Seals (phocids) are generally not thought to produce vocalizations having ultrasonic fundamental frequencies (≥20 kHz), although previous studies could have been biased by sampling limitations. This study characterizes common, yet, previously undescribed, ultrasonic Weddell seal (Leptonychotes weddellii) vocalizations. The vocalizations were identified in more than one year (2017-2018) of broadband acoustic data obtained by a continuously recording underwater observatory in McMurdo Sound, Antarctica. Nine recurrent call types were identified that were composed of single or multiple vocal elements whose fundamental frequencies spanned the ultrasonic range to nearly 50 kHz. Eleven vocal elements had ultrasonic center frequencies (≥20 kHz), including chirps, whistles, and trills, with two elements at >30 kHz. Six elements had fundamental frequencies always >21 kHz. The fundamental frequency of one repetitive U-shaped whistle element reached 44.2 kHz and descending chirps (≥3.6 ms duration) commenced at ≤49.8 kHz. The source amplitude of one fully ultrasonic chirp element (29.5 kHz center frequency) was 137 dB re 1 μPa-m. Harmonics of some vocalizations exceeded 200 kHz. Ultrasonic vocalizations occurred throughout the year with the usage of repetitive ultrasonic chirp-based calls appearing to dominate in winter darkness. The functional significance of these high-frequency vocalizations is unknown.

In the early 1970s, Roger Payne and colleagues developed a non-invasive, shore-based method for collecting data on free-ranging marine mammals in their natural environments. By using a theodolite, or surveyor's transit, they were able to collect data on nearshore marine mammal movement patterns, habitat use, and behavior without any disruption to the animals. As technology advanced, theodolite data collection progressed from analog machines requiring manual data entry to digital equipment linked to computer software that facilitated data management and automated calculations of marine mammal positional information. There are limitations associated with theodolite use, and concurrent data collection methods can contribute information that may not be possible with shore-based research alone. Since the first published research in 1978 using a theodolite to describe the behavioral ecology of dolphins off Argentina, at least 46 species of marine mammals in 36 countries have been tracked by theodolite, and the method continues to be used globally to contribute to non-invasive marine mammal research, conservation, and management.

To investigate the potential impacts of naval mine neutralization exercises (MINEX) on odontocete cetaceans, a long-term passive acoustic monitoring study was conducted at a US Navy training range near Virginia Beach, USA. Bottom-moored acoustic recorders were deployed in 2012-2016 near the epicentre of MINEX training activity and were refurbished every 2-4 months. Recordings were analysed for the daily presence/absence of dolphins, and dolphin acoustic activity was quantified in detail for the hours and days before and after 31 MINEX training events. Dolphins occurred in the area year-round, but there was clear seasonal variability, with lower presence during winter months. Dolphins exhibited a behavioural response to underwater detonations. Dolphin acoustic activity near the training location was lower during the hours and days following detonations, suggesting that animals left the area and/or reduced their signalling. Concurrent acoustic monitoring farther away from the training area suggested that the radius of response was between 3 and 6 km. A generalized additive model indicated that the predictors that explained the greatest amount of deviance in the data were the day relative to the training event, the hour of the day and circumstances specific to each training event.

Long-term passive acoustic monitoring (PAM) was conducted to study Indo-Pacific humpback dolphins, Sousa chinensis, as part of environmental impact assessments for several major coastal development projects in Hong Kong waters north of Lantau Island. Ecological acoustic recorders obtained 2711 days of recording at 13 sites from December 2012 to December 2014. Humpback dolphin sounds were manually detected on more than half of days with recordings at 12 sites, 8 of which were within proposed reclamation areas. Dolphin detection rates were greatest at Lung Kwu Chau, with other high-occurrence locations northeast of the Hong Kong International Airport and within the Lung Kwu Tan and Siu Ho Wan regions. Dolphin detection rates were greatest in summer and autumn (June-November) and were significantly reduced in spring (March-May) compared to other times of year. Click detection rates were significantly higher at night than during daylight hours. These findings suggest high use of many of the proposed reclamation/development areas by humpback dolphins, particularly at night, and demonstrate the value of long-term PAM for documenting spatial and temporal patterns in dolphin occurrence to help inform management decisions.

