Static acoustic monitoring (SAM) is one major technology for observing small cetacean species. Automatic click loggers deployed for long time periods (>2 months) with a single hydrophone are a standard solution. Acoustic properties, like detection thresholds of these instruments, are essential for interpretation of results, but have nevertheless received little attention. A methodology for calibrating tonal click detectors in small tanks consisting of the determination of the horizontal directivity pattern and detection thresholds including a transfer function is presented. Two approaches were tested to determine detection thresholds by (a) determining the 50% detection threshold and (b) fitting a linear regression model to the recorded relative amplitudes. The tests were carried out on C-PODs (Cetacean PODs, tonal click detectors), the most commonly used instrument for SAM in Europe. Directivity and threshold were tested between 60 and 150 kHz. Directivity showed a maximum variation of 8.5 dB in the horizontal plane. Sensitivity is highest between 80 and 130 kHz and linear (±3 dB) in this frequency range for most of the instruments tested. C-PODs have a detection threshold (calculated with the linear model) of 114.5 ± 1.2 (standard deviation) dB re 1 μPa peak–peak at 130 kHz.

1.
Akamatsu
,
T.
,
Nakazawa
,
I.
,
Tsuchiyama
,
T.
, and
Kimura
,
N.
(
2008
). “
Evidence of nighttime movement of finless porpoises through Kanmon Strait monitored using a stationary acoustic recording device
,”
Fish. Sci.
74
,
970
975
.
2.
Akamatsu
,
T.
,
Okumura
,
T.
,
Novarini
,
N.
, and
Yan
,
H. Y.
(
2002
). “
Empirical refinements applicable to the recording of fish sounds in small tanks
,”
J. Acoust. Soc. Am.
112
(
6
),
3073
3082
.
3.
ANSI (
2012
). S1.20:2012 “American National Standard Procedures for Calibration of Underwater Electroacoustic Transducers” (American National Standards Institute, Washington DC).
4.
Au
,
W. W. L.
, and
Hastings
,
M. C.
(
2008
). “
Echolocation in marine mammals
,” in
Principles of Marine Bioacoustics
, edited by
W. W. L.
Au
and
M. C.
Hastings
(
Springer
,
New York
), pp.
501
564
.
5.
Bates
,
D.
, and
Maechler
,
M.
(
2010
). “Lme4: Linear mixed-effects models using S4 classes,” R package version 0.999375-33. http://CRAN.R-project.org/package=lme4 (Last viewed 3 August 2012).
6.
Brandt
,
M.
,
Diederichs
,
A.
,
Betke
,
K.
, and
Nehls
,
G.
(
2011
). “
Responses of harbour porpoises to pile driving at the Horns Rev II offshore wind farm in the Danish North Sea
,”
Mar. Ecol. Prog. Ser.
421
,
205
216
.
7.
Carlström
,
J.
,
Berggren
,
P.
, and
Tregenza
,
N. J. C.
(
2009
). “
Spatial and temporal impact of pingers on porpoises
,”
Can. J. Fish. Aquat. Sci.
66
,
72
82
.
8.
Carstensen
,
J.
,
Henriksen
,
O. D.
, and
Teilmann
,
J.
(
2006
). “
Impacts of offshore wind farm construction on harbour porpoises: Acoustic monitoring of echolocating activity using porpoise detectors (T-PODs)
,”
Mar. Ecol. Prog. Ser.
321
,
295
308
.
32.
Dähne
,
M.
,
Gilles
,
A.
,
Lucke
,
K.
,
Peschko
,
V.
,
Adler
,
S.
,
Krügel
,
K.
,
Sundermeyer
,
J.
, and
Siebert
,
U.
(
2013
). “
Effects of pile-driving on harbour porpoises (Phocoena phocoena) at the first offshore wind farm in Germany
,”
Environ. Res. Lett.
8
,
025002
.
9.
Dähne
,
M.
,
Verfuß
,
U. K.
,
Diederichs
,
A.
,
Meding
,
A.
, and
Benke
,
H.
(
2006
). “
T-Pod test tank calibration and field calibration
,” in,
Proceeding of the Workshop on Static Acoustic Monitoring of Cetaceans (20th Conference of the European Cetacean Society Gdynia, Poland; 2–7 April 2006)
, edited by
R.
Leeney
and
N.
Tregenza
, ECS Spec. Publ. (ECS), Vol. 46, pp.
33
35
. Available at http://www.seaturtle.org/mtrg/personnel/SAM_report_ECS_2006.pdf.
