About
44
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Introduction
My work is focused on understanding the role and recovery of large whales throughout the Southern Ocean. In addition to Antarctic research, I also provide scientific advice on the effects of man-made underwater noise on marine mammals around Australia and Antarctica.
My main acoustic research tools in the Southern Ocean are sonobuoys and autonomous moored-acoustic recording devices. I use sonobuoys to locate and track blue and fin whales in real-time during vessel based surveys. Moored acoustic recorders provide continuous sound recordings for an entire year for each deployment at each recording site. Both of these tools are especially useful for learning about blue, fin, and sperm whales, since these species are very vocal, but are otherwise not frequently encountered.
Additional affiliations
November 2010 - May 2011
March 2006 - March 2010
Position
- PhD Student
Description
- PhD Thesis: Acoustically derived growth rates and diving behaviour of sperm whales in Kaikoura, NZ
May 2003 - August 2005
Publications
Publications (44)
Since 2001, hundreds of thousands of hours of underwater acoustic recordings have been made throughout the Southern Ocean south of 60° S. Detailed analysis of the occurrence of marine mammal sounds in these circumpolar recordings could provide novel insights into their ecology, but manual inspection of the entirety of all recordings would be prohib...
An automated algorithm for passive acoustic detection of blue whale D-calls was developed based on established deep learning methods for image recognition via the DenseNet architecture. The detector was trained on annotated acoustic recordings from the Antarctic, and performance of the detector was assessed by calculating precision and recall using...
During three surveys in the austral summers of 2013, 2015, 2019, data on Antarctic blue whale blow rates, dive times, swim speeds, and broadscale movements were collected using video photogrammetric tracking and intra-voyage photo-identification. A total of 24.4 hours of video observations were suitable for blow interval or movement analysis. Simil...
The seasonal occupancy and diel behaviour of sperm whales (Physeter macrocephalus) was investigated using data from long-term acoustic recorders deployed off east Antarctica. An automated method for investigating acoustic presence of sperm whales was developed, characterised, and applied to multi-year acoustic datasets at three locations. Instead o...
We model the presence of rare Antarctic blue whales (Balaenoptera musculus intermedia) in relation to the swarm characteristics of their main prey species, Antarctic krill (Euphausia superba). A combination of visual observations and recent advances in passive acoustic technology were used to locate Antarctic blue whales, whilst simultaneously usin...
This study presents evidence of diel patterns in fin whale (Balaenoptera physalus) 20 Hz acoustic presence in Eastern Antarctic waters. Passive acoustic recordings were collected at four sites in Eastern Antarctica from 2013 to 2019. A generalized linear model fitted by a generalized estimating equation was used to test the hypothesis that fin whal...
Satellite tags were deployed on two Antarctic blue whales ( Balaenoptera musculus intermedia ) in the east Antarctic sector of the Southern Ocean as part of the International Whaling Commission’s Southern Ocean Research Partnership initiative. The satellite tracks generated are the first and currently, the only, satellite telemetry data that exist...
The fin whale is listed as globally vulnerable, with ongoing threats to their population, yet little is known about the distribution and movements of the Southern Hemisphere sub-species, Balaenoptera physalus quoyi. This study assesses fin whale distribution in the Southern Hemisphere analysing acoustic recordings from 15 locations in Antarctic and...
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ABSTRACT
An automated algorithm for passive acoustic detection of blue whale D-calls is developed based on established deep learning methods for image recognition via the DenseNet architecture. Koogu—an open-source Python package—was used for developing the detector. The detector was trained on annotated acoustic recordings from th...
The source levels, SL, of Antarctic blue and fin whale calls were estimated using acoustic recordings collected from directional sonobuoys deployed during an Antarctic voyage in 2019. Antarctic blue whale call types included stereotyped song and downswept frequency-modulated calls, often respectively referred to as Z-calls (comprising song units-A,...
Crabeater seals are circumpolar, ice-dependent seals that produce distinct vocalizations during the breeding season. This study provides the first description of the acoustic repertoire of the crabeater seal in East Antarctica, using data from a stationary hydrophone at 1.8 km depth in the Southern Kerguelen Plateau region in 2014–2015. Two call ty...
