QUANTIFICATION OF TUNA FISH TARGET STRENGTH USING QUANTITATIVE ECHO SOUNDER

2009 ◽  
Vol 1 (1) ◽  
Author(s):  
Henry M. Manik
Keyword(s):  
Wave Reflection ◽  
Fork Length ◽  
Research Programme ◽  
Yellowfin Tuna ◽  
Target Strength ◽  
Bigeye Tuna ◽  
Tuna Fish ◽  
Thunnus Obesus ◽  
The Relationship ◽  
Echo Sounder

A preliminary research programme was carried out in order to study the acoustic wave reflection or target strength (TS) of tuna fish using a quantitative echo sounder (QES). The relationships between TS to fork length (FL) and swimbladder volume, for bigeye tuna (Thunnus obesus) and yellowfin tuna (T. albacares) are investigated. The TS of bigeye tuna was about 3 dB higher than yellowfin tuna when comparing species at the same size. The result can be correlated to the swimbladder volume differencebetween species. The relationship between TS and swimbladder volume was quantified for both species.Keywords: tuna fish, target strength, quantitative echo sounder

scholarly journals QUANTIFICATION OF TUNA FISH TARGET STRENGTH USING QUANTITATIVE ECHO SOUNDER

2009 ◽  
Vol 1 (1) ◽  
Author(s):  
Henry M. Manik
Keyword(s):  
Fork Length ◽  
Research Programme ◽  
Yellowfin Tuna ◽  
Target Strength ◽  
Bigeye Tuna ◽  
Tuna Fish ◽  
Thunnus Obesus ◽  
The Relationship ◽  
Volume Difference ◽  
Echo Sounder

<p>A preliminary research programme was carried out in order to study the acoustic wave reflection or target strength (TS) of tuna fish using a quantitative echo sounder (QES). The relationships between TS to fork length (FL) and swimbladder volume, for bigeye tuna (Thunnus obesus) and yellowfin tuna (T. albacares) are investigated. The TS of bigeye tuna was about 3 dB higher than yellowfin tuna when comparing species at the same size. The result can be correlated to the swimbladder volume difference<br />between species. The relationship between TS and swimbladder volume was quantified for both species.</p><p>Keywords: tuna fish, target strength, quantitative echo sounder</p>

scholarly journals PARASITES AS POTENTIAL STOCK MARKERS FOR TUNA IN INDONESIAN WATERS

2017 ◽  
Vol 23 (1) ◽  
pp. 23 ◽  
Author(s):  
Pratiwi Lestari ◽  
R.J.G Lester ◽  
Craig Proctor
Keyword(s):  
Fisheries Management ◽  
Solomon Islands ◽  
Fork Length ◽  
Yellowfin Tuna ◽  
Fish Parasites ◽  
Bigeye Tuna ◽  
Tuna Fish ◽  
Migration Patterns ◽  
Thunnus Obesus ◽  
And Migration

Tuna fish are highly migratory species. Clarifying their stock structures and migration patterns is important for tuna fisheries management. The purpose of this research was to examine the parasites of bigeye tuna (Thunnus obesus) and yellowfin tuna (Thunnus albacares) to determine which parasites may be potential stock markers for assessment of tuna migration patterns. Bigeye tuna and yellowfin tuna were collected (measured between 28-48 cm fork length) from 9 sites across Indonesia and from 2 ‘outlier sites’ (The Maldives and Solomon Islands). Organs including gills (filaments and branchial arches), stomach wall, liver, pyloric caeca, and intestines were examined. Seven types of didymozoids were distinguished including 3 Didymosulcus spp., 4 Kollikeria spp. and one acanthocephalan (Bolbosoma sp.). The results suggest these fish parasites are potentially useful markers for assessment of tuna migration pattern, contributing information needed for fisheries management in Indonesia.

scholarly journals Age and growth estimation of bigeye tuna, Thunnus obesus (Teleostei: Scombridae) in the southwestern Atlantic

2012 ◽  
Vol 10 (1) ◽  
pp. 148-158 ◽  
Author(s):  
Paulo Duarte-Neto ◽  
Fábio M. Higa ◽  
Rosangela P. Lessa
Keyword(s):  
Fork Length ◽  
Age And Growth ◽  
Data Uncertainty ◽  
Bigeye Tuna ◽  
Western Atlantic ◽  
Thunnus Obesus ◽  
Marginal Increment ◽  
Back Calculation ◽  
Growth Estimation ◽  
Averaged Model

The purpose of the current study was to supply the first information on age and growth for Thunnus obesus caught in the equatorial south-western Atlantic using dorsal spines, an approach that has been successfully employed for ageing tuna species. The study was conducted using a multi-model inference based on information theory for back-calculated and observed length-at-age data. Uncertainty associated with the parameter estimation was verified and results were compared to other accounts on the species, considering both the statistical and methodological contexts. Samples were collected in Natal city (Rio Grande do Norte State, Brazil) from February 1999 to January 2000, of tuna vessels and from surveys, aimed at providing information on the Brazilian Exclusive Economic Zone (EEZ) in the area around São Pedro and São Paulo Archipelago. Validation using marginal increment indicated that one ring is deposited per year. Mean length-at-age ranged of 54.3 to 177.5 cm (fork length) for ages 1 to 9 years. Von Bertalanffy, Richards, and Gompertz models were considered suitable for the bigeye tuna. Hence, the model-averaged asymptotic length ¯L∞ was estimated. The averaged model generated in the present study by back-calculation was considered appropriate for describing the growth of T. obesus.

