin (Stenella attenuata) was the most frequently sighted delphinid, followed by the striped dolphin (Stenella coeruleoalba) and false killer whale (Pseudorca crassidens). Humpback whales (Megaptera novaeangliae) were acoustically detected and later seen off Saipan. Numerous cetacean sightings were associated with steep bathymetric features including the West Mariana Ridge, the Mariana Ridge, and the Mariana Trench. Abundance estimates were based on 80 on-effort sightings for 12 species. Species were pooled into three separate groups for estimating detection probabilities: Balaenoptera spp., blackf ish (medium-size odontocetes), and small dolphins. A separate detection function was generated for the sperm whale. Precision of abundance estimates are very low for all species due to low sighting rates and high sea states; however, these abundance estimates serve as the best scientific data available for the area and establish vital baseline information for future research efforts.

DDG C SOCAL July 2010

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).

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.

A High-frequency Acoustic Recording Package (HARP; Wiggins and Hildebrand 2007) was deployed between March and October 2012 in the Cape Hatteras survey area at Site A in approximately 950 m. This HARP sampled continuously at 200 kHz and recorded for 28 days between 15 March 2012 and 11 April 2012. Long-Term Spectral Averages (LTSAs) were created for two frequency bands (10 Hz – 1000 Hz and 1 kHz – 100 kHz) and scanned for marine mammal vocalizations. Calls of fin whales, minke whales, beaked whales, Kogia spp., Risso’s dolphins, sperm whales, and unidentified delphinids were detected in the data.

A High-frequency Acoustic Recording Package (HARP; Wiggins and Hildebrand 2007) was deployed between May and November 2008 in Onslow Bay at Site B in 232 m. This HARP sampled at 200 kHz for 5 minutes of every 10 minutes and recorded for 103 days between 30 May 2008 and 10 September 2008. Long-Term Spectral Averages (LTSAs) were created for two frequency bands (10 Hz – 1000 Hz and 1 kHz – 100 kHz) and scanned for marine mammal vocalizations. Vocalizations of blue whales, Kogia spp., Risso’s dolphins, sperm whales, and unidentified delphinids were detected in the data.

A High-frequency Acoustic Recording Package (HARP; Wiggins and Hildebrand 2007) was deployed between July 2010 and February 2011 in Onslow Bay at Site D in 338 m. This HARP sampled at 200 kHz for 5 minutes of every 10 minutes and recorded for 210 days between 30 July 2010 and 24 February 2011. Long-Term Spectral Averages (LTSAs) were created for two frequency bands (10 Hz – 1000 Hz and 1 kHz – 100 kHz) and scanned for marine mammal vocalizations. Calls of blue whales, fin whales, minke whales, possible sei whales, Kogia spp., Risso’s dolphins, sperm whales, and unidentified odontocetes were detected in the data.

A High-frequency Acoustic Recording Package (HARP; Wiggins and Hildebrand 2007) was deployed between August 2011 and July 2012 in Onslow Bay at Site E in 952 m. This HARP sampled at 200 kHz for 5 minutes of every 10 minutes and recorded for 105 days between 19 August 2011 and 1 December 2011. Long-Term Spectral Averages (LTSAs) were created for three frequency bands (10 Hz – 1000 Hz, 500 Hz – 5000 Hz, and 1 kHz – 100 kHz) and scanned for marine mammal vocalizations. Calls of blue whales, fin whales, minke whales, possible sei whales, an unidentified beaked whale species, Blainville’s beaked whales, Cuvier’s beaked whales, Gervais’ beaked whales, killer whales, Kogia spp., Risso’s dolphins, sperm whales, and unidentified delphinids were detected in the data.

A High-frequency Acoustic Recording Package (HARP; Wiggins and Hildebrand 2007) was deployed between July and October 2012 in Onslow Bay at Site E in 914 m. This HARP sampled at 200 kHz for 5 minutes of every 10 minutes and recorded for 81 days between 14 July 2012 and 2 October 2012. Long-Term Spectral Averages (LTSAs) were created for three frequency bands (10 Hz – 1000 Hz, 500 Hz – 5000 Hz, and 1 kHz – 100 kHz) and scanned for marine mammal vocalizations. Calls of blue whales, Blainville’s beaked whales, Cuvier’s beaked whales, Gervais’ beaked whales, Kogia spp., Risso’s dolphins, sperm whales, and unidentified delphinids were detected in the data.

