Using the simple slab-cylinder acoustic model for fish, developed by Clay and Horne [J. Acoust. Soc. Am. 96, 1661–1668 (1994)], the target strengths of three of New Zealand’s deep-water fish species, namely orange roughy, black oreos, and smooth oreos, have been derived. The target strengths derived for the model fish have been found to be in reasonable agreement with currently accepted target strength values. These three model fish were used in a study to test the species discrimination of a chirp sonar system. Chirps of center frequencies 40, 80, and 160 kHz and bandwidth of 10, 20, and 40 kHz have been used to acoustically illuminate the three fish species listed above and the matched, filtered responses to the chirps determined. The effect of the response of transducer or system bandwidth has also been investigated. It has been found that the bandwidth of the chirp is much more important for resolving detail in a fish target than the chirp center frequency. A bandwidth of at least 20 kHz, and preferably 40 kHz, produces matched filtered responses for black and smooth oreos and orange roughy which are quite clearly species specific. Results suggest that with orange roughy it may be possible to size and even sex the targets acoustically.

1.
Barr, R. (2000). “Black and smooth oreo target strength developments,” slides presented to Deep Water Fishery Assessment Working Group, Greta Point, 20 April 2000, Document number 00/41, held by Ministry of Fisheries, Wellington.
2.
Chu
,
D.
, and
Stanton
,
T. K.
(
1998
). “
Applications of pulse compression techniques to broadband acoustic scattering by live individual zooplankton
,”
J. Acoust. Soc. Am.
104
,
39
55
.
3.
Clark, M. (1995). “Experience with management of orange roughy (Hoplostethus Atlanticus) in New Zealand waters, and the effects of commercial fishing on stock over the period 1980–1993,” in Deepwater Fisheries of the North Atlantic Oceanic Slope, edited by A. G. Hopper (Kluwer Academic, Dordrecht).
4.
Clark
,
M.
, and
Tracy
,
D. M.
(
1994
). “
Changes in a population of orange roughy, Hoplostethus Atlanticus, with commercial exploitation on the Challenger Plateau, New Zealand
,”
Fish. Bull.
92
,
236
253
.
5.
Clay
,
S. C.
(
1992
). “
Composite ray-mode approximations for backscattered sound from gas-filled cylinders and swimbladders
,”
J. Acoust. Soc. Am.
92
,
2173
2180
.
6.
Clay
,
S. C.
, and
Horne
,
J. K.
(
1994
). “
Acoustic models of fish: The Atlantic cod (Gadus morhua)
,”
J. Acoust. Soc. Am.
96
,
1661
1668
.
7.
Coombs, R. F., Barr, R., and Hart, A. C. (2000). “Target strength of black and smooth oreos,” unpublished draft paper, part of Doonan et al. (2000) listed below, held by Ministry of Fisheries, Wellington.
8.
Cordue, P. L. (1996). “On the feasibility of using acoustic techniques to estimate orange roughy and oreo biomass on underwater hills,” New Zealand Fisheries Assessment Research Document 96/22.
9.
CRC (1973). Handbook of Chemistry and Physics (CRC Press, Boca Raton).
10.
Do
,
M. A.
, and
Coombs
,
R. F.
(
1989
). “
Acoustic measurements of the population of orange roughy (Hoplostethus Atlanticus) on the north Chatham Rise, New Zealand
,”
New Zealand J. Mar. Freshwater Res.
23
,
225
237
.
11.
Doonan, I. J., Coombs, R. F., McMillan, P. J., and Dunn, A. (1998). “Estimate of the absolute abundance of black and smooth oreo in OEO 3A and 4 on the Chatham Rise,” Final research report for the New Zealand Ministry of Fisheries Research Project No. OEO9701, NIWA.
12.
Doonan, I. J., Hart, A., McMillan, P. J., and Coombs, R. F. (2000). “Oreo abundance estimates from the October 1998 survey of the south Chatham Rise, OEO 4,” Final research report for the New Zealand Ministry of Fisheries Research Project No. OEO9801, NIWA.
13.
Doonan, I. J. (2000). Private communication.
14.
Elliot
,
N. G.
, and
Kloser
,
R. J.
(
1993
). “
Use of acoustics to assess a small aggregation of orange roughy, Hoplostethus Atlanticus (Collet), off eastern coast of Tasmania
,”
Aust. J. Mar. Freshwater Res.
44
,
407
413
.
15.
Foote
,
K. G.
(
1980
). “
Importance of the swimbladder in acoustic scattering by fish: A comparison of gadoid and mackerel target strengths
,”
J. Acoust. Soc. Am.
67
,
2084
2089
.
16.
Hart, A. (2000). Private communication.
17.
