Anthropogenic Noise Sources Research Articles

Responses to sound in three Centrarchid species: Do heterospecific interactions change behavior?

Due to the increasing prevalence and variety of underwater anthropogenic noise sources, and the growing human population, anthropogenic noise has the potential to negatively impact aquatic organisms. With this growing threat, the question of how fishes respond to this stressor in their natural environments becomes more urgent. The current study used behavioral trials with bluegill sunfish Lepomis macrochirus, pumpkinseed sunfish Lepomis gibbosus, and rock bass Ambloplites rupestris, both in isolation and in a heterospecific trial, to determine how behaviors indicative of stress were influenced by interspecific interactions when exposed to recordings of pure tones and boat motors. Regardless of social context, all three species experienced an increase in fin beats per second, an increase in time spent at the bottom of the pen, and a decrease in time spent swimming when exposed to boat noise. Fishes in heterospecific trials experienced more fin beats per second and spent less time swimming, but there was no significant difference when comparing time spent at the bottom of pen with fish in individual trials. Our findings of behavioral changes when exposed to acoustic stimuli, in two social contexts, allow for a deeper understanding of interspecific effects and provide insight into how varied field studies can be useful in studying fish behavior when encountering acoustic stressors.

Characterization of maritime traffic noise in two areas of the Mediterranean

One of the objectives of the European JPI Oceans DeuteroNoise project is to investigate the soundscapes within different sea basins. Measurement campaigns, including the recording of raw noise data (wave files), have been carried out in the Venice Lagoon, in the North Adriatic and on Barcelona shore. In this work we will present the first results. The data acquired were processed to obtain the characteristic spectrum and noise levels; subsequently the velocity of the particles will be acquired and analysed. The analysis of the recorded data involves the design of a taxonomy of anthropogenic noise sources, e.g. large ships, small boats or any other existing noise source. The recorded data were labelled with these sources, describing their main audio characteristics (spectral distribution, temporal evolution, etc.) for their characterization and future blind identification. Throughout the measurement period, ship and route data were acquired using AIS (Automatic Identification System) and Vessel Monitoring System (VMS) in the measurement sites. The preliminary analysis and labelling, together with ship and route data, will allow the reproduction of acoustic environments of anthropogenic origin in laboratories and the creation of acoustic maps of the basins investigated using commercial software.

Refocusing aquatic noise: Shifting from single to combined anthropogenic pressures

Aquatic animals (invertebrates, fishes, and marine mammals) are encountering an increasing array of underwater anthropogenic noises that can disrupt and even harm ecosystems as well as the lives of individuals and populations. Sources of anthropogenic noise include, but are not limited to, shipping, offshore exploration and production for fossil fuels, and the construction and operation of wind farms. Because of the continuing increase in anthropogenic noise, research on its potential effects on aquatic animals has intensified over the past two decades. However, a major under-explored issue is that noise is only one type of anthropogenic pressure acting (often simultaneously) on animals. Indeed, multiple simultaneous anthropogenic pressures are likely to affect how aquatic animals respond to each of the individual stimuli. Moreover, animal responses may be very different in the presence of multiple pressures as compared to when there is only a single anthropogenic source. We suggest refocusing of aquatic noise so that research prioritizes studies that deal with the interaction of noise with other anthropogenic pressures on aquatic life. At the same time, we call for an acceleration of studies providing baseline data for cumulative risk studies, such as monitoring of ambient noise around the globe.

Follow the Trace: Becoming a Seismo-Detective with a Campus-Based Raspberry Shake Seismometer