10.
Foote
,
A. D.
,
Thomsen
,
P. F.
,
Sveegaard
,
S.
,
Wahlberg
,
M.
,
Kielgast
,
J.
,
Kyhn
,
L. A.
,
Salling
,
A. B.
,
Galatius
,
A.
,
Orlando
,
L.
, and
Gilbert
,
M. T. P.
(
2012
). “
Investigating the potential use of Environmental DNA (eDNA) for genetic monitoring of marine mammals
,”
PloS One
7
,
e41781
.
33.
Gallus
,
A.
,
Dähne
,
M.
,
Verfuß
,
U. K.
,
Bräger
,
S.
,
Adler
,
S.
,
Siebert
,
U.
, and
Benke
,
H.
(
2012
). “
Use of static passive acoustic monitoring to assess the status of the ‘Critically Endangered’ Baltic harbour porpoise in German waters
,”
Endangered Species Research
18
,
265
278
.
11.
Hardy
,
T.
,
Williams
,
R.
,
Caslake
,
R.
, and
Tregenza
,
N.
(
2012
). “
An investigation of acoustic deterrent devices to reduce cetacean bycatch in an inshore set net fishery
,”
J. Cetacean Res. Manage
12
,
85
90
.
12.
IEC 60565 (
2007
). “
Underwater acoustics – Hydrophones – Calibration in the frequency range 0.01 hz to 1 MHz
,” International Electrotechnical Commission, Geneva, Switzerland.
13.
IEC 61094-1/2/3/4/5/6 “
Measurement microphones, Series of microphone and calibration standards
,” International Electrotechnical Commission, Geneva, Switzerland.
14.
Koschinski
,
S.
,
Culik
,
B. M.
,
Trippel
,
E.
, and
Ginzkey
,
L.
(
2006
). “
Behavioral reactions of freeranging harbor porpoises Phocoena phocoena encountering standard nylon and BaSO4 mesh gillnets and warning sound
,”
Mar. Ecol. Prog. Ser.
313
,
285
294
.
15.
Kyhn
,
L. A.
,
Tougaard
,
J.
,
Teilmann
,
J.
,
Wahlberg
,
M.
,
Joergensen
,
P. B.
, and
Bech
,
N. I.
(
2008
). “
Harbour porpoise (Phocoena phocoena) static acoustic monitoring: Laboratory detection thresholds of T-PODs are reflected in field sensitivity
,”
J. Mar. Biol. Assoc. UK
88
(
6
),
1085
1091
.
16.
Kyhn
,
L. A.
,
Tougaard
,
J.
,
Thomas
,
L.
,
Duve
,
L. R.
,
Stenback
,
J.
,
Amundin
,
M.
,
Desportes
,
G.
, and
Teilmann
,
J.
(
2012
). “
From echolocation clicks to animal density-Acoustic sampling of harbor porpoises with static dataloggers
,”
J. Acoust. Soc. Am.
131
,
550
560
.
17.
Levin
,
P.
(
1973
). “
Calibration of hydrophones
,”
B&K Tech. Rev.
1
,
3
17
.
18.
Marques
,
T. A.
,
Thomas
,
L.
,
Ward
,
J.
,
DiMarzio
,
N.
, and
Tyack
,
P. L.
(
2009
). “
Estimating cetacean population density using fixed passive acoustic sensors: an example with Blainville's beaked whales
,”
J. Acoust. Soc. Am.
125
,
1982
1994
.
19.
Mellinger
,
D.
,
Stafford
,
K.
,
Moore
,
S.
,
Dziak
,
R.
, and
Matsumoto
,
H.
(
2007
). “
An overview of fixed passive acoustic observation methods for cetaceans
,”
Oceanography
20
,
36
45
.
20.
Philpott
,
E.
,
Englund
,
A.
,
Ingram
,
S.
, and
Rogan
,
E.
(
2007
). “
Using T-PODs to investigate the echolocation of coastal bottlenose dolphins
,”
J. Mar. Biol. Assoc. U.K.
87
,
11
17
.
21.
R Development Core Team
(
2011
).
R: A Language and Environment for Statistical Computing
(
R Foundation for Statistical Computing
,
Vienna, Austria
).
22.
Sasaki-Yamamoto
,
Y.
,
Akamatsu
,
T.
,
Ura
,
T.
,
Sugimatsu
,
H.
,
Kojima
,
J.
,
Bahl
,
R.
,
Behera
,
S.
