Synchronous seasonal change in fin whale song in the North Pacific.

Fin whale (Balaenoptera physalus) song consists of down-swept pulses arranged into stereotypic sequences that can be characterized according to the interval between successive pulses. As in blue (B. musculus) and humpback whales (Megaptera novaeangliae), these song sequences may be geographically distinct and may correlate with population boundaries in some regions. We measured inter-pulse intervals of fin whale songs within year-round acoustic datasets collected between 2000 and 2006 in three regions of the eastern North Pacific: Southern California, the Bering Sea, and Hawaii. A distinctive song type that was recorded in all three regions is characterized by singlet and doublet inter-pulse intervals that increase seasonally, then annually reset to the same shorter intervals at the beginning of each season. This song type was recorded in the Bering Sea and off Southern California from September through May and off Hawaii from December through April, with the song interval generally synchronized across all monitoring locations. The broad geographic and seasonal occurrence of this particular fin whale song type may represent a single population broadly distributed throughout the eastern Pacific with no clear seasonal migratory pattern. Previous studies attempting to infer population structure of fin whales in the North Pacific using synchronous individual song samples have been unsuccessful, likely because they did not account for the seasonal lengthening in song intervals observed here

2006 progress report on acoustic and visual monitoring for cetaceans along the outer Washington Coast

An acoustic and visual monitoring effort for cetaceans was initiated within the boundaries of the proposed expansion area for the Quinault Underwater Tracking Range in July 2004. Acoustic data collection consisted of recordings at a site on the continental shelf to the west of Cape Elizabeth and another in deep water within Quinault Canyon. An analysis plan for acoustic data is included. Results for 32 visual surveys are presented as tables and charts for pinnipeds, dolphins, porpoises, and whales. Time series of vocalizations detected in acoustic recordings are presented for killer whales, white-sided dolphins, Risso's dolphins, unclassified dolphins, humpback whales, and sperm whales. Visual sightings show clear differences in locations, reflecting preferred habitats as well as providing information on seasonal occurrence of some species. Preliminary comparison of acoustic and visual data sets reveals interesting patterns. For example, humpback whales are most commonly seen in summer and fall throughout the visual survey region, yet song and feeding calls of these whales are heard almost exclusively in fall and winter. First steps in the development of a predictive habitat model for cetaceans are described. Continued visual and acoustic data collection is recommended. Brief summaries of papers given at four scientific meetings are included

BLUE WHALE VISUAL AND ACOUSTIC ENCOUNTER RATES IN THE SOUTHERN CALIFORNIA BIGHT

The relationship between blue whale (Balaenoptera musculus) visual and acoustic encounter rates was quantitatively evaluated using hourly counts of detected whales during shipboard surveys off southern California. Encounter rates were estimated using temporal, geographic, and weather variables within a generalized additive model framework. Visual encounters (2.06 animals/h, CV = 0.10) varied with subregion, Julian day, time of day, and year. Acoustic encounters of whales producing pulsed A and tonal B call sequences (song; 0.65 animals/h, CV = 0.06) varied by Julian day, survey mode (transit or stationary), and subregion, and encounters of whales producing downswept (D) calls (0.41 animals/h, CV=0.09) varied by Julian day and the number of animals seen. Inclusion of Julian day in all models reflects the seasonal occurrence of blue whales off southern California; however, the seasonal peak in visual encounters and acoustic encounters of D calling whales (July–August) was offset from the peak in acoustic encounters of singing whales (August–September). The relationship between visual and acoustic encounter rates varied regionally, with significant differences in several northern regions. The number of whales heard D calling was positively related to the number of animals seen, whereas the number of singing whales was not related to visual encounter rate

Spatio-temporal patterns of beaked whale echolocation signals in the North Pacific.

At least ten species of beaked whales inhabit the North Pacific, but little is known about their abundance, ecology, and behavior, as they are elusive and difficult to distinguish visually at sea. Six of these species produce known species-specific frequency modulated (FM) echolocation pulses: Baird's, Blainville's, Cuvier's, Deraniyagala's, Longman's, and Stejneger's beaked whales. Additionally, one described FM pulse (BWC) from Cross Seamount, Hawai'i, and three unknown FM pulse types (BW40, BW43, BW70) have been identified from almost 11 cumulative years of autonomous recordings at 24 sites throughout the North Pacific. Most sites had a dominant FM pulse type with other types being either absent or limited. There was not a strong seasonal influence on the occurrence of these signals at any site, but longer time series may reveal smaller, consistent fluctuations. Only the species producing BWC signals, detected throughout the Pacific Islands region, consistently showed a diel cycle with nocturnal foraging. By comparing stranding and sighting information with acoustic findings, we hypothesize that BWC signals are produced by ginkgo-toothed beaked whales. BW43 signal encounters were restricted to Southern California and may be produced by Perrin's beaked whale, known only from Californian waters. BW70 signals were detected in the southern Gulf of California, which is prime habitat for Pygmy beaked whales. Hubb's beaked whale may have produced the BW40 signals encountered off central and southern California; however, these signals were also recorded off Pearl and Hermes Reef and Wake Atoll, which are well south of their known range

Clicks of dwarf sperm whales (Kogia sima)

Captive acoustic recordings were approved by the Institutional Animal Care and Use Committee of the University of South Florida. Research in The Bahamas was conducted under the Department of Fisheries research permit 12A and was supported by a Royal Society University Research Fellowship to VMJ. Recordings in Guam were made under NMFS permit 15240 and were supported with funding provided by the NOAA/NMFS Pacific Islands Fisheries Science Center, and the U.S. Navy Pacific Fleet.The two species of the genus Kogia are widely distributed throughout the world's temperate and tropical oceans, but because they are small and highly cryptic, they are difficult to monitor. The acoustic signals of K. breviceps have been described previously, but the signals of K. sima have remained unknown. Here we present three recordings of K. sima, two from free-ranging animals and one from a captive setting, representing both the Atlantic Ocean and Pacific Ocean. The acoustic signals of K. sima are very similar to the signals of K. breviceps and other species that have narrow-band, high-frequency (NBHF) clicks. Free-ranging K. sima produce “usual” clicks that have mean peak and centroid frequencies of 127–129 kHz, mean −3 dB bandwidth of 10 kHz, mean −10 dB bandwidth of 16–17 kHz, and mean interclick interval of 110–164 ms. Although K. sima clicks cannot yet be distinguished from those of K. breviceps or other NBHF clicking species, our detailed description of this species' signals reveals the similarities between the two Kogia species, and thus allows for passive acoustic monitoring of the genus Kogia in regions where other NBHF species are not present.PostprintPeer reviewe

Examining distribution patterns of foraging and non-foraging sperm whales in Hawaiian waters using visual and passive acoustic data

Following the end of over a century of intensive commercial whaling in 1986, the monitoring and assessment of sperm whale populations is essential for guiding management and conservation decisions for their recovery. Species distribution models (SDMs) are a useful tool for examining and predicting cetacean distribution patterns and typically incorporate visual, ship-based observations. However, understanding sperm whale distribution and habitat use based solely on surface visual observations is challenging due to the significant amount of time sperm whales spend foraging at depth. For the endangered sperm whale population occurring in Hawaiian waters, we used visual and passive acoustic data collected during four annual NOAA marine mammal line-transect surveys and a suite of biologically relevant environmental variables to develop SDMs within a generalized additive modeling framework to study the distribution of sperm whale groups throughout the island chain. Additionally, the passive acoustic data allowed us to differentiate sperm whale groups as foraging or non-foraging based on their click types to account for differences in distribution and behavior within the archipelago. Foraging groups were predicted primarily in the northwestern region of the archipelago between Laysan Island and Pearl and Hermes Reef as well as north of Maui and Hawaiʻi in the main Hawaiian Islands. Non-foraging groups were predicted to be more uniformly distributed throughout the archipelago. Foraging whale models selected temperature at 584 m depth, surface chlorophyll, and location, while the only significant variables for non-foraging whale models included the standard deviation of sea surface height and location. Each variable provides insight into the oceanographic processes influencing prey abundance and, thus, sperm whale foraging behavior. This study furthers our understanding of the distribution patterns for the sperm whale population in Hawaiʻi and contributes methods for building SDMs with visual and passive acoustic data that may be applied to other cetacean species

Management of acoustic metadata for bioacoustics

Recent expansion in the capabilities of passive acoustic monitoring of sound-producing animals is providing expansive data sets in many locations. These long-termdata sets will allowthe investigation of questions related to the ecology of sound-producing animals on time scales ranging fromdiel and seasonal to inter-annual and decadal. Analyses of these data often span multiple analysts from various research groups over several years of effort and, as a consequence, have begun to generate large amounts of scattered acoustic metadata. It has therefore become imperative to standardize the types of metadata being generated. A critical aspect of being able to learn from such large and varied acoustic data sets is providing consistent and transparent access that can enable the integration of various analysis efforts. This is juxtaposed with the need to include new information for specific research questions that evolve over time. Hence, a method is proposed for organizing acoustic metadata that addresses many of the problems associated with the retention of metadata from large passive acoustic data sets. A structure was developed for organizing acoustic metadata in a consistent manner, specifying required and optional terms to describe acoustic information derived from a recording. A client-server database was created to implement this data representation as a networked data service that can be accessed from several programming languages. Support for data import froma wide variety of sources such as spreadsheets and databases is provided. The implementation was extended to access Internet-available data products, permitting access to a variety of environmental information types (e.g. sea surface temperature, sunrise/sunset, etc.) fromawide range of sources as if they were part of the data service. This metadata service is in use at several institutions and has been used to track and analyze millions of acoustic detections from marine mammals, fish, elephants, and anthropogenic sound sources.Publisher PDFPeer reviewe

