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"Tuna mata besar merupakan komoditas ekspor. Di PPN Palabuhanratu tuna merupakan hasil tangkapan dominan. Jenis tuna yang terbanyak didaratkan adalah tuna mata besar. Untuk itu perlu dilakukan penelitian mengenai status perikanan tuna mata besar. Pengumpulan data dilakukan dengan metode sampling bertujuan. Jumlah sampel tuna mata besar sebanyak 397 ekor diambil secara acak pada armada longline yang siap melakukan bongkar. Analisis data menggunakan surplus produksi dan Model Von Bertallanfy Growth Function. Hasil penelitian menunjukkan bahwa produktivitas tuna mata besar yang didaratkan di PPN Palabuhanratu mengalami kecenderungan yang meningkat. Pola pertumbuhan tuna mata besar bersifat allometrik negatif dengan bentuk tubuh kurang pipih. Tuna mata besar yang tertangkap sudah berumur sekitar 2 tahun dan sudah mengalami fase pemijahan. Tingkat pemanfaatan tuna mata besar sudah padat tangkap (82,43 %), sedangkan tingkat pengusahaan sudah lebih tangkap (104,21 %).

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Bigeye Tuna is an export commodity. Tuna is the predominant catches in PPN Palabuhanratu. Species of tuna that ever landed was a bigeye tuna. Therefore, need to do studies about the status of the bigeye tuna. Data collection is conducted by purposive sampling. The number of bigeye tuna samples are 397 taken at random on the longline fleet ready unloaded. Data analysis using the surplus production and Von Bertallanfy Growth Model funcion.

The results showed that the productivity of the bigeye tuna landed in PPN Palabuhanratu experiencing an upward trend. Bigeye tuna pattern of growth is negative allometrik with less flattened body shape. Bigeye tuna caught about 2 years old and has been through a phase of spawning. Utilization rate of bigeye tuna is already intense capture (82.43%), while the rate of operation already overfishing (104.21%)."

"Ikan tongkol lurik Euthynnus affinis, (Scombridae) merupakan ikan besar yang banyak tertangkap di perairan Laut Jawa. Penelitian ini bertujuan untuk mengetahui komposisi sebaran ukuran ikan tongkol, panjang pertama kali tertangkap, hubungan panjang-berat, pola pertumbuhan, kebiasaan makanan, nisbah kelamin, Tingkat Kematangan Gonad (TKG), Indeks Kematangan Gonad, fekunditas dan diameter telur ikan tongkol yang didaratkan di PPI Labuan. Pengambilan sampel dilakukan pada bulan Mei, Juni, dan September 2012.Hasil penelitian menunjukkan bahwa sebaran frekuensi panjang cagak ikan tongkol yang ditangkap berkisar 38-69 cm ( x = 50 cm). Ukuran pertama kali tertangkap 47,8 cm dengan panjang cagak ikan yang paling banyak tertangkap berkisar 49-51 cm. Hubungan panjang-berat ikan tongkol bersifat allometrik negatif. Ikan tongkol memakan ikan pelagis kecil, cumi dan teri. Nisbah kelamin antara ikan jantan : betina (1:1,4). Tingkat Kematangan Gonad ikan termasuk TKG III dan IV hal ini menunjukkan bahwa ikan dalam masa pemijahan. Indeks Kematangan Gonad rata-rata adalah 4,55%. Faktor kondisi berkisar antara 1,38-2,22. Fekunditas telur berkisar antara 852.000 - 2.056.609 butir dengan rata-rata 1.352.382 butir. Sedangkan diameter telur berkisar 1,28 - 1,8 mm.

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Eastern little tuna Euthynnus affinis (Scombridae) is a pelagic fish which caught excessively in the Java Sea waters. The objective of this research is to determine the composition of these tuna size distribution, lenght at first capture, length-weight relationship, growth pattern, food content, sex ratio, gonad maturity level, gonado stomatic index, fecundity and eggs with diameter of their kind of fish caught and landed in PPP Labuan. Sampling was conducted in May, June and September 2012.The results showed that the frequency distribution of fork lenght caught ranged 38-69 cm (x =50 cm). Size of lenght at first capture is 47.8 cm and most of them ranging from 49-51 cm. Length-weight relationship is allometric negative. The food of this fish species are small pelagic fish, squid and anchovies. Sex ratio the male: female (1:1.4). Gonad maturity level of fish at TKG III and IV indicating that the fishes are in the spawning seasons. Gonad Maturity Index is 4.55%. The condition factor ranged from 1.38 to 2.22. Fecundity ranged from 852,000 - 2,056,609 eggs (average 1,352,382 eggs). While the eggs diameter ranged from 1.28 to 1.8 mm."

