Judul: The Approximation of Coral Reef Ecosystem Quality in The Seribu Islands Using Benthic Foraminifera Proportion as Bioindicator
Abstrak: Coral reef ecosystem is one of mega biodiversity environments with the highest ecological pressure especially caused by human activities. Local impact like nutrification will decrease water quality and the ecosystem. Benthic foraminifera as bioindicator can be used as early monitoring tool to observe the changes in reef ecosystems. Therefore the aims of this study were to investigate the distribution of benthic foraminifera in reef ecosystem and determine the relationship between coral ecosystems with FORAM Index as tool for benthic foraminifera to asses waters quality. Eleven stations from Karang Bongkok, Pramuka, and Onrust on Seribu Island were used for this study. Nutrient and physical parameters were measured in situ and in the laboratory. The foraminifera was separated from sediment and indentified by binocular microscope. The foraminifera then classified by functional group and calculated by FORAM Index formula (FI). The range of FI was from 3,4-8,2, which indicated marginal to suitable environment for reef development. The modification of FI (FIm) showed that the range from 1,2-5,2 where there were unsuitable environment for reef growth in Onrust Island. The results showed that Calcarina and Amphistegina are indicators of reef health ecosystem. Nevertheless, FORAM Index can be applied in Indonesia waters with some modification with considering the preference of the habitat.
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Judul: Efektivitas Terumbu Buatan Berbahan Dasar Tempurung Kelapa sebagai Fish Aggregating Device di Pulau Pramuka Kepulauan Seribu
Abstrak: Artificial reefs is an artificial habitat which is created to resemble the characteristics of natural reefs to improve the community of coral reefs that have been damaged in natural waters ecosystem. The effectiveness of artificial reefs made of coconut shell is observed during the period of March 2012 - May 2012 in the waters of Pramuka island, Kepulauan Seribu, Jakarta. The method used experimental method, where bubu tambun is used to capture the specimen that will be analyze for it’s level of gonad maturity. The observations is done with the visual census method with 2 areas i.e. 1 meter and 2 meter that would later be analyzed for it’s index of diversity (H’), index homogeneity (E) and the dominance index (C) at the artificial reefs site. The results showed that 10 family with 13 species are dominant to stay while in the natural coral reef consists of 8 family with 25 described species. The result of fishing capture, it consist of 10 family (Pomacentridae, Balistidae, Chaetodontidae, Holocent, Labridae, Scaridae, Siganidae, Xanthidae, Muraenidae). Gonado Stomato Index (GSI) of fishing capture are GSI I (46%); GSI II (28%); GSI III (22%) and GSI IV (4%). Artificial reefs with 1 meter areas has a range of diversity index between 1.68 -2.5; and the uniformity index ranged between 0,68-1.07 and dominance index 0.11-0.16. Artificial reefs with 2 meters areas has a range of diversity index between 1,79 – 2,15; range of uniformity index 0.59-0.90 and the index of the dominance of 0.09- 0.16.
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Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf