Judul: Suatu Studi Tentang daerah Penangkapan Ikan Madidihang (Thunnus albacares) untuk Komoditi Ekspor di Perairan Indonesia
Abstrak: Yellowfin Tuna (Thunnus albacares) merupakan salah satu komoditi hayati laut yang mempunyai arti ekonomis yang cukup tinggi sebagai komoditas ekspor. Harga lelang ikan Yellowfin tuna segar yang tercatat pada bulan Agustus 1991 pasar Tsukuji dan Shimizu adalah berkisar antara USD1,45 sampai USD20.34 untuk tiap satu kilogramnya (Anonimous, 1991). Adapun tujuan dari penelitian ini adalah untuk mengetahui pola musim penangkapan dan mengkaji daerah penangkapan keberadaan Yellowfin tuna (Madidihang, albacares) selama lima tahun (1981 - Thunnus 1985) dari data PT Perikanan Samodra Besar, dengan pendekatan nilai hook rate. Tentunya dengan harapan agar hasil penelitian ini dapat bermanfaat untuk membantu mempermudah penentuan daerah penangkapan Yellowfin tuna dalam pengoperasian longline untuk komiditi fresh tuna.
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Judul: Estimasi Daerah Penangkapan Madidihang (Thunnus albacares) dengan Tonda di Selatan Teluk Palabuhanratu
Abstrak: Yellowfin tuna becomes a major of Indonesian’s export commodity because of it’s demand and high selling price. To fulfill the needs of yellowfin tuna are highly influenced by the condition of fishing ground. Therefore, information about the potential yellowfin tuna’s fishing grounds is needed by fisheries. The objectives of this research are to determine the composition length size and productivity of yellowfin tuna, to determine the spatial-temporal distribution of sea surface temperature and chlorophyll-a, and to estimate the potential fishing ground of yellowfin tuna in southern bay of Palabuhanratu. This research was conducted from May to August 2013. The research show that the dominant catched pelagic fish are skipjack (43%), yellowfin tuna (37%), bigeye tuna (12%), Indo Pacific blue marlin (5%), and common dolphin fish (3%). In addition, the average distributions for sea surface temperature is 27.6-30.6ºC. Meanwhile the average distributions for chlorophyll-a is 0.1-0.2 mg/m3. Moreover, the yellowfin tuna’s fishing ground was estimated by using four indicators, namely length size of yellowfin tuna, catch per unit effort (CPUE), sea surface temperature, and chlorophyll-a concentration. Finally, the potential fishing ground of yellowfin tuna in the south Palabuhanratu bay is located in the southern part which is connected with international sea (exclusive economic zone) comparing to the area in southwestern part closer to the coast.
Keyword: sea surface temperature (SST), southern bay of Palabuhanratu, yellowfin tuna, chlorophyll-a, fishing ground

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology