Marine Mammal Observers Research Articles

Results of Transect Observations of Marine Mammals in the Tatar Strait and During Passages within Adjacent Water Areas in the Fall of 2018

Results of Transect Observations of Marine Mammals in the Tatar Strait and During Passages within Adjacent Water Areas in the Fall of 2018

The effects of seismic operations in UK waters: analysis of Marine Mammal Observer data

Sixteen years of information from observers on board seismic survey vessels in UK and adjacent waters have demonstrated the varied responses of marine mammals to seismic surveys. Most species showed some response to firing with ‘large arrays’ (airgun volume 500 cubic inches or more), but responses were less evident when "small arrays" (less than 500 cubic inches) were active. Several species/species groups responded proactively to the soft start procedure (where the level of firing is increased gradually) indicating that this can be an effective mitigation measure in reducing the risk of physiological damage. Despite the challenge in assigning ecological significance to the varied observed effects, the analyses in this study confirm that marine mammals are sensitive to noise from seismic surveys and therefore mitigation measures should continue to be applied to all seismic operations and such measures should cover all species.

Use of multibeam imaging sonar for observation of marine mammals and fish on a marine renewable energy site.

Environmental data is crucial for planning, permitting, execution and post construction monitoring of marine renewable energy projects. In harsh conditions in which marine renewable energy is harvested, integrated monitoring platforms comprising multibeam imaging sonar systems coupled with other sensors can provide multiparametric data of the marine environment surrounding marine renewable energy installations. The aim of this study was to test the possibilities of observing the occurrence of fish and marine mammals using a multibeam imaging sonar system deployed at a wave power test site. The results obtained from a ten-day data set proved the platform as suitable for long time underwater monitoring and also revealed that the occurrence of fish and marine mammals was distributed across characteristic time and space domains. Large fish [>0.4 m] frequently occurred at night-time and near the benthic zone. Small fish [<0.2 m] frequently occurred during daylight and within the pelagic zone. The occurrence of seals was periodically distributed along a daily cycle, with intervals of 1-2 hours between maxima and minima. In conclusion, the use of multibeam imaging sonar can be a reliable technique for the qualitative and quantitative observations of fish and marine mammals in general and at marine renewable energy sites specifically, including protected and economically important species.

Species density models from opportunistic citizen science data

Abstract With the advent of technology for data gathering and storage, opportunistic citizen science data are proliferating. Species distribution models (SDMs) aim to use species occurrence or abundance for ecological insights, prediction and management. We analysed a massive opportunistic dataset with over 100,000 records of incidental shipboard observations of marine mammals. Our overall goal was to create maps of species density from massive opportunistic data by using spatial regression for count data with an effort offset. We illustrate the method with two marine mammals in the Gulf of Alaska and Bering Sea. We counted the total number of animals in 11,424 hexagons based on presence‐only data. To decrease bias, we first estimated a spatial density surface for ship‐days, which was our proxy variable for effort. We used spatial considerations to create pseudo‐absences, and left some hexagons as missing values. Next, we created SDMs that used modelled effort to create pseudo‐absences, and included the effort surface as an offset in a second stage analysis of two example species, northern fur seals and Steller sea lions. For both effort and species counts, we used spatial count regression with random effects that had a multivariate normal distribution with a conditional autoregressive (CAR) covariance matrix, providing 2.5 million Markov chain Monte Carlo (MCMC) samples (1,000 were retained) from the posterior distribution. We used a novel MCMC scheme that maintained sparse precision matrices for observed and missing data when batch sampling from the multivariate normal distribution. We also used a truncated normal distribution to stabilize estimates, and used a look‐up table for sampling the autocorrelation parameter. These innovations allowed us to draw several million samples in just a few hours. From the posterior distributions of the SDMs, we computed two functions of interest. We normalized the SDMs and then applied an overall abundance estimate obtained from the literature to derive spatially explicit abundance estimates, especially within subsetted areas. We also created ‘certain hotspots’ that scaled local abundance by standard deviation and using thresholds. Hexagons with values above a threshold were deemed as hotspots with enough evidence to be certain about them.

