scholarly journals Approaches to reduce noise from ships operating in important killer whale habitats

2018 ◽  
Author(s):  
Rob Williams

Shipping is key to global trade, but is also a dominant source of anthropogenic noise in the ocean. Chronic noise from ships can affect acoustic quality of important whale habitats. Noise from ships has been identified as one of three main stressors–in addition to contaminants, and lack of Chinook salmon prey–in the recovery of the endangered southern resident killer whale (SRKW) population. Managers recognize existing noise levels as a threat to the acoustical integrity of SRKW critical habitat. There is an urgent need to identify practical ways to reduce ocean noise given projected increases in shipping in the SRKW's summertime critical habitat in the Salish Sea. We reviewed the literature to provide a qualitative description of mitigation approaches. We use an existing ship source level dataset to quantify how some mitigation approaches could readily reduce noise levels by 3–10 dB.

2018 ◽  
Author(s):  
Rob Williams ◽  
Christine Erbe ◽  
I Made Iwan Dewantama ◽  
I Gede Hendrawan

Taking advantage of a religious holiday called Nyepi that curtailed human activities for one day, we recorded acoustic noise levels for one week in shallow waters of a little-trafficked area west of Bali below the Ngurah Rai airport flight path (Figure 1). Sound is as important to many marine organisms as vision is to humans. From the song of the humpback whale to the exquisite sonar system of the killer whale, many marine vertebrates have evolved sophisticated systems for sending and receiving acoustic signals to facilitate vital life functions. Coral reef fish sing in a dawn chorus, much as songbirds do (McCauley and Cato, 2000).


2009 ◽  
Vol 87 (8) ◽  
pp. 726-733 ◽  
Author(s):  
T. A. Mooney ◽  
A. F. Pacini ◽  
P. E. Nachtigall

False killer whales ( Pseudorca crassidens (Owen, 1846)) depredate fish caught by the North Pacific pelagic longline fishery, resulting in loss of target species catch and the whales themselves becoming bycaught. This incidental take of false killer whales exceeds sustainable levels. In an effort to address a potential solution to reducing this depredation and bycatch, we tested an acoustic device designed to deter false killer whales from approaching longlines by reducing the whales’ echolocation performance capabilities. The device produced a series of complex, broadband signals (1–250 kHz) at high intensity levels (up to 182 dB). In the experiment, a trained false killer whale was asked to detect a target in the presence or absence of the acoustic device. Baseline performance capabilities were 95% correct responses. Initially, the device reduced the whale’s echolocation performance to chance levels. However, subsequent sessions demonstrated improvement in echolocation performance up to 85%. This improvement was likely a result of behaviorally adapting to the task and a decrease in the source level of the echolocation “disruptor”. The results underscore the challenges in using acoustic devices to reduce depredation and bycatch, and demonstrate the need for concern regarding anthropogenic noise levels and effects on odontocete echolocation capabilities.


2021 ◽  
Vol 200 ◽  
pp. 105479
Author(s):  
Lauren H. McWhinnie ◽  
Patrick D. O'Hara ◽  
Casey Hilliard ◽  
Nicole Le Baron ◽  
Leh Smallshaw ◽  
...  

2019 ◽  
Vol 91 (2A) ◽  
pp. 787-802
Author(s):  
Silvia Pondrelli ◽  
Francesca Di Luccio ◽  
Laura Scognamiglio ◽  
Irene Molinari ◽  
Simone Salimbeni ◽  
...  

Abstract Starting in 1988, with the installation of the first broadband (BB) instrument in Italy, the Mediterranean Very Broadband Seismographic Network (MedNet) program established a backbone network of BB stations of the highest quality in the Mediterranean Sea countries. The Mediterranean region is characterized by relevant and frequent seismicity related to its complex tectonics, due to the convergence of two major plates, Africa and Eurasia, and the involvement of other minor plates, as the Adriatic plate. Therefore, the MedNet project became a scientific research infrastructure of excellence, able to fill the gap of regional coverage when the availability of seismic BB instruments was still scarce. The main characteristics of the MedNet network are the highest quality of the seismographic instrumentation at remote sites and very low level of anthropogenic noise with stable conditions of pressure and temperature. After 30 yr of recordings, the MedNet program has proven that the early adoption of very BB instruments in selected sites have been the best choice. A large number of studies benefited from MedNet data, as seismic source computation and Earth structure reconstruction, at local and global scale. We present a concise overview of the contribution given by MedNet data in the last three decades to motivate and financially support the existence of this valuable infrastructure, and to further maintain this project.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 960-960
Author(s):  
Sara Luck ◽  
Katie Aubrecht