Abstract Seismic signals, whether caused by earthquakes, other natural phenomena, or artificial noise sources, have specific characteristics in the time and frequency domains that contain crucial information reflecting their source. The analysis of seismic time series is an essential part of every seismology-oriented study program. Enabling students to work with data collected from their own campus, including signals from both anthropogenic and natural seismic sources, can provide vivid, practical examples to make abstract concepts communicated in classes more concrete and relevant. Data from research-grade broadband seismometers enable us to record time series of vibrations at a broad range of frequencies; however, these sensors are costly and are often deployed in remote places. Participation in the Raspberry Shake citizen science network enables seismology educators to record seismic signals on our own campuses and use these recordings in our classrooms and for public outreach. Yale University installed a Raspberry Shake three-component, low-cost seismometer in the Earth and Planetary Sciences department building in Summer 2022, enabling the detection of local, regional, and teleseismic earthquakes, microseismic noise, and anthropogenic noise sources from building construction, an explosive event in a steam tunnel, and general building use. Here, we discuss and illustrate the use of data from our Raspberry Shake in outreach and education activities at Yale. In particular, we highlight a series of ObsPy-based exercises that will be used in courses taught in our department, including our upper-level Introduction to Seismology course and our undergraduate classes on Natural Disasters and Forensic Geoscience.

Vessels and aircraft are chronic sources of anthropogenic noise in coastal marine and terrestrial soundscapes on Long Island, New York

Passive acoustic data collected during 2020 and 2021 were used to monitor changes in both terrestrial and underwater soundscapes, as well as human activity from aircraft and vessels. Passive acoustic data were collected at two artificial reefs south of Long Island, as well as along ocean beaches in Southampton, NY. At the artificial reefs, vessel noise was recorded more frequently during 2020 than in 2021. Commercial vessels and multi-user charter fishing vessels were more abundant during 2020. Peaks in power spectral density occurred at 60, 90 and 120 Hz in 2020 and 2021, which are frequencies consistent with noise generated by commercial vessels, suggesting that vessels are a significant contributor to the soundscape of the artificial reefs. In the terrestrial environment, noise generated by aircraft was more common during 2021. Peaks in power spectral density were measured around 160 and 290 Hz at one of the ocean beach sites. These frequencies are consistent with noise generated by aircraft. This study documents the chronic extent of anthropogenic noise in both the underwater and terrestrial environments of Long Island, NY, as well as quantifies the occurrence of various noise sources in these habitats.

Noise source localization using deep learning

Summary Ambient noise source localization is of great significance for estimating seismic noise source distribution, understanding source mechanisms and imaging subsurface structures. The commonly used methods for source localization, such as the matched field processing and the full-waveform inversion, are time-consuming and not applicable for time-lapse monitoring of the noise source distribution. We propose an efficient alternative of using deep learning for noise source localization. In the neural network, the input data are noise cross-correlation functions and the output are matrices containing the information of noise source distribution. It is assumed that the subsurface structure is a horizontally layered earth model and the model parameters are known. A wavefield superposition method is employed to efficiently simulate ambient noise data with quantities of local noise sources labelled as training datasets. We use a weighted binary cross-entropy loss function to address the prediction inaccuracy caused by a sparse label matrix during training. The proposed deep learning framework is validated by synthetic tests and two field data examples. The successful applications to locate an anthropogenic noise source and a carbon dioxide (CO2) degassing area demonstrate the accuracy and efficiency of the proposed deep learning method for noise source localization, which has great potential for monitoring the changes of the noise source distribution in a survey area.

Acoustic detection and classification of all-terrain vehicles and automobiles in pennsylvania state parks

The preservation of today’s natural environment is more important than ever before; with the encroachment of civilization, protected areas are necessary. This protection must go beyond just saving wildlife but also protecting natural soundscapes for visitors to experience “dispersed low-density outdoor recreation.” However, some visitors use the wilds for motorized recreation such as Off-Road Vehicles, All Terrain Vehicles, and Side-by-Side Vehicles producing elevated levels of noise which could impact the other visitors. In order to determine how the protected areas were used, listening stations were placed at high-traffic areas to monitor the soundscape for one summer. This dataset was analyzed to understand the number and impact of anthropogenic noise sources. This research develops a training dataset that could be implemented with supervised machine-learning models to automate event detection and classification.