A High-frequency Acoustic Recording Package (HARP; Wiggins and Hildebrand 2007) was deployed between September 2009 and February 2010 in Jacksonville, FL, at Site A in 83 m. This HARP sampled at 200 kHz for 5 minutes of every 15 minutes and recorded for 91 days between 16 September 2009 and 15 December 2009, at which point the hydrophone was damaged possibly from an animal bite. Long-Term Spectral Averages (LTSAs) were created for three frequency bands (10 Hz – 1000 Hz, 500 Hz – 10 kHz, and 1 kHz – 100 kHz) and scanned for marine mammal vocalizations and mid-frequency active sonar. Vocalizations of minke whales, Risso’s dolphins, sperm whales, and unidentified delphinids were detected in the data.

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 Navy range complexes along the Atlantic coast. This program began in 2007, with baseline aerial and vessel surveys and a passive acoustic monitoring program in Onslow Bay, North Carolina and has since expanded to include study areas off Jacksonville, Florida and Cape Hatteras, North Carolina. In Onslow Bay, six years of monitoring have yielded a comprehensive picture of the density, distribution and abundance of marine mammals and sea turtles and provided new insights into residency patterns among pelagic delphinid cetaceans in this region. More than four years of monitoring in Jacksonville have provided similar information on the density and distribution of marine mammals and sea turtles in this area. In Cape Hatteras, almost three years of surveys have provided preliminary information on the complex patterns of distribution and diversity of the marine mammals and sea turtles in this highly productive area. The current report builds on this past body of work and describes passive acoustic monitoring activities that occurred at these three sites between January and December 2013.

A multi-institutional, marine protected species monitoring program, involving aerial, vessel and acoustic surveillance techniques, has been implemented at the proposed Undersea Warfare Training Range (USWTR) offshore of Jacksonville, Florida. This abstract reports on the second year of aerial and vessel visual line-transect and acoustic surveys used to investigate cetacean and sea turtle occurrence, distribution and abundance. During aerial surveys, a total of 269 track‐lines (22,695 km) were completed, the majority of which were flown in low Beaufort Sea State (BSS) conditions (94% in BSS 3 or lower). A total of 3,285 cetaceans were recorded in 286 sightings. Tursiops truncatus and Stenella frontalis were the most frequently encountered, followed by Grampus griseus, Globicephala macrorhynchus, Balaenoptera acutorostrata, Steno bredanensis, Eubalaena glacialis, Megaptera novaeangliae, and  Physeter macrocephalus. On March 20, an E. glacialis birth was observed, an event which has only been witnessed once before. Cetaceans were encountered 46 times during the 18.5 days of vessel surveys. Sightings consisted of S. frontalis, T. truncatus, G. macrorhynchus, and G. griseus. The towed passive acoustic array was deployed during 12 vessel surveys, generating a total of 13.75 hrs of recordings including all four sighted species. Two autonomous high frequency acoustic recording packages (HARPs) were deployed in the study region between March 1‐December 31 for long‐ term passive acoustic monitoring. HARP recordings have been recovered from the seafloor and are being analyzed for diel, seasonal, and interannual trends in cetacean occurrence. Surveys are scheduled to continue through 2012 to provide long‐term habitat usage patterns in the USWTR.

Bryde’s whales (Balaenoptera brydei/edeni) have been considered an anomalous occurrence in the Southern California Bight (SCB). Thus, they typically have been excluded from species lists associated with SCB management documents. In the last 40 years only two visual sightings of Bryde’s whales were documented in California waters, the last one in 1991 (Carretta et al. 2007). This is despite extensive systematic vessel and aerial surveys and presumed recent recordings of Bryde’s whale vocalizations in the SCB. Bryde’s whales are notoriously difficult to differentiate in the field and from fin (B. physalus) and sei whales (B. borealis), given the subtle differences in physical characteristics. Between August 2006 and September 2010, we photo-documented five sightings of five single Bryde’s whales in the SCB. Two of the five sightings occurred in October 2008 and September 2010 during 33,880 km of aerial surveys. The remaining three sightings occurred during small-vessel surveys that included offshore waters: two in June 2006 and one in September 2010. These sightings combined with other reports of presumed vocalizations suggest that Bryde’s whale numbers may be increasing in the SCB. This may be related to global warming, large-scale oceanographic events (e.g., El Niño and La Niña) and resulting changes in prey availability. However, no clear association pattern was evident between ENSO events and our sightings. The recent sightings reported herein indicate that the Bryde’s whale should be considered as a species present in the SCB and photodocumentation is critical to ascertain species.