A Case Study of Whistle Detection and Localization for Humpback Dolphins in Taiwan

In recent years, Taiwan’s government has focused on policies regarding offshore wind farming near the Indo-Pacific humpback dolphin habitat, where marine mammal observation is a critical consideration. The present research developed an algorithm called National Taiwan University Passive Acoustic Monitoring (NTU_PAM) to assist marine mammal observers (MMOs). The algorithm performs whistle detection processing and whistle localization. Whistle detection processing is based on image processing and whistle feature extraction; whistle localization is based on the time difference of arrival (TDOA) method. To test the whistle detection performance, we used the same data to compare NTU_PAM and the widely used software PAMGuard. To test whistle localization, we designed a real field experiment where a sound source projected simulated whistles, which were then recorded by several hydrophone stations. The data were analyzed to locate the moving path of the source. The results show that localization accuracy was higher when the sound source position was in the detection region composed of hydrophone stations. This paper provides a method for MMOs to conveniently observe the migration path and population dynamics of cetaceans without ecological disturbance.

Marine mammal biodiversity and rare narwhal (Monodon monoceros) observations near northern Ellesmere Island, Canada

AbstractA climate‐driven decline of sea ice has increased international interest in understanding the ecology of seldom studied high‐Arctic regions projected to retain the last remnants of summer sea ice. Arctic marine mammals are vulnerable to future environmental change due to their high dependence on sea ice. We completed aerial surveys in August 2019 to document the occurrence and location of marine mammals within the recently designated Tuvaijuittuq Marine Protected Area which acts as a last refuge for ice‐associated species. We present photographic evidence of narwhals (Monodon monoceros), Atlantic walruses (Odobenus rosmarus), bearded seals (Erignathus barbatus), and ringed seals (Pusa hispida) in Archer Fjord, northern Ellesmere Island, Nunavut, Canada (81°14′–81°49′ N). We discuss these observations in the context of historical records and more recent opportunistic sightings from the region to support the hypothesis of an expansion north of the currently accepted range of narwhal. The diversity and number of observations of marine mammals in Archer Fjord is a striking contrast to the relative scarcity of the rest of the surveyed region, with very few observations of ringed seals throughout the more northerly study area. Our observations highlight opportunities to further explore high‐latitude areas that may host unique marine mammal biodiversity in the region, including narwhal.

Numerical Modeling of the Exposure on Radiofrequency Radiation of Marine Mammal Observers During Their Shift: A Case Study

Following the standard numerical modeling approach for Electromagnetic Field (EMF) radiation exposure prediction, we intend to provide an analytical framework to Marine Mammal Observers (MMOs) for dynamic risk assessment; enhancing thus occupational health and safety awareness. The analysis is based on power levels and antenna characteristics reported by MMOs for two systems (VHF and UHF) located close to the working environment. Whilst occupational exposure limits apply for MMOs, as for the rest crew (seismic and maritime), evaluation of exposure levels against general public limits is presented as well. At present we have restricted our study to single-source radiation, as well as we did not consider any irregularities due to system malfunction. The worst-case scenario of continuous RF transmission was considered. Risk assessment indicated regions where radiation exposure is higher than the permissible limits. Uncertainty due to the operational environment is inserted in methodology using an uncertainty coefficient. A list of control measures is proposed, to support both MMO’s and Operators’ decision making.

Balancing risks of injury and disturbance to marine mammals when pile driving at offshore windfarms

Abstract1. Offshore windfarms require construction procedures that minimize impacts on protected marine mammals. Uncertainty over the efficacy of existing guidelines for mitigating near‐field injury when pile‐driving recently resulted in the development of alternative measures, which integrated the routine deployment of acoustic deterrent devices (ADD) into engineering installation procedures without prior monitoring by marine mammal observers.2. We conducted research around the installation of jacket foundations at the UK's first deep‐water offshore windfarm to address data gaps identified by regulators when consenting this new approach. Specifically, we aimed to (a) measure the relationship between noise levels and hammer energy to inform assessments of near‐field injury zones and (b) assess the efficacy of ADDs to disperse harbour porpoises from these zones.3. Distance from piling vessel had the biggest influence on received noise levels but, unexpectedly, received levels at any given distance were highest at low hammer energies. Modelling highlighted that this was because noise from pin pile installations was dominated by the strong negative relationship with pile penetration depth with only a weak positive relationship with hammer energy.4. Acoustic detections of porpoises along a gradient of ADD exposure decreased in the 3‐h following a 15‐min ADD playback, with a 50% probability of response within 21.7 km. The minimum time to the first porpoise detection after playbacks was &gt; 2 h for sites within 1 km of the playback.5. Our data suggest that the current regulatory focus on maximum hammer energies needs review, and future assessments of noise exposure should also consider foundation type. Despite higher piling noise levels than predicted, responses to ADD playback suggest mitigation was sufficiently conservative. Conversely, strong responses of porpoises to ADDs resulted in far‐field disturbance beyond that required to mitigate injury. We recommend that risks to marine mammals can be further minimized by (1) optimizing ADD source signals and/or deployment schedules to minimize broad‐scale disturbance; (2) minimizing initial hammer energies when received noise levels were highest; (3) extending the initial phase of soft start with minimum hammer energies and low blow rates.

Autonomous Deployment of Underwater Acoustic Monitoring Devices Using an Unmanned Aerial Vehicle: The Flying Hydrophone.

Unmanned aerial vehicles (UAV) are increasingly becoming a popular tool in the observation and study of marine mammals. However, the potential capabilities of these vehicles regarding autonomous operations are not being fully exploited for passive underwater acoustic monitoring in marine mammal research. This article presents results from the development of a UAV system equipped with an underwater acoustic recorder aimed at assisting with the monitoring of harbour porpoises in Special Areas of Conservation in the United Kingdom. The UAV is capable of autonomous navigation, persistent landing, take-off and automatic data acquisition at specified waypoints. The system architecture that enables autonomous UAV flight including waypoint planning and control is described. A bespoke lightweight underwater acoustic recorder (named the PorpDAQ) capable of transmitting the results of fast Fourier transforms (FFT) applied to incoming signals from a hydrophone was also designed. The system’s operation is successfully validated with a combination of outdoor experiments and indoor simulations demonstrating different UAVs capable of autonomously navigating and landing at specific waypoints while recording data in an indoor tank. Results from the recorder suggest that lightweight, relatively low-cost systems can be used in place of heavier more expensive alternatives.

Scaling the Laws of Thermal Imaging–Based Whale Detection

AbstractMarine mammals are under growing pressure as anthropogenic use of the ocean increases. Ship strikes of large whales and loud underwater sound sources including air guns for marine geophysical prospecting and naval midfrequency sonar are criticized for their possible negative effects on marine mammals. Competent authorities regularly require the implementation of mitigation measures, including vessel speed reductions or shutdown of acoustic sources if marine mammals are sighted in sensitive areas or in predefined exclusion zones around a vessel. To ensure successful mitigation, reliable at-sea detection of animals is crucial. To date, ship-based marine mammal observers are the most commonly implemented detection method; however, thermal (IR) imaging–based automatic detection systems have been used in recent years. This study evaluates thermal imaging–based automatic whale detection technology for its use across different oceans. The performance of this technology is characterized with respect to environmental conditions, and an automatic detection algorithm for whale blows is presented. The technology can detect whales in polar, temperate, and subtropical ocean regimes over distances of up to several kilometers and outperforms marine mammal observers in the number of whales detected. These results show that thermal imaging technology can be used to assist in providing protection for marine mammals against ship strike and acoustic impact across the world’s oceans.

Observations of Annual Walrus (&lt;i&gt;Odobenus rosmarus divergens&lt;/i&gt;) Migrations in the Nearshore Waters of the Chukotka Peninsula from 1990 to 2012

After the end of the commercial harvest, research regarding the Pacific walrus (Odobenus rosmarus divergens) in Russia was reduced and focused on the observation of animals at land-based haul-outs. This paper presents the long-term observations of the distribution, relative abundance, and direction of seasonal movements of walruses in the offshore waters of the Chukotka Peninsula, based on data obtained in 1990 – 2012. Observations of Pacific walruses and other marine mammals were conducted mainly from April through November, but some were conducted all year round. In some years up to 30 Native Chukotkan observers were employed at this task. Some watched from observation posts in Native villages onshore, and others from motorboats during hunting trips. These observations have shown that walruses are rare in January and February in the nearshore waters of the Chukotka Peninsula. Their numbers begin to increase in March. The northward movement of walruses begins in April, and walruses migrate from the Bering Sea to the Chukchi Sea throughout the summer months and early autumn. Based on observations from posts located directly in front of the southern Bering Strait, I conclude that 106 – 1055 walruses pass through the Bering Strait from July to September, to the northwest and north. At the haul-outs in the Gulf of Anadyr, the relative number of walruses remains stable during the summer (up to 11 000 individuals at all haul-outs in total based on observers’ estimates) and decreases only with the appearance of ice in October – November.

