Rough-toothed dolphins (Steno bredanensis) are reported to form isolated communities with stable groups around some oceanic islands. Within these communities, this species exhibits cooperative foraging and care-giving behavior including the sharing of large prey. These group behaviors could be driving community level structure where there are clear differences in habitat use between island groups, and limited movement among islands. Similar social characteristics are found in other cetacean species, e.g. killer whales, where individuals remain in maternally related groups indefinitely, forming “extended matrilines” as reflected by a single mitochondrial (mt) DNA haplotype. Here we test the hypothesis that rough-toothed dolphins also form “extended matrilines” using mtDNA control region haplotypes as a marker for maternal lineages. Alternatively, we test the influence of maternal fidelity on group structure within communities. The sample collection comprises adults from Pacific Ocean Islands and the continental Atlantic USA spanning 1976-2010. We sequenced mtDNA from 4 deceased groups (3 mass strandings and 1 bycatch; 350bp; n=28 teeth samples) and 14 living groups (460bp; n=106 skin samples) identifying 22 haplotypes. Differentiation and haplotype diversity were evaluated for groups within island communities in the Hawaiian Islands (Kauai and Hawaii) and Society Islands (Moorea and Raiatea) as well as between islands communities. Our results revealed multiple matrilines in 16 of the 18 groups, allowing us to reject the hypothesis of strict matrilineal structure. Although an AMOVA detected significant differentiation between island communities, groups did not significantly partition any genetic diversity within island communities. This is consistent with permutation tests where no strong signal of matrilineal influence was identified within island communities. Our study provides evidence of genetic structure at the community level, but demonstrates negligible structure at the group level. Fine-scale analyses to evaluate kinship and temporal association patterns are underway to further our understanding of group structure for this species.

This report describes results from vessel surveys and visual species verifications conducted at the Jacksonville Shallow Water Training Range (JSWTR) in the Jacksonville Operating Area (OPAREA).

This report describes results of vessel surveys 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.

This report describes results from vessel surveys and visual species-verification trials conducted at the Jacksonville Shallow Water Training Range (JSWTR) in the Jacksonville Operating Area (OPAREA). This work continues from a multi-institutional monitoring program intended to provide information on the species composition, population identity, density, and baseline behavior of marine mammals and sea turtles present in United States (U.S.) Navy range complexes along the U.S. Atlantic Coast.

This proof-of-concept study was undertaken to establish whether wild seals could be successfully captured and tagged in coastal Virginia, because this has not been previously attempted in this area. Further, the study sought to establish the feasibility of using satellite tags to better understand seals’ residency time in Virginia waters, their local habitat utilization patterns, and where they migrate to in the spring. The information gathered from this effort will provide valuable baseline data needed for the future assessment of harbor seal movements and site fidelity along the U.S. Eastern Seaboard.

Since 2017, the Navy has undertaken telemetry (tagging) studies in order to characterize seals’ at-sea movements, habitat use, dive behavior, and the environmental variables that may influence their distribution and haul-out patterns. Location-only and depth-sensing tags, which track seals’ movements via satellite transmission, were deployed on seven harbor seals in 2018 and two in 2020 (no tags have been deployed to date on gray seals as part of this study).

Key results from the 2018 and 2020 tags, detailed methods and results from the 2022 tagging efforts, and where appropriate, cumulative analyses of all 14 satellite-tracked tags deployed to date.

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

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

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

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

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

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

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

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

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

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

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

The HDR Monitoring Team is tasked to initiate a monitoring project that will provide quantitative data and information on the seasonal occurrence, distribution, and density of protected species (marine mammals and sea turtles) in Chesapeake Bay waters near Naval Air Station (NAS) Patuxent (PAX) River, roughly from Drum Point, south to Smith Point along the western shore and over to the coastal waters of the eastern shore.