Erratum to Reply to “Comment on ‘Sources of Long-Range Anthropogenic Noise in Southern California and Implications for Tectonic Tremor Detection’ by Asaf Inbal, Tudor Cristea-Platon, Jean-Paul Ampuero, Gregor Hillers, Duncan Agnew, and Susan E. Hough” by Allie Hutchison, Yijian Zhou, and Abhijit Ghosh

<i>Erratum to</i> Reply to “Comment on ‘Sources of Long-Range Anthropogenic Noise in Southern California and Implications for Tectonic Tremor Detection’ by Asaf Inbal, Tudor Cristea-Platon, Jean-Paul Ampuero, Gregor Hillers, Duncan Agnew, and Susan E. Hough” by Allie Hutchison, Yijian Zhou, and Abhijit Ghosh

Georeferenced Analysis of Urban Nightlife and Noise Based on Mobile Phone Data

Urban environments are characterized by a complex soundscape that varies across different periods and geographical zones. This paper presents a novel approach for analyzing nocturnal urban noise patterns and identifying distinct zones using mobile phone data. Traditional noise-monitoring methods often require specialized equipment and are limited in scope. Our methodology involves gathering audio recordings from city sensors and localization data from mobile phones placed in urban areas over extended periods with a focus on nighttime, when noise profiles shift significantly. By leveraging machine learning techniques, the developed system processes the audio data to extract noise features indicative of different sound sources and intensities. These features are correlated with geographic location data to create comprehensive city noise maps during nighttime hours. Furthermore, this work employs clustering algorithms to identify distinct noise zones within the urban landscape, characterized by their unique noise signatures, reflecting the mix of anthropogenic and environmental noise sources. Our results demonstrate the effectiveness of using mobile phone data for nocturnal noise analysis and zone identification. The derived noise maps and zones identification provide insights into noise pollution patterns and offer valuable information for policymakers, urban planners, and public health officials to make informed decisions about noise mitigation efforts and urban development.

Temporal patterns in the soundscape of the port area in an urban estuary

Soundscape ecology, facilitated by the collection of environmental sounds, enables the determination of the area used by specific species, estimation of population abundance, verification of habitat health, and assistance in management and monitoring processes. Estuaries are key environments in the life cycle of many species. As coastal ecosystems, they face potential impacts by human activities. This study aims to characterize the soundscape of the Patos Lagoon estuary (PLE), Brazil, examining its temporal and seasonal variations. Additionally, it seeks to investigate the influence of temperature and salinity on sound pressure levels (SPL) across three different frequency bands throughout the year. For data collection, two autonomous devices - a SoundTrap digital recorder and an F-POD sampler - were used. The data collection spanned from September 2020 to August 2021 and covered one consecutive week per season. The analysis of audio files was performed manually using Raven software. Sound emissions by Lahille's bottlenose dolphin (Tursiops truncatus gephyreus) and fish were observed throughout the sampling period, with peak detections occurring during the summer and spring, respectively. Boat noise was detected throughout the year but more intensely in the summer. Generalized linear models (GLMs) revealed that, for the three SPL frequency bands, the season significantly influenced the composition of the PLE soundscape, with positive fluctuations in the warmer seasons (summer > spring > autumn > winter). Salinity, in turn, showed a slightly negative relationship with the SPL values in the three models, suggesting a decrease in frequencies with increasing salinity. Our results also indicate that the low-frequency SPL, originating mostly from various sources of anthropogenic noise, constitutes the main component of the PLE soundscape. In conclusion, our study provides novel insights into the temporal patterns of the soundscape in an urban estuary, including biotic and anthropogenic sounds, and their relationships with selected environmental variables.

Fine-scale spatial variability of marine acoustic environment corresponds with habitat utilization of Indo-Pacific humpback dolphins in Hong Kong waters

Acoustic properties of the underwater environment are important in maintaining biological processes of various marine organisms. However, with the increasing level of underwater noise in the global ocean, there is a growing need to better understand how marine animals use soundscape cues in their habitat selection. Indo-Pacific humpback dolphins (Sousa chinensis) inhabiting the Pearl River Estuary, southeast China, live in one of world’s most developed and noisiest coastal environment and are subjected to many sources of anthropogenic noise. To investigate whether spatial variability of underwater soundscape corresponds with their habitat utilization, we collected daytime underwater recordings in western Hong Kong waters from mid-2016 to mid-2018, and quantified the spatial pattern of marine acoustic environment and its differing characteristics in a fine spatial scale. We developed a framework of soundscape information retrieval to investigate spectral features that may facilitate identification of dolphins’ core habitats. Our findings reveal that a spectral feature, which peaks at 2 kHz, is a reliable predictor of humpback dolphin core habitat. Further modelling of spatial and seasonal variations of underwater soundscape demonstrates that the relative strength of this spectral feature is positively correlated with the sighting rates of humpback dolphins throughout the year. Although the source of the 2 kHz feature remains unknown, it is likely associated with humpback dolphins’ prey. We suggest that underwater acoustic environment represents an important component in evaluating the quality and suitability of coastal habitats for the daily needs of this threatened dolphin species. Local and regional conservation authorities should include habitat-specific baseline soundscape data when developing conservation management strategies.

