The relationship between the temporal-spatial distribution of fishing ground of yellowfin tuna (Thunnus albacares) and themocline characteristics in the tropic Indian Ocean

2012 ◽  
Vol 32 (3) ◽  
pp. 671-679 ◽  
Author(s):  
杨胜龙 YANG Shenglong ◽  
张禹 ZHANG Yu ◽  
张衡 ZHANG Heng ◽  
王栋 WANG Dong ◽  
马军杰 Ma Junjie ◽  
...  
2013 ◽  
Vol 111 (3) ◽  
pp. 252-264 ◽  
Author(s):  
Iker Zudaire ◽  
Hilario Murua ◽  
Maitane Grande ◽  
Nathalie Bodin

2017 ◽  
Vol 14 (3) ◽  
pp. 313 ◽  
Author(s):  
Budi Nugraha ◽  
Enjah Rahmat

Tulisan ini menyajikan tentang status perikanan huhate di Bitung meliputi deskripsi unit penangkapan, daerah penangkapan, komposisi hasil tangkapan, catch per unit of effort, dan ukuran ikan pertama kali tertangkap. Data dikumpulkan selama tahun 2004 sampai dengan 2005. Hasil penelitian menunjukkan bahwa huhate yang terdapat di Bitung dioperasikan dengan kapal penangkapan yang terbuat dari kayu berukuran 50 sampai dengan 80 GT. Daerah penangkapan di sekitar lokasi rumpon di Laut Sulawesi dan Laut Maluku. Hasil tangkapan yang diperoleh terdiri atas cakalang (Katsuwonus pelamis), madidihang (Thunnus albacares), baby tuna (Thunnus spp.), dan tongkol (Auxis spp.) serta hasil tangkapan sampingan yaitu lemadang (Coryphaena hippurus) dan sunglir (Elagatis bipinnulatus). Hasil analisis catch per unit of effort diperoleh bahwa nilai catch per unit of effort baby tuna (Thunnus spp.) mengalami kenaikan pada bulan Agustus 2004, dan cakalang (Katsuwonus pelamis) mengalami kenaikan pada bulan September 2004. Hasil analisis terhadap ukuran pertama kali cakalang (Katsuwonus pelamis) tertangkap oleh huhate 49,3 FLcm. Ukuran ini lebih panjang dibandingkan ukuran pertama kali cakalang (Katsuwonus pelamis) matang gonad. Sedangkan hasil analisis terhadap ukuran pertama kali madidihang (Thunnus albacares) tertangkap oleh huhate 51,6 FLcm. Ukuran ini lebih pendek dibandingkan ukuran pertama kali madidihang (Thunnus albacares) matang gonad. This paper presents the status of pole and line fishery in Bitung of North Sulawesi, consisting of description of fishing gear, fishing ground, catch composition, catch per unit of effort, and length at first capture. Data were collected during the period of 2004 until 2005. Results show that the pole and line in Bitung operated by wooden vessels of 50 until 80 GT. The fishing grounds were the waters around FADs location in Sulawesi Sea and Maluku Sea. Catch composition consists of skipjack tuna (Katsuwonus pelamis), yellow fin tuna (Thunnus albacares), baby tuna (Thunnus spp.), and frigate tuna (Auxis spp.), while the bycatch consisted of dolphinfish (Coryphaena hippurus) and rainbow runner (Elagatis bipinnulatus). Catch per unit of effort analysis shows that catch per unit of effort value of baby tuna (Thunnus spp.) increased on August 2004, whereas catch per unit of effort value of skipjack tuna (Katsuwonus pelamis) increased on September 2004. The length at first capture of skipjack tuna (Katsuwonus pelamis) was 49,3 FLcm. The catch size was bigger than the length at first maturity for skipjack tuna (Katsuwonus pelamis). The length at first capture of yellowfin tuna (Thunnus albacares) was 51,6 FLcm. This catch size was smaller than the length at first maturity for yellowfin tuna (Thunnus albacares).


