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The goal of the Bio-ICE Task Team, convened from July 2020 - January 2022, was to advance the integration of biological observations from local, regional, and federal sources using best practices to inform national needs and ultimately feed into GOOS data visualizations and reporting. Using the GOOS marine mammals and corals EOVs as examples, the Task Team sought to: 1. Reconcile U.S. federal collection of these variables with GOOS EOVs and the Group on Earth Observations’ EBVs, identifying synergies in spatial and temporal observing requirements and with existing observation infrastructure and delivery, including use of documented best practices and standards. 2. Identify and improve pathways for data flow for observations of these variables from the IOOS Regional Associations and federal sources into common data portals. This included a focus on identifying and implementing best practices for standardized data collection and delivery adhering to the FAIR and CARE data principles, as appropriate. The Task Team effort focused on corals and marine mammals to ensure the work of the task team was achievable within the time frame. These two EOVs were selected because of their importance to multiple stakeholders, as well as offering opportunities to tie-in to several critical U.S. priorities in ocean science. While the team chose this focus, it acknowledged that there are activities and communities working to advance the other biology and ecosystem essential variables in ways that might be similar to or synergistic with the task team, such as SCOR Working Group 158: Coordinated Global Research Assessment of Seagrass System (C-GRASS), global efforts to coordinate ocean sound monitoring and data, GOOS BioEco panel community workshops and ongoing panel activities, and other efforts worth tracking or considering for future engagement with IOOC.

Marine mammals are wide-ranging, relatively long-lived organisms that play a crucial role in maintaining healthy ocean ecosystems. Often referred to as ecosystem engineers and sentinel species in marine ecosystems, these charismatic megafauna feed at a variety of trophic levels, affecting food web dynamics and cycling of chemicals and nutrients in the water column as well as in benthic habitats, both nearshore and in the deep ocean. An understanding of their abundance and distribution is an essential starting point for evaluating their role in ocean ecosystems. Accordingly, marine mammals have been included among key variables to monitor in ocean observing systems, from core variablesfor the U.S. Integrated Ocean Observing System (IOOS) to an Essential Ocean Variable (EOV)for the Global Ocean Observing System (GOOS). They also contribute to several Essential Biodiversity Variables (EBVs)for the Group on Earth Observations Biodiversity Observation Network (GEO BON). Further, evaluation of the health of marine mammal populations will help deliver societal benefits by contributing to the UN Decade of Ocean Science for Sustainable Development; informing reporting activities such as the World Ocean Assessment; and supporting achievement of Sustainable Development Goal 14, the post-2020 framework for the Convention for Biological Diversity, and a new treaty for conservation and sustainable use of marine biodiversity beyond national jurisdiction. The goal of this Interagency Ocean Observation Committee task team was to advance the integration of existing biological observations from local, regional, and federal sources using best practices to inform national needs and ultimately feed seamlessly into the Global Ocean Observing System, as appropriate. To accomplish this goal the subgroup focused on marine mammals to: 1. Reconcile the IOOS core biological variables with GOOS EOVs and the GEO BON EBVs, identifying where there are clear synergies in terms of spatial and temporal observing requirements and existing observation infrastructure and delivery including best practices/standards. 2. Identify and improve pathways for data flow for observations of these variables from Federal sources, such as the stock assessments conducted by NMFS and FWS, into IOOS with a focus on identifying and implementing best practices surrounding standardized data collection and delivery adhering to the FAIR and CAREdata principles, as appropriate.

Passive acoustic monitoring of ocean soundscapes can provide information on ecosystem status for those tasked with protecting marine resources. In 2015, the National Oceanic and Atmospheric Administration (NOAA) established a long-term, continuous, low-frequency (10 Hz-2 kHz) passive acoustic monitoring site in the Cordell Bank National Marine Sanctuary (CBNMS), located offshore of the central United States of America (U.S.) west coast, near San Francisco, CA. The California Current flows southward along the coast in this area, supporting a diverse community of marine animals, including several baleen whale species. Acoustic data analysis revealed that both large vessels and vocalizing baleen whales contribute to the ambient soundscape of the CBNMS. Sound levels fluctuated by month with the highest levels in the fall and lowest levels in the summer. Throughout the year, very low-frequency (10-100 Hz) sound levels were most variable. Vessels and whales overlap in their contributions to ambient sound levels within this range, although vessel contributions were more omnipresent, while seasonal peaks were associated with vocalizing whales. This characterization of low-frequency ambient sound levels in the CBNMS establishes initial baselines for an important component of this site's underwater soundscape. Standardized monitoring of soundscapes directly supports NOAA's ability to evaluate and report on conditions within national marine sanctuaries.

