Target strength of Japanese Common squid(Todarodes pacifica) using Acoustic backscattering theoretical model

2021 ◽  
Vol 14 (1) ◽  
pp. 63-68
Author(s):  
HeeSeung YANG ◽  
MinSoo KIM ◽  
WooSeok OH ◽  
KyoungHoon LEE
Keyword(s):  
Theoretical Model ◽  
Target Strength ◽  
Acoustic Backscattering ◽  
Common Squid ◽  
Japanese Common Squid

scholarly journals The influence of tilt angle on the acoustic target strength of the Japanese common squid (Todarodes pacificus)

2005 ◽  
Vol 62 (4) ◽  
pp. 779-789 ◽  
Author(s):  
Donhyug Kang ◽  
Tohru Mukai ◽  
Kohji Iida ◽  
Doojin Hwang ◽  
Jung-Goo Myoung
Keyword(s):  
Tilt Angle ◽  
Empirical Relationship ◽  
Ex Situ ◽  
Target Strength ◽  
Todarodes Pacificus ◽  
Common Squid ◽  
Acoustic Target ◽  
The Mean ◽  
Highly Correlated ◽  
Japanese Common Squid

Abstract To measure the influence of changes in tilt angle on the acoustic target strength (TS) of the Japanese common squid (Todarodes pacificus), we conducted a series of experiments to estimate TS in relation to tilt angle and swimming angle. Swimming angle was measured in a seawater tank using two infrared, underwater cameras under dark conditions. Ex situ measurements of TS in relation to tilt angle on live specimens using a fishhook and cage method were then conducted at 38 and 120 kHz; mantle length (ML) ranged from 21 to 27 cm (mean 24.75 cm). For the more precise TS measurement with tilt angle, another set of ex situ TS measurements relative to tilt angle was made at 38 and 120 kHz on tethered, anesthetized specimens in seawater. The mean swimming angle was −17.7° (±12.7° s.d.). The mean TS varied from −48.6 to −44.6 dB and was relatively higher at 120 kHz than at 38 kHz, in the order of 0.7 and 2.5 dB. The empirical relationship between TS (dB) and ML (cm) is given by TS = 20 log10(ML) − 75.4 (r = 0.81) at 38 kHz or TS = 20 log10(ML) − 73.5 (r = 0.64) at 120 kHz. Based on the tethered method for the anesthetized squid, the mean standardized TS values (b20) were found to be highly correlated with the tilt angle, and the resultant fitted equations for b20 were expressed as: b20 = −73.3 + 0.48 × Θ + 0.0122 × Θ2 + 0.00016 × Θ3 for 38 kHz and b20 = −72.6 + 0.53 × Θ + 0.0134 × Θ2 + 0.00014 × Θ3 for 120 kHz, where Θ is the negative tilt angle in degrees. The mean TS based on the measurements using live squid was higher than that of tethered measurements, i.e., 2.6 dB at 38 kHz and 4.0 dB at 120 kHz. The higher mean TS in the ex situ measurements for the live squid can be explained by the influence of the low tilt angle on the overall TS data. The results can be used to understand the influence of tilt angle on the TS of Todarodes pacificus and thus improve the accuracy of biomass estimates.

scholarly journals Acoustic Target Strength of Live Japanese Common Squid(Todarodes pacifica) for Applying Biomass Estimation

2004 ◽  
Vol 37 (4) ◽  
pp. 345-353 ◽  
Author(s):  
Donhyug KANG ◽  
Doojin HWANG ◽  
Tohru MUKAI ◽  
KohjI IIDA ◽  
Kyounghoon LEE
Keyword(s):  
Target Strength ◽  
Biomass Estimation ◽  
Common Squid ◽  
Acoustic Target ◽  
Japanese Common Squid

Analisis Akustik Target Strength Penyu Hijau (Chelonia Mydas) Melalui Pengukuran Secara Terkontrol Pada Frekuensi 200 kHz

2021 ◽  
Vol 3 (2) ◽  
pp. 94-108
Author(s):  
Teddy Julyansyah ◽  
Deddy Bakhtiar ◽  
Ari Anggoro
Keyword(s):  
Green Turtle ◽  
Population Decline ◽  
Chelonia Mydas ◽  
Total Body Length ◽  
Acoustic Method ◽  
Target Strength ◽  
Acoustic Backscattering ◽  
Total Length ◽  
In Captivity ◽  
Total Body

