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.

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

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

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)

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?

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.

Volume contents Endang Species Res 57:325-340 (2025) DOI: https://doi.org/10.3354/esr01423 copied Accounting for sampling bias reveals a decline in abundance of endangered false killer whales in the main Hawaiian Islands Janelle J. Badger Robin W. Baird Devin S. Johnson Amanda L. Bradford Sabre D. Mahaffy Michaela A. Kratofil Tori Cullins Jens J. Currie Stephanie H. Stack Erin M. Oleson ABSTRACT: We estimated abundance of the endangered main Hawaiian Islands (MHI) insular population of false killer whales Pseudorca crassidens from 1999-2022 using a modeling technique that incorporates animal availability in a capture-recapture analysis. The population was sampled using different sampling methods, resulting in yearly encounter histories of 265 individuals and 53 satellite-tagged whales. Survey effort and animal location data were separately analyzed using kernel density estimators, and the degree of overlap between these 2 processes was used to model detection probability in a Bayesian Jolly-Seber population model. This approach better addresses spatiotemporally variable sampling effort than traditional capture-recapture methods, improving the estimation of reliable abundance trends. Using simulated data, the model was robust to many sampling and ecological complications, such as variable low detectability, unequal tag deployment lengths, and variable social group sizes. Fitting the model to the MHI false killer whale data set, we found that the insular population of false killer whales remains small, with an estimated 139 individuals (95% credible interval, CRI = [114, 162]) in 2022. The population appears to be in decline throughout the study period, with a mean annual percent change of -1.09 (95% CRI = [-2.11, -0.023]) over the entire time series and -3.51 (95% CRI = [-5.08, -1.88]) since 2013, when the population was listed as endangered. Given the magnitude of the decline, identifying which of the many factors affecting this population is most responsible is key in order to guide potential management responses.

In August 2017, a marine mammal monitoring project was carried out combining boat-based field efforts and passive acoustic monitoring on and around the Pacific Missile Range Facility (PMRF). Commander, Pacific Fleet (PACFLT) funded five days of small-boat effort and the National Marine Fisheries Service funded an additional six days of effort. Information obtained was compared to previous sightings during small-boat effort by Cascadia Research Collective (CRC) off Kauai and Niihau, during 1,119 hr of effort (19,194 km) over nine different years from 2003 through 2016 (see Baird 2016)

As part of the long-term United States (U.S.) Navy-funded Marine Species Monitoring Program, from 16–24 August 2022, Cascadia Research Collective (CRC) carried out a vessel-based field effort in conjunction with passive acoustic monitoring undertaken by U.S. Navy (Navy) scientists on and around the underwater hydrophone ranges of the Pacific Missile Range Facility (PMRF).

As part of the long-term United States (U.S.) Navy-funded Marine Species Monitoring Program, from 5-13 August 2023, Cascadia Research Collective (CRC) carried out a vessel-based field effort in conjunction with passive acoustic monitoring undertaken by U.S. Navy (Navy) scientists on and around the underwater hydrophone ranges of the Pacific Missile Range Facility (PMRF).

As part of the long-term United States (U.S.) Navy-funded Marine Species Monitoring Program, from 1-14 August 2021, a combination of boat-based field effort and passive acoustic monitoring was carried out on and around the underwater hydrophone ranges of the Pacific Missile Range Facility (PMRF).

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)

A number of species of resident and non-resident odontocetes use the waters of the Kaulakahi Channel between Kaua‘i and Ni‘ihau, overlapping with the Pacific Missile Range Facility (PMRF). Submarine Command Courses (SCCs) held at PMRF provide an opportunity to assess exposure and measure odontocete reactions to mid-frequency active sonar (MFAS) being used in realistic training scenarios. The primary goal of this assessment was to estimate MFAS received levels (RLs) for satellite tagged odontocetes and determine whether any large-scale movements occurred in response to hull-mounted surface ship MFAS exposure. Two prior reports have used odontocete satellite tag data and information on MFAS use to estimate RLs for animals tagged in 2011 through 2015.

The U.S. Navy’s marine species monitoring program addresses four general topics surrounding the impact of midfrequency active sonar (MFAS) on protected species: occurrence, exposure, response, and consequences. Occurrence of odontocete cetaceans on and around the Pacific Missile Range Facility (PMRF) has been studied for several years using a combination of satellite tags and photo-identification, demonstrating the existence of resident populations of several species of odontocetes and resulting in considerable information on diving behavior and movement patterns of these species.