Southern right whale vocalizations were recorded concurrently with visual observations off the sub-Antarctic Island of South Georgia, and the characteristics of these calls were described. Calls were also compared to those of humpback whales at South Georgia, to determine how the two species might reliably be distinguished acoustically. The souther...
Since 2001, hundreds of thousands of hours of underwater acoustic recordings have been made throughout the Southern Ocean south of 60° S. Detailed analysis of the occurrence of marine mammal sounds in these circumpolar recordings could provide novel insights into their ecology, but manual inspection of the entirety of all recordings would be prohib...
Blue whales Balaenoptera musculus at South Georgia were heavily exploited during 20 th century industrial whaling, to the point of local near-extirpation. Although legal whaling for blue whales ceased in the 1960s, and there were indications of blue whale recovery across the wider Southern Ocean area, blue whales were seldom seen in South Georgia w...
Around 176500 whales were killed in the sub-Antarctic waters off South Georgia (South Atlantic) between 1904 and 1965. In recent decades, whales have once again become summer visitors, with the southern right whale (SRW) the most commonly reported species until 2011. Here, we assess the distribution, temporal pattern, health status and likely prey...
Over 170,000 whales were killed in the sub-Antarctic waters of South Georgia (Islas Georgias del Sur, SG, South Atlantic) from 1904 to 1965. In recent decades, whales are regular summer visitors, with the southern right whale (Eubalaena australis) and humpback whale (Megaptera novaeangliea) most commonly reported. A 23-day cetacean survey was condu...
aboard the RV Investigator. The voyage departed from and returned to Hobart, Tasma-nia, Australia, and conducted most marine science operations in the area between 60°S-67°S and 138°E-152°E. As part of the multidisciplinary research programme, a passive acoustic survey for marine mammals was undertaken for the duration of the voyage, with the main...
The Protocol on Environmental Protection of the Antarctic Treaty stipulates that the protection of the Antarctic environment and associated ecosystems be fundamentally considered in the planning and conducting of all activities in the Antarctic Treaty area. One of the key pollutants created by human activities in the Antarctic is noise, which is pr...
A maximum likelihood method is presented for estimating drift direction and speed of a directional sonobuoy given the deployment location and a time series of acoustic bearings to a sound source at known position. The viability of this method is demonstrated by applying it to two real-world scenarios: (1) during a calibration trial where buoys were...
The 2016/17 Antarctic Circumnavigation Expedition (ACE), conducted by the newly-created Swiss Polar Institute, took place from 20 December 2016 – 19 March 2017, aboard the Russian icebreaker RV Akademik Treshnikov. Scientists from the Australian Antarctic Division conducted acoustic monitoring for marine mammals during Legs 2 and 3 of the ACE voyag...
Eight blue whales were photo-identified from coastal waters around New Zealand in 2015: seven from the South Island and one from Raoul Island (of the Kermadec Islands). Our collection of New Zealand blue whale photo-identifications now totals 38 individuals (27 left sides, 25 right sides). The 2015 photos were compared to one another and to 31 iden...
Directional frequency analysis and recording (DIFAR) sonobuoys can allow real-time acoustic localization of baleen whales for underwater tracking and remote sensing, but limited availability of hardware and software has prevented wider usage. These software limitations were addressed by developing a module in the open-source software PAMGuard. A ca...
Blue whales are infrequently reported from New Zealand and their taxonomic status is unclear. Here we present new information on the residency, external morphology, and habitat use of blue whales encountered in New Zealand waters. Thirty-one blue whales were photo-identified around the North and South Islands of New Zealand from 2004-2014 in seven...
Since its near extirpation during the period of industrial whaling in the early and mid 20th century, the once common Antarctic blue whale Balaenoptera musculus intermedia remains extremely rare. While annual systematic surveys around Antarctica from 1978 to 2009 recorded only 216 visual encounters of this species, their loud and distinctive calls...
Simultaneous sightings and acoustic detections of sei whales (Balaenoptera borealis) are scarce, and there are few published data describing their vocalizations.