Passive acoustic data collection has grown exponentially over the past decade resulting in petabytes of data that document our ocean soundscapes. This effort has resulted in two big data challenges: (1) the curation, management, and global dissemination of passive acoustic datasets and (2) efficiently extracting critical information and comparing it to other datasets in the context of ecosystem-based research and management. To address the former, the NOAA National Centers for Environmental Information recently established an archive for passive acoustic data. This fast-growing archive currently contains over 100 TB of passive acoustic audio files mainly collected from stationary recorders throughout waters in the United States. These datasets are documented with standards-based metadata and are freely available to the public. To begin to address the latter, through standardized processing and centralized stewardship and access, we provide a previously unattainable comparison of first order sound level-patterns from archived data collected across three distinctly separate long-term passive acoustic monitoring (PAM) efforts conducted at regional and national scales: NOAA/National Park Service Ocean Noise Reference Station Network, the Atlantic Deepwater Ecosystem Observatory Network, and the Sanctuary Soundscape Monitoring Project. Nine sites were selected from these projects covering the Alaskan Arctic, Northeast and Central Pacific, Gulf of Mexico, Caribbean Sea, and Mid and Northwest Atlantic. Sites could generally be categorized into those strongly influenced by anthropogenic noise (e.g., vessel traffic) and those that were not. Higher sound levels, specifically for lower frequencies (

The National Oceanic and Atmospheric Administration (NOAA)/National Park Service (NPS) Ocean Noise Reference Station (NRS) Network is an array of currently twelve calibrated autonomous passive acoustic recorders. The first NRS was deployed in June 2014, and eleven additional stations were added to the network during the following two years. The twelve stations record data that can be used to quantify baseline levels and multi-year trends in ocean ambient sound across the continental United States, Alaska, Hawaii, and island territories within and near to the United States Exclusive Economic Zone (U.S. EEZ). The network provides multi-year, continuous observations of low-frequency underwater sound between 10 Hz and 2000 Hz to capture anthropogenic, biological, and geophysical contributions to the marine soundscape at each location. Comparisons over time and among recording sites will provide information on the presence of calling animals and the prevalence of abiotic and anthropogenic activities that contribute to each soundscape. Implementation of the NRS Network advances broad-scale passive acoustic sensing capabilities within NOAA and the NPS and is an important tool for monitoring protected areas and marine species and assessing potential environmental impacts of anthropogenic noise sources. This analysis focuses on the first year of recordings and captures the wide variability of low-frequency sound levels among and within individual NRS sites over time. Continued data collection will provide information on long-term, low-frequency sound level trends within or near the U.S. EEZ and will be used to explore the value of using soundscape analysis to inform management and mitigation strategies.

Passive acoustic data collection has grown exponentially over the past decade resulting in petabytes of data that document our ocean soundscapes. This effort has resulted in two big data challenges: the curation, management, and global dissemination of passive acoustic datasets and efficiently extracting critical information and comparing it to other datasets in the context of ecosystem-based research and management. To address the former, the NOAA National Centers for Environmental Information established a passive acoustic data archive, which contains over 100 TB of audio files mainly collected from stationary recorders throughout waters in the U.S. These datasets are documented with standards-based metadata and are freely available to the public. To begin to address the latter, through standardized processing and centralized stewardship and access, we will present a previously unattainable comparison of first order sound level-patterns from archived data collected across three distinctly separate long-term passive acoustic monitoring efforts conducted at regional and national scales: NOAA/National Park Service Ocean Noise Reference Station Network, the NOPP-funded Atlantic Deepwater Ecosystem Observatory Network, and the NOAA-Navy Sanctuary Soundscape Monitoring Project. Further, we will propose the next frontier for scalable data stewardship, access, and processing flow to help the community collaboratively move forward.

