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Fin Whale Continuous Frequentation Of St Lawrence Habitats Detected From Multi Year Passive Acoustic Monitoring Pam
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Book Synopsis Fin Whale Continuous Frequentation of St. Lawrence Habitats Detected from Multi-year Passive Acoustic Monitoring (PAM) by : Nathalie Roy
Download or read book Fin Whale Continuous Frequentation of St. Lawrence Habitats Detected from Multi-year Passive Acoustic Monitoring (PAM) written by Nathalie Roy and published by . This book was released on 2019 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Blue Whale Continuous Frequentations of St. Lawrence Habitats from Multi-year PAM Series by : Yvan Simard
Download or read book Blue Whale Continuous Frequentations of St. Lawrence Habitats from Multi-year PAM Series written by Yvan Simard and published by . This book was released on 2016 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Blue Whale Continuous Frequentations of St. Lawrence Habitats from Multi-year PAM Series by :
Download or read book Blue Whale Continuous Frequentations of St. Lawrence Habitats from Multi-year PAM Series written by and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 'The endangered northwest Atlantic blue whale is a regular visitor of the Gulf of St. Lawrence where they feed upon aggregated krill. As part of the population recovery plan, a passive acoustic monitoring (PAM) observatory was set up to track the space-time patterns of blue whale use of this northwest Atlantic marginal sea from their species-specific calls from 2010 to 2015. The PAM network included 4 regular multi-year stations and 2 1-year stations covering the two Gulf entrances and the expected excursion routes. The most frequent "A-type" infrasonic call was tracked with a dedicated algorithm while the rarer and less energetic low frequency D-call was manually detected from the spectrograms, aided by an energy detector. During the monitoring period, the blue whale was present year-round in the southern Gulf of St. Lawrence, and almost year-round in the Lower Estuary. They were not detected at the northeastern station near Belle Isle Strait. No clear lag between the appearance and disappearance at the stations along the inland route from the Atlantic was observed, which does not plea in favour of a seasonal synchronous migration. The co-occurrence of detections at all sites during a large part of the annual cycle indicate a dispersed population over numerous sites of interest in the studied area, which includes periods of arrival and departures as indicated by fluctuations in call occurrence. Results clearly show that blue whales occupy the whole region, not only during summer and fall, but year-round"--Abstract (p. iv)
Book Synopsis Performance Study of Passive Acoustic Systems for Detecting North Atlantic Right Whales in Seaways by : Cédric Gervaise
Download or read book Performance Study of Passive Acoustic Systems for Detecting North Atlantic Right Whales in Seaways written by Cédric Gervaise and published by . This book was released on 2019 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Optimal Passive Acoustic Systems for Real-time Detection and Localization of North Atlantic Right Whales in Their Feeding Ground Off Gaspé in the Gulf of St. Lawrence by : Cédric Gervaise
Download or read book Optimal Passive Acoustic Systems for Real-time Detection and Localization of North Atlantic Right Whales in Their Feeding Ground Off Gaspé in the Gulf of St. Lawrence written by Cédric Gervaise and published by . This book was released on 2019 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Blue and Fin Whale Acoustics and Ecology Off Antarctic Peninsula by : Ana Širović
Download or read book Blue and Fin Whale Acoustics and Ecology Off Antarctic Peninsula written by Ana Širović and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Blue whales (Balaenoptera musculus) and fin whales (B. physalus) in the Southern Ocean were subjects of extensive whaling industry during the twentieth century. Their current population numbers remain low, making population monitoring using traditional visual surveys difficult. Both blue and fin whales produce low frequency, regularly repeated calls and are suitable for acoustic monitoring. Eight continuously recording acoustic recorders were deployed off the Western Antarctic Peninsula (WAP) between March 2001 and February 2003. Ranges to calling blue and fin whales were calculated using hyperbolic localization and multipath arrivals up to the distances of 200 and 56 km., respectively. Calls of both species had high intensity, blue whales calls had the average source level 189±3dB re: 1[mu]Pa at 1 meter and the average fin whale call source level was 189±4dB re: 1[mu]Pa at 1 meter. Automatic call detection methods were used for analysis of calling blue and fin whale seasonal presence and habitat preferences. Blue whale calls were detected year round (on average 177 days/year) with peak calling in March and April and a secondary peak in October and November. Fin whale calling rates were seasonal with calls detected between February and June (on average 51 days/year) with a peak in May. During the entire deployment period, detected calls from both species showed negative correlation with sea ice concentrations. Baleen whale sounds were recorded during multiple cruises off the Antarctic Peninsula using sonobuoys. Recordings from two fall cruises off the WAP were used for analyses of habitat preferences of calling blue and fin whales. The presence of calling blue whales was positively correlated with bottom depth and sea surface temperature and negatively correlated with krill biomass in the top 100 meters and abundance of the rest of the zooplankton at depth (101-300 meters). Locations of fin whale calls were associated with a deep trough area and high Chl-a concentrations. Distribution of baleen whale calls recorded in the Scotia Sea (east of the Antarctic Peninsula) indicated that fin whales occur in open water, and blue, southern right (Eubalaena australis), minke (B. bonaerensis), and humpback whales (Megaptera novaeangliae) occur near islands or close to the ice edge.