Range and primary habitats of Hawaiian insular false killer whales: informing determination of critical habitat

The article of record as published may be found at https://dx.doi.org/10.3354/esr00435For species listed under the US Endangered Species Act, federal agencies must designate 'critical habitat', areas containing features essential to conservation and/or that may require special management considerations. In November 2010, the National Marine Fisheries Service proposed listing a small demographically isolated population of false killer whales Pseudorca crassidens in Hawai'i as endangered but has not yet proposed designating critical habitat. We assessed the population's range and heavily used habitat areas using data from 27 satellite tag deployments. Assessment of independence of individuals with temporally overlapping data indicated that data were from 22 'groups'. Further analyses were restricted to 1 individual per group. Tag data were available for periods of between 13 and 105 d (median = 40.5 d), with 8513 locations (93.4% from July-January). Analyses of photo-identification data indicated that the population is divided into 3 large associations of individuals (social clusters), with tag data from 2 of these clusters. Ranges for these 2 clusters were similar, although one used significantly deeper waters, and their high-use areas differed. A minimum convex polygon range encompassing all locations was ~82800 km2, with individuals ranging from Ni'ihau to Hawai'i Island and up to 122 km offshore. Three high-use areas were identified: (1) off the north half of Hawai'i Island, (2) north of Maui and Moloka'i and (3) southwest of Lana'i. Although this analysis provides information useful for decision-making concerning designation of critical habitat, there are likely other high-use areas that have not yet been identified due to seasonal limitations and availability of data from only 2 of the 3 main social clusters.Fieldwork was primarily funded by grants and contracts to Cascadia Research Collective from the National Marine Fisheries Service Pacific Islands Fisheries Science Center and the US Navy (N45) through the Southwest Fisheries Science Center, Woods Hole Oceano- graphic Institution, and the Naval Postgraduate School. The Wild Whale Research Foundation and Dolphin Quest provided additional support.Funded by Naval Postgraduate School.Office of Naval Research Grant N00014081120

Spatial and temporal occurrence of killer whale ecotypes off the outer coast of Washington State, USA

Three killer whale Orcinus orca ecotypes inhabit the northeastern Pacific: residents, transients, and offshores. To investigate intraspecific differences in spatial and temporal occur-rence off the outer coast of Washington State, USA, 2 long-term acoustic recorders were deployed from July 2004 to August 2013: one off the continental shelf in Quinault Canyon (QC) and the other on the shelf, off Cape Elizabeth (CE). Acoustic encounters containing pulsed calls were analyzed for call types attributable to specific ecotypes, as no calls are shared between ecotypes. Both sites showed killer whale presence year-round, although site CE had a higher number of days with en- counters overall. Transients were the most common ecotype at both sites and were encountered mainly during the spring and early summer. Residents were encountered primarily at site CE and showed potential seasonal segregation between the 2 resident communities, with northern resi- dents present mainly during summer and early fall when southern residents were not encountered. Offshore encounters were higher at site QC, with little evidence for seasonality. Spatial and temporal variability of residents and transients matches the distribution of their prey and can potentially be used for further inferences about prey preferences for different transient groups

Using line acceleration to measure false killer whale (Pseudorca crassidens) click and whistle source levels during pelagic longline depredation

False killer whales (Pseudorca crassidens) depredate pelagic longlines in offshore Hawaiian waters. On January 28, 2015 a depredation event was recorded 14m from an integrated GoPro camera, hydrophone, and accelerometer, revealing that false killer whales depredate bait and generate clicks and whistles under good visibility conditions. The act of plucking bait off a hook generated a distinctive 15 Hz line vibration. Two similar line vibrations detected at earlier times permitted the animal’s range and thus signal source levels to be estimated over a 25-min window. Peak power spectral density source levels for whistles (4–8 kHz) were estimated to be between 115 and 130 dB re 1 lPa2/Hz @ 1 m. Echolocation click source levels over 17–32 kHz bandwidth reached 205 dB re 1lPa @ 1 m pk-pk, or 190 dB re 1lPa @ 1 m (root-meansquare). Predicted detection ranges of the most intense whistles are 10 to 25 km at respective sea states of 4 and 1, with click detection ranges being 5 times smaller than whistles. These detection range analyses provide insight into how passive acoustic monitoring might be used to both quantify and avoid depredation encounters.The authors are indebted to Captain Jerry Ray and the rest of the F/V Katy Mary crew for permitting the camera gear to be deployed during their longline fishing trip. Robert Glatts designed the custom GoPro circuit board, and Will Cerf assisted with video footage analysis. This research was sponsored by Derek Orner under the Bycatch Reduction Engineering Program (BREP) at the National Oceanic and Atmospheric Administration (NOAA).Ye