Albacore (Thunnus alalunga) is the third dominant catch of Indonesian tuna longline fishery operating in the eastern Indian Ocean. The percentage production of albacore catch was reaching up 6% of the total catch of tuna groups in Indonesia. Thi study aims to examine a relative abundance indices using standardized catch per unit of effort (CPUE) of longliner based on albacore tuna. This information will give a valuable input and information to support stock assessment particularly in the regional basis. In this study, we use Generalized Linear Model (GLM) with Tweedie distribution to standardize the CPUE and to estimate relative abundance indices based on the Indonesian longline dataset time series. Data were collected from January 2006 to October 2015 (106 trip observer and 8.989 fishing days) by conducting direct onboard observation on tuna longline vessels operating in the Indian Ocean. The result show that year, area,hooks between floats, year*season, year*area and year* hooks between floats significantly influenced the nominal CPUE of albacore. The highest value of Standardized CPUE appeared in 2014 and probably related to the large number of foreign fishing vessels with a high capacity (over 60 GT) targeting frozen tuna including albacore. In 2015, standardized CPUE value was sharply decreased due to the ban of foreign vessels in Indonesia.

<p>Tuna longline atau rawai tuna merupakan salah satu alat tangkap yang sangat efektif untuk menangkap tuna. Selain efektif alat tangkap ini juga merupakan alat tangkap yang selektif terhadap hasil tangkapannya. Namun demikian, alat tangkap ini masih menimbulkan suatu masalah dimana ikan hasil tangkapan yang diperoleh tidak semuanya merupakan hasil tangkapan utama (target species), ada sebagian yang merupakan hasil tangkapan sampingan (by-catch). Sebagian besar hasil tangkapan sampingan tuna longline memiliki nilai ekonomis, hanya jenis pari lumpur dan ikan naga yang tidak memiliki nilai ekonomis. Namun demikian, justru yang tidak memiliki nilai ekonomis mendominasi hasil tangkapan sampingan pada perikanan tuna longline. Oleh karena itu perlu adanya tindak lanjut dengan menyusun peraturan atau regulasi yang terkait dengan pengelolaan ikan hasil tangkapan sampingan dan pengelolaan yang benar terhadap hasil tangkapan tersebut beserta habitatnya agar terjaga kelestarian sumberdayanya dan juga tetap menjadi sumber pendapatan masyarakat.Tulisan ini membahas secara ringkas tentang isu hasil tangkapan sampingan pada perikanan tuna longline, komposisi jenisnya, pemanfaatannya dan kebijakannya.</p><p>Tuna longline is one of the most effective fishing gears to catch tuna. In addition, this fishing gear is selective to catch tuna. However, this gear is still causing a problem where some species other than their target species were caught as by-catch. Most of by-catch species from the tuna longliners have an economic value, except pelagic stingrays and lancetfish. In fact, these by-catch species (non economical-valued species) dominated the longline catch. Therefore, it is needed to develop rules or regulations related to the management of the fish by-products, and properly manage the fishing activities on these by-catch species and habitat preservation to preserve its resources and also remain as a source of income. This paper briefly discusses the issue of by-catch in tuna longline fisheries, species composition, its utilization and its policy.</p>

Tuna sirip kuning (Thunnus albacares) merupakan hasil tangkapan terbanyak dibandingkan dengan jenis tuna lainnya di Indonesia. Ketersediaan stok tuna sirip kuning di Samudra Hindia, pada saat ini, diperkirakan dalam keadaan lebih tangkap. Oleh karena itu, pengelolaan secara tepat dan bertanggungjawab penting dilakukan untuk melindungi spesies tuna, salah satu caranya dengan mengkaji alat tangkap yang digunakan. Tulisan ini bertujuan untuk mengungkapkan produktivitas dan hasil tangkapan armada tonda, serta struktur ukuran dan hubungan panjang bobot ikan tuna sirip kuning yang di daratkan di selatan Jawa. Komposisi tangkapan tertinggi dari armada tonda diseluruh pendaratan ikan tuna di selatan Jawa terdiri atas tuna sirip kuning dan cakalang. Analisis CPUE menunjukkan hasil yang fluktuatif di setiap lokasi pendaratan tuna sirip kuning di Selatan Jawa. Tuna sirip kuning yang tertangkap di selatan Jawa dengan armada tonda sebagian besar adalah ikan yang belum layak tangkap karena berukuran kurang dari 100 cmFL. Struktur ukuran panjang tuna sirip kuning yang tertangkap semakin ke Timur semakin panjang ukurannya. Pola pertumbuhan tuna sirip kuning yang tertangkap di Binuangeun memiliki pola isometrik, PPN Palabuhanratu bersifat allometrik Positif, PPP Sadeng, P2SKP Pacitan, PPN Prigi dan P2SKP Sendang Biru bersifat allometrik negatif. Yellowfin tuna (Thunnus albacares) is the largest catch compared to other tuna species in Indonesia. The availability of yellowfin tuna stock in the Indian Ocean, at present, is estimated to be in overfished condition. Therefore, proper and responsible management is important to protect the species. One of the ways is by studying the used fishing gear. This paper aims at determining vessel’s productivity, as well as composition, size structure and length-weight relationship of yellowfin tuna catches from troll line fleet in the Indian Ocean part of south Java. The highest catch of tuna in all of the troll line landing places was yellowfin tuna, following by skipjack tuna. CPUE analysis showed fluctuating results at each landing site. Yellowfin tuna sizes caught by troll line fleet were mostly less than 100 cmFL and categorized as should not be properly caught. Geographically, getting to the east the average size of the catches tend to be larger. The growth pattern of yellowfin tuna catches landed in Binuangeun was isometric; Palabuhanratu was positive allometric; while those landed in Sadeng, Pacitan, Prigi and Sendang Biru were negative allometric.

