The Distribution and Diversity of Dinoflagellate Cysts in Sediments of Gwatar Bay (Northeast Gulf of Oman)

Abstract

Most dinoflagellate produce resting cysts during their sexual lifecycle as well as under unfavorable environmental conditions and from water column settle in the sediments substratum. The evaluation of diversity and distribution of dinoflagellate cysts is very important in environmental studies, because cysts act as seed in sea bed that can cause red tide with excystment. This study was performed to determine the diversity and distribution of dinoflagellate cysts in the sediments of Gwatar Bay in 2013 by sediments sampling from five stations. Sediment sampling was made by Ekman grab with covering area of 0.225 square meters with three replicates at each station in two seasons before and after the monsoon. In total of sampling 16 samples in species level belonging to 9 genera of dinoflagellate cysts were identified. The highest and lowest abundances are related to the genus Protoperidinium (52%) and the genus Zygabikodinium (1%), respectively. The results showed the average dinoflagellate cysts diversity from 2.22 before monsoon have decreased to 2.06 after monsoon.