A field comparison of marine mammal detections via visual, acoustic, and infrared (IR) imaging methods offshore Atlantic Canada

Impulsive sounds generated during seismic surveys have elicited behavioral responses in marine mammals and could cause hearing impairment or injury. Mitigating exposure to seismic sound often relies on real-time marine mammal detection. Detection performance is influenced by detection method, environmental conditions, and observer experience. We conducted a field comparison of real-time detections made by marine mammal observers (MMOs), a rotating infrared (IR) camera, and via passive acoustic monitoring (PAM). Data were collected from a 38 m research vessel offshore Atlantic Canada. Our results indicate that overall detection rates increase when complementary methods are used. MMOs and PAM are likely the most effective combination during high seas and precipitation. PAM and IR can be used in darkness. In good visibility, MMOs with IR or PAM should increase detections. Our results illustrate the importance of addressing false positive IR detections, matching system capabilities to sea conditions/species of interest, and employing experienced observers.

Береговые наблюдения и спутниковое прослеживание миграций косаток и белух в Охотском море в летне- осенний период 2018 года

In July-August 2018, coastal observations of marine mammals were conducted at the mouth of the Tyvlinka River (Yekaterina Bay, Sakhalin Gulf) in the Sea of Okhotsk, Khabarovsk region. In total, 40 killer whale encounters were recorded, against 68 killer whale encounters during the same period in 2015. On the coastal strip from the mouth of the Tyvlinka River to Cape Litke there are three rookeries of true seals (largha and lakhtak), with a total number of about 300 individuals. During the period of field observations, two cases of killer whale attacks on seals were recorded. Satellite beacons were installed on three killer whales and on two belugas. These beacons made possible to monitor subsequent migrations of tagged animals during summer-autumn period of 2018. Two killer whales, tagged in the Akademiya Bay and the Konstantin Bay in August, remained in the area of Shantar Archipelago during the salmon run, then in late August - early September they moved to the open waters of the Okhotsk Sea to the area where fishery vessels harvested the demersal fish species. Female killer whale tagged in the Sakhalin Gulf migrated to the northern part of the Okhotsk Sea to the Shelikhova Bay and the Penzhinskaya Bay, and almost repeated in calendar dates and positions the track of another female killer whale that was tagged in the summer 2015. The average speed of killer whales ranged from 4.3 km/h to 8.6 km/h. Belugas are more attached to their habitats in the Sakhalin Gulf. One of tagged belugas remained in the Gulf of Sakhalin, the other passed through the Nevelskoy Strait in October and went into the Sea of Japan. The average speed of beluga whales was two to three times lower than in killer whales and ranged from 1.7 km/h to 2.5 km/h.

Lessons From Placing an Observer on Commercial Cargo Ships Off the U.S. West Coast: Utility as an Observation Platform and Insight Into Ship Strike Vulnerability

Ship strikes of whales are a growing concern around the world and especially along the U.S. West Coast, home to some of busiest ports in the world and where ship strikes on a number of species including blue, fin, and humpback whales have been documented. This trial program examined the feasibility, logistics, industry cooperation, and effectiveness of placing an observer on board a commercial ship. An experienced marine mammal observer went on five voyages, spanning over eight days on ships operating between U.S. West Coast ports. Daylight observations were conducted over 68hrs and covered over 1300nm as ships transited between three ports (Seattle, Oakland, and LA/Long Beach(LA/LB)). Sightings of large whales were reported on all (n=42), totaling an estimated 57 individuals that included humpback, blue, fin and beaked whales. Close encounters of large whales occurred, (on one occasion a near miss, estimated at 40m, of two humpbacks) and on another, a ship chose to alter course to avoid whale sightings in its path identified by the observer. All ships personnel cooperated and voluntarily aided in the observations even after initial skepticism by some crew about the program. While most effort on mitigating ship strikes along the U.S. West Coast has focused on shipping lanes, the vast majority of these sightings occurred outside these lanes and on the transit routes, emphasizing the need for added attention to these areas. This experiment demonstrates the effectiveness and promise of observations from ships providing critical information on whale locations at risk to ship strikes.