"Salah satu aspek untuk mendukung upaya pengelolaan sumberdaya ikan adalah pengetahuan mengenai aspek biologi. Ketersediaan data aspek biologi memiliki arti penting sebagai upaya kajian pengelolaan sumber daya ikan tuna sirip kuning di Samudera Hindia. Aspek biologi reproduksi ikan tuna tuna sirip kuning merupakan permasalahan yang penting diteliti, dengan melalui pola pertumbuhan, faktor kondisi dan masa pemijahan. Sampel ikan tuna sirip kuning diperoleh dari Pelabuhan Benoa-Bali. Data panjang-berat, fekunditas dan nilai kematangan gonad diolah dengan menggunakan analisis fungsi regresi. Hasil pengamatan sampel (870 ekor) pada bulan April dan Mei 2011, panjang cagak rata-rata >130 cm dengan faktor kondisi rata-rata 1,00. Indeks kematangan gonad tertinggi 1,3 %. Ikan tuna sirip kuning di Samudera Hindia dinyatakan pernah mengalami pemijahan, namun belum siap untuk kembali melakukan pemijahan. Dari fungsi regresi menggambarkan pengaruh yang nyata dan keeratan yang tinggi (95 %) pertambahan panjang terhadap pertambahan berat ikan tuna sirip kuning di Samudera Hindia. Selanjutnya, pertambahan berat ikan tidak memberikan pengaruh yang nyata terhadap fekunditas, sedangkan berat gonad memberikan pengaruh yang nyata terhadap nilai kematangan gonad dengan keeratan yang tinggi (88 %).

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One aspect to support the management of fish resources is knowledge about the biological aspects. Data availability of iological aspects has significance as an effort to management study the fish resources of yellowfin tuna in the Indian Ocean. Reproductive biology aspects of yellowfin tuna is an important problem that was studied, with the pattern of growth, condition factor and spawning time. Yellowfin tuna fish samples obtained from the Benoa Fishing Port, Bali. Length-weight data, fecundity and gonad maturity value processed using regression analysis function. The results of sample observations (870 head) in April and May 2011, the average fork length >130 cm with an average condition factor of 1.00. The highest gonad maturity index was 1.3%. Yellowfin tuna in the Indian Ocean have experienced otherwise spawning, but not yet ready to return to spawning. From the regression function describes a real influence and high closeness (95%) of fish length against weight of yellowfin tuna in the Indian Ocean. Furthermore, the added fish weight does not give significant effect on fecundity, whereas gonad weight while providing a noticeable effect of the gonad maturity with a high closeness (88%)."

"ABSTRAKIkan tuna mata besar (Thunnus obesus LOWE, 1839) merupakan ikanpelagis besar yang mempunyai nilai ekonomis yang sangat penting sebagaihasil tangkapan kapal rawai tuna di Pelabuhan Benoa, Bali. Hasil tangkapantuna mata besar yang didaratkan di Pelabuhan Benoa, Bali mengalamipenurunan. Penelitian ini bertujuan untuk memperoleh informasi tentangaspek biologi dan mengestimasi status pengelolaan sumberdaya tuna matabesar hasil tangkapan rawai tuna di Pelabuhan Benoa, Bali.Metodepenelitian yang dilakukan meliputi pengukuran aspek biologi, CPUE danMSY. Berdasarkan analisa aspek biologi diduga bahwa ikan tuna mata besaryang ditangkap pada bulan April-Mei telah melewati masa pijah, polapertumbuhan ikan tuna mata besar bersifat isometrik yang berartipetumbuhan panjang sama dengan pertumbuhan berat. Hubungan antaraupaya penangkapan dan CPUE menunjukkan bahwa nilai CPUE naik apabilaterjadi penambahan alat tangkap. Berdasarkan Single Quantitative Modellingmethod (ASPM) diperkirakan nilai MSY ikan tuna mata besar adalah103.000 ton. Jumlah rata-rata tangkapan pada tahun 2007-2011 sebesar101.639 ton. Nilai tersebut masih dibawah nilai MSY yang berarti belumterjadi tangkap lebih ikan tuna mata besar.

