<![CDATA[ABSTRAKPerairan Rebo yang berada di Desa Rebo Kabupaten Bangka Provinsi Kepulauan Bangka Belitung memiliki populasi terumbu karang di daerah Karang Melantut, namun daerah ini mengalami kerusakan dari kegiatan penambangan timah lepas pantai dan TI apung yang menghasilkan limbah berupa tailing (lumpur). Akibat dari pengendapan lumpur berdampak buruk terhadap ekosistem terumbu karang salah satunya pertumbuhan alga yang bersimbiosis dengan karang yaitu zooxanthellae. Tujuan penelitian yaitu mengetahui perbedaan densitas zooxanthellae pada karang keras dengan jenis yang berbeda. Penelitian dilakukan pada Bulan Agustus tahun 2022, dengan mengambil tiga jenis karang yaitu Lobophyllia corimbosa, Acropora kimbeensis, dan Acropora nobilis. Metode penelitian yaitu melakukan isolasi sel zooxanthellae dengan menyemprotkan air laut tersaring pada fragmen karang menggunakan water flosser hingga sel terlepas dari jaringan karang. Larutan sel zooxanthellae diawetkan dalam botol sampel yang diteteskan formalin 4% sebayak lima tetes dan diamati di bawah mikroskop. Rata-rata densitas zooxanthellae dihitung menggunakan Microsoft exel yaitu Lobophyllia corimbose 1507 sel/cm², Acropora kimbeensis 4134 sel/cm², dan Acropora nobilis rata-rata 2294 sel/cm². Hasil pengolahan data menggunakan statistik analisis varian (ANOVA) menunjukkan adanya perbedaan nyata densitas zooxanthellae pada ketiga jenis karang dengan nilai signifikan 0,05. Hasil dari uji ANOVA dan tukey test, mendapatkan nilai F hitung 67.413 dan memperoler F tabel sebesar 3,13 sehingga keputusan yang diterima adalah H1, yaitu adanya perbedaan densitas zooxanthellae pada tiga jenis karang. Adanya perbedaaan densitas zooxanthellae pada ketiga jenis karang disebabkan oleh perbedaan lifeform karang. Perbedaan lifeform karang dipengaruhi oleh suhu, kedalaman dan tingkat ekstrim suatu perairan. Kata Kunci: zooxanthellae; densitas; kabupaten bangka.ABSTRACTRebo Villagein Bangka Regency, Bangka Belitung Islands Province has high population of coral reefs in Karang Melantut area, but has suffered damage from offshore tand anshore in mining activities which produce waste in the from of sludge. The consequences of sludge deposition can have a negative impact on coral reef ecosystems, especially the relationship of corals with the symbiotic algae (zooxanthellae). The aim of this research is to analysis of differences in density, size and mitotic index of zooxanthellae. The research was conducted in August 2022, by taking three types of coral, Lobophyllia corimbosa, Acropora kimbeensis, and Acropora nobilis. The research method is to isolate zooxanthellae cells by spraying filtered seawater on coralfragments using a water flosser until the cels are seperatedfrom the coral. The zooxanthellae cell solution was placed in a sample bottle in which five drops of 4% formalin were added and observed under the microscope. The average density of zooxanthellae was calculated using Microsoft exel, from Lobophyllia corimbosa is 1507 cells/cm², Acropora kimbeensis 4134 cells/cm², and Acropora nobilis an average of 2294 cells/cm². The results of the statistic analisis of variance (ANOVA) showed that there were significant differences zooxanthellae in the three types of coral with a significant value of 0.05. The results of the ANOVA test and Tukey test obtained a calculated F value of 67.413 and obtained an F table of 3.13 so that the decision received was H1, namely that there were differences in zooxanthellae density in the three types of coral. The difference in zooxanthellae density in the three types of coral is caused by differences in coral lifeforms. Differences in coral life forms are influenced by temperature, depth and extreme levels of water.Keywords: Zooxanthellae; Density; regency bangka. ]]>
