Diversity of Epipelic Diatom in The Waters of Tanjung Pinang City Province of Riau Islands

Degradation indicator of water quality can be seen from changes in water quality parameters. Diatoms are one organism that can be used as an environmental bioindicator. Diatoms are the primary producers in waters so they have a very important role in the food chain. Data was collected in situ in the Tanjung Unggat waters of Tanjung Pinang City. The method used in this study is a survey method, where data is obtained through observations and measurements in the field. The samples taken are then taken to the laboratory for analysis. Epiphyte diatom samples were taken from 4 stations with different activities. Based on observations of the identification of diatom epipelic that has been done, found 22 diatom genera, namely, Pleurosigma sp. , Navicula sp. , Diploneis sp. , Achnanthes sp. , Synedra sp. , Nitzschia sp. , Gyrosigma sp. , Surirella sp. , Coscinodiscus sp. , Thallasiossira sp. , Thallasionema sp. , Pinnularia sp. , Plagiotropis sp. , Halamphora sp. , Biddulphia sp. , Melosira sp. , Chaetoceros sp. , Triceratium sp. , Isthmia sp. , Licmopora sp., and Rhizosolenia sp. The abundance of diatoms in epipelic samples, which ranged from 905277 - 599530 ind / cm 2 . The structure of Epipelic Diatom Community average diversity index ranges from 3.72 to 4.65 and the dominance index value ranges from 1.09 to 1.46 and the uniformity index value ranges from 0.95 to 1.21.Then based on the results of the Storet Index classification, getting a score of -52.75 on 8 parameters tested. This scoring means that around the category of Class D Tanjung Pinang Coastal waters with a score ≥ -31 are classified as Heavy Polluted waters with the determination of the status of the waters quality is limited to 8 parameters tested.