Low-frequency noise that is part of the acoustic environment for baleen whales has increased in many areas of the Northeast Pacific Ocean that contain whale habitat. We conducted a spatially explicit risk assessment of noise from commercial shipping to blue, fin, and humpback whale habitats in Southern California waters and explored how noise is affected by several place-based management techniques: a National Marine Sanctuary, an Area to be Avoided (ATBA), and a Traffic Separation Scheme (TSS). We used shipping data to model noise at 2 frequencies that are part of the acoustic environment for these species and capture the variable contributions from shipping to noise. Predicted noise levels in Southern California waters suggest high, region-wide exposure to shipping noise. Our risk assessment identified several areas where the acoustic environment may be degraded for blue, fin, and humpback whales because their habitat overlaps with areas of elevated noise from shipping traffic and 2 places where blue and humpback whale feeding areas overlap with lower predicted noise levels. One of the places with lower predicted noise occurs in the Channel Islands National Marine Sanctuary (CINMS). Noise has not been directly managed within the CINMS; instead, reduced noise in this portion of the CINMS is likely an ancillary benefit of the ATBA surrounding most of the Sanctuary. Areas of elevated noise in the CINMS also occur, primarily where a TSS intersects the Sanctuaryís boundaries. Our risk assessment framework can be used to evaluate how shipping traffic affects acoustic environments and explore management strategies.

Many marine animals have evolved over millions of years to rely on sound as a fun- damental component of their habitat. Over the last century, increasing noise from human activities has significantly affected the quality of underwater acoustic habitats. These changes can lead to reduced ability to detect and interpret environmental cues used to perform critical life functions (e.g. select mates, find food, maintain group structure and relationships, avoid predators, navi- gate). The National Oceanic and Atmospheric Administration (NOAA), as the US federal agency with primary responsibility for protecting marine animals and their habitats, is developing an agency-wide strategy that emphasizes the ocean spaces that these animals need, and the impor- tance of acoustic conditions in those places. This strategy seeks to reach beyond initial goals of reducing acute impacts due to noise (protecting hearing and reducing physical harm) to better account for the importance of underwater sound in marine ecosystems. This paper outlines sci- ence needs associated with acoustic habitat characterization and the assessment of noise impacts on habitats, which provide information critical to NOAA's prioritization of future place-based research and management. NOAA's spatial management tools are examined relative to acoustic habitat protection goals, which seek to match the ecological scales over which noise is impacting marine wildlife, including endangered species. Recommended actions are identified to address these broad spatial and long temporal scales, including international work on quieting technolo- gies, registries of accumulated noisy events, and an enhanced role for NOAA's National Marine Sanctuaries in science, management, and outreach associated with acoustic habitat protection.

The U.S. Northeast Passive Acoustic Sensing Network (NEPAN) is composed of numerous passive acoustic recorders that provide archived and near-real-time data on acoustically active marine mammals and fish species. It currently stretches from the northern Gulf of Maine into the New York Bight within the northwest Atlantic Ocean. The recorders include moored units that are entirely subsurface and archive audio, units with real-time reporting capabilities via surface buoys, and autonomous vehicles or “gliders.” Data derived from NEPAN will provide long-term year-round information on the presence and spatial distribution of vocal mysticetes and odontocetes, as well as fish. These data will be used to address critical conservation and management needs as well as to reduce threats from anthropogenic activities. Currently, NEPAN will operate from 2014 until late 2017. This listening network is an example of how collaborative scientific efforts and financial investment across many federal agencies can produce a novel far-reaching solution to current scientific information gaps. In this article, we lay out our vision for the future and provide details on the technologies and applications currently used in NEPAN. Furthermore, we present a road map that includes expanding the range of NEPAN throughout the Western North Atlantic Ocean, detecting more species and addressing an even more diverse range of management and conservation applications. However, the reality remains that the continued operation and/or expansion of this type of “listening network” will only be possible in the long term with clear and direct support from the National Oceanic and Atmospheric Administration (NOAA).

Whale entanglement in fishing gear is a global problem, and underwater ropes associated with this gear are often the cause of injuries that can lead to fatalities. Minke whales (Balaenoptera acutorostrata) are especially at risk because they are relatively small, widely distributed, and often occur in coastal habitats where many types of fishing gear are deployed. It is unknown whether minke whales can detect and avoid ropes associated with fishing gear. To address this question we conducted a series of field experiments to measure behavioral responses of nearshore minke whales to underwater ropes simulating crab and whelk fishing gear. We also investigated correlations between whale behaviors and specific environmental variables. Our methods involved both visual and acoustic monitoring of whale behaviors near experimental ropes and buoys of different colors. A remote sensing system was also used to simultaneously monitor oceanographic conditions, record underwater sounds, and capture underwater video of whales swimming near ropes. Minke whales (N = 42) decreased their swimming velocity and altered their bearing when passing near experimental ropes, especially during trials with white and black ropes. Some minkes (N = 7) also altered their underwater swimming trajectories when passing near ropes, and often appeared to produce low-frequency vocalizations. Collectively this information provides strong evidence that minke whales detect and react behaviorally to the presence of underwater ropes that simulate fishing gear in nearshore areas. We hypothesize that visual and perhaps passive acoustic sensory abilities may be the mechanisms behind these rope avoidance behaviors. We recommend that high contrast ropes (white and black) be used with fishing gear in coastal areas to help minimize entanglements of minke and perhaps other whale species.