Using behavioural response experiments to measure humpback whale hearing in noise

Currently, there are no direct data on mysticete hearing in noise. Available data comes from anatomical modelling, the assumption they can hear their own sounds, and studies on the effects of various sources of anthropogenic noise on their behavior. This study used a behavioral response study design to quantify humpback whale hearing in natural ocean noise. Tonal signals, ranging from 250 Hz to 16kHz, were used as the stimuli, and a change in humpback group behavior indicated the whales heard the signal. Individual whale and group behavior were quantified using a combination of land-based tracking data of groups and tag data deployed on individual whales to record fine-scale 3D movement underwater. The signal-to-noise ratio was estimated at the initial response position of the group or whale, assuming this was the level at which they first detected the tone in noise. Results confirm that humpback whales responded to signals in noise at detection levels comparable to other marine mammals and that their ability to hear signals in noise at higher frequencies is better than expected. This provides empirical data on hearing in a mysticete which can be used to better predict the acoustic impacts of anthropogenic noise on marine mammals.

Montreal soundscapes during the COVID-19 pandemic: A spatial analysis of noise complaints and residents’ surveys

Abstract Public health measures during the COVID-19 pandemic provided researchers with a quasi-experimental situation to examine what happens when anthropogenic noise sources (e.g., traffic) are greatly reduced. This article combines noise-related calls to Montreal’s 311 service (29,891 calls from 2014 to 2022) with original survey data from 240 residents collected in 2020 after the lockdown and the summer reopening. The spatial analysis of the calls revealed that, across all pandemic phases, noise complaints increased with population density, the proportion of low-income residents, and the proportion of greenspace. However, the change in the spatial distribution of noise-related calls due to the pandemic measures is positively associated with the proportions of residential and greenspace land use. That is, areas with higher proportions of residential land use and greenspace experienced the greatest increase in noise-related calls. The analysis of the survey revealed that the sounds of traffic and construction decreased during both the lockdown and the subsequent reopening, while the sounds of the neighborhood and nature increased. However, the decreased traffic noise in the downtown core also allowed for the emergence of noise from the heating, ventilation and air conditioning systems in the area. We discuss these results considering the interest in reducing noise levels in cities.

Reply to “Comment on ‘Sources of Long-Range Anthropogenic Noise in Southern California and Implications for Tectonic Tremor Detection’ by Asaf Inbal, Tudor Cristea-Platon, Jean-Paul Ampuero, Gregor Hillers, Duncan Agnew, and Susan E. Hough” by Allie Hutchison, Yijian Zhou, and Abhijit Ghosh

