Judul: Fish Community Structure in the Seagrass Ecosystem of Tidung Besar Island, Seribu Islands
Abstrak: Lamun mempunyai peranan penting sebagai tempat pemijahan, pengasuhan, perlindungan, dan mencari makan biota laut, seperti ikan. Akan tetapi, struktur komunitas ikan di ekosistem padang lamun Pulau Tidung Besar masih belum dikaji. Penelitian ini bertujuan menganalisis struktur komunitas ikan di ekosistem padang lamun Pulau Tidung Besar saat kondisi pasang dan surut. Pengumpulan data dilakukan pada bulan Oktober hingga Desember 2023. Pengambilan sampel ikan dilakukan dengan menggunakan jaring insang dengan empat ukuran mata jaring, panjang, dan lebar yang berbeda. Analisis contoh ikan dilakukan di laboratorium. Selama penelitian terkumpul sebanyak 1144 individu ikan yang terdiri dari 12 ordo, 30 famili, dan 70 spesies. Komposisi ikan didominasi oleh Dischistodus chrysopoecilus (betok hitam) sebesar 612 Ind/m2. Kelimpahan dan dominasi spesies lebih tinggi pada saat air pasang, sedangkan kekayaan, keanekaragaman, dan kemerataan spesies lebih tinggi pada saat air surut. Keanekaragaman ikan di Pulau Tidung Besar termasuk ke dalam kategori sedang dengan kondisi yang cenderung stabil., Seagrass has an important role as a habitat for spawning, nurturing, protecting and foraging for marine biota, such as fish. However, the structure of fish communities in the Tidung Besar Island seagrass ecosystem has not yet been studied. This research aims to analyze the structure of fish communities in the seagrass ecosystem of Tidung Besar Island during high and low tide conditions. Fish sampling was carried out using gill nets with four different mesh sizes, lengths and widths. Analysis of fish samples is carried out in the laboratory. During the research, 1144 individual fish were collected consisting of 12 orders, 30 families and 70 species from October to December 2023. The fish composition was dominated by Dischistodus chrysopoecilus (white-spot damsel) at 612 Ind/m2. The abundance and dominance of species is higher at high tide, while species richness, diversity and evenness are higher at low tide. Fish diversity on Tidung Besar Island is included in the medium category with conditions that tend to be stable.
Keyword: community structure, fish, seagrass ecosystem, Tidung Besar Island

Judul: Macrozoobenthos Community Structure in Seagrass Ecosystem in Tidung Island, Seribu Islands
Abstrak: Pulau Tidung terbagi menjadi dua gugusan pulau, yaitu Pulau Tidung Besar dipengaruhi aktivitas antropogenik, dan Pulau Tidung Kecil tidak dipengaruhi aktivitas antropogenik. Salah satu ekosistem di Pulau Tidung yang keberadaannya kurang diperhatikan ialah ekosistem lamun. Penelitian ini bertujuan menganalisis struktur komunitas makrozoobenthos pada ekosistem lamun di kedua pulau. Stasiun pengambilan contoh terdiri dari dua stasiun, yakni di Utara Tidung Besar dan di Utara Tidung Kecil dengan menggunakan metode garis transek. Analisis yang dilakukan meliputi kepadatan makrozoobenthos, indeks ekologi, dan keterkaitan makrozoobenthos dengan parameter pendukung. Makrozoobenthos yang ditemukan di Pulau Tidung terdiri dari 34 ordo, 57 famili, 76 genus didominasi oleh kelas Gastropoda. Rata-rata kepadatan makrozoobenthos pada masing-masing stasiun sebanyak 24 ind/m2 dan 20 ind/m2. Indeks ekologi menunjukkan bahwa makrozoobenthos berada dalam kondisi yang baik. Hasil PCA menunjukkan bahwa kepadatan makrozoobenthos memiliki hubungan yang kuat dengan suhu., Tidung Island has two islands, namely Tidung Besar Island which is affected by anthropogenic activities, and Tidung Kecil Island which is less affected by anthropogenic activities. One of the ecosystems in Tidung Island whose existence is less considered is seagrass ecosystem. This study aims to analyze the structure community of macrozoobenthos in seagrass ecosystems on both island. The sampling stations consisted of two stations, North of Tidung Besar and North of Tidung Kecil using the line transect method. The analysis included macrozoobenthos density, ecological index, and macrozoobenthos association with supporting parameters. Macrozoobenthos found in Tidung Island consisted of 34 orders, 57 families, 76 genus dominated by Gastropoda class. The average density of macrozoobenthos at each station was 24 ind/m2 and 20 ind/m2. Ecological index shows that macrozoobenthos are in good condition. PCA results showed that macrozoobenthos density had a strong relationship with temperature.
Keyword: water quality, seagrass, anthropogenic, gastropoda, gastropoda, macrozoobenthos

Judul: Sintesis Flavonol melalui 2’-Hidroksikalkon
Abstrak: Flavonol is a class of flavonoids commonly found in fruits and vegetables. Flavonol is very useful, especially in food sector and health. In this study, flavonol unsubstituted was successfully synthesized from an intermediate material 2’-hydroxychalcone. The 2’-hydroxychalcone was synthesized by Claisen-Schmidt condensation method between o-hydroxyacetophenone and benzaldehyde using 4 different catalysts, namely KOH 60%, solid pellet of KOH-grinding technique, BF3-Et2O, and NaH in DMF. The KOH 60% was the best catalyst, giving the highest yield (57%). Afterward, the flavonol was synthesized in 1-stage oxidation cyclization of o-hydroxyacetophenone using Algar-Flynn-Oyamada (AFO) reaction, giving 76%. The flavonol total yield from 2’-hydroxychalcone was 43%. All synthesized products were characterized by their melting points and their spectra. The success of the synthesis flavonol opens the way to synthesis of useful flavonol derivatives such as quercetin and kaempferol
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