Research Interests:
This article presents measurements of underwater pile driving noise recorded during the construction of the duplicate Houghton Highway bridge in western Moreton Bay, Queensland. Moreton Bay is a protected marine park, a World Heritage... more
This article presents measurements of underwater pile driving noise recorded during the construction of the duplicate Houghton Highway bridge in western Moreton Bay, Queensland. Moreton Bay is a protected marine park, a World Heritage Site and a Ramsar Wetland, providing habitat for turtles, dugong, sharks, dolphins and whales, some species of which are listed as vulnerable to endangered. Pile driving noise was measured for small and large piles at various locations and ranges. Using an acoustic propagation model, a sound map was computed for Bramble Bay. Sound levels were compared to currently available information on impact thresholds. Ranges greater than those corresponding to impact thresholds were scanned for the absence of dolphins before and during pile driving in line with a monitoring and response plan.
Research Interests:
Out of concern about the impact of industrial noise on marine mammal communication, the Canadian Coast Guard initiated a project to develop quantitative techniques for determining the degree of interference between various kinds of noise... more
Out of concern about the impact of industrial noise on marine mammal communication, the Canadian Coast Guard initiated a project to develop quantitative techniques for determining the degree of interference between various kinds of noise and marine mammal calls. Particular emphasis lies in the study of icebreaker noise. During a cruise in the Arctic Ocean, vocalizations of different animals, for example seals, humpback whales, killer whales and beluga whales, were recorded as well as icebreaker related ramming noise and bubbler noise. If the icebreaker rams an ice-ridge at full speed, it might crack the ice immediately or be lifted onto the ridge and crack it due to its weight. Also the ice might withstand the ramming such that the ship is stopped with its propeller still turning at full speed. The corresponding noise is a broadband signal consisting of short bursts of high intensities. Bubbler noise is generated when a ship passes through cracked ice and uses so-called bubblers alo...
Research Interests:
A spectrogram-based technique is presented for detection of time-and-bandwidth limited broadband signals in underwater audio. The approach employs an iterative 1-dimensional variant of a 2-dimensional multi-scale blob-detection technique... more
A spectrogram-based technique is presented for detection of time-and-bandwidth limited broadband signals in underwater audio. The approach employs an iterative 1-dimensional variant of a 2-dimensional multi-scale blob-detection technique commonly used in image processing. In contrast to the referenced 2-dimensional technique subject to an inherent bias for circular features, the iterative 1-dimensional approach enables detection of features of arbitrary bandwidth and duration. The iterative nature (of processing successive frames) makes it an attractive choice for in-situ streaming-mode applications. The algorithm automatically chooses values for several parameters based on the input spectrogram's frequency bounds and hence is capable of being readily employed for a variety of applications. The technique's applications include detection of broadband signals of interest, such as Omura's whale (Balaenoptera omurai) calls, underwater earthquakes or explosions. With long-ter...
Research Interests:
Research Interests:
While in the northern hemisphere, many studies have been conducted on the vocal repertoire of long-finned pilot whales (Globicephala melas), no such study has been conducted in the southern hemisphere. Presented here, is the first study... more
While in the northern hemisphere, many studies have been conducted on the vocal repertoire of long-finned pilot whales (Globicephala melas), no such study has been conducted in the southern hemisphere. Presented here, is the first study on the vocalisations of long-finned pilot whales along the southern coast of mainland Australia. Multiple measures were taken of 2028 vocalisations recorded over five years in several locations. These vocalisations included tonal sounds with and without overtones, sounds of burst-pulse character, graded sounds, biphonations, and calls of multiple components. Vocalisations were further categorised based on spectrographic features into 18 contour classes. Altogether, vocalisations ranged from approximately 200 Hz to 25 kHz in fundamental frequency and from 0.03 s to 2.07 s in duration. These measures compared well with those from northern hemisphere pilot whales. Some call types were almost identical to northern hemisphere vocalisations, even though th...