Book Synopsis The Development of Automated Detection Techniques for Passive Acoustic Monitoring as a Tool for Studying Beaked Whale Distribution and Habitat Preferences in the California Current Ecosystem by :
Download or read book The Development of Automated Detection Techniques for Passive Acoustic Monitoring as a Tool for Studying Beaked Whale Distribution and Habitat Preferences in the California Current Ecosystem written by and published by . This book was released on 2012 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, passive acoustic survey methods have become increasingly important in marine mammal population and ecosystem studies. Passive acoustic monitoring has been progressively combined with traditional visual survey techniques during line transect surveys for marine mammals. The objectives of this research were to test available automated detection methods for passive acoustic monitoring and integrate the best available method into standard marine mammal monitoring protocols for ship based surveys. Specifically, there were three overarching goals: 1) develop, test, and compare algorithms for automated classification of beaked whale signals; 2) employ and test techniques for beaked whale detection at sea; and, 3) use information from automated beaked whale detections to create the first acoustic based habitat models for beaked whale species and compare these with visual-based models for the same region. The goal of the first chapter was to evaluate the performance and utility of PAMGUARD 1.0 Core software for use in automated detection of marine mammal acoustic signals during towed array surveys. Three different detector configurations of PAMGUARD were compared. These automated detection algorithms were evaluated by comparing them to the results of manual detections made by an experienced bio-acoustician (author TMY). This study provides the first detailed comparisons of PAMGUARD automated detection algorithms to manual detection methods. The results of these comparisons clearly illustrate the utility of automated detection methods for odontocete species. Results of this work showed that the majority of whistles and click events can be reliably detected using PAMGUARD software. The second chapter moves beyond automated detection to examine and test automated classification algorithms for beaked whale species. Beaked whales are notoriously elusive and difficult to study, especially using visual survey methods. However, due to recent advances in passive acoustic monitoring techniques, beaked whales are now more effectively detected acoustically than visually during vessel-based (e.g. line-transect) surveys. Beaked whales signals can be discriminated from those of other cetaceans by the unique characteristics of their echolocation clicks (e.g. duration>175 [lower case mu]s, center frequencies between 30-40 kHz, inter-click intervals between 0.2-0.4 sec and frequency upsweeps). Furthermore, these same characteristics make these signals ideal candidates for testing automated detection and classification algorithms. There are several different beaked whale automated detectors currently available for use. However, no comparative analysis of detectors exists. Therefore, comparison between studies and datasets is difficult. The purpose the second chapter was to test, validate, and compare algorithms for detection of beaked whales in acoustic line-transect survey data. Six different detection algorithms (XBAT, Ishmael, PAMGUARD, ERMA, GMM and FMCD) were evaluated and compared. Detection trials were run on three sample days of towed-hydrophone array recordings collected by NOAA Southwest Fisheries Science Center (SWFSC) during which were confirmed visual sightings of beaked whales (Ziphius cavirostris and Mesoplodon peruvianus). Detections also were compared to human verified acoustic detections for a subset of these data. In order to measure the probabilities of false detection, each detector was also run on three sample recordings containing clicks from another species: Risso's dolphin (Grampus griseus). Qualitative and quantitative comparisons and the detection performance of the different algorithms are discussed. Using data collected at sea from the PAMGUARD classifier developed in Chapter 2 it was possible to measure the clicks from visually verified Baird's beaked whale encounters and use this data to develop classifiers that could discriminate Baird's beaked whales from other beaked whale species in future work. Echolocation clicks from Baird's beaked whales, Berardius bairdii, were recorded during combined visual and acoustic shipboard surveys of cetacean populations in the California Current Ecosystem (CCE) and with autonomous, long-term recorders at four different sites in the Southern California Bight (SCB). The preliminary measurement of the visually validated Baird's beaked whale echolocation signals recorded from the ship-based towed array were used as a basis for identifying Baird's signals in the seafloor-mounted autonomous recorder data. Echolocation signals were segregated into four subsets based on a Gaussian