The naval forces of many nations conduct mine detonation exercises in coastal waters as part of their regular training. These exercises have the potential to disturb, injure or even kill marine mammals occurring in the same area. To address concerns about this possibility at the U.S. Navy’s Virginia Capes (VACAPES) Range Complex, an effort was conducted to monitor odontocete activity at the mine exercise (MINEX) training range using passive acoustic methods. The objectives of the project were to document the daily and seasonal patterns of occurrence of dolphins in the VACAPES MINEX training area, to detect explosions related to MINEX activities, and to investigate potential behavioral and acoustic responses of dolphins to MINEX training events. Dolphins were detected almost daily in the training area. Acoustic activity levels approximately 1 km from the epicenter of training were examined for 22 events and were found to be on average lower during both the day of and the day following the event, suggesting that animals either reduced their signaling, left the area, or both.

Passive acoustic monitoring (PAM) can be an effective tool for studying marine fauna in coral reefs and other ecosystems. We analyzed PAM data from 2006 to 2009 at French Frigate Shoals (FFS) in the Northwestern Hawaiian Islands. We measured received sound pressure levels (SPL) over time within different frequency bands from 0 to 20 kHz, and used automated and manual techniques to detect parrotfish scrapes and cetacean vocalizations. SPLs were greatest overall in the snapping-shrimp-dominated bands above 2.5 kHz, and they increased at night and decreased during cold months. In frequency bands <1.5 kHz, containing mainly fish sounds (and seasonal whale song), SPL peaked at dawn and dusk. Humpback whale song was detected in December through April; occurrence was greater during 2008-2009 than 2006-2007, possibly reflecting an increase in whale density near FFS. Parrotfish bite sounds were detected year-round, and parrotfish foraged most actively during the afternoon. Dolphins were detected on 12-64 % of days per month, with low levels of activity during the day that increased in late afternoon and were highest at night. More frequent detections of dolphins in February/March 2007, October 2008, and February/March 2009 may correspond to pulses of food availability via the mesopelagic prey community. Minke whale "boing" sounds were detected from late October, with one or two peaks in the December-March period; during March 2009 minke whale calls were present nearly every day. The results provide the first long-term record of minke whales in the NWHI, and show the potential of PAM on remote coral reefs to monitor patterns over time of many trophic levels, from herbivores to apex predators.

Limited resources and increasing environmental concerns have prompted calls to identify the critical questions that most need to be answered to advance conservation, thereby providing an agenda for scientific research priorities. Cetaceans are often keystone indicator species but also high profile, charismatic flagship taxa that capture public and media attention as well as political interest. A dedicated workshop was held at the conference of the Society for Marine Mammalogy (December 2013, New Zealand) to identify where lack of data was hindering cetacean conservation and which questions need to be addressed most urgently. This paper summarizes 15 themes and component questions prioritized during the workshop. We hope this list will encourage cetacean conservation-orientated research and help agencies and policy makers to prioritize funding and future activities. This will ultimately remove some of the current obstacles to science-based cetacean conservation.