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ABSTRACTBigeye tuna, Thunnus obesus, is the most commercially economicimportant pelagic fish resources which is the main target of the pelagiclongline fisheries landing at Benoa Fishing Port in Bali Province. However,the production of bigeye tuna at Benoa Fishing Port has shown the decliningtrend in the past years. The objectives of this research are to get someinformation on biological aspects and to estimate the status of big eye tunamanagement which was landed at Benoa Fishing Port. The methodologyincludes the measurement of biological aspects. Bigeye tunas were caughtin April-May has passed the spawning time. The growth patterns of thebigeye tuna are isometric, which means that the increasing length was thesame with weight. Based on the Single Quantitative Modeling methology(ASPM) MSY bigeye tuna was estimated at 103.000 tons. Average numberof catches in 2007-2011 was 101.639 tons. As this value is still below theaverage value of MSY, so it can be concluded that the overfishing of bigeyetuna has yet occured."

"Sebagai negara yang memiliki potensi di sektor kelautan yang sangat besar, ternyata kontribusi investasi di sektor perikanan masih di bawah 1% dari investasi nasional. Oleh sebab itu upaya-upaya yang bertujuan untuk memperbaiki kondisi di sektor perikanan menjadi salah satu prioritas di dalam strategi pembangunan oleh pemerintah saat ini. Penelitian ini dilakukan di salah satu wilayah Indonesia yang memiliki potensi laut cukup besar yaitu Kabupaten Gunungkidul. Secara lebih spesifik penelitian ini memfokuskan pada sektor ikan tuna.Untuk itu beberapa pertanyaan penelitian yang perlu dijawab seperti apakah sub sektor perikanan komoditi Tuna di Kabupaten Gunungkidul merupakan sektor yang memiliki daya saing? Bagaimana kondisi daya saing komoditas tuna di Kabupaten Gunungkidul? Faktor-faktor apa saja yang menjadi penghambat pengembangan sub sektor perikanan komoditi tuna di Kabupaten GunungKidul? Dan bagaimana hubungan antara komponen penentu daya saing komoditas tuna di Kabupaten Gunungkidul? Menjadi pertanyaan kunci yang dieksplorasi dalam penelitian ini. Metodologi yang digunakan dalam penelitian ini adalah metode kualitatif. Penelitian kualitatif dengan format deskriptif.Berdasarkan hasil penelitian dapat disimpulkan bahwasanya; komoditas ikan tuna di Kabupaten Gunungkidul memiliki keunggulan kompetitif; Kondisi daya saing komoditas ikan tuna di Kabupaten Gunungkidul pada factor kondisi: sumber daya manusia dan infrastruktur masih perlu mendapatkan perhatian lebih besar, faktor-faktor yang menjadi penghambat adalah kemampuan sumberdaya manusia masih rendah, produksi ikan tuna belum mampu memenuhi permintaan, infrastruktur dan fasilitas perlu banyak perbaikan untuk menghasilkan kualitas ikan tuna yang tinggi, Pengolahan ikan terkendala pengadaan bahan baku dan akses pasar dan belum didukung ketersediaan industri pendukung; Selain itu keterkaitan antar komponen utama saling mendukung kecuali kondisi permintaan dengan sumberdaya, dengan industri terkait dan pendukung, dan dengan struktur pasar, persaingan, dan strategi perusahaan.

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Indonesia has a big potential for the marine sector, but unfortunately it doesn`t follow with the significant contribution from its. Based on the current data base, only 1 % the contribution from national investment, therefore Indonesian government put more effort to fix and develop the marine sector. This research has conducted in Gunungkidul as one of potential area in marine sector in Indonesia, and the scope of research is Tuna fish. To elaborate all informations in terms of Tuna, several key questions has developed as a guidance to do research for instance whether Tuna sector in Gunungkidul has a competitive advantage? How is the form of the competitive advantage of Tuna? What are factors that can be obstacles for Tuna sector development in Gunungkidul? And how is the relation among each component based on Porter theory? The methodology that has been used for this research was decretive qualitative method. Based on the result findings, the Tuna sector in Gunungkidul district has a competitive advantage; nevertheless there are some issues that need to be improve for the better development in Tuna sector for instance the quality of human resources, infrastructures, post-harvest technology and market. However, the relation among each components are supporting each other except component of demand condition with firm strategy rivalry.;Indonesia has a big potential for the marine sector, but unfortunately it doesn`t follow with the significant contribution from its.Based on the current data base, only 1 % the contribution from national investment, therefore Indonesian government put more effort to fix and develop the marine sector. This research has conducted in Gunungkidul as one of potential area in marine sector in Indonesia, and the scope of research is Tuna fish. To elaborate all informations in terms of Tuna, several key questions has developed as a guidance to do research for instance whether Tuna sector in Gunungkidul has a competitive advantage? How is the form of the competitive advantage of Tuna? What are factors that can be obstacles for Tuna sector development in Gunungkidul? And how is the relation among each component based on Porter theory? The methodology that has been used for this research was decretive qualitative method. Based on the result findings, the Tuna sector in Gunungkidul district has a competitive advantage; nevertheless there are some issues that need to be improve for the better development in Tuna sector for instance the quality of human resources, infrastructures, post-harvest technology and market. However, the relation among each components are supporting each other except component of demand condition with firm strategy rivalry."

"ABSTRAKIkan tongkol lisong (Auxis rochei, Risso 1810) dari penelitian ini adalahsalah satu ikan pelagis suku Scombridae. Penelitian dilakukan terhadap ikan iniyang tertangkap di wilayah perairan neritik Teluk Palabuhanratu. Kisaran panjangtotal ikan tongkol lisong antara 12,3 cm sampai dengan 28,5 cm dan cenderungmenyebar normal dengan modus panjang pada ukuran antara 13,5; 19,5; 21,5; dan23,5 cm. Hubungan panjang-berat ikan tongkol lisong bersifat isometric dengankoefisien determinasi sebesar 0,880. Tongkol lisong memiliki panjang infiniti29,93 cm, koefisien pertumbuhan 0,69 per tahun, dan umur teoritis -0,23381. Nilailaju mortalitas total 3,08 per tahun, mortalitas alami 1,12 per tahun, mortalitaspenangkapan 1,68 per tahun dan laju eksploitasi 0,64 per tahun.

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ABSTRACTBullet tuna (Auxis rochei, Risso 1810) is one of the pelagic fish ofScombridae. The study is on this scienc of fish tribe in the neritic territorial watersof the Gulf of Palabuhanratu. The range of total length of bullet tuna are between12.3 cm to 28.5 cm and tend to spread to normal with long mode in size between13.5; 19.5; 21.5; and 23.5 cm. Length-weight relationship this bullet tuna anddetermination coefficient is 0.880. This bullet tuna has infinity length of 29,93cm, coefficient of 0.69 per year growth, and theoretical age -0.23381. The valueof the total mortality rate is 3.08 per year, the natural mortality is 1.12 per year,the fishing mortality of 1.68 per year and the rate of exploitation of 0.64 per year."

"[ABSTRAKDalam penelitian ini dilakukan kompilasi studi literatur kondisi oseanografi berupa suhu dan kedalaman yang sesuai dengan lokasi potensial fishing ground ikan tuna di Samudera Hindia Bagian Timur. Kompilasi studi literatur menghasilkan basis pengetahuan (knowledge based), disusun melalui analisis studi literatur dengan metode plot dan poligon untuk 4 spesies tuna (tuna mata besar, tuna madidihang, tuna albakora, dan tuna sirip biru selatan). Rancangan poligon menunjukkan bahwa tuna albakora potensial tertangkap pada kedalaman 8 - 250 m dengan suhu 16,00 - 26,36 0C, tuna madidihang 42,70 - 340,30 m dengan suhu 14,02 - 27,97 0C, tuna mata besar 48,63 - 466,51 m dengan suhu 8,79 - 29,13 0C, tuna sirip biru pada kedalaman 52 - 492 m dengan suhu 8,14 - 19,86 0C. Poligon divalidasi dengan mempergunakan data tangkapan tuna harian selama 3 hari pada lokasi berbeda berdasarkan koordinat lintang dan bujur. Data insitu suhu dan kedalaman diperoleh melalui Infrastructure Development of Space Oceanography (INDESO) dan Global Ocean Data Asimilation Experinment (GODAE) selama 1 bulan (Januari 2015). Proses interpolasi pada poligon dilakukan untuk mendapatkan kritera suhu dan kedalaman yang dipergunakan pada rancangan peta tematik 3D. Pada bagian akhir penelitian terdapat rekomendasi rancangan alur logika perancangan sistem informasi lokasi potensial fishing ground tuna untuk implementasi model 3D.

