CHARACTERISTICS OF TUNA, SMALL TUNA AND SKIPJACK (TTS) FISHERY IN KUTARAJA OCEAN FISHING PORT, ACEH

Kutaraja Ocean Fishery Port is the oldest port in Banda Aceh City, Lampulo. Fishery resources are a new potential in the regional economic development of Aceh province. Fish resources that have great potential are from the large pelagic fish groups, including Tuna, Small Tuna and Skipjack (TTS) . Fishery characteristics are used to carry out sustainable fishing. This research was conducted at PPS Kuta Raja, Aceh for one year. Data collection was carried out directly through site surveys and interviews with related fisheries actors. Biological data and capturing aspects were carried out using a stratifield random sampling system by placing enumerators. The results showed that the production of TCT at PPS Kutaraja was dominated by 2 fishing gears, purse seine and hand lines. Based on the results of enumeration in 2020, the estimated total production of tuna skipjack and small tuna at PPS Kuta Raja reaches 11,520 tons. The highest total estimated fish catch is skipjack tuna (Katsuwonus pelamis) (SKJ) 5,802 tons, Bullet tuna (Auxis rochei)(BLT) 2814 tons, Yellow fin (Thunnus albacares) (YFT) 2,452 tons, Krai Tongkol (Auxis thazard) (FRI) 448 tons, and Eastern little tuna (Euthynnus affinis) (KAW) 1,745 tonnes. All of the fish caught were dominated by immature fish. So it is very necessary to evaluate the use of fishing gear or the licensing of FADs. The monthly CPUE distribution pattern is the same, where in August it reaches the highest CPUE and in October it reaches the lowest CPUE value.

Sexual maturation in Atlantic salmon male parr may be triggered both in early spring and late summer under standard farming conditions

Male Atlantic salmon (Salmo salar) display different sexual strategies, maturing either as parr during the freshwater phase (as sneaky spawners), or as post smolts following one or several years at sea. First sexual maturation (puberty) occurs at different times depending on environmental and genetic factors. To improve our knowledge on the timing (age and season) of first sexual maturation in Atlantic salmon male parr, we investigated pubertal activation in second generation farmed salmon from the Norwegian river Figgjo, reared under natural conditions of photoperiod and water temperature. Histological analysis, in combination with morphometric measurements, plasma androgen levels and pituitary gonadotropin gene expression analysis revealed that, as previously reported, some male parr initiated early sexual maturation in spring at one year of age. Interestingly, some male parr were observed to initiate sexual maturation already in autumn, six months after hatching (under-yearlings), much earlier than reported in previous studies. One-year old maturing males showed a low induction in gonadotropin levels, while under-yearling maturing males displayed a significant increase in fshb transcripts as compared to immature fish. Plasma testosterone, detectable also in immature males, increased constantly during testes development, while 11-ketotestosterone, undetectable in immature and early maturing males, increased during more advanced stages of maturation. A mild feminization of the testes (ovotestes) was detected in a subset of samples. This study brings new knowledge on the little investigated field of sexually maturing under-yearlings in Atlantic salmon. This is also the first study comparing the physiology of under-yearling vs one-year old maturing male parr, thus bringing new insights to the remarkable plasticity of Atlantic salmon puberty.

KARAKTERISTIK PERIKANAN PUKAT CINCIN PELAGIS BESAR DI PERAIRAN SAMUDRA HINDIA (WPPNRI 572 DAN 573)

