Dinoflagellata Community Structure In The Waters Of Juata Permai Village, Tarakan City

Abstract

Dinoflagellates are a class of phytoplankton and are divided into two groups, namely autotrophs and heterotrophs. This research aims to analyze the structure of the phytoplankton community, especially from the dinoflagellate class, namely in terms of the number of species, and the abundance of dinoflagellates in the waters of Tarakan, Juata Laut Village, Tarakan City. There are 7 types of dinoflagellates found in waters, namely: Ceratium spp., Noctiluca sp., Protoperidinium spp., Prorocentrum spp., Gymnodinium sp., Gonyaulax sp., and Dinophysis sp. This research was conducted for 2 months by using descriptive analysis. The results showed that the index values for diversity, uniformity, and dominance of dinoflagellates ranged from 0.06 to 1.53, uniformity from 0.09 -0.80, and dominance from 0.23 -0.95. The highest diversity index value is at Station 3 of 1.63 and the lowest diversity index is at Station 5 of 0.07, the highest uniformity index value is at Station 3 of 0.90 and the lowest diversity index is at Station 5 of 0.10, while The highest dominance index is at Station 3 of 0.97 and the lowest dominance index is at Station 9 of 0.23. Water quality parameters still show the optimum value with temperatures ranging from 27-30°C, brightness 53-63 cm, salinity 16-2 4 ppt, and Ph 7.2 -7.4. Optimum concentrations of chlorophyll a, b, and c from morning to afternoon with sampling at 08.00 -12.00 with chlorophyll a value of 0.3447 µg.L-1, chlorophyll b 0.2081 µg.L-1 and chlorophyll c 0.03 µg.L-1.

Structure of The Plankton Community In Tanjung Pasir Sea Waters, Tarakan City

“…The calculation formula using SRC is as follows. The uniformity index was calculated using the formula [36] E = H'/Hmax Information: E : uniformity index H' : diversity index Hmax : maximum diversity index (= ln S, where S = Number of species)…”