Mixture Model with five mixtures over the peak frequency distribution to describe variability in the signal measurements. The median peak frequency for each of the four subsets measured from towed array and [long-term seafloor data] was at approximately 9 kHz [9 kHz], 19 kHz [16 kHz], 24 kHz [25 kHz], and 35 kHz [43 kHz]. Two distinct signal types were found, one being a beaked whale-like frequency modulated (FM) pulse, the other being a dolphin-like broadband click. Median center frequency ranged over all subsets and both recording situations from 17 to 36 kHz, -10 dB bandwidth from 6 to 13 kHz, and Teager-energy duration from 260 to 570 [lower case mu]s. The median inter-pulse interval was 0.23 seconds. The description of Baird's echolocation signals provided here will allow for studies of their distribution and abundance using towed array data without associated visual sightings and from autonomous seafloor hydrophones. The passive acoustic detection algorithms for beaked whales developed using data from Chapters 2 and 3 were field tested during a three year period to test the reliability of acoustic beaked whale monitoring techniques and to use these methods to describe beaked whale habitat in the SCB. In 2009 and 2010, PAM methods using towed hydrophone arrays were tested. These methods proved highly effective for real-time detection of beaked whales in the SCB and were subsequently implemented in 2011 to successfully detect and track beaked whales during the ongoing Southern California Behavioral Response Study (SOCAL-BRS). The three year field effort has resulted in (1) the successful classification and tracking of Cuvier's (Ziphius cavirostris), Baird's (Berardius bairdii) and unidentified Mesoplodon beaked whale species and (2) the identification of areas of previously unknown beaked whale habitat use. Thus, providing a better understanding of the relationship between beaked whale occurrence and preferred habitat on a relatively small spatial scale. These findings will provide information for more effective management and conservation of beaked whales. The final step in this research was to utilize the passive acoustic detection techniques developed herin to predictively model beaked whale habitat use and preferences in the CCE. To date beaked whale habitat models have been limited in utility due primarily to the small samples of visual observations available to inform the models. This chapter uses a multifaceted approach to model beaked whale encounter rates in the CCE. Beaked whale acoustic encounters are utilized to inform Generalized Additive Models (GAMs) of encounter rate for beaked whales in the CCE and compare these to visual based models. Acoustic and visual based models were independently developed for a small beaked whale group and Baird's beaked whales. Species distributions were modeled using a combination of fixed spatial features (depth, slope, aspect, and distance to the 2000m isobaths) and variable oceanographic variables (i.e., SST, SSS, logC, and MLD). Two models were evaluated for visual and acoustic encounters, one that also included Beaufort sea state as a predictor variable in addition to those listed and one that did not include Beaufort sea state. The visual and acoustic models differed markedly for both small beaked whales and Baird's beaked whale in the predictor variables retained in the best fit models and the regions of high encounter rate prediction. The visual models that included Beaufort sea state as a predictor variable retained this variable in the best fit resulting models. Acoustic models for the small beaked whales retained fixed spatial features of depth, slope, aspect and distance to the 2000 m isobaths as predictors in the best fit model, whereas only mixed layer depth was retained as a predictor in the best fit Baird's beaked whale acoustic model. The visual best fit model retained aspect and SST as predictor variables for small beaked whales and retained all predictor variables in the best fit Baird's beaked whale model. Differences in all models for Baird's beaked whale compared to the small beaked whales indicate that Baird's beaked whale habitat preferences may be distinctive from other beaked whale species. This work promotes current understanding of beaked whale distribution and habitat that can be used to inform beaked whale management and conservation efforts. This study has demonstrated the feasibility of using acoustic data to inform habitat models. Future work will benefit from utilizing acoustic data to inform habitat models for beaked whales and likely for other cryptic species as well. The culmination of this research has advanced techniques used in passive acoustic monitoring during towed array marine mammal surveys. The ability to efficiently detect and classify beaked whales using a towed hydrophone array represents a significant contribution to the field of marine mammal science. This work promotes current understanding of beaked whale distribution and habitat preferences and the highlights the role of behavioral and physiological processes in habitat selection.
