Marine Mammal Noise Exposure Criteria: Initial Scientific Recommendations

Journal Article

Title: Marine Mammal Noise Exposure Criteria: Initial Scientific Recommendations
Publication Date:
December 01, 2007
Journal: Aquatic Mammals
Volume: 33
Issue: 4
Pages: 1-121
Stressor:

Document Access

Website: External Link

Citation

Southall, B.; Bowles, A.; Ellison, W.; Finneran, J.; Gentry, R.; Greene, C. Jr.; Kastak, D.; Ketten, D.; Miller, J.; Nachtigall, P.; Richardson, W.; Thomas, J.; Tyack, P. (2007). Marine Mammal Noise Exposure Criteria: Initial Scientific Recommendations. Aquatic Mammals, 33(4), 1-121.
Abstract: 

A group of experts in acoustic research from behavioral, physiological, and physical disciplines was convened over a several year period. The purpose of this panel was to review the expanding literature on marine mammal hearing and on physiological and behavioral responses to anthropogenic sound, and to propose exposure criteria for certain effects. The group employed all available relevant data to predict noise exposure levels above which adverse effects on various groups of marine mammals are expected. Recent advances in these fields and the pressing need for a science-based paradigm to assess the effects of sound exposure were the primary motivations for this effort. Two categories of effects were considered: (1) injury and (2) behavioral disturbance. The proposed criteria for the onset of these effects were further segregated according to the functional hearing capabilities of different marine mammal groups, and according to the different categories and metrics of typical anthropogenic sounds in the ocean. The group achieved many of its objectives but acknowledges certain limitations in the proposed criteria because of scarcity or complete absence of information about some key topics. A major component of these recommendations is a call for specific research on critical topics to reduce uncertainty and improve future exposure criteria for marine mammals. This publication marks the culmination of a long and challenging initial effort, but it also initiates a necessary, iterative process to apply and refine noise exposure criteria for different species of marine mammals.

 

 

 

Table 1

Sound types, acoustic characteristics, and selected examples of anthropogenic sound sources; note sound types are based on characteristics measured at the source. In certain conditions, sounds classified as pulses at the source may lack these characteristics for distant receivers.

Sound Type Acoustic Characteristics (at source) Examples
Single pulse Single acoustic event; > 3-dB difference between received level using impulse vs equivalent continuous time constant Single explosion; sonic boom; single airgun, watergun, pile strike, or sparker pulse; single ping of certain sonars, depth sounders, and pingers
Multiple pulses Multiple discrete acoustic events within 24 h; > 3-dB difference between received level using impulse vs equivalent continuous time constant Serial explosions; sequential airgun, watergun, pile strikes, or sparker pulses; certain active sonar (IMAPS); some depth sounder signals
Nonpulses Single or multiple discrete acoustic events within 24 h; < 3-dB difference between received level using impulse vs equivalent continuous time constant Vessel/aircraft passes; drilling; many construction or other industrial operations; certain sonar systems (LFA, tactical mid-frequency); acoustic harassment/deterrent devices; acoustic tomography sources (ATOC); some depth sounder signals

 

Table 2

Functional marine mammal hearing groups, auditory bandwidth (estimated lower to upper frequency hearing cut-off), genera represented in each group, and group-specific (M) frequency-weightings.

Functional Hearing Group Estimated Auditory Bandwidth Genera Represented (Number species/subspecies) Frequency-Weighting Network
Low-frequency cetaceans 7 Hz to 22 kHz Balaena, Caperea, Eschrichtius, Megaptera, Balaenoptera (13 species/subspecies) Mlf (lf: low-frequency cetacean)
Mid-frequency cetaceans 150 Hz to 160 kHz Steno, Sousa, Sotalia, Tursiops, Stenella, Delphinus, Lagenodelphis, Lagenorhynchus, Lissodelphis, Grampus, Peponocephala, Feresa, Pseudorca, Orcinus, Globicephala, Orcaella, Physeter, Delphinapterus, Monodon, Ziphius, Berardius, Tasmacetus, Hyperoodon, Mesoplodon (57 species/subspecies) Mmf (mf: mid-frequency cetaceans)
High-frequency cetaceans 200 Hz to 180 kHz Phocoena, Neophocaena, Phocoenoides, Platanista, Inia, Kogia, Lipotes, Pontoporia, Cephalorhynchus (20 species/subspecies) Mhf (hf: high-frequency cetaceans)
Pinnipeds in water 75 Hz to 75 kHz Arctocephalus, Callorhinus, Zalophus, Eumetopias, Neophoca, Phocarctos, Otaria, Erignathus, Phoca, Pusa, Halichoerus, Histriophoca, Pagophilus, Cystophora, Monachus, Mirounga, Leptonychotes, Ommatophoca, Lobodon, Hydrurga, and Odobenus (41 species/subspecies) Mpw (pw: pinnipeds in water)
Pinnipeds in air 75 Hz to 30 kHz Same species as pinnipeds in water (41 species/subspecies) Mpa (pa: pinnipeds in air)

 

Table 3

Proposed injury criteria for individual marine mammals exposed to “discrete” noise events (either single or multiple exposures within a 24-h period; see Chapter 2).

  Sound Type
Marine Mammal Group Single Pulses Multiple Pulses Nonpulses
Low-frequency cetaceans Cell 1 Cell 2 Cell 3
Sound pressure level 230 dB re: 1 μPa (peak) (flat) 230 dB re: 1 μPa (peak) (flat) 230 dB re: 1 μPa (peak) (flat)
Sound exposure level 198 dB re: 1 μPa2s (Mlf) 198 dB re: 1 μPa2s (Mlf) 215 dB re: 1 μPa2s (Mlf)
Mid-frequency cetaceans Cell 4 Cell 5 Cell 6
Sound pressure level 230 dB re: 1 μPa (peak) (flat) 230 dB re: 1 μPa (peak) (flat) 230 dB re: 1 μPa (peak) (flat)
Sound exposure level 198 dB re: 1 μPa2s (Mmf) 198 dB re: 1 μPa2s (Mmf) 215 dB re: 1 μPa2s (Mmf)
High-frequency cetaceans Cell 7 Cell 8 Cell 9
Sound pressure level 230 dB re: 1 μPa (peak) (flat) 230 dB re: 1 μPa (peak) (flat) 230 dB re: 1 μPa (peak) (flat)
Sound exposure level 198 dB re: 1 μPa2s (Mhf) 198 dB re: 1 μPa2s (Mhf) 215 dB re: 1 μPa2s (Mhf)
Pinnipeds (in water) Cell 10 Cell 11 Cell 12
Sound pressure level 218 dB re: 1 μPa (peak) (flat) 218 dB re: 1 μPa (peak) (flat) 218 dB re: 1 μPa (peak) (flat)
Sound exposure level 186 dB re: 1 μPa2s (Mpw) 186 dB re: 1 μPa2s (Mpw) 203 dB re: 1 μPa2s (Mpw)
Pinnipeds (in air) Cell 13 Cell 14 Cell 15
Sound pressure level 149 dB re: 20 μPa (peak) (flat) 149 dB re: 20 μPa (peak) (flat) 149 dB re: 20 μPa (peak) (flat)
Sound exposure level 144 dB re: 20 μPa2s (Mpa) 144 dB re: 20 μPa2s (Mpa) 144.5 dB re: 20 μPa2s (Mpa)

 

Table 4

Severity scale for ranking observed behavioral responses of free-ranging marine mammals and laboratory subjects to various types of anthropogenic sound.