Development of observing dolphin population method using Small Vertical Take-off and Landing (VTOL) Unmanned Aerial System (AUV)

Indonesia has a very high diversity of Cetacean, observation with good accuracy and precision must be a priority in every observation. Several methods have been developed to help calculate the marine mammal population, one of them by using Vertical Take-off and Landing (VTOL) Unmanned Aerial System (UAS). VTOL UAS is flown at a certain height to capture photos that contain the number of individuals in a pod, while also mapping the movements and recording their behaviors. The aim of this study was to determine the ideal angle to capture the photos. Several observation angles, 30°, 60°, and 90° were tested Observations were conducted in three sites in Indonesia (Sepa Island, Thousand Islands, Kepulauan Seribu National Park (TNKS); Liang Beach, Maluku Island; and Nai Island Kei Achipelago). The results showed that the angles greatly affected the number of objects in the photograph. For example, on the Island of Sepa, at the angle 30°, 60°, and 90°, the number of dolphins obtained were 3, 9 and 14, respectively. This study did not find any object rejection during observation with VTOL UAS. This study suggests that higher angle of photograph from VTOL UAS increases the accuracy of the observation of marine mammals.

Нормативное регулирование использования и охраны морских млекопитающих в России

We discuss the main provisions of the national legislation on the use and protection of marine mammals. In the absence of a special legislative act, legal issues are regulated by the laws “On Environmental Protection”, “On the Animal World”, “On Fishery and the Conservation of Aquatic Biological Resources”, which include marine mammals in the more general legal concept of “aquatic biological resources”, this approach remains in subordi-nate legislation. The assigment of marine mammals into a separate legal category will contribute to the improvement of legal ways of their conserva-tion and regulation of marine activities that affect the habitat (shipping, wind power facilities, extraction of aquatic bioresources, oil and gas). There is a need to develop and adopt rules for veterinary and sanitary examination (in relation to wild capture species); rules for assistance, rehabilitation and re-lease into the natural habitat of marine mammals affected by anthropogenic factors; rules of detention in captivity; recommendations for the observation of whales and other marine mammals. The author’s conclusions contribute to the achievement of the UN sustainable development goals, the promotion of the concept of “Blue economy” and the conservation of marine mammals as a global natural heritage.

Performance of manned and unmanned aerial surveys to collect visual data and imagery for estimating arctic cetacean density and associated uncertainty

Manned aerial surveys have been used successfully for decades to collect data to infer cetacean distribution, density (number of whales/km2), and abundance. Unmanned aircraft systems (UAS) have potential to augment or replace some manned aerial surveys for cetaceans. We conducted a three-way comparison among visual observations made by marine mammal observers aboard a Turbo Commander aircraft; imagery autonomously collected by a Nikon D810 camera system mounted to a belly port on the Turbo Commander; and imagery collected by a similar camera system on a remotely controlled ScanEagle®UAS operated by the US Navy. Bowhead whale density estimates derived from the marine mammal observer data were higher than those from the Turbo Commander imagery; comparisons to the UAS imagery depended on survey sector and analytical method. Beluga density estimates derived from either dataset collected aboard the Turbo Commander were higher than estimates derived from the UAS imagery. Uncertainties in density estimates derived from the marine mammal observer data were lower than estimates derived from either imagery dataset due to the small sample sizes in the imagery. The visual line-transect aerial survey conducted by marine mammal observers aboard the Turbo Commander was 68.5% of the cost of the photo strip-transect survey aboard the same aircraft and 9.4% of the cost of the UAS survey.