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ABSTRACTIn this research, compilation of literature studies consisting of oceanographic conditions (temperature and depth) which appropriate with potential location of tuna fishing ground in Eastern Indian Ocean had been done. These compilation then were analyzed using plot and polygon methods for 4 tuna species (bigeye tuna, yellowfin tuna, albacore tuna and southern bluefin tuna). Based on polygon method, it showed that albacore tuna were potentially caught at depth of 8 - 250 m and at temperature of 16,00 - 26,36 0C, yellowfin tuna at 42,70 - 340,30 m and 14,02 - 27,97 0C, bigeye tuna at 48,63 - 466,51 m and 8,79 - 29,13 0C, southern Bluefin tuna at 52 - 492 m and 8,14 - 19,86 0C. These polygon were validated using tuna fishing capture information for 3 days at different location based on their coordinates (latitude and longitude). In situ data on temperature and depth were obtained from the Infrastructure Development of Space Oceanography (INDESO) and the Global Ocean Data Assimilation Experiment (GODAE) for one month (January 2015). Interpolation process had been done to obtain temperature and depth criteria that were used in 3D thematic mapping design. At the end of the research, there is a recommendation in designing of logical flow of information system on location that were potential for tuna fishing ground using 3D model implementation., In this research, compilation of literature studies consisting of oceanographic conditions (temperature and depth) which appropriate with potential location of tuna fishing ground in Eastern Indian Ocean had been done. These compilation then were analyzed using plot and polygon methods for 4 tuna species (bigeye tuna, yellowfin tuna, albacore tuna and southern bluefin tuna). Based on polygon method, it showed that albacore tuna were potentially caught at depth of 8 - 250 m and at temperature of 16,00 - 26,36 0C, yellowfin tuna at 42,70 - 340,30 m and 14,02 - 27,97 0C, bigeye tuna at 48,63 - 466,51 m and 8,79 - 29,13 0C, southern Bluefin tuna at 52 - 492 m and 8,14 - 19,86 0C. These polygon were validated using tuna fishing capture information for 3 days at different location based on their coordinates (latitude and longitude). In situ data on temperature and depth were obtained from the Infrastructure Development of Space Oceanography (INDESO) and the Global Ocean Data Assimilation Experiment (GODAE) for one month (January 2015). Interpolation process had been done to obtain temperature and depth criteria that were used in 3D thematic mapping design. At the end of the research, there is a recommendation in designing of logical flow of information system on location that were potential for tuna fishing ground using 3D model implementation.]"

"ABSTRAKPerkembangan penangkapan perikanan tuna seiring dengan perkembangan penggunaan Fish Agregating Divices FADs atau rumpon sebagai alat untuk mengumpulkan sumber daya ikan tuna. Masalah dalam penelitian ini adalah pengunaan rumpon memiliki dampak terhadap kondisi sumber daya ikan, sosial dan ekonomi nelayan. Penelitian ini bertujuan untuk mengkaji pemanfaatan sumber daya ikan tuna dengan menggunakan handline yang berasosiasi dengan rumpon secara berkelanjutan di PPN Palabuhanratu dari aspek biologi sumber daya, sosial dan ekonomi. Penelitian ini menggunakan metode selektivitas, LB-SPR, persepsi masyarakat dan kelayakan usaha penangkapan. Hasilnya menunjukan penggunaan handline selektif terhadap sumber daya ikan cakalang Katsuwonus pelamis , namun tidak selektif terhadap sumber daya ikan madidihang Thunnus albacares dan tuna mata besar Thunnus obesus . Nilai Spawning Potential Ratio SPR atau potensi rasio pemijahan sumber daya ikan cakalang berada diantara limit reference point 20 dan target reference point 40 yang berarti dalam kondisi fully-exploited, sedangkan sumber daya madidihang dan tuna mata besar berada dibawah 20 yaitu dalam kondisi over-exploited. Hasil analisis sosial menunjukkan bahwa penggunaan rumpon bagi nelayan handline di PPN Palabuhanratu tidak menimbulkan adanya konflik pemanfaatan. Terdapat peluang diberlakukannya kebijakan karena nelayan memahami adanya peraturan rumpon dan bersedia mentaati kebijakan yang akan diberlakukan. Hasil analisis kelayakan usaha penangkapan sumber daya ikan tuna dengan handline dikategorikan menguntungkan dan dapat dilanjutkan. Berdasarkan kondisi sumber daya ikan, sosial dan ekonomi nelayan penangkapan sumber daya ikan tuna dengan menggunakan handline di sekitar rumpon dapat dilanjutkan. Kebijakan pemanfaatan rumpon secara berkelanjutan yang direkomendasikan adalah dengan memperbaiki ijin pemasangan rumpon, zonasi daerah penangkapan, pembagian kewenangan, pemberdayaan komunitas masyarakat dan pengaturan operasi penangkapan.