Response score1 Corresponding behaviors (Free-ranging subjects)2 Corresponding behaviors (Laboratory subjects)2
0
  • No observable response
  • No observable response
1
  • Brief orientation response (investigation/visual orientation)
  • No observable response
2
  • Moderate or multiple orientation behaviors
  • Brief or minor cessation/modification of vocal behavior
  • Brief or minor change in respiration rates
  • No observable negative response; may approach sounds as a novel object
3
  • Prolonged orientation behavior
  • Individual alert behavior
  • Minor changes in locomotion speed, direction, and/or dive profile but no avoidance of sound source
  • Moderate change in respiration rate
  • Minor cessation or modification of vocal behavior (duration < duration of source operation), including the Lombard Effect
  • Minor changes in response to trained behaviors (e.g., delay in stationing, extended inter-trial intervals)
4
  • Moderate changes in locomotion speed, direction, and/or dive profile but no avoidance of sound source
  • Brief, minor shift in group distribution
  • Moderate cessation or modification of vocal behavior (duration ~duration of source operation)
  • Moderate changes in response to trained behaviors (e.g., reluctance to return to station, long inter-trial intervals)
5
  • Extensive or prolonged changes in locomotion speed, direction, and/or dive profile but no avoidance of sound source
  • Moderate shift in group distribution
  • Change in inter-animal distance and/or group size (aggregation or separation)
  • Prolonged cessation or modification of vocal behavior (duration > duration of source operation)
  • Severe and sustained changes in trained behaviors (e.g., breaking away from station during experimental sessions)
6
  • Minor or moderate individual and/or group avoidance of sound source
  • Brief or minor separation of females and dependent offspring
  • Aggressive behavior related to noise exposure (e.g., tail/flipper slapping, fluke display, jaw clapping/gnashing teeth, abrupt directed movement, bubble clouds)
  • Extended cessation or modification of vocal behavior
  • Visible startle response
  • Brief cessation of reproductive behavior
  • Refusal to initiate trained tasks
7
  • Extensive or prolonged aggressive behavior
  • Moderate separation of females and dependent offspring
  • Clear anti-predator response
  • Severe and/or sustained avoidance of sound source
  • Moderate cessation of reproductive behavior
  • Avoidance of experimental situation or retreat to refuge area (£ duration of experiment)
  • Threatening or attacking the sound source
8
  • Obvious aversion and/or progressive sensitization
  • Prolonged or significant separation of females and dependent offspring with disruption of acoustic reunion mechanisms
  • Long-term avoidance of area (> source operation)
  • Prolonged cessation of reproductive behavior
  • Avoidance of or sensitization to experimental situation or retreat to refuge area (> duration of experiment)
9
  • Outright panic, flight, stampede, attack of conspecifics, or stranding events
  • Avoidance behavior related to predator detection
  • Total avoidance of sound exposure area and refusal to perform trained behaviors for greater than a day
1Ordinal scores of behavioral response severity are not necessarily equivalent for free-ranging vs laboratory conditions.
2Any single response results in the corresponding score (i.e., all group members and behavioral responses need not be observed). If multiple responses are observed, the one with the highest score is used for analysis.

 

Table 5

Proposed behavioral response criteria for individual marine mammals exposed to various sound types; specific threshold levels are proposed for single pulses. See the referenced text sections and tables for severity scale analyses of behavioral responses to multiple pulses and nonpulses.

  Sound Type
Marine Mammal Group Single Pulses Multiple Pulses Nonpulses
Low-frequency cetaceans Cell 1 Cell 2 Cell 3
Sound pressure level 224 dB re: 1 μPa (peak) (flat) Table 6 & 7 Table 14 & 15
Sound exposure level 183 dB re: 1 μPa2s (Mlf) Not applicable Not applicable
Mid-frequency cetaceans Cell 4 Cell 5 Cell 6
Sound pressure level 224 dB re: 1 μPa (peak) (flat) Table 8 & 9 Table 16 & 17
Sound exposure level 183 dB re: 1 μPa2s (Mmf) Not applicable Not applicable
High-frequency cetaceans Cell 7 Cell 8 Cell 9
Sound pressure level 224 dB re: 1 μPa (peak) (flat) Table 18 & 19 Table 18 & 19
Sound exposure level 183 dB re: 1 μPa2s (Mhf) Not applicable Not applicable
Pinnipeds (in water) Cell 10 Cell 11 Cell 12
Sound pressure level 212 dB re: 1 μPa (peak) (flat) Table 10 & 11 Table 20 & 21
Sound exposure level 171 dB re: 1 μPa2s (Mpw) Not applicable Not applicable
Pinnipeds (in air) Cell 13 Cell 14 Cell 15
Sound pressure level 109 dB re: 20 μPa (peak) (flat) Table 12 & 13 Table 22 & 23
Sound exposure level 100 dB re: 20 μPa2s (Mpa) Not applicable Not applicable

 

Table 6

Summary of behavioral responses by different species of low-frequency cetaceans exposed to multiple pulses (Cell 2) by type of sound source, available acoustic metrics, description of behavioral response (by individual and/or group), and a summary of corresponding severity score(s); where airgun array volume is stated, this is the total volume for all operating airguns in the array; 1 L = 61 in3. Specific severity scores for each study are given in Table 7, and more details are given in Appendix B. Exposure RLs are given in dB SPL, which are RMS sound pressure levels (dB re: 1 μPa) over the duration of a pulse.