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

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

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

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

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

The purpose of this report is to summarize information obtained through the remote deployment of Low-Impact Minimally-Percutaneous External-electronics Transmitter (LIMPET) satellite tags on odontocete cetaceans off Cape Hatteras, North Carolina, in 2014. This study was undertaken to provide information on spatial use and diving behavior of a number of species of odontocetes, with particular emphasis on Cuvier’s beaked whales (Ziphius cavirostris) and short-finned pilot whales (Globicephala macrorhynchus).

The present work is intended to complement ongoing research by Duke University off Cape Hatteras (hereinafter referred to as the Duke program) by providing information on the movement and diving behavior of these species over the medium term (weeks to months). The Duke program is focusing on shorter-term dive behavior (i.e., hours to days) using Digital Acoustic Tags and longer-term movements (i.e., months to years) using photo-identification (photo-ID) techniques

. This report summarizes information obtained through additional field efforts undertaken in 2016, while incorporating results from the first two years of effort. The present work is intended to complement ongoing research by Duke University off Cape Hatteras (hereinafter referred to as the Duke program) by providing information on the movement and diving behavior of these species over the medium term (weeks to months)

This work builds upon and complements longer-term studies of movements and site fidelity of both Cuvier’s beaked whales (Ziphius cavirostris) and short-finned pilot whales (Globicephala macrorhynchus) off the North Carolina coast using photo-identification (photo-ID)

This work builds upon and complements longer-term studies of movements and site fidelity of both Cuvier’s beaked whales (Ziphius cavirostris) and short-finned pilot whales (Globicephala macrorhynchus) off the North Carolina coast using photo-identification (photo-ID)

The goals of this study were to determine abundance, habitat use, and distribution patterns of bottlenose dolphins in St. Andrew Bay and adjacent coastal waters in the NSWC PCD Testing Range over two seasons.

The goal of the spring 2016 component of this project was to conduct photographicidentification (photo-id) surveys to determine seasonal (spring) abundance, habitat use, and distribution patterns of bottlenose dolphins in St. Andrew Bay (SAB) and adjacent coastal waters surrounding the Naval Surface Warfare Center, Panama City Division (NSWC PCD).

The goal of the fall 2016 component of this project was to conduct photographic-identification (photo-id) surveys to determine seasonal (fall) abundance, habitat use, and distribution patterns of bottlenose dolphins in St. Andrew Bay and adjacent coastal waters surrounding the Naval Surface Warfare Center, Panama City Division (NSWC PCD).

The goals of this study were to conduct photographic-identification (photo-ID) surveys during 2015 and 2016 to determine abundance, distribution patterns, habitat use, and site fidelity of bottlenose dolphins in St. Andrew Bay and adjacent coastal waters in the NSWC PCD Testing Range over four sampling periods (July and October 2015, and April and October 2016).

The ultimate goal of this study is to provide the United States (U.S.) Navy with the necessary data to help identify seasonal areas where cheloniid sea turtles are likely to occur in order to inform U.S. Navy environmental planning efforts. This project focuses on the three cheloniid sea turtle species commonly seen in Virginia.

The goal of this report is to provide the United States (U.S.) Department of the Navy (Navy) with the necessary data to help identify seasonal areas where Kemp’s ridley and green turtles are likely to occur in order to inform Navy environmental planning efforts.

Five species of sea turtles occur in Chesapeake Bay and the coastal waters of Virginia with varying regularity. They include the loggerhead turtle (Caretta caretta), Kemp’s ridley turtle (Lepidochelys kempii), green turtle (Chelonia mydas), leatherback turtle (Dermochelys coriacea), and hawksbill turtle (Eretmochelys imbricata) (Musick and Limpus 1997). Loggerhead and Kemp’s ridley turtles are the most abundant and regularly occurring species, and green turtle numbers have increased over the past two decades in Virginia (Barco et al. 2015, Swingle et al. 2014, 2015, 2016).

The goal of the project is to assess the occurrence, habitat use, and behavior of loggerhead, green, and Kemp's ridley turtles in the Hampton Roads region to better assess the impacts that U.S. Navy activities may have on these protected species.

