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.
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.
<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>
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
Ikan cakalang (Katsuwonus pelamis Linnaeus, 1758) yang tersebar luas di Samudra Hindia selatan Jawa, Bali dan Nusa Tenggara telah dieksploitasi secara terus menerus dengan berbagai alat tangkap. Pengelolaannya saat ini belum rasional karena masih diasumsikan sebagai unit stok tunggal tanpa adanya bukti ilmiah sehingga rentan mengalami lebih tangkap. Penelitian ini bertujuan untuk mengindentifikasi struktur stok ikan cakalang dengan teknik analisis bentuk otolith. Sampel otolith (saggittae) dikumpulkan pada bulan April, Agustus, dan September tahun 2016 di 4 lokasi, yaitu: Binuangeun, Sadeng, Prigi, dan Labuhan Lombok. Rekonstruksi bentuk otolith dilakukan dengan pendekatan outline analysis menggunakan teknik transformasi discrete wavelet. Uji statistik multivariate dengan kluster analisis menggunakan canonical analysis ofprincipal (CAP) dan uji ANOVA-like permutation juga diterapkan untuk menentukan signifikansi antar populasi. Hasil penelitian menunjukkan bahwa analisis bentuk otolith dapat digunakan sebagai penanda yang akurat untuk mengidentifikasi struktur stok. Bentuk otolith ikan cakalang bervariasi khususnya pada bagian rostrum, namun tidak berbeda nyata antar populasi (p>0,001). Hal tersebut berarti struktur stok ikan cakalang di Samudra Hindia (WPP NRI573) terdiri dari 1 populasi yang bergerak mengikuti pola perubahan lingkungan perairan di sepanjang Samudra Hindia. Skipjack tuna (Katsuwonus pelamis Linnaeus, 1758) distributed vastly along the Indian Ocean south of Java, Bali and Nusa Tenggara. It has been exploited by various fishing gear yet it always assumed to be a single stock. It was not based on scientific evidence but merely based on “a scientific assumption”, so that vulnerable to subject of overfishing. This research aims to examine the alternative tool for identifying the stock structure based on the otolith shape. Sampling location took place in four regions, namely: Binuangen, Sadeng, Prigi and Labuhan Lombok. The otolith (sagittae) samples was collected during April, August, and September 2016. The otolith shape was reconstructed using outline analysis with discrete wavelet transformation technique. A multivariate statistic using canonical analysis of principal (CAP) and ANOVA-like permutation test were also used to determine the signification among populations. The result showed that skipjack’s otolith shape was varied from one and another, especially in the rostrum. But it was not statistically different among regions (p>0.001), which means a single stock for skipjack in the Indian Ocean (Indonesian territory of FMA 573). This study also proved that otolith shape can be useful marker tool to identify stock structure for management purpose.
Yellowfin (Thunnus albacares) and bigeye (T. obesus) tuna have been intensively exploited by longline fleets since 1980's, however, a large proportion of zero catch per set of target species still accurred. Zero catch data contributed significantly to the low catch per unit of effort (CPUE) compared to other countries at the same fishing area. Therefore, understanding the factors contributed to the CPUE of tuna is essential, in order to improve longline fishing efficiency. A total of 2.115 set-by-set data were obtained from Indonesian Scientific Observer Program. The onboard observations were carried out at commercial tuna longline operated in Eastern Indian Ocean from August 2005 to December 2014. Several analytical approaches were conducted in this paper. First, General Linear Model (GLM) was applied in order to model the relationship between CPUE with all the variables involved. Second, boxplot diagram, polynomial and linear regression were applied to fit the relationship between CPUE with set time, soak time and depth (represented by hook position) respectively. The result showed that, there was no significant relationship between set time and CPUE of bigeye and yellowfin tuna. Soak time was positively related with CPUE of yellowfin and affect adversely on bigeye. Depth also have significant relationship with CPUE of tuna, where catch of yellowfin decreased linearly with hook depth, whereas catch of bigeye was performed the opposite. Improvement in tuna longline fishery in eastern Indian Ocean can be achieved through implementation of the specific soak time and hook depth for each target species, i.e. yellowfin and bigeye tuna.
In Indonesia, about 80% of fishing activities are small-scale and play major role both economically and socially. Previous studies mostly concentrated in Java, while in eastern part of Indonesia the information still scarce and limited. The study was conducted from January to December 2013, describes in detail the gears, fleets and catch dynamics of the small-scale tuna fisheries operating based in Labuhan Lombok Coastal Fishing Port (PPP. Labuhan Lombok). Small-scale tuna fishery in Labuhan Lombok are characterized by the small boats less than 10 GT, operating both troll line and hand line simultaneously, targeting large tuna, skipjack tuna and small tuna. Fishing season starts from April to August and influence by southwest monsoon wind and the presence of middleman as the connector between fishers and the market are the main character of the small-scale fisheries business in this area.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.