Bryde's whales (Balaenoptera brydeij edem) have been considered an anomalous occurrence in the Southern California Bight (SCB). Thus, they typically have been excluded from species lists associated with SCB management documents. In the last 40 years only two visual sightings of Bryde's whales were documented in California waters, the last one in 1991 (Carretta et al. 2008). This is despite extensive systematic vessel and aerial surveys and presumed recent recordings of Bryde's whale vocalizations in the SCB. Bryde's whales are notoriously difficult to differentiate in the field, both from each other and also from fin (B. physa/us) and sei whales (B. borealis), given the subtle differences in physical characteristics. Between August 2006 and September 2010, we photo-documented five sightings of five single Bryde's whales in the SCB. Two of the five sightings occurred in October 2008 and September 2010 during 33,880 km of aerial surveys. The remaining three sightings occurred during small-vessel surveys that included offshore waters: two in June 2006 and one in September 2010. These sightings combined with other reports of presumed vocalizations suggest that Bryde's whale numbers may be increasing in the SCB. This may be related to global warming, large-scale oceanographic events (e.g., El Nino and La Nina) and resulting changes in prey availability. Recent sightings reported herein indicate that the Bryde's whale should be considered as a species present in the SCB and photo-documentation is critical to ascertain species.

Passive acoustic monitoring was conducted at a site in the US Navy’s Jacksonville Range Complex during 9 March – 26 August 2010. The site is located 50 nm east of the Florida coastline on the continental shelf. Acoustic data collected at this site provide information on the presence of marine mammals and naval sonar. High-frequency Acoustic Recording Packages (HARPs) recorded sounds between 10 Hz and 100 kHz with recording duty cycles of 5 minutes every 10 minutes. The data were divided into two frequency bands: (1) low frequencies, between 1 – 1000 Hz, and (2) mid frequencies, between 500 – 5000 Hz. These data were not analyzed for high frequency marine mammal sounds, such as the echolocation clicks of delphinids. Data were analyzed by scans of long-term spectral averages and spectrograms. High ambient noise levels, caused by instrument strumming and fluid flow at the sensor, were prevalent during this deployment and decreased detection ability for low-frequency sounds. Only one species of baleen whale—the humpback whale—was detected. Humpback non-song calls were detected during two days in March 2010. No blue whale, fin whale, Bryde’s whale, minke whale, North Atlantic right whale, or sei whale calls were detected in this deployment. Anthropogenic sound in the form of Mid-Frequency Active Sonar (MFA) was detected throughout this deployment. It was most common in late March 2010.

The U.S. Navy’s framework for marine mammal monitoring in the Gulf of Alaska will be presented. Regulatory permit drivers, ongoing monitoring and future monitoring through 2015 will be described. Ongoing monitoring in agreement with National Marine Fisheries Service (NMFS) includes deployment of two bottom-mounted highfrequency acoustic recording packages (HARP) from Scripps Institute of Oceanography. These devices were deployed on the shelf (200 m) and slope (1100 m) south of Seward, Alaska, in July of 2011. Data was recovered in May 2012, returned to Scripps for analysis, and the HARPs subsequently redeployed at the same locations for continued recording. Refinements in classification and analysis have benefited greatly from improvements identified from similar Navy-funded monitoring at other locations within the Pacific over the past eight years. A technical report on the Gulf of Alaska HARP analysis including species identification, seasonality, and identification of anthropogenic sounds will be presented by the Navy to NMFS in December 2013, and publically available by early 2013. New monitoring has also begun in 2012. A third Gulf of Alaska HARP was deployed offshore at Pratt Seamount (990 m) in September 2012. This HARP along with the previous two HARPs will have data retrieved in May 2013 for subsequent December 2013 reporting. In addition, the Navy is funding a vesselbased visual line transect survey within the Gulf of Alaska in the spring to summer 2013 time frame. This survey, similar to a Navy-funded one in 2009, will be conducted in association with NMFS to included visual transects, towed and sonobuoy passive acoustics, and where possible marine mammal biopsies and satellite tagging. Results from this survey should be available later in 2013.