Study Reference
number
(for Table 7)
Subject Species Sound source Type of acoustic
measurements
Type of individual and/or group behavioral responses Study included
in severity
scale
Summary of severity
scale analysis
(see Table 7)
Malme et al. (1983) 1 Gray whales Single airgun (1.64 L) & 20-gun 65.5-L airgun array Calibrated RL measurements made in situ near areas of exposure Land-based observations of individuals/groups; movement and respiration patterns during and without airguns Yes Exposure RLs 140-180 dB SPL; response severity scores: 0, 1, 3, 5 & 6
Malme et al. (1984) 2 Gray whales Single airgun and airgun array Calibrated RL measurements made in situ near areas of exposure Land-based observations of individuals/ groups; movement and respiration patterns during and without airguns Yes Exposure RLs 140-180 dB SPL; response severity scores: 0, 1, 3, 5 & 6
Richardson et al. (1986) 3 Bowhead whales (feeding) Single airgun (0.66 L) and 30-gun 47-L array Calibrated RL measurements made in situ near areas of exposure Aerial observations of individuals/groups; movement and respiration patterns during and without airguns Yes Exposure RLs 140-180 dB SPL; response severity scores: 0, 1 & 6
Ljungblad et al. (1988) 4 Bowhead whales (feeding) Single airgun (1.3 L) or 18- to 20-gun array Calibrated RL measurements made in situ near areas of exposure Aerial observations of individuals/groups; movement patterns and behavioral responses during and without airguns Yes Exposure RLs 140-180 dB SPL; response severity score: 6
Todd et al. (1996) 5 Humpback whales Explosions Limited to nominal measurements of explosives used (not measured on or near subjects) Visual observations of whale behavior before and during use of explosives No Exposure RLs 150-160 dB SPL; response severity score: 3
McCauley et al. (1998) 6 Humpback whales (migrating) Single airgun (0.33 L) and several arrays Calibrated RL measurements made in situ near areas of exposure Aerial and boat-based observations of individuals/ groups; movement and behavioral patterns during and without airguns No Exposure RLs 150-170 dB SPL; response severity scores: 6 & 7
Richardson et al. (1999) 7 Bowhead whales (migrating) Airgun array (6 to 16 guns; 9 to 25 L) Calibrated RL measurements made in situ near areas of exposure Aerial surveys of distribution of individuals/ groups Yes Exposure RLs 110-140 dB SPL; response severity scores: 0, 1, 5 & 6
McCauley et al. (2000) 8 Humpback whales (socializing) Single airgun (0.33 L) Calibrated RL measurements made in situ near areas of exposure Boat-based observations of individuals/ groups; movement and behavioral patterns during and without airguns Yes Exposure RLs 140-180 dB SPL; response severity score: 6
Miller et al. (2005) 9 Bowhead whales (feeding) Airgun array (24 guns; 36.9 L) Calibrated RL measurements made in situ near areas of exposure Vessel-based observations of individuals; aerial surveys of distribution; movement/ diving patterns and behavioral responses during and without airguns Yes Exposure RLs 140-180 dB SPL; response severity scores: 0 & 6
Reeves et al. (1984) Not Included Bowhead whales (migrating) Seismic airgun array Insufficient data for this analysis Insufficient data for this analysis Yes N/A
Malme et al. (1985) Not Included Humpback whales Seismic airgun array Insufficient data for this analysis Insufficient data for this analysis No N/A
Malme et al. (1986, 1988) Not Included Gray whales Single airgun and airgun array Insufficient data for this analysis Insufficient data for this analysis No N/A
Koski & Johnson (1987) Not Included Bowhead whales (migrating) Seismic airgun Insufficient data for this analysis Insufficient data for this analysis No N/A

 

Table 7

Number (in bold) of low-frequency cetaceans (individuals and/or groups) reported as having behavioral responses to multiple pulse noise; responses were categorized into 10-dB RL bins, ranked by severity of the behavioral response (see Table 4 for severity scaling), and combined with other observations having the same RL/severity score. A summary of the individual studies included in this table is given in the “Low-Frequency Cetaceans/Multiple Pulses (Cell 2)” section of this chapter. Parenthetical subscripts indicate the reference reporting the observations as listed in Table 6.

Received RMS sound pressure level (dB re: 1 μPa)
Response score 80 to <90 90 to <100 100 to <110 110 to <120 120 to <130 130 to <140 140 to <150 150 to <160 160 to <170 170 to <180 180 to <190 190 to <200
9                        
8                        
7               1.0(6)        
6       9.5(7) 47.4(7) 2.2(7) 3.4(4,6,8) 5.8(1,2,3,6) 4.5(1,2,3,4,6) 8.3(1,2,4,8,9)    
5         1.0(7)   1.0(4) 1.0(1,2)        
4                        
3                 1.0(1,2) 1.0(1,2)    
2                        
1       5.0(7) 6.0(7) 1.0(7) 2.5(1,2,3) 3.0(5)        
0       59.8(7) 17.7(7) 1.1(7,9) 0.1(9) 0.6(3,9) 6.8(1,2,3,9) 6.3(1,2,9)    

 

Table 8

Summary of behavioral responses by different species of mid-frequency cetaceans exposed to multiple pulses (Cell 5) by type of sound source, available acoustic metrics, description of behavioral response (by individual and/or group), and a summary of corresponding severity score(s); specific severity scores for each study are given in Table 9 and more details are given in Appendix B. Exposure RLs are given in dB SPL, which are RMS sound pressure levels (dB re: 1 μPa) over the duration of a pulse.

Study Reference
number
(for Table 9)
Subject Species Sound source Type of acoustic
measurements
Type of individual and/or group behavioral responses Study included
in severity
scale
Summary of severity
scale analysis
(see Table 9)
Madsen & Møhl (2000) 1 Sperm whales Small explosives (several per day) Calibrated RL measurements made in situ near areas of exposure Vessel-based observations of individuals, including visual detection and passive acoustic monitoring of vocalizations Yes Exposure RLs 170- 180 dB SPL; response severity score: 0
Madsen et al. (2002) 2 Sperm whales Airgun array (distant) Calibrated RL measurements made in situ near areas of exposure Vessel-based observations of individuals, including visual detection and passive acoustic monitoring of vocalizations Yes Exposure RLs 120- 140 dB SPL; response severity score: 0
Miller et al. (2005) 3 Beluga Airgun array (24 guns; 36.9 L) Calibrated RL measurements made in situ near areas of exposure Vessel-based observations of individuals; aerial surveys of distribution; movement/diving patterns and behavioral responses during and without airguns Yes Exposure RLs 100- 150 dB SPL; response severity scores: 0 & 6
Akamatsu et al. (1993) 4 False killer whales (captive) Numerous sounds, including pulse sequences Calibrated RL measurements made in situ within experimental enclosure Visual observations of behavioral responses within experimental context in laboratory conditions Yes Exposure RLs 170- 180 dB SPL; response severity scores: 0 & 6
André et al. (1997) Not Included Sperm whales Natural and artificial pulses (repeated) Insufficient data for this analysis Vessel-based observations of individuals; diving patterns and vocal behavior No N/A
Stone (2003) Not Included Several mid-frequency cetacean species Seismic airgun arrays (various) Insufficient data for this analysis Vessel-based observations of individuals; sightings data and avoidance behavior No N/A

 

Table 9

Number (in bold) of mid-frequency cetaceans (individuals and/or groups) reported as having behavioral responses to multiple pulse noise; responses were categorized into 10-dB RL bins, ranked by severity of the behavioral response (see Table 4 for severity scaling), and combined with other observations having the same RL/severity score. A summary of the individual studies included in this table is given in the “Mid-Frequency Cetaceans/Multiple Pulses (Cell 5)” section of this chapter. Parenthetical subscripts indicate the reference reporting the observations as listed in Table 8.