The National Oceanic and Atmospheric Administration’s (NOAA) National Centers for Environmental Information (NCEI) has recently developed an archive for the long-term stewardship of passive acoustic data. Protocols for archiving passive acoustic data are currently being established in support of the NOAA Ocean Noise Reference Station Network project, and monitoring marine mammals and fish. Archives maintain data, but access to these data is a core mission of NCEI that allows users to discover, query, and analyze the data in new and innovative ways. To facilitate global access to what will be 100s of TB of bioacoustic data, NCEI has partnered with Google Cloud through the NOAA Big Data Project. Cloud-based access to large volumes of data creates the ability to listen to sound files, download more easily, and bring processing routines to the data instead of bringing the data to the processing.

A large scale, systematic, acoustic survey for whales and seals in eastern Antarctic waters was conducted in January-February 2006. During the BROKE-West survey of Southern Ocean waters between 30 and 80° E longitude, an acoustic survey was conducted to complement a traditional visual survey for marine mammal occurrence and distribution. As part of the survey, 145 DIFAR sonobuoys were deployed every 30’ of latitude on north-south transects, and prior to CTD stations on the initial east-west transect. Underwater sound was analyzed for 70 minute samples from each sonobuoy. Blue whales were the most commonly recorded species, identified at 55 of the sonobuoy deployment sites. Other species recorded include: sperm (46 sites), fin (14), humpback (2), and sei (3) whales, and leopard (11) and Ross (17) seals. Large numbers of blue and sperm whales, and all Ross seals were detected on the westernmost two transects, which were the only transects of the survey with relatively extensive sea ice remaining off the continental shelf. Large numbers of blue whales were also detected in the more eastern waters of the survey off the Prydz Bay region, while two detections of pygmy blue whales represent the farthest south these whales have been recorded. Of the relatively few fin whale detections, most occurred in more northerly waters. Fin whale vocalizations from this region were distinctly different than those recorded elsewhere around Antarctica suggesting acoustic recordings may be useful to delineate regional or stock boundaries of this species. Previously undescribed sounds were attributed to Ross seals. Acoustic detections of these and leopard seal sounds indicate these animals venture further from their traditionally described distributions, with vocalizing leopard seals occurring much further north than might be expected. Overall, the results of the sonobuoy survey provide a measure of each species’ relative spatial distribution over the survey area based on acoustic detections, and when combined with the results of the visual survey, will provide a comprehensive view of marine mammal distribution throughout the region during the BROKE-West survey.

To increase understanding of the potential effects of chronic underwater noise in US waters, the National Oceanic and Atmospheric Administration (NOAA) organized two working groups in 2011, collectively called “CetSound,” to develop tools to map the density and distribution of cetaceans (CetMap) and predict the contribution of human activities to underwater noise (SoundMap). The SoundMap effort utilized data on density, distribution, acoustic signatures of dominant noise sources, and environmental descriptors to map estimated temporal, spatial, and spectral contributions to background noise. These predicted soundscapes are an initial step toward assessing chronic anthropogenic noise impacts on the ocean’s varied acoustic habitats and the animals utilizing them.

To help manage chronic and cumulative impacts of human activities on marine mammals, the National Oceanic and Atmospheric Administration (NOAA) convened two working groups, the Underwater Sound Field Mapping Working Group (SoundMap) and the Cetacean Density and Distribution Mapping Working Group (CetMap), with overarching effort of both groups referred to as CetSound, which (1) mapped the predicted contribution of human sound sources to ocean noise and (2) provided region/time/species-specific cetacean density and distribution maps. Mapping products were presented at a symposium where future priorities were identified, including institutionalization/integration of the CetSound effort within NOAA-wide goals and programs, creation of forums and mechanisms for external input and funding, and expanded outreach/education. NOAA is subsequently developing an ocean noise strategy to articulate noise conservation goals and further identify science and management actions needed to support them.