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ABSTRACTTuna fishery development is in line with the use of Fish Aggregating Devices FADs as a tool to gather tuna resources. The problem in this research is that the use of FADs has an impact on fish resources, as well as social problem and fisher rsquo s economic condition. This study will examine the utilization of tuna resources by handline fishers that associated with FADs in PPN Palabuhanratu in terms of fish resources, social and economic aspects using several approaches i.e. selectivity, LB SPR, public perception and feasibility of fishing effort. The results show that handline is selective on skipjack tuna Katsuwonus pelamis , but not on yellowfin tuna Thunnus albacares and bigeye tuna Thunnus obesus . The Spawning Potential Ratio SPR of skipjack fish is in between the limit reference point 20 and the target reference point 40 , which means this fish resources is in fully exploited condition, while yellowfin and big eye tuna have reached overfishing condition below 20 . The use of FADs for the handline fishery in PPN Palabuhanratu does not cause any conflict. There is an opportunity for policy enforcement because the fishers are understands the existence of the FADs regulation and willing to obey the policy. Results on feasibility analysis show that handline tuna fishery in Palabuhanratu is still profitable and can be continued. Based on the condition of fish resources, social and economic fishers, catching tuna using handline around FADs are in sustainable level. This paper recommends the policy of sustainable use of FADs by improving the installation permit of FADs, zoning of fishing grounds, divide management authority, community empowerment and arrange of fishing operations."

"Ikan tongkol abu (Thunnus tonggol) merupakan salah satu spesies ikan pelagis penting yang banyak ditemukan di perairan Indo-Pasifik, hidup di daerah neritik, sehingga dikhawatirkan rentan terhadap overfishing. Oleh sebab itu perlu dilakukan eksplorasi faktor-faktor yang berkaitan dengan aspek reproduksi, morfometri dan makanan sebagai langkah awal untuk mendapatkan data yang nantinya dapat dijadikan dasar dalam pengelolaan berkelanjutan. Penelitian ini bertujuan untuk mengetahui kondisi ikan tongkol abu (Thunnus tonggol) yang ditangkap di Laut Jawa (morfometrik : panjang, berat, ukuran pertama kali tertangkap), reproduksi (perkembangan gonad dan fekunditas) serta jenis makanan. Contoh ikan diperoleh dari ikan yang didaratkan di Pangkalan Pendaratan Ikan Karangsong Indramayu pada bulan April-Mei 2012 sebanyak 164 ekor, ditangkap menggunakan gillnet dengan ukuran mata jaring 4 inchi dan kapal dengan ukuran 30-70 GT yang beroperasi di sekitar Laut Jawa. Ikan diukur panjang dan beratnya, dibedah untuk menentukan morfometri (panjang dan berat), reproduksi (Perkembangan gonad dan fekunditas) dan makanannya. Hasil perhitungan panjang berat ikan tongkol abu (Thunnus tonggol) bersifat alometrik negatif. Nisbah kelamin menunjukkan bahwa antara ikan tongkol abu betina dengan ikan tongkol abu jantan sama banyaknya dengan perbandingan 1:1,34. Tingkat Kematangan Gonad, pada bulan April 2012 ikan sedang mengalami TKG I, II, III dan IV sedangkan pada bulan Mei 2012 ikan yang tertangkap sebagian besar sedang mengalami TKG IV dan ada beberapa yang telah mengalami pemijahan (spent). Fekunditas telur ikan tongkol abu berkisar antara 252.000- 4.138.285 butir. Panjang pertama kali tertangkap 47,6 cm sedangkan ikan yang pertama kali bertelur pada panjang 42,5 cm. Isi lambung ikan tongkol abu yang diteliti adalah ikan teri, karena tergolong predator.

