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.

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.

Two Slocum gliders equipped with digital acoustic monitoring (DMON) instruments were deployed and operated in the mid-Atlantic Bight to the north and south of Cape Hatteras during the winter of 2018-2019. The gliders were remotely piloted to survey along pre-determined transects as local currents allowed, and sensor data were relayed to shore every 2 hours and posted on a publicly accessible website, dcs.whoi.edu. DMON data were reviewed daily by trained NAVFAC personnel, and the results of their review were posted on the same website, distributed to interested parties by text and email message, and made available for display in the Whale Alert app. Of the four baleen whale species monitored, humpback whales were the most commonly encountered, followed by fin, sei, and right whales. Only a single bout of right whale calls was detected by the glider deployed to the north of Cape Hatteras.

The U.S. Navy’s Atlantic Fleet conducts training and testing activities within the Northwest Atlantic Ocean and Gulf of Mexico, including the use of active sonar and explosives. In order to evaluate the impacts of these activities on marine mammals and other protected marine species, the Navy implemented a monitoring program to collect data on baseline animal presence, as well as exposure and response to Navy training and testing activities. Passive acoustic monitoring is an important component of the Navy’s monitoring efforts. Between 2009 and 2013, the Navy utilized effort-based monitoring metrics and targeted a number of different training and testing events for monitoring. Passive acoustic data was collected to monitor mysticete migration patterns in the mid-Atlantic, the effects of MFAS on odontocete vocalizations in North Carolina and Florida, and the potential effects of explosive training events off the coast of Virginia Beach, VA. Platforms included Marine Autonomous Recording Units (MARUs), High Frequency Acoustic Recording Packages (HARPs), Ecological Acoustic Recorders (EARs), and sonobuoys, among others. Additionally, the Marine Species Monitoring Program has funded the deployment of acoustic recording tags on several marine species including pilot whales and North Atlantic right whales, as well as behavioral response playback experiments with short-finned pilot whales off Cape Hatteras, North Carolina. In November 2013, the Navy began replacing effort-based monitoring metrics with objective based monitoring projects as a result of new environmental permits for Atlantic Fleet Training & Testing (AFTT). Passive acoustic monitoring remains a cornerstone of the revised long term goals, and continues to provide key data on marine mammal presence and behavior. Future work will focus on species classification and animal behavior.

In order to further investigate potential changes in behavior in response to MFAS exposure, sounds of marine mammals were recorded in the vicinity of three U.S. Navy training exercises before, during, and after the use of MFAS in Onslow Bay, North Carolina (July 2008), and near Jacksonville, Florida (September–October, and December 2009). The resulting passive acoustic data were analyzed using automated signal-detection software to detect individual sonar transmissions (“pings”), and sounds of North Atlantic right, minke, fin, and sperm whales. In addition, putative right whale “gunshot” sounds that had been detected in an earlier, separate analysis of the Jacksonville recordings were reviewed by two experienced marine mammal acoustic analysts.

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)

To monitor for the presence of marine mammals, High-frequency Acoustic Recording Packages (HARPs) were deployed at two sites within the Navy’s Virginia Capes Range Complex. There were three deployments at one site, located offshore from Cape Hatteras (HAT), between October 2012 and December 2014. There was one deployment at the other site, located offshore from Norfolk Canyon (NFC), between June 2014 and April 2015. Both sites were located approximately 75 nmi offshore in about 1000 m of water.

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

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

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.

The observations of this parturition event, along with the data presented by Patrician et al. (2009), and sightings of newly identified NARW neonates in waters off North Carolina and South Carolina (Waring et al. 2009), demonstrate that some rightwhalesgivebirthoutsidetheSEUSRightWhaleCriticalHabitat.Thisbirthing event also occurred offshore of the recently established SEUS Seasonal Management Area (U. S. Federal Register 2008) and in a region that has not before been the focus of systematic surveys. The observation of the birth of a NARW offers interesting biological insights into this critically endangered whale, but also identifies the need to investigate appropriate critical habitats and associated management areas vital to the continued recovery of this species.

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.

