scholarly journals Estimates of historic changes in total mortality and selectivity for Eastern Atlantic skipjack (Katsuwonus pelamis) from length composition data

2009 ◽  
Vol 23 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Daniel Gaertner
2021 ◽  
Vol 919 (1) ◽  
pp. 012004
Author(s):  
S Herwaty ◽  
A Mallawa ◽  
Najamuddin ◽  
M Zainuddin

Abstract Skipjack tuna is one of the potential fishery commodities in the waters of Timor, East Nusa Tenggara. This fish is exploited throughout the year without any management policies. This study aims to analyse population dynamic parameter. Length data were collected at the Oeba Fish Base from April to December 2020. Data analysis, size structure and age group of the Bhattacharya method, the L∞ and K values of the Ford and Walford method, total mortality by length catch converted curve, natural mortality by Pauly method, Y/R using the Beverton and Holt method. The results showed that the smallest fish was 27 cm FL, the largest was 71 cm FL, the dominant size is 55-58 cm FL and the average length was 48,68 ± 10,67 cm FL, L∞ 91.00 cm FL, and K 0.51 year1. The population consists of three age groups, the values of Z, M, F and E are 2.64 year1, 0.86 year1, 1.78 year1, and 0.68 year1 respectively. Current Y/R and optimal Y/R values are 0.036 and 0.060 grams recruit1 respectively. The conclusion, the high mortality of skipjack tuna is caused by fishing activities, and the high level of exploitation causes the recruitment process to be not optimal.


2018 ◽  
Vol 9 (3) ◽  
pp. 163
Author(s):  
Raymon Rahmanov Zedta ◽  
Prawira Atmaja Rintar PT ◽  
Dian Novianto Novianto

Penelitian ini bertujuan untuk mengkaji parameter populasi ikan cakalang (Katsuwonus pelamis) yang tertangkap pukat cincin di WPP-572 Samudra Hindia Barat Sumatera dan WPP-573 Selatan Jawa. Hasil penelitian ini diharapkan dapat digunakan sebagai masukan dalam penentuan pengelolaan perikanan sehingga stok ikan cakalang dapat dimanfaatkan secara berkelanjutan. Ikan contoh dikumpulkan melalui program enumerasi tahun 2016 (Januari-Desember). Sampling acak dilaksanakan di empat pelabuhan, yaitu PPS Lampulo (Aceh), PPN Sibolga (Sumatra Utara), PPP Tamperan (Pacitan) dan IPP Pondokdadap (Malang). Jumlah ikan contoh diperoleh sebanyak 14.894 ekor. Serial data fekuensi panjang bulanan diolah menggunakan program FiSAT II untuk menduga parameter pertumbuhan, mortalitas dan tingkat eksploitasi. Hasil penelitian menunjukkan ikan cakalang yang tertangkap di WPP-572 memiliki panjang asimtotik (L)73,5 cmFL, K sebesar 0.22/tahun dan to sebesar -0,59 tahun. Parameter populasi di WPP-573 berturut-turut L”=67,20 cmFL, K=0,27/tahun, dan to=-0,50 tahun. Nilai mortalitas alami (M) ikan cakalang di WPP 572 sebesar 0,49/tahun, mortalitas total (Z) 0,70/tahun, dan kematian akibat penangkapan (F) adalah 0,21/tahun. Ikan cakalang yang tertangkap di WPP 573 menunjukkan nilai (E) sebesar 0,59/tahun, nilai Z 1,02/tahun, dan nilai F sebesar 0,43/tahun. Dugaan tingkat eksploitasi ikan cakalang di WPP 572 dan 573 masing-masing 0,3/tahun dan 0,42/tahun atau belum berada pada tahap optimal.This study aimed to assess the population parameters of skipjack tuna (Katsuwonus pelamis) that caught by purse seine in the Indonesian FMA (Fisheries Management Area) 572 Indian Ocean West Sumatera and FMA 573 South Java. The outcomes of this research can hopefully be used as inputs for fisheries management, in order the stock of skipjack tuna can be utilized sustainably. Fish sample were collected through the program enumeration of Research Institute for Tuna Fisheries (RITF) during the year 2016 (Januari-Desember). Using random sampling method at four fishing ports, namely PPS Lampulo (Aceh), PPN Sibolga (North Sumatra), PPP Tamperan (Pacitan), and IPP Pondokdadap (Malang). The total number of fish samples was 14.894 fish. Monthly length frequency data processed using FiSAT II program to estimate the growth parameters, mortality, and exploitation. The analysis results showed that skipjack tuna caught in FMA 572 has asymtotic length value (L) at 73.5 cmFL, K value 0.22/year, and to at -0.59 year; while in FMA 573 population parameters values respectively 67.20 cmFL, 0.27/year, and -0.50 year. The value of natural mortality (M) skipjack in FMA 572 is 0.49/year, total mortality (Z) 0.70/year, and fishing mortality (F) 0.21/year. Skipjack tuna that caught in FMA 573 showed value of M 0.59/year, Z value 1.02/year, and F value 0.43/year. The estimated values of exploitation levels of skipjack in FMA 572 and 573 were 0.3/year and 0.42/year respectively.