Pukat cincin merupakan salah satu jenis alat penangkapan ikan yang digunakan oleh nelayan di Indonesia untuk menangkap ikan pelagis termasuk tuna dan cakalang. Cakalang dan madidihang/tuna sirip kuning merupakan komoditas perikanan penting di Indonesia untuk kebutuhan pasar domistik dan ekspor. Penelitian ini bertujuan untuk mengetahui karakteristik alat tangkap pukat cincin pelagis besar terutama yang menangkap cakalang dan madidihang di perairan WPPNRI 572 dan 573 (Samudra Hindia). Pengumpulan data dilakukan selama tiga tahun dari 2016-2018 di 18 pelabuhan perikanan yang armadanya melakukan aktivitas penangkapan di perairan WPPNRI 572 dan 573. Indikasi proporsi ikan yang sudah dan belum matang gonad dihitung dengan membandingkan ukuran ikan dengan ukuran pertama kali matang gonad (Lm). Hasil penelitian menunjukkan bahwa alat tangkap pukat cincin sangat dominan dalam mengeksploitasi sumber daya cakalang dan madidihang dengan proporsi mencapai 95% di WPPNRI 572 dan 66% di WPPNRI 573. Kebanyakan ikan yang tertangkap didominasi oleh ikan yang belum matang gonad dengan proporsi sebesar 67% untuk cakalang dan 94% untuk madidihang. Hasil analisis menunjukkan bahwa pukat cincin tidak termasuk alat yang selektif untuk menangkap ikan madidihang. Selanjutnya untuk target ikan cakalang, ukuran mata jaring harus diperbesar untuk mencegah tertangkapnya ikan yang belum matang gonad.Purse seine is one of dominant fishing gear used to catch pelagic species include skipjack and yellowfin tuna, two commercial species in Indonesia’s marine waters. This research aimed to analyze characteristic of purse seine fishery focusing on skipjack and yellowfin tuna within FMA 572 and 573. All the catch-effort data was collected from 18 fishing ports during the period of 2016-2018. All the vessels (purse seiners) were known to be actively fished within FMA 572 and 573. Proportion of mature and immature fish were calculated by comparing the fish length with its length at first maturity (Lm). The results showed that purse seine was a significantly gear to catch skipjack tuna and yellowfin tuna with proportion of 95% in FMA 572, and 66% in FMA 573, respectively. Most of the catch were dominated by immature fish with proportion of 67% for skipjack tuna and 94% for yellowfin tuna. The study concluded that purse seine is not recommended to exploit yellowfin tuna. Futhermore for targeting skipjack tuna, mesh-size of the net need to be in creased, allowing immature fish to escape from the gear that maintain sustainability.

PENENTUAN UKURAN PERTAMA KALI MATANG GONAD (Lm) CAKALANG (Katsuwonus pelamis Linnaeus, 1758) DI SAMUDRA HINDIA SELATAN BALI

