scholarly journals Target strength measurement of Caroun croaker (Johnius sp.) and acoustic fish density estimation in Musi Estuary, South Sumatra

2021 ◽  
Vol 944 (1) ◽  
pp. 012008
Author(s):  
F Supriyadi ◽  
I Jaya ◽  
S Pujiyati ◽  
T Hestirianoto ◽  
Z Fahmi
Keyword(s):  
Survey Design ◽  
Economic Value ◽  
Acoustic Pulse ◽  
Target Strength ◽  
Estuarine Fish ◽  
Fish Length ◽  
Acoustic Survey ◽  
Strength Measurement ◽  
Fish Stocks ◽  
Length Relationship

Abstract Caroun Croaker ( Johnius sp.) is one of the dominant estuarine fish that has a reasonably high economic value. The target strength (TS) value measurement is essential in calculating the density of fish stocks using the hydroacoustic method. Target strength measurement of Caroun Croaker (Johnius sp.) and an acoustic survey in Musi Estuary Waters of South Sumatra Province was conducted in December 2019. The result of TS measurement will be used to estimate the acoustic density along the survey area. The TS measurement used the standard tethered method, tying placing the fish in a fixed cage, transmitting the acoustic pulse, and analyzing its return using the scientific acoustic instrument Biosonic DT-X 200 KHz. The fisheries acoustic survey was carried out in the area around the Musi estuary with a predetermined survey design. The results of the measurements have obtained the TS-length relationship, as TS= 20 LOG L-78.79 with determinant value of R2= 0.67 for fish length ranges from 18.1-23.3 cm, and an acoustic survey showed that the estimated stock density value was 286 kg/ha for the total surveyed area of 1.612 ha.

Evaluation of target strength–fish length equation choices for estimating estuarine fish biomass

Hydrobiologia ◽  
2008 ◽  
Vol 610 (1) ◽  
pp. 113-123 ◽  
Author(s):  
Kevin M. Boswell ◽  
Michael D. Kaller ◽  
James H. Cowan ◽  
Charles A. Wilson
Keyword(s):  
Target Strength ◽  
Estuarine Fish ◽  
Fish Length ◽  
Fish Biomass

scholarly journals In situ target strength of the Baltic Sea herring and sprat

2004 ◽  
Vol 61 (3) ◽  
pp. 378-382 ◽  
Author(s):  
Tomas Didrikas ◽  
Sture Hansson
Keyword(s):  
Baltic Sea ◽  
Clupea Harengus ◽  
Target Strength ◽  
Fish Length ◽  
The North ◽  
Length Relationship ◽  
Stock Biomass ◽  
Acoustic Target ◽  
The North Sea ◽  
The Baltic

Abstract Using single- and split-beam hydroacoustic equipment (70 and 38 kHz), and gillnet and trawl catches, we derived the relationship TS = 25.5 log10 L − 73.6 (r2=0.95) between acoustic target strength (TS) and fish length (L, cm) for Baltic Sea herring (Clupea harengus membras L.) and sprat (Sprattus sprattus balticus (Schneider)). Fixing the slope to 20, which is a standard practice in hydroacoustics, gave TS = 20 log10 L − 67.8 (r2=0.91). Normally, the fisheries agencies around the Baltic use a TS–length relationship that is based mainly on data from the North Sea and the intercept-value in this equation is 3.4 dB lower than that reported in this paper. This difference corresponds to an approximately twofold difference in assessed stock biomass.

scholarly journals Boarfish (Capros aper) target strength modelled from magnetic resonance imaging (MRI) scans of its swimbladder

2013 ◽  
Vol 70 (7) ◽  
pp. 1451-1459 ◽  
Author(s):  
Sascha M. M. Fässler ◽  
Ciaran O'Donnell ◽  
J. M. Jech
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Three Dimensional ◽  
Target Strength ◽  
Fish Length ◽  
Commercial Fishing ◽  
Resonance Imaging ◽  
Length Relationship ◽  
Mri Scans ◽  
Magnetic Resonance Imaging Mri