2012 ◽  
Vol 4 (1) ◽  
Author(s):  
Retno Andamari ◽  
Jhon Haryanto Hutapea ◽  
Budi Iskandar Prisantoso

<p>Tuna is one of the important fishery commodities in Indonesia, including tuna caught by longliners in Indian Ocean. The most popular of tuna is yellowfin tuna (Thunnus albacares). Currently, the production of tuna based on the capture fisheries, therefore, in order to preserve its sustainability, the understanding of the biological and reproduction aspect is required. Research on the biological reproduction of this species was conducted at Gondol Research Institute for Mariculture. Samples of female gonad were collected from Indian Ocean tuna longliners during April to July 2009 from the processing companies within Benoa Port. Result of the histological analysis on 128 female gonads showed that majority of gonads were at the early development level and the only 16 gonads have reached at the mature level. The analysis of the oocyte development showed the asynchronous, indicating that yellowfin tuna is a multiple spawner.</p><p>Keywords: yellowfin tuna, gonad, asynchronous</p>


2020 ◽  
Vol 153 ◽  
pp. 01006
Author(s):  
Jalil ◽  
Achmar Mallawa ◽  
Faisal Amir ◽  
Safruddin

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.


2018 ◽  
Vol 75 (6) ◽  
pp. 2145-2152 ◽  
Author(s):  
Rachel B Mullins ◽  
Niall J McKeown ◽  
Warwick H H Sauer ◽  
Paul W Shaw

Abstract The South African (SAF) yellowfin tuna (Thunnus albacares) fishery represents a potential example of misalignment between management units and biological processes. The SAF fishery spans an operational stock with a boundary at 20°E, either side of which fish are considered part of Atlantic or Indian Ocean regional stocks. However, the actual recruitment of fish from Atlantic and Indian Ocean spawning populations into SAF waters is unknown. To address this knowledge gap, genomic analysis (11 101 SNPs) was performed on samples from Atlantic and Indian Ocean spawning sites, including SAF sites spanning the current stock boundary. Outlier loci conferred high discriminatory power to assignment tests and revealed that all SAF fish were assigned to the Indian Ocean population and that no Atlantic Ocean fish appeared in the SAF samples. Additionally, several Indian Ocean migrants were detected at the Atlantic spawning site demonstrating asymmetric dispersal and the occurrence of a mixed-stock fishery in Atlantic waters. This study highlights both the spatial inaccuracy of current stock designations and a misunderstanding of interactions between the underlying biological units, which must be addressed in light of local and global declines of the species. Specifically, the entire SAF fishery must be managed as part of the Indian Ocean stock.


2013 ◽  
Vol 33 (19) ◽  
pp. 6345-6353
Author(s):  
杨胜龙 YANG Shenglong ◽  
马军杰 MA Junjie ◽  
张禹 ZHANG Yu ◽  
化成君 HUA Chengjun ◽  
戴阳 DAI Yang

2015 ◽  
Vol 21 (2) ◽  
pp. 75 ◽  
Author(s):  
Khairul Amri ◽  
Ali Suman ◽  
Hari Eko Irianto ◽  
Wudianto Wudianto

The effects of Indian Ocean Dipole Mode and El Niño–Southern Oscillation events on catches of YellowfinTuna (<em>Thunnus albacares</em>) in the Eastern Indian Ocean (EIO) off Java were evaluated through the use of remotely sensed environmental data (sea surface temperature/SST and chlorophyll-a concentration/SSC) and Yellowfin Tuna catch data. Analyses were conducted for the period of 2003–2012, which included the strong positive dipole mode event in association with weak El-Nino 2006.Yellowfin Tuna catch data were taken from Palabuhanratu landing place and remotely sensed environmental data were taken from MODIS-Aqua sensor.The result showed that regional climate anomaly Indian Ocean Dipole Mode influenced Yellowfin Tuna catch and its composition. The catches per unit effort (CPUE) of Thunnus alabacares in the strong positive dipole mode event in 2006 and weak El-Nino events in 2011 and 2012 was higher. The increase patern of CPUE followed the upwelling process, started from May-June achieved the peak between September-October.Very high increase in CPUE when strong positive dipole mode event (2006) and a weak El-Nino events (2011 and 2012) had a relation with the increase in the distribution of chlorophyll-a indicating an increase in the abundance of phytoplankton (primary productivity) due to upwelling. In contrast, yellowfin tuna CPUE is very low at the La-Nina event (2005), though as the dominant catch when compared to others.


