Judul: Diversity and Associations of Gastropods in the Mangrove Ecosystem of Lancang Island, Kepualauan Seribu, DKI Jakarta
Abstrak: Ekosistem mangrove merupakan area pada batas pasang surut dengan gradien sifat lingkungan yang tajam. Salah satu biota yang dapat hidup pada ekosistem ini adalah gastropoda. Penelitian ini bertujuan untuk mengetahui keanekaragaman dan hubungan asosiasi gastropoda dan mangrove yang ada di Pulau Lancang, Kepulauan Seribu, DKI Jakarta. Penelitian ini dilakukan menggunakan metode transek garis dan transek kuadran, serta pengukuran kualitas air dan fraksinasi sedimen di empat stasiun. Hasil penelitian menunjukkan bahwa kualitas perairan di Pulau Lancang tergolong baik dengan tipe substrat berpasir. Genus mangrove yang berhasil diidentifikasi adalah Rhizophora, Sonneratia, dan Avicennia. Gastropoda yang teridentifikasi terdiri dari 12 spesies, yang berasal dari 11 genus dan 9 famili. Spesies dengan jumlah terbanyak yaitu Terebralia palustris, Monodonta labio, dan Littoraria scabra. Hasil analisis koresponden menunjukkan bahwa terdapat dua pengelompokkan komunitas gastropoda dengan asosiasi tertinggi pada mangrove Rhizophora. Spesies gastropoda yang berasosiasi dengan Rhizophora adalah Littoraria scabra, Monodonta labio, Tectus pyramis, Nerita albicilla, Cerithidea cingulata, Terebralia palustris, dan Telescopium telescopium., Mangrove ecosystem is an area at the tidal boundary with a sharp gradient in environmental characteristics. One type of biota that can live in this ecosystem is gastropods. This research aimed to understand the diversity and association between gastropods and mangrove on Lancang Island, Kepulauan Seribu, DKI Jakarta. The study utilized line and quadrant transect methods, along with water quality and sediment fractination were measured at four stations. The research findings indicate that the water quality on Lancang Island is relatively good, with substrates dominated by sand. Mangrove genera identified were Rhizophora, Sonneratia, and Avicennia. Gastropods comprised of 12 species, originating from 11 genera and 9 families. The species with highest occurrence were Terebralia palustris, Monodonta labio, and Littoraria scabra. Correspondencce analysis results show that there are two groupings associated, with the highest gastropods composition associated with Rhizophora mangroves. Species associated with Rhizophora include Littoraria scabra, Monodonta labio, Tectus pyramis, Nerita albicila, Cerithidea cingulata, Terebralia palustris, and Telescopium telescopium.
Keyword: Association, Diversity, Gastropods, Mangrove ecosystem

Judul: Diversity and Association of Gastropods in the Seagrass Ecosystem on Tidung Kecil Island, Seribu Islands.
Abstrak: Gastropoda berperan dalam proses dekomposisi dan kestabilan ekosistem. Penelitian ini bertujuan menganalisis keanekaragaman dan asosiasi gastropoda pada ekosistem lamun Pulau Tidung Kecil, Kepulauan Seribu. Pengamatan menggunakan metode Seagrass Watch di empat stasiun ekosistem lamun. Tiap stasiun diukur parameter lingkungan perairan dan sedimen. Gastropoda yang ditemukan terdiri dari 53 spesies yang tergolong dalam 13 famili dengan kepadatan tertinggi di seluruh stasiun dimiliki oleh famili Cerithiidae yaitu 1503 ind/m2. Spesies dengan nilai kepadatan tertinggi adalah Cerithium punctatum di Stasiun 3 sebesar 303 ind/m2. Spesies lamun yang ditemukan yaitu Thalassia hemprichii, Enhalus acoroides, Cymodocea rotundata, dan Halophila ovalis. Kualitas perairan di ekosistem lamun masih berada dalam baku mutu gastropoda dengan substrat didominasi pasir. Analisis korespondensi (CA) menunjukkan terdapat tiga kelompok utama asosiasi gastropoda dengan vegetasi lamun. Komposisi gastropoda pada lamun jenis T. hemprichii dan lamun campuran memiliki nilai tertinggi. Analisis korelasi Pearson menunjukkan kerapatan lamun dengan kepadatan gastropoda memiliki hubungan sangat kuat dan searah., Gastropods significantly contribute to ecosystem stability and decompositions. This study examines the diversity and association of gastropods in seagrass ecosystem of Tidung Kecil Island, Seribu Islands. Observations were conducted at four stations using the Seagrass Watch method, measuring aquatic and sedimentary parameters. Gastropods found consisted of 53 species from 13 families with the highest density throughout the stations is Cerithiidae of 1503 ind/m2. The species with the highest density value is Cerithium punctatum at Station 3 of 303 ind/m2. Seagrass species found were Thalassia hemprichii, Enhalus acoroides, Cymodocea rotundata, and Halophila ovalis. The water quality in the seagrass ecosystem aligns with the gastropod life standards with sand-dominated substrate. The results of correspondence analysis (CA) revealed three main groups of gastropod associations with seagrass vegetation. The composition of gastropods in T. hemprichii seagrass and mixed seagrass has the highest value. Pearson correlation showed that seagrass density and gastropod density have a very strong and proportional relationship.
Keyword: association, diversity, gastropods, seagrass

Judul: Pembuatan Film Tipis Cu2ZnSnS4 sebagai Lapisan Penyerap Cahaya pada Sel Surya Menggunakan Metode Elektrodeposisi
Abstrak: Thin film of Cu2ZnSnS4 (CZTS) is an alternative semiconductor used as light absorber layer on solar cell. CZTS can replace silicon that commonly used as commercial semiconductor. The advantage of using CZTS as absorber layer is due to the abundance of its chemical composer on earth, and its high value of absorption coefficient. The absorber layer was made by using electrodeposition method on ITO glass substrates. The films were deposited at room temperature using potentiostatic mode with a potential of –1.05 V for 30, 45, and 60 minutes. After that, the films were annealed at two different temperatures, 180 ºC and 500 °C, for 45 minutes in N2/H2S atmosphere. Based on X-ray diffraction analysis, the polycrystalline thin film obtained fall into kesterite crystal phase. This type of crystal was obtained when the CZTS was annealed at 500 °C in H2S/N2 atmosphere. The value of optical band gap energy for the CZTS thin film was 2.2 eV with the film thickness about 1.228–6.366 μm. The sample of CZTS with electrodeposition time of 45 minutes and annealing temperature of 500 °C showed the best result and in conformity with absorber layers criteria for solar cells.
Keyword: semiconductor, ITO glass, CZTS thin film, electrodeposition