Abstract Fässler, S. M. M., O'Donnell, C., and Jech, J.M. 2013. Boarfish (Capros aper) target strength modelled from magnetic resonance imaging (MRI) scans of its swimbladder. – ICES Journal of Marine Science, 70: . Boarfish (Capros aper) abundance has increased dramatically in the Northeast Atlantic from the early 1970s after successive years of good recruitment attributed to an increase in sea surface temperature. Due to increased commercial fishing over recent years, an acoustic boarfish survey funded by the Killybegs Fishermen's Organisation was initiated by the Marine Institute to establish a baseline for the future management of this stock. In the absence of any species-specific boarfish target strength (TS), acoustic backscatter was estimated by a Kirchhoff-ray mode model using reconstructed three-dimensional swimbladder shapes which were computed from magnetic resonance imaging scans of whole fish. The model predicted TS as a function of size, fish tilt angle, and operating frequency. Standardized directivity patterns revealed the increasing importance of changes in the inclination of the dorsal swimbladder surface at higher frequencies (120 and 200 kHz) and a less directive response at lower frequencies (18 and 38 kHz). The model predicted a TS-to-total fish length relationship of TS = 20 log10(L) − 66.2. The intercept is ∼1 dB higher than in the general physoclist relationship, potentially reflecting the bulky nature of the boarfish swimbladder with its relatively large circumference.

The acoustic target strength of herring (Clupea harengus L.) in the northern Baltic Sea

2005 ◽  
Vol 62 (4) ◽  
pp. 803-808 ◽  
Author(s):  
Heikki Peltonen ◽  
Helge Balk
Keyword(s):  
Baltic Sea ◽  
Clupea Harengus ◽  
Target Strength ◽  
Fish Length ◽  
The Baltic Sea ◽  
Length Relationship ◽  
Acoustic Target ◽  
The Baltic ◽  
Catch Composition ◽  
Bothnian Sea

Abstract The hydro-acoustic target strength (TS) of herring (Clupea harengus L.) was estimated from the catch composition of 19 pelagic-trawl hauls and from simultaneous recordings with a split-beam, 38 kHz echosounder. The data were collected in September 2000 during a Bothnian Sea survey in the northern Baltic Sea. The dependence of TS (in dB) on fish length (L, cm) was modelled with the equation TS = a log10 L + b. The fitted model was TS = 16.8 log10 L − 60.0. With a predefined slope of 20 the TS vs. log-fish length relationship was TS = 20 log10 L − 63.9. The analyses suggested that TS was higher in the Bothnian Sea than is assumed in most studies in the Baltic Sea. Applying the revised TS–length dependence considerably enhanced the agreement between the biomass estimates from hydroacoustics and those from a catche-at-age analysis (VPA).

Fecundity of the American Plaice, Hippoglossoides platessoides (Fabr.) from Grand Bank and Newfoundland Areas

1964 ◽  
Vol 21 (3) ◽  
pp. 597-612 ◽  
Author(s):  
T. K. Pitt
Keyword(s):  
Egg Production ◽  
Fish Length ◽  
Northern Slope ◽  
Southern Slope ◽  
Ovary Weight ◽  
Length Relationship ◽  
Relationship Of ◽  
Hippoglossoides Platessoides

Fecundity estimates were made on a total of 140 mature American plaice from the southern and northern slopes of the Grand Bank and from St. Mary's Bay. Log–log relationships were established between fecundity and fish length, gutted and gilled weight, age, and ovary weight. No differences were found to exist between the fecundity–length relationship of plaice from the three areas, but there is a suggestion that within areas there may be annual differences in egg production. At comparable ages plaice from the southern slope of the Grand Bank are larger in size and produce more eggs than those from the northern slope and St. Mary's Bay.

Assessment of fish stocks and economic value in accordance with fishway renovation: Case study of Samcheokoshipcheon0010 Weir

2020 ◽  
Vol 38 (1) ◽  
pp. 30-39
Author(s):  
Woon-Ki Moon ◽  
Dae-Yeul Bae ◽  
Do-Hyun Kim ◽  
Hyun-Beom Shin ◽  
Jung Bin Suh ◽  
...  
Keyword(s):  
Economic Value ◽  
Fish Stocks

scholarly journals Target strength measurement of free-swimming jack mackerel using an indoor large experimental tank

2019 ◽  
Vol 85 (1) ◽  
pp. 2-16
Author(s):  
YOHEI KAWAUCHI ◽  
KENJI MINAMI ◽  
HOKUTO SHIRAKAWA ◽  
KAZUSHI MIYASHITA ◽  
YUKA IWAHARA ◽  
...  
Keyword(s):  
Target Strength ◽  
Jack Mackerel ◽  
Experimental Tank ◽  
Strength Measurement ◽  
Free Swimming

scholarly journals Decoupling of otolith and somatic growth during anadromous migration in a northern salmonid