scholarly journals KOMPOSISI JENIS DAN DISTRIBUSI UKURAN IKANPELAGIS BESAR HASILTANGKAPANPANCINGULURDI SENDANGBIRU, JAWATIMUR

2017 ◽  
Vol 3 (6) ◽  
pp. 377
Author(s):  
Ria Faizah ◽  
Aisayah Aisayah
Keyword(s):  
Species Composition ◽  
Size Distribution ◽  
Landing Site ◽  
Pelagic Fish ◽  
Yellowfin Tuna ◽  
Thunnus Albacares ◽  
Bigeye Tuna ◽  
Katsuwonus Pelamis ◽  
Individual Weight ◽  
Thunnus Obesus

Sendang Biru merupakan salah satu tempat pendaratan ikan pelagis besar di Jawa Timur. Penelitian tentang komposisi jenis dan ukuran ikan pelagis besar hasil tangkapan pancing ulur yang didaratkan di PPI Pondok Dadap, Sendang Biru, Jawa Timur, dilakukan pada bulanApril dan Oktober 2010. Hasil penelitian menunjukkan hasil tangkapan pancing ulur didominasi oleh jenis tuna (Thunnus albacares dan Thunnus obesus) 45%, cakalang (Katsuwonus pelamis) sebesar 38 %, dan lainnya (marlin, lemadang, lauro) sebesar 1,7 %. Ikan tuna yang didaratkan terdiri dari jenis yellowfin tuna (Thunnus albacares) dan bigeye tuna (T. obesus) dengan ukuran panjang cagakmasing –masing berkisar antara 40 - 170 cmFL dan 40 - 140 cmFL. Berat individumasing-masing berkisar antara 0.1 - 71 kg dan 0.5 - 43 kg. Sendang Biru is one of big pelagic’s landing site in East Java. Tuna on this research are caught by handline that landing in PPI Pondok Dadap, Sendang Biru, East Java. Research on the species composition and size distribution of big pelagic fish caught by handline were carried out during April and October 2010 at Sendang Biru, East Java. The result showed that Thunnus sp. are the most landed (45%) followed by Katsuwonus pelamis (38 %) and others (Xiphias gladius, Coriphaena sp., Elagatis bipinnulatus) of 1.7 %. The dominant fork lengthof Thunnus albacares and Thunnus obesus ranged from about 40 - 170 cm and 40 – 140 cm. Individual weight ranged between 0.1 - 71 kg and 0.5 - 43 kg respectivelly.

scholarly journals Size composition and length-weight relationships of the Yellowfin Tuna (Thunnus albacares) in Bone Bay

2020 ◽  
Vol 153 ◽  
pp. 01006
Author(s):  
Jalil ◽  
Achmar Mallawa ◽  
Faisal Amir ◽  
Safruddin
Keyword(s):  
Growth Pattern ◽  
Condition Factor ◽  
Average Length ◽  
Fork Length ◽  
Size Composition ◽  
Yellowfin Tuna ◽  
Thunnus Albacares ◽  
Weight Measurement ◽  
Weight Relationship ◽  
The Relationship

The size composition, length-weight relationship, and condition factor of Thunnus albacares were examined in Bone Bay. Sampling was conducted at two stations, i.e., Station I at Cimpu in Luwu Regency and Station II at Lonrae in Bone Regency between July 2018 and June 2019. 10246 and 2651 yellowfin tunas were captured in Station I and Station II, respectively. Measurement of the fork length ranged between 20 cm and 192 cm with an average length of 81,257 ± 33,456 cm in Station I, and between 26 to 162 cm with an average length of 95,479 cm in Station II. The weight measurement ranged between 0,35 and 99,21 kg with an average of 14,539 kg in Station I, and between 0,46 and 97,35 kg with an average of 26,978 kg in Station II. Calculation of the relationship was based on the formula W= 5,5−5FL2,7454 (R2 = 0,963) in Station I, and W=4,1−5FL2,9103 (R2 = 0,761) in Station II. The values of condition factor at Station I and Station II were 2,1395 and 3,4374, respectively. It is quite evident that the growth pattern of the yellowfin tunas at Bone Bay was negatively allometric, indicating that the length increased faster than the weight.

scholarly journals In situ target strength of bigeye tuna (Thunnus obesus) associated with fish aggregating devices