Cakalang tergolong kelompok jenis ikan pelagis besar yang keberadaanya cukup melimpah di perairan Samudera Hindia termasuk perairan selatan Bali. Informasi biologi reproduksi sangat penting terutama untuk mengetahui kapan ikan tersebut memijah sehingga dapat digunakan sebagai dasar pengelolaannya. Cakalang memijah beberapa kali (multiple spawner), hal ini diketahui berdasarkan tingkat perkembangan oosit yang lebih dari satu tingkatan dalam satu gonad aktif. Sampel gonad cakalang betina diperoleh dari Pangkalan Pendaratan Ikan Kedonganan, Bali. Sebanyak 106 ekor cakalang betina dengan kisaran panjang cagak 37-71 cmFL dan kisaran bobot 902-7.214 gram yang teramati. Sampel gonad dalam keadaan segar langsung difiksasi menggunakan larutan buffer-formalin 10% kemudian dianalisis secara histologis menggunakan metode parafin dan pewarnaan HE (Harris-Haemotoxilin dan Eosin). Cakalang betina yang diklasifikasikan sebagai ikan yang belum dewasa (immature) memiliki karakteristik oosit unyolked (UY) yang lebih gelap pewarnaannya, memiliki diameter <156 µm dan Early yolked (EY) yang memiliki diameter 114-249 µm. Cakalang dewasa (mature) memiliki karakteristik perkembangan ovari berupa adanya oosit pada tingkat yang lebih tinggi yaitu advanced yolked (AY) dengan diameter oosit berkisar antara 180-448 µm, migratory nucleus (MN) 239-468 µm dan hydrated (Hy) dimana ukuran oositnya sangat besar yaitu sekitar 459-552 µm dan berbentuk seperti noda merah muda (pink stain). Cakalang betina di perairan Samudera Hindia selatan Bali memiliki perkembangan oosit yang asynchronous (tidak seragam) yang ditandai oleh munculnya beberapa tingkat perkembangan oosit dalam satu ovari. Ukuran panjang pertama kali matang gonad (Lm) cakalang betina yaitu 44,7 cmFL. Cakalang betina dewasa yang berstatus memijah aktif (actively spawning) ditemukan di setiap bulan pengamatan (April-September) dan diduga memijah sepanjang tahun. Skipjack tuna is classified as a large pelagic fish species and has abundant presence in the waters of the Indian Ocean including the waters of southern Bali. Information related to reproductive biology is very important especially to find out when the fish spawn so that they can be used as a basis for its management. Skipjack spawns several times (multiple spawner), this is known based on the level of oocyte development that was more than one level in one active gonad. Samples of female skipjack gonads were obtained from Kedonganan, Bali. A total of 106 female skipjack tuna with length range of 37-71 cmFL and weight range of 902-7,214 grams were observed. Gonad samples in fresh condition were immediately fixed using a 10% buffer-formalin solution then histologically analyzed using the paraffin method and HE staining (Harris-Haemotoxilin and Eosin). Female skipjack classified as immature fish has the characteristics of unyolked oocytes (UY) which are darker in coloration, have a diameter <156 ìm and Early yolked (EY) which has a diameter of 114-249 ìm. Adult skipjack (mature) has the characteristics of ovarian development in the form of oocytes at a higher level, namely advanced yolked (AY) with oocyte diameter ranging from 180-448 µm, migratory nucleus (MN) 239-468 µm and hydrated (Hy) where oocyte size is very large, which is around 459-552 µm and shaped like a pink stain. Female skipjack in the waters of the Indian Ocean south of Bali has an asynchronous (non-uniform) oocyte development which is characterized by the appearance of several levels of oocyte development in one ovary. Size at first maturity (Lm) of female skipjack in Indian Ocean southern Bali was 44.7 cmFL. Adult skipjack females with active spawning status are found every month of observation (April-September) and suspected to spawn throughout the year.

Regulating and Understanding Victorian Fisheries

This chapter investigates local fisheries and fish species in Victoria. The ASV’s fisheries regulation policies and fisheries management program are outlined to create an understanding of the commercial potential of Australian fisheries and the protection of fishes. The analysis of fishery management illustrates the actions of local fishermen and the damages done to them during and after the gold rush. The investigation of commercial fishery provides insight on the Murray Darling river system, the labouring of the Yorta Yorta people, and Chinese merchants and fishermen. Local fishermen argued that their Chinese competitors used nets with a very fine mesh, destroying immature fish that they thought unfit for market. This practice would bring Chinese fishermen into conflict with the ASV and the colonial government’s fish protection policies as they developed in the mid-1860s. Also discussed are the controversies over taxonomic relationships among fish species and how declining fish stocks initiated protective regulation. Overall, the chapter illustrates how the ASV attempted to restore and improve Victorian fisheries.

Bioenergetic and limnological foundations for using degree-days derived from air temperatures to describe fish growth

Degree-days (DD) are an effective metric for quantifying the thermal opportunity for ectotherm growth. There is strong empirical evidence to suggest that DD are useful for describing fish growth and that immature growth increases linearly with DD. However, fish ecology lags behind other disciplines in the widespread adoption of DD. We provide (1) a foundation for the observed linear relationship between immature fish growth and DD and (2) justification for using DD derived from air temperatures as a proxy for DD derived from water temperatures in fish science. We use bioenergetics models and both simulated and empirical water temperatures to show that immature annual and interannual fish growth are approximately linear with water DD. We then use simulated and empirical data to show that air and surface water temperatures are often highly correlated and that immature fish growth is also approximately linear with air DD. By connecting the dots among air temperature, water temperature, and fish growth, we lay the foundation for wider adoption of DD in fish science.

Morphometric Aspects of Scad Decapterus macrosoma Bleeker, 1851 in Cape of Salonggar Regency

This study aims to determine the biological appearance of globe fish that includes size distribution, growth pattern, sex ratio and maturity level of gonad (TKG) in Tanjung Salonggar Melonguane waters of Talaud Islands Regency. Sampling was conducted from May to July 2017. Decapterus macrosoma has found during the study were 268 with total size of 150 - 244 mm and the weight ranged from 34 to 142 grams. Kite fish caught in Tanjung Salonggar has a negative allometric growth type that is the length increase faster than weight gain (b <3). The sex ratio of male fish and female fish is equal to 1: 1, with maturity level of Gonad (TKG) I up to TKG V. The highest gonadal maturity level is found in June and July, both male and female fish, while in May fish which is caught predominantly by an immature fish gonad. Keywords: Biological appearance, Decapterus macrosoma, growth pattern.AbstrakPenelitian ini bertujuan untuk mengetahui tampilan biologis ikan layang yang meliputi sebaran ukuran, pola pertumbuhan, rasio kelamin dan tingkat kematangan gonad (TKG) di Perairan Tanjung Salonggar Melonguane Kabupaten Kepulauan Talaud. Pengambilan sampel dilakukan pada bulan Mei sampai bulan Juli 2017. Ikan layang Decapterus macrosoma yang diperoleh selama penelitian sebanyak 268 ekor dengan Sebaran ukuran panjang total 150 – 244 mm dan berat berkisar 34 – 142 gram. Ikan layang yang tertangkap di Tanjung Salonggar memiliki tipe pertumbuhan allometrik negatif yaitu pertambahan panjang lebih cepat dari pertambahan berat (b < 3). Rasio kelamin ikan jantan dan ikan betina adalah seimbang yaitu 1 : 1, dengan Tingkat Kematangan Gonad (TKG ) I sampai dengan TKG V. Tingkat kematangan gonad tertinggi ditemukan pada bulan Juni dan Juli, baik ikan jantan maupun ikan betina, sementara pada bulan Mei ikan yang tertangkap didominasi oleh ikan yang belum matang gonad.Kata kunci : Tampilan biologis, Decapterus macrosoma, Pola pertumbuhan.

Potential of sustainable and biological aspect of sting ray (Dasyatis sp.) as catch fisheries status overview in Java Sea

Stingray fish is a demersal fish commodity in Indonesian waters which decreasing in catch. The purpose of this research is to know the potential of sustainable and some aspects of Stingray fish biology by using the Maximum Sustainable Yield (MSY) indicator as the fishing status in Java Sea. Data of catch and effort taken from production data of year 2006-2015 and primary data to know some aspect of biology is taken at TPI port of Cirebon and Tegal Specification data of fish catching tools Pari obtained from fisherman interview. The data of the catch in the analysis using Surplus Production Method (Schaefer) and observed aspects of stingray biology include: sex ratio and distribution of length of Stingray fish. The results showed the MSY value of Stingray fish was 894.275 tons / year and fMSY value of 34.716 ships / year. The sex ratio of male Stingray fish with female Stingray fish is still balanced, which is 1: 1.34 and the size of long frequency entered into the category of immature fish gonad and fish which first ripe gonad, which ranges between length 16-22 cm both male fish or female. Based on the research results can be concluded that Stingray fish catchment in Java sea still in sustainable condition.

