NOAA Fisheries, per approval of the Secretary of Commerce, is releasing the 2018 Revision to: Technical Guidance for Assessing the Effects of Anthropogenic Sound on Marine Mammal Hearing – Underwater Thresholds for Onset of Permanent and Temporary Threshold Shifts (NOAA Technical Memorandum NMFS-OPR-59) in relation to section 10 of the Presidential Executive Order (EO) 13795, “Implementing an America-First Offshore Energy Strategy.” The Notice of Availability for the 2018 Revision to: Technical Guidance is available here – (https://www.federalregister.g ov/documents/2018/06/21/2018-13313/guidance-2018-revision-to -technical-guidance-for-assessing-effects-of-anthropogenic-sound-on-marine) and will publish on Thursday, June 21. . The Technical Guidance is a science-based document that compiles, interprets, and synthesizes scientific literature to produce updated acoustic thresholds for assessing the effects of underwater sound on marine mammal hearing. It is intended for use by NOAA Fisheries’ managers and other relevant user groups/stakeholders, when seeking to determine whether and how their activities are expected to result in hearing impacts to marine mammals via acoustic exposure. The Technical Guidance does not represent the entirety of NOAA Fisheries’ comprehensive effects analysis but rather serves as one tool to help evaluate a proposed action. We recommend its use but note that user groups/stakeholders are not required to use the Technical Guidance; other scientifically rigorous methods are acceptable. We completed a 45-day public comment period and hosted a Federal Agencies’ forum to gather feedback to inform our revision of the Technical Guidance under section 10 of E.O. 13795. The comments received during the Technical Guidance review affirmed that the Guidance is based on the best available science while also providing suggestions to improve its implementation. No commenter or federal agency suggested rescinding the document. The acoustic thresholds for onset of permanent threshold shift (PTS) and temporary threshold shifts (TTS) in marine mammal hearing for all sound sources in the 2018 Revision (NOAA Technical Memorandum NMFS-OPR-59) will remain the same as the 2016 Technical Guidance. Nevertheless, this 2018 revision of the Technical Guidance (NOAA Technical Memorandum NMFS-OPR-59) addresses implementation and facilitates its use applicants, thereby further advancing the policy in section 2 of E.O. 13795. To accompany the revised Technical Guidance (NOAA Technical Memorandum NMFS-OPR-59), NOAA Fisheries is issuing an updated User Spreadsheet tool with additional capabilities for applicants and a new companion User Manual for the Spreadsheet tool that provides detailed instructions, definitions, and appropriate defaults to use when data are unavailable. The 2018 Revision to the Technical Guidance (NOAA Technical Memorandum NMFS-OPR-59), as well as the updated User Spreadsheet tool and the new companion User Manual will be available in electronic form via the Internet at https://www.fisheries.noaa.gov/national/marine-mammal-pro tection/marine-mammal-acoustic-technical-guidance. We will continue to improve this Technical Guidance using the best available science and refine the User Manual based on your input. NOAA Fisheries plans to submit the User Manual for the Spreadsheet tool for public comment (anticipated later in 2018) to gain your input and inform future versions of the User Manual. Additionally, NOAA Fisheries will re-evaluate implementation of the 24-h accumulation period in the Technical Guidance by convening a working group to investigate means for deriving more realistic accumulation periods (anticipated later in 2018). NOAA Fisheries will also convene a working group (anticipated later in 2018) to explore the impacts of sound on baleen whale hearing and incorporate recommendations from this working group in future updates to the Technical Guidance. Thank you for your interest in the Technical Guidance. For more information, please contact Amy Scholik-Schlomer (amy.scholik@noaa.gov or 301 427-8449). *Amy R. Scholik-Schlomer, Ph.D.* Fishery Biologist (Protected Resources Acoustic Coordinator) NOAA's National Marine Fisheries Service Office of Protected Resources Marine Mammal and Sea Turtle Conservation Division 1315 East-West Hwy. SSMC3, Rm. 13605 Silver Spring, MD 20910 (301) 427-8449 Email: *Amy.Scholik@noaa.gov <Amy.Scholik@noaa.gov>http://www.nmfs.noaa.gov/pr/acoustics/ <http://www.nmfs.noaa.gov/pr/acoustics/>*