Received RMS sound pressure level (dB re: 1 μPa)
Response score 80 to <90 90 to <100 100 to <110 110 to <120 120 to <130 130 to <140 140 to <150 150 to <160 160 to <170 170 to <180 180 to <190 190 to <200+
9                        
8                        
7                        
6         0.17(3) 0.17(3) 0.17(3)     1.3(4)    
5                        
4                        
3                        
2                        
1           0.3(2)            
0     0.25(3) 0.25(3) 3.0(2) 4.0(2)       6.7(1,4)    

 

Table 10

Summary of behavioral responses by different species of pinnipeds in water exposed to multiple pulses (Cell 11) by type of sound source, available acoustic metrics, description of behavioral response (by individual and/or group), and a summary of corresponding severity score(s); specific severity scores for each study are given in Table 11 and more details are given in Appendix B. Exposure RLs are given in dB SPL, which are RMS sound pressure levels (dB re: 1 μPa) over the duration of a pulse.

Study Reference
number
(for Table 11)
Subject Species Sound source Type of acoustic
measurements
Type of individual and/or group behavioral responses Study included
in severity
scale
Summary of severity
scale analysis
(see Table 11)
Harris et al. (2001) 1 Ringed (mainly), bearded, and spotted seals Single airgun and 11-gun, 21.6-L array RLs measured in situ near individuals observed in defined spatial zones Vessel-based observations of individuals within specified zones over a limited range Yes Exposure RLs 160- 200 dB SPL; response severity scores: 0 & 6
Blackwell et al. (2004b) 2 Ringed seals Pipe-driving sounds (construction) RLs measured in situ near individuals observed (detailed measurements, including peak pressure, RMS, SEL, and duration) Land-based observations of individuals; movement and response patterns during pipedriving (note that construction activities had been underway for a considerable period before observations) Yes Exposure RLs 150-160 dB SPL; response severity scores: 0 & 1
Miller et al. (2005) 3 Ringed and bearded seals Airgun array (24 airguns; 36.9 L) Calibrated RL measurements made in situ near areas of exposure Vessel-based observations of individuals; movement patterns and behavioral responses during and without airguns Yes Exposure RLs 170-200 dB SPL; response severity score: 0
Shaughnessy et al. (1981) Not Included California sea lions Seal bombs (small explosives) Insufficient data for this analysis Visual observations of individual responses over multiple exposures No N/A
Mate & Harvey (1987) Not Included California sea lions Seal bombs (small explosives) Insufficient data for this analysis Visual observations of individual responses over multiple exposures No N/A
Moulton et al. (2003, 2005) Not Included Ringed seals   Calibrated measurements made in the area of exposure Complicated by simultaneous exposure to pulse and nonpulse sources No N/A

 

Table 11

Number (in bold) of pinnipeds in water (individuals and/or groups) reported as having behavioral responses to multiple pulse noise. Responses were categorized into 10-dB RL bins, ranked by severity of the behavioral response (see Table 4 for severity scaling), and combined with other observations having the same RL/severity score; a summary of the individual studies included in this table is given in the “Pinnipeds in Water/Multiple Pulses (Cell 11)” section of this chapter. Parenthetical subscripts indicate the reference reporting the observations as listed in Table 10.

Received RMS sound pressure level (dB re: 1 μPa)
Response score 80 to <90 90 to <100 100 to <110 110 to <120 120 to <130 130 to <140 140 to <150 150 to <160 160 to <170 170 to <180 180 to <190 190 to <200
9                        
8                        
7                        
6                 1.7(1) 2.1(1)   45.4(1)
5                        
4                        
3                        
2                        
1           0.3(2)            
0               0.7(2) 5.3(1) 30.3(1,3) 0.3(3) 9.9(1,3)

 

Table 12

Summary of behavioral responses by different species of pinnipeds in air exposed to multiple pulses (Cell 14) by type of sound source, available acoustic metrics, description of behavioral response (by individual and/or group), and a summary of corresponding severity score(s); specific severity scores for each study are given in Table 13 and more details are given in Appendix B. Exposure RLs are given in dB SPL, which are RMS sound pressure levels (dB re: 20 μPa) over the duration of a pulse.

Study Reference
number
(for Table 13)
Subject Species Sound source Type of acoustic
measurements
Type of individual and/or group behavioral responses Study included
in severity
scale
Summary of severity
scale analysis
(see Table 13)
Blackwell et al. (2004b) 1 Ringed seals Pipe-driving sounds (construction) RLs measured in situ near individuals observed (detailed measurements, including peak pressure, RMS, SEL, and duration) Land-based observations of individuals; movement and response patterns during pipe-driving (note that construction activities had been underway for a considerable period before observations) Yes Exposure RLs 60-80 dB SPLre: 20 μPa; response severity scores: 0 & 1
Perry et al. (2002) Not Included Harbor and gray seals Repeated sonic booms Measured sound overpressure levels on breeding beaches, but not RLs at positions of exposed animals Land-based observations of animal presence, behavior, and heart rate (note long history of sonic booms in the area) No N/A

 

Table 13

Number (in bold) of pinnipeds in air (individuals and/or groups) reported as having behavioral responses to multiple pulse noise; responses were categorized into 10-dB RL bins, ranked by severity of the behavioral response (see Table 4 for severity scaling), and combined with other observations having the same RL/severity score. A summary of the individual studies included in this table is given in the “Pinnipeds in Air/Multiple Pulses (Cell 14)” section of this chapter. Parenthetical subscripts indicate the reference reporting the observations as listed in Table 12.

Received RMS sound pressure level (dB re: 20 μPa)
Response score 50 to <60 60 to <70 70 to <80 80 to <90 90 to <100 100 to <110 110 to <120
9                   
8                   
7                   
6                   
5                   
4                   
3                   
2                   
1   0.125(1)               
0   0.625(1) 0.25(1)             

 

Table 14

Summary of behavioral responses by different species of low-frequency cetaceans exposed to nonpulses (Cell 3) by type of sound source, available acoustic metrics, description of behavioral response (by individual and/or group), and a summary of corresponding severity score(s); specific severity scores for each study are given in Table 15 and more details are given in Appendix C. Exposure RLs are given in dB SPL, which are RMS sound pressure levels (dB re: 1 μPa).

