Judul: Trajectory Model of Post Larvae, Availability of Natural Food and Suitability of Lobster Habitat in Lampung Bay
Abstrak: Teluk Lampung merupakan perairan dangkal semi tertutup yang terhubung dengan Selat Sunda dan menjadi salah satu penghasil komoditas lobster. Penelitian ini mengkaji trajektori post larva dengan memanfaatkan model arus 2 dimensi, serta mengetahui ketersediaan makanan alami dan kesesuaian habitat lobster di perairan Teluk Lampung. Parameter oseanografi diukur pada 15 stasiun dan disimulasikan melalui pemodelan arus. Ketersediaan makanan alami lobster diidentifikasi dengan metode DNA lingkungan. Berdasarkan hasil model trajektori, post larva yang masuk dari mulut teluk tersebar lebih luas karena dipengaruhi oleh variasi musiman arus dan hasil restocking di kepala teluk cenderung menyebar di kepala hingga tengah teluk karena arus di dalam teluk dipengaruhi pasang surut. Berdasarkan analisis DNA lingkungan teridentifikasi organisme yang diduga menjadi makanan alami lobster yang tergolong sebagai Mollusca, Annelida, Echinodermata, dan Crustacea, sedangkan post larva bersifat non-feeding phase. Arus di Teluk Lampung tergolong sebagai arus lemah hingga arus sedang. Suhu dan salinitas memiliki variasi musim dalam rentang nilai yang sesuai sebagai habitat lobster. Kadar DO dan pH bernilai optimum bagi lobster. Perairan Teluk Lampung sesuai sebagai habitat lobster dan dapat dimanfaatkan sebagai lokasi restocking lobster pada stadia post larva dan dewasa berdasarkan kondisi oseanografi dan ketersediaan makanan alaminya., Lampung Bay is a semi-enclosed shallow water which connected to Sunda Strait and produce lobster commodities. This study examined post larvae trajectory by utilizing 2-dimensional current model, and determined the availability of food and suitability of lobster habitat in Lampung Bay. Oceanographic parameters were measured at 15 stations and simulated through current modeling. The availability of food was identified by environmental DNA. Based on the results of trajectory model, post larvae that enter from the mouth of the bay spread widely because it’s influenced by seasonal variations of currents and restocking results at the bay head tend to spread from head to middle of bay because the currents in bay are influenced by tides. Based on eDNA analysis, organisms that are suspected of being natural food for lobsters are identified as Molluscs, Annelids, Echinoderms, and Crustaceans, while post larvae are a non-feeding phase. Current velocities are classified as weak to moderate. Temperature and salinity have seasonal variations that suitable for lobster. DO and pH levels are optimum for lobsters. Lampung Bay is suitable as habitat for lobsters and can be used as restocking location of post larvae and adult stages of lobsters based on oceanographic conditions and availability of food.
Keyword: current patterns, environmental DNA, Lampung Bay, lobster, post larvae trajectory, DNA lingkungan, Teluk Lampung, trajektori post larva, kesesuaian habitat

Judul: Kondisi Oseanografi dan Kesesuaian Lokasi Pengembangan Budidaya Lobster di Teluk Lampung
Abstrak: Indonesia memiliki potensi budidaya laut yang tinggi, yang perlu dimanfaatkan dengan baik dan optimal. Salah satu komoditas budidaya laut yang memiliki potensi untuk dikembangkan adalah lobster (Panulirus spp), karena memiliki nilai ekonomis yang tinggi. Pengembangan budidaya lobster memerlukan pemilihan dan penataan lokasi budidaya yang berdasarkan daya dukung dengan memperhatikan kondisi oseanografi. Penelitian ini bertujuan untuk menentukan kesesuaian lokasi budidaya lobster berdasarkan parameter oseanografi di Teluk Lampung. Pengumpulan data oseanografi dilakukan di enam stasiun yang berbeda dan data tersebut dianalisis secara spasial dengan menggunakan perangkat lunak ArcGIS. Metode analisis melibatkan interpolasi dan klasifikasi spasial, serta overlay data pada semua parameter oseanografi untuk memberikan skor berdasarkan matriks kesesuaian. Hasil analisis ini menghasilkan peta spasial kesesuaian lokasi budidaya lobster. Berdasarkan peta kesesuaian tersebut, ditemukan bahwa luas area yang sangat sesuai untuk budidaya lobster sistem keramba jaring apung adalah sekitar 49.941,60 hektar, sementara area yang sesuai mencapai 109.051,46 hektar, sedangkan yang tidak sesuai mencapai 2.184,94 hektar., Indonesia has a high potential for marine aquaculture that needs to be utilized effectively and optimally. One of the marine aquaculture commodities with significant development potential is lobster (Panulirus spp), known for its high economic value. The cultivation of lobsters requires the careful selection and arrangement of cultivation locations based on their carrying capacity, taking into account oceanographic conditions. This study aims to determine the suitability of lobster farming sites based on oceanographic parameters in Lampung Bay. Oceanographic data collection was conducted at six different stations and the data was spatially analyzed using ArcGIS software. The analysis method involves spatial interpolation and classification, as well as overlaying data on all oceanographic parameters to give a score based on the suitability matrix. The results of this analysis produce a spatial map of the suitability of lobster farming locations. Based on the suitability map, it was found that the area that is very suitable for lobster cultivation of floating net cage systems is around 49,941.60 hectares, while the corresponding area reaches 109,051.46 hectares, while the unsuitable area reaches 2,184.94 hectares.
Keyword: Keramba jaring apung, Kesesuaian budidaya, Lobster, Oseanografi

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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