From 2003 to 2016, 1,649 samples were collected, covering both the time and space of Gulf Tonkin. The results have identified groups seasonal dominant fish eggs larvae: Seven species in Spring, nine Summer, six Autumn, four Winter. index (Yi) ranges from 0.02 0.26 depending on group each season year, highest Goby - Gobiidae (Yi = 0.26) achieved followed by Herringgroup Clupeidae reaches Yi 0.20...