The U.S. Navy represented by the Pacific Fleet Environmental Directorate, Chief of Naval Operations Environmental Readiness and Energy, Office of Naval Research, and Naval Postgraduate School, fund significant marine mammal monitoring programs within California. The bulk of this effort occurs within the Southern California Bight. In an endeavor coordinated with the U.S. National Marine Fisheries Service (NMFS) to address specific questions, efforts are underway to deploy a variety of research tools as a collection of focused, collaborative studies. Monitoring methods include research elements designed to collect data in support of region-specific monitoring and also contribute to the overall body of marine mammal knowledge. Research elements include visual surveys from airplanes and vessels, passive acoustic monitoring from bottom-mounted systems, photolD, biopsies, and marine mammal tagging. The framework for monitoring and results from August 2008 to August 2010 will be presented. During this period over 35,570 nautical miles of ocean were visually surveyed representing 2,285 hours of effort. There were 2,714 sightings of an estimated 155,375 marine mammals. Over 29,700 hours of passive acoustic recordings were obtained and are undergoing continued analysis. In addition, 24,000 digital photographs were taken of marine mammals, and 18 hours of digital video taken of various marine mammal behaviors. There were also 139 individual tissue biopsies, and 31 satellite tracking tags attached to various species. Continuing efforts in 2011 will employ many of the same techniques used previously. The Navy's annual monitoring reports for 2009 and 2010 are publically available and posted on NMFS' Office of Protected Resources website.

DDG U Atlantic Sept. 2019

DDG O Atlantic March 2016

DDG S Atlantic June 2018

CG D Atlantic March 2019

DDG M Atlantic April 2015

Bryde’s whales (Balaenoptera edeni) are commonly found in tropical and subtropical regions of the Pacific Ocean, but few studies have explored the presence of Bryde’s whales at the boundary of their distribution range. Such studies are increasingly relevant as climate impact models predict the range expansion of warm water species towards the poles in response to ocean warming. Like other baleen whales, Bryde’s whales produce distinct low frequency (o60 Hz) calls, which can be used for long-term acoustic monitoring of whale presence in an area. Autonomous passive acoustic recorders deployed at f ive sites in the Southern California Bight (SCB) were used to investigate the presence of Bryde’s whales in temperate waters from 2000 to 2010. Calling Bryde’s whales were observed in the SCB from summer to early winter, indicating a seasonal poleward range expansion. There was a significant increase in the presence of calling Bryde’s whales in the SCB between 2000 and 2010, but no significant correlation was found between Bryde’s whale presence and local sea surface temperature. Bryde’s whale occurrence is likely driven by prey availability within the California Current ecosystem, which is affected by seasonal and inter-annual changes in climate and oceanographic conditions. Continued monitoring of Bryde’s whales and their prey in the eastern North Pacific is needed to provide a longer time series and determine the full effect of climate variability and ocean warming on the distribution of this species.

Bryde’s whales (Balaenoptera edeni) are commonly found in tropical and subtropical regions of the Pacific Ocean, but few studies have explored the presence of Bryde’s whales at the boundary of their distribution range. Such studies are increasingly relevant as climate impact models predict the range expansion of warm water species towards the poles in response to ocean warming. Like other baleen whales, Bryde’s whales produce distinct low frequency (o60 Hz) calls, which can be used for long-term acoustic monitoring of whale presence in an area. Autonomous passive acoustic recorders deployed at f ive sites in the Southern California Bight (SCB) were used to investigate the presence of Bryde’s whales in temperate waters from 2000 to 2010. Calling Bryde’s whales were observed in the SCB from summer to early winter, indicating a seasonal poleward range expansion. There was a significant increase in the presence of calling Bryde’s whales in the SCB between 2000 and 2010, but no significant correlation was found between Bryde’s whale presence and local sea surface temperature. Bryde’s whale occurrence is likely driven by prey availability within the California Current ecosystem, which is affected by seasonal and inter-annual changes in climate and oceanographic conditions. Continued monitoring of Bryde’s whales and their prey in the eastern North Pacific is needed to provide a longer time series and determine the full effect of climate variability and ocean warming on the distribution of this species.