Study Reference
number
(for Table 15)
Subject Species Sound source Type of acoustic
measurements
Type of individual and/or group behavioral responses Study included
in severity
scale
Summary of severity
scale analysis
(see Table 15)
Baker et al. (1982) 1 Humpback whales Vessel noise and presence Individual RLs not reported but vessels identical to previous measurements Vessel-based observations of individual movement and behavioral patterns around vessels Yes Exposure RLs 100-140 dB SPL; severity scores: 0 & 6
Malme et al. (1983, 1984) 2 Gray whales (migrating) Playbacks of drilling and machinery noise RLs measured in situ near individuals observed Shore-based observations of individual movement and behavioral patterns around simulated drilling operations/platforms Yes Exposure RLs 90-150 dB SPL; severity scores: 0 & 6
Malme et al. (1986) 3 Gray whales (feeding) Playbacks of drilling noise RLs measured in situ near individuals observed Vessel-based observations of individual movement and behavioral patterns before and during playbacks Yes Exposure RLs 100-120 dB SPL; severity scores: 0 & 6
Richardson et al. (1990b) 4 Bowhead whales (migrating) Drilling noise playbacks Detailed and calibrated source and transmission loss measurements allowed good RL estimates Visual observations of individual movement and behavioral patterns before, during, and after exposure to drilling sounds Yes Exposure RLs 100-140 dB SPL; severity scores: 0 & 6
McCauley et al. (1996) 5 Humpback whales Vessel noise and presence RLs measured in situ near individuals observed Visual observations of individual movement and behavioral patterns during vessel approaches Yes Exposure RLs 110-130 dB SPL; severity score: 6
Frankel & Clark (1998) 6 Humpback whales Low-frequency M-sequence playback Calibrated RL measurements made in situ near areas of exposure Visual observations of individual movement and behavioral patterns before, during, and after playbacks Yes Exposure RLs 120-130 dB SPL; severity score: 6
Biassoni et al. (2000); Miller et al. (2000) 7 Humpback whales Low-frequency sonar playback Calibrated RL measurements made in situ near areas of exposure Visual observations of individual movement and behavioral patterns before, during, and after playbacks Yes Exposure RLs 110-160 dB SPL; severity scores: 2 & 4
Croll et al. (2001) 8 Blue and fin whales (feeding) Low-frequency sonar playback Calibrated RL measurements and modeling for area of exposure Individual responses not reported but a general observation of feeding behavior with/without sonar Yes Exposure RLs 140-150 dB SPL; severity score: 0
Palka & Hammond (2001) 9 Minke whales Vessel noise and presence RL estimates based on source and environmental characteristics Visual observations of individual and group movements and behavioral patterns during vessel approaches Yes Exposure RLs 110-120 dB SPL; severity score: 3
Nowacek et al. (2004) 10 Right whales Playbacks of several nonpulses Subjects wore calibrated tags that measured RL and behavior/movement Detailed measurements of vocal and physical reactions of animals before, during, and after playbacks Yes Exposure RLs 120-150 dB SPL; severity scores: 0 & 7
Dahlheim (1987) Not included Gray whales Playbacks of nonpulses Insufficient data for this analysis Visual and acoustic observations of individuals No N/A
Borggaard et al. (1999) Not included Various cetaceans Industrial noise Some RL measurements and modeling in area Insufficient data on individual responses for this analysis No N/A
Frankel & Clark (2000) Not included Humpback whales ATOC source Some RL measurements and modeling in area Insufficient data on individual responses for this analysis No N/A
Schick & Urban (2000) Not included Bowhead whales Drillships Insufficient data for this analysis Visual observations of individuals around rigs No N/A
Frankel & Clark (2002) Not included Humpback whales ATOC source Some RL measurements and modeling in area Insufficient data on individual responses for this analysis No N/A
Jahoda et al. (2003) Not included Fin whales Vessel noise and presence Insufficient data for this analysis Visual observations of individuals during approaches No N/A
Mobley (2005) Not included Humpback whales ATOC source Some RL measurements and modeling in area Insufficient data on individual responses for this analysis No N/A

 

Table 15

Number (in bold) of low-frequency cetaceans (individuals and/or groups) reported as having behavioral responses to nonpulses; responses were categorized into 10-dB RL bins, ranked by severity of the behavioral response (see Table 4 for severity scaling), and combined with other observations having the same RL/severity score. A summary of the individual studies included in this table is given in the “Low-Frequency Cetaceans/Nonpulses (Cell 3)” section of this chapter. Parenthetical subscripts indicate the reference reporting the observations as listed in Table 14.

Received RMS sound pressure level (dB re: 1 μPa)
Response score 80 to <90 90 to <100 100 to <110 110 to <120 120 to <130 130 to <140 140 to <150 150 to <160 160 to <170 170 to <180 180 to <190 190 to <200
9                        
8                        
7           2.5(10) 1.5(10)          
6   4.9(2) 7.4(1,2,4) 16.2(1,2,3,5) 13.6(2,5) 4.2(1,2) 0.8(2)          
5                        
4       3.0(5,7) 1.0(7)   1.0(7)          
3     1,117(9) 0.27(6)                
2     0.5(7) 4.0(7) 5.0(7) 2.0(7) 1.0(7)          
1                        
0 1.1(2) 82.6(2,3,4) 33.9(1,2,3,4) 7.08(2,4,6,10) 1.45(2,8,10)              

 

Table 16

Summary of behavioral responses by different species of mid-frequency cetaceans exposed to nonpulses (Cell 6) by type of sound source, available acoustic metrics, description of behavioral response (by individual and/or group), and a summary of corresponding severity score(s); specific severity scores for each study are given in Table 17 and more details are given in Appendix C. Exposure RLs are given in dB SPL, which are RMS sound pressure levels (dB re: 1 μPa).