2019 ◽  
Vol 76 (11) ◽  
pp. 1940-1953 ◽  
Author(s):  
Christie M. Morrison ◽  
Mélodie Kunegel-Lion ◽  
Colin P. Gallagher ◽  
Rick J. Wastle ◽  
Ellen V. Lea ◽  
...  
Keyword(s):  
Life History ◽  
Critical Time ◽  
Somatic Growth ◽  
Fish Growth ◽  
Calcium Deposition ◽  
Fish Length ◽  
Length Relationship ◽  
Anadromous Migration ◽  
Back Calculation ◽  
Size At Age

We assessed the fish length – otolith length relationship (FL–OL) in Dolly Varden (Salvelinus malma malma) to verify proportional growth. A decoupling was detected during first ocean migration where fish growth was occurring at a greater rate than otolith growth. Because of this decoupling, the application of traditional back-calculation models overestimated the size-at-age in premigratory char. We developed modified back-calculation equations from existing traditional models to account for this decoupling based on discontinuous piecewise regressions. The new biological intercept breakpoint method (BI–BP) provided the most accurate representation of fish size-at-age throughout all life history stages when compared with known size-at-capture values in fish. The decoupling indicates that factors other than somatic growth are important for otolith accretion. Physiological changes during smoltification likely alter calcium uptake and thereby affect calcium deposition rates on otoliths during this short but biologically critical time period of life history. It is probable that species exhibiting similar complex ontogenetic shifts in life history will likely exhibit decoupling to some extent in the FL–OL relationship.

scholarly journals Target Strength and swimbladder morphology of Mueller’s pearlside (Maurolicus muelleri)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
B. Sobradillo ◽  
G. Boyra ◽  
U. Martinez ◽  
P. Carrera ◽  
M. Peña ◽  
...  
Keyword(s):  
Relevant Information ◽  
Target Strength ◽  
Fish Length ◽  
Mesopelagic Fish ◽  
Bay Of Biscay ◽  
Numerical Abundance ◽  
Density Filter ◽  
Pressure Changes ◽  
First Time ◽  
Best Fit

AbstractIn the last few years, there has been increasing interest in the commercial exploitation of mesopelagic fish and a trawl-acoustic methodology has been recommended to make estimates of abundance of these resources. This study provides relevant information on the scattering properties of a key mesopelagic fish species in the Bay of Biscay, Mueller’s pearlside (Maurolicus muelleri), necessary to convert the acoustic density into numerical abundance. The target strength (TS) of pearlside was estimated for the first time at five frequencies commonly used in acoustic surveys. A high-density filter was applied to reduce the bias derived from overlapping echoes erroneously assigned to single targets. Its relationship with fish length (b20) was also determined (−65.9 ± 2, −69.2 ± 3, −69.2 ± 2, −69.5 ± 2.5 and −71.5 ± 2.5 dB at 18, 38, 70, 120 and 200 kHz, respectively). Biomass estimates of pearlside in the Bay of Biscay during the four years of study (2014–2017) are given using the 38 kHz frequency. Morphological measurements of the swimbladder were obtained from soft X-ray images and used in the backscattering simulation of a gas-filled ellipsoid. Pearlside is a physoclist species, which means that they can compensate the swimbadder volume against pressure changes. However, the best fit between the model and the experimental data showed that they lose that capacity during the trawling process, when the swimbladder volume is affected by Boyle’s law.

scholarly journals In situ target-strength measurement of young hairtail (Trichiurus haumela) in the Yellow Sea

2006 ◽  
Vol 63 (1) ◽  
pp. 46-51 ◽  
Author(s):  
Xianyong Zhao
Keyword(s):  
Confidence Interval ◽  
Yellow Sea ◽  
The Yellow Sea ◽  
Target Strength ◽  
Abundance Estimation ◽  
Strength Measurement ◽  
The Mean

Abstract The target strength of hairtail (Trichiurus haumela) in the Yellow Sea was measured in situ with a 38 kHz, split-beam echosounder on 2 January 2001. The fish measured were of the 2000 year class, its anal length ranged from 62 to 115 mm, with a mean of 89.8 mm. The mean target strength of these young hairtail was estimated to be −49.2 dB, with a 95% confidence interval of (−49.4, −49.0) dB. This provided a rare and useful reference for the acoustic-abundance estimation of hairtail.

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