scholarly journals PENDUGAAN KELIMPAHAN IKAN CAKALANG (Katsuwonus pelamis) SECARA SPASIAL DAN TEMPORAL DI PERAIRAN SELAT MAKASSAR MENGGUNAKAN DATA CITRA SATELIT DAN TEKNIK SISTEM INFORMASI GEOGRAFIS

Author(s):  
Muhammad Ikhsan Amir ◽  
Mukti Zainuddin ◽  
Najamuddin Najamuddin ◽  
Andi Rani Sahni Putri
Keyword(s):  

Penelitian ini bertujuan untuk menghasilkan informasi zona potensial penangkapan ikan serta mengestimasi kelimpahan ikan Cakalang di perairan Selat Makassar berbasis data satelit dan teknik Sistem Informasi Geografis (SIG). Data yang digunakan terdiri dari data primer (titik koordinat penangkapan, suhu permukaan laut, klorofil-a, salinitas, dan jumlah hasil tangkapan) dan data sekunder (citra suhu permukaan laut, klorofil-a, kedalaman, kecepatan arus, dan salinitas). Prediksi kelimpahan ikan cakalang dihitung dengan persamaan multiple regresi kemudian dipetakan dengan teknik sistem informasi georafis. Hasil menunjukkan bahwa zona potensial penangkapan ikan cakalang di perairan selat Makassar pada bulan April – Juli 2018 secara umum berada pada perairan yang lebih dalam. Adapun prediksi kelimpahan ikan cakalang berdasarkan zona potensial penangkapan ikan pada bulan April diperoleh sebanyak 39,6430 ekor/km², pada bulan Mei sebanyak 24,0087 ekor/km², pada bulan Juni sebanyak 18,4314 ekor/km², dan pada bulan Juli sebanyak 8,5404 ekor/km². Kata Kunci: Ikan cakalang, Selat Makassar, kelimpahan, tangkapan

Author(s):  
Gwenaëlle Wain ◽  
Loreleï Guéry ◽  
David Michael Kaplan ◽  
Daniel Gaertner

Abstract Numerous pelagic species are known to associate with floating objects (FOBs), including tropical tunas. Purse seiners use this behaviour to facilitate the capture of tropical tunas by deploying artificial drifting fish aggregating devices (dFADs). One major recent change has been the integration of echosounders in satellite-tracked GPS buoys attached to FOBs, allowing fishers to remotely estimate fishable biomass. Understanding the effects of this new technology on catch of the three main tuna species (yellowfin tuna, Thunnus albacares; bigeye tuna, Thunnus obesus; and skipjack tuna, Katsuwonus pelamis) is important to accurately correct for this change in catch-per-unit-effort (CPUE) indices used for stock assessments. We analysed catch data from the French purse seine fleet for the period 2010–2017 in the Indian Ocean to assess the impact of this fleet’s switch to echosounder buoys around 2012. Results indicate that echosounders do not increase the probability a set will be succesful, but they have a positive effect on catch per set, with catches on average increasing by ≈2−2.5 tonnes per set (≈10%) when made on the vessel's own dFADs equipped with an echosounder buoy. Increases were due to a decrease in sets below ≈25 tonnes and an increase in those greater than ≈25 tonnes, with a non-linear transition around this threshold. This increase explains the considerable investment of purse seiners in echosounder buoys, but also raises concerns about bias in stock size estimates based on CPUE if we do not correct for this fishing efficiency increase.


