Judul: Coral Reef Health Index in East Coastal Waters of Kei Besar Island, Southeast Maluku
Abstrak: Kei Besar Island has the potential of coral reef resources that have not been explored and utilized optimally. The lives of the people of Kei Besar Island depend on marine resources, especially from coral reef ecosystems. This causes the need for management of coral reef ecosystems by looking at the health conditions of coral reefs. The purpose of this study was to examine the distribution of the reef health index in the eastern coastal waters of Kei Besar Island. Data collection was carried out on 3-18 November 2018 in the coastal waters of East Kei Besar with 6 location points, namely Ohoifau, Hollat, Fako, Ngufit Bawah, Weduar, and Kilwait at a depth of 3 meters using the Point Intercept Transect (PIT) and Underwater Visual Census methods. (UVC). The results showed that the East coast of Kei Besar has a fairly well-maintained condition of the coral reef ecosystem. This can be seen from the condition of coral reef cover (hard coral) which is classified as good. The distribution of coral reef health index values in the coastal waters of East Kei Besar shows that the waters are classified as good at a value of 5-6. The Hollat location has the lowest coral health value because at this location it is affected by a decrease in ship anchors and high algal cover. This research is expected to be useful in providing information to the local community and government in an effort to improve coral reef resources., Pulau Kei Besar memiliki potensi sumberdaya terumbu karang yang belum tereksplorasi dan dimanfaatkan dengan optimal. Kehidupan masyarakat Pulau Kei Besar bergantung dengan sumberdaya laut terutama dari ekosistem terumbu karang. Hal ini menyebabkan perlu adanya pengelolaan ekositem terumbu karang dengan melihat kondisi kesehatan terumbu karang. Tujuan penelitian ini adalah untuk melihat persebaran indeks kesehatan terumbu di perairan pesisir Timur Pulau Kei Besar. Pengambilan data dilaksanakan pada tanggal 3 – 18 November 2018 di perairan pesisir Timur Kei Besar dengan 6 titik lokasi yaitu Ohoifau, Hollat, Fako, Ngufit bawah, Weduar, dan Kilwait pada kedalaman 3 meter menggunakan metode Point Intercept Transect (PIT) dan Underwater Visual Census (UVC). Hasil penelitian menunjukkan pesisir Timur Kei Besar memiliki kondisi ekosistem terumbu karang yang cukup terjaga. Hal ini terlihat dari kondisi tutupan terumbu karang (hard coral) tergolong baik. Sebaran nilai indeks kesehatan terumbu karang di perairan pesisir Timur Kei Besar menunjukkan bahwa perairan tersebut tergolong baik berada pada nilai 5-6. Lokasi Hollat memiliki nilai kesehatan karang terendah karena pada lokasi ini dipengaruhi oleh penurunan jangkar kapal dan tingginya tutupan alga. Penelitian ini diharapkan dapat bermanfaat dalam memberikan informasi kepada masyarakat dan pemerintah setempat dalam upaya meningkatkan sumberdaya terumbu karang.
Keyword: coral reef health index, coral reefs, point intercept transect, underwater visual census

Judul: Benthic and Nektonic Complexity in Kei Besar Coral Reef Ecosystem, Southeast Maluku
Abstrak: Penelitian ini dilakukan untuk menentukan kondisi ekosistem terumbu karang di perairan Kei Besar, dengan mengukur komposisi dan kompleksitas habitat terumbu karang terhadap kelimpahan dan keanekaragaman spesies ikan terumbu. Penelitian dilakukan dengan pengamatan bawah air menggunakan Point Intercept Transect (PIT), Belt Transect dan estimasi visual kompleksitas struktural habitat di sembilan titik pengamatan pesisir timur Kei Besar. Hasil menunjukkan persen tutupan karang yang tinggi (hingga 75%) dan kemungkinan yang rendah untuk terjadi pergeseran dominansi ke tutupan organisme bentik lain seperti alga, karang lunak, atau spons. Tidak diperoleh hubungan yang spesifik (multikorelasi) antara kekayaan jenis dan kelimpahan ikan dengan sejumlah variabel komunitas bentik terumbu, terutama tutupan karang keras hidup dan kekayaan genus karang. Satu-satunya variabel bentik yang didapati berpengaruh positif terhadap komunitas ikan adalah kompleksitas habitat dasar terumbu karang., This research was conducted to determine the condition of coral reef ecosystems in Kei Besar, by measuring the composition and complexity of coral reef habitats, abundance and diversity of reef fish species. It was carried out using underwater observation using Point Intercept Transect (PIT), Belt Transect and visual estimation of the structural complexity of the habitat at nine observation points along the eastern coast of Kei Besar. The results showed a high percentage of coral cover (up to 75%) and low probability of a shift in dominance of other benthic organisms such as algae, soft corals, or sponges. No specific relationship (multicorrelation) was found between species richness and fish abundance with a number of reef benthic community variables, especially live hard coral cover and coral genera richness. The only benthic variable that was found to have a positive effect on the fish community was the complexity of the coral reef base habitat.
Keyword: organisme bentik, ikan terumbu, kompleksitas habitat, komunitas, ekosistem terumbu karang, benthic organism, reef fish, habitat complexity, communities, coral reef ecosystem

Judul: Grup dan Homomorfisma Grup pada Rubik Revenge
Abstrak: Rubik cube is a kind of puzzle game. A player must arrange rubik sides, which have been disordered, back to the position where every side has the same colour. This paper does not focus on the settlement solution, but instead on proving the existence of a group homomorphism between rubik movement group and S96 symmetric permutation group in rubik revenge. Firstly, it has been proved that rubik movement set is a group. Then, it also has been proved that the M set, which contains numeric labels of 1 until 96 in cubinos sides, is S96 symmetric permutation group.
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