Judul: Karakteristik Populasi Panenan (Amyda cartilaginea) di Kabupaten Sambas dan Kabupaten Ketapang Kalimantan Barat
Abstrak: Indonesia merupakan salah satu negara penghasil labi-labi (Amyda cartilaginea) di dunia. Penangkapan labi-labi di Indonesia dilakukan untuk memenuhi kebutuhan dalam negeri (konsumsi dan pet) dan untuk ekspor (Mardiastuti & Soehartono 2003). Di Indonesia status konservasi labi-labi belum dilindungi undang-undang, tetapi secara Internasional, spesies tersebut masuk ke dalam Appendix II CITES (CITES 2010) dan dikategorikan vulnerable (rentan) pada Red Data Book IUCN (IUCN 2010). Lokasi tangkapan labi-labi dari alam yang utama adalah di Kalimantan dan Sumatera. Kalimantan Barat merupakan salah satu daerah pemasok labi-labi, pada tiga tahun terakhir (2007 – 2009) mendapat kuota yang cukup tinggi yaitu 4.000 ekor setelah Sumatera Utara (rata-rata 9.250 ekor) dan Kalimantan Timur sebanyak 5.000 ekor pertahun (Ditjen PHKA 2007; 2008; dan 2009). Di Kalimantan Barat, berdasarkan informasi dari pengumpul besar yang merangkap eksportir diketahui bahwa dua lokasi yang merupakan kantong tangkapan labi-labi adalah Kabupaten Ketapang dan Kabupaten Sambas. Penelitian ini dilakukan karena saat ini tingkat penangkapan labi-labi dari alam cukup tinggi, sementara data dan informasi tentang kondisi populasi di alam masih sangat terbatas. Lokasi penelitian adalah di Kabupaten Sambas dan Kabupaten Ketapang untuk tingkat pemancing dan pengumpul, dan di Pontianak untuk tingkat eksportir. Pengambilan data dilakukan ± 2 bulan yaitu dari bulan Maret 2010 sampai dengan bulan April 2010. Tujuannya adalah untuk (1) mengetahui parameter demografi (seks rasio, mortalitas dan kelas umur) populasi panenan di tingkat pemancing, pengumpul dan eksportir (2) mengetahui parameter morfometri populasi panenan (3) menduga populasi alami di lokasi-lokasi tangkapan dan (4) fluktuasi tangkapan per periode tangkap.
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Judul: Tata Niaga, Parameter Demografi Populasi Panenan dan Karakteristik Habitat Labi-labi Amyda cartilaginea (Boddaert 1770) di Provinsi Jambi.
Abstrak: Asian soft-shell turtle (Amyda cartilaginea Boddaert, 1770) has been recorded as the most harvested turtle species in Indonesia, mainly for consumption purpose in oriental countries. In order to prevent over-exploitation and the declining of the population, harvesting has been limited by quota. In practice, the harvesting still showed an enormous number and the determination of the quota itself was not yet based on the data of Amyda population. This research was aimed to identify mortality rate through identification of the trading system since for highly-valued species harvesting was the major cause of mortality. The demographyc and morphometric parameters were measured to characterize the harvested population by its size, sex ratio, age-class and range of bodymass and carapace length. Twenty dissected speciments were observed to study the reproduction condition of different size of Amyda, thus used to estimate potential lost caused by harvesting. Amyda’s habitat was characterized by measuring 9 biophysical variables of each of 90 fishing plots in 16 rivers and 3 lakes. The result showed that the size of harvested population of Amyda at the trader level was different from one to another, but showed similar trends of domination in sex and age class which were adult females and reaching the number of 58.28%. The people dealing with the harvesting activities of Amyda had no preference for size and sex of the harvested animal. Reproduction condition of the observed Amyda showed that at the size of five kilograms, the females were at the age of maturity. Kolmogorov-Smirnov test on the habitat biophysical variable on stream showed that Amyda had no habitat preference.
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Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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