1999 ◽  
Vol 202 (16) ◽  
pp. 2127-2138 ◽  
Author(s):  
T. Knower ◽  
R.E. Shadwick ◽  
S.L. Katz ◽  
J.B. Graham ◽  
C.S. Wardle

To learn about muscle function in two species of tuna (yellowfin Thunnus albacares and skipjack Katsuwonus pelamis), a series of electromyogram (EMG) electrodes was implanted down the length of the body in the internal red (aerobic) muscle. Additionally, a buckle force transducer was fitted around the deep caudal tendons on the same side of the peduncle as the electrodes. Recordings of muscle activity and caudal tendon forces were made while the fish swam over a range of steady, sustainable cruising speeds in a large water tunnel treadmill. In both species, the onset of red muscle activation proceeds sequentially in a rostro-caudal direction, while the offset (or deactivation) is nearly simultaneous at all sites, so that EMG burst duration decreases towards the tail. Muscle duty cycle at each location remains a constant proportion of the tailbeat period (T), independent of swimming speed, and peak force is registered in the tail tendons just as all ipsilateral muscle deactivates. Mean duty cycles in skipjack are longer than those in yellowfin. In yellowfin red muscle, there is complete segregation of contralateral activity, while in skipjack there is slight overlap. In both species, all internal red muscle on one side is active simultaneously for part of each cycle, lasting 0.18T in yellowfin and 0.11T in skipjack. (Across the distance encompassing the majority of the red muscle mass, 0.35-0.65L, where L is fork length, the duration is 0.25T in both species.) When red muscle activation patterns were compared across a variety of fish species, it became apparent that the EMG patterns grade in a progression that parallels the kinematic spectrum of swimming modes from anguilliform to thunniform. The tuna EMG pattern, underlying the thunniform swimming mode, culminates this progression, exhibiting an activation pattern at the extreme opposite end of the spectrum from the anguilliform mode.


2002 ◽  
Vol 62 (3) ◽  
pp. 453-457 ◽  
Author(s):  
B. M. M. FERNANDES ◽  
A. KOHN ◽  
A. L. SANTOS

Rhipidocotyle pentagonum (Ozaki, 1924) is reported for the first time in South America parasitizing Auxis thazard and in a new host Katsuwonus pelamis. Tergestia laticollis (Rudolphi, 1819) is reported for the first time in South America and in Thunnus albacares, representing a new host record. Copiatestes filiferus (Leuckart, in Sars, 1885) is recorded for the first time in Brazil and in Thunnus albacares, another new host record. Tetrochetus coryphaenae (Yamaguti, 1934) is presented for the first time in Brazil parasitizing Thunnus albacares.


Author(s):  
Colombo Estupiñán-Montaño ◽  
Fabian Pacheco-Triviño ◽  
Luis G. Cedeño-Figueroa ◽  
Felipe Galván-Magaña ◽  
Jose F. Estupiñán-Ortiz

We analysed the stomach contents of 69 silky sharks Carcharhinus falciformis, 44 blacktip sharks Carcharhinus limbatus and 24 whitenose sharks Nasolamia velox caught in the Ecuadorian Pacific from August 2003 to December 2004. Prey included bony fishes, elasmobranchs, molluscs, crustaceans and turtles, with bony fishes being the most important to the diets of all three sharks, suggesting they are piscivorous predators. Based on the index of relative importance, the C. falciformis diet includes Thunnus albacares, Thunnus sp. and Auxis thazard, as well as some squid, fish and turtles. Similarly, the C. limbatus diet was dominated by T. albacares, Exocoetus monocirrhus, A. thazard, Katsuwonus pelamis, members of the Ophichthidae family and other elasmobranchs. Meanwhile, N. velox consumed mainly Dosidicus gigas, Larimus argenteus, Cynoscion sp. and Lophiodes spilurus. There is little competition for food between these tertiary carnivores: C. limbatus prefers prey from coastal-oceanic habitats; C. falciformis consumes mostly oceanic prey and N. velox focuses on prey from coastal habitats. The lack of information on the biology of sharks in Ecuador hinders the development of appropriate management and conservation plans to protect shark resources. This study increases our knowledge and understanding of sharks in Ecuador, thus contributing to their conservation.


