Species Composition and Abundance of Ichthyol-Plankton in Han River Estuary in Spring and Summer of 2017~2019

This study was conducted to provide the basic information on environment effects on appearance of ichthyoplankton in the Han River Estuary in spring and summer from 2017 to 2019. Data were obtained from the database of "Coastal ecosystem" in "National Survey of Marine Ecosystem". Species composition showed Gobiidae spp. ichthyoplankton species, comprised of 51.4% of total abundance. And second dominated species was Callionymidae sp. With 25.3% of total abundance. Yearly, in spring, Pleuronectidae sp. was abundant in 2017, Liparis tanakae was abundant in 2018, and Gobiidae spp. was abundant in 2019. In Summer, Gobiidae spp. and Callionymidae sp. were abundant in 2018 comprised of 49.5% and 38.6% respectively, and Gobiidae spp. was predominant (84.1%) in 2019. In summer of 2017, discharge of Han River was sufficient to alter salinity in the study area causing low distribution of ichthyolplankton. Cluster analysis result show a composition differentiated between spring and summer. However, the similarity was lower than 20% showing variety of species composition among year in seasons.