The Pacific Missile Range Facility (PMRF) off the island of Kaua‘i is the site of regular United States (U.S.) Navy training, some of which involves mid-frequency active sonar (MFAS) use from different types of military sound sources. PMRF includes acoustic instrumentation which allows for passive acoustic monitoring (PAM) capabilities to detect and localize sounds such as vocalizing marine mammals. Recent boat-based studies at PMRF have utilized real-time PAM (in conjunction with the Marine Mammal Monitoring on Navy Ranges project) to detect odontocetes for vectoring a field tagging boat to groups in order to increase the likelihood of deploying satellite tags. The resulting data have allowed for an assessment of habitat use and range of several different species. Some of these boat-based tagging efforts were timed to occur just before Submarine Commanders Courses (SCCs) occurring on PMRF so that animal movements and diving behavior could be measured both before and during sonar use.

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

Movements and Spatial Use of Satellite‐tagged Odontocetes in the Western Main Hawaiian Islands: Results of Fieldwork Undertaken off O‘ahu in October 2010 and Kaua‘i in February 2011

Although considerable information is available on residency patterns and spatial use of odontocetes in the eastern half of the Hawai‘i Range Complex (HRC), much less is known about odontocetes in the western half of the HRC. In the second year of a three-year effort in the western main Hawaiian Islands we undertook surveys off Kaua‘i and Ni‘ihau in July/August 2011, to examine spatial use and residency patterns using satellite tags, to provide visual verification of acoustically-detected odontocetes on the Pacific Missile Range Facility (PMRF), and to obtain individual identification photographs and biopsy samples for assessment of population identity and structure.

As part of an assessment of habitat use and movements of odontocetes being undertaken in the western half of the main Hawaiian Islands (see Baird et al. 2011, 2012), field operations funded by Commander, U.S. Navy Pacific Fleet were undertaken off of Kaua‘i in January 2012. There were two primary goals of these operations: 1) providing species verification for acoustic detections by the Marine Mammal Monitoring on Navy Ranges (M3R) project on the Pacific Missile Range Facility (PMRF) hydrophone range (see Moretti et al. 2012); and 2) deploying satellite tags prior to a Submarine Commanders Course (SCC) training event to be undertaken off Kaua‘i in February 2012.

Here we combine results of field efforts funded through the U.S. Navy’s Living Marine Resources Program (through a three-year grant from the Naval Postgraduate School) as well as additional field time in the study area in 2011 and 2012 funded through the Pacific Islands Fisheries Science Center and Commander, Pacific Fleet. We also utilize results from research efforts in the eastern main Hawaiian Islands, off Lāna‘i, Maui, and Hawai‘i Island, to help interpret results from photo-identification and satellite tagging.

A joint project in February 2013 of the Pacific Missile Range Facility (PMRF) combined passive acoustic monitoring and boat-based field efforts. There were 1,010 kilometers (km) (55.9 hours [hr]) of small-vessel field effort over the course of the 8-day project. Of the 55.9 hr of survey effort, 64.2 percent was spent within the PMRF instrumented hydrophone range boundaries, and 14.8 percent of the effort was in depths greater than 1,000 meters (m).

A joint project in July and August 2013 on and around the Pacific Missile Range Facility (PMRF) combined passive acoustic monitoring and boat-based field efforts. There were 671 kilometers (36.6 hours [hr]) of small-vessel survey effort over the course of the 8-day project, with 55.1 percent of time (20.2 hr) spent within the PMRF instrumented hydrophone range boundaries. A total of 33.0 hr of acoustic monitoring coincided with the small-vessel field effort.

A joint project in February 2014 on and around the Pacific Missile Range Facility (PMRF) was carried out utilizing combined passive acoustic monitoring and boat-based field efforts. There were 1,287 kilometers (km) (66.3 hours [hr]) of small-vessel survey effort over the course of the 10 day project, with 44.6 percent of search time (29.6 hr) spent within the PMRF instrumented hydrophone range boundaries. A total of 81.7 hr of acoustic monitoring was undertaken during the field effort. There were 26 sightings of five species of odontocetes, six of which were directed by acoustic detections from the Marine Mammal Monitoring on Navy Ranges (M3R) system.