Book Synopsis Fin Whale Distribution in the Indian and Equatorial Pacific Oceans in Support of Passive Acoustic Density Estimation by : Julia Vernon
Download or read book Fin Whale Distribution in the Indian and Equatorial Pacific Oceans in Support of Passive Acoustic Density Estimation written by Julia Vernon and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of passive acoustic monitoring in population density estimation of marine mammals is a developing capability, providing an efficient and cost-effective alternative to visual surveys. However, this method of density estimation introduces new challenges. Passive acoustic density estimation incorporates several variables, including the number of animal vocalizations detected over a period of time, the probability of detecting vocalizations in a given area, and the vocalization rate of the species of interest. Automatic detectors are needed to quickly and effectively detect vocalizing animals in a large data set. Such detectors need to be assessed for effectiveness, accounting for inefficiencies and quantifying the probability of detecting a vocalization by the species of interest. Another challenge that arises is uncertainty in the geographic distribution of individuals. Estimating distribution through consideration of the horizontal azimuths of vocalizing animals reduces bias introduced by the assumption that on average, animals are uniformly distributed around the sensors.Low-frequency ambient noise data (
Book Synopsis Characteristics of Fin Whale Vocalizations Recorded on Instruments in the Northeast Pacific Ocean by : Maria Michelle Josephine Weirathmueller
Download or read book Characteristics of Fin Whale Vocalizations Recorded on Instruments in the Northeast Pacific Ocean written by Maria Michelle Josephine Weirathmueller and published by . This book was released on 2016 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis focuses on fin whale vocalizations recorded on ocean bottom seismometers (OBSs) in the Northeast Pacific Ocean, using data collected between 2003 and 2013. OBSs are a valuable, and largely untapped resource for the passive acoustic monitoring of large baleen whales. This dissertation is divided into three parts, each of which uses the recordings of fin whale vocalizations to better understand their calling behaviors and distributions. The first study describes the development of a technique to extract source levels of fin whale vocalizations from OBS recordings. Source levels were estimated using data collected on a network of eight OBSs in the Northeast Pacific Ocean. The acoustic pressure levels measured at the instruments were adjusted for the propagation path between the calling whales and the instruments using the call location and estimating losses along the acoustic travel path. A total of 1241 calls were used to estimate an average source level of 189 +/-5.8 dB re 1uPa @ 1m. This variability is largely attributed to uncertainties in the horizontal and vertical position of the fin whale at the time of each call, and the effect of these uncertainties on subsequent calculations. The second study describes a semi-automated method for obtaining horizontal ranges to vocalizing fin whales using the timing and relative amplitude of multipath arrivals. A matched filter is used to detect fin whale calls and pick the relative times and amplitudes of multipath arrivals. Ray-based propagation models are used to predict multipath times and amplitudes as function of range. Because the direct and first multiple arrivals are not always observed, three hypotheses for the paths of the observed arrivals are considered; the solution is the hypothesis and range that optimizes the fit to the data. Ray-theoretical amplitudes are not accurate and solutions are improved by determining amplitudes from the observations using a bootstrap method. Data from ocean bottom seismometers at two locations are used to