Changes in habitat preference of tuna species and implication for regional fisheries management: southern bluefin tuna fishing in the Indian Ocean

2016 ◽  
Vol 8 (2) ◽  
pp. 117-131
Author(s):  
Eldene James Alan O’Shea
Keyword(s):  
Indian Ocean ◽  
Fisheries Management ◽  
Habitat Preference ◽  
Bluefin Tuna ◽  
Southern Bluefin Tuna ◽  
Tuna Fishing ◽  
The Indian Ocean ◽  
Regional Fisheries Management

scholarly journals COMPARISON OF INDONESIAN TUNA LONGLINE FISHING PERFORMANCE WITHIN AND OUTSIDE INDONESIA EXCLUSIVE ECONOMIC ZONE (EEZ)

2017 ◽  
Vol 23 (1) ◽  
pp. 1
Author(s):  
Bram Setyadji ◽  
Irwan Jatmiko
Keyword(s):  
Indian Ocean ◽  
Bluefin Tuna ◽  
T Test ◽  
Exclusive Economic Zone ◽  
Southern Bluefin Tuna ◽  
The Indian Ocean ◽  
The Mean ◽  
Economic Zone ◽  
Tuna Longline ◽  
High Seas

Indonesian tuna longline fleets have been fishing in the Exclusive Economic Zone (EEZ) and high seas of the Indian Ocean for quite some time. However, effort has never been made to separate catch from the EEZ and the high seas as it important for fisheries management. A total of 2,430 set-by-set longline fishing data had been collected by scientific observers based in the Research Institute of Tuna Fishery in Bali since August 2005 to December 2014 on which present analysis was made. The research aims to compare between trend of tuna catch of the EEZ and of the high seas of Indian Ocean. The results show that the mean hook rate of both catches of big eye tuna (BET) and southern Bluefin tuna (SBT) caught in the high seas was significantly higher than that the EEZ (two sample t-test, p<0.05), while for yellow fin tuna (YFT) it was in the opposite direction (two sample t-test, p<0.05). As for albacore (ALB), the mean hook rate value was statistically similar in both fishing grounds (two sample t-test, p>0.05).

scholarly journals STATUS SUMBER DAYA IKAN TUNA SAMUDERA HINDIA: IMPLIKASINYA BAGI INDONESIA

2017 ◽  
Vol 1 (1) ◽  
pp. 31
Author(s):  
Victor P. H. Nikijuluw
Keyword(s):  
Open Access ◽  
Indian Ocean ◽  
Fisheries Management ◽  
Fishing Ground ◽  
Small Species ◽  
Management Regime ◽  
The Future ◽  
The Indian Ocean ◽  
Management Organization ◽  
Regional Fisheries Management

Sumber daya ikan tuna di Samudera Hindia dikelola oleh 2 Regional Fisheries Management Organization yaitu Indian Ocean Tuna Commission dan Commission for the Conservation of the Blue Fin Tuna. Dengan pengolahan ini, maka sumber daya ini tidak lagi bebas dimasuki untuk dimanfaatkan, kecuali oleh negara atau entitas yang menjadi anggota ke-2 Regional Fisheries Management Organization ini. Sumber daya tuna ini telah dimanfaatkan sejak tahun 1950, dan mungkin akan terus menjadi daerah penangkapan utama di masa mendatang. Jenis-jenis tuna ukuran besar sudah cenderung ditangkap secara berlebihan. Sementara jenis tuna ukuran kecil cenderung belum tinggi intensitas penangkapan. Indonesia sudah saatnya mengembangkan perikanan tuna di Samudera Hindia ini secara besar-besaran, mengingat posisi geografis Indonesia yang relatif lebih dekat dan berbatasan langsung dengan Samudera Hindia.Indian Ocean tuna resources are managed by two Regional Fisheries Management Organization; the Indian Ocean Tuna Commission and Commission for the Conservation of the Blue Fin Tuna. Under this management regime, the fishery is not an open access. It can only be utilized by member countries and entities of the those Regional Fisheries Management Organization. The tuna resources have been extensively caught since 1950, and may be kept on being exploited in the future. The large tuna species tended to have been fully utilized, while the small species may be considered under fished. Indonesia should develop its capacity to the best use of the existing resources, considering its relatively shorter distance to the fishing ground.

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.

scholarly journals Sustainable Fisheries Management in the Indian Ocean: The Way Forward

2019 ◽  
Vol 1 (1) ◽  
pp. 1-14
Author(s):  
Jayanath Colombage
Keyword(s):  
Indian Ocean ◽  
Fisheries Management ◽  
Life Support ◽  
Large Population ◽  
Human Security ◽  
Economic Activities ◽  
Fisheries Resources ◽  
Iuu Fishing ◽  
Terrorist Groups ◽  
The Indian Ocean