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

As part of a long-term U.S. Navy-funded marine mammal monitoring program, in February 2016 a combining boat-based field effort and passive acoustic monitoring was carried out on and around the Pacific Missile Range Facility (PMRF). The U.S. Navy funded five days of small-boat effort and the National Marine Fisheries Service funded an additional two days of effort. There were 859 kilometers (49 hours) of small-vessel survey effort over the course of the seven day project.

As part of a long-term U.S. Navy-funded marine mammal monitoring program, in August 2017 a combination of boatbased field effort and passive acoustic monitoring was carried out on and around the Pacific Missile Range Facility (PMRF) off Kaua‘i prior to a Submarine Command Course scheduled for mid-August 2017. The U.S. Navy funded five days of small-boat effort and the National Marine Fisheries Service funded an additional six days of effort. There were 1,113 kilometers (77.4 hours) of small-vessel survey effort over the course of the 11 day project.

As part of a long-term U.S. Navy-funded marine mammal monitoring program, in August 2018 a combination of vessel-based field effort and passive acoustic monitoring was carried out on and around the Pacific Missile Range Facility (PMRF) Kaua‘i prior to a Submarine Commander Course scheduled for mid-August 2018. The purpose of the monitoring effort was to assess the spatial movement patterns and habitat use of cetaceans that are exposed to mid-frequency active sonar and how those patterns influence exposure and potentially responses.

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

We assess spatiotemporal overlap between false killer whales and nearshore fisheries in Hawai‘i to identify fisheries and regions where interactions are most likely to occur. Interactions with fisheries was cited as the greatest threat to this population's viability as a result of growing evidence over recent decades. We used false killer whale location data from 38 satellite tag deployments (2007–2018) and commercial fishery catch logs from a corresponding period to develop fishery overlap indices (FOIs) from a perspective that should reflect the experience of local fishermen

Currently a single stock of short-finned pilot whales is recognized in Hawaiian waters, with an estimated abundance of over 12,000 individuals in the EEZ. However, preliminary genetic results suggest that pilot whales around the main Hawaiian Islands are reproductively isolated from those elsewhere in the tropical Pacific. Since the type and extent of anthropogenic interactions varies both among the main Hawaiian Islands and offshore, we test the hypothesis that there is only a single stock of this species in Hawai‘i using a combination of association analyses of photo-identification data and movement/habitat use analyses from satellite tags. Photographs over 13 years included over 6,500 identifications of 868 distinctive individuals. Satellite tag data from 64 deployments averaged 37 days (max=228 days). Combining tag and association analyses indicate individuals do not mix freely among the islands and suggest the existence of three socially isolated but partially overlapping insular communities and an offshore population. The ranges of the three insular communities are from Ni‘ihau to western O‘ahu, from O‘ahu to Lana‘i, and primarily off Hawai‘i Island. Tagged individuals from these insular communities (n=61 deployments) remained an average of 57.5 km from their tagging location, with a grand mean of depth used and distance from shore of 1,564 m and 15.2 km, respectively. Evidence for an offshore population comes from three individuals tagged in two isolated social clusters with mean distances from their tagging locations of 249 km, with a grand mean of depth used and distance from shore of 4,336 m and 81.1 km (max=381 km) respectively. Anthropogenic interactions vary among the population ranges, with long-line fishing in offshore waters, Navy activities primarily off Ni‘ihau, Kaua‘i and O‘ahu, and vessel-based whale watching and swim-with operations primarily off Hawai‘i Island. As each community is exposed to different anthropogenic threats they should be managed independently.

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.

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

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

Three subsurface passive acoustic moorings were deployed in the western Gulf of Alaska on the EcoFOCI fall mooring cruise onboard the F/V Aquila 15 Aug – 14 Sep 2023; recovery is planned for September 2024, funding permitting. These mooring will allow investigation into the seasonal occurrence of many species of vocalizing marine mammals including North Pacific right (NPRW), blue, fin, humpback, minke, gray, sperm, killer, and beaked whales, Dall’s and harbor porpoise, general pinniped sounds, and anthropogenic noise sources such as vessels and seismic airguns. This is important data that the Navy needs to prepare environmental planning documentation, including those for the National Environmental Policy Act (NEPA), Marine Mammal Protection Act (MMPA), and ESA documents and consultations. It is also needed to inform the National Marine Fisheries Service Alaska Regional Office’s NPRW critical habitat expansion decision. In addition to the field work, processing of existing passive acoustic recordings from three moorings in the WGOA is ongoing, with one site (Barnabus Trough) completed for the high-frequency band. Killer whale vocalizations were detected on 214 of the 358 days with recordings.

In marine ecosystems, cetaceans are large mobile predators that depend on maximizing foraging efficiency. Their presence within a habitat can therefore be strongly related to the modulation of local prey by oceanographic conditions. Understanding how cetaceans are impacted by prey responses to the physical environment is challenging due to the difficulty of collecting presence data of cetaceans and their prey over long, comparable time periods. We used passive and active acoustic recordings collected from moorings within the San Diego Trough, along with physical oceanographic sampling (i.e. in situ, satellite-derived, and ocean general circulation model measurements), to elucidate relationships between cetaceans, their prey, and the physical environment. Our results show that the predator-prey dynamics of some cetaceans within the San Diego Trough are influenced by seasonal changes in the physical oceanographic conditions and processes that shape their prey resources. Specifically, common dolphin Delphinus delphis foraging activity increased during conditions associated with increased presence of diel vertically migrating fish prey. Blue whale Balaenoptera musculus foraging-associated acoustic activity increased during periods with increased presence of mid-water crustacean zooplankton and was replaced with breeding-associated acoustic activity during conditions associated with the waning of mid-water crustacean zooplankton. Fin whale B. physalus foraging-associated calling activity was more complex to model, most likely because these animals have a generalist diet and occupy this area year-round. Our results highlight environmental conditions and features relevant to cetaceans inhabiting this region and may aid in developing better spatially explicit management actions.

Since the closure of a power plant in the southern part of San Diego Bay, a collaborative monitoring effort among the Navy, the National Marine Fisheries Service (NMFS) and others has been underway to better understand changes in the movement and behavior of the green sea turtle so that the Navy and this turtle can continue to share the resources in the bay. San Diego Bay is home to one of the largest U.S. Navy complexes in the world and California’s second largest incorporated city. Today, more than 25 percent of the U.S. Navy fleet is homeported in San Diego. Maintaining readiness in this ecosystem without causing harm to the natural resources is an ongoing challenge. There are a variety of threatened and endangered species that rely on the San Diego Bay ecosystem at different stages of their lives. One of these is the East Pacific green sea turtle. The East Pacific green sea turtle is a federally threatened species in San Diego Bay. While the majority of the population has traditionally lived in the quieter south part of the bay, the turtles may be venturing into areas more frequently used for U.S. Navy, recreational, and commercial activities. An increased presence of turtles outside of the southern portion of the bay may have potential implications for management of this species, as there is a higher likelihood of boat strikes and other potentially adverse human interactions.

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.

NOAA Fisheries’ Hawaiian Monk Seal Research Program (HMSRP) and U.S. Navy Pacific Fleet Environmental initiated a collaborative research effort to investigate potential impacts of naval activities in the HRC. To accomplish this goal, positional data was collected by 13 global positioning system (GPS) telemetry tags deployed over a 2-year period (2010–2011) on 11 individual Hawaiian monk seals, for a total of 38,232 hours (1,593 days).

HDR vessel-based visual monitoring for marine mammals was conducted 1–9 February 2014 in conjunction with Cascadia Research Collective (CRC) satellite-tagging and real time acoustic monitoring by the Marine Mammal Monitoring on Navy Ranges (M3R) team. These efforts were to aid species-validation projects conducted in and around the Pacific Missile Range Facility (PMRF) instrumented range, northwest of Kauai in the Hawaii Range Complex (HRC). The monitoring survey was conducted prior to the commencement of the U.S. Navy’s Submarine Commanders Course (SCC) that took place 17–21 February 2014, which included the use of mid-frequency active sonar.

The telemetry and survey studies managed by the Naval Undersea Warfare Center, Division Newport (NUWCDIVNPT) was initiated in winter 2021 to collect data on harbor seals (Phoca vitulina) and gray seals (Halichoerus grypus) along the U.S. East Coast. The purpose of this field season’s research was to collect baseline data to inform a proposed pinniped behavioral response study and continue long-term pinniped surveys, specifically in the Navy OPAREAS along the northwestern Atlantic coast. A summary of the data collected in previous field seasons can be found in DeAngelis (2023).

The aim of the 2021-2022 field season’s research, Phase II of the Pinniped BRS, was to continue to obtain data to measure baseline behavior to understand the physical or biotic factors that influence the movement and foraging tactics of harbor and gray seals; the amount of time seals spend in specific areas, paying particular attention to Navy OPAREAS; and, the anthropogenic risks (e.g., noise-producing military activities) seals potentially encounter in nearshore and offshore areas.

