scholarly journals Simulated seal scarer sounds scare porpoises, but not seals: species-specific responses to 12 kHz deterrence sounds

2017 ◽  
Vol 4 (7) ◽  
pp. 170286 ◽  
Author(s):  
Lonnie Mikkelsen ◽  
Line Hermannsen ◽  
Kristian Beedholm ◽  
Peter Teglberg Madsen ◽  
Jakob Tougaard
Keyword(s):  
Marine Mammals ◽  
Peak Level ◽  
Sensitive Species ◽  
Sound Sources ◽  
Sound Exposure ◽  
Sound Levels ◽  
Harbour Seals ◽  
Key Species ◽  
Species Specific ◽  
Avoidance Reactions

Acoustic harassment devices (AHD) or ‘seal scarers’ are used extensively, not only to deter seals from fisheries, but also as mitigation tools to deter marine mammals from potentially harmful sound sources, such as offshore pile driving. To test the effectiveness of AHDs, we conducted two studies with similar experimental set-ups on two key species: harbour porpoises and harbour seals. We exposed animals to 500 ms tone bursts at 12 kHz simulating that of an AHD (Lofitech), but with reduced output levels (source peak-to-peak level of 165 dB re 1 µPa). Animals were localized with a theodolite before, during and after sound exposures. In total, 12 sound exposures were conducted to porpoises and 13 exposures to seals. Porpoises were found to exhibit avoidance reactions out to ranges of 525 m from the sound source. Contrary to this, seal observations increased during sound exposure within 100 m of the loudspeaker. We thereby demonstrate that porpoises and seals respond very differently to AHD sounds. This has important implications for application of AHDs in multi-species habitats, as sound levels required to deter less sensitive species (seals) can lead to excessive and unwanted large deterrence ranges on more sensitive species (porpoises).

scholarly journals Northern bottlenose whales in a pristine environment respond strongly to close and distant navy sonar signals

2019 ◽  
Vol 286 (1899) ◽  
pp. 20182592 ◽  
Author(s):  
Paul J. Wensveen ◽  
Saana Isojunno ◽  
Rune R. Hansen ◽  
Alexander M. von Benda-Beckmann ◽  
Lars Kleivane ◽  
...  
Keyword(s):  
Perceived Risk ◽  
Marine Mammals ◽  
Sound Sources ◽  
Acoustic Environment ◽  
Sound Levels ◽  
Medium Resolution ◽  
Source Distance ◽  
Wide Range ◽  
Beaked Whales ◽  
Northern Bottlenose Whales

Impact assessments for sonar operations typically use received sound levels to predict behavioural disturbance in marine mammals. However, there are indications that cetaceans may learn to associate exposures from distant sound sources with lower perceived risk. To investigate the roles of source distance and received level in an area without frequent sonar activity, we conducted multi-scale controlled exposure experiments ( n = 3) with 12 northern bottlenose whales near Jan Mayen, Norway. Animals were tagged with high-resolution archival tags ( n = 1 per experiment) or medium-resolution satellite tags ( n = 9 in total) and subsequently exposed to sonar. We also deployed bottom-moored recorders to acoustically monitor for whales in the exposed area. Tagged whales initiated avoidance of the sound source over a wide range of distances (0.8–28 km), with responses characteristic of beaked whales. Both onset and intensity of response were better predicted by received sound pressure level (SPL) than by source distance. Avoidance threshold SPLs estimated for each whale ranged from 117–126 dB re 1 µPa, comparable to those of other tagged beaked whales. In this pristine underwater acoustic environment, we found no indication that the source distances tested in our experiments modulated the behavioural effects of sonar, as has been suggested for locations where whales are frequently exposed to sonar.

Anthropogenic sound and marine mammal health: measures of the nervous and immune systems before and after intense sound exposure

2004 ◽  
Vol 61 (7) ◽  
pp. 1124-1134 ◽  
Author(s):  
T A Romano ◽  
M J Keogh ◽  
C Kelly ◽  
P Feng ◽  
L Berk ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Experimental Period ◽  
Delphinapterus Leucas ◽  
White Whale ◽  
Sound Exposure ◽  
Immune Parameters ◽  
Sound Levels ◽  
Before And After ◽  
High Level ◽  
Immune Changes