Mitigation provisions to be implemented for marine seismic surveying in Latin America: a review based on fish and cetaceans

AB Aquatic Biology Contact the journal Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AB 26:199-216 (2017) - DOI: https://doi.org/10.3354/ab00688 REVIEW Mitigation provisions to be implemented for marine seismic surveying in Latin America: a review based on fish and cetaceans Alberto Acosta1,*, Nelsy Niño-Rodríguez1, Maria Camila Yepes1, Oliver Boisseau2 1UNESIS, Biology Department, Faculty of Science, Pontificia Universidad Javeriana, Carrera 7 No. 40-62, Bogotá, Colombia 2Marine Conservation Research International, 94 High Street, Kelvedon, Colchester CO5 9AA, UK *Corresponding author: laacosta@javeriana.edu.co ABSTRACT: Population growth and economic development in Latin America has led to an increase in seismic surveying to find new marine hydrocarbon reserves. However, most countries along the Pacific, Atlantic, and Caribbean lack the standards to minimize the impact of seismic exploration on marine organisms. We searched primary and secondary literature in major databases and consulted international authorities and oil companies to provide scientific evidence of the effects of seismic surveying on fish and cetaceans in order to propose minimum guidelines to reduce disturbance to marine organisms in Latin America. The results suggest that seismic surveys can disrupt basic life-cycle activities such as movement, communication, and feeding. Typical outcomes include sub-lethal effects such as escape behavior, habituation, temporary loss of hearing, and changes in vocalization behavior. In order to mitigate these impacts, we propose that oil companies must provide authorities with an environmental impact assessment that includes survey data, array specifications, and acoustic array properties before a hydrocarbon exploration license can be granted. Standard mitigation measures such as exclusion zones, marine mammal observers, and passive acoustic monitoring must be implemented to prevent potential adverse effects. Appropriate legislation and regulations must be designed and implemented, and environmental authorities should be privy to all activities by seismic vessels. Besides relevant regulations and continued monitoring, further investigation must be conducted to evaluate the impact of these activities on marine organisms. The adoption of these proposed minimum guidelines is highly recommended to minimize seismic surveying impact on fish and cetaceans in Latin American countries. KEY WORDS: Marine seismic exploration · Fish · Cetaceans · Acoustic · Sub-lethal impacts · Risk assessment Full text in pdf format PreviousNextCite this article as: Acosta A, Niño-Rodríguez N, Yepes MC, Boisseau O (2017) Mitigation provisions to be implemented for marine seismic surveying in Latin America: a review based on fish and cetaceans. Aquat Biol 26:199-216. https://doi.org/10.3354/ab00688 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AB Vol. 26. Online publication date: November 21, 2017 Print ISSN: 1864-7782; Online ISSN: 1864-7790 Copyright © 2017 Inter-Research.

Potential impacts of shipping noise on marine mammals in the western Canadian Arctic

As the Arctic warms and sea ice decreases, increased shipping will lead to higher ambient noise levels in the Arctic Ocean. Arctic marine mammals are vulnerable to increased noise because they use sound to survive and likely evolved in a relatively quiet soundscape. We model vessel noise propagation in the proposed western Canadian Arctic shipping corridor in order to examine impacts on marine mammals and marine protected areas (MPAs). Our model predicts that loud vessels are audible underwater when >100km away, could affect marine mammal behaviour when within 2km for icebreakers vessels, and as far as 52km for tankers. This vessel noise could have substantial impacts on marine mammals during migration and in MPAs. We suggest that locating the corridor farther north, use of marine mammal observers on vessels, and the reduction of vessel speed would help to reduce this impact.

Noise impact assessment on Indo-Pacific Humpback Dolphin in the habitat of the East Taiwan Strait during the first two pile driving activities of demonstration offshore wind farm

Foundation piles of the first two wind turbines were driven off the coast of Miaoli, Taiwan in 2016. However, that area is also the habitat of the critically endangered Eastern Taiwan Strait (ETS) population of Indo-Pacific humpback dolphin (Sousa chinensis). To assess potential noise effects from pile driving on the humpback dolphins, we collected underwater noise data during the construction and found that the sound pressure level (Lrms) at 750m was less than 180dB re 1μPa and the peak sound pressure (Lpk, flat) was less than 190 dB re 1μPa. We also presented recommendations of noise and marine mammal monitoring for future pile driving activities. It includes an exclusion zone of radius 750m from the piling location and the peak sound pressure (Lpk, flat) not to exceed 190~220 dB re 1μPa at 750 m distance, and an observation zone extends to 1500m radius where both marine mammal observers and passive acoustic monitoring are posted. [This work was sponsored by Ministry of Science and Technology of Taiwan (105-3113-E-002 -002 -CC2), Taiwan Bureau of Energy and Industrial technology Research Institution (05HZT56002), and U.S. Marine Mammal Commission’s Research and Conservation Grant.]