BOEM’S New SEIS for Chukchi Discusses Acoustic Criteria for Fish and Marine Mammals

The U.S. Bureau of Ocean Energy Management has published its Chukchi Sea Planning Area Oil and Gas Lease Sale 193 In the Chukchi Sea, Alaska Final Second Supplemental Environmental Impact Statement. This document includes extensive discussion of the effects of anthropogenic sound, including oil and gas seismic, on fish and marine mammals.  The discussion in this document may indicate BOEM’s current thinking on this issue.

For fish, the SEIS relies on Popper, et al., 2014, Sound Exposure Guidelines for Fishes and Sea Turtles: A Technical Report prepared by ANSI-Accredited Standards Committee S3/SC1 and registered with ANSI (2014); publication ASA S3/SC1.4 TR-2014; published by the Acoustical Society of America in collaboration with Springer. On page 226 of the SEIS, BOEM states:

“A more extensive science-based set of sound-exposure guidelines were recently developed (Popper et al., 2014) based on the various ways fish species detect sound. Guidelines are presented for the following sound sources: seismic airguns, pile driving, explosives, low and mid-frequency naval radar, shipping and other continuous sounds. These guidelines are interim, based on research to date on the effects of noise on fishes, and would be refined every five years, or sooner, as additional applicable research is published.

The sound exposure guidelines (level of exposure for onset of effects) for fish in relation to seismic airguns (Table 4-28) were derived from various sources, including research on pile-driving effects. Table 4-28 shows the cumulative sound exposure levels (SELcum) for mortality, potential mortal injury, and impairment. The effects on behavior are described qualitatively, which is sufficient to inform the ensuing analysis.

Sound exposure guidelines (Popper et al., 2014) for shipping and other continuous noise are shown in (Table 4-29). Qualitative effects are presented for mortality, potential mortal injury, impairment, and behavior for all fish; the exception is quantitative guidelines that are available for impairment in fish with a swim bladder tied to hearing.

These 2014 guidelines by Popper et al. provide an important step in understanding and assessing the effects of sound on fish.”

SEIS Tables 4-28 and 4-29, which provide BOEM’s fish sound exposure guidelines, are attached as Appendix A to this article.

For marine mammals, BOEM relies on Ciminello, et al., 2012, Determination of Acoustic Effects on Marine Mammals and Sea Turtles for the Atlantic Fleet Training and Testing Environmental Impact Statement/Overseas Environmental Impact Statement. NUWC-NPT Technical Report 12,071. Newport, Rhode Island: Naval Undersea Warfare Center Division. The SEIS states on page 275:

“Ciminello et al. (2012) analyzed the effects of noise on marine mammals using existing data and compiled noise criteria and threshold tables of Non-impulsive (continuous) and Impulsive noise for marine mammals (Tables 4-45 and 4-46).”

BOEM’s Tables 4-45 and 4-46, which provide BOEM’s marine mammal “noise criteria and threshold tables,” are attached as Appendix B to this article.

These sound criteria are implemented in part through mandatory shut downs when marine mammals are within a specified radius of the seismic vessel. BOEM explains on page C-2 of Appendix I of the SEIS that:

“Shutdown / power down procedures for vessels and other equipment that could operate within habitat used by marine mammals. Such procedures usually require that the equipment be shut down or powered down if a marine mammal comes within a specified radius. The purpose of this measure is to avoid injury, and to reduce the likelihood of other adverse impacts to marine mammals from exposure to high noise levels. NMFS and USFWS use the best science available to recommend appropriate sound thresholds (dB levels) to avoid/minimize adverse impacts to marine mammals under their jurisdictions. The distance from the sound source associated with those thresholds is established through acoustic modeling or onsite verification tests.”

BOEM’s SEIS is available online by clicking here.

Click Appendix A or Appendix B for the accompanying materials.

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