Komposisi dan distribusi hasil tangkapan kapal pukat cincin KM Grasia 04 di perairan Laut Maluku (Composition and distribution catch of Grasia 04 purse seiner in Molucca Sea waters)

Purse seine is considered to be the most productive fising gear to catch pelagic fish, so there are many purse seiners that based in Bitung Oceanic Fishing Port operate in Fisheries Management Area of the Republic of Indonesia (WPP) 715 Moluccas Sea. There was and issue that the catches of purse seiner around FADs was classified as immature fish. Therefore, necessary to study the diversity and distribution of purse seiner catches in the area. The data collection was done by direct observation and active participation in the field and deep interviews with the crews of Grasia 04 purse seiner. At each hauling, twenty fish from each species were taken randomly measured their fork lengths. Catches during the study consisted of six species; namely skipjack (Katsuwonus pelamis), yellow fin tuna (Thunnus albacores), little tuna (Auxis thazard), scad mackerel (Decapteru smacarellus), rainbow runner (Elagatis bipinnulata), oceanic trigger fish (Canthidermis maculata) and trevally (Selaroides leptolepis). The dominatcatch in each hauling were skipjack, yellowfin, tuna and scad mackerel. Results were showed that most of the catches of Grasia 04 purse seinerin the waters of Moluccas Sea not legal size.Keywords: Composition and distribution catch, purse seiner Grasia 04, Molucca Sea. ABSTRAKAlat tangkap purse seine dianggap paling produktif untuk menangkap ikan pelagis, sehingga banyak kapal purse seine yang berpangkalan di Pelabuhan Perikanan Samudera Bitung beroperasi di Wilayah Pengelolaan Perikanan RI (WPP) 715 Laut Maluku. Beberapa issue menyebutkan bahwa hasil tangkapan purse seine terutama di sekitar rumpon tergolong ikan-ikan yang belum dewasa. Oleh karena itu, perlu mempelajari keragaman dan distribusi hasil tangkapan purse seine di wilaya tersebut. Pengumpulam data dilakukan dengan cara pengamatan langsung dan partisifasi aktif dilapangan, wawancara dengan anak buah kapal KM Grasia 04. Pada setiap kali hauling, diambil secara acak 20 ekor ikan sampel setiap jenis dan mengukur panjang bakunya. Hasil tangkapan selama penelitian adalah 6 jenis ikan; yaitu ikan cakalang (Katsuwonuspelamis), madidihang (Thunnusalbacores), tongkol (Auxis thazard), malalugis (Decapterus macarellus), sunglir (Elagatis bipinnulata), tato batang (Canthidermis maculata) dan selar (Selaroides leptolepis).Tetapi hasil tangkapan yang dominan pada setiap hauling adalah cakalang, madidihang, tongkol dan malalugis. Hasil analisis menunjukan bahwa sebagian besar hasil tangkapan kapal purse seine Grasia 04 di perairan Laut Maluku belum layak tangkap.Kata kunci: Komposisi dan distribusi tangkapan, pukat cincin KM Grasia 04, Laut Maluku

THE EFFECT OF ATTRACTOR MATERIAL ON PELAGIC FISH CAPTURED USING PAYANG BUGIS IN PASAURAN WATERS, PROVINCE OF BANTEN

Rumpon (fish aggregating device) as an auxiliary gear operated in Pasauran waters, Sunda Strait was longer and more widely used in Indonesia to catch pelagic fish. The characteristic speciescomposition, size, and gonado somato index (GSI) pelagic fish around 3 kinds of rumpon attractor materials, i.e. Cocos nucifera, Nypa fructican, and Areca catechu leaves will determine the effects of attractor materials will affect the sustainability of pelagic fish associated. Identification and composition length, weight and gonado somato index pelagic fish were identified in this research with different attractor material in all seasons. Experimental fishing carried out by using payang Bugis. The result show that the Cocos nucifera leaves are the best attractor material based on the number of fish species and durability in all seasons. Further, the gonado somato index of small pelagic fish were caught around rumpon are gonado somato index I 4%, gonado somato index II 33%, gonado somato index III 35%, gonado somato index IV 25%, and gonado somato index V 3%. Pelagic fish around attractor materials have gonado somato index I-III 72%. This result indicated that the small pelagic fish caught around rumpon are immature fish.