Reply| May 17, 2023 Reply to “Comment on ‘Sources of Long‐Range Anthropogenic Noise in Southern California and Implications for Tectonic Tremor Detection’ by Asaf Inbal, Tudor Cristea‐Platon, Jean‐Paul Ampuero, Gregor Hillers, Duncan Agnew, and Susan E. Hough” by Allie Hutchison, Yijian Zhou, and Abhijit Ghosh Asaf Inbal; Asaf Inbal * 1Department of Geophysics, Tel Aviv University, Tel Aviv, Israel *Corresponding author: asafinbal@tauex.tau.ac.il https://orcid.org/0000-0001-8848-7279 Search for other works by this author on: GSW Google Scholar Tudor Cristea‐Platon; Tudor Cristea‐Platon 2Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts, U.S.A. https://orcid.org/0000-0001-8268-4693 Search for other works by this author on: GSW Google Scholar Jean‐Paul Ampuero; Jean‐Paul Ampuero 3Université Côte d’Azur, IRD, CNRS, Observatoire de la Côte d’Azur, Géoazur, Sophia Antipolis, France https://orcid.org/0000-0002-4827-7987 Search for other works by this author on: GSW Google Scholar Gregor Hillers; Gregor Hillers 4Institute of Seismology, University of Helsinki, Helsinki, Finland https://orcid.org/0000-0003-2341-1892 Search for other works by this author on: GSW Google Scholar Duncan Agnew Duncan Agnew 5Scripps Institution of Oceanography, University of California, San Diego, California, U.S.A. https://orcid.org/0000-0002-2360-7783 Search for other works by this author on: GSW Google Scholar Author and Article Information Asaf Inbal https://orcid.org/0000-0001-8848-7279 * 1Department of Geophysics, Tel Aviv University, Tel Aviv, Israel Tudor Cristea‐Platon https://orcid.org/0000-0001-8268-4693 2Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts, U.S.A. Jean‐Paul Ampuero https://orcid.org/0000-0002-4827-7987 3Université Côte d’Azur, IRD, CNRS, Observatoire de la Côte d’Azur, Géoazur, Sophia Antipolis, France Gregor Hillers https://orcid.org/0000-0003-2341-1892 4Institute of Seismology, University of Helsinki, Helsinki, Finland Duncan Agnew https://orcid.org/0000-0002-2360-7783 5Scripps Institution of Oceanography, University of California, San Diego, California, U.S.A. *Corresponding author: asafinbal@tauex.tau.ac.il Publisher: Seismological Society of America First Online: 17 May 2023 Online ISSN: 1943-3573 Print ISSN: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2023) https://doi.org/10.1785/0120200007 Article history First Online: 17 May 2023 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation Asaf Inbal, Tudor Cristea‐Platon, Jean‐Paul Ampuero, Gregor Hillers, Duncan Agnew; Reply to “Comment on ‘Sources of Long‐Range Anthropogenic Noise in Southern California and Implications for Tectonic Tremor Detection’ by Asaf Inbal, Tudor Cristea‐Platon, Jean‐Paul Ampuero, Gregor Hillers, Duncan Agnew, and Susan E. Hough” by Allie Hutchison, Yijian Zhou, and Abhijit Ghosh. Bulletin of the Seismological Society of America 2023; doi: https://doi.org/10.1785/0120200007 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Tectonic tremor is associated with seismic signals in the 2–8 Hz frequency band whose durations are up to several minutes, and that can be correlated between stations separated by distances of up to a hundred kilometers or so. Since its discovery in Japan by Obara (2002), spontaneous and dynamically triggered (i.e., induced by transient seismic waves) tectonic tremor has been observed in many subduction zone environments (e.g., Gomberg et al., 2008; Peng and Chao, 2008; Peng et al., 2009; Rubinstein et al., 2009; Fry et al., 2011). Outside subduction zones,... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Comment on “Sources of Long-Range Anthropogenic Noise in Southern California and Implications for Tectonic Tremor Detection” by Asaf Inbal, Tudor Cristea-Platon, Jean-Paul Ampuero, Gregor Hillers, Duncan Agnew, and Susan E. Hough

