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)

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

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

This report details part of a multi-institutional monitoring project intended to provide information 3 on the species composition, population identity, density, and baseline behavior of marine 4 mammals and sea turtles present in United States (U.S.) Navy range complexes along the U.S. 5 Atlantic Coast.

We have been conducting ongoing monthly aerial surveys off Cape Hatteras, NC, USA as part of the US Navy's marine species monitoring program in the Atlantic since 2011. We utilize line transect survey methods and extensively photograph all sightings to confirm species identification. Survey tracklines extend from shallow continental shelf waters, across the shelf break, to deep pelagic waters. From May 2011 through December 2014, 26,131km of trackline were flown, and 9,941 individual cetaceans were documented during 437 encounters. Nineteen species of cetaceans, including three mysticetes (Balaenoptera physalus, B. acutorostrata, Megaptera novaeangliae), five deep-divers (Physeter microcephalus, Kogia spp., Ziphius cavirostris, Mesoplodon europaeus, M. mirus), and eleven delphinids (Tursiops truncatus, Stenella frontalis, S. attenuate, S. coeruleoalba, S. clymene, S. longirostris, Steno bredanensis, Peponocephala electra, Lagenodelphis hosei, Grampus griseus and Globicephala macrorhynchus) were encountered. Similar surveys at the adjacent Onslow Bay, NC site yielded only 257 sightings (4,773 individuals representing nine species) despite nearly two times the survey effort flown (48,698km). At Cape Hatteras, minimum abundance estimates (i.e. uncorrected for availability or perception bias) were generated using spatio-temporal density surface modelling for species with sufficient detections. Predicted monthly abundance of T. truncatus varied between 170 (95% confidence interval; 0 - 17,100) and 3,450 (300 - 8,510). Monthly Stenella spp. abundance varied between 110 (0 - 360) and 1,720 (400 - 5,390). Monthly abundance of G. macrorhynchus varied between 10 (0 - 960) and 1,230 (220 - 4,300). These results demonstrate that the waters off Cape Hatteras support both higher diversity and density of cetaceans than adjacent waters along the US Atlantic coast. This site is included in the area of interest identified in six pending permits for large-scale, commercial seismic surveys. We suggest that the high density and diversity of cetaceans at this site warrants a special degree of concern by the US Bureau of Ocean Energy Management.

We conducted monthly aerial surveys off Cape Hatteras, NC, USA as part of an ongoing monitoring project of sites utilized by the US Navy for training and testing activities along the US Atlantic coast. Survey tracklines extend from shallow continental shelf waters, across the continental shelf break, to deep pelagic waters. During surveys we record the geographic position of each marine mammal sighting, take extensive photographs of each animal, and review these images in the lab to confirm species identification. Characteristics utilized to identify beaked whales to species are based upon our sightings of adult males with erupted teeth and from comparisons with images of stranded animals. Between May 2011 and December 2014, we recorded 63 beaked whale sightings, representing 173 individuals. Beaked whales were observed in every month of the year, with the highest number of sightings (n=42) from May through August. The most commonly encountered species, observed in every month of the year, was Ziphius cavirostris (n=36 sightings, 106 individuals). Mesoplodon spp. (n=27 sightings, 67 individuals) were encountered in all months except September and October. Five of these mesoplodont sightings could be identified to species with M. europaeus (n=4 sightings, 12 individuals) and M. mirus (n=1 sighting, 2 individuals) identified from May through July. All beaked whales were encountered along the continental shelf break suggesting a restricted distribution. This area has recently been opened by the US Bureau of Ocean Energy Management to offshore oil and gas exploration. The geographic distribution of beaked whales off Cape Hatteras overlaps the "Manteo Prospect" and is included in the areas of interest identified in six pending permits for large-scale, commercial seismic surveys. The cumulative impacts of seismic surveys are of special concern as deep-diving beaked whales have been shown to be vulnerable to high-amplitude, impulsive anthropogenic sounds.

Beaked whales are vulnerable to the impacts of disturbance from several sources of anthropogenic sound. Here we report the distribution and abundance of beaked whales off Cape Hatteras, North Carolina, U.S.A., an area utilized by the U.S. Navy for training exercises, and of particular interest for seismic geophysical surveys. From May 2011 through November 2015, monthly aerial surveys were conducted at the site. Beaked whales were encountered 74 times (n = 205 individuals) during these surveys. Ziphius cavirostris, the most commonly encountered species, was observed in every month of the year. Mesoplodon spp. were encountered in ten months of the year. Photographs of adult males with erupted teeth permitted six sightings to be identified conclusively as M. europaeus; M. mirus was also photographed just outside the study area. Beaked whale surface densities stratified by depth (0.005–0.007/km2) were among the highest reported in the world for small ziphiids. A quantitative comparison of sightings and stranding records suggests that strandings do not accurately reflect the relative abundance of beaked whale species in this area. We conclude that Cape Hatteras, at the convergence of the Labrador Current and Gulf Stream, is a particularly important year-round habitat for several species of beaked whales.

We conducted monthly aerial surveys off Cape Hatteras, NC, USA as part of an ongoing monitoring project of sites utilized by the US Navy for training and testing activities along the US Atlantic coast. Survey tracklines extend from shallow continental shelf waters, across the continental shelf break, to deep pelagic waters. During surveys we record the geographic position of each marine mammal sighting, take extensive photographs of each animal, and review these images in the lab to confirm species identification. Characteristics utilized to identify beaked whales to species are based upon our sightings of adult males with erupted teeth and from comparisons with images of stranded animals we have confirmed species ID.

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 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.

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).

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.

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 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 2015-2019, in coordination with the Bureau of Ocean Energy Management (BOEM). Likewise, the US 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 Georgia.

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 2015-2019, 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. The work this year was aimed at finalizing components for these key objectives: I. Submit a manuscript describing the methodology of the beaked whale neural net classifier to be cited in future publications utilizing this approach II. Submit a manuscript comparing and contrasting two passive acoustic monitoring methodologies - towed array and shelf break HARPs - concerning beaked whale temporal, spatial presence and diving behavior. III. Utilize passive acoustic data from ten shelf-break environments to evaluate composition and dissimilarity of marine mammal community groups at different latitudes.