ABSTRAK Produksi ikan Madidihang yang cenderung menurun yang disebabkan oleh penangkapan yang berlebih dikhawatirkan dapat mengganggu kelestarian sumberdaya ikan Madidihang. Oleh sebab itu perlu adanya penelitian tentang hasil tangkapan ikan Madidihang. Hasil yang didapatkan dari penelitian diharapkan dapat memberi gambaran tentang kondisi ikan Madidihang di Samudera Hindia. Penelitian dilakukan pada bulan April-Mei 2016 di Pelabuhan Benoa. Penelitian ini bertujuan untuk mengetahui kondisi ikan madidihang melalui telaah panjang-bobot, faktor kondisi, ukuran pertama kali tertangkap, panjang asimtotik (L∞) ikan Madidihang di Samudera Hindia berdasarkan hasil tangkapan yang didaratkan di Pelabuhan Benoa, Bali. Metode yang digunakan yaitu metode survei. Pengolahan data menggunakan perangkat lunak microsoft excel. Hasil penelitian menunjukkan ukuran ikan Madidihang bulan April-Mei 2016 berkisar 70 – 178 dengan modus 112 cmFL. Persamaan hubungan panjang-bobot didapatkan W = 0,00002*FL2,966 dengan pola pertumbuhan isometrik. Faktor kondisi yang didapatkan antara 1,64 – 2,44, dan ukuran ikan pertama kali tertangkap 133 cmFL. Panjang asimtotik (L∞) = 190,05 cmFL. Berdasarkan ukuran ikan yang tertangkap dimana Lc > ½ L∞ dapat dinyatakan bahwa ukuran yang tertangkap telah layak tangkap. Kata Kunci : Ikan madidihang; hubungan panjang-bobot, faktor kondisi, ukuran pertama kali tertangkap ABSTRACT Yellowfin tuna production tends to decrease due to excess catching that is feared could interfere with the preservation of resources yellowfin tuna. Hence, it is necessary to do this research Catch Product of Yellowfin Tuna. Results obtained from the study are expected to give an idea of yellowfin condition in the Indian Ocean. This research was conducted in April-May 2016 at the Benoa Port. The aimed of this research was to determine condition of yellowfin tuna through the study of the length-weight relationship,condition factor, length at first capture, and asymptotic length (L∞) of yellowfin tuna in the Indian Ocean based on catches landed at the port of Benoa, Bali. This research used survey method. Data processing used the software of Microsoft Excel and FISAT II. The results have shown the size of the yellowfin tuna from April-May 2016 ranging from 70 – 178 with 112 cmFL. The equation of length weights correlation was obtained W = 0.00002*FL2,966 with isometric growth pattern. The condition factor obtained was between 1.64 to 2.44, and the size of the first caught fish is 133 cmFL. Asymptotic length (L∞) = 190.05 cmFL. Based on the size of fish caught where Lc > ½ L∞ can be stated that the size of which was caught had a decent catch.  Keywords: Yellowfin Tuna; length-weight relationship; condition factor, length at first capture

Indonesia has the largest chondrichthyan fishery in the world, with a reported of 105,000 and 118,000 tonnes landed in 2002 and 2003 respectively. Scalloped hammerhead shark was either targeted or by-catch from this fishery, mostly for its fins. Despite of the growing concern around the world, the availability of biological data of this species, especially in the Eastern Indian Ocean is still lacking. The objectives of this paper are to present some biological information (size composition and sex ratio) of the scalloped hammerhead, from coastal fisheries in Eastern Indian Ocean. The data used for the analysis comprised of two components, i.e. survey data in 2010 (February, March, June, August, October and December) and data from daily monitoring shark landing in 2013 (January to December). Substantially lower mean size, more immature sharks and more frequent of female caught over years showed that scalloped hammerhead shark in the Eastern Indian Ocean are facing intensive fishing pressure which could lead to overfishing. This could harm the sustainability of scalloped hammerhead shark resource in the long run. The relationship between clasper length and total length was positively correlated where every 5 cmTL increment on clasper length adding 51 cmTL on total length.