Climate impact models predict the range expansion of warm water species towards the poles in response to ocean warming. Bryde's whales (Ba/aenoptera edem) are commonly found in tropical and subtropical regions of the Pacific Ocean, but few studies have explored the presence of Bryde's whale at the boundaries of their distribution ranges. Like other baleen whales, Bryde's whales produce distinct low frequency (

During 2008 and 2009, we were able to passive acoustically monitor marine mammals in the presence of U.S. Navy anti-submarine warfare training exercises using mid-frequency tactical sonar. The exercises were conducted in the potential sites of the proposed east coast Undersea Warfare Training Range (USWTR). As part of the monitoring effort for these exercises, up to nine bottom-mounted passive acoustic recorders were deployed in Onslow Bay and Jacksonville USWTR sites. The recorders sampled continuously at 32 kHz and 2 kHz for approximate three weeks. We analyzed these acoustic recordings for marine mammal vocalizations and sonar activity using spectrogram correlation detector. The recordings contain hundreds of odontocete vocalizations, including pilot whales (Globicephala sp.) and sperm whales (Physeter macrocephalus), occurring before during and after the sonar events. A review of a subsample of the acoustic data revealed several instances of unidentified odontocetes apparently mimicking sonar signals with frequency modulated whistles of similar frequencies. Ongoing and future efforts will include deploying the recorders at the Jacksonville site in a tighter configuration and synchronizing them in time to localize vocalizations. This effort will provide insight on the proximity and movement of marine mammals in conjunction with Navy exercises occurring in area. These recorders yield important information about the presence and vocal activity of odontocetes during these naval exercises.

Passive acoustic data collected from Marine Autonomous Recording Units during fall (13 September to 8 October) and winter (3 December to 8 January) 2009-2010 were analyzed for acoustic detections of marine mammals and patterns resulting from these detections. The study site coincided with the United States (U.S.) Navy’s planned Undersea Warfare Training Range (USWTR) located approximately 60-150 kilometers off Jacksonville, Florida. Acoustic data consisted of both 2-kilohertz (kHz) and 32-kHz sample rate recordings. Data were initially reviewed using long-term spectral averages, and then evaluated in greater detail from spectrograms using the MATLAB program Triton (Wiggins 2007). Probability of vocalization event occurrence was calculated for each species relative to sonar events. Species and species groups detected included minke whale, North Atlantic right whale, sei whale, (probable) humpback whale, sperm whale, blackfish, and unidentified delphinids. Results indicated that minke whales were present almost continuously during the winter deployment period. Right whale vocalizations were most concentrated during winter, as expected, but were also detected at deep sites (>300 meters), which was somewhat unexpected. Sperm whales occurred exclusively near the continental shelf break, and showed a strong diel pattern with almost all vocalization events occurring between dawn and dusk. There were less obvious patterns for delphinid vocalization events, perhaps because of the grouping of species. Future efforts will include improving species-specific analysis of delphinids. Blackfish were detected relatively infrequently but were most common at the shallow-water sites. Minke whales showed the strongest relationship between sonar events and vocalizations. The probability of minke whale vocalization events occurring in the presence of sonar activity was much less than in the absence of sonar. The results reported here provide an assessment of marine mammal occurrence and distribution within the U.S. Navy’s planned USWTR and insights on species-specific vocal responses to sonar events.

September to 8 October) and winter (3 December to 8 January) 2009-2010. These data were analyzed for acoustic detections of marine mammals and navy sonar. Patterns of vocalizations, including seasonal and diel trends and effects of sonar activities were characterized. The study site coincided with the United States (U.S.) Navy’s planned Undersea Warfare Training Range (USWTR) located approximately 60‑150 kilometers off Jacksonville, Florida. The probability of vocalization events were calculated for each species relative to sonar events. Results indicated that minke whales were present almost continuously during the winter deployment period. Right whale vocalization events were most concentrated during winter, as expected, but also were detected at deep sites (>500m), which was somewhat unexpected. Sperm whale vocalization events occurred exclusively near the continental shelf break, and showed a strong diel pattern with almost all vocalization events occurring between dusk and dawn. There were less obvious patterns for delphinid vocalization events, possibly because we were not able to identify detections to species, and thus multiple species were grouped into one generic category. Blackfish were detected relatively infrequently but were most common at the shallow-water sites. Minke whales vocalization events had a strong negative relationship with sonar events when data from all sites were combined. These results provide an assessment of marine mammal occurrence and distribution within the U.S. Navy’s planned USWTR and important insights on species specific vocal responses, or lack of, to sonar events.