There are no standards for assessment of the cumulative effects of underwater sound. Quantitative assessments typically consider a single source, whereas qualitative assessments may include multiple sources but rarely identify response variables. As a step toward understanding the cumulative effects of underwater sound, we assessed the aggregated sounds of multiple sources received by migrating bowhead whales (Balaena mysticetus). The quantitative method models the sound field from multiple sources and simulates movement of a population through it. The qualitative method uses experts to assess the responses of individuals and populations to sound sources and identify the potential mechanisms. These methods increase the transparency of assessments.

To increase understanding of the potential effects of chronic underwater noise in US waters, the National Oceanic and Atmospheric Administration (NOAA) organized two working groups in 2011, collectively called "CetSound," to develop tools to map the density and distribution of cetaceans (CetMap) and predict the contribution of human activities to underwater noise (SoundMap). The SoundMap effort utilized data on density, distribution, acoustic signatures of dominant noise sources, and environmental descriptors to map estimated temporal, spatial, and spectral contributions to background noise. These predicted soundscapes are an initial step toward assessing chronic anthropogenic noise impacts on the ocean's varied acoustic habitats and the animals utilizing them.

To help manage chronic and cumulative impacts of human activities on marine mammals, the National Oceanic and Atmospheric Administration (NOAA) convened two working groups, the Underwater Sound Field Mapping Working Group (SoundMap) and the Cetacean Density and Distribution Mapping Working Group (CetMap), with overarching effort of both groups referred to as CetSound, which (1) mapped the predicted contribution of human sound sources to ocean noise and (2) provided region/time/species-specific cetacean density and distribution maps. Mapping products were presented at a symposium where future priorities were identified, including institutionalization/integration of the CetSound effort within NOAA-wide goals and programs, creation of forums and mechanisms for external input and funding, and expanded outreach/education. NOAA is subsequently developing an ocean noise strategy to articulate noise conservation goals and further identify science and management actions needed to support them.

There are no standards for assessment of the cumulative effects of underwater sound. Quantitative assessments typically consider a single source, whereas qualitative assessments may include multiple sources but rarely identify response variables. As a step toward understanding the cumulative effects of underwater sound, we assessed the aggregated sounds of multiple sources received by migrating bowhead whales (Balaena mysticetus). The quantitative method models the sound field from multiple sources and simulates movement of a population through it. The qualitative method uses experts to assess the responses of individuals and populations to sound sources and identify the potential mechanisms. These methods increase the transparency of assessments.

Changes in the diving behavior of individual free-ranging juvenile northern elephant seals, Mirounga angustirostris, exposed to the acoustic thermometry of the ocean climate (ATOC) sound source were examined using data loggers. Data loggers were attached to the animals and measured swim speed, maximum depth of dive, dive duration, surface interval, descent and ascent rate, and descent and ascent angle along with sound pressure level (SPL). The ATOC sound source was at a depth of 939 m and transmitted at 195 dB re: 1 microPa at 1 m centered at 75 Hz with a 37.5-Hz bandwidth. Sound pressure levels (SPL) measured at the seal during transmissions averaged 128 dB and ranged from 118 to 137 dB re: 1 microPa for the 60-90 Hz band, in comparison to ambient levels of 87-107 dB within this band. In no case did an animal end its dive or show any other obvious change in behavior upon exposure to the ATOC sound. Subtle changes in diving behavior were detected, however. During exposure, deviations in descent rate were greater than 1 s.d. of the control mean in 9 of 14 seals. Dive depth increased and descent velocity increased in three animals, ascent velocity decreased in two animals, ascent rate increased in one animal and decreased in another, and dive duration decreased in only one animal. There was a highly significant positive correlation between SPL and descent rate. The biological significance of these subtle changes is likely to be minimal. This is the first study to quantify behavioral responses of an animal underwater with simultaneous measurements of SPL of anthropogenic sounds recorded at the animal.

The National Oceanic and Atmospheric Administration’s (NOAA) National Centers for Environmental Information (NCEI) has developed archives for the long-term stewardship of active and passive acoustic data. Water column sonar data have been collected for fisheries and habitat characterization over large spatial and temporal scales around the world, and archived at NCEI since 2013. Protocols for archiving passive acoustic data are currently being established in support of the NOAA Ocean Noise Reference Station Network project, and monitoring marine mammals and fish. Archives maintain data, but access to these data is a core mission of NCEI that allows users to discover, query, and analyze the data in new and innovative ways. Visualization products continue to be developed and integrated into the data access portal so that researchers of varying backgrounds can easily understand the quality and content of these complex data. Spatially and temporally contemporary oceanographic and bathymetric data are also lin...

