Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 7 (6), e38968

Threshold for Onset of Injury in Chinook Salmon From Exposure to Impulsive Pile Driving Sounds


Threshold for Onset of Injury in Chinook Salmon From Exposure to Impulsive Pile Driving Sounds

Michele B Halvorsen et al. PLoS One.


The risk of effects to fishes and other aquatic life from impulsive sound produced by activities such as pile driving and seismic exploration is increasing throughout the world, particularly with the increased exploitation of oceans for energy production. At the same time, there are few data that provide insight into the effects of these sounds on fishes. The goal of this study was to provide quantitative data to define the levels of impulsive sound that could result in the onset of barotrauma to fish. A High Intensity Controlled Impedance Fluid filled wave Tube was developed that enabled laboratory simulation of high-energy impulsive sound that were characteristic of aquatic far-field, plane-wave acoustic conditions. The sounds used were based upon the impulsive sounds generated by an impact hammer striking a steel shell pile. Neutrally buoyant juvenile Chinook salmon (Oncorhynchus tshawytscha) were exposed to impulsive sounds and subsequently evaluated for barotrauma injuries. Observed injuries ranged from mild hematomas at the lowest sound exposure levels to organ hemorrhage at the highest sound exposure levels. Frequency of observed injuries were used to compute a biological response weighted index (RWI) to evaluate the physiological impact of injuries at the different exposure levels. As single strike and cumulative sound exposure levels (SEL(ss), SEL(cum) respectively) increased, RWI values increased. Based on the results, tissue damage associated with adverse physiological costs occurred when the RWI was greater than 2. In terms of sound exposure levels a RWI of 2 was achieved for 1920 strikes by 177 dB re 1 µPa(2)⋅s SEL(ss) yielding a SEL(cum) of 210 dB re 1 µPa(2)⋅s, and for 960 strikes by 180 dB re 1 µPa(2)⋅s SEL(ss) yielding a SEL(cum) of 210 dB re 1 µPa(2)⋅s. These metrics define thresholds for onset of injury in juvenile Chinook salmon.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.


Figure 1
Figure 1. The HICI-FT in the horizontal and vertical positions.
A) The HICI-FT in the vertical position for loading fish into the acrylic chamber. The top shaker is detached from the tube and is surrounded by gray PVC to protect it from the water in the acrylic chamber. B) During Treatments the HICI-FT is in the horizontal position. The shaker is labeled. The red structure is the supporting buggy, the white PVC pipes drain the water, and the grey hoses are part of the shaker cooling system.
Figure 2
Figure 2. Two of the pile driving sound signals used in the study.
In each figure pair, the upper image shows the signal time-domain normalized in amplitude, while the lower panel shows the power spectral density.
Figure 3
Figure 3. Examples of injuries.
Mild injuries are A) eye hemorrhage, B) and C) fin hematoma; Moderate injuries are D) liver hemorrhage and E) bruised swim bladder; Mortal injuries are F) intestinal hemorrhage and G) kidney hemorrhage.
Figure 4
Figure 4. Individual RWI values by SELcum for 1920 and 960 impulses and controls.
Figure 5
Figure 5. Individual RWI values by SELss for 1920 and 960 impulses and controls.
Figure 6
Figure 6. Frequency of barotrauma injury occurrence per fish.
The number of test fish (z-axis) with number of unweighted-barotrauma injuries (x-axis) by each Treatment (y-axis) which is in order of SELcum values (see Table 1). For example, in the most severe exposure (Treatment 1 =  T1, see Table 1 for each Treatment’s metrics), 1 fish had 13 injuries, and 10 fish had 8 injuries. Similarly, for the least severe exposure (T11), 6 fish had 1 injury, and 24 fish had 0 injuries.
Figure 7
Figure 7. Number of injuries within each injury category.
Within each Treatment bin is a representation of the number of injuries for each injury category of Mortal, Moderate, and Mild. The y-axis is number of injuries, x-axis is each Treatment (exposure and control: ex., T1 =  Treatment 1 Exposure; T1 Ctrl  =  Treatment 1 Control).
Figure 8
Figure 8. SELcum vs. ln (RWI+1) for all Treatments.
Solid line shows predicted ln(RWI+1) values for 960 strikes and dashed line for 1920 strikes. Green squares denote the 960 strikes and red diamonds denote the 1920 strikes.
Figure 9
Figure 9. Contour plots of experimental space.
The background layer plots the SELcum contours (blue dashed lines represented by SELcum  =  SELss +10log10 (Number of impulses)) by SELss, and number of impulses within the Treatment range. The solid black lines labeled 1–10 are a contour plot of the log transformed RWI which illustrates value increases as SELss increases; represented by RWI =  exp(−30.050+0.149 * SELcum –0.000171 * Number of strikes )-1. The upper black horizontal line indicates the 1920 strike-line, and the bottom black horizontal line indicates the 960 strike-line. Together, the plots shows where the RWI contours fall over the SELcum range and SELss range in relation to number of impulses.

Similar articles

See all similar articles

Cited by 9 PubMed Central articles

See all "Cited by" articles


    1. Nedwell J, Workman R, Parvin SJ. The assessment of likely levels of piling noise at Greater Gabbard and comparison with background noise, including piling noise measurements made at Kentish Flats. Report # 633R0115. Oxford: For David Bean, PMSS. pp 1–45. 2005.
    1. Nedwell JR, Turnpenny AWH, Lovell JM, Edwards B. An investigation into the effects of underwater piling noise on salmonids. Journal of the Acoustical Society of America. 2006;120:2550–2554. - PubMed
    1. Abbott R, Reyff J, Marty G. Final Report: Monitoring the effects of conventional pile driving on three species of fish. San Rafael, CA: Strategic Environmental Consulting, Inc. pp 1–137. 2005.
    1. Caltrans. Biological Assessment for the Benicia Martinez new bridge project for NOAA Fisheries. California Department of Transportation. pp 1–24. 2002.
    1. Caltrans. Necropsy and Histopathology of Steelhead Trout Exposed to Steel Pile Driving at the Mad River Bridges, U.S. Highway 101, July 2009. Prepared by G. D. Marty, DVM, Ph.D., Fish Pathology Services, Abbotsford, British Columbia, Canada. 2010.

Publication types