scholarly journals PERTUMBUHAN DAN MORTALITAS IKAN TUNA MATA BESAR (Thunnus obesus) DI SAMUDERA HINDIA YANG DIDARATKAN DI PELABUHAN BENOA, DENPASAR, BALI

2017 ◽  
Vol 5 (4) ◽  
pp. 371-380
Author(s):  
Erika Kurniawati ◽  
Abdul Ghofar ◽  
Suradi Wijaya Saputra ◽  
Budi Nugraha
Keyword(s):  
Indian Ocean ◽  
Growth Function ◽  
Von Bertalanffy ◽  
Bigeye Tuna ◽  
Population Parameters ◽  
Thunnus Obesus ◽  
Von Bertalanffy Growth Function ◽  
Exploitation Rate ◽  
The Indian Ocean ◽  
Tuna Longline

ABSTRAK Tuna mata besar (Thunnus obesus) di Samudera Hindia menjadi salah satu target utama penangkapan. Berdasarkan pemanfaatan tersebut, perlu dilakukan penelitian mengenai parameter populasi tuna mata besar. Penelitian ini bertujuan untuk mengetahui aspek pertumbuhan, ukuran pertama kali tertangkap, parameter populasi, laju mortalitas, laju eksploitasi dan pola rekrutmen. Jumlah sampel tuna mata besar sebanyak 648 ekor diambil dari 21 armada rawai tuna (longline) yang melakukan bongkar selama penelitian. Data panjang tahun 2013-2014 diperoleh dari Loka Penelitian Perikanan Tuna Bali. Penelitian ini dilakukan bulan April-Mei 2016 di Pelabuhan Benoa, Denpasar, Bali. Analisis data menggunakan Model Von Bertalanffy Growth Function dengan software FISAT II. Hasil penelitian menunjukkan pola pertumbuhan bersifat allometrik negatif. Faktor kondisi diperoleh sebesar 1,02-1,27. Ukuran pertama kali tertangkap (L50%) sebesar 126,54 cmFL. Persamaan pertumbuhan Von Bertalanffy Growth Function (VBGF) diperoleh Lt=199,5(1 - e 0,22 (t+0,451)), dengan nilai K= 0,22/tahun, nilai t0= -0,451 tahun dan L∞ = 199,5 cmFL. Laju mortalitas penangkapan (F) = 0,51/tahun, lebih besar daripada mortalitas alami (M) = 0,40/tahun, berarti kematian tuna mata besar lebih banyak disebabkan karena faktor eksploitasi/penangkapan. Laju eksploitasi (E)= 0,56 mengindikasikan tuna mata besar yang tertangkap oleh armada rawai tuna (longline) di Samudera Hindia dalam kondisi fully exploited (padat tangkap).Kata Kunci : Ikan tuna mata besar; aspek biologi; umur; pertumbuhan; mortalitas; laju eksploitasi; rekrutmen; Samudera Hindia  ABSTRACT Bigeye tuna (Thunnus obesus) in the Indian Ocean became one of the main targets of arrest. Based on utilization, research is needed on bigeye tuna population parameters. This study aims to determine of growth, size at the first caught, population parameters, mortality rate, exploitation rate and recruitment patterns. Number samples of bigeye tuna were taken from 648 fishes by 21 tuna longline fleets which was unloading during this study. Length data of 2013-2014 were obtained from Research Institute for Tuna Fisheries, Bali. This research was conducted April-May 2016 in Benoa Harbour, Denpasar, Bali. Data analysis used the Von Bertalanffy Growth Function Model with FISAT II software. The results showed negative allometric growth patterns. The condition factor was obtained for 1.02 to 1.27. The length at first caught (L50%) amounted to 126.54 cmFL. VBGF growth equation was obtained Lt=199.5(1 - e 0.22 (t + 0.451)), with the value K=0,22/year, t0= -0,451/year and L∞= 199,5 cmFL. The fishing mortality rate (F)= 0.51/year, it was bigger than the natural mortality (M)= 0.40/year, means that mostly mortality of bigeye tuna was caused by the exploitation / fishing factor. The exploitation rate (E)= 0.56, indicated that bigeye tuna were caught by tuna longline fleets in the Indian Ocean on fully exploited.Keywords:Bigeye tuna; biology aspect; age; growth; mortality; exploitation rate; recruitment; Indian Ocean

scholarly journals Distribution of Bigeye Tuna in the Indian Ocean as Seen from Tuna Longline Catches.

1991 ◽  
Vol 57 (9) ◽  
pp. 1683-1687
Author(s):  
Masahiko Mohri ◽  
Eiji Hanamoto ◽  
Shoichi Takeuchi
Keyword(s):  
Indian Ocean ◽  
Bigeye Tuna ◽  
The Indian Ocean ◽  
Tuna Longline

scholarly journals POPULATION STRUCTURE AND BIOREPRODUCTION OF BIGEYE TUNA (Thunnus obesus) IN WESTERN PART OF SUMATERA AND SOUTHERN PART OF JAVA AND NUSA TENGGARA, INDIAN OCEAN

2015 ◽  
Vol 21 (2) ◽  
pp. 109
Author(s):  
Ali Suman ◽  
Hari Eko Irianto ◽  
Khairul Amri ◽  
Budi Nugraha ◽  
Gatut Bintoro
Keyword(s):  
Population Structure ◽  
Indian Ocean ◽  
Bigeye Tuna ◽  
Spawning Ground ◽  
Thunnus Obesus ◽  
Tuna Fishing ◽  
The Indian Ocean ◽  
Mature Fish ◽  
Immature Fish ◽  
Important Fish

Bigeye tuna is an important fish resource in the Indian Ocean. This species like other tuna species needs to be managed properly in both national and international levels. Therefore some data and information on population structure and bioreproduction are required for management purpose. The current research was conducted to identify the population structure and bioreproduction of bigeye tuna (<em>Thunnus obesus</em>) in west off Sumatera and south off Java and Nusa Tenggara of Indian Ocean where tuna fishing spots are important. This research was based on catch landed by fishermen from the Indian Ocean during 2010. Analysis of population structure was done using DNA genetic analyses and bioreproduction by using histology technique. Results show that the population structure of the bigeye tuna in the Indian Ocean consisted of two different sub populations namely sub population of west off Sumatra and sub population of south of Java and Nusa Tenggara waters. Most of catch (about 39%) was categorized as immature fish (GI I). The immature fish was mostly found in west off Sumatera waters, meanwhile the catch in south off Java and Nusa Tenggara waters was mostly categorized as mature fish. This result may indicate that south off Java and Nusa Tenggara waters is a spawning ground of the bigeye tuna.

Environmental preferences of bigeye tuna, Thunnus obesus, in the Indian Ocean: an application to a longline fishery

2009 ◽  
Vol 85 (2) ◽  
pp. 153-171 ◽  
Author(s):  
Liming Song ◽  
Ji Zhou ◽  
Yingqi Zhou ◽  
Tom Nishida ◽  
Wenxin Jiang ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Longline Fishery ◽  
Bigeye Tuna ◽  
Environmental Preferences ◽  
Thunnus Obesus ◽  
The Indian Ocean
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