The ultimate goal of this study is to provide the US NAVY with the necessary data to help identify seasonal areas where cheloniid sea turtles are likely to occur in order to inform DOD sea turtle protection efforts. This project focuses on the three cheloniid sea turtle species commonly seen in Virginia, which are the loggerhead sea turtle, Kemp’s ridley sea turtle, and green sea turtle (Hager 2014).

Kemp’s Ridley Tagging and Tracking in Chesapeake Bay and Costal Waters of Virginia: Final Report

The Virginia Aquarium Foundation (VAQF) and the U.S. Navy have been working together since 2013 to determine the efficacy of using acoustic telemetry for investigating the fine scale movements of sea turtles in the vicinity of Navy facilities in southeastern Virginia. To date, we have deployed 56 acoustic tags (VEMCO V16, V13 and V9 69 kilohertz tags), 14 from Jul-Nov of 2013, 24 in 2014 and 18 May-Jul of 2015. The U.S. Navy maintains an array of 71 acoustic receivers (VEMCO VR2W) in southeastern Virginia and downloads and processes data every other month. There is a four to six month delay from the time of detection to VAQF receiving processed tag detection data. For this reason, we will discuss results for turtles tagged in 2013 and 2014. Of the 38 turtles tagged in 2013-14, five were wild caught (incidentally or directly captured) and 33 were stranded, rehabilitated and released. Of the stranded turtles, 14 were caught on recreational hook and line, 13 were cold-stunned and the rest were boat strikes (n=3), diseased (n=2) or entangled in other gear (n=1). In total we deployed tags on 18 loggerheads, 15 Kemp’s ridleys (one was released twice) and 4 green turtles. Of these 15 (83%) of the loggerheads were detected, 11 (73%) of the Kemp’s ridleys were detected and 3 (75%) of the greens were detected. Seven of the turtles stranded dead since release (3 wild and 4 stranded) and of these one was never detected. Seven turtles were released after mid-Oct south of the Navy receiver array and, of these, four were never detected. For loggerheads, Kemp’s and greens that were detected, mean number of detections were 220, 57, and 187, number of different days detected were 6, 3, and 10, and days post-release were 97, 21, and 53 respectively.

We conducted aerial surveys of sea turtles in 2011 and 2012, incorporating corrections for perception and availability bias in Chesapeake Bay and near-shore continental shelf waters of the Mid-Atlantic Bight off the US states of Virginia and Maryland. Results of these surveys and ancillary research to determine surface times for loggerhead turtles provide us with a new baseline population estimate for turtles in the region. Prior surveys were conducted in Chesapeake Bay in the mid-1980s and early 2000s, and in ocean waters in the late 1970s and early 1980s. Although comparison of density estimates not corrected for availability between prior surveys and this effort suggests that the population of sea turtles, especially loggerhead turtles, is higher than previous estimates, differences between surveys may be the result of survey methodologies and cannot be assumed to be true changes in density. Surface time for availability corrections was calculated using dive summaries from satellite telemetry on 27 loggerhead turtles tracked between 2011 and 2015. We calculated stratified seasonal availability corrections for bay and ocean waters based on assumed differences in turtle behavior and water clarity between the 2 habitats. For each habitat, we provided seasonal corrections for 3 detection depth bins (shallow, moderate, and deep) to account for differences in sub-surface detection ranges. Differences and trends toward differences among availability corrections underscore the need to better understand the many variables that affect surface time for sea turtles in temperate waters, and the effect that availability has on abundance and density estimates.

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.

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 mamma ls. 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, shore-based studies of bottlenose dolphins (Tursiops truncatus) in Galveston Bay, Texas (2011 - 2013), and gray whales (Eschrichtius robustus) off Sakhalin Island, Russia (2004 -2010).

