Gustiarisanie, Arinie2013-05-302013-05-302013-05-30sumarnihttp://repository.unri.ac.id:80/handle/123456789/3513A research aims was to determine the water quality and to know how condition of phytoplankton in coastal areas Meral district Karimun Regency Kepulauan Riau Province was conducted in January-February 2013. The method used in research is a survey method. Phytoplankton species were found during the research at high tide is class Bacillariophyceae 18 species, Chlorophyceae has 4 types of classes and Dinophyceae has 2 types of classes. While at low tide the amount of phytoplankton of the class Bacillariophyceae is 13 species, Chlorophyceae has 3 types of classes and Dinophyceae has 1 types of classes. The abundance of phytoplankton at high tide range 175-276 cells / l, the diversity index (H ') ranged from 2.50 to 2.99, dominance index (C) ranged from 0.17 to 0 , 22, and index equitability (E) ranged from 0.67 to 0.96. While at low tide the abundance of phytoplankton ranged from 165-243 cells / l, the diversity index (H ') ranged from 2.31 to 2.66, the average dominance index (C) ranged from 0.20 - 0.23, the average value of uniformity (E) ranged from 0.50 to 0.75. From the condition of marine phytoplankton in coastal areas District Meral based on the value of diversity index (H '), dominance (C), and Equitability (E), while waters quality of high tide and lows including a lightly polluted waters, there are activities such as Boat harbour, recreation beach, sea sands dredging and settlements.otherPhytoplanktoncoastal areasMeral districtstudent Paper Post Degree