The views and opinions expressed or implied in this article are those of the author (or authors) and do not necessarily refl ect the position of the National Marine Fisheries Service, NOAA. Abstract—Documenting year-round diversity and distribution of marine mammals off Southern California is important for assessment of effects of potentially harmful anthropogenic activities. Although the waters off Southern California have been surveyed extensively for marine mammals over the past 18 years, such surveys have been periodic and were conducted primarily from summer to fall, thereby missing potential seasonal shifts. We examined seasonal abundance and population density of cetaceans off Southern California from 16 shipboard line-transect surveys conducted quarterly during 2004–08. The study area consisted of 238,494 km2 of coastal, shelf, and pelagic oceanic habitat from nearshore waters to 700 km offshore. Based on 693 encounters of 20 cetacean species, abundance estimates by seasonal period (summer–fall or winter–spring) and depth (shallow: <2000.5 m; deep: ≥2000.5 m) were determined for the 11 most commonly encountered species. The following are values of uncorrected density (individuals/1000 km2, coefficients of variation in parentheses) for the seasonal period and depth with greatest density for a selection of the species in this study: blue whale (Balaenoptera musculus), summer–fall, shallow, 3.2 (0.26); fin whale (B. physalus), summer–fall, shallow, 3.7 (0.30); humpback whale (Megaptera novaeangliae), summer– fall, shallow, 3.1 (0.36); short-beaked common dolphin (Delphinus delphis), summer–fall, shallow, 1319.7 (0.24); long-beaked common dolphin (D. capensis), summer–fall, shallow, 687.9 (0.52); and Dall’s porpoise (Phocoenoides dalli), winter–spring, deep, 48.65 (0.28). Seasonally, density varied significantly by depth for humpback whales, fin whales, and Pacific white-sided dolphins. At least 30 species of cetaceans are found in the California Current (Leatherwood et al., 1982), including 5 species of large whales listed as endangered under the U.S. Endangered Species Act. The abundance and diversity of species along the West Coast of the United States and the continental slope are closely linked to the high level of biological production that is caused by upwelling and mixing of 4 different water masses along the California coast on a seasonal and interannual basis (Reid et al., 1958; Smith et al., 1986; Munger et al., 2009). Although these waters are important to marine fauna, they are also increasingly important to humans who use them for commercial shipping and fishing; oil and gas exploration, development, and production; naval exercises; and recreation. The combined use of these highly productive waters by cetaceans and humans can lead to ships striking large whales (Jensen and Silber, 2003; Berman-Kowalewski et al., 2010), entanglements of cetaceans in fishing gear (Julian and Beeson, 1998; Laist et al., 2001; Carretta et al., 2011b), and disruption of normal behaviors by underwater sound (McDonald et al., 2006; Weilgart, 2007). To assess long-term impacts of fisheries, industry, and ecosystem variability on marine mammals, it is necessary to estimate abundance, understand stock structure, and determine seasonal habitat use by the species that inhabit these waters. Abundance for the summer and fall seasons has been estimated for many cetacean species in waters off California, Oregon, and Washington through the use of ship-based linetransect surveys or mark-recapture techniques of photographically identifi ed whales (Calambokidis and Barlow, 2004; Barlow and Forney, 2007; Carretta et al., 2011b). However, weather conditions make ship-based line-transect surveys diffi cult to conduct year-round, and few studies have quantifi ed habitat and distribution shifts of marine mammals during the 4 National Marine Mammal Laboratory

This project proposes a community standard for the representation of passive acoustic metadata along with a freely available software implementation. Our target audience is the marine mammal community, but the concepts are general and are applicable to a wide variety of taxa. In addition, we address the need to analyze acoustic metadata in the context of other environmental and biological parameters. The implementation provides interfaces to access a wide variety of data available from external services, such solar and lunar rise/set times, sea surface temperature, chlorophyll A, etc., thus permitting extensive data exploration in a workbench environment.

A growing number of passive acoustic monitoring systems have resulted in a wealth of annotation information, or metadata, for recordings. These metadata are semi-structured. Some parameters are essentially mandatory (e.g., time of detection and what was detected) while others are highly dependent upon the question that a researcher is asking. Tethys is a metadata system for spatial-temporal acoustic data that provides structure where it is appropriate and flexibility where it is needed. Networked metadata are stored in an extended markup language (XML) database, and served to workstations over a network. The ability to export summary data to OBIS-SEAMAP is in development. The second purpose of Tethys is to serve as a scientific workbench. Interfaces are provided to networked databases, permitting the import of data from a wide variety of sources, such as lunar illumination or sea ice coverage. Interfaces currently exist for Matlab, Java, and Python. Writing data driven queries using a single interface enables quick data gathering from multivariate sources to address hypotheses. Examples showing the results of analysis of acoustic data from acoustic deployment from 26 sites across the Northern Pacific will be shown.