Jech
,
J. M.
, and
Horne
,
J. K.
(
1998
). “
Sensitivity of acoustic scattering models to fish morphometry
,”
J. Acoust. Soc. Am.
103
,
2958
(A).
18.
Kloser
,
R. J.
,
Koslow
,
J. A.
, and
Williams
,
A.
(
1996
). “
Acoustic assessment of the biomass of a spawning aggregation of orange roughy (Hoplostethus Atlanticus, Collet) off Southeastern Australia, 1990–93
,”
Mar. Freshwater Res.
47
,
1015
1024
.
19.
Kloser, R. J., Ryan, T. E., Williams, A., and Soule, M. (2000). “Development and implementation of an acoustic survey of orange roughy in the Chatham Rise Spawning box from the commercial factory trawler, Amaltal Explorer,” Report 597.64, CSIRO Marine Research, Hobart, Tasmania.
20.
Koslow
,
J. A.
,
Kloser
,
R.
, and
Stanley
,
C. A.
(
1995
). “
Avoidance of a camera system by a deepwater fish, orange roughy (Hoplostethus Atlanticus)
,”
Deep-Sea Res., Part I
42
,
233
244
.
21.
Koslow, J. A., and Kloser, R. J. (1999). “Development of acoustic methods to survey orange roughy in the Eastern and Southern Zones,” Report FRDC 95/031, CSIRO Division of Marine Research, Hobart, Tasmania.
22.
LeFeuvre
,
P.
,
Rose
,
G. A.
,
Gosine
,
R.
,
Hale
,
R.
,
Pearson
,
W.
, and
Kahn
,
R.
(
2000
). “
Acoustic species identification in the Northwest Atlantic using digital image processing
,”
Fisheries Res.
47
,
137
147
.
23.
Mackenzie
,
K. V.
(
1981
). “
Nine-term equation for sound speed in the oceans
,”
J. Acoust. Soc. Am.
70
,
808
812
.
24.
McClatchie
,
S.
,
Aslop
,
J.
,
Ye
,
Z.
, and
Coombs
,
R. F.
(
1996
). “
Consequence of swimbladder model choice and fish orientation to target strength of three New Zealand fish species
,”
ICES J. Mar. Sci.
53
,
847
862
.
25.
McClatchie
,
S.
,
Macauly
,
G.
,
Coombs
,
R. F.
,
Grimes
,
P.
, and
Hart
,
A.
(
1999
). “
Target strength of an oily deep-water fish, orange roughy (Hoplostethus Atlanticus). I. Experiments
,”
J. Acoust. Soc. Am.
106
,
1
12
.
26.
McClatchie
,
S.
, and
Ye
,
Z.
(
2000
). “
Target strength of an oily deep-water fish, orange roughy (Hoplostethus Atlanticus). II. Modeling
,”
J. Acoust. Soc. Am.
107
,
1280
1285
.
27.
McClatchie, S., (2000).
28.
Medwin, H., and Clay, S. C. (1998). Fundamentals of Acoustical Oceanography (Academic, London).
29.
Paul, L. J. (1986). New Zealand Fishes: An Identification Guide (Reed Methuen, Auckland, New Zealand).
30.
Phleger
,
C. F.
, and
Grigor
,
M. R.
(
1990
). “
Role of wax esters in determining buoyancy in Hoplostethus Atlanticus (Beryciormes: Trachichthyidae)
,”
Mar. Biol. (Berlin)
105
,
229
233
.
31.
Rose
,
G. A.
, and
Leggett
,
W. C.
(
1988
). “
Hydroacoustic signal classification of fish schools by species
,”
Can. J. Fish. Aquat. Sci.
45
,
597
604
.
32.
Scalabrin
,
C.
,
Diner
,
N.
,
Weill
,
A.
,
Hillion
,
A.
, and
Mouchot
,
M.
(
1996
). “
Narrowband acoustic identification of monospecific fish shoals
,”
ICES J. Mar. Sci.
53
,
181
188
.
33.
Shibata, K. (1969). “Study on details of ultrasonic reflection from individual fish,” thesis submitted for the degree of Doctor of Fisheries at the Hokkaido University.
34.
Stanton
,
T. K.
,
Clay
,
C. S.
, and
Chu
,
D.
(
1993
). “
Ray representation of sound scattering by weakly scattering deformed fluid cylinders: Simple physics and applications to zooplankton
,”
J. Acoust. Soc. Am.
94
,
3454
3462
.
35.
UNESCO (1981). “Background papers and supporting data on the International Equation of State of Seawater 1980,” UNESCO Technical papers in marine science.
36.
Ye
,
Zhen
(
1997
). “
Low-frequency acoustic scattering by gas-filled prolate spheroids in liquids
,”
J. Acoust. Soc. Am.
101
,
1945
1952
.
This content is only available via PDF.
You do not currently have access to this content.