Research Interests:
introduCtion The ocean is not a quiet place. It is naturally noisy with sounds from physical (wind, waves, rain, ice) and biological sources (whales, dolphins, fish, crustaceans etc.). Anthropogenic contribution to underwater noise has... more
introduCtion The ocean is not a quiet place. It is naturally noisy with sounds from physical (wind, waves, rain, ice) and biological sources (whales, dolphins, fish, crustaceans etc.). Anthropogenic contribution to underwater noise has increased rapidly in the past century. In some parts of the world, lowfrequency ambient noise has increased by 3.3 dB between 1950 and 2007, which was attributed to commercial shipping [1]. As ocean water conducts light very poorly but sound very well, many marine animals have evolved to rely primarily on their auditory system for orientation, communication, foraging and sensing their environment. For example, humpback whales (Megaptera novaeangliae) sing songs for hours to days. Killer whale (Orcinus orca) pods sharing the same geographic habitat have different dialects, and can be told apart from their calls. Odontocetes (toothed whales) use echolocation (active sonar) to navigate and forage. Fish and shrimp sing evening choruses. Coral larvae tune ...
Research Interests:
The Australian marine soundscape exhibits a diversity of sounds, which can be grouped into biophony, geophony and anthrophony based on their sources. Animals from tiny shrimp, to lobsters, fish and seals, to the largest animals on Earth,... more
The Australian marine soundscape exhibits a diversity of sounds, which can be grouped into biophony, geophony and anthrophony based on their sources. Animals from tiny shrimp, to lobsters, fish and seals, to the largest animals on Earth, blue whales, contribute to the Australian marine biophony. Wind, rain, surf, Antarctic ice break-up and marine earthquakes make up the geophony. Ship traffic, mineral and petroleum exploration and production, construction, defence exercises and commercial fishing add to the anthrophony. While underwater recorders have become affordable mainstream equipment, precise sound recording and analysis remain an art. Australia’s Integrated Marine Observing System (IMOS) consists of a network of oceanographic and remote sensors, including passive acoustic listening stations managed by the Centre for Marine Science & Technology, Curtin University, Perth. All of the acoustic recordings are freely available online. Long-term records up to a decade exist at some ...
: DRDC Atlantic has an ongoing research program that requires the transmission of acoustic energy in an undersea environment. Though the transmissions are generally at a relatively low level, every effort must be made to mitigate the... more
: DRDC Atlantic has an ongoing research program that requires the transmission of acoustic energy in an undersea environment. Though the transmissions are generally at a relatively low level, every effort must be made to mitigate the potential for impact on marine life. Future impact mitigation measures may include the development detection/classification capabilities for marine mammal vocalizations. The ocean environment tends to be noisy, so that the detection of noise itself is inadequate for alerting researchers of the presence of marine mammals. The "noise" must be classified as to its origin. e.g. has it been generated by a marine mammal. The objective of this study was to further DRDC's understanding of whale vocalizations with the aim of developing automatic acoustic whale detectors and identifiers.
Research Interests:
Cetaceans are iconic predators that serve as important indicators of marine ecosystem health. The Bremer Sub-Basin, south-western Australia, supports a diverse cetacean community including the largest documented aggregation of killer... more
Cetaceans are iconic predators that serve as important indicators of marine ecosystem health. The Bremer Sub-Basin, south-western Australia, supports a diverse cetacean community including the largest documented aggregation of killer whales (Orcinus orca) in Australian waters. Knowledge of cetacean distributions is critical for managing the area’s thriving ecotourism industry, yet is largely sporadic. Here we combined aerial with opportunistic ship-borne surveys during 2015–2017 to describe the occurrence of multiple cetacean species on a regional scale. We used generalised estimating equations to model variation in killer whale relative density as a function of both static and dynamic covariates, including seabed depth, slope, and chlorophyll a concentration, while accounting for autocorrelation. Encountered cetacean groups included: killer (n=177), sperm (n=69), long-finned pilot (n=29), false killer (n=2), and strap-toothed beaked (n=1) whales, as well as bottlenose (n=12) and co...