Article Commentary| May 17, 2023 Comment on “Sources of Long‐Range Anthropogenic Noise in Southern California and Implications for Tectonic Tremor Detection” by Asaf Inbal, Tudor Cristea‐Platon, Jean‐Paul Ampuero, Gregor Hillers, Duncan Agnew, and Susan E. Hough Allie Hutchison; Allie Hutchison 1University of California, Riverside, Riverside, California, U.S.A. https://orcid.org/0000-0001-9350-7975 Search for other works by this author on: GSW Google Scholar Yijian Zhou; Yijian Zhou 1University of California, Riverside, Riverside, California, U.S.A. https://orcid.org/0000-0002-7205-1769 Search for other works by this author on: GSW Google Scholar Abhijit Ghosh Abhijit Ghosh * 1University of California, Riverside, Riverside, California, U.S.A. *Corresponding author: aghosh.earth@gmail.com https://orcid.org/0000-0002-0557-2839 Search for other works by this author on: GSW Google Scholar Author and Article Information Allie Hutchison https://orcid.org/0000-0001-9350-7975 1University of California, Riverside, Riverside, California, U.S.A. Yijian Zhou https://orcid.org/0000-0002-7205-1769 1University of California, Riverside, Riverside, California, U.S.A. Abhijit Ghosh https://orcid.org/0000-0002-0557-2839 * 1University of California, Riverside, Riverside, California, U.S.A. *Corresponding author: aghosh.earth@gmail.com Publisher: Seismological Society of America First Online: 17 May 2023 Online ISSN: 1943-3573 Print ISSN: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2023) https://doi.org/10.1785/0120190171 Article history First Online: 17 May 2023 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation Allie Hutchison, Yijian Zhou, Abhijit Ghosh; Comment on “Sources of Long‐Range Anthropogenic Noise in Southern California and Implications for Tectonic Tremor Detection” by Asaf Inbal, Tudor Cristea‐Platon, Jean‐Paul Ampuero, Gregor Hillers, Duncan Agnew, and Susan E. Hough. Bulletin of the Seismological Society of America 2023; doi: https://doi.org/10.1785/0120190171 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Inbal et al. (2018; hereafter, I18) dismissed all the tremor events found in Hutchison and Ghosh (2017; hereafter, HG17) as noise or earthquakes. Despite these assertions, and given all of the evidence put forth at this point, we stand by the findings that these signals are tremor. Unless further evidence can be provided to definitively substantiate alternative sources, tremor is the best explanation. In HG17, we use five independent sets of evidence across multiple datasets and independent techniques including (1) multibeam backprojection (Ghosh et al., 2009, 2012), (2) envelope cross correlation (Wech and... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

SCUBA noise alters community structure and cooperation at Pederson’s cleaner shrimp cleaning stations

Recreational SCUBA diving is widespread and increasing on coral reefs worldwide. Standard open-circuit SCUBA equipment is inherently noisy and, by seeking out areas of high biodiversity, divers inadvertently expose reef communities to an intrusive source of anthropogenic noise. Currently, little is known about SCUBA noise as an acoustic stressor, and there is a general lack of empirical evidence on community-level impacts of anthropogenic noise on coral reefs. Here, we conducted a playback experiment on Caribbean reefs to investigate impacts of SCUBA noise on fish communities and interspecific cooperation at ecologically important cleaning stations of the Pederson’s cleaner shrimp Ancylomenes pedersoni. When exposed to SCUBA-noise playback, the total occurrence of fishes at the cleaning stations decreased by 7%, and the community and cleaning clientele compositions were significantly altered, with 27% and 25% of monitored species being affected, respectively. Compared with ambient-sound playback, SCUBA-noise playback resulted in clients having to wait 29% longer for cleaning initiation and receiving 43% less cleaning; however, cheating, signalling, posing and time spent cleaning were not affected by SCUBA-noise playback. Our study is the first to demonstrate experimentally that SCUBA noise can have at least some negative impacts on reef organisms, confirming it as an ecologically relevant pollutant. Moreover, by establishing acoustic disturbance as a likely mechanism for known impacts of diver presence on reef animals, we also identify a potential avenue for mitigation in these valuable ecosystems.

Anthropogenic noise events perturb acoustic communication networks

Anthropogenic noise sources impact ecological processes by altering wildlife behavior and interactions with cascading impacts on community structure. The distribution and magnitude of such noise has grown exponentially over the past century, and now inundates even remote areas. Here we investigate biological responses to prolific, anthropogenic noise sources associated with the physical presence of the source (vehicle noise and human voices) and disconnected from it (aircraft overflight). Bioacoustic responses to these noise sources were documented at 103 sites in 40 U. S. National Park units. The presence of bird sounds was noted in 10-s audio samples every 2 min, for 8 days at each site and related to the presence of human voices, vehicle noise, and aircraft noise in the same and preceding samples. Generalized additive models were used to fit smoothing splines to weight the influence of noise in past samples on the probability of detecting bird sounds in the present sample. We found that the probability of hearing birds increased immediately following noise events, and decreased about 2 h after the event. The negative effects were persistent more than 3 h after a noise event. The persistence of these responses – especially for noise from jets that were many kilometers distant – raises questions about the functional significance and ecological consequences of this altered activity, particularly in light of the widespread and diverse habitats in this study and ubiquity of the noise sources evaluated.