Passive acoustic monitoring was conducted using High-frequency Acoustic Recording Packages (HARPs) deployed in waters offshore of Virginia, North Carolina, and Florida with support from the US Navy during 2016 - 2017. The HARPs recorded underwater sounds between 10 Hz and 100 kHz. 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) Lowfrequency, between 10-1000 Hz, (2) Mid-frequency, between 1,000-5,000 Hz, and (3) Highfrequency, between 1-100 kHz.

A High-frequency Acoustic Recording Package (HARP; Wiggins and Hildebrand 2007) was deployed between July 2010 and June 2011 in Onslow Bay at Site A in 171 m. This HARP sampled at 200 kHz for 5 minutes of every 10 minutes and recorded for 216 days between 30 July 2010 and 3 March 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, North Atlantic right whales, possible sei 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 2014 and April 2015 in the Cape Hatteras, NC, survey area at Site A in 850 m. This HARP sampled continuously at 200 kHz and recorded for 217 days between 9 May 2014 and 11 December 2014. The data were divided into three frequency bands (10 Hz – 1000 Hz, 500 Hz – 5000 Hz, and 1 kHz – 100 kHz) and scanned for marine mammal vocalizations using Long-Term Spectral Averages (LTSAs) and automated detectors. Vocalizations of blue whales, fin whales, minke whales, sei whales, North Atlantic right whales, humpback whales, Kogia spp., Risso’s dolphins, sperm whales, Cuvier’s beaked whales, Gervais’ beaked whales, Blainville’s beaked whales, and unidentified delphinids were detected in the data.

A High-frequency Acoustic Recording Package (HARP; Wiggins and Hildebrand 2007) was deployed between May 2013 and March 2014 in the Cape Hatteras, NC, survey area at Site A in 970 m. This HARP sampled continuously at 200 kHz and recorded for 290 days between 29 May 2013 and 15 March 2014. The data were divided into three frequency bands (10 Hz – 1000 Hz, 500 Hz – 5000 Hz, and 1 kHz – 100 kHz) and scanned for marine mammal vocalizations using Long-Term Spectral Averages (LTSAs) and automated detectors. Vocalizations of blue whales, fin whales, minke whales, sei whales, North Atlantic right whales, humpback whales, Kogia spp., Risso’s dolphins, sperm whales, Cuvier’s beaked whales, Gervais’ beaked whales, Blainville’s beaked whales, possible Sowerby’s beaked whales, and unidentified delphinids were detected in the data.

A High-frequency Acoustic Recording Package (HARP; Wiggins and Hildebrand 2007) was deployed between October 2012 and May 2013 in the Cape Hatteras, NC, survey area at Site A in 970 m. This HARP sampled continuously at 200 kHz and recorded for 212 days between 9 October 2012 and 9 May 2013. The data were divided into three frequency bands (10 Hz – 1000 Hz, 500 Hz – 5000 Hz, and 1 kHz – 100 kHz) and scanned for marine mammal vocalizations using Long-Term Spectral Averages (LTSAs) and automated detectors. Vocalizations of blue whales, fin whales, minke whales, sei whales, North Atlantic right whales, humpback whales, Kogia spp., Risso’s dolphins, sperm whales, Cuvier’s beaked whales, Gervais’ beaked whales, Blainville’s beaked whales, and unidentified delphinids were detected in the data.

The primary objectives of the passive acoustic 26 monitoring program are to: 1) Determine the patterns of occurrence at each monitoring site; 2) Compare patterns of occurrence to better understand distributional patterns; and 3) Document species-specific characteristics of the vocalizations of marine mammal species 30 in each area.

Ten bottom-mounted passive acoustic recorders have been deployed off the coast of Virginia beginning in July 2015 and was maintained for two years. A combination of high-frequency Autonomous Multichannel Acoustic Recorders (AMARs), and low-frequency Marine Autonomous Recording Units (MARUs) was deployed in two spatial configurations (Figure 1), with the AMARs in a linear array extending east from the mouth of the Chesapeake Bay across the continental shelf and MARUs deployed as a synchronized localization array within the WEA.

Ten bottom mounted passive acoustic recorders are deployed off the coast of Virginia and will be maintained for two years. A combination of high-frequency Autonomous Multichannel Acoustic Recorders (AMAR), and low-frequency Marine Autonomous Recording Units (MARU) was deployed in two spatial configurations with the AMARs in a linear array extending east from the mouth of the Chesapeake Bay across the continental shelf, and MARUs deployed as a synchronized localization array within the WEA.