2019 ◽  
Vol 11 (3) ◽  
pp. 161
Author(s):  
Maya Agustina ◽  
Bram Setyadji ◽  
Prawira Atmaja Rintar Pandapotan Tampubolon

Tuna sirip kuning (Thunnus albacares) merupakan hasil tangkapan terbanyak dibandingkan dengan jenis tuna lainnya di Indonesia. Ketersediaan stok tuna sirip kuning di Samudra Hindia, pada saat ini, diperkirakan dalam keadaan lebih tangkap. Oleh karena itu, pengelolaan secara tepat dan bertanggungjawab penting dilakukan untuk melindungi spesies tuna, salah satu caranya dengan mengkaji alat tangkap yang digunakan. Tulisan ini bertujuan untuk mengungkapkan produktivitas dan hasil tangkapan armada tonda, serta struktur ukuran dan hubungan panjang bobot ikan tuna sirip kuning yang di daratkan di selatan Jawa. Komposisi tangkapan tertinggi dari armada tonda diseluruh pendaratan ikan tuna di selatan Jawa terdiri atas tuna sirip kuning dan cakalang. Analisis CPUE menunjukkan hasil yang fluktuatif di setiap lokasi pendaratan tuna sirip kuning di Selatan Jawa. Tuna sirip kuning yang tertangkap di selatan Jawa dengan armada tonda sebagian besar adalah ikan yang belum layak tangkap karena berukuran kurang dari 100 cmFL. Struktur ukuran panjang tuna sirip kuning yang tertangkap semakin ke Timur semakin panjang ukurannya. Pola pertumbuhan tuna sirip kuning yang tertangkap di Binuangeun memiliki pola isometrik, PPN Palabuhanratu bersifat allometrik Positif, PPP Sadeng, P2SKP Pacitan, PPN Prigi dan P2SKP Sendang Biru bersifat allometrik negatif. Yellowfin tuna (Thunnus albacares) is the largest catch compared to other tuna species in Indonesia. The availability of yellowfin tuna stock in the Indian Ocean, at present, is estimated to be in overfished condition. Therefore, proper and responsible management is important to protect the species. One of the ways is by studying the used fishing gear. This paper aims at determining vessel’s productivity, as well as composition, size structure and length-weight relationship of yellowfin tuna catches from troll line fleet in the Indian Ocean part of south Java. The highest catch of tuna in all of the troll line landing places was yellowfin tuna, following by skipjack tuna. CPUE analysis showed fluctuating results at each landing site. Yellowfin tuna sizes caught by troll line fleet were mostly less than 100 cmFL and categorized as should not be properly caught. Geographically, getting to the east the average size of the catches tend to be larger. The growth pattern of yellowfin tuna catches landed in Binuangeun was isometric; Palabuhanratu was positive allometric; while those landed in Sadeng, Pacitan, Prigi and Sendang Biru were negative allometric.


2019 ◽  
Vol 70 (12) ◽  
pp. 1708 ◽  
Author(s):  
Iraide Artetxe-Arrate ◽  
Igaratza Fraile ◽  
David A. Crook ◽  
Iker Zudaire ◽  
Haritz Arrizabalaga ◽  
...  

A better understanding of the stock structure of yellowfin tuna (Thunnus albacares) in the Indian Ocean is needed to ensure the sustainable management of the fishery. In this study, carbon and oxygen stable isotopes (δ13C and δ18O) and trace elements (138Ba, 55Mn, 25Mg and 88Sr) were measured in otoliths of young-of-the-year (YOY) and age-1 yellowfin tuna collected from the Mozambique Channel and north-west Indian Ocean regions. Elemental profiles showed variation in Ba, Mg and Mn in YOY otolith composition, but only Mn profiles differed between regions. Differences in YOY near-core chemistry were used for natal-origin investigation. Ba, Mg and Mn were sufficiently different to discriminate individuals from the two regions, in contrast with carbon and oxygen stable isotopes. A linear discriminant analysis resulted in 80% correct classification of yellowfin tuna to their natal origin. Classification success increased to 91% using a random forest algorithm. Finally, a unique larval source was detected among age-1 yellowfin tuna. The signal of these fish resembled that of YOY from a north-west Indian Ocean origin, highlighting the importance of local production. The present study supports the use of otolith chemistry as a promising approach to analyse yellowfin stock structure in the Indian Ocean.


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