Study Reference
number
(for Table 17)
Subject Species Sound source Type of acoustic
measurements
Type of individual and/or group behavioral responses Study included
in severity
scale
Summary of severity
scale analysis
(see Table 17)
Watkins & Schevill (1975) 1 Sperm whales Pingers RLs measured in situ near individuals observed Passive acoustic monitoring of vocal output of individuals during exposure Yes Exposure RLs 80-90 dB SPL; severity score: 3
Awbrey & Stewart (1983) 2 Belugas Playbacks of drilling sounds RL estimates based on source and environmental characteristics Visual observations of individual and group movements and behavioral patterns during exposure and control trials Yes Exposure RLs 110-150 dB SPL; severity scores: 0, 1, 2 & 6
LGL & Greeneridge (1986) 3 Belugas and narwhals Ship and ice-breaking noise Calibrated RL measurements made in situ near areas of exposure Ice-based and aerial observations of groups of animals; movement and behavioral patterns before, during, and after ice-breaking Yes Exposure RLs 90-120 dB SPL; severity scores: 0, 1, 2, 3 & 8
Richardson et al. (1990b) 4 Belugas Playbacks of drilling sounds RL estimates based on source and environmental characteristics plus sonobuoy data Ice-based and aerial observations of individual and group movements and behavior during exposure and control trials Yes Exposure RLs 100-130 dB SPL; severity scores: 0, 1, 3 & 4
Gordon et al. (1992) 5 Sperm whales Vessel noise and presence Calibrated RL measurements made in situ near areas of exposure Vessel-based observations and passive acoustic monitoring of individuals; movement patterns and behavioral responses Yes Exposure RLs 110-120 dB SPL; severity score: 3
Palka & Hammond (2001) 6 White-sided and white-beaked dolphins Vessel noise and presence RL estimates based on source and environmental characteristics Visual observations of individual and group movements and behavioral patterns during vessel approaches Yes Exposure RLs 110-120 dB SPL; severity score: 3
Morton & Symonds (2002) 7 Killer whales Various AHDs RL estimates based on source and environmental characteristics Census data for individual and group sightings used to estimate “exclusion” zones Yes Exposure RLs 140-150 dB SPL; severity score: 8
Buckstaff (2004) 8 Bottlenose dolphins Vessel noise and presence (approaches) Calibrated RL measurements made in situ near areas of exposure Passive acoustic monitoring of individual vocal output during vessel approaches Yes Exposure RLs 110-120 dB SPL; severity score: 2
NRL (2004a, 2004b); NMFS (2005) 9 Killer whales Mid-frequency active military sonar Some calibrated RL measurements and RL estimates from modeling source and environmental characteristics Visual observations of individual and group movements and behavioral patterns before, during, and after incidental exposure Yes Exposure RLs 160-170 dB SPL; severity score: 6
Monteiro-Neto et al. (2004) 10 Tucuxi (river dolphins) Dukane® Netmark ADDs RL estimates based on source and environmental characteristics Visual observations of individual and group movements and behavioral patterns during exposure and control trials Yes Exposure RLs 110-120 dB SPL; severity score: 6
Morisaka et al. (2005) 11 Indo-Pacific dolphins Vessel noise and presence Calibrated RL measurements made in situ near areas of exposure Passive acoustic monitoring of individual vocal output during vessel approaches Yes Exposure RLs 120-130 dB SPL; severity score: 5
Nachtigall et al. (2003) 12 Bottlenose dolphins (captive) Nonpulse noise (bands) Calibrated RL measurements in situ within test enclosure Visual observations of behavioral responses within experimental lab context Yes Exposure RLs 170-180 dB SPL; severity score: 6
Finneran & Schlundt (2004) 13 Bottlenose dolphins (captive) Nonpulse noise (tones) Calibrated RL measurements made in situ within test enclosure Visual observations of behavioral responses within experimental context in laboratory conditions Yes Exposure RLs 180-200 dB SPL; severity scores: 0 & 8
Rendell & Gordon (1999) Not included Long-finned pilot whales Active military sonar Insufficient data for this analysis Passive acoustic measurements of whistle rates No N/A
Chilvers & Corkeron (2001) Not included Bottlenose dolphins Vessel noise and presence Insufficient data for this analysis Visual observations of individual foraging behavior No N/A
Bordino et al. (2002) Not included Franciscana dolphins ADDs Insufficient data for this analysis Insufficient data for this analysis No N/A
Williams et al. (2002) Not included Killer whales Vessel noise and presence Acoustic measurements of source levels but no estimates of RL Visual observations of movement and diving behavior No N/A
Cox et al. (2003) Not included Bottlenose dolphins ADDs Insufficient data for this analysis Visual observations of movement and diving behavior No N/A
Hastie et al. (2003) Not included Bottlenose dolphins Vessel noise and presence Insufficient data for this analysis Visual observations of movement and diving behavior No N/A
Lusseau (2003) Not included Bottlenose dolphins Vessel noise and presence Insufficient data for this analysis Visual observations of movement behavior No N/A
Foote et al. (2004) Not included Killer whales General increase in vessels Insufficient data for this analysis Insufficient data on individual exposures/responses for this analysis No N/A

 

Table 17

Number (in bold) of mid-frequency cetaceans (individuals and/or groups) reported as having behavioral responses to nonpulses; responses were categorized into 10-dB RL bins, ranked by severity of the behavioral response (see Table 4 for severity scaling), and combined with other observations having the same RL/severity score. A summary of the individual studies included in this table is given in the “Mid-Frequency Cetaceans/Nonpulses (Cell 6)” section of this chapter. Parenthetical subscripts indicate the reference reporting the observations as listed in Table 16.

Received RMS sound pressure level (dB re: 1 μPa)
Response score 80 to <90 90 to <100 100 to <110 110 to <120 120 to <130 130 to <140 140 to <150 150 to <160 160 to <170 170 to <180 180 to <190 190 to <200
9                        
8   1.0(3) 7.0(3)   5.0(2)   1.0(7)       5.0(13) 1.5(13)
7                        
6       3.0(2,10) 1.0(2)       1.0(9) 6.0(12)    
5         1.0(11)              
4       1.0(4) 2.0(4)              
3 5.0(1)   4.0(3,5) 134(4,6) 1.0(4)              
2       15.0(2,3,8)                
1     1.0(4) 1.0(2,3) 1.0(2,4)              
0     8.0(3,4) 2.0(2,4) 1.0(2,4)   1.0(2)       3.0(13) 1.5(13)

 

Table 18

Summary of behavioral responses of high-frequency cetaceans exposed to nonpulses (Cell 9) by type of sound source, available acoustic metrics, description of behavioral response (by individual and/or group), and a summary of corresponding severity score(s); specific severity scores for each study are given in Table 19 and more details are given in Appendix C. Exposure RLs are given in dB SPL, which are RMS sound pressure levels (dB re: 1 μPa).