A recently described population of minke whales (Balaenoptera acutorostrata) offered a unique opportunity to study its acoustic behavior. The often-inquisitive dwarf minke whale is seen on the Great Barrier Reef nearly coincident with its suspected calving and breeding seasons. During drifting encounters with whales, a towed hydrophone array was used to record sounds for subsequent localization of sound sources. Shipboard and in-water observers linked these sounds to the closely circling minke whale. A complex and stereotyped sound sequence, the "star-wars" (SW) vocalization, was recorded during a series of visual and acoustic observations. The SW vocalization spanned a wide frequency range (50 Hz-9.4 kHz) and was composed of distinct and stereotypically repeated units with both amplitude and frequency-modulated components. Broadband source levels between 150 and 165 dB re 1 microPa at 1 m were calculated. Passive acoustic studies can utilize this distinct vocalization to help determine the behavior, distribution, and movements of this animal. While the SW vocalization's function remains unknown, the regularly repeated and complex sound sequence was common in low latitude, winter month aggregations of minke whales. At this early stage, the SW vocalization appears similar to the songs of other whale species and has characteristics consistent with those of reproductive advertisement displays.

For decades, the bio-duck sound has been recorded in the Southern Ocean, but the animal producing it has remained a mystery. Heard mainly during austral winter in the Southern Ocean, this ubiquitous sound has been recorded in Antarctic waters and contemporaneously off the Australian west coast. Here, we present conclusive evidence that the bio-duck sound is produced by Antarctic minke whales ( Balaenoptera bonaerensis ). We analysed data from multi-sensor acoustic recording tags that included intense bio-duck sounds as well as singular downsweeps that have previously been attributed to this species. This finding allows the interpretation of a wealth of long-term acoustic recordings for this previously acoustically concealed species, which will improve our understanding of the distribution, abundance and behaviour of Antarctic minke whales. This is critical information for a species that inhabits a difficult to access sea-ice environment that is changing rapidly in some regions and has been the subject of contentious lethal sampling efforts and ongoing international legal action.

Date of Acceptance: 23/09/2013 Male humpback whales produce a long, complex, and stereotyped song on low-latitude breeding grounds; they also sing while migrating to and from these locations, and occasionally in high-latitude summer feeding areas. All males in a population sing the current version of the constantly evolving display and, within an ocean basin, populations sing similar songs; however, this sharing can be complex. In the western and central South Pacific region there is repeated cultural transmission of song types from eastern Australia to other populations eastward. Song sharing is hypothesized to occur through several possible mechanisms. Here, we present the first example of feeding ground song from the Southern Ocean Antarctic Area V and compare it to song from the two closest breeding populations. The early 2010 song contained at least four distinct themes; these matched four themes from the eastern Australian 2009 song, and the same four themes from the New Caledonian 2010 song recorded later in the year. This provides evidence for at least one of the hypothesized mechanisms of song transmission between these two populations, singing while on shared summer feeding grounds. In addition, the feeding grounds may provide a point of acoustic contact to allow the rapid horizontal cultural transmission of song within the western and central South Pacific region and the wider Southern Ocean. Publisher PDF

International audience; Understanding the seasonal movements and distribution patterns of migratory species over ocean basin scales is vital for appropriate conservation and management measures. However, assessing populations over remote regions is challenging, particularly if they are rare. Blue whales (Balaenoptera musculus spp) are an endangered species found in the Southern and Indian Oceans. Here two recognized subspecies of blue whales and, based on passive acoustic monitoring, four ''acoustic populations'' occur. Three of these are pygmy blue whale (B.m. brevicauda) populations while the fourth is the Antarctic blue whale (B.m. intermedia). Past whaling catches have dramatically reduced their numbers but recent acoustic recordings show that these oceans are still important habitat for blue whales. Presently little is known about the seasonal movements and degree of overlap of these four populations, particularly in the central Indian Ocean. We examined the geographic and seasonal occurrence of different blue whale acoustic populations using one year of passive acoustic recording from three sites located at different latitudes in the Indian Ocean. The vocalizations of the different blue whale subspecies and acoustic populations were recorded seasonally in different regions. For some call types and locations, there was spatial and temporal overlap, particularly between Antarctic and different pygmy blue whale acoustic populations. Except on the southernmost hydrophone, all three pygmy blue whale acoustic populations were found at different sites or during different seasons, which further suggests that these populations are generally geographically distinct. This unusual blue whale diversity in sub-Antarctic and sub-tropical waters indicates the importance of the area for blue whales in these former whaling grounds.