assess the method: one on the Juan de Fuca Ridge, a bathymetrically complex mid-ocean ridge environment, and the other at a flat sedimented location in the Cascadia Basin. At both sites, the method is reliable up to ~4 km range which is sufficient to enable estimates of call density. The third study explores spatial and temporal trends in fin whale calling patterns. The frequency and inter-pulse interval of fin whale 20 Hz vocalizations were observed over 10 years from 2003-2013 on bottom mounted hydrophones and OBSs in the northeast Pacific Ocean. The instrument locations extended from 40°N and 130°W to 125°W with water depths ranging from 1500-4000 m. The inter-pulse interval (IPI) of fin whale song sequences was observed to increase at a rate of 0.59 seconds/year over the decade of observation. During the same time period, peak frequency decreased at a rate of 0.16 Hz/year. Two primary call patterns were observed. During the earlier years, the more commonly observed pattern had a single frequency and single IPI. In later years, a doublet pattern emerged, with two dominant frequencies and two IPIs. Many call sequences in the intervening years appeared to represent a transitional state between the two patterns. The overall trend was consistent across the entire geographical span, although some regional differences exist.
Book Synopsis Passive Acoustic Monitoring of North Atlantic Fin Whales with the Use of Ocean Bottom Seismic Arrays by : Laura Gilling
Download or read book Passive Acoustic Monitoring of North Atlantic Fin Whales with the Use of Ocean Bottom Seismic Arrays written by Laura Gilling and published by . This book was released on 2016 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :Canada. Environment Canada Publisher :Sainte-Foy, Québec : St. Lawrence Vision 2000 ISBN 13 :9780662332503 Total Pages :1 pages Book Rating :4.3/5 (325 download)
Book Synopsis Monitoring the State of the St. Lawrence River : Beluga Whale Population of the Estuary by : Canada. Environment Canada
Download or read book Monitoring the State of the St. Lawrence River : Beluga Whale Population of the Estuary written by Canada. Environment Canada and published by Sainte-Foy, Québec : St. Lawrence Vision 2000. This book was released on 2002 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Singing Fin Whales Tracked Acoustically Offshore of Southern California by : Leah McLean Varga
Download or read book Singing Fin Whales Tracked Acoustically Offshore of Southern California written by Leah McLean Varga and published by . This book was released on 2016 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fin whales (Balaenoptera physalus) produce a stereotyped low frequency call (15-30 Hz) that can be detected at great range and is considered song when produced in a repeated pattern. These calls, referred to as 20 Hz calls, were localized and animals were tracked using a kilometer-scale array of four passive acoustic recorders deployed at approximately 800m depth, northwest of San Clemente Island in the Southern California Bight. A total of 4969 calls were localized over four continuous weeks during late fall of 2007. The average estimated source level for the localized calls was 190.9 ± 7.4 dB peak-to-peak re 1[mu]Pa2 at 1m. The majority of the calls in these data were in the form of a doublet song pattern, with average inter-pulse intervals (IPI) 13s and 18s. The tracks were the first to be recorded for singing fin whales transiting alone using passive acoustic monitoring. Acoustic tracking of fin whales provides insight into the ecology and behavior of the species. Estimating call source levels help future predictions of how these whales are impacted by anthropogenic noise. Call source level, along with calling behavior, provide important parameters required for population density estimation. Furthermore, studying fin whale song patterns may aid in distinguishing different subpopulations.