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. While training and testing activities have the potential to impact the environment, the Navy employs every means available, without jeopardizing the safety of Sailors or impacting military readiness, to mitigate the potential environmental effects of these activities. Prior to training and testing activities, the Navy consults extensively with environmental regulators to determine appropriate mitigations to protect marine species, particularly marine mammals. Additionally, in order to evaluate the impacts of Navy activities on marine mammals and other protected species, the Navy has 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 remains a cornerstone of addressing revised long term objectives of the monitoring program, and continues to provide key data on marine mammal presence and behavior. Future work will focus on species classification and animal behavior before, during, and after exposure to potential stressors. This presentation will provide an overview of Navy environmental compliance in the Atlantic, including monitoring efforts. This presentation will also discuss the tools and processes that Navy uses to assess the potential impacts of activities, how mitigation is used to reduce those impacts, and protective measures such as the restrictions employed in the North Atlantic right whale critical habitat areas. The Navy remains committed to marine stewardship and responsible management of the potential impacts of training and testing activities on protected species.

DDG P Atlantic Aug 2016

DDG Q Atlantic Aug 2017

During a marine mammal vessel survey, a single Perimyotis subflavus (Tricolored Bat) was sighted 103.5 km off the coast of North Carolina. While we cannot determine whether the bat flew unaided from the mainland or stowed away on a ship, this is likely the furthest offshore sighting for the species. The possibility of Tricolored Bats flying offshore could have implications for wind-energy programs or other offshore industries.

CG C Atlantic Aug 2014

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.

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

Environmental stewardship is an integral part of the Navy's mission. It protects and preserves the capabilities of training areas, ensures operational flexibility, and sustains the resources and public support needed to carry out the Navy's mission. The Navy is responsible for compliance with a suite of environmental and natural resources laws and regulations that apply to the marine environment, and in particular, to sea turtles. To comply with these mandates, the Navy works closely with regulatory agencies and must be able to properly evaluate the impacts of at-sea training activities on protected species. In order to institute efforts to minimize these impacts there must be: I) the best available data on the density and distribution of the species in question; 2) the criteria necessary to assess impacts; and 3) the creation of the practical mitigation measures. To meet these objectives, the Navy developed the Navy Marine Species Density Database (NMSDD) which documents density estimates for all sea turtle populations where the Navy primarily trains in the Atlantic Ocean and Gulf of Mexico. The Navy also established an initial set of quantitative criteria for assessing acoustic impact to sea turtles from sonar and explosives. These data are utilized in regulatory compliance documents to support quantitative modeling and qualitative assessments of the potential impacts of a variety of Navy stressors on sea turtles and their habitats, including but not limited to the use of sonar, explosives, and military expended materials. Additionally, the Navy employs mitigation measures both at-sea and on Navy installations to minimize the impacts of Navy activities on sea turtles and to promote conservation of their populations. Some of these measures include monitoring sea turtle nests on Navy beaches during the nesting season, having trained lookouts to observe mitigation zones during at-sea training activities to minimize potential effects to sea turtles, and conducting or funding sea turtle research to reduce knowledge gaps. The Navy continues to be a leader in environmental stewardship and utilize the best technology and techniques to improve our compliance and conservation efforts with respect to sea turtle populations. However, deficiencies in the amount or quality of data available, as well as access to research, can significantly limit the Navy's ability to assess and mitigate impacts. As a result, the Navy plans to improve partnerships with international, federal, state, and local agencies; public and private organizations; and academic institutions by engaging stakeholders to maximize our effectiveness in addressing environmental issues.

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.

We tested this prediction by evaluating the diving behavior of animals within social groups off Cape Hatteras, North Carolina, considering diving synchrony a proxy for group membership.

We analyze trade-offs in the longevity, resolution, and continuity of data records from non-recoverable satellite-linked tags on deep-diving Ziphius cavirostris in the context of a behavioral response study of acute noise exposure.