Analysis of recordings from directional frequency analysis and recording sonobuoys in the presence of sei whales in the Southern Ocean in March 2013 identified both downsweep and upsweep c...
The song of Antarctic blue whales (Balaenoptera musculus intermedia) comprises repeated, stereotyped, low-frequency calls. Measurements of these calls from recordings spanning many years have revealed a long-term linear decline as well as an intra-annual pattern in tonal frequency. While a number of hypotheses for this long-term decline have been i...
Collecting enough data to obtain reasonable abundance estimates of whales is often difficult, particularly when studying rare species. Passive acoustics can be used to detect whale sounds and are increasingly used to estimate whale abundance. Much of the existing effort centres on the use of acoustics to estimate abundance directly, e.g. analysing...
Passive acoustic localisation of blue whales has been a key component of Antarctic blue whale research, and is likely to become a key tool for future research conducted as a part of the Southern Ocean Research Partnership's Antarctic Blue Whale Project. This document presents methods to measure the accuracy and precision of a sonobuoy-based localis...
Previous underwater recordings made in New Zealand have identified a complex sequence of low frequency sounds that have been attributed to blue whales based on similarity to blue whale songs in other areas. Recordings of sounds with these characteristics were made opportunistically during the Southern Ocean Research Partnership's recent Antarctic B...
Observations are presented of the vocal behavior and three dimensional (3D) underwater movements of sperm whales measured with a passive acoustic array off the coast of Kaikoura, New Zealand. Visual observations and vocal behaviors of whales were used to divide dive tracks into different phases, and depths and movements of whales are reported for e...
A non-invasive acoustic method for measuring the growth of sperm whales was developed based on estimating the length of individuals by measuring the inter-pulse interval (IPI) of their clicks. Most prior knowledge of growth in male sperm whales has come from from fitting growth curves to length data gained from whaling. Recordings made at Kaikoura,...
The Southern Ocean Research Partnership (SORP) is an international research program initiated within the International Whaling Commission (IWC) in 2009 to promote collaborative cetacean research, develop nov el research techniques, and conduct non-lethal research on whales in the Southern Ocean (CHILDERHOUSE 2009). One of the original research proj...
Grenadiers Macrourus spp. are the main bycatch species in the exploratory longline fishery for toothfish Dissostichus spp. in the Ross Sea, Antarctica. Ongoing monitoring tools are needed to assess stock status of grenadiers in the Ross Sea and to ensure ecological relationships are maintained. There may be potential to use fisheries acoustic metho...
Passive acoustic tracking of blue whales has been proposed as a key component in a strategy to obtain a circumpolar abundance for Antarctic blue whale as proposed in a project of the IWC Southern Ocean Research Partnership. While a theoretical basis for passive tracking of blue whales has been demonstrated, there are substantial differences between...
Sperm whales (Physeter macrocephalus) emit short, broadband clicks which often include multiple pulses. The time interval between these pulses [inter-pulse interval (IPI)] represents the two-way time for a pulse to travel between the air sacs located at either end of the sperm whale's head. The IPI therefore, is a proxy of head length which, using...
A passive sonar array designed for tracking diving sperm whales in three dimensions from a single small vessel is presented, and the advantages and limitations of operating this array from a 6 m boat are described. The system consists of four free floating buoys, each with a hydrophone, built-in recorder, and global positioning system receiver (GPS...
The purpose of this study was to measure both middle ear stiffness and basilar membrane stiffness for the bottlenose dolphin ( Tursiops truncatus ) and compare these results with similar measures in other mammalian species. It was found that the point stiffness of the bottlenose dolphin basilar membrane has a gradient from 20 N/m near the base to 1...
Previous research on the cetacean auditory system has consisted mostly of behavioral studies on a limited number of species. Little quantitative physiologic data exists on cetacean hearing. The frequency range of hearing varies greatly across different mammalian species. Differences among species correlate with differences in the middle-ear transfe...
The purpose of this study was to measure both middle ear stiffness and basilar membrane stiffness for the bottlenose dolphin (Tursiops truncatus) and compare these results with similar measures in other mammalian species. It was found that the point stiffness of the bottlenose dolphin basilar membrane has a gradient from 20 N/m near the base to 1.5...
