Judul: Deskripsi Kecepatan Suara dan Pergerakan Gelombang Akustik di Selat Makassar
Abstrak: Selat Makassar, secara geografis terletak di antara Pulau Kalimantan dan Pulau Sulawesi. Dilihat dari letaknya, selat tersebut masuk jalur Alur Laut Kepulauan Indonesia (ALKI) dan salah satu jalur utama yang membawa masuknya massa air Arus Lintas Indonesia (ARLINDO). Penelitian ini bertujuan menganalisis kecepatan suara dan pola pergerakan gelombang akustik. Data diambil dari web marine.coperniccus.eu berupa data suhu, salinitas, kedalaman, dan kecepatan arus di 5 stasiun yang berbeda. Data yang telah diambil dikonversi menjadi data kecepatan suara, kemudian diubah menjadi data lingkungan. Model bellhop merupakan suatu metode beam tracing yang ditransmisikan melalui medium air laut menggunakan data lingkungan. Semakin dalam perairan, maka suhu akan semakin berkurang, sedangkan salinitas berlaku sebaliknya. Kecepatan suara sangat dipengaruhi suhu dibandingkan parameter lain. Dihasilkan gradien kecepatan suara negatif sehingga pancaran sinar sudut half beam 5° dan 15° merambat di dasar perairan sedangkan sudut half beam 30°menunjukkan pancaran sinar merambat di permukaan dan di dasar perairan. Rata-rata kecepatan suara tertinggi terdapat di Stasiun 4. Semakin besar sudut beam yang digunakan, maka jarak setiap pancaran sinar akan semakin menjauh
Keyword: depth, ray tracing, salinity, sound velocity, temperature

Judul: Karakteristik Hidroakustik Kolom Air di Perairan Selat Makassar
Abstrak: Perairan Selat Makassar bagian selatan merupakan kawasan perairan yang memiliki potensi sumberdaya perairan yang besar dan kaya nutrient. Daerah ini merupakan titik pertemuan massa air dari Samudera Pasific, dan Laut Flores. Penelitian mengenai stok ikan di Indonesia masih dalam tahap perkembangan, salah satu dari metode yang digunakan adalah aplikasi dari metode akustik. Penelitian ini bertujuan untuk menduga sebaran stok ikan pelagis di perairan Selat Makassar bagian selatan. Data diperoleh dari survei pada bulan Agustus – bulan September 2015 menggunakan Biosonic scientific echosounder system model DTCx. Data diolah menggunakan Echoview 4.8, Microsoft Office 2010, ArcGIS 10.2.2 dan Surfer. Analisis data difokuskan pada lapisan pelagis. Hasil menunjukkan bahwa gerombolan ikan di perairan Selat Makassar dan perairan Kota Balikpapan didominansi oleh gerombolan ikan yang berukuran sama, sedangkan pada perairan Kota Baru didominasi gerombolan ikan yang ukurannya beragam.
Keyword: Selat Makassar, hidroakustik, gerombolan ikan pelagis

Judul: Screening and Characterization of Bacterial Antagonists as Potential Agents for the Biological Control of the Chrysanthemum White Rust Disease
Abstrak: White rust disease caused by Puccinia horiana (Basidiomycetes: Uredinales) is the major problem on chrysanthemum plantation and caused yield lost until 100%. Biocontrol is an alternative way to control this disease. Therefore, the aims of this study are to obtain antagonist bacterial as biocontrol agents of chrysanthemum white rust disease, to identify the potential isolate and their biocontrol character, charachterized their biocontrol mechanism, and to know the role of their chitinolytic activity on germination of teliospore. The methods used in this study are selection of antagonistic bacteria which are able to control this disease in-vitro, characterized of potential antagonist bacteria with polymerase chain reaction of a 16S rRNA gene and physiology and biochemical character, characterized the mechanism of inhibition teliospore germination, and the role of chitinolytic activity in antagonism activity using transposon mutagenesis. The result showed that out of 29 bacterial isolates, 12 isolates had chitinolityc activity. The twelve isolates were the potential antagonist agents to control teliospore germination with percentage above 90%. Isolate K2 was the most potential antagonist bacteria to control this disease. This isolate could inhibit the germination up to 98% and had the highest chitinolytic activity among the isolates. Based on 16S rRNA gene partial sequences analysis and physiology and biochemical characters, this isolate was identified as Chromobacterium sp. The major mechanism was antibiosis. It is showed from the biocontrol activity which are bacteria’s cell colonization, lytic activity, and disintegrated of protoplasm. This bacteria produced cyanide acid (HCN) and phenazine beside chitinolytic enzyme. Chitinolytic activity was not a single factor in the mechanism of antibiosis but other secondary metabolic compounds produced by this bacteria also come into play. It is showed on the results of mutagenesis that transconjugants which had no chitinolytic activity was still able to inhibit germination of teliospora, whereas transconjugants which still had an activity equal to or smaller than wild type bacteria, the inhibitory were lower. It was indicated that chitinase was not the most important compound that inhibited the germination of teliopsore. There was another compound have the bigger role such as hydrogen cyanide, phenazine, or other substances produced by Chromobacterium sp..
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