Judul: Dinamika populasi ikan lemuru, Sardinella Lemuru Bleeker 1853 (Pisces: Clupeidae) di perairan Selat Bali dan alternatif pengelolaannya
Abstrak: Perairan Selat Bali merupakan suatu bentuk perairan yang relatif sempit, berbentuk corong dengan luas kira-kira 2.500 km2 , produktivitasnya tinggi karena ter jadi proses penaikan air mulai kira-kira bulan April sampai Oktober. Ikan lemuru merupakan jenis ikan yang dominan yang tertangkap di perairan tersebut, produksinya berkisar antara 1.583-21.363 ton (32,85-97,9%) atau rata-rata 10.708 ton (78,46%) per tahun, sedangkan setiap bulannya berkisar antara 501-1.441 ton (65,86-92,89%) atau rata-rata 894 ton (76,07%) dalam periode 1984 sampai dengan 1989 (Data hanya dari KUD Mina Karya, Pengambengan, Bali).
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Judul: Distribution and Abundance Analysis of the "Lemuru" (Sardinellla lemuru Bleeker, 1853) in Bali Strait Waters: Its Relation with Fishing Optimization
Abstrak: lkan lemuru ( Sardine/la /emuru) merupakan sumber daya perikanan taut yang sangat penting dan spesifik di perairan Selat Bali, dengan rata-rata produksi tahunan mencapai 80% dari produksi total perikanan laut. Produksi perikanan lemuru di perairan Selat Bali ternyata sangat berfluktuasi baik secara musiman ataupun tahunan. Untuk menangkap ikan lemuru di perairan Selat Bali digunakan alat tangkap pukat cincin dan dilakukan oleh nelayan yang berasal dari dua propinsi, yakni Jawa Timur (Muncar) dan Bali (Pengambengan). Perairan Selat Bali mempunyai bentuk unik yang menyerupai corong yaitu menyempit di utara dengan lebar sekitar 1 mil dan melebar di selatan sekitar 28 mil. Perairan sebelah utara berhubungan dengan Laut Bali, sedang di sebelah selatan berhubungan dengan Samudera Hindia. Dengan topografi seperti ini, karakteristik perairan Selat Bali sangat dipengaruhi oleh massa air yang berasal dari Samudera Hindia dan diperkirakan sangat bervariasi baik secara spasi,al ataupun temporal (musiman). Terjadinya variasi parameter oseanografi, baik secara spasial maupun temporal akan berpengaruh langsung atau tidak langsung terhadap penyebaran dan kelimpahan ikan lemuru. lkan lemuru juga memiliki sifat seperti kebanyakan jenis ikan clupeids lainnya yaitu senang hidup bergerombol, membentuk gerombolan besar yang dinamakan schooling. lnformasi tentang karakteristik (panjang, tinggi, densitas, dan kedalaman) gerombolan ikan lemuru ini sangat penting bagi keberhasilan penangkapan dengan pukat cincin yang dioperasikan dengan cara berburu tanpa menggunakan alat bantu pengumpul ikan. De_mikian juga dengan informasi tentang ukuran ikan lemuru yang akan ditangkap sangat diperlukan untuk penentuan pola penangkapan yang optimum sehingga tidak mengganggu kelestarian sumber dayanya. Penelitian ini dilakukan dengan tujuan: (1) mengkaji penyebaran dan kelimpahan ikan lemuru berdasarkan musim dan hubungannya dengan parameter oseanografi, (2) mendapatkan informasi tentang karakteristik gerombolan ikan lemuru berdasarkan waktu (musim dan tengah harian), (3) mengetahui pola pengelompokan ukuran ikan berdasarkan daerah penangkapan dan waktu (bulan), dan (4) menyusun pola penangkapan ikan lemuru yang optimum dengan memperhatikan kaidah-kaidah pengelolaan sumber daya perikanan., small pelagic resources in Bali Strait waters. Some factors have played important roles in the variation of lemuru production, among others, are the oceanographic parameters. The objectives of this research are: (1) to study the distribution and the abundance of lemuru specifically their relationship to oceanographic parameters, (2) to analyze the size structure of lemuru caught by the purse seine, (3) to evaluate the characteristics of lemuru schools in different seasons, (4) to develop an optimum fishing pattern for lemuru purse seine fisheries. This research was carried out in two years, from 1996 to 1998 in the Bali Strait waters, applying acoustic methods and the analysis of its abundance index (catch per unit effort, CPUE). Oceanographic observations were also carried out along cruise tracks using research vessel. The analytical hierarchy process was applied for determining the optimum fisheries pattern. In Bali Strait, lemuru was abundant at the end of southeast monsoon (August) and transition season-2 (September-November) which was indicated by a high CPUE. The acoustic data analysis showed that during transition season-2 the abundance pelagic fish was higher than during transition season-1. Upwelling was occurred during southeast monsoon in Bali Strait, characterized by low temperature, high salinity, and phytoplankton was abundant. · Using factorial correspondence analysis, it can be identified four
Keyword: Echolocation Sonar, Ikan Lemuru, sardinella Lemuru

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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