To meet information needs of the US Navy, Pacific Fleet Environmental, the National Marine Fisheries Service, Marine Mammal Laboratory in collaboration with Washington Department of Fish and Wildlife conducted a study of adult male California sea lions (Zalophus californianus) with two objectives: 1) to estimate the number of sea lions that use Navy Facilities in Puget Sound, Washington and 2) to describe how adult male sea lions utilize the waters of Washington as marine foraging areas. To accomplish this, weekly counts of sea lions were conducted at four Navy Facilities in Puget Sound, Washington (WA) to estimate abundance and satellite dive recorders were deployed on adult male California sea lions to obtain data on the proportion of time the animals were hauled out and their distribution and diving behavior as they foraged in inland and coastal waters.

Navy Research Funded Year Three Project Reports

Whales and dolphins use sound for different functions including echolocation and social communication, and thus changes in sound production patterns are a likely component of any behavioral response to anthropogenic sounds such as military mid-frequency sonar (MFA). To simultaneously log whale and dolphin movements, sound production and reception, and anthropogenic sound exposure levels, we used Dtags (Woods Hole Oceanographic Institution) and bioacoustic probes (Greeneridge Sciences). Tags were deployed on wild, free-ranging cetaceans in Southern California waters. Tagged animals were then exposed to simulated MFA or, as a control, pseudo-random noise (PRN). In total, the August-September 2010 SoCal10 behavioral response study included 28 playbacks: 19 to blue whales (11 MFA, 8 PRN), 5 to fin whales (3 MFA, 2 PRN), 2 to a single sperm whale (1 MFA, 1 PRN), 1 to a Risso’s dolphin (MFA), and 1 to a Cuvier’s beaked whale (MFA). For this analysis we focus first on baleen whale call production and reception rates (particularly blue whale D calls and variable calls) in relation to sound exposure level, dive behavior, and lunge feeding rates. We then examine echolocation-based foraging behavior and social call production by the toothed whales as a function of sound exposure level. This rich dataset, including multiple cetacean species of conservation concern, provides insight into the wide potential range of responses to sound, and the dependence of those responses on ecological, social and behavioral context. Investigations like SoCal10 can help guide inferences for related topics, such as assessment of population effects of anthropogenic noise.

A marine mammal species verification and satellite tagging test was carried out as part of the Marine Mammal Monitoring on Navy Ranges (M3R) program in collaboration with the Cascadia Research Collective from 11 June to 02 August 2012 at the Pacific Missile Range Facility (PMRF). The primary objective of the test was to acoustically detect marine mammals at PMRF and vector observers to vocalizing animals. This allowed the team to: 1) Visually verify at-sea species acoustically detected on the PMRF undersea range 2) Deploy satellite tags on marine mammals prior to the Rim of the Pacific Exercise (RIMPAC) to monitor animals’ movement before, during and after navy training. 3) Photograph animals to create a photo-ID record for the Hawaii Range Complex 4) Collect biological samples (fecal/biopsy) 5) Document group composition and behavior

To better understand the spatial distribution of habitat usage in the Bay by these species, the Navy funded home range analyses of both species based on extant satellite-tagging data for tags deployed from 2014 to 2018.

Understanding the spatial distribution of a species is required to enact effective conservation. Complications to effective conservation can arise when the distributions of multiple target species are non-overlapping. Conservation efforts meant to protect one species may shift threats into the distribution of another species. Two species of marine turtle, loggerhead Caretta caretta and Kemp’s ridley Lepidochelys kempii, are common seasonally in Chesapeake Bay, a large estuary on the US east coast. Both species are protected under the US Endangered Species Act and face spatially complex threats in the region. We created habitat suitability models for these 2 species to inform conservation efforts in the region and explore the extent of overlap be - tween their distributions. Argos satellite tags were deployed on 24 Kemp’s ridley and 10 loggerhead turtles to record animal locations within the Bay. Boosted regression tree models were created for each species using presence-only animal locations, predicting suitable habitat within the Bay. Habitat for Kemp’s ridley turtles was predicted in shallow, coastal areas of the southern Bay as well as in brackish areas of rivers. Loggerhead turtle habitat was predicted to extend farther north than Kemp’s ridley habitat and was generally found in deeper areas of the middle Bay. There is some evidence that these 2 species are partitioning habitat. Any conservation measures adopted to conserve marine turtles in the Chesapeake Bay should consider the habitat of both species holistically to avoid shifting impacts from one species to another.