2019 ◽  
Author(s):  
G Boyra ◽  
G Moreno ◽  
B Orue ◽  
B Sobradillo ◽  
I Sancristobal
Keyword(s):  
Frequency Response ◽  
Target Strength ◽  
Species Discrimination ◽  
Bigeye Tuna ◽  
Central Pacific ◽  
Commercial Fish ◽  
Thunnus Obesus ◽  
Tropical Tuna ◽  
Fish Aggregating Devices

Abstract Bigeye tuna (Thunnus obesus) is an important commercial fish species, which aggregates around fish aggregating devices (FADs) together with other tropical tuna species. Acoustics is the main technology used by fishers and scientists for the location and quantification of tunas at FADs. However, currently it is not possible to reliably discriminate between the different tropical tuna species that are found together at FADs using acoustic methods, which hampers the development of selective fishing needed to preserve some of the tropical tuna species for which overfishing is occurring. One of the prerequisites for species discrimination is to know the target strength (TS) of each species at different frequencies. This paper measures in situ TS values and explores the frequency response of bigeye tuna at FADs in the central Pacific Ocean using three different acoustic frequencies. For the range of body length caught (40–100 cm), the obtained b20 values were −65, −66, and −72 dB for 38, 120, and 200 kHz, respectively. The decreasing frequency response pattern obtained for this swimbladder bearing species contrasts with the opposite pattern previously observed for skipjack tuna (bladder-less), the most abundant tuna species found at FADs, hence allowing the potential for discrimination between the two species.

scholarly journals In situ target strength estimates of optically verified southern blue whiting (Micromesistius australis)

2012 ◽  
Vol 70 (2) ◽  
pp. 431-439 ◽  
Author(s):  
Richard L. O'Driscoll ◽  
Johannes Oeffner ◽  
Adam J. Dunford
Keyword(s):  
New Zealand ◽  
Confidence Interval ◽  
Fork Length ◽  
Target Strength ◽  
Blue Whiting ◽  
Acoustic Target ◽  
The Mean ◽  
The Relationship ◽  
Immature Fish

Abstract O'Driscoll, R. L., Oeffner, J., and Dunford, A. J. 2013. In situ target strength estimates of optically verified southern blue whiting (Micromesistius australis) – ICES Journal of Marine Science, 70: 431–439. Estimates of the acoustic target strength (TS) of southern blue whiting (Micromesistius australis) at 38 kHz were obtained using an autonomous acoustic–optical system (AOS) mounted on a demersal trawl. Data were collected from aggregations of spawning adult [mean fork length (FL) 34.4 cm] and immature (mean FL 24.6 cm) southern blue whiting south of New Zealand. Mean TS was estimated from 162 tracks containing 695 echoes from targets identified from video as southern blue whiting. The mean TS was –37.9 dB with a 95% confidence interval (CI) of –39.7 to –36.6 dB for 21 immature fish and –34.6 dB (95% CI –35.4 to –34.0 dB) for 141 adults. A logarithmic fit through the mean TS values produced a TS–fork length (FL) relationship from optically verified targets of TS = 22.06 log10FL – 68.54. This new relationship gives TS values within 1 dB of those estimated using the relationship recently adopted by ICES for blue whiting (Micromesistius poutassou) of TS = 20 log10TL – 65.2 (where TL is total length) obtained from in situ measurements, but higher values than those estimated from the previous relationship for southern blue whiting of TS = 38 log10FL – 97, which was based on swimbladder modelling.

Movements and oceanographic associations of bigeye tuna (Thunnus obesus) in the Northwest Atlantic

2014 ◽  
Vol 71 (10) ◽  
pp. 1529-1543 ◽  
Author(s):  
Chi Hin Lam ◽  
Benjamin Galuardi ◽  
Molly E. Lutcavage
Keyword(s):  
Fork Length ◽  
Geographic Location ◽  
South Atlantic Bight ◽  
Sargasso Sea ◽  
Bigeye Tuna ◽  
Equatorial Atlantic ◽  
Northwest Atlantic ◽  
Swimming Depth ◽  
Thunnus Obesus ◽  
Additive Mixed Models

To address the lack of fisheries-independent information for Atlantic bigeye tuna (Thunnus obesus), we released 21 adults (131 ± 12 cm curved fork length) between 2008 and 2010 in the Sargasso Sea and Northwest Atlantic. Data from nine tags (range: 1–292 days; mean: 89 days) revealed (i) pronounced north–south movements in pelagic waters between areas including Georges Bank, Mid- and South Atlantic Bight, Caribbean Sea, and Brazilian shelf, (ii) a lack of east–west exchange, and (iii) a high-use area in the Hatteras Plain, centered southwest of Bermuda. Bigeye tuna occupied water masses of 2.7–28.2 °C and depths of 0–1280 m, with deeper depths in the daytime (daily mean ± standard deviation: 196 ± 92 m) than at nighttime (45 ± 29 m). Even though bigeye tuna are assumed to forage on the deep scattered layer during the day, generalized additive mixed models did not identify the deep scattered layer as an important predictor of daytime swimming depth. Model results highlight the importance of geographic location in influencing habitat utilization, and thus suggest the need for fisheries-independent monitoring in high-catch areas, such as the central and equatorial Atlantic.

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