Judul: Study on the Aggregation Mechanism of Small Pelagic Fish around Rumpon and Its Fisheries of Development in Pasauran Waters, Province of Banten
Abstrak: Rumpon (Fish Aggregating Device) is an auxiliary gear operated to attract and aggregate fish. The use of rumpon for fishing activities has improved the effectivity and efficience of several fishing gear. However, the fast growing of rumpon utilization has raised a great concern on the sustainability of the fish resources. The rumpon management for responsible fisheries should consider the aspects of biology, location, environment, fishing gear, social and economic. The aggregation mechanism of pelagic fish around rumpon has not fully understood and its usage in a responsible manner further elaboration also needed. For this purpose, analysis were conducted on the anatomy and morphology of 3 kinds of rumpon's attractor materials, i.e Cocos nucifera, NypaJLuctican and Areca catechu leaves. The genus composition of plankton and periphyton were identified, obse~-vationosn fish behavior, stomach content, Gonado Somato Index were carried out. Experimental fishing was conducted by using payang bugis. The result show that the Cocos nucifera leaves are the best attractor material based on the thickness of cuticle, thickness of epidermis, density of periphyton, and number of fish species in all seasons. Further, the Gonado Somato Index (GSI) of small pelagic fish were caught around rumpon are GSI I 4%, GSI I1 33% and GSI I11 35%. This result indicated that the small pelagic fish caught around rumpon are 'immature fish' and could cause recruitment overfishing. The periphyton in the attractors were also found in the stomach content of 6 small pelagic species fish around rumpon. The aggregation mechanism aggregation of pelagic fish around rumpon, therefore, more likely caused by food chain process, beginning with colonization of microorganism on leaves attractor, aggregation of micro organism prey around rumpon, aggregation of filtering and predator fish. Next, application of Hilborn and Medley Model on the rumpon fisheries in Pasauran waters revealed that the optimum number of rumpon is 4 units, for the water area of 11 5.4 km2, and the mean distance of each rumpon is 5 km (about 3 nautical miles). The 4 units rumpon in Pasauran waters could render 154.4 ton of total catch/year with a profit of 38.2 million rupiahlyear. The rumpon fisheries in Pasauran have not met with the criteria of the Code of Conduct for Responsible Fisheries. The GSI of small pelagic fish were caught around rumpon indicated that the rumpon could cause recruitment overfishing. Rationalization of the existing 45 to 4 units rumpon in Pasauran waters is recommended to ensure the sustainability of the fisheries.
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Judul: Teknologi dan Manajemen Perikanan Tuna Berbasis Rumpon yang Berkelanjutan di Prigi, Jawa Timur
Abstrak: Rumpon atau Fish Agregation Device (FADs) merupakan suatu alat bantu penangkapan ikan yang berfungsi untuk memikat gerombolan ikan agar terkonsentrasi pada satu lokasi. Penggunaan rumpon dalam jangka pendek dapat meningkatkan produksi hasil tangkapan nelayan dan efisiensi upaya penangkapan ikan. Sedangkan pada jangka panjang dikhawatirkan akan berdampak negatif terhadap kelestarian sumberdaya ikan. Penelitian ini dilakukan di Perairan Selatan Prigi dan Pelabuhan Perikanan Nusantara (PPN) Prigi, Jawa Timur. Penelitian ini bertujuan untuk mengetahui status perikanan tuna berbasis rumpon di Prigi, kelayakan teknis, ekologis, dan ekonomis, serta optimasi jumlah rumpon dan armada penangkapan yang optimal di lokasi penelitian. Beberapa metode analisis diterapkan pada penelitian ini. Untuk mengetahui kelayakan teknis dalam penentuan jumlah unit armada yang optimal beroperasi di sekitar rumpon menggunakan analisis Linear Goal Programming (LGP). Untuk mengetahui status pemanfaatan sumberdaya ikan tuna digunakan analisis surplus produksi seperti fishing power indeks (FPI), catch per unit effort (CPUE) dan maximum sustainable yield (MSY). Untuk mengetahui kondisi morfometrik ikan yang ditangkap secara temporal digunakan model pertumbuhan dengan analisis hubungan panjang dan berat. Informasi mengenai musim penangkapan digunakan untuk menduga pola musim penangkapan ikan. Kelayakan usaha dilakukan untuk mengkaji keuntungan (profitability) atau kerugian dari suatu usaha. Ada dua macam analisis yang digunakan yaitu: analisis usaha (pendapatan usaha, payback period, dan analisis berimbang antara penerimaan dan biaya), dan analisis kriteria investasi (net present value, internal rate of return dan net benefit cost - rasio) Hasil penelitian menunjukkan status pemanfaatan sumberdaya ikan tuna berbasis rumpon di wilayah sekitar Perairan Selatan PPN Prigi telah tereksploitasi secara berlebih pada tingkat pengupayaan yang melampaui batas maksimum. Penggunaan rumpon sebagai alat bantu penangkapan layak secara teknis karena memenuhi persyaratan kriteria umum komponen rumpon, layak secara ekonomis karena memiliki nilai NPV > 0, Net B/C > 1, dan IRR > tingkat suku bunga yang berlaku, tetapi tidak layak secara ekologis terutama karena hasil tangkapan jenis ikan tuna didominasi ukuran yang belum layak tangkap. Strategi optimasi pengelolaan pemanfaatan sumberdaya perikanan di PPN Prigi dengan alokasi optimum unit armada penangkapan yang direkomendasikan untuk armada jaring insang hanyut sebanyak 43 unit dan armada tonda sebanyak 63 unit. Jumlah rumpon yang direkomendasikan sebanyak 33 unit pada wilayah luas perairan tempat penyebaran rumpon yang berhasil didata sebesar 8.940 km²
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Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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