[Federal Register Volume 78, Number 249 (Friday, December 27, 2013)]
[Notices]
[Pages 78822-78823]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-30951]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XC969


Draft Guidance for Assessing the Effects of Anthropogenic Sound 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

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; request for comments.

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SUMMARY: 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availability of draft guidance for assessing the effects of 
anthropogenic sound on marine mammal species under NOAA's jurisdiction. 
The guidance provides updated received levels, or thresholds, above 
which individual marine mammals are predicted to experience changes in 
their hearing sensitivity (either temporary or permanent) for all 
underwater anthropogenic sound sources. NOAA solicits public comment on 
the draft guidance.

DATES: Comments must be received by January 27, 2014.

ADDRESSES: The draft guidance is available in electronic form via the 
Internet at http://www.nmfs.noaa.gov/pr/acoustics/.
    You may submit comments, identified by [NOAA-NMFS-2013-0177], by 
any of the following methods:
    Electronic Submissions: Submit all electronic public comments via 
the Federal eRulemaking Portal http://www.regulations.gov.
    Mail: Send comments to: Chief, Marine Mammal and Sea Turtle 
Conservation Division, Office of Protected Resources, National Marine 
Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910-
3226, Attn: Acoustic Guidance.
    Instructions: All comments received are a part of the public record 
and will generally be posted to http://www.regulations.gov without 
change. All Personal Identifying Information (for example, name, 
address, etc.) voluntarily submitted by the commenter may be publicly 
accessible. Do not submit Confidential Business Information or 
otherwise sensitive or protected information.
    NMFS will accept anonymous comments (enter N/A in the required 
fields, if you wish to remain anonymous). You may submit attachments to 
electronic comments in Microsoft Word, Excel, WordPerfect, or Adobe PDF 
file formats only.
    NMFS will hold a public meeting and webinar to inform interested 
parties and solicit comments on the draft guidance document. The 
meeting will be held on January 14, 2014, from 2 p.m. to 5 p.m. (EST) 
at the NOAA Silver Spring Metro Center Complex, NOAA Science Center, 
1301 East-West Highway, Silver Spring, MD 20910. This meeting is 
accessible to people with disabilities. Requests for sign language 
interpretation or other auxiliary aids should be directed to Amy 
Scholik-Schlomer, (301) 427-8449 (voice), (301) 713-0376 (fax), or 
[email protected] at least five days before the scheduled meeting 
date. Information on how to register for the online webinar will be 
posted on via the Internet at http://www.nmfs.noaa.gov/pr/acoustics/ 
after January 1, 2014.

FOR FURTHER INFORMATION CONTACT: Amy Scholik-Schlomer, Office of 
Protected Resources, 301-427-8449, [email protected].

SUPPLEMENTARY INFORMATION: The National Marine Fisheries Service and 
the National Ocean Service (referred collectively here as the National 
Oceanic and Atmospheric Administration (NOAA)), have developed draft 
guidance for assessing the effects of anthropogenic sound on marine 
mammal species under NOAA's jurisdiction. Specifically, the guidance 
identifies the received levels, or thresholds, above which individual 
marine mammals are predicted to experience changes in their hearing 
sensitivity (either temporary or permanent) for all underwater 
anthropogenic sound sources. This is the first time NOAA has presented 
this information in a single, comprehensive document. This guidance is 
intended to be used by NOAA analysts and managers and other relevant 
user groups and stakeholders, including other federal agencies, when 
seeking to determine whether and how their activities are expected to 
result in particular types of impacts to marine mammals via acoustic 
exposure. This document outlines NOAA's updated acoustic threshold 
levels and describes in detail how the thresholds were developed and 
how they will be updated in the future.
    NOAA has compiled, interpreted, and synthesized the best available 
science to produce updated acoustic threshold levels for the onset of 
both temporary

[[Page 78823]]

(TTS) and permanent hearing threshold shifts (PTS). These thresholds 
replace those currently in use by NOAA. Updates include a protocol for 
estimating PTS and TTS onset levels for impulsive (e.g., airguns, 
impact pile drivers) and non-impulsive (e.g., sonar, vibratory pile 
drivers) sound sources, the formation of marine mammal functional 
hearing groups (low-, mid-, and high-frequency cetaceans and otariid 
and phocid pinnipeds), and the incorporation of marine mammal auditory 
weighting functions into the calculation of thresholds. These acoustic 
threshold levels are presented using the dual metrics of cumulative 
sound exposure level and peak sound pressure level. This document 
addresses how to combine multiple datasets, as well as how to determine 
appropriate surrogates when data are not available. While the updated 
acoustic thresholds are more complex than those previously used by 
NOAA, they accurately reflect the current state of scientific knowledge 
regarding the characteristics of sound that have the potential to 
impact marine mammal hearing sensitivity. Given the specific nature of 
these updates, it is not possible to compare directly the updated 
acoustic threshold levels presented in this document with the 
thresholds previously used by NOAA.
    Although NOAA has updated the acoustic threshold levels from those 
previously used, and these changes may necessitate new methodologies 
for calculating impacts, the application of the thresholds in the 
regulatory context under applicable statutes (Marine Mammal Protection 
Act, Endangered Species Act, and National Marine Sanctuaries Act) 
remains consistent with past NOAA practice. It is important to note 
that these updated acoustic threshold levels do not represent the 
entirety of an impact assessment, but rather serve as one tool (in 
addition to behavioral impact thresholds, auditory masking assessments, 
evaluations to help understand the ultimate effects of any particular 
type of impact on an individual's fitness, population assessments, 
etc.), to help evaluate the effects of a proposed action on marine 
mammals and make findings required by our various statutes.
    The document is classified as a Highly Influential Scientific 
Assessment by the Office of Management and Budget. As such, independent 
peer review is required prior to broad public dissemination by the 
Federal Government. NOAA conducted a peer review of the updated 
acoustic threshold levels. Details of the peer review can be found 
within this document, and at the following Web site: http://www.nmfs.noaa.gov/pr/acoustics/.
    A summary of the updated acoustic threshold levels can be found in 
the main body of the document and additional details are provided in 
the appendices. Section I provides an introduction to the document and 
a description of how NOAA addressed uncertainty and data limitations. 
NOAA's updated acoustic threshold levels for onset of PTS and TTS for 
marine mammals exposed to underwater sound are presented in Section II. 
Section III describes how acoustic threshold levels are interpreted 
under NOAA's statutes. NOAA's plan for periodically updating acoustic 
threshold levels is presented in Section IV. More details on the marine 
mammal auditory weighting functions, the development of acoustic 
threshold levels, the peer review process, and a glossary of acoustic 
terms can be found in the appendices.
    NOAA particularly encourages the public to identify any additional 
datasets for inclusion in the assessment, and to comment on the 
appropriateness of the proposed accumulation period for the cumulative 
sound exposure metric and the proposed low-frequency auditory weighting 
function for which direct measurements of hearing sensitivity are not 
available.

    Dated: December 19, 2013.
Alan D. Risenhoover,
Director, Office of Sustainable Fisheries, performing the functions and 
duties of the Deputy Assistant Administrator for Regulatory Programs, 
National Marine Fisheries Service.
[FR Doc. 2013-30951 Filed 12-26-13; 8:45 am]
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