Anthropogenic sound is a potential stressor for marine mammals that may affect health, as has been demonstrated in other mammals. Therefore, we have initiated investigations on the effects of intense underwater sounds on nervous system activation and immune function in marine mammals. Blood samples were obtained before and after sound exposures (single underwater impulsive sounds (up to 200 kPa) produced from a seismic water gun and (or) single pure tones (up to 201 dB re 1 μPa) resembling sonar “pings” from a white whale, Delphinapterus leucas, and a bottlenose dolphin, Tursiops truncatus, to measure neural-immune parameters. Norepinephrine, epinephrine, and dopamine levels increased with increasing sound levels and were significantly higher after high-level sound exposures (>100 kPa) compared with low-level sound exposures (<100 kPa) or controls (P = 0.003, 0.006, and 0.020) for the white whale. Alkaline phosphatase decreased over the experimental period (P < 0.001), while γ-glutamyltransferase increased over the experimental period (P < 0.001). Significant neural-immune measurements for the dolphin after exposure to impulsive sounds included an increase in aldosterone (P = 0.003) and a decrease in monocytes (P = 0.006). Neural-immune changes to tonal sound exposures were minimal, although changes were observed in multiple neural-immune measures over time.

scholarly journals Effects of exposure to pile-driving sounds on the lake sturgeon, Nile tilapia and hogchoker

2012 ◽  
Vol 279 (1748) ◽  
pp. 4705-4714 ◽  
Author(s):  
Michele B. Halvorsen ◽  
Brandon M. Casper ◽  
Frazer Matthews ◽  
Thomas J. Carlson ◽  
Arthur N. Popper
Keyword(s):  
Nile Tilapia ◽  
Lake Sturgeon ◽  
Pile Driving ◽  
Swim Bladder ◽  
Wave Tube ◽  
Sound Sources ◽  
Severe Injuries ◽  
Sound Exposure ◽  
Sound Levels ◽  
Exposure Levels

Pile-driving and other impulsive sound sources have the potential to injure or kill fishes. One mechanism that produces injuries is the rapid motion of the walls of the swim bladder as it repeatedly contacts nearby tissues. To further understand the involvement of the swim bladder in tissue damage, a specially designed wave tube was used to expose three species to pile-driving sounds. Species included lake sturgeon ( Acipenser fulvescens )—with an open (physostomous) swim bladder, Nile tilapia ( Oreochromis niloticus )—with a closed (physoclistous) swim bladder and the hogchoker ( Trinectes maculatus )—a flatfish without a swim bladder. There were no visible injuries in any of the exposed hogchokers, whereas a variety of injuries were observed in the lake sturgeon and Nile tilapia. At the loudest cumulative and single-strike sound exposure levels (SEL cum and SEL ss respectively), the Nile tilapia had the highest total injuries and the most severe injuries per fish. As exposure levels decreased, the number and severity of injuries were more similar between the two species. These results suggest that the presence and type of swim bladder correlated with injury at higher sound levels, while the extent of injury at lower sound levels was similar for both kinds of swim bladders.

Ground Attenuation Factor Based on Measurements

2021 ◽  
Vol 263 (3) ◽  
pp. 3436-3447
Author(s):  
Dan Lin ◽  
Andrew Eng
Keyword(s):  
Near Field ◽  
Attenuation Factor ◽  
Measurement Data ◽  
Low Frequency ◽  
Sound Sources ◽  
Frequency Sound ◽  
Sound Levels ◽  
Different Types ◽  
Noise Measurements ◽  
Field Sound

Assumptions made on the ground types between sound sources and receivers can significantly impact the accuracy of environmental outdoor noise prediction. A guideline is provided in ISO 9613-2 and the value of ground factor ranges from 0 to 1, depending on the coverage of porous ground. For example, a ground absorption factor of 1 is suggested for grass ground covers. However, it is unclear if the suggested values are validated. The purpose of this study is to determine the sound absorption of different types of ground by measurements. Field noise measurements were made using an omnidirectional loudspeaker and two microphones on three different types of ground in a quiet neighborhood. One microphone was located 3ft from the loudspeaker to record near field sound levels in 1/3 and 1 octave bands every second. The other microphone was located a few hundred feet away to record far field sound in the same fashion as the near field microphone. The types of ground tested were concrete, grass, and grass with trees. Based on the measurement data, it was found that grass and trees absorb high frequency sound well and a ground factor of 1 may be used for 500Hz and up when using ISO 9613-2 methodology. However, at lower frequencies (125 Hz octave band and below), grassy ground reflects sound the same as concrete surfaces. Trees absorb more low frequency sound than grass, but less than ISO 9613-2 suggested.

scholarly journals Does predation by grey seals (Halichoerus grypus) affect Bothnian Sea herring stock estimates?

