Judul: Dinamika komunitas plankton dan potensinya sebagai pakan alami di kolam pemeliharaan larva ikan nilem (Osteochilus hasselti C.V.)
Abstrak: Plankton merupakan mikroorganisme yang keberadaannya cukup penting di ekosistem perairan. Selain sebagai produsen, plankton juga penghasil oksigen dan merupakan pakan alami bagi ikan. Melimpahnya plankton di perairan di harapkan dapat meningkatkan produksi ikan. Tujuan penelitian adalah mempelajari dinamika komunitas plankton dan mengetahui potensinya sebagai pakan alami bagi larva ikan nilem pada pemberian komposisi pupuk yang berbeda.
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Judul: Komposisi Dan Kelimpahan Makrozoobenthos Di Kolam Budidaya Ikan Nila (Oreochromis niloticus Trewavas) Darmaga: Yang Di Pupuk Kotoran Ayam
Abstrak: Lingkungan hidup ekosistem perairan yang terdiri dari lingkungan abiotik dan biotik mempunyai arti luas. Antara lain menyangkut sifat fisika, kimia dan biologi tempat tinggal organisma hidup yang dapat berinteraksi di dalam suatu ekosistem. Benthos sebagai organisma dasar perairan mempunyai habitat yang relatif tetap. Organisma dasar merupakan salah satu komponen rantai makanan yang penting dalam perairan, dimana kualitas dan kuantitasnya dapat digunakan sebagai indikator produktivitas kolam (Liang dalam Sunowo, 1980). Organisma dasar (benthos) mempunyai beberapa peranan di dalam komunitas akuatik. Organisma dasar terlibat di dalam proses pendaur ulang dari bahan-bahan organik yang terdapat di dasar perairan; dan dalam hal ini organisma ini penting sebagai rantai kedua dan ketiga dalam hubungan trophic dari komunitas akuatik (Lind, 1979). Menurut Hickling (1971) pemberian pupuk organik akan merangsang perkembangan organisma dasar, karena selain dapat memperkaya hara perairan, pupuk organik juga merupakan habitat yang baik bagi organisma tersebut. Perubahan kualitas air sangat mempengaruhi kehidupan benthos, yang selanjutnya mempengaruhi komposisi dan besarnya populasi.
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Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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