Judul: EStimasi Potensi Abandoned, Lost and Discarded Fishing Gear Jaring Rajungan yang Berbasis di Pelabuhan Perikanan Nusantara Muara Angke
Abstrak: Jaring rajungan merupakan alat tangkap yang termasuk ke dalam jaring insang yang memiliki potensi untuk terjadinya ALDFG (Abandoned, Lost, and Discarded Fishing Gear). Penelitian ini bertujuan untuk mengestimasikan potensi ALDFG dan sampah perbekalan dari perikanan jaring rajungan serta mengidentifikasi penyebab dan upaya penanggulangannya. Pengambilan data dilakukan dengan metode survei dan observasi lapang dengan analisis yang digunakan yaitu analisis deskriptif. Hasil penelitian menunjukan bahwa estimasi potensi jaring rajungan yang hilang (lost) dalam 1 bulan sebanyak 12 unit (240 piece) dengan berat total 780 kg. Sementara dalam 1 tahun diestimasikan sebanyak 120 unit (2.400 piece) dengan berat total 7.800 kg dengan kerugian Rp396.000.000. Estimasi potensi jaring rajungan yang ditinggalkan (abandoned) dalam 1 bulan sebanyak 0,25 unit (5 piece) dengan berat total 16,25 kg, sementara dalam 1 tahun diestimasikan sebanyak 2,5 unit (50 piece) dengan berat total 162,5 kg dan kerugian Rp8.250.000. Sampah perbekalan nelayan jaring rajungan yang berpotensi dibuang kelaut yaitu sebanyak 45 kg per bulan dan sebanyak 450 kg per tahunnya. Penelitian ini mengusulkan upaya penanggulangan berupa sosialisasi mengenai dampak buruk ALDFG dan ghost gear, mewajibkan pelaporan kehilangan alat tangkap, pemberian insentif dan penggunaan gear marking., Crab gillnet is a fishing gear intended for catching crabs that have the potential to cause Abandoned, Lost, and Discarded Fishing Gear (ALDFG). This research aims to estimate the potential for ALDFG and waste resulting from crab gillnet fisheries and to identify the causes and mitigation efforts. Data collection was carried out using survey methods and field observations, and then the data were analyzed descriptively. The research showed that the estimated lost crab gillnets potential in one month was 12 units (240 pieces) with a total weight of 780 kg. Meanwhile, in one year it is estimated about 120 units (2,400 pieces) with a total weight of 7,800 kg or with a total loss value of IDR 396,000,000. The estimated abandoned crab gillnets potential in one month was 0.25 units (5 pieces) with a total weight of 16.25 kg, while in one year it is estimated about 2.5 units (50 pieces) with a total weight of 162.5 kg and a loss of IDR 8,250,000. The amount of crab gillnet fishers supplies that have the potential debris to be thrown into the sea is 45 kg per month or about 450 kg per year. This study proposes a mitigation efforts including dissemination of the negative impacts of ALDFG and ghost gear to the fishers, a reporting program of lost fishing gear, providing incentives, and the implementation of gear marking program.
Keyword: ALDFG, debris, fishing gear, gillnet, PPN Muara Angke

Judul: Estimation of Potential Ghost Gear in Gillnet Fisheries and its Prevention Efforts at Karangsong Fish Landing Base, Indramayu
Abstrak: Ghost gear merupakan salah satu bagian dari marine debris yang diakibatkan oleh alat tangkap yang hilang, dibuang, dan ditinggalkan di perairan. Alat tangkap yang berpotensi besar menyebabkan ghost gear adalah jaring insang. Sebanyak 87,6% alat tangkap yang beroperasi di Karangsong adalah jaring insang. Tujuan penelitian ini adalah mendeskripsikan perikanan jaring insang di PPI Karangsong, mengestimasi jumlah ghost gear, mengidentifikasi faktor penyebabnya dan merumuskan upaya penanggulangan untuk mengurangi terjadinya ghost gear di PPI Karangsong. Penelitian ini dilakukan di PPI Karangsong, menggunakan metode survei. Analisis yang digunakan adalah analisis deskriptif dan analisis statistik. Hasil penelitian menunjukkan mayoritas kapal yang digunakan di PPI Karangsong adalah <5 GT, dengan nelayan yang merupakan nelayan penuh. Jumlah ghost gear yang terjadi dalam satu tahun terakhir sebanyak 2.464 piece atau 123.214 m dan kerugian mencapai Rp10.338.204.580. Penyebab terjadinya ghost gear disebabkan oleh beberapa faktor yaitu tersangkut karang, konflik, dan cuaca yang buruk. Beberapa cara yang direkomendasikan untuk mengurangi ghost gear yaitu sosialisasi ghost gear, standarisasi gear marking, implementasi pelaporan ghost gear, dan penerapan teknologi modern., Ghost gear is part of marine debris caused by abandoned, lost, or otherwise discarded fishing gear in the waters. Fishing gear that has the most significant potential to cause ghost gear is gillnet. Fishers operate this fishing gear as dominant as 87,6% in Karangsong. The research aims are to describe the fishery gillnet in PPI Karangsong, estimate the number of ghost gear, identify the causes, and formulate efforts to reduce the number of ghost gear in Karangsong. The research was conducted at PPI Karangsong, based on survey methods. A descriptive analysis dan statistical analysis was applied in this study. The result showed the majority of vessels used in PPI Karangsong were <5 GT, with a fisher who is a full-time job. The number of ghost gears in the past year was 2,464 pieces or 123,214 m, and losses reached 10,338,204,580 IDR. Ghost gear is caused by snagging, conflict, and bad weather. The recommended efforts to minimize ghost gear are socialization, gear marking standardization, implementation of ghost gear reporting, and application of modern technology.
Keyword: Fishing gear, Ghost gear, Gillnet, Marine debris, PPI Karangsong

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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