, and
Kohshima
,
S.
(
2012
). “
Diel changes in the movement patterns of Ganges River dolphins monitored using stationed stereo acoustic data loggers
,”
Marine Mammal Science
, doi:.
23.
Tougaard
,
J.
,
Poulsen
,
L. R.
,
Amundin
,
M.
,
Larsen
,
F.
,
Rye Hansen
,
J.
, and
Teilmann
,
J.
(
2006
). “
Detection function of T-PODs and estimation of porpoise densities
,” in
Proceeding of the Workshop on Static Acoustic Monitoring of Cetaceans (20th Conference of the European Cetacean Society Gdynia, Poland; 2–7 April 2006)
, edited by
R.
Leeney
and
N.
Tregenza
, ECS Spec. Publ. Ser. (ECS), Vol. 46, pp.
7
14
.
24.
Tougaard
,
J.
,
Carstensen
,
J.
,
Teilmann
,
J.
,
Skov
,
H.
, and
Rasmussen
,
P.
(
2009
). “
Pile driving zone of responsiveness extends beyond 20 km for harbor porpoises (Phocoena phocoena (L))
,”
J. Acoust. Soc. Am.
126
,
11
14
.
25.
Verfuß
,
U.
,
Adler
,
S.
,
Brandecker
,
A.
,
Dähne
,
M.
,
Diederichs
,
A.
,
Gallus
,
A.
,
Herrmann
,
A.
,
Krügel.
K.
,
Lucke
,
K.
,
Teilmann
,
J.
,
Tougaard
,
J.
,
Tregenza
,
N.
,
Siebert
,
U.
, and
Benke
,
H.
(
2010
). “
Applications and analysis methods for the deployment of T-PODs in environmental impact studies for wind farms: Comparability and development of standard methods
,” Final Report (FKZ 0327587) (Deutsches Meeresmuseum, Stralsund, Germany), pp.
112
.
26.
Verfuß
,
U. K.
,
Dähne
,
M.
,
Diederichs
,
A.
, and
Benke
,
H.
(
2008a
). “
Application and analytical methods for T-POD deployment in environmental impact studies for wind farms: Comparability and development of standard methods
,” edited by P. G. H. Evans, ECS Spec. Publ. Ser. (ECS),Vol.
49
, pp.
27
31
.
35.
Verfuß
,
U. K.
,
Dähne
,
M.
,
Gallus
,
A.
,
Jabbusch
,
M.
, and
Benke
,
H.
(
2013
). “
Determining the detection thresholds for harbor porpoise clicks of autonomous data loggers, the Timing Porpoise Detectors
,”
J. Acoust. Soc. Am.
134
(
3
),
2462
2468
.
27.
Verfuß
,
U. K.
,
Honnef
,
C. G.
,
Meding
,
A.
,
Dähne
,
M.
,
Adler
,
S.
,
Kilian
,
A.
, and
Benke
,
H.
(
2008b
). “
The history of the German Baltic Sea harbour porpoise acoustic monitoring at the German Oceanographic Museum
,” in
Marine Mammals and Seabirds in Front of Offshore Wind Energy
, edited by
K.
Wollny-Goerke
and
K.
Eskildsen
(
Teubner Verlag/GWV Fachverlage GmbH
,
Wiesbaden, Germany
), pp.
41
56
.
28.
Verfuß
,
U. K.
,
Honnef
,
C. G.
,
Meding
,
A.
,
Dähne
,
M.
,
Mundry
,
R.
, and
Benke
,
H.
(
2007
). “
Geographical and seasonal variation of harbour porpoise (Phocoena phocoena) presence in the German Baltic Sea revealed by passive acoustic monitoring
,”
J. Mar. Biol. Assoc. U.K.
87
,
165
176
.
29.
Villadsgaard
,
A.
,
Wahlberg
,
M.
, and
Tougaard
,
J.
(
2007
). “
Echolocation signals of wild harbour porpoises, Phocoena phocoena
,”
J. Exp. Biol.
210
,
56
64
.
30.
Wenger
,
D.
, and
Koschinski
,
S.
(
2012
). “
Harbour porpoise (Phocoena phocoena Linnaeus, 1758) entering the Weser river after decades of absence
,”
Mar. Biol. Res.
8
,
737
745
.
31.
Zuur
,
A. F.
,
Ieno
,
E. N.
, and
Smith
,
G. M.
(
2007
).
Analysing Ecological Data
(
Springer
,
New York
), pp.
672
.
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