Hearing threshold shifts and recovery in harbor seals (<i>Phoca vitulina</i>) after octave-band noise exposure at 4 kHz

Kastelein, Ronald A.; Gransier, Robin; Hoek, Lean; MacLeod, A.; Terhune, John M.

doi:10.1121/1.4747013

Cited by 33 publications

(31 citation statements)

References 27 publications

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“…2). On day four, her hearing had returned to normal (<2.5 dB TTS; see Kastelein et al, 2012b). The hearing threshold of the seal for the 4 kHz test signal was established daily for months after this, and showed stable baseline hearing threshold levels and initial TTSs.…”

Section: B Severe Tts In a Harbor Sealmentioning

confidence: 96%

“…Due to a manufacturing problem, the transducer (Lubell 1424HP) used during the seal TTS study (Kastelein et al, 2012b) produced an SPL/voltage output that seemed stable, but was 15 dB lower than specified. Unexpectedly, during one session, the transducer produced the SPL/voltage specified by the manufacturer: the source level was 169 dB re 1 lPa at 1 m, the mean received SPL was 163 dB re 1 lPa.…”

Section: B Severe Tts In a Harbor Sealmentioning

confidence: 97%

“…1. The TTS (dB) in the first 4 min after sound exposure as a function of the sound exposure level (SEL), for a harbor porpoise (Kastelein et al, 2012a), for fatiguing sounds at 124 dB re 1 lPa (᭺, 7.5, 15, 30, 60, 120, and 240 min), 136 dB re 1 lPa (ٗ, 7.5, 15, 30, 60, 120, and 240 min), and 148 dB re 1 lPa (᭝, 7.5, 15, 30, 60, 120, and 240 min), and for a harbor seal (Kastelein et al, 2012b), for fatiguing sounds at 124 dB re 1 lPa ( • , 60, 120, and 240 min), 136 dB re 1 lPa (, 7.5, 15, 30, 60, 120, and 240 min), and 148 dB re 1 lPa (᭡, 7.5, 15, 30, 60, 120, and 240 min). Results are shown, from left to right, in order of increasing duration of fatiguing noise.…”

Section: A Comparison Of Tts In a Harbor Porpoise And A Harbor Sealmentioning

confidence: 99%

“…One of the seals avoided exposure to this sound by hauling out; the other stayed in the water during the entire 60-min period. The severe TTS caused by this exposure (SEL: 199 dB re 1 lPa 2 s) was quantified with the methods of Kastelein et al (2012b), except that, as well as 1-4, 4-8, 8-12, 48, and 96 min after the noise exposure stopped, TTS was measured 3, 4, 5, and 10 days after sound exposure.…”

Section: B Severe Tts In a Harbor Sealmentioning

confidence: 99%

“…Kastelein et al (2012a) exposed a harbor porpoise to an OBN centered at 4 kHz at various durations and levels. The same exposure levels and durations were used by Kastelein et al (2012b) in a similar TTS study on two harbor seals (one seal's hearing was tested at the same moments postexposure as that of the harbor porpoise). At 4 kHz, the unmasked hearing thresholds of the specific harbor seals and harbor porpoise were similar (Kastelein et al, 2010a,b).…”

Section: Introduction and Approachmentioning

confidence: 99%

See 4 more Smart Citations

Comparative temporary threshold shifts in a harbor porpoise and harbor seal, and severe shift in a seal

Kastelein¹,

Gransier²,

Hoek³

2013

The Journal of the Acoustical Society of America

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Anthropogenic noise may cause temporary hearing threshold shifts (TTSs) in marine mammals. Tests with identical methods show that harbor porpoises are more susceptible to TTS induced by octave-band white noise (OBN) centered around 4 kHz than harbor seals, although their unmasked (basic) hearing thresholds for that frequency are similar. A harbor seal was exposed for 1 h to an OBN with a very high sound pressure level (SPL), 22-30 dB above levels causing TTS onset. This elicited 44 dB TTS; hearing recovered within 4 days. Thus, for this signal and this single exposure, permanent threshold shift requires levels at least 22 dB above TTS onset levels. The severe TTS in the seal suggests that the critical level (above which TTS increases rapidly with increasing SPL) is between 150 and 160 dB re 1 μPa for a 60 min exposure to OBN centered at 4 kHz. In guidelines on TTS in marine mammals produced by policy makers in many countries, TTS is assumed to follow the equal energy hypothesis, so that when the sound exposure levels of fatiguing sounds are equal, the same TTS is predicted to be induced. However, like previous studies, the present study calls this model into question.