Humpback whales (Megaptera novaeangliae) wintering in American Samoan waters belong to the endangered Oceania subpopulation (IUCN Red List), but survey effort in this region has been relatively limited. Humpback whale seasonal occurrence was assessed using long-term passive acoustic recordings from March 2008 to July 2009 at Tutuila, the most populous island of American Samoa, and October 2008 to September 2009 at the remote Rose Atoll, 240 km to the east. Humpback whale song occurred from mid-July through November at both locations. For days with song, the mean number of recordings per day with song was significantly greater at Tutuila than at Rose Atoll. Song incidence at Rose Atoll peaked at 82% of recordings/day in late September 2008, and at Tutuila 70-100% of recordings contained song in late August through early September 2009, when recording ceased. Song incidence at Rose Atoll decreased at midday and increased at midnight, whereas there was no significant diurnal pattern at Tutuila. The lower overall incidence of song and its episodic nature at Rose Atoll suggest lower densities of whales traveling through the likely smaller detection area there, whereas greater song incidence and longer peak periods at Tutuila suggest greater whale densities and longer residence times.

We present a method for estimating animal density from fixed passive acoustic detec- tors, and illustrate it by estimating the density of North Pacific right whales Eubalaena japonica in the areas surrounding 3 hydrophones deployed in the southeastern Bering Sea in 2001 to 2002 and 2005 to 2006. Input data were the distances to detected right whale calls, estimated using a normal mode sound propagation model, and call production rate, estimated from encounters by survey vessels with right whale groups. Given the scarcity of information about this highly endangered species, we also extrapolate our results to provide a tentative estimate of the total population size in shelf waters of the eastern Bering Sea. This gives a point estimate of 25 animals (CV 29.1%; 95% confidence interval 13-47), which agrees well with what little is known for this species. We discuss the assumptions underlying the method. Obtaining more reliable values requires a larger sample of randomly located hydrophones, together with improved estimates of call rate.

Visual communication in aquatic environments is limited by light, depth, and turbidity. As a result, sounds are a vital method of communication for a multitude of marine organisms such as shrimp, marine mammals, and fish. Fish possess well-developed auditory systems and can discriminate sounds produced in specific frequency bands (Fay et al. 2008; Kasumyan 2008). Hundreds of fish species are known to produce specialized sounds (Rountree et al. 2003), with many well-studied species found in coral reef ecosystems. Signals of reef fishes are used for communication during agonistic responses (Lobel 1992), territorial defense (Mann and Lobel 1998), feeding (Kasumyan 2008), spawning (Lobel and Mann 1995; Luczkovich et al. 1999, 2008), and courtship (Kaatz and Lobel 1999; Lobel 1992; Lobel and Kerr 1999; Maruska et al. 2007). However, marine environments are becoming subjected to increasing amounts of anthropogenic noise, particularly from shipping and vessel traffic. Little is known about how vessel-generated noise affects the communication and behavior of fish and many other marine species within coral reef ecosystems.

Call source levels, transmission loss, and ambient noise levels were estimated for North Pacific right whale (Eubalaena japonica) up-calls recorded in the southeastern Bering Sea in autumn of 2000 and 2001. Distances to calling animals, needed to estimate source levels, were based on two independent techniques: (1) arrival-time differences on three or more hydrophones and (2) shallow-water dispersion of normal modes on a single receiver. Average root-mean-square (rms) call source levels estimated by the two techniques were 178 and 176 dB re 1 μPa at 1 m, respectively, over the up-call frequency band, which was determined per call and averaged 90 to 170 Hz. Peak-to-peak source levels were 14 to 22 dB greater than rms levels. Transmission loss was approximately 15∗log(10)(range), intermediate between cylindrical and spherical spreading. Ambient ocean noise within the up-call band varied from 72 to 91 dB re 1 μPa(2)/Hz. Under average noise conditions, call spectrograms were detectable for whales at distances up to 100 km, but propagation and detection distance may vary depending on environmental parameters and anthropogenic noise. Obtaining distances to animals and acoustic detection range is a step toward using long-term passive acoustic recordings to estimate abundance for this critically endangered whale population.

