Automated and manual acoustic localizations of migrating bowhead whales were used to estimate source level and calling depth distributions of their frequency-modulated-modulated calls over seven years between 2008 and 2014. Whale positions were initially triangulated using directional autonomous seafloor acoustic recorders, deployed between 25 and 55 m water depth near Kaktovik, Alaska, during the fall westward migration. Calling depths were estimated by minimizing the “discrepancy” between source level estimates from at least three recorders detecting the same call. Applying a detailed waveguide propagation model to the data yielded broadband source levels of 161 ± 9 dB re 1 μPa2 s at 1 m (SEL) for calls received between 20 and 170 Hz. Applying a simpler 15 log10(R) power-law propagation model yielded SEL source levels of 158 ± 10 dB. The most probable calling depths lay between 22 and 30 m: optimal depths for long-range acoustic signal transmission in this particular environment.

1.
Abadi
,
S. H.
,
Thode
,
A. M.
,
Blackwell
,
S. B.
, and
Dowling
,
D. R.
(
2014
). “
Comparison of three methods of ranging bowhead whale calls in a shallow-water waveguide
,”
J. Acoust. Soc. Am.
136
,
130
144
.
2.
Blackwell
,
S. B.
,
Nations
,
C. S.
,
McDonald
,
T. L.
,
Greene
,
C. R.
, Jr.
,
Thode
,
A. M.
,
Guerra
,
M.
, and
Macrander
,
A. M.
(
2013
). “
Effects of airgun sounds on bowhead whale calling rates in the Alaskan Beaufort Sea
,”
Mar. Mammal Sci.
29
,
E342
E365
.
3.
Blackwell
,
S. B.
,
Nations
,
C. S.
,
McDonald
,
T. L.
,
Thode
,
A. M.
,
Mathias
,
D.
,
Kim
,
K. H.
,
Greene
,
C. R.
, Jr.
, and
Macrander
,
A. M.
(
2015
). “
Effects of airgun sounds on bowhead whale calling rates: Evidence for two behavioral thresholds
,”
PLoS One
10
(
6
),
e0125720
.
5.
Bonnel
,
J.
,
Thode
,
A. M.
, and
Blackwell
,
S. B.
(
2014
). “
Range estimation of bowhead whale (Balaena mysticetus) calls in the Arctic using time warping on a single hydrophone
,”
J. Acoust. Soc. Am.
136
,
145
155
.
6.
Clark
,
C. W.
, and
Johnson
,
J. H.
(
1984
). “
The sounds of the bowhead whale, Balaena mysticetus, during the spring migrations of 1979 and 1980
,”
Can. J. Zool.
62
,
1436
1441
.
7.
Cummings
,
W. C.
, and
Holliday
,
D. V.
(
1987
). “
Sounds and source levels from bowhead whales off Pt. Barrow, Alaska
,”
J. Acoust. Soc. Am.
82
,
814
821
.
8.
Delarue
,
J.
,
Mouy
,
X.
,
Chadwick
,
J.
,
Fischbach
,
A.
, and
Hannay
,
D.
(
2015
). “
Underwater source level measurements of vocalizing walruses in the Chukchi Sea and implications of detection range and communication space in natural and human-influenced soundscapes
,” in
21st Biennial Society for Marine Mammalogy Conference on the Biology of Marine Mammals
, San Francisco, CA.
9.
D'Spain
,
G. L.
,
Murray
,
J. J.
,
Hodgkiss
,
W. S.
,
Booth
,
N. O.
, and
Schey
,
P. W.
(
1999
). “
Mirages in shallow water matched field processing
,”
J. Acoust. Soc. Am.
105
,
3245
3265
.
10.
Gerstoft
,
P.
(
1997
). “
SAGA Users Guide 2.0, an inversion software package
,” SM-333 (SACLANT Undersea Research Centre, La Spezia, Italy).
11.
Greene
,
C. R.
,
McLennan
,
M. W.
,
Norman
,
R. G.
,
McDonald
,
T. L.
,
Jakubczak
,
R. S.
, and
Richardson
,
W. J.
(
2004
). “
Directional frequency and recording (DIFAR) sensors in seafloor recorders to locate calling bowhead whales during their fall migration
,”
J. Acoust. Soc. Am.
116
,
799
813
.
12.
Lenth
,
R. V.
(
1981
). “
Robust measures of location for directional data
,”
Technometrics
23
,
77
81
.
13.
Mouy
,
X.
,
Delarue
,
J.
,
Martin
,
B.
,
Hannay
,
D.
,
Jay
,
C.
, and
Fishbach
,
A.
(
2014
). “
Real-time acoustic monitoring and source level estimates of walruses in the northeastern Chukchi Sea using particle velocity sensors
,”
J. Acoust. Soc. Am.
135
,
2361
2362
.
14.
Porter
,
M. B.
(
1991
). “
The KRAKEN normal mode program
,” SM-245 (SACLANT Undersea Research Centre, La Spezia, Italy).
16.
Thode
,
A.
,
Kim
,
K. H.
,
Greene
,
C. R.
, Jr.
, and
Roth
,
E.
(
2010
). “
Long range transmission loss of broadband seismic pulses in the Arctic under ice-free conditions
,”
J. Acoust. Soc. Am.
128
,
EL181
EL187
.
15.
Thode
,
A. M.
,
Kim
,
K. H.
,
Blackwell
,
S. B.
,
Greene
,
C. R.
, Jr.
, and
Macrander
,
A. M.
(
2012
). “
Automated detection and localization of bowhead whale sounds in the presence of seismic airgun surveys
,”
J. Acoust. Soc. Am.
131
,
3726
3747
.
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