To examine species composition, abundance and biomass of fishes in the northwestern East Sea of Russian EEZ, trawl survey were conducted at 31 sampling stations from 2006 to 2008. Also, trawl survey were conducted at 21 sampling stations in the southwestern East Sea of Korean EEZ from 2006 to 2008. A total of 67 fishes were collected in the northwestern East Sea of Russian EEZ, a total of 39 fishes were collected in the southwestern East Sea of Korean EEZ. Among them, a total of 53 fishes were collected in the northwestern East Sea of Russian EEZ only, and a total of 25 fishes were collected in the southwestern East Sea of Korean EEZ only. Mean abundance per area which caught by trawl survey in the northwestern East Sea ranged from a high of 116,478 inds./km2 in 2008 to a low of 19,737 inds./km2 in 2006. And mean abundance per area in the southwestern East Sea ranged from a high of 89,129 inds./km2 in 2006 to a low of 8,234 inds./km2 in 2008. Mean biomass per area which caught by trawl survey in the northwestern East Sea ranged from a high of 11,333 kg/km2 in 2008 to a low of 2,439 kg/km2 in 2006. And mean biomass per area in the southwestern East Sea ranged from a high of 6,273 kg/km2 in 2006 to a low of 1,062 kg/km2 in 2008. Cluster analysis, based on a Bray–Curtis similarity matrix of fourth root transformed data of number of species and individuals per area, showed division into three different groups by depth in the northwestern and southwestern East Sea.

To examine species composition, abundance and biomass of demersal organisms in the East Sea, bottom trawl survey was conducted at 7 sea areas from 2005 to 2007. A total of 107 species were collected and were composed of 54 fish species, 16 crustacea, and 37 mollusks in the East Sea from 2005 to 2007. Yearly abundance per area which caught by trawl survey in the East Sea from 2005 to 2007 ranged from a high of 292,234inds./km2 in 2005 to a low of 192,092inds./km2 in 2006. The abundance by sea area showed a peak in 76 sea area, and the lowest in 63 sea area. The abundance per area by season showed a peak in summer, and the lowest in spring. The most dominant species in abundance were Clupea pallasii, Neocrangon communis, Chionoecetes opilio. Yearly biomass per area which caught by trawl survey in the East Sea from 2005 to 2007 ranged from a high of 10,322kg/km2 in 2006 to a low of 7,096kg/km2 in 2005. The most dominant species in biomass were Chionoecetes opilio, Clupea pallasii, Dasycottus setiger. The biomass by sea area also showed a peak in 76 sea area, and the lowest in 93 sea area. The abundance by season also showed a peak in summer, and the lowest in spring. As a result of cluster analysis, demersal organisms community of 76 sea area showed a large difference with other sea area, and that of summer showed a large difference with other season.