Phytoplankton composition and diversity of Taninthayi coastal waters, Myanmar

Abstract

Water samples collected by R/V DR. FRIDTJOF NANSEN during Myanmar ecosystem survey 2018 were analyzed to determine the species composition and distribution of phytoplankton. A total of one hundred and eighty-eight taxa of marine phytoplankton were identified and comprised of 116 taxa of diatoms, 67 taxa of dinoflagellates, 2 taxa of silicoflagellates and 3 taxa of cyanobacteria. Phytoplankton community was dominated by diatoms with 61.7% of total samples, followed by 35.6% of dinoflagellates. Species composition and abundance was found to be highest at station 799 with 90 species (2147no/m3) and lowest at station 846 with 36 species (673no/m3). The index values encountered from Taninthayi coastal waters ranged between 3.97 and 3.31 for species diversity index (H’), between 0.94 and 0.05 for evenness index (E’) and between 13.76 and 6.69 for species richness index (D’). High diversity index values (H’, E’, and D’) were recorded at the nearshore stations. The density and diversity of phytoplankton were positively correlated with the nutrients (chlorophyll a, nitrate, nitrite, silicate, phosphate) and negatively correlated with the temperature and salinity.