In order to compare long-term changes and trends in soundscapes around the United States, a multi-year network of identical autonomous passive acoustic recording systems, the Ocean Noise Reference Station (NRS) Network, has been established. In partnership with the National Oceanic and Atmospheric Administration (NOAA) Office of Oceanic and Atmospheric Research, NOAA Pacific Marine Environmental Laboratory, NOAA National Marine Fisheries Service, NOAA Office of National Marine Sanctuaries, and the National Park Service, hydrophone moorings were deployed in 12 discrete soundscapes in the Northeast Pacific and Northwest Atlantic oceans to record underwater ambient sound levels in the 10 to 2200 Hz frequency range. This initial analysis utilized the first year of available data from the NRS deployed in Stellwagen Bank National Marine Sanctuary (SBNMS), a busy area for both natural and anthropogenic activity. Preliminary results indicate that: (1) broadband (10-2200 Hz) ambient sound levels at SBNMS are stabl...

Time averaged narrow-band noise near 27 Hz produced by vocalizations of many distant Antarctic blue whales intensifies seasonally from early February to late October in the ocean off Australia's South West. Spectral characteristics of long term patterns in this noise band were analyzed using ambient noise data collected at the Comprehensive Nuclear-Test-Ban Treaty hydroacoustic station off Cape Leeuwin, Western Australia over 2002-2010. Within 7 day averaged noise spectra derived from 4096-point FFT (∼0.06 Hz frequency resolution), the -3-dB width of the spectral peak from the upper tone of Antarctic blue whale vocalization was about 0.5 Hz. The spectral frequency peak of this tonal call was regularly but not gradually decreasing over the 9 years of observation from ∼27.7 Hz in 2002 to ∼26.6 Hz in 2010. The average frequency peak steadily decreased at a greater rate within a season at 0.4-0.5 Hz/season but then in the next year recovered to approximately the mean value of the previous season. A regression analysis showed that the interannual decrease rate of the peak frequency of the upper tonal call was 0.135 ± 0.003 Hz/year over 2002-2010 (R(2) ≈ 0.99). Possible causes of such a decline in the whale vocalization frequency are considered.

The potential for seismic airgun "shots" to cause acoustic trauma in marine mammals is poorly understood. There are just two empirical measurements of temporary threshold shift (TTS) onset levels from airgun-like sounds in odontocetes. Considering these limited data, a model was developed examining the impact of individual variability and uncertainty on risk assessment of baleen whale TTS from seismic surveys. In each of 100 simulations: 10000 "whales" are assigned TTS onset levels accounting for: inter-individual variation; uncertainty over the population's mean; and uncertainty over weighting of odontocete data to obtain baleen whale onset levels. Randomly distributed whales are exposed to one seismic survey passage with cumulative exposure level calculated. In the base scenario, 29% of whales (5th/95th percentiles of 10%/62%) approached to 1-1.2 km range were exposed to levels sufficient for TTS onset. By comparison, no whales are at risk outside 0.6 km when uncertainty and variability are not considered. Potentially "exposure altering" parameters (movement, avoidance, surfacing, and effective quiet) were also simulated. Until more research refines model inputs, the results suggest a reasonable likelihood that whales at a kilometer or more from seismic surveys could potentially be susceptible to TTS and demonstrate that the large impact uncertainty and variability can have on risk assessment.

A song playback experiment to singing minke whales on the Great Barrier Reef was carried out. Songs were played to singers at ranges of 0.5-2.0km A remotely monitored sonobuoy array was used to monitor whale movements and singing behavior. Upon initiation of playbacks, whales either moved away from the playback vessel, or stopped singing, indicating song is likely used to maintain spacing between singing individuals.