Evidence of seasonal use, foraging, and site fidelity from mark‐recapture efforts suggest the midAtlantic may provide important seasonal habitat for mysticetes (Swingle et al. 1993, Barco et al. 2002, Salisbury et al. 2015, Mallette et al. 2016).

The survey site includes an approximately 6,500-square-kilometer area off the coast of Virginia extending from the southern portion of the eastern shore of Virginia to the North Carolina/Virginia state border. The aerial survey design was established based upon advisements from the Centre for Research into Ecological and Environmental Modelling (CREEM) at the University of St. Andrews and objectives identified by the U.S. Navy

Eighteen years of visual survey and strandings data were used to describe baleen whale occurrence along the continental shelf of Virginia and North Carolina, U.S.A. This region experiences heavy anthropogenic use, which poses risks for mortality and injury to baleen whales. Between 2001 and 2019, six species of baleen whales were recorded, and whales occurred year-round. The total number of (on-and off-effort) sightings and strandings amounted to 838 whales, including humpback (Megaptera novaeangliae, n = 503), fin (Balaenoptera physalus, n = 197), North Atlantic right (Eubalaena glacialis, NARW, n = 76), common minke (B. acutorostrata, n = 51), sei (B. borealis, n = 10), and blue (B. musculus, n = 1) whales. Spatial modeling and abundance estimates indicated whale density and distribution changed seasonally. The highest densities of all whales combined occurred in winter and spring. Across seasons, average densities were highest in the northern portion of the study area. Ninety percent of NARW sightings were outside the designated Seasonal Management Areas in place for their protection. The stranding record offered a complementary view of species richness and seasonality. This study provides a baseline of baleen whale occurrence in an area experiencing increasing anthropogenic pressures (e.g., ship traffic and offshore wind-energy development).

This report documents Naval Information Warfare Center (NIWC) Pacific marine mammal monitoring efforts in fiscal year (FY) 2021 for Commander, Pacific Fleet (COMPACFLT) at the Pacific Missile Range Facility (PMRF), Kaua‘i, Hawai‘i.

This report documents Naval Information Warfare Center Pacific (NIWC Pacific) marine mammal monitoring efforts in fiscal year (FY) 2020 for Commander, Pacific Fleet (COMPACFLT) at the Pacific Missile Range Facility (PMRF), Kauai, Hawaii.

This report documents Naval Information Warfare Center Pacific (NIWC Pacific) marine mammal monitoring efforts in fiscal year (FY) 2019 for Commander, Pacific Fleet (COMPACFLT) at the Pacific Missile Range Facility (PMRF), Kauai, Hawaii.

This report documents Space and Naval Warfare Systems Center Pacific marine mammal monitoring efforts in FY18 for COMPACFLT at PMRF in Kauai, Hawaii.

This report documents Space and Naval Warfare Systems Center Pacific (SSC Pacific) marine mammal monitoring efforts in FY17 for Commander, Pacific Fleet (COMPACFLT) at the Pacific Missile Range Facility (PMRF), Kauai, Hawaii.

This report documents Space and Naval Warfare Systems Center Pacific (SSC Pacific) marine mammal monitoring efforts in FY15 for COMPACFLT at the Pacific Missile Range Facility (PMRF), Kauai, Hawaii, including during U.S. Navy mid-frequency active sonar (MFAS) training.

This report documents the Naval Information Warfare Center (NIWC) Pacific Whale Acoustic Reconnaissance Project (WARP) Laboratory’s marine mammal monitoring efforts in fiscal year (FY) 2024 for Commander, Pacific Fleet (COMPACFLT) at the Pacific Missile Range Facility (PMRF), Kaua‘i, Hawai‘i.

