Voglio sapere a riguardo di…

30096

Federal Register / Vol. 86, No. 106 / Friday, June 4, 2021 / Proposed Rules
information regarding the proposed take.
Biologically Important Areas In 2015, NOAAs Cetacean Density and Distribution Mapping Working Group identified Biologically Important Areas BIAs for 24 cetacean species, stocks, or populations in seven regions US East Coast, Gulf of Mexico, West Coast, Hawaiian Islands, Gulf of Alaska, Aleutian Islands and Bering Sea, and Arctic within U.S. waters through an expert elicitation process. BIAs are reproductive areas, feeding areas, migratory corridors, and areas in which small and resident populations are concentrated. BIAs are region-, species-, and time-specific. A
description of the types of BIAs found within NEFSC fishery research areas follows:

Reproductive Areas: Areas and months within which a particular species or population selectively mates, gives birth, or is found with neonates or other sensitive age classes.
Feeding Areas: Areas and months within which a particular species or population selectively feeds. These may either be found consistently in space and time, or may be associated with ephemeral features that are less predictable but can be delineated and are generally located within a larger identifiable area.
Migratory Corridors: Areas and months within which a substantial portion of a species or population is known to migrate; the corridor is typically delimited on one or both sides by land or ice.
Small and Resident Population: Areas and months within which small and
resident populations occupying a limited geographic extent exist.
The delineation of BIAs does not have direct or immediate regulatory consequences. Rather, the BIA
assessment is intended to provide the best available science to help inform analyses and planning for applicants, and to support regulatory and management decisions under existing authorities, and to support the reduction of anthropogenic impacts on cetaceans and to achieve conservation and protection goals. In addition, the BIAs and associated information may be used to identify information gaps and prioritize future research and modeling efforts to better understand cetaceans, their habitat, and ecosystems. Table 4
provides a list of BIAs found within NEFSC fisheries research areas.

TABLE 4BIOLOGICALLY IMPORTANT AREAS WITHIN NEFSC RESEARCH AREAS
Size km2

BIA name
Species
BIA type
Time of year
Southwestern Gulf of Maine and Georges Bank.
Eastern Atlantic
East of Montauk Point
Great South Channel and Georges Bank Shelf.
Cape Cod Bay and MA Bay
Southern Gulf of Maine
Jeffreys Ledge
Gulf of Maine/Stellwagon Bank/Great South Channel.
Gulf of Maine
Central Gulf of MainParker Ridge and Cashes Ledge.
Gulf of Maine
Gulf of Maine
Northern Gulf of Maine

Minke whale

Feeding

MarchNov

54,341

NARW
Fin whale
NARW

Migration
Feeding
Feeding

North: MarchApril; South: NovDec
MarchOct
AprilJune

269,448
2,933
12,247

NARW
Fin whale
NARW
Humpback whale

Feeding Feeding Feeding Feeding

FebApril
Year-round
JuneJuly; OctDec
MarchDec

3,149
18,015
702
47,701

NARW
Minke whale

Reproduction
Feeding

NovJan
MarchNov

8,214
2,256

Harbor porpoise
Sei whale
Fin whale

Small and resident Feeding
Feeding

JulySept
MayNov
JuneOct

12,211
56,609
6,146

Marine Mammal Hearing Hearing is the most important sensory modality for marine mammals underwater, and exposure to anthropogenic sound can have deleterious effects. To appropriately assess the potential effects of exposure to sound, it is necessary to understand the frequency ranges marine mammals are able to hear. Current data indicate that not all marine mammal species
have equal hearing capabilities e.g., Richardson et al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008.
To reflect this, Southall et al. 2007
recommended that marine mammals be divided into functional hearing groups based on directly measured or estimated hearing ranges on the basis of available behavioral response data, audiograms derived using auditory evoked potential techniques, anatomical modeling, and other data. Generalized hearing ranges
were chosen based on the approximately 65 dB threshold from the normalized composite audiograms, with the exception for lower limits for lowfrequency cetaceans where the lower bound was deemed to be biologically implausible and the lower bound from Southall et al. 2007 retained. Marine mammal hearing groups and their associated hearing ranges are provided in Table 5.

TABLE 5MARINE MAMMAL HEARING GROUPS
NMFS, 2018
Generalized hearing range

Hearing group Low-frequency LF cetaceans baleen whales
Mid-frequency MF cetaceans dolphins, toothed whales, beaked whales, bottlenose whales
High-frequency HF cetaceans true porpoises, Kogia, river dolphins, cephalorhynchid, Lagenorhynchus cruciger & L.
australis.
Phocid pinnipeds PW underwater true seals

VerDate Sep<11>2014

17:49 Jun 03, 2021

Jkt 253001

PO 00000

Frm 00018

Fmt 4701

Sfmt 4702

E:FRFM04JNP2.SGM

04JNP2

7 Hz to 35 kHz.
150 Hz to 160 kHz.
275 Hz to 160 kHz.
50 Hz to 86 kHz.