ABSTRACT Turtles are reptiles that live in the sea and are able to migrate over long distances along the Indian Ocean, Pacific Ocean and Southeast Asia. Currently the number of turtle populations in nature has greatly decreased. This population decline is caused by natural factors and human activities that endanger the population directly or indirectly. At this time the tagging set technique (ID tag code) is a method that is often used to detect the presence of turtles by attaching tags to female turtles who are landing to lay eggs on the beach or while in captivity or the discovery of the mother turtle by fishermen. One other method that can be used to detect the presence of turtles is to use the acoustic method. The purpose of this study was to analyze the characteristics of the acoustic backscattering energy of the green turtle (Chelonia mydes) and to analyze the relationship between target strength and total body length of the green turtle (Chelonia mydas). This research was conducted in the Tapak Paderi waters pond, Bengkulu City, in August-October 2020. The average target strength (TS) value for green turtles was -48.07 dB. Based on the regression equation, the value of determination (R2) obtained is 0.78. Where this value shows that the total length of the green turtle has an effect of 78% on the average target strength (TS) value, while for 22% it is caused by other factors such as body shape, environmental factors and other factors. Based on the ANOVA test, it can be concluded that there is a relationship between the total length and the value of the target strength (TS) on the green turtle or the value of the total length has an influence on the value of the target strength (TS) on the green turtle.  

Acoustic backscattering by Hawaiian lutjanid snappers. I. Target strength and swimbladder characteristics

2003 ◽  
Vol 114 (5) ◽  
pp. 2757 ◽  
Author(s):  
Kelly J. Benoit-Bird ◽  
Whitlow W. L. Au ◽  
Christopher D. Kelley
Keyword(s):  
Target Strength ◽  
Acoustic Backscattering

ACID- AND HEAT-STABLE TRYPSIN INHIBITORY PEPTIDE FROM THE VISCERA OF JAPANESE COMMON SQUID (TODARODES PACIFICUS)

2010 ◽  
Author(s):  
HIDEKI KISHIMURA ◽  
YUJIRO NAGAI ◽  
KANA FUKUMORITA ◽  
KOHSUKE ADACHI ◽  
SATORU CHIBA ◽  
...  
Keyword(s):  
Inhibitory Peptide ◽  
Heat Stable ◽  
Todarodes Pacificus ◽  
Common Squid ◽  
Japanese Common Squid

scholarly journals Spatio-Temporal Variability of the Habitat Suitability Index for the Todarodes Pacificus (Japanese Common Squid) around South Korea

2019 ◽  
Vol 11 (23) ◽  
pp. 2720 ◽  
Author(s):  
Lee ◽  
Son ◽  
Lee ◽  
Kang ◽  
Lee
Keyword(s):  
South Korea ◽  
Habitat Suitability ◽  
Sea Surface ◽  
Fishing Ground ◽  
Habitat Suitability Index ◽  
Fishery Resources ◽  
Todarodes Pacificus ◽  
Suitability Index ◽  
Common Squid ◽  
Japanese Common Squid

The climate-induced changes in marine fishery resources in South Korea have been a big concern over the last decades. The climate regime shift has led to not only a change in the dominant fishery resources, but also a decline in fishery landings in several species. The habitat suitability index (HSI) has been widely used to detect and forecast fishing ground formation. In this study, the catch data of the Todarodes pacificus (Japanese Common Squid) and satellite-derived environmental parameters were used to estimate the HSI for the T. pacificus around South Korea. More than 80% of the total catch was found in regions with a sea surface temperature (SST) of 14.91–27.26 ℃, sea surface height anomaly (SSHA) of 0.05–0.20 m, chlorophyll-a of 0.32–1.35 mg m-3, and primary production of 480.41–850.18 mg C m-2 d-1. Based on these results, the HSI model for T. pacificus was derived. A strong positive relationship (R2 = 0.9260) was found between the HSI and the fishery landings. The climatological monthly mean HSI from 2002 to 2016 showed several hotspots, coinciding with the spawning and feeding grounds of T. pacificus. This outcome implies that our estimated HSI can yield a reliable prediction of the fishing ground for T. pacificus around South Korea. Furthermore, the approach with the simple HSI model used in this study can be applied elsewhere, and will help us to understand the spatial and temporal distribution of fishery resources.

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