Some of the significant fish that are found here include cod, croakers, goby, eel, Japanese mackerel, lizardfish, Pacific herring, sea bream, etc.
I already know where they get fishes for sushi. 
Are there beach for tourists there?
The coasts of the Yellow Sea are very densely populated, at approximately 250 inhabitants per square kilometer (650/sq mi). The sea waters had been used for fishing by the Chinese, Korean and Japanese ships for centuries.