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

Passive acoustic monitoring is a powerful tool that allows remote detection of marine mammals through their vocalizations. While call detection provides information on species presence, additional information may be contained within the vocalizations that could provide more information regarding the demographics and/or number of individuals in a particular area based on passive acoustic detections. The North Atlantic right whale Eubalaena glacialis produces a stereotyped upswept call, termed the upcall, that is thought to function as a long-distance contact call in this species. As such, the call is likely to contain cues providing information about the individual producing it. The goal of this study was to test whether the right whale upcall could potentially encode information related to the identity and age of the caller. Using upcalls recorded from 14 known individuals through non-invasive suction cup archival acoustic tags, we demonstrate that the upcall does contain sufficient information to discriminate individual identity and age class, with average classification levels of 72.6 and 86.1%, respectively. Parameters measured from the fundamental frequency, duration, and formant structure were most important for discrimination among individuals. This study is the first step in demonstrating the feasibility of obtaining additional data from passive acoustic monitoring to aid in the conservation efforts for this highly endangered species.

According to the source-filter theory proposed for human speech, physical attributes of the mammalian vocal production mechanism combine independently to result in individually distinctive vocalizations. In the case of stereotyped calls with all individuals producing a similar frequency contour, formants resulting from the shape and size of the vocal tract may be more likely to contain individually distinctive information than the fundamental frequency resulting from the vibrating source. However, the formant structure resulting from such filtering has been historically undervalued in the majority of studies addressing individual distinctiveness in nonhuman species. The upcall of the North Atlantic right whale (Eubalaena glacialis) is characterized as a stereotyped contact call, and visual inspection of upcall spectrograms confirms presence of a robust formant structure. Here I present results testing age, sex, and individual distinctiveness of upcalls recorded from archival, suction cup mounted tags (Dtags). Multiple measurements were made using the fundamental frequency contour, formant structure, and amplitude of the upcalls. These three variable groupings were then tested alone and in combination with other groupings to assign upcalls to age classes based on reproductive maturity, age classes based on size, sex, and individual whales. To compare multiple classification methods, I used both discriminant function analysis and a classification and regression tree to classify calls to appropriate groups. In all analyses, the percentage of calls correctly assigned to the correct group—age, sex, individual—was significantly higher than chance levels. These results represent the first quantitative analysis of individual distinctiveness in mysticete whales and provide a baseline for further development of acoustic detection techniques that could be used to noninvasively track movements of whales across multiple habitats.

In response to permit requirements, the Navy has funded a series of surveys to be conducted off the US Atlantic coast to monitor protected species distribution. One of these survey efforts off Jacksonville, Florida, has recently finished three years of effort. The surveys have been conducted on a monthly basis year round since 2009 and include aerial, vessel and acoustic monitoring. Surveys will continue at the JAX site on a regular monthly basis. There have also been protected species monitoring surveys of a site off Onslow Bay, North Carolina, which were expanded in 2011, the protected species monitoring surveys were expanded to include a large region off the Outer Banks of North Carolina. These surveys are designed to assess seasonal distribution of marine mammals, specifically deep diving pilot and beaked whales off the continental shelf break. All visual monitoring sightings have been loaded onto the OBIS SEAMAP website and can be found at http://seamap.env.duke.edu/ . Enter a species or location of interest when in the website to see plots of sighting locations. Or, if specifically interested in the Jacksonville surveys, you can go to the ―Browse Datasets‖ tab and draw down to University of North Carolina Wilmington and view the USWTR JAX data sets.

