Yoshinori MIYAMOTO, Tamami SAKAI, Masahiko FURUSAWA, Yasuhiko NAITO
(2004): Development of high-frequency micro echo sounder. Fisheries
Science; Volume 70, Issue 3, Page 381-388
Abstract:
The authors have developed a micro echo sounder operating at a frequency
as high as 1 MHz, which can be attached to aquatic animals in
combination with a depth and temperature sensor to obtain information on
the animal's prey as well as its behavior. The performance of the
sounder was evaluated in an experimental tank and its detection range
was estimated to confirm its effectiveness. The beam width is 5.9° and
the maximum detection distance is estimated as 34 m when the target
strength of an object animal is 50 dB.
Link:
<a
href="http://www.blackwell-synergy.com/links/doi/10.1111/j.1444-2906.2004.00817.x";
rel="nofollow">http://www.blackwell-synergy.com/links/doi/10.1111/j.1444-2906.2004.00817.x</a>
Seiji OHSHIMO (2004): Spatial distribution and biomass of pelagic fish
in the East China Sea in summer, based on acoustic surveys from 1997 to
2001. Fisheries Science; Volume 70, Issue 3, Page 389 ff
Abstract:
Annual acoustic surveys were conducted using a quantitative echo sounder
(frequency: 38 kHz) in the East China Sea from July to September of
1997-2001. Three groups of fish were identified from the echograms,
based on school shape and swimming depth characteristics: (i) anchovy
Engraulis japonicus and round herring Etrumeus teres; (ii) jack mackerel
Trachurus japonicus and chub mackerel Scomber japonicus; and (iii)
lantern fish Diaphus spp. and pearlside Maurolicus japonicus. The area
backscattering strength (Sa) of each group was divided by the total
weight of fish species caught in midwater trawls. Anchovy, round
herring, jack mackerel, lantern fish and pearlside were the most
abundant. The estimated biomass indices of anchovy and round herring
were positively correlated with the commercial landings of these
species, indicating the usefulness of acoustic surveys.
Link:
<a
href="http://www.blackwell-synergy.com/links/doi/10.1111/j.1444-2906.2004.00818.x";
rel="nofollow">http://www.blackwell-synergy.com/links/doi/10.1111/j.1444-2906.2004.00818.x</a>
Sincerly,
Sonja Amoser
Mag. Sonja Amoser
Institut of Zoology, University of Vienna
Althanstrasse 14, 1090 Vienna, Austria
Tel: +43-1-4277-54515
Mail: [EMAIL PROTECTED]
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