2012 ◽  
Vol 69 (8) ◽  
pp. 1448-1456 ◽  
Author(s):  
Anna Gårdmark ◽  
Örjan Östman ◽  
Anders Nielsen ◽  
Karl Lundström ◽  
Olle Karlsson ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Halichoerus Grypus ◽  
Grey Seal ◽  
Older Individuals ◽  
Standard Assessment ◽  
Abundance Estimates ◽  
Stock Biomass ◽  
Key Species ◽  
Spawning Stock ◽  
Bothnian Sea

Abstract Gårdmark, A., Östman, Ö., Nielsen, A., Lundström K., Karlsson O., Pönni, J., and Aho, T. 2012. Does predation by grey seals (Halichoerus grypus) affect Bothnian Sea herring stock estimates? – ICES Journal of Marine Science, 69: . Mortality of small pelagic fish due to marine mammals is generally considered to be low compared with other sources of mortality. With recent recoveries of marine mammal predators worldwide, this may no longer hold. The grey seal (Halichoerus grypus) population in the Bothnian Sea has increased fivefold since 1985. Its main prey, herring (Clupea harrengus), is a key species for fisheries in the region. Yet, current stock assessments assume constant natural mortality, leading to a risk of biased stock estimates with increasing predation and misleading analyses of herring population dynamics. We estimated grey seal predation from diet data and reanalysed herring spawning stock biomass (SSB) during 1973–2009. Accounting for predation increased the herring SSB 16% (maximum 19%), but this was within the confidence intervals when ignoring predation. Although mortality in older individuals was inflated when accounting for seal predation, this did not change the conclusions about drivers of herring dynamics. Accounting for grey seal predation is important for abundance estimates of old herring, but currently not for SSB estimates, given the great uncertainties in the standard assessment. The grey seal impact on Bothnian Sea herring will need to be reassessed if stock age composition, grey seal feeding preferences, or total stock development change.

Noise Control Decision Process for Marine Vessels

2014 ◽  
Author(s):  
Raymond W. Fischer ◽  
Louis M. Pettit
Keyword(s):  
Marine Mammals ◽  
Noise Control ◽  
Regulatory Body ◽  
Noise Levels ◽  
Radiated Noise ◽  
Underwater Radiated Noise ◽  
Sound Levels ◽  
Airborne Noise ◽  
Control Decision ◽  
Marine Vessels

There is a price to be paid to achieve compliance with the acoustic requirements imposed by regulatory agencies. Acoustic requirements typically appear in ship specifications as airborne and/or underwater radiated noise limits as the need to preclude hearing loss for crew members and the need to control sound levels experienced by marine mammals receive more recognition. Recent changes and additions to regulatory body requirements addressing compartment airborne noise and underwater radiated noise can be found in IMO Resolution MSC.337(91) Annex 1 and Annex 2 which state that IMO Resolution A.468(XII) “Code on Noise Levels Onboard Ships” shall take effect on 1 July 2014 for all SOLAS compliant vessels. Thus the airborne noise levels in compartments and at on-deck work stations onboard as-built ships seeking a SOLAS certificate will need to be measured, and must demonstrate compliance with noise limits stated in paragraph 4.2 of IMO Resolution A.468(XII). IMO “Guidelines for the Reduction of Underwater Noise from Commercial Shipping to Address Adverse Impacts on Marine Life” dated 7 April 2014 and agencies such as ICES and DNV have established guidance and/or criteria for control of underwater radiated noise from vessels, and these too are now commonly appearing in ship specifications. Specifications referencing such criteria typically require that compliance be demonstrated by at-sea testing of underwater radiated noise. Making the correct decisions during the ship design process will minimize costs for noise control and will provide a positive return on investment. The process of how best to comply with noise limits while minimizing costs through optimization of noise control treatments and design approaches is discussed.

Measurement and Prediction of Sound Exposure Levels by University Wind Bands

2010 ◽  
Vol 25 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Kris Chesky
Keyword(s):  
Linear Regression Analysis ◽  
Critical Role ◽  
Significant Proportion ◽  
Sound Exposure ◽  
Sound Levels ◽  
Wind Bands ◽  
Exposure Levels ◽  
The Mean ◽  
Over Time

The purpose of this study was to determine sound exposure levels generated in two college wind bands. Dosimeter data from a large sample of ensemble-based instructional activities (n = 43) was collected over time and processed to assess associations with predictor variables that may be relevant to this context, including indicators of time spend at various intensity levels, maximum and peak sound levels, degree of variability of sound levels over time, and the percentage of time playing music. The mean dose per event for the entire sample was 109.5% and ranged from 53.8% to 166.9%. Results of linear regression analysis revealed that regressors accounted for a significant proportion of the variance in dose (F = 128.42, p < 0.000) and a statistically significant and very large (96% variance accounted for) contribution to the prediction of dose. Findings implicate the critical role of the instructor and teaching pedagogy.

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