Aerial and vessel surveys continue on a monthly basis at the proposed Undersea Warfare Training Range (USWTR) off the coast of Jacksonville, Florida. As of 20 May 2010, a total of 296 tracklines have been surveyed since January 2009, 131 of which were flown since January 2010 (Table 2). Since commencing vessel surveys in July 2009, a total of 17 surveys have been conducted, with six occurring in 2010. Two High-frequency Acoustic Recording Packages (HARPs) were recovered and downloaded this January. Both units were refurbished and are currently deployed. Right whales (Eubalaena glacialis) have been observed in or near the JAX USWTR survey area three times since starting surveys in 2009 (Table 3). On 20 March 2010, a single, large right whale was sighted at 10:20 at the western end of a trackline. The whale was observed for 27 minutes prior to the birth of a neonate. The neonate appeared at the surface after the adult had remained submerged, out of view, for several minutes. The aerial survey team continued observations for approximately 19 minutes before leaving the site and returning to land. At this point, the Florida Fish and Wildlife Conservation Commission aerial survey team moved in to continue documentation. Using photos taken by the two aerial survey teams, the New England Aquarium later confirmed the female whale as “Derecha,” #2360 in the North Atlantic Right Whale Catalog. The sighting of the birth is notable because it occurred outside existing critical right whale habitat, because of its proximity to the proposed USWTR site, and because it was only the second North Atlantic right whale birth observed (the other reported by Zani et al. Aquatic Mammals 2008 34(1): 21-24). The sighting is currently being prepared for publication. In addition to the witnessed birth, a lone male right whale (# 2303) was observed and photographed on 20 March at the western end of a trackline. On 2 April 2010, a right whale cowcalf pair was encountered during off-effort transit out to the range, approximately 2 nm from the western edge of the survey tracklines. The mother was identified as right whale #3360. Other cetacean species observed from 1 January through 20 May 2010 include sperm whales (Physeter macrocephalus), minke whales (Balaenoptera acutorostrata), short-finned pilot whales (Globicephala macrorhynchus), Risso’s dolphins (Grampus griseus), bottlenose dolphins (Tursiops truncatus), and Atlantic spotted dolphins (Stenella frontalis). All marine mammal sightings have been posted to the OBIS SEAMAP website and can be searched by species for sighting date and location.

As part of the U.S. Navy’s Atlantic Fleet Testing and Training program, we are monitoring the occurrence, distribution and density of cetaceans at three offshore sites along the U.S. Atlantic coast. We are using an identical suite of survey methods (line transect surveys, photo-identification, biopsy sampling and passive acoustic monitoring) at each 500nm2 reference site. Surveys began in Onslow Bay, NC in 2007, Jacksonville, FL in 2009 and Cape Hatteras, NC in 2011. To date we have conducted 48674km, 60687km, and 14213km of aerial surveys with 6883km, 3403km and 2443km of vessel surveys and 1201 days, 1264 days and 28 days of High frequency Acoustic Recording Package (HARP) recordings at Onslow, Jacksonville and Cape Hatteras, respectively. In both Onslow and Jacksonville, the cetacean fauna is dominated by Tursiops truncatus, with densities of 0.034/km2 and 0.025/km2 respectively and Stenella frontalis, with densities of 0.027/km2 and 0.045/km2 respectively. S. frontalis was encountered exclusively over the continental shelf. Grampus griseus and Globicephala macrorhynchus were the most commonly encountered pelagic odontocetes at these two sites. Species richness is much greater at Cape Hatteras than at the two southern sites (with 18 species sighted at Cape Hatteras, 10 at Jacksonville and 9 at Onslow), with the inclusion of several boreal species during colder months and the common occurrence of several deep-diving odontocetes, including Physeter macrocephalus, Ziphius cavirostris and Mesoplodon spp. Mysticetes, including Balaenoptera acutorostrata, B. physalus, Eubalaena glacialis, and Megaptera novaeangliae, were encountered only during winter at all three sites. In addition, we have detected the calls of two species on bottom-mounted HARPS that were not observed during visual surveys, including B. musculus and likely B. borealis. We highlight the particularly high diversity of cetaceans at the Cape Hatteras shelf break and suggest that this is a hotspot of species richness in the North Atlantic.

As part of the U.S. Navy’s Atlantic Fleet Testing and Training program, we are monitoring the occurrence, distribution and density of cetaceans at three offshore sites along the U.S. Atlantic coast. We are using an identical suite of survey methods (line transect surveys, photoidentification, biopsy sampling and passive acoustic monitoring) at each 500nm2 reference site. Surveys began in Onslow Bay, NC in 2007, Jacksonville, FL in 2009 and Cape Hatteras, NC in 2011. To date we have conducted 48674km, 60687km, and 14213km of aerial surveys with 6883km, 3403km and 2443km of vessel surveys and 1201 days, 1264 days and 28 days of Highfrequency Acoustic Recording Package (HARP) recordings at Onslow, Jacksonville and Cape Hatteras, respectively