Opportunistic behavioral responses of baleen whales to disturbances from US Navy mid-frequency active sonar (MFAS) training at the Pacific Missile Range Facility, Kauai, Hawai’i, are being studied utilizing passive acoustic recordings. Automated passive acoustic detection, classification, localization, and tracking analyses of the data have shown a behavioral response in terms of a reduction, or cessation, of minke whale “boing” calling in response to US Navy training during the month of February 2011, 2012, and 2013 over a study area of 3,780 km2. The reduced calling is expressed as reduced minimum densities in the study area by utilizing acoustically localized individual whale counts. In February 2011, the density before sonar training was 3.64 whales while the density during sonar training was 0.69 whales (95% confidence intervals of 3.31-4.01 and 0.27- 1.8 whales, respectively). Individual ship-whale encounters have been observed to show cessation of calling from ship approaches without MFAS activity as well as ship approaches with MFAS. Sound Pressure Levels and Cumulative Sound Exposure Levels animals are exposed to are being estimated for evaluation of dose-response relationships. Tracking individual whales allows investigation of kinematics coupled with acoustic call details to establish baseline behaviors for comparison with observations during US Navy training.

Passive acoustic monitoring automated processes for detection, classification, model-based localization and tracking have been utilized for multiple species of baleen whales using recorded data from 47 off-shore, bottom-mounted broadband hydrophones at the Pacific Missile Range Facility, Kauai, Hawaii. Automatically detected baleen whales calls’ start times are compared with model-based localizations start times for determining locations where calls were emitted. Kinematic tracks are generated from localizations when multiple parameters exceed thresholds. The kinematic tracks support the notion of a single individual being tracked when call types, intervals, swim speeds and behaviors match what is known for a species. Localization and tracking capabilities increase knowledge of the species monitored by providing: density estimates based upon counts of animals which call, which are more informative than density of calls, directly measured cue rates of animals which call, species utilization of the various habitats being monitored, and different behavioral states of animals can be inferred. Information derived from kinematic tracks such as swim speeds and animal headings lead to basic behavioral observations such as ‘traveling’ (animals moving through the area at fairly constant headings and speeds) and ‘milling’ (where animals remain in the area for long periods of time with many heading and speed changes). Examples are provided for rarely sighted, but acoustically localized and tracked, minke (Balaenoptera acutorostrata) and Bryde’s (Balaenoptera brydei) whales. Behavioral responses of localized minke whales to Navy training have shown lower densities of calling animals in the area during Navy training compared to other periods of time.

OSU conducted a 4-year (2014–2017) tagging and tracking study on eastern North Pacific blue whales and fin whales to determine their movement patterns, occurrence, and residence times within U.S. Navy training and testing areas, as well as NMFS-identified BIAs. Tracking periods ranged from 0.6 to 283.8 d. Blue whale locations ranged from the northern tip of Vancouver Island, British Columbia, to very close to the equator, while fin whales were from Haida Gwaii, British Columbia, to the northern coast of Baja California, Mexico.

This report details the results of three years (2014-2016) of tracking data for blue and fin whales (Balaenoptera musculus and B. physalus, respecitvely) tagged in southern California waters, as well as one season of tracking data for humpback whales (Megaptera novaeangliae) tagged off the Oregon coast. T

In 2015 Oregon State University’s Marine Mammal Institute (OSU/MMI) conducted a second year of tagging operations in support of the United States (U.S.) Navy’s marine mammal studies in the offshore waters of the Southern California Range Complex (SOCAL) portion of the Hawaii-Southern California Training and Testing Study Area as well as the existing Northwest Training Range Complex (NWTRC), Naval Undersea Warfare Center Keyport Range Complex (together known as the Northwest Training and Testing Study Area). The focus of these studies is to address key science objectives the Navy has committed to complete as part of regulatory requirements promulgated from the National Marine Fisheries Service.

A 2-year tagging and tracking study was conducted on eastern North Pacific blue whales (Balaenoptera musculus) and fin whales (Balaenoptera physalus) to determine their movement patterns, occurrence, and residence times within Navy training and testing areas along the U.S. West Coast.