2017 ◽  
Vol 9 (2) ◽  
pp. 113
Author(s):  
Thomas Hidayat ◽  
Tegoeh Noegroho ◽  
Karsono Wagiyo

Ikan cakalang (Katsuwonus pelamis Linnaeus, 1758) merupakan salah satu sumberdaya ikan pelagis besar yang mempunyai nilai ekonomis penting. Informasi mengenai struktur ukuran dan beberapa parameter populasinya masih sangat terbatas khususnya di perairan Indonesia timur. Penelitian ini dilakukan di Morotai, Biak dan Jayapura dari Januari sampai Desember 2013. Tujuan penelitian ini adalah untuk menganalisis ukuran ikan yang tertangkap dan menganalisis parameter populasi meliputi laju pertumbuhan, mortalitas dan tingkat eksploitasi. Estimasi parameter pertumbuhan, mortalitas dan laju eksploitasi dihitung menggunakan program FiSAT (FAO-ICLARM Stock Assessement Tools). Ukuran ikan cakalang hasil tangkapan pancing tonda dan pancing ulur berkisar antara 15 – 94 cmFL (Fork Length), dengan modus antara 40-45 cmFL. Ukuran pertama kali tertangkap sebesar 40,1 cmFL dan kebanyakan adalah ukuran ikan yang sedang memijah. Hasil analisis menggunakan FiSAT II diperoleh laju pertumbuhan (K) sebesar 0,41/tahun, panjang asimptotik (L) 101,85 cmFL. Laju kematian alami (M) 0,6 / tahun, laju kematian karena penangkapan (F) 0,62 /tahun dan laju mortalitas total (Z) 1,22 /tahun. Tingkat eksploitasi ikan cakalang hampir fully exploited (E= 0,46). Disarankan tidak perlu ada penambahan upaya penangkapan atau status quo untuk menjaga agar sumberdaya ikan cakalang tetap terjaga kelestariannya. Skipjack tuna (Katsuwonus pelamis Linnaeus, 1758) is one of the large pelagic fish resources which have high economic value. Information on the size structure and population parameters is still limited especially in the waters of eastern Indonesia. The Research was conducted from January to December 2013 at Morotai, Biak and Jayapura. The aim of this study was to analyze the size of the fish caught and some of population parameters such as the growth rate, mortality rates, and exploitation rate. Estimated of growth parameters, mortality and exploitation rate using the program FiSAT (FAO-ICLARM Stock Assessement Tools). The size of skipjack tuna caught by troll line and handline in between 15-94 cmFL, with a mode of 40-45 cmFL. The Length at first capture was 40.1 cmFL, most of them had condition of spawning. By using program FiSAT II analysis resulted that growth rate (K) of skipjack tuna was 0.41/year, with length asimptotik (L) reaches 101.85 cmFL. The natural mortality rate (M) was 0.6 / year. The fishing mortality rate (F) was 0.62 / year and total mortality rate (Z) was 1.22 / year. The exploitation rate of skipjack tuna was nearly fully exploited (E = 0.46). It was recommended the exploitation rate of this fish should be no additional effort (status quo) to keep sustainability of the skipjack tuna resource.


2012 ◽  
Vol 82 (3) ◽  
pp. 209-215 ◽  
Author(s):  
Simone Bell ◽  
Heikki Pakkala ◽  
Michael P. Finglas

Food composition data (FCD) comprises the description and identification of foods, as well as their nutrient content, other constituents, and food properties. FCD are required for a range of purposes including food labeling, supporting health claims, nutritional and clinical management, consumer information, and research. There have been differences within and beyond Europe in the way FCD are expressed with respect to food description, definition of nutrients and other food properties, and the methods used to generate data. One of the major goals of the EuroFIR NoE project (2005 - 10) was to provide tools to overcome existing differences among member states and parties with respect to documentation and interchange of FCD. The establishment of the CEN’s (European Committee for Standardisation) TC 387 project committee on Food Composition Data, led by the Swedish Standards Institute, and the preparation of the draft Food Data Standard, has addressed these deficiencies by enabling unambiguous identification and description of FCD and their quality, for dissemination and data interchange. Another major achievement of the EuroFIR NoE project was the development and dissemination of a single, authoritative source of FCD in Europe enabling the interchange and update of data between countries, and also giving access to users of FCD.


1995 ◽  
Author(s):  
Dennis E. Delorey ◽  
Paul N. Pruneau ◽  
John R. Palys

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