Survey effort continues at the proposed Undersea Warfare Training Range (USWTR) off the coast of Jacksonville, Florida. The aerial survey effort that began in January 2009 is designed to cover the 10 track lines on the site at least twice per month and extra effort has been made to conduct additional aerial surveys during the right whale calving season. Additionally, shoulder data were collected during November 2009 in the form of on-effort transit legs to and from the survey site. Once the EWS right whale surveys end, shoulder data will be collected again through May 2010. To date, 185 USWTR track lines (approximately 16,000 km or 8,600 nautical miles) have been flown. Vessel survey effort that began in July 2009 takes place on the same track lines. Prior to the start of the right whale calving season a protocol was adopted for the research vessel when operating in right whale habitat. The vessel slows to 12 knots and posts watches while underway during daylight. Through January 2010, 14 vessel surveys have been conducted. A towed hydrophone array is deployed during vessel surveys to obtain simultaneous visual and acoustic data. Additionally, two High-frequency Acoustic Recording Packages (HARPs) are deployed at the USWTR site and are collected, downloaded and re-deployed every six months. No right whales have been sighted during any survey effort in the USWTR site. Right whales have been observed during vessel and aerial transits through the Right Whale Critical Habitat (RWCH). When right whales are observed from the plane during transit through the RWCH, observers note the location but the plane does not break track or descend from its agreed-upon 3000 ft. transit altitude. When encountered during vessel transits, location and ID photographs are obtained. Other species of marine mammals have been observed in the USWTR site including the minke whale (Balaenoptera acutorostrata), which was encountered during January and February 2009. Several odontocete species have been encountered during aerial and vessel surveys, with Atlantic spotted dolphins (Stenella frontalis) being the most commonly observed species, followed by bottlenose dolphins (Tursiops truncatus), Risso’s dolphins (Grampus griseus), rough-toothed dolphins (Steno bredanensis), and dwarf or pygmy sperm whale (Kogia sp.). In addition, short-finned pilot whales (Globicephala macrorhynchus) were encountered during off-effort transit through the USWTR survey area.

As described in the May 2009 RWN, part of the Navy’s USWTR program is a bio-monitoring program in the area of the proposed training range. The joint Duke University/UNC Wilmington USWTR JAX survey team is now housed in Fernandina Beach, Florida. Orion Aviation is contracted to provide Cessna 337 aircraft used for the aerial surveys. Vessel survey work is being conducted on the 38’ Duffy RV Two Angels that is contracted from Alex Loer. Aerial surveys have been conducted monthly (weather permitting) since January, with nineteen days of effort to date. Vessel surveys began in July and six days of effort have been undertaken thus far. Aerial and vessel survey effort is scheduled to be conducted monthly through at least the fall and winter. No right whales have been sighted on the USWTR trackline surveys to date.

Acoustic data collected from Marine Autonomous Recording Units during 26 days in fall (13 September to 8 October) and 37 days in 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 to 150 kilometers offshore Jacksonville, Florida

Passive acoustic data were collected from nine Marine Autonomous Recording Units (MARUs) deployed in a rectangular array 60-150 km off Jacksonville FL, USA. Units were deployed for 26 days during fall 2009, and 37 days in winter 2009-2010. The study area coincides with the U.S. Navy’s planned Undersea Warfare Training Range (USWTR). Data were manually reviewed using the MATLAB program Triton to create long-term spectral averages (LTSAs) and spectrograms, which were used to log marine mammal vocalization events, man-made noise and mid-frequency active sonar. Patterns and probabilities of vocalization events by species or species groups were characterized and related to sonar activities. Seasonal and diel patterns were qualitatively characterized. Vocalizations were detected for minke whales, North Atlantic right whales, sei whales, humpback whales, sperm whales, the blackfish group, and delphinids. Minke whale vocalization events occurred almost continuously during the winter deployment period but absent in fall. Right whale events occurred mostly during winter at shallow-water sites, but unexpectedly, also were detected at deep-water sites. Sperm whale events occurred exclusively near the continental shelf break, and exhibited a strong diel pattern with almost all vocalizations occurring between dusk and dawn. Less obvious patterns were apparent for delphinid events, probably because identification to the species level was not possible. Minke whale events had a strong negative relationship with sonar events when data from all sites were combined. These results provide an initial assessment of marine mammal occurrence and distribution within the U.S. Navy’s planned USWTR and provide important insights on the presence or absence of species-specific vocal responses to sonar events. Ongoing work includes using automated classification methods to identify delphinid whistles to species, and working with researchers at St. Andrews University to develop robust statistical approaches for analyzing the relationship between mid-frequency active sonar and vocal behaviors of marine mammals