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 13:99-109 (2011) - DOI: https://doi.org/10.3354/esr00324 Rare detections of North Pacific right whales in the Gulf of Alaska, with observations of their potential prey P. R. Wade1,*, A. De Robertis1, K. R. Hough1, R. Booth2, A. Kennedy1, R. G. LeDuc3, L. Munger4, J. Napp1, K. E. W. Shelden1, S. Rankin3, O. Vasquez1, C. Wilson1 1Alaska Fisheries Science Center, National Marine Fisheries Service, 7600 Sand Point Way NE, Seattle, Washington 98115, USA 2Center for Conservation Biology, Department of Biology, University of Washington, Seattle, Washington 98195, USA 3Southwest Fisheries Science Center, National Marine Fisheries Service, 3333 N. Torrey Pines Ct, La Jolla, California 92037, USA 4Scripps Institution of Oceanography, La Jolla, California 92037, USA *Email: paul.wade@noaa.gov ABSTRACT: The North Pacific right whale Eubalaena japonica was heavily exploited throughout the Gulf of Alaska by both historical whaling and 1960s illegal Soviet catches. It is now extremely rare in this region (2 sightings between 1966 and 2003 and passive acoustic detections on 6 days out of 80 months of recordings at 7 locations). From 2004 to 2006, 4 sightings of right whales occurred in the Barnabus Trough region on Albatross Bank, south of Kodiak Island, Alaska, USA. Sightings of right whales occurred at locations within the trough with the highest density of zooplankton, as measured by active acoustic backscatter. Net trawls through a high-density demersal layer (~150 to 175 m) revealed large numbers of euphausiids and oil-rich C5-stage copepods. Photo-identification and genotyping of 2 whales failed to reveal a match to Bering Sea right whales. Fecal hormone metabolite analysis from 1 whale estimated levels consistent with an immature male, indicating either recent reproduction in the Gulf of Alaska or movements between the Bering Sea and the Gulf of Alaska. Large numbers of historic catches of right whales occurred in pelagic waters of the Gulf of Alaska, but there have been few recent detections in deep water. Given that there is no other location in the Gulf of Alaska where right whales have been repeatedly seen post-exploitation, the Barnabus Trough/Albatross Bank area represents important habitat for the relict population of North Pacific right whales in the Gulf of Alaska, and a portion of this area was designated as critical habitat under the US Endangered Species Act in 2006. KEY WORDS: North Pacific right whale · Eubalaena japonica · Prey · Gulf of Alaska · Kodiak Island · Whaling Full text in pdf format PreviousNextCite this article as: Wade PR, De Robertis A, Hough KR, Booth R and others (2011) Rare detections of North Pacific right whales in the Gulf of Alaska, with observations of their potential prey. Endang Species Res 13:99-109. https://doi.org/10.3354/esr00324 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 13, No. 2. Online publication date: January 27, 2011 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2011 Inter-Research.

American Samoa is in the process of evaluating the development of a network of marine protected areas (MPAs) to preserve coral reef environments and to prevent the decline of fish populations. Two long-standing MPAs in American Samoa are Rose Atoll Marine National Monument (RAMNM) and coastal marine regions within the National Park of American Samoa (NPSA) system. NPSA includes areas on the populated island of Tutuila, while RAMNM is approximately 130 miles away from the nearest population. Both are protected marine reserves where commercial and public recreational fishing are restricted, although the size and remoteness of the locations create a challenging task for observation and enforcement. A growing management concern over the decline of large fishes and possible illegal fishing has prompted interest in vessel incidence within the two MPAs. We gathered evidence of vessel presence with the use of long-term, autonomous passive acoustic monitoring within the two MPAs. Here we present results of vessel detection within acoustic recordings collected 2009–2010 at RAMNM and 2006–2007 and 2008–2009 at the NPSA Tutuila location. Results from this study highlight the patterns and seasonality of vessel incidence and provide managers with information to assist enforcement.