Abstract Nursing home facilities are responsible for providing care for some of the most vulnerable groups in society, including the elderly and those with chronic medical conditions. In times of crisis, such as COVID-19 or other pandemics, the delivery of ‘regular’ care can be significantly impacted. In relation to COVID-19, there is an insufficient supply of personal protective equipment (PPE) to care for residents, as PPE not only protects care staff but also residents. Nursing homes across the United States and Canada have also taken protective measures to maximize the safety of residents by banning visitors, stopping all group activities, and increasing infection control measures. This presentation shares a research protocol and early findings from a study investigating the impact of COVID-19 on quality of care in residential long-term care (LTC) in the Canadian province of New Brunswick. This study used a qualitative description design to explore what contributes to quality of care for residents living in long-term care, and how this could change in times of crisis from the perspective of long-term care staff. Interviews were conducted with a broad range of staff at one LTC home. A semi-structured interview guide and approach to thematic analysis was framed by a social ecological perspective, making it possible to include the individual and proximal social influences as well as community, organizations, and policy influencers. Insights gained will improve the understanding of quality of care, as well as potential barriers and facilitators to care during times of crisis.


2008 ◽  
Vol 14 (6) ◽  
pp. 571-580 ◽  
Author(s):  
Yang Zhou ◽  
Christopher Booth-Morrison ◽  
David N. Seidman

AbstractThe effects of varying the pulse energy of a picosecond laser used in the pulsed-laser atom-probe (PLAP) tomography of an as-quenched Ni-6.5 Al-9.5 Cr at.% alloy are assessed based on the quality of the mass spectra and the compositional accuracy of the technique. Compared to pulsed-voltage atom-probe tomography, PLAP tomography improves mass resolving power, decreases noise levels, and improves compositional accuracy. Experimental evidence suggests that Ni2+, Al2+, and Cr2+ ions are formed primarily by a thermally activated evaporation process, and not by post-ionization of the ions in the 1+ charge state. An analysis of the detected noise levels reveals that for properly chosen instrument parameters, there is no significant steady-state heating of the Ni-6.5 Al-9.5 Cr at.% tips during PLAP tomography.


1999 ◽  
Vol 5 (2) ◽  
pp. 147-153 ◽  
Author(s):  
Dingjun Cui ◽  
Ian A. Craighead

The requirements for a special approach for the quality assessment of small high-speed centrifugal fans are outlined and a new parameter designating the noise levels from the product in comprehensive form will be discussed and described as a criterion for such quality assessment.By applying techniques of signal processing and condition monitoring, the sources of the vibration and noise in different sections of the product can be identified, then the noise from each source from different components can be determined. Using this criterion, more aspects of the quality of the products can be assessed and suggestions to improve the quality of the products can be made. Finally, the assessment of a number ofvacuum cleaner motor/fan units available in the commercial market will be presented and compared with conventional specifications. It will be shown that the new parameter provides a more useful indication of appliance quality.


Author(s):  
Neelima S. Naik

Noise pollution in urban areas is recognized as a major environmental concern in India. The lack of infrastructure and fast paced life in major metropolitan cities of India has made the urban environment extremely crowded, busy as well as noisy and as a result the millions of people living in the major metropolitan areas are suffering from the impacts of noise pollution. Noise levels are escalating at such a rate that it has become a major threat to the quality of human lives. Direct links between noise and health have been established by research conducted over the past few decades. There are several causes for urban degradation such as population migration, environmental considerations not adequately being incorporated into master plans, uncoordinated and haphazard development, weak implementation of plans and laws and inadequate institutional competences and resource crunch. This paper discusses the causal factors, impacts and the different approaches adopted by the Central Government as well as some major State Pollution Control Boards to curb the urban noise problem and the need for looking into non-conventional solutions such as Ecocity programme to bring in visible environmental improvement.


2013 ◽  
Vol 17 (2) ◽  
pp. 174-185 ◽  
Author(s):  
R. Williams ◽  
C. W. Clark ◽  
D. Ponirakis ◽  
E. Ashe
Keyword(s):  

Author(s):  
Margret Sibylle Engel ◽  
Júlio Otávio Herrmann ◽  
Paulo Henrique Trombetta Zannin

  The acoustic quality of classrooms has a strong influence on the teaching and learning process. This interference assessed using the impulsive technique to measure the rate of speech transmission (STI), reverberation time (RT) and sound definition (D50). These are the most relevant acoustic descriptors in the assessment of classrooms, where verbal exposure is the means of communication between teachers and students. The evaluation took place in two buildings of the Federal University of Paraná (UFPR), built in the 1960s and another in 2016. The measured values ​​of STI, provided in the classrooms' actual acoustic conditions, were used as an adjustment parameter for simulations made with the software ODEON. After carrying out the measurements and simulations, the dimensioning of improvements was possible. The acoustic simulations presented suggestions to qualify the quality of the classrooms' acoustic comfort, ensuring that teaching and learning to do not suffer losses due to the physical structure of the classrooms. The measured values ​​of STI, RT and D50 show that, in the old building, except for a single classroom that preserves the original ceiling that had a high sound absorption coefficient, it has reasonable values, below the ideal for classrooms, according to the IEC 60268-16 (2011) standard. The investigation showed that the rooms with a roof replaced by a PVC covering had a sharp drop in acoustic quality. The newest building has classrooms with proper acoustic comfort conditions.


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