Passive acoustic data were collected from nine Marine Autonomous Recording Units (MARUs) deployed 60–150 km in an area that coincides with the U.S. Navy’s planned Undersea Warfare Training Range (USWTR) off Jacksonville FL. MARUs were deployed for 26 days during fall 2009, and 37 days in winter 2009–2010. Data were manually reviewed for marine mammal vocalization events, man-made noise, and mid-frequency active sonar events, which were logged using TRITON software. Seasonal and diel patterns were characterized qualitatively. Patterns and probabilities of vocalization events by species, or species groups, were related to sonar events. Vocalizations were detected for minke whales, North Atlantic right whales, sei whales, humpback whales, sperm whales, the blackfish group, and delphinids. Minke whale pulse-trains occurred almost continuously during the winter deployment but were absent in fall. Right whale events occurred mostly during winter at shallow-water sites but unexpectedly were also detected at deep-water sites. Sperm whale events occurred exclusively near the continental shelf break and exhibited a strong diel pattern. Minke whale events had a strong negative relationship with sonar events. These results provide an initial assessment of marine mammal occurrence within the Navy’s planned USWTR and provide new information on vocalization events in relation to sonar.

We proposed a multi-year targeted tagging program to fill in these knowledge gaps, by collecting horizontal movement, dive profile, and vocal behavior from individual right whales using non-invasive suction cup tags (anticipated tag duration from 1-36 hours) including fastloc GPS technology, time depth recorders (TDR), 3-D movement measurements, and acoustic recordings. NMFS permits to conduct this research are held by Duke University with Dr. Nowacek as lead investigator and Dr. Parks as co-investigator. IACUC approval was obtained from both Duke University and Syracuse University IACUC committees prior to data collection.

Researchers proposed a targeted tagging program to fill in these knowledge gaps by collecting data on horizontal movement, dive profiles, and vocal behavior from individual right whales in February 2014. These objectives are accomplished using non-invasive suction cup tags (anticipated tag duration from 1 to 36 hours) that included Fastloc® Global Positioning System (GPS) technology, time-depth recorders, three-dimensional movement measurements, and acoustic recordings.

The primary objective of this targeted tagging program is to fill in these knowledge gaps by collecting data on horizontal movements, dive profiles, and vocal behavior from individual right whales. These objectives were accomplished using non-invasive suction-cup tags (anticipated tag duration from 1 to 36 hours) that included Fastloc® Global Positioning System technology, time-depth recorders, three-dimensional movement measurements, and acoustic recordings. National Marine Fisheries Service permits to conduct this research are held by Duke University with Dr. Nowacek as lead investigator and Dr. Parks as named co-investigator. Institutional Animal Care and Use Committee approval was obtained from Duke University and Syracuse University prior to data collection.

The primary objective of this targeted tagging program is to fill in these knowledge gaps by collecting data on horizontal movements, dive profiles, and vocal behavior from individual right whales through the use of non-invasive, suction-cup-attached, digital acoustic tags (DTAGs). In 2016, our expanded objectives included: (1) continuing to increase the sample size of extendedduration tag attachments, along with Fastloc® Global Positioning System (GPS) technology and (2) adding the capability for aerial photography using unmanned aircraft systems (UAS).

The primary objective of this targeted tagging program is to fill these knowledge gaps by collecting data on horizontal movements, dive profiles, and vocal behavior from individual right whales using non-invasive, suction-cup-attached, digital acoustic tags (DTAGs). In 2017, our expanded objectives included: (1) continuing to increase the sample size of extended-duration tag attachments, along with Fastloc® Global Positioning System (GPS) technology.

