scholarly journals A Statistical Model for Stock Assessment of Southern Bluefin Tuna with Temporal Changes in Selectivity

2003 ◽  
Vol 25 (1) ◽  
pp. 331-361 ◽  
Author(s):  
D. S. Butterworth ◽  
J. N. Ianelli ◽  
R. Hilborn
Keyword(s):  
Statistical Model ◽  
Stock Assessment ◽  
Bluefin Tuna ◽  
Temporal Changes ◽  
Southern Bluefin Tuna

Increase in growth rates of southern bluefin tuna (Thunnus maccoyii) over four decades: 1960 to 2000

2004 ◽  
Vol 61 (2) ◽  
pp. 307-322 ◽  
Author(s):  
Tom Polacheck ◽  
J Paige Eveson ◽  
Geoff M Laslett
Keyword(s):  
Stock Assessment ◽  
Temporal Trends ◽  
Integrated Approach ◽  
Bluefin Tuna ◽  
Fish Stocks ◽  
Southern Bluefin Tuna ◽  
History Of ◽  
The 1960S ◽  
Length Frequency Data

Estimates of long-term temporal trends and variability in growth are often not available for many commercially exploited fish stocks. An integrated estimation framework that combines growth information from tagging studies, direct age estimates from hard parts, and modal progression estimates from length–frequency data is applied to data on southern bluefin tuna (Thunnus maccoyii, SBT) collected over four decades, from 1960 to 2000. By using an integrated approach, a comprehensive set of growth estimates can be obtained for each of these four decades even though substantive deficiencies exist in the coverage of the historical data from any single source. The results confirm previous findings that cohorts from the 1980s grew substantially faster at young ages than cohorts from the 1960s. The results also suggest that the 1970s was a period of transition and that growth of fish up to about age 4 was faster in the 1990s than in the 1980s. The changes in SBT growth over these four decades are consistent with density-dependent responses given the history of exploitation and stock assessment estimates of changes in population size.

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,

Stock Assessment of the Southern Bluefin Tuna Thunnus maccoyii Using the MULTIFAN-CL Model

2007 ◽  
Vol 40 (6) ◽  
pp. 367-373
Author(s):  
You-Jung Kwon ◽  
Dae-Yeon Moon ◽  
Chang-Ik Zhang ◽  
Jeong-Rack Koh
Keyword(s):  
Stock Assessment ◽  
Bluefin Tuna ◽  
Southern Bluefin Tuna

The Australia and New Zealand v Japan Southern Bluefin Tuna (Jurisdiction and Admissibility) Award of the First Law of the Sea Convention Annex VII Arbitral Tribunal

2001 ◽  
Vol 16 (2) ◽  
pp. 239-293 ◽  
Author(s):  
Barbara Kwiatkowska
Keyword(s):  
New Zealand ◽  
Bluefin Tuna ◽  
Fundamental Principle ◽  
Law Of The Sea ◽  
Arbitral Tribunal ◽  
Compulsory Arbitration ◽  
Wide Range ◽  
The Future ◽  
Questions And Answers ◽  
Southern Bluefin Tuna

AbstractThe Southern Bluefin Tuna (Jurisdiction and Admissihilily) Award of 4 August 2000 marked the first instance of the application of compulsory arbitration under Part XV, Section 2 of the 1982 UN Law of the Sea Convention and of the exercise by the Annex VII Tribunal of la compétence de la compétence pursuant to Article 288(4) over the merits of the instant dispute. The 72-paragraph Award is a decision of pronounced procedural complexity and significant multifaceted impacts of which appreciation requires an in-depth acquaintance with procedural issues of peaceful settlement of disputes in general and the-law-of-the-sea-related disputes in particular. Therefore, the article surveys first the establishment of and the course of proceedings before the five-member Annex VII Arbitral Tribunal, presided over by the immediate former ICJ President, Judge Stephen M. Schwebel, and also comprising Judges Keith, Yamada. Feliciano and Tresselt. Subsequently, the wide range of specific paramount questions and answers of the Tribunal are scrutinised against the background of arguments advanced by the applicants (Australia and New Zealand) and the respondent (Japan) during both written and oral pleadings, including in reliance on the extensive ICJ jurisprudence and treaty practice concerned. On this basis, the article turns to an appraisal of the impacts of the Arbitral Tribunal's paramount holdings and its resultant dismissal of jurisdiction with the scrupulous regard for the fundamental principle of consensuality. Amongst such direct impacts as between the parties to the instant case, the inducements provided by the Award to reach a successful settlement in the future are of particular importance. The Award's indirect impacts concern exposition of the paramount doctrine of parallelism between the umbrella UN Convention and many compatible (fisheries, environmental and other) treaties, as well as of multifaceted, both substantial and procedural effects of that parallelism. All those contributions will importantly guide other courts and tribunals seised in the future under the Convention's Part XV, Section 2.

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