2018 ◽  
Vol 5 (2) ◽  
pp. 44
Author(s):  
Desi Arisanti

the current utilization of nike fish and tuna is still limited to fresh condition. Crackers are a very popular food by all levels of society. Utilization of nike fish and tuna in processed form with longer shelf life has not been done. Nutritional content of both types of fish is a reason in the selection as a basic ingredient in making crackers. The purpose of this research is to know the formulation of nike fish and tuna to the quality of crackers. The observation parameters in this study are the level of favorite or hedonic method, water content, ash content, bloom and texture analizer. The results showed that the average water content of nike fish crackers and skipjack fish from treatment A1 3.3%, treatment A2 3.29%, A3 3.77%. Mean of ash content at treatment of A1 1,97%, treatment of A2 1,55%, treatment of A3 1,58%. The average of A1 is 283,54%, A2 242,75%, A3 182,23%. and the mean of analyzer analyzer test at A1 1185,6%, A2 708,9%, and A3 783,83%. Based on the results and the discussion that has been done on the quality of crackers, it can be concluded that the best formula and liked by the panelists is formula A1


2017 ◽  
Vol 14 (3) ◽  
pp. 313 ◽  
Author(s):  
Budi Nugraha ◽  
Enjah Rahmat

Tulisan ini menyajikan tentang status perikanan huhate di Bitung meliputi deskripsi unit penangkapan, daerah penangkapan, komposisi hasil tangkapan, catch per unit of effort, dan ukuran ikan pertama kali tertangkap. Data dikumpulkan selama tahun 2004 sampai dengan 2005. Hasil penelitian menunjukkan bahwa huhate yang terdapat di Bitung dioperasikan dengan kapal penangkapan yang terbuat dari kayu berukuran 50 sampai dengan 80 GT. Daerah penangkapan di sekitar lokasi rumpon di Laut Sulawesi dan Laut Maluku. Hasil tangkapan yang diperoleh terdiri atas cakalang (Katsuwonus pelamis), madidihang (Thunnus albacares), baby tuna (Thunnus spp.), dan tongkol (Auxis spp.) serta hasil tangkapan sampingan yaitu lemadang (Coryphaena hippurus) dan sunglir (Elagatis bipinnulatus). Hasil analisis catch per unit of effort diperoleh bahwa nilai catch per unit of effort baby tuna (Thunnus spp.) mengalami kenaikan pada bulan Agustus 2004, dan cakalang (Katsuwonus pelamis) mengalami kenaikan pada bulan September 2004. Hasil analisis terhadap ukuran pertama kali cakalang (Katsuwonus pelamis) tertangkap oleh huhate 49,3 FLcm. Ukuran ini lebih panjang dibandingkan ukuran pertama kali cakalang (Katsuwonus pelamis) matang gonad. Sedangkan hasil analisis terhadap ukuran pertama kali madidihang (Thunnus albacares) tertangkap oleh huhate 51,6 FLcm. Ukuran ini lebih pendek dibandingkan ukuran pertama kali madidihang (Thunnus albacares) matang gonad. This paper presents the status of pole and line fishery in Bitung of North Sulawesi, consisting of description of fishing gear, fishing ground, catch composition, catch per unit of effort, and length at first capture. Data were collected during the period of 2004 until 2005. Results show that the pole and line in Bitung operated by wooden vessels of 50 until 80 GT. The fishing grounds were the waters around FADs location in Sulawesi Sea and Maluku Sea. Catch composition consists of skipjack tuna (Katsuwonus pelamis), yellow fin tuna (Thunnus albacares), baby tuna (Thunnus spp.), and frigate tuna (Auxis spp.), while the bycatch consisted of dolphinfish (Coryphaena hippurus) and rainbow runner (Elagatis bipinnulatus). Catch per unit of effort analysis shows that catch per unit of effort value of baby tuna (Thunnus spp.) increased on August 2004, whereas catch per unit of effort value of skipjack tuna (Katsuwonus pelamis) increased on September 2004. The length at first capture of skipjack tuna (Katsuwonus pelamis) was 49,3 FLcm. The catch size was bigger than the length at first maturity for skipjack tuna (Katsuwonus pelamis). The length at first capture of yellowfin tuna (Thunnus albacares) was 51,6 FLcm. This catch size was smaller than the length at first maturity for yellowfin tuna (Thunnus albacares).


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