Behavioural responses of wild, spawning Atlantic cod (Gadus morhua L.) to seismic airgun exposure

Abstract Seismic airgun surveys to map petroleum deposits in the seabed may impact behaviour of marine animals over large distances. Understanding whether fish spawning behaviour is affected by this anthropogenic noise source is important because reproductive success may be impacted. The fine-scale behavioural responses of Atlantic cod to airgun exposure over an extended period were investigated using an acoustic telemetry positioning system on a spawning ground in Norway. During 2019 to 2021, 135 spawning cod were equipped with telemetry sensor tags and were exposed to airgun shooting during the spawning periods of 2020 and 2021, with varying received sound levels comparable to a full-scale survey at distances of 5 to &amp;gt;40 km. Cod demonstrated only weak responses to the disturbance from repeated 3-h treatment periods over 5-d, swimming on average slightly deeper during seismic exposure compared to silent control periods. This response varied between individuals. Longer-term effects of seismic exposure on swimming depth were not detected. No changes in swimming acceleration, displacement, or area use occurred. These results suggest that relatively distant seismic surveys do not substantially alter cod behaviour during the spawning period at received sound exposure levels varying between 115 and 145 dB re 1 µPa2s over a 5-d period.

Acoustic indices respond to specific marine mammal vocalizations and sources of anthropogenic noise

Using passive acoustic methods for biodiversity conservation and effective ecosystem monitoring is hindered by laborious, human-mediated processes of accurately identifying biologic and anthropogenic sounds within large datasets. Soundscape ecology provides a potential means of addressing this need through the use of automated acoustic-based biodiversity indices, which show promise in representing biodiversity in terrestrial environments. However, the direct relationship between specific underwater sounds and acoustic index measurements are largely unexplored. Using passive acoustic data collected from three broadband hydrophones within the Ocean Observatories Initiative’s cabled arrays in the Pacific northwest, we identified periods of vocalizing marine mammals and sources of anthropogenic noise. Automated calculations of seven acoustic indices were compared across biologic and anthropogenic sound type and call parameters. Although several index measurements did not vary significantly, the Acoustic Complexity Index (ACI) measurements increased in response to echolocation clicks from sperm whales (Physeter macrocephalus) and burst pulses originating from unidentified delphinid species. Measurements of the Bioacoustic Index (BI) decreased dramatically in response to sperm whale echolocation clicks, a more obvious trend when loud clicks were parsed from moderate and quiet clicks. Correlations coefficient and confidence interval values between ACI and BI measurements and call characteristics from sperm whales indicate a moderate to strong relationship, which was not found in correlations with delphinid calls. A generalized linear mixed-effect model indicated multiple species and sound types contribute significantly to the variation of several index measurements. Noise generated by passing ships consistently resulted in decreased values for the Normalized Difference Soundscape Index (NDSI) and Total Entropy (H) as compared to quiet periods and periods with vocalizing marine mammals. These findings provide information on the relationship between several acoustic indices and specific underwater sounds produced by marine mammals and anthropogenic sources. This ground-truthing endeavor expands the understanding of acoustic indices and their potential use as a tool for conservation and ecosystem health management purposes.

Acoustic monitoring to evaluate the effect of anthropogenic noise within a park

The aim of this paper is to propose the use of passive acoustic monitoring (PAM) as a non-invasive method to investigate the state of communities and ecosystems. PAM operates through the study and characterization of the soundscape of an area. One of the three components of the soundscape (beside geophony and biophony) is anthrophony, which is the collection of sounds produced by human activities. This kind of sounds can have effects on natural envi-ronments and natural population. In this study, recording instruments and sampling tech-niques have been used to acquire and collect sound data for long periods (two weeks) in a nat-ural terrestrial ecosystem (Ticino Park) which is affected by road and rail traffic noise. The analysis conducted studied the trends of the eco-acoustic indices belonging to three measure-ment sites to detect the presence of characteristic trends and to evaluate the influence of the two anthropogenic noise sources at different distances.