Research Interests:
Research Interests:
Bottlenose dolphins use whistles to communicate with their conspecifics and maintain group cohesion. We recorded 477 whistles of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the Fremantle Inner Harbour, Western Australia, on... more
Bottlenose dolphins use whistles to communicate with their conspecifics and maintain group cohesion. We recorded 477 whistles of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the Fremantle Inner Harbour, Western Australia, on nine occasions over a six-week period during May/June 2013. Over half (57 %) of the whistles had complex contours exhibiting at least one local extremum, while 32 % were straight upsweeps, 5 % downsweeps and 6 % constant-frequency. About 60 % of whistles occurred in trains. Fundamental frequency ranged from 1.1 to 18.4 kHz and whistle duration from 0.05 to 1.15 s. The maximum numbers of local extrema and inflection points were 7 and 9, respectively. Whistle parameters compared well to those of measurements made from other T. aduncus populations around Australia. Observed differences might be due to ambient noise rather than geographic separation.
Research Interests:
Automatically detecting animal signals in soundscape recordings is of benefit to passive acoustic monitoring programs which may be undertaken for research or conservation. Numerous algorithms exist, which are typically optimized for... more
Automatically detecting animal signals in soundscape recordings is of benefit to passive acoustic monitoring programs which may be undertaken for research or conservation. Numerous algorithms exist, which are typically optimized for certain situations (i.e., certain animal sound types and ambient noise conditions). Adding to the library of algorithms, this paper developed, tested, and compared three detectors for Omura's whale vocalizations (15-62 Hz; <15 s) in marine soundscape recordings which contained noise from other animals, wind, earthquakes, ships, and seismic surveys. All three detectors were based on processing of spectrographic representations. The specific methods were spectrogram cross-correlation, entropy computation, and spectral intensity "blob" tracing. The latter two were general-purpose detectors that were adapted for detection of Omura's whale vocalizations. Detector complexity and post-processing effort varied across the three detectors. Performance was assessed qualitatively using demonstrative examples, and quantitatively using Receiver-Operating Characteristics and Precision-Recall curves. While the results of quantitative assessment were dominated by the spectrogram cross-correlation method, qualitative assessment showed that all three detectors offered promising performance.
Research Interests:
Managing the impacts of vessel noise on marine fauna requires identifying vessel numbers, movement, behaviour, and acoustic signatures. However, coastal and inland waters are predominantly used by ‘small’ (<25 m-long) vessels, for... more
Managing the impacts of vessel noise on marine fauna requires identifying vessel numbers, movement, behaviour, and acoustic signatures. However, coastal and inland waters are predominantly used by ‘small’ (<25 m-long) vessels, for which there is a paucity of data on acoustic output. We reviewed published literature to construct a dataset (1719 datapoints) of broadband source levels (SLs) from 17 studies, for 11 ‘Vessel Types’. After consolidating recordings that had associated information on factors that may affect SL estimates, data from seven studies remained (1355 datapoints) for statistical modelling. We applied a Generalized Additive Mixed Model to assess factors (six continuous and five categorical predictor variables) contributing to reported SLs for four Vessel Types. Estimated SLs increased through ‘Electric’, ‘Skiff’, ‘Sailing’, ‘Monohull’, ‘RHIB’, ‘Catamaran’, ‘Fishing’, ‘Landing Craft’,’ Tug’, ‘Military’ to ‘Cargo’ Vessel Types, ranging between 130 and 195 dB re 1µPa ...