Right whales - range, numbers, conservation issues Southeast US - mother/calf pairs and juveniles in warm, shallow coastal waters • Ports of JAX and Brunswick • Naval Stations: Mayport and Kings Bay Motivation for the study - • need information to inform monitoring and mitigation of potential impacts of USWTR activities • focus on movement patterns and vocalization rates • proximity to USWTR • rates and types of vocalizations to inform PAM

Both the Mid-Atlantic Nearshore and Mid-Shelf Baleen Whale Monitoring Project and Offshore Cetacean Study aim to provide baseline occurrence and ecological information to the U.S. Navy regarding how marine mammals use the VACAPES OPAREA. These projects aim to answer questions regarding the baseline ecology, behavior, movement patterns, and site fidelity of marine mammals that may be exposed to U.S. Navy training and testing exercises. HDR Inc. researchers use a variety of vessel-based methodologies, including photo-identification (photo-ID), biopsy sampling, drones, satellite-linked telemetry tags, and digital archival tags (Digital Acoustic Recording Tags [DTAGs] and Customized Animal Tracking Solution [CATS] tags). DoN | Mid-Atlantic Marine Mammal Aerial Survey Effort: 2024/25 Annual Progress Report April 2026 | 2 To better assist the vessel team with these efforts and in locating target species, non-systematic aerial surveys were implemented beginning in March 2021 (Aschettino et al. 2023). Aerial survey efforts increased during the 2022/23 and 2023/24 seasons, with 8 (Aschettino et al. 2024b) and 13 (Ozog and Engelhaupt 2025) surveys flown, respectively. While surveys were primarily associated with locating NARWs, some aerial surveys were also flown in tandem with Offshore Cetacean Study field work. This report details the coverage and sightings from aerial surveys flown during the 2024/25 field season in coordination with vessel field work for both projects. See the individual project technical reports for more details on each (Aschettino et al. 2026, Engelhaupt et al. 2026).

North Atlantic right whales are an endangered species of baleen whale that migrates along the east coast of the United States, with winter calving grounds located in the coastal waters off Florida and Georgia. This study investigated the acoustic environment experienced by individual right whales swimming through this habitat though the use of suction cup attached acoustic recording tags. Nineteen tag attachments were made between 2014 and 2016. These tags documented a range of sounds from the right whale acoustic environment, including calls produced by the tagged whale, sounds produced by conspecifics, as well as sounds from other biological (fish and dolphin) and anthropogenic sources. The call rates of individual whales were relatively low, with calls typically produced in short duration bouts. Sounds from other biological sources, particularly fish and dolphin, and anthropogenic sources, particularly vessels, were common. This project presents an initial step toward characterizing the acoustic environment experienced by individual whales to allow future comparisons to stationary acoustic recordings in the same habitat.

Passive acoustic monitoring is a common method for detection of endangered North Atlantic right whales. This study reports on the acoustic behavior of right whales on the winter calving grounds to assess their acoustic detectability in this habitat. In addition to known call types, previously undescribed low amplitude short broadband signals were detected from lactating females with calves. The production of higher amplitude tonal calls occurred at lower rates for lactating females than from other age/sex classes suggesting that passive acoustic monitoring may be less effective in detecting mother-calf pairs in this critical habitat area.

In this study, we explore the potential for acoustic crypsis, a form of cryptic behaviour to avoid predator detection, in North Atlantic right whale mother-calf pairs. We predicted that mother-calf pairs would either show reduced calling rates, reduced call amplitude or a combination of these behavioural modifications when compared with other demographic groups in the same habitat. Our results show that right whale mother-calf pairs have a strong shift in repertoire usage, significantly reducing the number of higher amplitude, long-distance communication signals they produced when compared with juvenile and pregnant whales in the same habitat. These observations show that right whale mother-calf pairs rely upon acoustic crypsis, potentially to minimize the risk of acoustic eavesdropping by predators.

From 2007 to2013,acomprehensive acoustic monitoring effort was conducted within the boundaries of the Onslow Bay study area to study marine mammal presence and ambient noise levels. The objective was to characterize the vocalizations of marine mammal species in the area, identify their seasonal presence patterns, and assess the potential impacts of naval operations on these species. This report presents the findings from the analysis of data collected using High-frequency Acoustic Recording Packages (HARPs; (Wiggins & Hildebrand 2007)), which were strategically deployed within the Onslow Bay study area across a shelf-to-slope gradient.