Twenty-four blue whales [20 location-only tags, 4 Advanced Dive Behavior (ADB) tags] and six fin whales (3 locationonly tags, 3 ADB tags) were tagged in August 2014 between Mugu Canyon, west of Malibu, and San Diego. CA .There was a great deal of individual variation in the tracks of both blue and fin whales, with blue whale locations extending from the northern tip of Vancouver Island in British Columbia to the Costa Rica Dome area off Central America, and those of fin whales extending from southern Oregon to central Baja California

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 Navy range complexes along the Atlantic coast. This program began in 2007, with baseline aerial and vessel surveys and a passive acoustic monitoring program in Onslow Bay, North Carolina and has since expanded to include study areas off Jacksonville, Florida and Cape Hatteras, North Carolina. In Onslow Bay, six years of monitoring have yielded a comprehensive picture of the density, distribution and abundance of marine mammals and sea turtles and provided new insights into residency patterns among pelagic delphinid cetaceans in this region. More than four years of monitoring in Jacksonville have provided similar information on the density and distribution of marine mammals and sea turtles in this area. In Cape Hatteras, almost three years of surveys have provided preliminary information on the complex patterns of distribution and diversity of the marine mammals and sea turtles in this highly productive area. The current report builds on this past body of work and describes monitoring activities that occurred between January and December 2013.

From June 2007 to April 2011, dedicated aerial and vessel surveys were conducted in a 1,713 km² area in Onslow Bay, NC, identified as a site alternative for a US Naval sonar training range. The site straddles the shelf-break and incorporates shallow, shelf and deeper, pelagic waters. The surveys were designed to investigate occurrence, density, and distribution of protected marine species. Sixty-seven complete aerial surveys covering 48,674 km, and 67 single track-line vessel surveys covering 5,642 km, were conducted. Tursiops truncatus, the most frequently encountered species, was recorded during every calendar month and observed throughout the range. This species displayed two distinct color patterns; dolphins east of the continental shelf break exhibited a white peduncle and were sighted in larger groups, while animals on the shelf were more uniform in color and were sighted in smaller groups. Stenella frontalis, the second most commonly encountered species, was sighted in 10 of 12 calendar months, and had a distribution restricted to inshore continental shelf waters. Globicephala macrorhynchus, Grampus griseus and Steno bredanensis occurred less frequently and were commonly encountered in summer. Only these five species were recorded during the first 33 months of effort. In the subsequent 14 months four additional species, Delphinus delphis, Balaenoptera physalus, Balaenoptera acutorostrata and Megaptera novaeangliae were observed in winter and spring months. The appearance of two “colder” water species, D. delphis and B. physalus, on the same day raises questions about oceanographic features that influence conditions inside the survey area. Variation in Gulf Stream position, and the presence of warm and/or cold core eddies, likely influences cetacean presence at this site in winter months. On-going efforts will be aimed at establishing the relationship between cetacean occurrence and local oceanographic conditions within this site

In 2008-2012, fifteen aerial surveys of systematic line-transects were conducted in the Southern California Bight to monitor and obtain baseline data on occurrence, distribution, density, abundance and behavior of marine mammals. Site characteristics at marine mammal locations were analyzed by estimating Resource Selection Functions (RSF) which quantified and described baseline habitat use as a precursor to assessing potential changes in these patterns relative to anthropogenic activities, including Navy exercises. For RSF analyses, characteristics at marine mammal locations were contrasted to characteristics at 35,167 randomly selected “available” locations in the study area. RSFs were estimated via the use-availability approach and predicted probability of species occurrence at all locations in the study area as a function of seven covariate habitat variables. Models for five species (n= 60 fin and 40 gray whale groups, 135 Risso’s and 31 bottlenose dolphin groups, 157 California sea lion groups) were fit for three behavior states (mill, rest/slow travel, medium/fast travel) and all behavior combined to document behavior and habitat associations. Species differed in habitat use and corresponding habitat associations. For example, medium-fast traveling fin whales were significantly associated with deep water over relatively flat basins/plateaus (p=0.0017). Fin whales also had significantly higher probability of using the San Nicolas Basin (p=0.0517). For Risso’s dolphins, rest/slow travel was associated with deeper water (i.e., steep ridges) (p=0.0803). These patterns suggest fast movement across basins and rest/slow travel over ridges. The RSF approach has been successfully implemented for terrestrial systems, quantitatively documenting changes in habitat-use patterns in response to human activities. Results herein illustrate successful application of RSF to pelagic marine mammals, quantitatively considering the role of behavior in habitat selection. Data provide an important 5-year baseline for little-known species to compare potential future changes in habitat selection patterns, assisting in conservation/management decisions in a relatively high anthropogenic use area.