Monitoring the changing state of marine habitats in remote areas is, in most cases, a challenging task due to limited and/or infrequent opportunities to make direct observations. Passive acoustic monitoring is sometimes the best means of establishing long-term biological trends in such areas. Since 2006, an effort has been underway to monitor the neashore ecosystems of the Northwestern Hawaiian Islands (NWHI) using a network of Ecological Acoustic Recorders. A wide range of acoustic signals are being monitored to infer biological trends and to gauge the relative stability of the ecosystem. Among the variables measured are the acoustic activity of snapping shrimp, the incidence of cetaceans and the extent of spectral and temporal partitioning of the acoustic space by different taxa, measured as the “acoustic entropy” of the habitat. Multiyear time series of the different measures provide baseline levels of biological activity at each location and also reveal periods of anomaly. Observed trends are then examined for corollary relationships with oceanographic and meteorological parameters measured both in situ and remotely. The data obtained thus far are providing valuable insights that will help assess the long-term response of ecosystem in the NWHI to both natural and anthropogenic factors

ESR Endangered Species Research Contact the journal Facebook (Twitter) RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 13:163-172 (2011) - DOI: https://doi.org/10.3354/esr00325 Estimating North Pacific right whale Eubalaena japonica density using passive acoustic cue counting Tiago A. Marques1,2,*, Lisa Munger3, Len Thomas1, Sean Wiggins3, John A. Hildebrand3 1Centre for Research into Ecological and Environmental Modelling, The Observatory, Buchanan Gardens, University of St Andrews, St Andrews KY16 9LZ, UK 2Centro de Estatística e Aplicações da Universidade de Lisboa, Bloco C6, Piso 4, Campo Grande, 1749-016 Lisboa, Portugal 3Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093-0205, USA *Email: tiago@mcs.st-and.ac.uk ABSTRACT: We present a method for estimating animal density from fixed passive acoustic detectors, and illustrate it by estimating the density of North Pacific right whales Eubalaena japonica in the areas surrounding 3 hydrophones deployed in the southeastern Bering Sea in 2001 to 2002 and 2005 to 2006. Input data were the distances to detected right whale calls, estimated using a normal mode sound propagation model, and call production rate, estimated from encounters by survey vessels with right whale groups. Given the scarcity of information about this highly endangered species, we also extrapolate our results to provide a tentative estimate of the total population size in shelf waters of the eastern Bering Sea. This gives a point estimate of 25 animals (CV 29.1%; 95% confidence interval 13–47), which agrees well with what little is known for this species. We discuss the assumptions underlying the method. Obtaining more reliable values requires a larger sample of randomly located hydrophones, together with improved estimates of call rate. KEY WORDS: Bering Sea · Point transects · Distance sampling · Normal mode propagation · Abundance estimation · Acoustic recording package · ARP · High frequency acoustic package · HARP Full text in pdf format Erratum NextCite this article as: Marques TA, Munger L, Thomas L, Wiggins S, Hildebrand JA (2011) Estimating North Pacific right whale Eubalaena japonica density using passive acoustic cue counting. Endang Species Res 13:163-172. https://doi.org/10.3354/esr00325 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 13, No. 3. Online publication date: March 09, 2011 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2011 Inter-Research.

Parrotfishes (family Scaridae) are an important component of coral reef ecosystems, and this key functional group plays a major role in algae removal and bioerosion of reef substrate. They are also heavily fished in many locations, which may lead to ecosystem-wide impacts such as increased algal cover. In the State of Hawaii, parrotfish management is a priority for marine resource managers, with an ongoing need for accurate population monitoring that is currently addressed by diver-based visual surveys. However, parrotfishes are highly mobile and somewhat skittish around SCUBA divers, particularly in areas where fishing pressure is high. Because parrotfishes produce frequent audible scraping and crunching sounds associated with feeding, passive acoustic monitoring (PAM) can provide information on parrotfish occurrence without requiring the invasive presence of divers. Here, we present results from analyses of parrotfish foraging sounds in long-term acoustic recordings from 10 shallow reef locations throughout the Hawaiian Archipelago dating back to 2006. Parrotfish sounds are compared spatially across a fishing pressure gradient, from heavily fished areas in the main Hawaiian Islands to protected waters within the Papahānaumokuākea Marine National Monument (Northwestern Hawaiian Islands). Results from PAM are compared when possible with data from adjacent visual censuses conducted by divers.