Study Reference
number
(for Table 19)
Subject Species Sound source Type of acoustic
measurements
Type of individual and/or group behavioral responses Study included
in severity
scale
Summary of severity
scale analysis
(see Table 19)
Culik et al. (2001) 1 Harbor porpoises (wild) PICE pinger RL estimates based on source and environmental characteristics Visual observations of individual and group movements and behavioral patterns before and following deployment Yes Exposure RLs 80-120 dB SPL; response severity score: 0 & 6
Olesiuk et al. (2002) 2 Harbor porpoises (wild) Airmar® AHDs RL estimates based on source and environmental characteristics Visual observations of individual and group movements and behavioral patterns before and following deployment Yes Exposure RLs 140-160 dB SPL; response severity score: 6
Johnston (2002) 3 Harbor porpoises (wild) Airmar® AHDs RL estimates based on source and environmental characteristics Visual observations of individual and group movements and behavioral patterns before and following deployment Yes Exposure RLs 120-130 dB SPL; response severity scores: 0 & 6
Kastelein et al. (1997) 4 Harbor porpoises (captive) Various nonpulse sounds (laboratory) Calibrated RL measurements made in situ within test enclosure Visual observations of movement, respiration, and behavior in laboratory conditions Yes Exposure RLs 80-120 dB SPL; response severity scores: 0, 4 & 6
Kastelein et al. (2000) 5 Harbor porpoises (captive) Various nonpulse sounds (laboratory) Calibrated RL measurements made in situ within test enclosure Visual observations of movement, respiration, and behavior in laboratory conditions Yes Exposure RLs 90-120 dB SPL; response severity scores: 0 & 6
Kasteleinet al. (2005) 6 Harbor porpoises (captive) Various nonpulse sounds (laboratory) Calibrated RL measurements made in situ within test enclosure Visual observations of movement, respiration, and behavior in laboratory conditions Yes Exposure RLs 90-120 dB SPL; response severity scores: 0 & 6
Kastelein et al. (2006a) 7 Harbor porpoises (captive) Various nonpulse sounds (laboratory) Calibrated RL measurements made in situ within test enclosure Visual observations of movement, respiration, and behavior in laboratory conditions Yes Exposure RLs 100-120 dB SPL; response severity scores: 0 & 6
Kraus et al. (1997) Not included Harbor porpoises (wild) Dukane® pingers Insufficient data for this analysis Measurements of by-catch rates in commercial fisheries No N/A
Taylor et al. (1997) Not included Harbor porpoises (wild) General nonpulse sounds Review analysis Review analysis No N/A
Johnston & Woodley (1998) Not included Harbor porpoises (wild) Various AHDs Insufficient data for this analysis Visual observations of “exclusion” zones No N/A
Cox et al.(2001) Not included Harbor porpoises (wild) Various ADDs Insufficient data for this analysis Visual observations of “exclusion” zones No N/A
Kastelein et al. (2001) Not included Harbor porpoises (captive) Various nonpulse sounds (laboratory) Calibrated RL measurements made in situ near areas of exposure Aerial observations of individuals; movement and respiration patterns during and without airguns No N/A
Barlow & Cameron (2003) Not included Harbor porpoises (wild) Various ADDs Insufficient data for this analysis Measurements of by-catch rates in commercial fisheries No N/A
Koschinski et al. (2003) Not included Harbor porpoises (wild) Simulated wind turbine noise Calibrated source-level measurements made but insufficient data on RL Visual monitoring of general distribution patterns No N/A

 

Table 19

Number (in bold) of high-frequency cetaceans (individuals and/or groups) reported as having behavioral responses to nonpulses; responses were categorized into 10-dB RL bins, ranked by severity of the behavioral response (see Table 4 for severity scaling), and combined with other observations having the same RL/severity score. A summary of the individual studies included in this table is given in the “High-Frequency Cetaceans/Nonpulses (Cell 9)” section of this chapter. Parenthetical subscripts indicate the reference reporting the observations as listed in Table 18.

Received RMS sound pressure level (dB re: 1 μPa)
Response score 80 to <90 90 to <100 100 to <110 110 to <120 120 to <130 130 to <140 140 to <150 150 to <160 160 to <170 170 to <180 180 to <190 190 to <200
9                        
8                        
7                        
6 0.3(4) 0.3(4) 0.9(1, 2, 4, 5, 6, 7) 3.3(1,2,4,5,6,7) 1.0(3,7)   52.1(2) 9.3(2) 4.6(2)      
5                        
4     0.1 (4) 0.1 (4)                
3                        
2                        
1                        
0   12.8 (1,5) 23.1 (1,2,5,6) 0.4 (4,7) 0.1 (7) 0.3 (3)            

 

Table 20

Summary of behavioral responses by different species of pinnipeds in water exposed to nonpulses (Cell 12) by type of sound source, available acoustic metrics, description of behavioral response (by individual and/or group), and a summary of corresponding severity score(s); specific severity scores for each study are given in Table 21 and more details are given in Appendix C. Exposure RLs are given in dB SPL, which are RMS sound pressure levels (dB re: 1 μPa).

Study Reference
number
(for Table 21)
Subject Species Sound source Type of acoustic
measurements
Type of individual and/or group behavioral responses Study included
in severity
scale
Summary of severity
scale analysis
(see Table 21)
Jacobs & Terhune
(2002)
1 Harbor Seals Airmar dB plus II AHD RLs measured in situ in areas where individuals observed Visual observations of individuals and groups of seals; movement and behavioral patterns during and without AHDs Yes Exposure RLs 120-130 dB SPL; response severity score: 0
Costa et atl.
(2003)
2 Elephant seals ATOC (see Appendix B) RLs measured using calibrated archival tags in situ on individuals during exposure Archival tags placed on animals resulted in detailed quantitative measures of individual diving behavior, reponses, and exposure RLs in well-characterized contexts Yes Exposure RLs 110-140 dB SPL; response severity scores: 0, 3 & 4
Kastelein et al.
(2006b)
3 Harbor seals Various non-pulse sounds used in underwater data communications Calibrated RL measurements made in situ within experimental enclosure Individual subject positions and the mean number of surfacing behaviors during control and exposure intervals Yes Exposure RLs 80-110 dB SPL; response severity scores: 0 & 6
Frost & Lowry (1988) Not included Ringed seals Underwater drilling sounds Insufficient data for this analysis Insufficient data for this analysis No N/A
Richardson et al. (1990b, 1991) Not included Ringed and bearded seals Underwater drilling sounds Insufficient data for this analysis Insufficient data for this analysis No N/A
Norberg & Bain (1994) Not included California sea lions Cascade Applied Sciences AHDs Calibrated acoustic measurements taken around arrays of the devices Insufficient data on individual responses for this analysis No N/A
Norberg
(2000)
Not included harbor seals HAD Insufficient data for this analysis Insufficient data for this analysis No N/A
Yurk (2000) Not included Harbor seals AHD Insufficient data for this analysis Insufficient data for this analysis No N/A
Koschinski et al. (2003) Not included Harbor seals Simulated wind turbine noise RLs measured in situ in areas where individuals observed Insufficient data on individual responses for this analysis No N/A
Moulton et al. (2003) Not included Ringed seals Construction noise Insufficient data for this analysis Insufficient data on individual responses for this analysis No N/A

 

Table 21

Number (in bold) of pinnipeds in water (individuals and/or groups) reported as having behavioral responses to nonpulses; responses were categorized into 10-dB RL bins, ranked by severity of the behavioral response (see Table 4 for severity scaling), and combined with other observations having the same RL/severity score. A summary of the individual studies included in this table is given in the “Pinnipeds in Water/Nonpulses (Cell 12)” section of this chapter. Parenthetical subscripts indicate the reference reporting the observations as listed in Table 20.

Received RMS sound pressure level (dB re: 1 μPa)
Response score 80 to <90 90 to <100 100 to <110 110 to <120 120 to <130 130 to <140 140 to <150 150 to <160 160 to <170 170 to <180 180 to <190 190 to <200
9                        
8                        
7                        
6     1.0 (3)                  
5                        
4         1.0 (2) 5.0 (2)            
3         1.0 (2) 2.0 (2)            
2                        
1                        
0 1.0 (3) 1.0 (3) 1.0 (2) 5.0 (1,2)                

 

Table 22

Summary of behavioral responses by different species of pinnipeds in air exposed to nonpulses (Cell 15) by type of sound source, available acoustic metrics, description of behavioral response (by individual and/or group), and a summary of corresponding severity score(s); specific severity scores for each study are given in table 23 and more details are given in Appendix C. Exposure RLs are given in dB SPL, which are RMS sound pressure levels (dB re: 20 μPa).