Underwater sound is modelled and mapped for purposes ranging from localised environmental impact assessments of individual offshore developments to large-scale marine spatial planning. As the area to be modelled increases, so does the... more
Underwater sound is modelled and mapped for purposes ranging from localised environmental impact assessments of individual offshore developments to large-scale marine spatial planning. As the area to be modelled increases, so does the computational effort. The effort is more easily handled if broken down into smaller regions that could be modelled separately and their results merged. The goal of our study was to split the Australian maritime Exclusive Economic Zone (EEZ) into a set of smaller acoustic zones, whereby each zone is characterised by a set of environmental parameters that vary more across than within zones. The environmental parameters chosen reflect the hydroacoustic (e.g., water column sound speed profile), geoacoustic (e.g., sound speeds and absorption coefficients for compressional and shear waves), and bathymetric (i.e., seafloor depth and slope) parameters that directly affect the way in which sound propagates. We present a multivariate Gaussian mixture model, modi...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Passive acoustic recording of marine noise has advanced considerably over recent years. For a long time, a lack of widely available technology limited the acquisition of long-term acoustic data sets to a small number of large, cabled... more
Passive acoustic recording of marine noise has advanced considerably over recent years. For a long time, a lack of widely available technology limited the acquisition of long-term acoustic data sets to a small number of large, cabled installations mostly restricted to military use. For other users, recordings were limited by the available technology to short snapshots of minutes to possibly days of data at a time. As technology has improved, passive acoustic monitoring has shown marine soundscapes are filled with biotic and abiotic sounds that occur on a range of often unpredictable timescales. Thus, snapshot recordings can lead to biased data. In 1999, the Centre for Marine Science and Technology, together with Australia’s Defence Science and Technology Organisation, began developing remote underwater sound recorders to increase the duration and quality of recordings. As time passed, the sound recorders were developed significantly, have been deployed over 600 times at a variety of Australian and international locations and have identified a plethora of biological, geophysical and anthropogenic sound sources. This paper presents a brief history of the recorders’ development and characteristics, some examples of the information they have provided and future direction for their next generation.
Research Interests:
Research Interests:
Human waterborne activities emit noise into the marine environment. This is of particular concern with regard to the potential impact on marine fauna such as cetaceans due to their acoustic specialisations. The Swan-Canning River system... more
Human waterborne activities emit noise into the marine environment. This is of particular concern with regard to the potential impact on marine fauna such as cetaceans due to their acoustic specialisations. The Swan-Canning River system in Western Australia is home to a resident community of Indo-Pacific bottlenose dolphins (Tursiops aduncus), but is also a site regularly used for various human activities. As underwater noise levels increasingly become considered as an indicator of habitat quality, there is a need to characterise the soundscapes of such areas with regard to their cetacean fauna. This study aimed to provide a description of a site within the river system known as “The Narrows”. Acoustic data were collected over a six-week period with an autonomous underwater acoustic recorder. These data were analysed using a combination of weekly spectrograms, power spectral density percentile plots, 1/3 octave band levels, and generalised estimating equations to identify prominent soundscape contributors and investigate temporal patterns in their occurrence. The soundscape was found to be strongly influenced by wind, snapping shrimp, and vessel traffic, with the sounds of bridge traffic, waves, fish, machinery, dolphins, and precipitation also contributing to the acoustic environment. Furthermore, three of these sound sources (boats, waves, and fish) were found to vary at a range of temporal scales. These results take a vital step in characterising the acoustic habitat of this river system, highlighting the need to consider temporal patterns when assessing the composition of underwater soundscapes.