The study team proposed deploying up to 50 Wildlife Computers satellite-linked telemetry tags per year for 3 years, split evenly between Kemp’s ridley and green sea turtles (or as encounters allow), at several sites along the East Coast ranging from Florida (FL) to Massachusetts (MA). In partnership with several rehabilitation and research groups, the study team aims to collect and record sea turtle behavioral data in multiple representative environments and times of year

Building on Year 1 deployments, Year 2 moved the study toward providing robust, defensible availability bias models for green and Kemp’s ridley sea turtles on the East Coast. The current study results should be interpreted with caution, given the relatively small number of deployments to date, particularly for Kemp’s ridley turtles (n=10 deployments), which limits the available information both spatially and temporally. Collecting 18 months of data and expanding the analysis, compared to 6 months when the 2024 annual report (DiMatteo and Mansfield 2025) was written, reinforced several findings. Availability bias generally increased as the depth threshold at which animals were assumed to be able to be seen increased. This is to be expected as more of the water column is considered to be visible. The availability bias estimates from the 2-m depth histograms and dive behavior were similar.

Understanding the spatial distribution of a species is required to enact effective conservation. Complications to effective conservation can arise when the distributions of multiple target species are non-overlapping. Conservation efforts meant to protect one species may shift threats into the distribution of another species. Two species of marine turtle, loggerhead Caretta caretta and Kemp’s ridley Lepidochelys kempii, are common seasonally in Chesapeake Bay, a large estuary on the US east coast. Both species are protected under the US Endangered Species Act and face spatially complex threats in the region. We created habitat suitability models for these 2 species to inform conservation efforts in the region and explore the extent of overlap between their distributions. Argos satellite tags were deployed on 24 Kemp’s ridley and 10 loggerhead turtles to record animal locations within the Bay. Boosted regression tree models were created for each species using presence-only animal locations, predicting suitable habitat within the Bay. Habitat for Kemp’s ridley turtles was predicted in shallow, coastal areas of the southern Bay as well as in brackish areas of rivers. Loggerhead turtle habitat was predicted to extend farther north than Kemp’s ridley habitat and was generally found in deeper areas of the middle Bay. There is some evidence that these 2 species are partitioning habitat. Any conservation measures adopted to conserve marine turtles in the Chesapeake Bay should consider the habitat of both species holistically to avoid shifting impacts from one species to another.

Kemp's ridley turtles (Lepidochelys kempii) are critically endangered sea turtles that forage seasonally in Chesapeake Bay, a large estuary on the east coast of the United States. Most of the Kemp's ridley turtles foraging in the bay are immature. When tracking these animals, satellite transmitter retention times have been low compared with adult marine turtles of other species. The immature Kemp's ridleys' small size and rapid growth leads to shorter, more variable deployments, limiting the use of data. These limited data leave critical questions remaining about the animals' habitat usage that are difficult to answer without substantially more deployments. A novel sensitivity analysis using simulated deployments indicated that too few animals were tagged with satellite transmitters to identify all possible home-range areas in the Bay.

Spatially explicit estimates of marine species distribution and abundance are required to quantify potential impacts from human activities such as military training and testing, fisheries interactions, and offshore energy development. There are 4 protected species of sea turtle (loggerhead, green, Kemp’s ridley, and leatherback) commonly found along the east coast of the USA, our study area, and which require impact assessments.

In the Pacific, the Marine Mammal Monitoring on Navy Ranges (M3R) program maintains systems that continuously run algorithms to detect, classify and localize marine mammals year-round on the U.S. Navy’s deep-water Southern California Antisubmarine Warfare Range (SOAR) in Southern California and the Pacific Missile Range Facility (PMRF) off Kaua‘i, Hawai‘i. Long-term archive data collected on these ranges allow for numerous types of studies on species inhabiting the ranges, including the monitoring of abundance, behavioral responses to naval activities, and habitat usage. They also provide the opportunity to study ambient sound levels and soundscapes. In FY24 the M3R program had five goals for SOAR and PMRF: Support real-time monitoring of on-water tagging operations Collection and postprocessing of M3R binary archives and periodic broadband recordings Data preservation: conversion of Alesis recordings to M3R packet recorder format SOAR Continuous Active Sonar Behavioral Response Study (CAS BRS) DICASS sonobuoy receiver adaption in preparation for deployment at SOAR.

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

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

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

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

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

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

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

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

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