Study Reference number (for Table 23) Subject species Sound source Type of acoustic measurements Type of individual and/or group behavioral responses Study included in severity scale Summary of severity scale analysis (see Table 23)
Thorson et al. (1999) 1 harbor Seals, northern elephant seals, California sea lions, and northern fur seals Athena 2 IKONOS-1 missile launch RLs measured in situ in and around breeding rookeries Visual observations of movement and behavior of individuals in breeding rookeries before, during, and after rocket launches Yes Exposure RLs 110-120 dB SPL; response severity score: 6
Thorson et al. (2000b) 2 Harbor seals, northern elephant seals, and California sea lions Titan IV B-28 missile launch RLs measured in situ in and around breeding rookeries Visual observations of movement and behavior of individuals in breeding rookeries before, during, and after rocket launches Yes Exposure RLs 60-70 and 110-120 dB SPL; response severity scores: 0 & 6
Berg et al. (2002) 3 Harbor seals Titan IV B-28 missile launch RLs measured in situ in and around breeding rookeries Visual observations of movement and behavior of individuals in breeding rookeries before, during, and after rocket launches Yes Exposure RLs 110-120 dB SPL; response severity socre: 6
Allen et al. (1984) Not include Harbor seals Aerial vessel noise and presence Insufficient data for this analysis Insufficient data for this analysis No N/A
Gentry et al. (1990) Not included Northern fur seals Underground explosions and quarrying operations Insufficient data for this analysis Insufficient data for this analysis No N/A
Suryan & Harvey (1998) Not included Harbor seals Aerial vessel noise and presence Insufficient data for this analysis Insufficientdata for this analysis No N/A
Thorson et al. (1998) Not included Harbor seals Titan IV A-18 missile launch RLs measured in situ in and around breeding rookeries Insufficient data for this analysis No N/A
Born et al. (1999) Not included Ringed seals Aircraft noise and presence Insufficient data for this analysis Insufficient data for this analysis No N/A
Thorson et al. (2000a) Not included Harbor Seals Titan II G-13 missile launch RLs measured in situ in and around breeding rookeries Insufficient data for this analysis No N/A
Berg et al. (2001) Not included California sea lions and northern elephant seals Delta II EO-1 missile launch RLs measured in situ in and around breeding rookeries Insufficient data for this analysis No N/A
Moulton et al. (2002) Not included Ringed seals Industrial equipment noise & presence Insufficient data for this analysis Insufficient data for this analysis No N/A
Holst et al. (2005a, 2005b) Not included Harbor seals, California sea lions, and northern elephant seals Small- and mid-sized missile launches RLs measured near observed pinnipeds, including peak, RMS, SEL, and duration Visual observations of animal presence and distribution before launches and behavior during and following launches No N/A

 

Table 23

Number (in bold) of pinnipeds in air (individuals and/or groups) reported as having behavioral responses to nonpulses; responses were categorized into 10-dB RL bins, ranked by severity of the behavioral response (see Table 4 for severity scaling), and combined with other observations having the same RL/severity score. A summary of the individual studies included in this table is given in the “Pinnipeds in Air/Nonpulses (Cell 15)” section in this chapter. Parenthetical subscripts indicate the reference reporting the observations as listed in Table 22.

Received RMS sound pressure level (dB re: 20 μPa)
Response score 50 to <60 60 to <70 70 to <80 80 to <90 90 to <100 100 to <110 110 to <120
9              
8              
7              
6             1.0 (1,2,3)
5              
4              
3              
2              
1              
0   1.0 (2)          

 

Table 24

Research recommendations in various subject areas needed to enhance future marine mammal noise exposure criteria (as discussed in Chapter 5)

Research topic General description Critical information needs
Acoustic measurements of relevant sound sources Detailed measurements needed of source levels, frequency content, and radiated sound fields around intense and/or chronic noise sources. Comprehensive, calibrated measurements of the properties of human-generated sound sources, including frequency-dependent propagation and received characteristics in different environments.
Ambient noise measurements Systematic measurements of underwater ambient noise are needed to quantify how human activities are affecting the acoustic environment. Comprehensive, calibrated measurements of ambient noise, including spectral, temporal, and directional aspects, in different oceanic environments; ambient noise “budgets” indicating relative contribution of natural and anthropogenic sources and trends over time.
“Absolute” hearing measurements Audiometric data are needed to determine functional bandwidth, species and individual differences, dynamic hearing ranges, and detection thresholds for realistic biological stimuli. Carefully controlled behavioral and electrophysiological measurements of hearing sensitivity vs frequency for more individuals and species, particularly for high-priority species, such as beaked whales and mysticetes. Also, detection thresholds for complex biological signals.
Auditory scene analysis Measurements to determine the sophisticated perceptual and processing capabilities of marine mammals that enable them to detect and localize sources in complex, 3-D environments. Measurements of stream segregation, spatial perception, multidimensional source localization, frequency discrimination, temporal resolution, and feedback mechanisms between sound production and hearing systems.
Marine mammal behavioral responses to sound exposure Measurements of behavioral reactions to various sound types are needed, including all relevant acoustic, contextual, and response variables. Carefully constructed observational and exposure experiments that consider not only RL but also source range, motion, signal-to-noise ratio, and detailed information on receivers, including baseline behavior, prior experience with the sound, and responses during exposure.
Effects of sound exposure on marine mammal hearing: masking, TTS, and PTS Continued effort is needed on the simultaneous and residual physiological effects of noise exposure on marine mammal hearing. Masked hearing thresholds for simple stimuli in more species and individuals, as well as complex biological signals and realistic maskers; allowance for directional effects; comparative data on TTS-onset and growth in a greater number of species and individuals for nonpulse and pulsed anthropogenic sources; recovery functions after exposures and between repeated exposures.
Effects of sound exposure on marine mammal non-auditory systems Physiological measurements are needed for both acute and chronic sound exposure conditions to investigate effects on non-auditory systems. Various baseline and exposure-condition measurements, including nitrogen saturation levels; bubble nuclei; the formation of hemorrhages, emboli, and/or lesions; stress hormones; and cardiovascular responses to acute and chronic noise exposure.
Particularly sensitive species: beaked whales Baseline and exposure data on these poorly understood taxa to assess their apparent sensitivity to certain anthropogenic sound sources. Various studies, including measurements and modeling related to (1) hearing sensitivity, (2) diving and vocalization parameters, (3) tissue properties, (4) gas/fat emboli formation and significance, (5) advanced detection capabilities for localizing and tracking them, and (6) behavioral reactions to various anthropogenic and natural sound sources.
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