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Section: B Severe Tts In a Harbor Sealmentioning

confidence: 96%

Section: B Severe Tts In a Harbor Sealmentioning

confidence: 97%

Section: A Comparison Of Tts In a Harbor Porpoise And A Harbor Sealmentioning

confidence: 99%

Section: B Severe Tts In a Harbor Sealmentioning

confidence: 99%

Section: Introduction and Approachmentioning

confidence: 99%

See 3 more Smart Citations

Comparative temporary threshold shifts in a harbor porpoise and harbor seal, and severe shift in a seal

Kastelein¹,

Gransier²,

Hoek³

2013

The Journal of the Acoustical Society of America

Self Cite

View full text Add to dashboard Cite

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Measuring responses of harbour seals to potential aversive acoustic mitigation signals using controlled exposure behavioural response studies

Gordon

Blight

Bryant³

et al. 2019

Aquatic Conservation

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1. Some anthropogenic activities pose acute risks for marine species. For example, pile driving could damage the hearing of marine mammals while underwater explosions can also result in physical damage or death. Effective mitigation is required to reduce these risks, but the exclusion zones specified in regulations can extend over hundreds or thousands of metres and seals pose particular problems because they are difficult to detect at sea.2. Aversive sound mitigation aims to exclude animals from high-risk areas before dangerous activities take place by broadcasting specific acoustic signals. Field research is needed to identify signals that might be effective in eliciting short-term avoidance by marine species such as harbour seals (Phoca vitulina). A series of controlled-exposure experiments (CEEs) were undertaken to measure seal movements in response to acoustic deterrent devices (ADD) and predator calls, and to assess the effectiveness of candidate signals for aversive sound mitigation.3. Seals were fitted with UHF/GPS transmitters providing continuous high-resolution tracks and real-time transmissions of their locations. A tracking/playback vessel located seals at sea and transmitted either ADD signals or orca (Orcinus orca) calls over a range of distances while seals were foraging or moving between sites.Behaviour before, during and after exposure was analysed to assess responses. 4. One-hundred and ten CEEs were assessed as being of at least 'adequate' quality.Of the 71 adequate trials with the Lofitech ADD, all 38 at ranges of <1 km (predicted received level 134.6 dB RMS re 1 μPa) elicited a response. The maximum response range was 3123 m (predicted RL: 111 dB RMS re 1 μPa). However, the responses observed did not always result in substantial movements away from the source, especially for seals that were travelling at the time of the exposures.More work is needed to better understand how exposure risks would be reduced in different scenarios.5. The mean net speed of horizontal movements for seals responding to aversive sounds (1.15 m s −1 ) was only 7% higher than their mean travel speed.6. Responses to broadcasts of orca calls were highly variable.

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Exposure of individual harbour seals (Phoca vitulina) and waters surrounding protected habitats to acoustic deterrent noise from aquaculture

Findlay

Hastie

Farcas

et al. 2022

Aquatic Conservation

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1. Pinniped depredation at aquaculture sites is a globally recognized problem. To mitigate depredation, the aquaculture sector uses acoustic deterrent devices (ADDs) as a non-lethal alternative to shooting pinnipeds interacting with caged finfish. However, it is unclear whether sound emissions from ADDs have the potential to also impact non-target pinnipeds at spatial scales relevant to populations.2. Global Positioning System (GPS) tracking data from seven harbour seals tagged in a non-aquaculture context, on the west coast of Scotland, in 2017 were combined with modelled maps of ADD noise to quantify sound exposure and estimate the potential for auditory impairment. The acoustic model applied an energy flux approach across the main frequency range of ADDs (2-40 kHz).Predictions of temporary and permanent auditory threshold shifts were made using seal location data and published noise exposure criteria. The acoustic exposure of waters (10-km buffers) surrounding protected habitats (i.e. designated haul outs and Special Areas of Conservation (SACs)) on the west coast of Scotland was also assessed.3. All tagged seals and waters surrounding 51 of 56 protected sites were predicted to be exposed to ADD noise exceeding median ambient sound levels. Temporary auditory impairment was predicted to occur in one of the seven tagged harbour seals and across 1.7% of waters surrounding protected habitats over a 24-hour period, when assuming a 100% ADD duty cycle.4. Although the predicted risk of auditory impairment appears to be relatively low, these findings suggest that harbour seals inhabiting inshore waters off western Scotland are routinely exposed to ADD noise that exceeds median ambient sound levels. This chronic exposure risks negative consequences for individual harbour seals among the wider population in this region. The use of ADDs to mitigate pinniped depredation should be carefully considered to reduce unintended habitat-wide impacts on non-target species, including pinnipeds that are not specifically interacting with aquaculture.

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Hearing threshold shifts and recovery in harbor seals (Phoca vitulina) after octave-band noise exposure at 4 kHz

Cited by 33 publications

References 27 publications

Comparative temporary threshold shifts in a harbor porpoise and harbor seal, and severe shift in a seal

Comparative temporary threshold shifts in a harbor porpoise and harbor seal, and severe shift in a seal

Measuring responses of harbour seals to potential aversive acoustic mitigation signals using controlled exposure behavioural response studies

Exposure of individual harbour seals (Phoca vitulina) and waters surrounding protected habitats to acoustic deterrent noise from aquaculture

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