Book Synopsis Patterns of Seasonal Occurrence of Sympatric Killer Whale Lineages in Waters Off Southern Vancouver Island and Washington State, as Determined by Passive Acoustic Monitoring by : Amalis Riera
Download or read book Patterns of Seasonal Occurrence of Sympatric Killer Whale Lineages in Waters Off Southern Vancouver Island and Washington State, as Determined by Passive Acoustic Monitoring written by Amalis Riera and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Killer whales inhabiting coastal waters of the northeastern Pacific are listed under the Canadian Species at Risk Act, which requires the identification of critical habitats for the recovery of their populations. Little is known about their distribution during the winter and what areas are important for their survival during these months. Passive acoustic monitoring is a valuable complementary method to traditional visual and photographic surveys although it has seldom been used to study killer whales and there are limitations in practice. There is a need to develop tools and protocols to maximize the efficiency of such studies. In this thesis, long-term acoustic data collected with autonomous recorders were analyzed 1) to assess the performance of two types of analysis (Manual and Long Term Spectral Averages) for detecting and identifying killer whale calls and to compare the effects of using two different duty cycles (1/3 and 2/3); and 2) to investigate the seasonal occurrence of different killer whale populations at two sites off the west coasts of Vancouver Island and Washington: Swiftsure Bank and Cape Elizabeth. Both the use of Long Term Spectral Averages and a lower duty cycle resulted in a decrease in call detection and resolution of call identification, leading to underestimations of the amount of time the whales spent at the site. A compromise between a lower resolution data processing method and a higher duty cycle (and vice-versa) is therefore suggested for future passive acoustic monitoring studies of killer whales. Killer whale calls were detected on 186 days at Swiftsure Bank and on 39 days at Cape Elizabeth. The seasonal occurrence of killer whales at Swiftsure Bank highlights its importance as a killer whale hotspot, with year-round presence of Southern Residents and British Columbia Transients, Northern Residents in spring and fall, and California Transients on rare occasions. These results support the expansion of Southern Resident's critical habitat to include Swiftsure Bank. Temporal habitat partitioning between Resident populations was observed at Cape Elizabeth, with Southern Residents detected from January through June and Northern Residents from July to September. These results show that Northern Residents use the southern parts of their range more frequently than previously thought. Both Transient populations were frequently detected throughout the year, suggesting habitat overlapping.
Book Synopsis Patterns of Fin Whale (Balaenoptera Physalus) Seasonality and Relative Distribution in Canadian Pacific Waters Inferred from Passive Acoustic Monitoring by : James F Pilkington
Download or read book Patterns of Fin Whale (Balaenoptera Physalus) Seasonality and Relative Distribution in Canadian Pacific Waters Inferred from Passive Acoustic Monitoring written by James F Pilkington and published by . This book was released on 2018 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Site Specific Passive Acoustic Detection and Densities of Humpback Whale Calls Off the Coast of California by : Tyler Adam Helble
Download or read book Site Specific Passive Acoustic Detection and Densities of Humpback Whale Calls Off the Coast of California written by Tyler Adam Helble and published by . This book was released on 2013 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Passive acoustic monitoring of marine mammal calls is an increasingly important method for assessing population numbers, distribution, and behavior. Automated methods are needed to aid in the analyses of the recorded data. When a mammal vocalizes in the marine environment, the received signal is a filtered version of the original waveform emitted by the marine mammal. The waveform is reduced in amplitude and distorted due to propagation effects that are influenced by the bathymetry and environment. It is important to account for these effects to determine a site-specific probability of detection for marine mammal calls in a given study area. A knowledge of that probability function over a range of environmental and ocean noise conditions allows vocalization statistics from recordings of single, fixed, omnidirectional sensors to be compared across sensors and at the same sensor over time with less bias and uncertainty in the results than direct comparison of the raw statistics. This dissertation focuses on both the development of new tools needed to automatically detect humpback whale vocalizations from single-fixed omnidirectional sensors as well as the determination of the site-specific probability of detection for monitoring sites off the coast of California. Using these tools, detected humpback calls are "calibrated" for environmental properties using the site-specific probability of detection values, and presented as call densities (calls per square kilometer per time). A two-year monitoring effort using these calibrated call densities reveals important biological and ecological information on migrating humpback whales off the coast of California. Call density trends are compared between the monitoring sites and at the same monitoring site over time. Call densities also are compared to several natural and human-influenced variables including season, time of day, lunar illumination, and ocean noise. The results reveal substantial differences in call densities between the two sites which were not noticeable using uncorrected (raw) call counts. Additionally, a Lombard effect was observed for humpback whale vocalizations in response to increasing ocean noise. The results presented in this thesis develop techniques to accurately measure marine mammal abundances from passive acoustic sensors.
