Description of Some Microalgae Isolates Captured from Sumatra Island, Indonesia

Microalgae as phytoplankton become the considerable attention object because of their potential in various application. Microalgae can be discovered in various ecosystems and growing in all environmental conditions. The purpose of this study was to identify the genus and abudance of microalgae in some of the coastal area of Sumatera Island, Indonesia. This study was conducted in August until September 2022. The method used is descriptive quantitative by exploration and microalgae calculations. The calculations based on Shannon-Wiener such as abundance, relative abundance, diversity index, uniformity index and dominance index. The sampling area selected was carried out in Suak Ribee Beach (Aceh), Gandoriah Beach (Padang) and Lengkuas Island (Belitung). The sampling method used the random sampling method by horizontal sampling. Statistical analysed is NMDS (non metric multidimensional scaling). The results obtained were 4 class, namely Bachillariophyceae, Chlorophyceae, Cyanophyceae, Fragilariophyceae and 21 genera, namely Achnanthes, Anabaena, Aphanocapsa, Bacillaria, Chalamydomonas, Chroococcus, Cocconeis, Diploneis, Encynopsis, Eudorina, Eupodiscus, Fragilaria, Gyrosigma, Hyalodiscus, Navicula, Nitzschia, Oocytis, Parlibellus, Peronia, Stauroneis and Ulothrix. Microalgae was dominated by group of Bachillariophyceae (76%). The abudance of microalgae obtained range from 11.117 - 36.442 cells/L. The results showed that the diversity index value was moderate (1,46), low dominance (0,17) and moderate uniformity (0,48).