Draft Guidance for Assessing the Effects of Anthropogenic Sound on Marine Mammal Hearing-Acoustic Threshold Levels for Onset of Permanent and Temporary Threshold Shifts

The National Marine Fisheries Service (NMFS), on behalf of NMFS and the National Ocean Service (referred collectively here as the National Oceanic and Atmospheric Administration (NOAA)), announces the availability of a document containing proposed changes to its Draft Guidance for Assessing the Effects of Anthropogenic Sound on Marine Mammal Hearing. The Guidance provides updated received levels, or thresholds, at which individual marine mammals under NOAA's management authority are predicted to experience changes in their hearing sensitivity (either temporary or permanent) for all underwater anthropogenic sound sources. NOAA has re-evaluated and modified several parts of the Draft Guidance and is soliciting public comment on the proposed changes.