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Longtail tuna (Thunnus tonggol) is one of the important pelagic fish species that are found in the Indo-Pacific waters, living in the neritic habitats, so feared vulnerable to overfishing. It is necessary to explore importants biological factors supporting the sustainable fisheries management of longtail tuna (Thunnus tonggol) population from Java Sea. The objective of this research is to study the reproductive biology, morfomethry and food of longtail tuna (Thunnus tonggol) from Java Sea. A total of 164 samples were taken from fish captured in Java Sea and landed by fish landing centre Karangsong, Indramayu, West Java at April until May 2012, fishing gear gillnet with 4 inch hole. Fish length and weight were measured, dissected to determine morphometry (length and weight), reproduction (gonad development and fecundity) and food. The results of the calculation of the length weight of lontail tuna (Thunnus tonggol) is negative Allometric. Sex ratio showed between males longtail tuna with females longtail tuna as the ratio of 1:1,34. Longtail tuna in Java Sea had a lenght at first captured (Lc) 47,6 cm but mature stage for 42,5 cm. Food of longtail tuna (Thunnus tonggol) is anchovy becaused this species is predator."

"Tingginya permintaan pasar terhadap ikan cakalang mengakibatkan aktivitas penangkapannya dilakukan secara terus-menerus sepanjang tahun sehingga dapat mengancam kelestariannya. Tujuan penelitian yaitu mengetahui distribusi frekuensi panjang ikan cakalang secara temporal dan menganalisis tingkat selektivitas alat tangkap purse seine pelagis besar di fishing ground Samudera Hindia bagian timur. Data yang digunakan adalah data panjang cagak ikan cakalang selama Januari s/d Desember 2016 yang didaratkan di PPS Nizam Zachman Jakarta. Analisis data frekuensi panjang dilakukan dengan membandingkan sebaran individu ikan dalam bentuk histogram, dan analisis selektivitas dengan metode skoring berdasarkan komposisi hasil tangkapan, persentase hasil tangkapan layak tangkap dan membandingkan nilai Lc dan Lm. Hasil penelitian menunjukkan pada bulan juli sampai oktober distribusi frekuensi panjang cagak cakalang terbanyak pada rentang kelas 40-45 cm dengan panjang rata-rata 43 cm atau diatas nilai Lm (42,9 cmFL). Sedangkan pada bulan november sampai juni distribusi frekuensi panjang cagak cakalang berada pada nilai dibawah nilai Lm. Panjang ikan cakalang pertama kali tertangkap (Lc) diperoleh nilai 40,83 cmFL dibawah nilai pertama kali matang gonad (Lm) sebesar 42,9 cmFL. Hasil tangkapan utama purse seine pelagis besar selama penelitian yaitu ikan cakalang 42,6% dan hasil tangkapan sampingan sebesar 57,4%. Jumlah cakalang layak tangkap sebesar 26%, sehingga berdasarkan analisis selektivitas, selektivitas alat tangkap purse seine pelagis besar di perairan Samudera Hindia bagian timur memiliki selektivitas rendah.

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The high market demand for skipjack tuna has resulted in its catching activities continuously throughout the year so can be threaten its sustainability. The objectives of this research are to know the temporal length frequency distribution of skipjack tuna and to analyze the level of selectivity of large pelagic purse seine in the Eastern Indian Ocean fishing ground. The data used were length data of skipjack tuna wich unloaded during January to December 2016 at Nizam Zachman Jakarta Fishing Port. Length frequency data analysis was done descriptively by comparing the distribution of individual fish in the form of histogram, whereas the selectivity analysis done by scoring method based on the catch composition, the capture catch percentage and compare the Lc and Lm values.

The results of this research showed that in July to October, highest distribution of the length frequency of skipjack tuna was in the 40-45 class range, with average length value was higher than Lm value of 43 cmFL and 42.9 cmFL, respectively. While from November until June, the length frequency distribution value of skipjack tuna was lower the Lm value. The skipjack tuna minimum length of caught (Lc) was lower than its minimum length of gonad mature (Lm) of 40.83 cmFL and 42.9 cmFL, respectively. The major catches of large pelagic purse seine during this research was skipjack tuna as much as 42.6%, and by-catch by 57.4%. The amount of catchable fish is 26%, so based on selectivity analysis, the selectivity of the large pelagic purse seine fishing gear in the waters of the East Indian Ocean has low selectivity."