Research Interests:
Research Interests:
As concern about anthropogenic noise and its impacts on marine fauna is increasing around the globe, data are being compared across populations, species, noise sources, geographic regions, and time. However, much of the raw and processed... more
As concern about anthropogenic noise and its impacts on marine fauna is increasing around the globe, data are being compared across populations, species, noise sources, geographic regions, and time. However, much of the raw and processed data are not comparable due to differences in measurement methodology, analysis and reporting, and a lack of metadata. Common protocols and more formal, international standards are needed to ensure the effectiveness of research, conservation, regulation and practice, and unambiguous communication of information and ideas. Developing standards takes time and effort, is largely driven by a few expert volunteers, and would benefit from stakeholders' contribution and support.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The study of marine soundscapes is becoming widespread and the amount of data collected is increasing rapidly. Data owners (typically academia, industry, government, and defense) are negotiating data sharing and generating potential for... more
The study of marine soundscapes is becoming widespread and the amount of data collected is increasing rapidly. Data owners (typically academia, industry, government, and defense) are negotiating data sharing and generating potential for data syntheses, comparative studies, analyses of trends, and large-scale and long-term acoustic ecology research. A problem is the lack of standards and commonly agreed protocols for the recording of marine soundscapes, data analysis, and reporting that make a synthesis and comparison of results difficult. We provide a brief overview of the components in a marine soundscape, the hard- and software tools for recording and analyzing marine soundscapes, and common reporting formats.
Research Interests:
A core task in endangered species conservation is identifying important habitats and managing human activities to mitigate threats. Many marine organisms, from invertebrates to fish to marine mammals, use acoustic cues to find food, avoid... more
A core task in endangered species conservation is identifying important habitats and managing human activities to mitigate threats. Many marine organisms, from invertebrates to fish to marine mammals, use acoustic cues to find food, avoid predators, choose mates, and navigate. Ocean noise can affect animal behavior and disrupt trophic linkages. Substantial potential exists for area-based management to reduce exposure of animals to chronic ocean noise. Incorporating noise into spatial planning (e.g., critical habitat designation or marine protected areas) may improve ecological integrity and promote ecological resilience to withstand additional stressors. Previous work identified areas with high ship noise requiring mitigation. This study introduces the concept of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;opportunity sites&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; - important habitats that experience low ship noise. Working with existing patterns in ocean noise and animal distribution will facilitate conservation gains while minimizing societal costs, by identifying opportunities to protect important wildlife habitats that happen to be quiet.
Research Interests:
Research Interests:
ABSTRACT The Centre for Marine Science &amp; Technology at Curtin University built and maintains the underwater acoustic recorders of Australia&#39;s Integrated Marine Observing System (IMOS; http://IMOS.org.au). Recordings have... more
ABSTRACT The Centre for Marine Science &amp; Technology at Curtin University built and maintains the underwater acoustic recorders of Australia&#39;s Integrated Marine Observing System (IMOS; http://IMOS.org.au). Recordings have been obtained at four locations (off Western Australia, Victoria, and New South Wales) since 2011. IMOS includes a multitude of oceanographic and remote sensors, contributed by various institutions, which are also responsible for data management. Data are shared and publicly available encouraging collaboration and syntheses. This study has compiled time series of weather data, tides, current data (from Acoustic Doppler Current Profilers, ADCP), and wind (from radar measurements), and established correlations with underwater noise is a series of one-third octave bands between 10 Hz and 3 kHz from the Perth Canyon. Our results further demonstrate that ocean noise in certain frequency bands can be used to estimate aspects of physical and biological oceanography.
Research Interests:
ABSTRACT The Northwest Shelf is an extensive oil and gas region off Western Australia. The Centre for Marine Science and Technology at Curtin University has recorded underwater noise in this region for 14 years on behalf of industry and... more
ABSTRACT The Northwest Shelf is an extensive oil and gas region off Western Australia. The Centre for Marine Science and Technology at Curtin University has recorded underwater noise in this region for 14 years on behalf of industry and government. Under the Collaborative Environmental Research Initiative (CERI), this data is being shared and synthesized to quantify the marine soundscape and to describe spatiotemporal variability. Automatic software analysis tools were developed to process the data. Power spectrum density percentiles were computed for all sites on a monthly basis, and compared. Distinct spectral features were identified. Factors contributing to the observed spatiotemporal variability ranged from long-term offshore oil and gas installations to fish choruses. [Work supported by Chevron Australia.].