Marine Mammal Acoustic Technical Guidance
NMFS Acoustic Thresholds, Tools, and Technical Guidance
NMFS Acoustic Thresholds and Tools
- Summary of Marine Mammal Protection Act Acoustic Thresholds
- Summary of Endangered Species Act Acoustic Thresholds (Fishes and Sea Turtles)
- Introduction to NMFS’s Multi-Species Pile Driving Calculator and Associated Multi-Species Pile Driving Calculator
- Recommendation for High-resolution Geophysical Source & Transmission Loss Analysis and Associated Level B Harassment Isopleth Calculator
- Acoustic Guidance for Assessment of Down-the-Hole (DTH) Systems
- 2018 Revision to Technical Guidance for Assessing the Effects of Anthropogenic Sound on Marine Mammal Hearing (pdf, 178 pages)
NMFS Technical Guidance
Public Comment Period: Updated Technical Guidance (2024)
NMFS is in the process of updating our current 2018 Revised Technical Guidance and is soliciting public comment via a 45-day public comment period, which opened on May 3, 2024 and closes on June 17, 2024. If you are interested in providing comments, please do so via Regulations.gov.
- Updated Technical Guidance for public comment (pdf, 192 pages)
- DRAFT optional User Spreadsheet tool with Updated Technical Guidance thresholds
- NMFS is providing this DRAFT tool as a means for the public to better assess changes associated with the Updated Technical Guidance. The focus of the public comment period is not on this DRAFT tool.
- PLEASE NOTE: Until the Updated Technical Guidance completes its review process (Public Comment) and is finalized, the 2018 Revised Technical Guidance remains in place. Thus, this DRAFT tool should not be used for any analyses until the Updated Technical Guidance is finalized.
Purpose of the Updated Technical Guidance
The Updated Technical Guidance (PDF,192 pages) provides thresholds for onset of auditory injury (AUD INJ) and temporary threshold shifts (TTS) in marine mammal hearing for all underwater and airborne sound sources based on updated data. It is intended to be used by NOAA analysts and managers, other federal agencies, and other relevant user groups/stakeholders to better predict how a marine mammal’s hearing will respond to sound exposure underwater and in-air.
To develop these thresholds, NOAA Fisheries compiled, interpreted, and synthesized best available information on the effects of anthropogenic sound on marine mammals' hearing, as well as developed a method for updating these levels through a systematic, transparent process. The Updated Technical Guidance outlines NOAA Fisheries' acoustic thresholds and describes in detail how the thresholds were developed and how they will be updated in the future.
Review Process for Updated Technical Guidance
The Updated Technical Guidance has completed a Peer Review (October/November 2022) and Federal Agency Preview (May/June 2023).
PLEASE NOTE: Until the Updated Technical Guidance completes its review process (Public Comment) and is finalized, the 2018 Revised Technical Guidance remains in place and should continue to be used.
Revised Technical Guidance (2018)
2017 Presidential Executive Order 13795
Section 10 of the Presidential Executive Order 13795, Implementing an America-First Offshore Energy Strategy (April 28, 2017) called for a review of the 2016 Technical Guidance. To assist the Secretary of Commerce in his review under EO 13795, NOAA Fisheries conducted a 45-day public comment period that opened on May 31, 2017 and closed July 17, 2017 (82 FR 24950) and held a meeting with federal agencies (September 25, 2017). Comments received are available on regulations.gov. Additional information on the review process under Executive Order 13795 can be found in Appendix C of the 2018 Revised Technical Guidance.
Revised Technical Guidance (2018)
NOAA Fisheries’ evaluation of comments received during this review affirms that the Technical Guidance is based upon the best available science. The threshold levels established in the 2016 Guidance will remain the same. Applicants when referring to Technical Guidance or its associated optional user tools should refer to the 2018 revised version of this document, not the 2016 version of the Technical Guidance.
NOAA Fisheries has revised the Technical Guidance to address implementation concerns and facilitate its use by applicants, thereby further advancing the intent of E.O. 13795. Specifically, we updated the optional User Spreadsheet tool to provide more capabilities for applicants and developed a new instructional manual for this optional tool. We will continue to coordinate with Federal Agencies to advance our understanding of the impacts of sound on marine mammals.
In 2018, NOAA Fisheries held a 45-day public comment period (83 FR 48291) for user feedback to help improve the usability of our optional User Spreadsheet Tool and Instruction Manual for User Spreadsheet Tool. Comments received are available on regulations.gov. In July 2020, NOAA Fisheries made some technical updates to the optional User Spreadsheet tool, as well as developed a web version of the tool (Web Calculator Tool) and corresponding instruction manuals.
In association with this 2018 public comment period, the International Association for Geophysical Contractors (IAGC) submitted their final comments to NOAA Fisheries in late 2020 (IAGC Supplemental User Guide and IAGC Alternative Calculator). Based on recommendations where NOAA Fisheries concurs with IAGC, NOAA Fisheries made additional modifications to our optional User Spreadsheet tool and associated User Manual (December 2020).
Both tools will be updated as new science or information becomes available. NOAA Fisheries plans to evaluate these tools on a regular basis (before the end of each calendar year) to incorporate any necessary updates.
- 2018 Revision to Technical Guidance for Assessing the Effects of Anthropogenic Sound on Marine Mammal Hearing (PDF,178 pages)
- User Spreadsheet Tool (optional) (MS Excel) (Updated November 2021)
- Instruction Manual for User Spreadsheet Tool (optional) (PDF, 103 pages) (Updated December 2020)
- Web Calculator Tool (optional) (R-Shiny) (July 2020)
- Instruction Manual for Web Calculator Tool (PDF, 62 pages) (July 2020)
2016 Technical Guidance
The 2016 Technical Guidance underwent an internal review, three external peer reviews, a follow-up peer review, three public comment periods, and received informal input from key federal partners.
External Peer Reviews
More information about these peer reviews
Public Comment Periods
- First public comment period (2013/2024)
- Second public comment period (2015)
- Third public comment period (2016)
Comments received during all the public comment periods are available on regulations.gov.
Finalization of 2016 Technical Guidance
The 2016 Technical Guidance was finalized on August 4th, 2016 with publication of a Federal Register Notice (81 FR 51693).
For more information, please contact:
Amy R. Scholik-Schlomer
NMFS Protected Resources Acoustic Coordinator
1315 East West Highway
Silver Spring, MD 20910
(301) 427-8449
Amy.Scholik@noaa.gov