Book Synopsis Temporal and Spatial Distributions of Baleen Whales in Central New Zealand, Based on Passive Acoustic Monitoring by : Victoria Warren
Download or read book Temporal and Spatial Distributions of Baleen Whales in Central New Zealand, Based on Passive Acoustic Monitoring written by Victoria Warren and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effective management of wild animal populations relies on an understanding of their spatio-temporal distributions, and how they overlap with threats. Passive acoustic monitoring (PAM) is a non-invasive method to investigate the distribution of free-ranging species that reliably produce sound, and soundscape analysis enables an integrated approach whereby vocal species are sampled concurrently with ambient environmental information. Physical and acoustic overlaps between soundscape contributors can highlight potential interactions and threats. Worldwide, the distributions of baleen whales have proven difficult to study due to logistical constraints imposed by their offshore distributions and limited surface time. However, many baleen whales reliably produce stereotyped sound, and are therefore suitable to study acoustically. In the western South Pacific, weather and sea conditions have particularly constrained understanding of baleen whale distributions. Here, four acoustic recorders were deployed in the marine environment around central New Zealand to elucidate the spatio-temporal distributions of " ̃data deficient' baleen whales that frequent the region. The recorded data featured notable acoustic contributions from several baleen whale species. Seismic surveys, shipping and earthquakes overlapped in time, space, and frequency with baleen whale vocalisations, highlighting potential risks and stressors in New Zealand waters. An acoustic approach enabled pygmy blue whales (PBWs) to be distinguished from " ̃critically endangered' Antarctic blue whales (ABWs). PBWs were detected in the South Taranaki Bight (STB) throughout recording periods, and detection area modelling demonstrated that an aggregation of PBWs likely occurs in the STB; an industrial area. ABWs and humpback whales migrated through central New Zealand seasonally, with both species generally travelling north through Cook Strait and the STB, rather than along the east coast of the North Island. ABWs were also detected during their breeding season. Based on song content, the humpback whales were likely migrating to breed in New Caledonia, or East Australia, and song transmission may occur between the two breeding populations in the New Zealand migratory corridor. This study highlights the utility of PAM to map the distributions of free-ranging species and potential stressors, which can be challenging to study via alternative methods. Such data are essential to underpin conservation and management decisions.
Book Synopsis Advancing Baleen Whale Acoustic and Habitat Monitoring in the Northwest Atlantic by : Hansen Dalmasse Johnson
Download or read book Advancing Baleen Whale Acoustic and Habitat Monitoring in the Northwest Atlantic written by Hansen Dalmasse Johnson and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Baleen whales of the Northwest Atlantic live in an urbanized ocean. They attempt a slow recovery from commercial whaling amid threats from the infrastructure, pollution, and shifting environmental baseline associated with human exploitation of the natural world. Current risk mitigation strategies all rely on a comprehensive knowledge of whale distribution, which is difficult to obtain given limited resources, a vast ocean, and the cryptic nature of whale behaviour. This thesis strives to advance baleen whale monitoring with passive acoustics, habitat ecology, and new technology. Chapters 2 and 3 use several different approaches to improve the quality and interpretation of data derived from passive acoustic monitoring. Chapter 4 introduces "WhaleMap", a tool for rapidly collating and displaying whale survey results to inform dynamic research and management activities. Chapters 5 and 6 characterize associations among baleen whale species and their oceanographic habitat to identify priority areas and times for increased monitoring and/or risk mitigation. Particular focus is paid to the North Atlantic right whale because their dire conservation status motivates much of this work, but in many cases the results apply to other baleen whale species. It is our hope that the monitoring advancements put forward by this thesis lead directly to improved conservation outcomes that help preserve these species for generations to come.
