Evaluating harvest control rules for bigeye tuna (Thunnus obesus) and yellowfin tuna (Thunnus albacares) fisheries in the Indian Ocean

2013 ◽  
Vol 137 ◽  
pp. 1-8 ◽  
Author(s):  
Yuying Zhang ◽  
Yong Chen ◽  
Jiangfeng Zhu ◽  
Siquan Tian ◽  
Xinjun Chen
Keyword(s):  
Indian Ocean ◽  
Yellowfin Tuna ◽  
Thunnus Albacares ◽  
Bigeye Tuna ◽  
Control Rules ◽  
Thunnus Obesus ◽  
The Indian Ocean ◽  
Harvest Control Rules

scholarly journals CHANGES IN FISHING PATTERN FROM SURFACE TO DEEP LONGLINE FISHING BY THE INDONESIAN VESSELS OPERATING IN THE INDIAN OCEAN

2017 ◽  
Vol 17 (2) ◽  
pp. 87
Author(s):  
Lilis Sadiyah ◽  
Natalie Dowling ◽  
Budi Iskandar Prisantoso
Keyword(s):  
Time Series ◽  
Indian Ocean ◽  
Yellowfin Tuna ◽  
Supplementary Information ◽  
Thunnus Albacares ◽  
Spatial Distributions ◽  
Bigeye Tuna ◽  
Valuable Source ◽  
The Indian Ocean

(P.T. Perikanan Samodra Besar) data are a valuable source, since they are the longest time series of catch and effort data available from the fishery. This paper aimed to interpret the spatial and temporal catch and effort trends to the extent possible and to reconcile apparent changes in targeting practices against the actual catch. Catch and effort data collected by P.T. Perikanan Samodra Besar from its Benoa-based longliners during 1978-1995 were summed to obtain annual catch, effort, and catch per unit of effort trends. To generate spatial distributions of catch and effort, catch and effort data were aggregated by 5-degree squares. The data showed that P.T. Perikanan Samodra Besar vessels commenced deep longlining in 1983, i.e. 56% of the total sets in 1983 using 10 or more hooks between floats. Prior to that, P.T. Perikanan Samodra Besar vessels used 6 hooks between floats,which resulted in a larger amount of yellowfin tuna (Thunnus albacares) as well as overall tuna catch. However, bigeye tuna (Thunnus obsesus) catch per unit of effort only increased from 1992. The increase in big eye tuna catch per unit of effort coincided with a reduced fishing range and concentration within an area where P.T. Perikanan Samodra Besar had not previously experienced high big eye tuna catches, as opposed to focusing their effort on areas where they had historically caught big eye tuna. In the absence of supplementary information, and assuming that the switch to deep longlining in 1983 was done to target big eye tuna, the analysis suggests that the outcome of P.T. Perikanan Samodra Besar fishing activities between 1983 and 1991 were inconsistent with their objectives.

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 Genomic analysis reveals multiple mismatches between biological and management units in yellowfin tuna (Thunnus albacares)

2018 ◽  
Vol 75 (6) ◽  
pp. 2145-2152 ◽  
Author(s):  
Rachel B Mullins ◽  
Niall J McKeown ◽  
Warwick H H Sauer ◽  
Paul W Shaw
Keyword(s):  
Indian Ocean ◽  
Genomic Analysis ◽  
Yellowfin Tuna ◽  
Thunnus Albacares ◽  
Management Units ◽  
Spawning Site ◽  
Asymmetric Dispersal ◽  
Outlier Loci ◽  
The Indian Ocean ◽  
Mixed Stock

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.

scholarly journals PERIKANAN TUNA SIRIP KUNING (Thunnus albacares Bonnaterre, 1788) PADA ARMADA TONDA DI SAMUDERA HINDIA SELATAN JAWA

2019 ◽  
Vol 11 (3) ◽  
pp. 161
Author(s):  
Maya Agustina ◽  
Bram Setyadji ◽  
Prawira Atmaja Rintar Pandapotan Tampubolon
Keyword(s):  
Indian Ocean ◽  
Size Structure ◽  
Landing Site ◽  
Yellowfin Tuna ◽  
Fishing Gear ◽  
Thunnus Albacares ◽  
Skipjack Tuna ◽  
The Indian Ocean ◽  
Average Size ◽  
Relationship Of

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.

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