The Oceans cover 71% of the earth’s surface and contains 97% of the planet’s water. This is the life support system of the earth. The Ocean is the main protein supplier for the humankind. The Indian Ocean is a warm water ocean and well regulated by monsoons and currents. Large number of rivers and tributaries flow into this ocean, making it rich with minerals, seaweeds and planktons, which sustain the fish stocks. Man-made pollution and climate change can be detrimental to the sustenance of a balanced marine eco-system. Further, Illegal, Unreported and Unregulated (IUU) fishing combined with destructive fishing methods can deplete this valuable protein source. Issues and conflicts in delimitation of maritime boundaries and fishermen not respecting even internationally or bilaterally established maritime boundaries are impediments to effective fisheries management. The Indian Ocean is vast and the third largest ocean in the world. The population of the Indian Ocean is around 2.5 billion. However, we must be mindful of the need to have a sustainable ocean based economic model, that will not over exploit the finite fishery resources but will continue to provide the much-needed protein sources to this large population, not only at present times but even in the future. Non-management of fisheries by states and non-adherence to rule based maritime order by non-state actors engaged in fisheries could have ramifications on traditional and human security aspects for the region. Fishing boats and some fishermen could be involved with various maritime crime activities for monetary or ideological gains, and, depletion of fisheries resources due to overfishing can have a direct impact on human security of the Indian Ocean littorals, as the main livelihood and economic activities of the coastal populations are connected to the ocean based resources. There were many instances of the fishermen being exploited by terrorist groups. Hence the management of fisheries in a sustainable manner is important for the Indian Ocean, as the peaceful co-existence of the nations depends on the continued Blue Economic models where the fisheries is managed and harvested in a sustainable manner.

scholarly journals TINGKAT EKSPLOITASI IKAN TUNA SIRIP BIRU SELATAN (Thunnus maccoyii) DI SAMUDERA HINDIA BERDASARKAN HASIL TANGKAPAN YANG DIDARATKAN DI PELABUHAN BENOA, BALI

2016 ◽  
Vol 5 (4) ◽  
pp. 345-352
Author(s):  
Damar Nusawicaksono Kurniawan ◽  
Abdul Ghofar ◽  
Suradi Wijaya Saputra ◽  
Bram Setyadji
Keyword(s):  
Growth Rate ◽  
Size Structure ◽  
Stock Assessment ◽  
Total Mortality ◽  
Bluefin Tuna ◽  
Fisheries Resources ◽  
Southern Bluefin Tuna ◽  
The Indian Ocean ◽  
Data Length ◽  
Length Frequency Data

ABSTRAK Pengkajian dan pendugaan status sumberdaya perikanan di suatu wilayah perairan dapat dilakukan dengan mengetahui laju eksploitasinya. Data frekuensi panjang merupakan salah satu data yang dapat digunakan untuk melakukan pendugaan tingkat eksploitasi tersebut. Penelitian ini bertujuan untuk menduga nilai mortalitas, laju pertumbuhan, ukuran pertama kali tertangkap dan tingkat eksploitasi. Penelitian dilakukan pada bulan April-Mei 2016 di Loka Penelitian Perikanan Tuna Pelabuhan Benoa, Denpasar, Bali. Metode yang digunakan adalah metode survei. Sementara data panjang ikan tuna sirip biru selatan tahun 2013-2014 kemudian diolah dengan perangkat lunak FISAT II. Hasil penelitian menunjukkan struktur ukuran ikan tuna sirip biru selatan 145 - 210 cmFL dengan modus di ukuran 170-174 cmFL, ukuran pertama kali tertangkap (Lc) 171 cmFL, hubungan panjang berat mendapat nilai W= 0,00006*FL2,792, faktor kondisi berada pada angka 1,86-2,00, laju pertumbuhan yang didapat yaitu Lt=220,50(1 - e 0,2(t+0,488)), dimana nilai dari L∞ yaitu 220,50 cmFL dan nilai t0 -0,49, laju mortalitas total (Z) sebesar 1,14/tahun, laju mortalitas alami (M) sebesar 0,36/tahun, dan laju mortalitas akibat penangkapan (F) sebesar 0,78/tahun, dan tingkat eksploitasi (E) 0,68/tahun, Hal ini menunjukan penangkapan  ikan tuna sirip biru selatan oleh kapal rawai tuna di Samudera Hindia dalam keadaan berlebih (overfishing) karena nilai tingkat eksploitasi yang didapat melebihi tingkat pemanfaatan optimum atau Eopt = 0,5/tahun (0,68 > 0,5). Kata Kunci : Ikan Tuna Sirip Biru Selatan, Tingkat Eksploitasi, Mortalitas, Pertumbuhan  ABSTRACT Stock assessment and prediction status of fisheries resources in the waters can be made by knowing the rate of exploitation. Length-frequency data is one can be used to suspect rate of exploitation . The aimed of this research was to suspect value of mortality, the growth rate, size at first capture and the level of exploitation. This research was conducted on April-May 2016 at the Loka Fishery Tuna's Research Benoa Port, Denpasar, Bali. This research used survey method.While data length of the southern bluefin tuna 2013-2014 was processed with FISAT II. The results showed size structure of southern bluefin tuna 145-210 cmFL with mode in sizes 170-174 cmFL, size at first capture (Lc) 171 cmFL, value of lenght and weight relationship W = 0,00006 *,792 FL2, condition factors 1,86-2.00, the growth rate Lt = 220,50 (1-e of 0.2 (t + 0,488)), where the value of L ∞ was 220.50 cmFL and value t0 -0.49 total mortality rate (Z) of 1.14/year, rate of natural mortality (M) of 0.36/year, and  rate of mortality due to the arrest of (F) amounted to 0.78/year, and the rate of exploitation (E) 0,68/year, it shows the fishing of southern bluefin tuna by the longline in the Indian Ocean was overfishing because level of exploitation value was over the optimum effort or Eopt = 0,5/year (0.68 > 0.5). Keyword: Southern Bluefin Tuna, exploitation rate, Mortality, growth,

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