All underwater activities of diving mammals are constrained by the need for surface gas exchange. Our aim was to measure respiratory rate (fB) and heart rate (fH) at the surface between dives in free-ranging northern elephant seals Mirounga angustirostris. We recorded fB and fH acoustically in six translocated juveniles, 1.8–2.4 years old, and three migrating adult males from the rookery at Año Nuevo, California, USA. To each seal, we attached a diving instrument to record the diving pattern, a satellite tag to track movements and location, a digital audio tape recorder or acoustic datalogger with an external hydrophone to record the sounds of respiration and fH at the surface, and a VHF transmitter to facilitate recovery. During surface intervals averaging 2.2±0.4 min, adult males breathed a mean of 32.7±5.4 times at a rate of 15.3±1.8 breaths min−1 (means ± S.D., N=57). Mean fH at the surface was 84±3 beats min−1. The fB of juveniles was 26 % faster than that of adult males, averaging 19.2±2.2 breaths min−1 for a mean total of 41.2±5.0 breaths during surface intervals lasting 2.6±0.31 min. Mean fH at the surface was 106±3 beats min−1. fB and fH did not change significantly over the course of surface intervals. Surface fB and fH were not clearly associated with levels of exertion, such as rapid horizontal transit or apparent foraging, or with measures of immediately previous or subsequent diving performance, such as diving duration, diving depth or swimming speed. Together, surface respiration rate and the duration of the preceding dive were significant predictors of surface interval duration. This implies that elephant seals minimize surface time spent loading oxygen depending on rates of oxygen uptake and previous depletion of stores.

Sound is the most effective means of communication in the ocean. A uniquely inquisitive minke whale population on the northern Great Barrier Reef presents an unprecedented research opportunity to study minke acoustics. In 1997, we used vessel-based recordings to link the minke to a wide variety of sounds. In 1998 and 1999, we expanded the study to include a remote acoustic array to monitor and track one particularly interesting vocalization that can be used for long distance communication. Our vessel-based recordings have given us the largest database of minke sounds yet reported. By matching the acoustics with observed behaviors, group structure and identification data, we are beginning to shed light on the possible functions of these sounds. Our remote array work is revealing how these sounds are used over larger scales by allowing us to localize and track the movements of vocalizing animals. We have been able to look at the physical and acoustic interaction between multiple vocalizing whales for distances of over 5 km and times longer than 2 hours.

With current, wide-spread coastal construction projects and the predicted development of offshore wind energy, there are concerns regarding the potential impacts of underwater sound associated with pile driving activities on protected marine species. The National Marine Fisheries Service (NMFS) works to conserve, protect, and recover a variety of marine species, including marine mammals, marine and anadromous fishes, and sea turtles, protected under the Marine Mammal Protection Act (MMPA) and/or Endangered Species Act (ESA). In order to make management decisions for these protected species, we rely on scientific data to inform our policy. However, there are many challenges, including determining appropriate acoustic criteria and metrics for injury and behavioral harassment for impact and vibratory pile driving activities; understanding acoustic propagation in complex environments, especially shallow, coastal areas and throughout sediments; establishing appropriate protocols to mitigate and monitor impacts; and managing uncertainty for the broad number of species under our jurisdiction, who use and depend on sound (pressure and particle motion) in a variety of ways. Thus, we work collaboratively with other federal, state, and local government agencies, academia, nongovernmental agencies, and industry to best assess and manage risk from these activities.

The description of minke whale (Balaenoptera acutorostrata) vocalizations is sparse with little recent study. In addition, the minke and some of its assumed vocalizations are not definitively linked. To address this problem, recordings were made at a unique site off the Great Barrier Reef where minkes maintain long, close contacts (to 10 h) with vessels. During these encounters a 200‐m, four‐element hydrophone array (Hi‐Tech HTI‐SSQ41B, 10 Hz–30 kHz) was deployed and digitally recorded onto a Tascam DA‐38 (0–22 kHz). Time of arrival differences between hydrophones were used to obtain hyperbolic fixes on nearby sound sources. With this method, a new vocalization consisting of three short pulses (pulse duration 100 ms, peak energy 200–250 Hz, with significant energy between 1.5 and 2 kHz) followed by a slight upsweep (trail of 1 s) has been definitively linked to the minke. Source levels of at least 155 dB re: 1 μPa were estimated. Similar vocalizations with varying pulse numbers (to at least 7), and low fr...

These mammals need to call long-distance when it comes to attracting females. The low-frequency vocalizations of fin and blue whales are the most powerful and ubiquitous biological sounds in the ocean1,2. Here we combine acoustic localization and molecular techniques to show that, in fin whales, only males produce these vocalizations. This finding indicates that they may function as male breeding displays, and will help to focus concern on the impact of human-generated low-frequency sounds on recovering whale populations.