The U.S. Navy’s Jacksonville Range Complex (JAX) is located in the South Atlantic Bight offshore northeastern Florida and southeastern Georgia. From 2009 to 2020, passive acoustic monitoring was conducted using High-frequency Acoustic Recording Packages (HARPs) deployed across a depth gradient spanning the continental shelf and slope. Three sites were located on the shallow shelf (A–C; approximately 40–90 m), and one site was located on the continental slope (D; approximately 730–800 m). These long-term acoustic data provide a comprehensive assessment of marine mammal occurrence and ambient sound conditions across the region.

From 2014 to2021, a comprehensive acoustic monitoring effort was conducted within the boundaries of the Virginia Capes Range Complex to study marine mammal presence and ambient noise levels. The objective was to characterize the vocalizations of marine mammal species in the area, identify their seasonal presence patterns, and assess the potential impacts of naval operations on these species. This report presents the findings from the analysis of data collected using six High-frequency Acoustic Recording Packages (HARPs; Wiggins & Hildebrand 2007), which were strategically deployed within the Virginia Capes Range Complex near Norfolk Canyon (Figure 1 & Table 1).

From 2012 to 2020, a comprehensive acoustic monitoring effort was conducted within the boundaries of the Virginia Capes Range Complex to study marine mammal presence and ambient noise levels. The objective was to characterize the vocalizations of marine mammal species in the area, identify their seasonal presence patterns, and assess the potential impacts of naval operations on these species. This report presents the findings from the analysis of data collected using 12 High-frequency Acoustic Recording Packages (HARPs; Wiggins & Hildebrand 2007), which were strategically deployed offshore from Cape Hatteras within the southern portion of the Virginia Capes Range Complex (Figure 1 & Table 1).

A High-Frequency Acoustic Recording Package (HARP) was deployed from April 2016 to June 2017 to detect marine mammal and anthropogenic sounds in the Navy’s Virginia Capes Range Complex offshore from Norfolk Canyon (NFC). The HARP was located 75 nm offshore in approximately 1000 m of water. The HARP recorded sound in the frequency band 10 Hz – 100 kHz. 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 10-500 Hz, (2) Mid-frequency, between 10-5,000 Hz, and (3) High-frequency, between 1- 100 kHz.

The Critically Endangered North Atlantic right whale Eubalaena glacialis entered a population decline around 2011. To save this species without closing the ocean to human activities requires detailed information about its intra-annual density patterns that can be used to assess and mitigate human-caused risks. Using 2.9 million km of visual line-transect survey effort from the US Atlantic and Canadian Maritimes conducted in 2003-2020 by 11 institutions, we modeled the absolute density (ind. km-2) of the species using spatial, temporal, and environmental covariates at a monthly time step.

This document represents a brief annual summary on work completed between January 1st, 2024 to December 15th, 2024, under award N66604-22-D-F200, which is part of a broad project to monitor the populations of goose-beaked whales (Ziphius cavirostris) and fin whales (Balaenoptera physalus) in the Southern California Testing and Training Range (SCTTR).

In fall 2013, Duke University and the National Oceanic and Atmospheric Administration Northeast Fisheries Science Center initiated a passive acoustic monitoring effort to detect North Atlantic right whales (Eubalaena glacialis) migrating past Cape Hatteras, North Carolina, during their seasonal movements to and from winter breeding grounds in Florida. The objectives of this project are to investigate the timing of right whale migration through the Mid-Atlantic region, as well as the relative distance from shore and acoustic behavior of migrating whales. This effort will help to fill a data gap in the central portion of the migratory corridor, and contribute to a broader understanding of the seasonal occurrence of right whales along the U.S. east coast. The project is ongoing, and this report details passive acoustic data collection and analysis between October 2013 and December 2014.

The objectives of this project are to investigate the timing of right whale migration through the Mid-Atlantic region, as well as the relative distance from shore and acoustic behavior of migrating whales. This effort will help to fill a data gap in the central portion of the migratory corridor, and contribute to a broader understanding of the seasonal occurrence of right whales along the U.S. east coast.

This report describes results from 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

Long-term high-frequency acoustic recording packages (HARPs) at eight sites along the western North Atlantic shelf break.

Long-term high-frequency acoustic recording packages (HARPs) at eight sites along the western North Atlantic shelf break.

This study aims to assess the co-occurrence of cetaceans and anthropogenic activities, presenting simple and accessible visualizations of the temporal and spectral overlap.