A diverse group of toothed whale species inhabits the pelagic habitats of the western North Atlantic, competing for overlapping prey resources. Historical data deficits have limited fundamental research into many of these species, such as establishing baselines of distribution and abundance, so their occurrence and habitat use patterns are not well characterized. Periodic cycles in activity have been reported at a range of temporal scales for odontocetes in other regions, such as seasonal movements, foraging activity modulated by lunar cycles, and diel activity patterns. A variety of spatial, temporal, and behavioral separation strategies have also been observed among predator guilds in both marine and terrestrial systems, and these may also contribute to observed spatiotemporal patterns in activity. Recently, passive acoustic data has been applied to monitor odontocete species continuously, with improved detection and species discrimination for some cryptic species. We used a long-term passive acoustic data set collected at sites spanning the western North Atlantic shelf-break region to quantify presence and characterize seasonal, lunar, and diel activity patterns for 10 species. Our results demonstrated strong regional preferences and clear patterns of spatiotemporal separation between species with similar foraging ecology. Latitudinal shifts in seasonal presence peaks may suggest meridional seasonal migrations for some dolphin species. We also observed strong diel activity patterns that were modulated by both seasonal and lunar cycles. This study reveals complex behavioral patterns arising in response to natural cycles playing out over multiple temporal scales and provides new insights into habitat partitioning among toothed whale species.

A combination of machine learning and expert analyst review was used to detect odontocete echolocation clicks, identify dominant click types, and classify clicks in 32 years of acoustic data collected at 11 autonomous monitoring sites in the western North Atlantic between 2016 and 2019. Previously-described click types for eight known odontocete species or genera were identified in this data set: Blainville’s beaked whales (Mesoplodon densirostris), Cuvier’s beaked whales (Ziphius cavirostris), Gervais’ beaked whales (Mesoplodon europaeus), Sowerby’s beaked whales (Mesoplodon bidens), and True’s beaked whales (Mesoplodon mirus), Kogia spp., Risso’s dolphin (Grampus griseus), and sperm whales (Physeter macrocephalus)

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)

Remote biopsy sampling is a common method used to obtain tissue samples from wild cetaceans. Using this technique, researchers typically obtain a small sample of skin and blubber using a biopsy tip fired from a crossbow or modified air rifle. Analysis of these tissues can provide important information on specific identity, sex, pollutant levels, diet, and reproductive status, which are critical to studies of free-ranging cetaceans. Biopsy sampling is generally considered to be a relatively benign procedure, but all prior attempts to evaluate its impact have been subjective assessments of the behavioral response of individuals at the surface. The goal of the present study is to provide a quantitative assessment of the immediate effects of biopsy attempts on the behavior of short-finned pilot whales (Globicephala macrorhynchus) equipped with digital acoustic recording tags (DTags) off Cape Hatteras, North Carolina. A biopsy attempt was defined as any instance of contact between a biopsy dart with an animal. A series of five metrics was examined to determine if behavior of whales was affected by a biopsy attempt, including: foraging behavior (number of dives, depth, and number of prey capture attempts); time spent within 3 m of the surface; fine-scale body orientation; fluke rate and amplitude; and group vocalization rate. The short-term reactions to biopsy attempts appear to be ephemeral and should not compromise the fitness of the animal, although the effects of increasing the group vocalization rate after a biopsy attempt should be examined further. The results of this analysis provide the first subsurface, quantitative assessment of the short-term effects of biopsy sampling on cetaceans.

Remote biopsy sampling has been used for almost 40 yr (Winn et al. 1973) to obtain tissue samples for various analyses, and is particularly important because most cetaceans are difficult or impossible to capture safely at sea (Noren and Mocklin 2011). It is generally assumed that there are few, if any, detrimental effects on the fitness of sampled animals. In support of this assumption, there has only been one documented case of death of a cetacean from a biopsy dart (Bearzi 2000), although it is possible deaths have occurred that have not been described in the published literature. Failure of the dart stopper and the poor body condition of the common dolphin (Delphinus delphis) were believed responsible for the death of this animal, as the dart penetrated through its thin blubber layer.

This report represents one facet of a collaborative 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.