A domestic marine expert argued Friday that the undersea area around Korea's eastern islands of Dokdo and Ulleungdo creates a rich fishing zone, as it produces more phytoplanktons than other areas in the East Sea.

Dr. Yoo Shin-jae at the Korea Ocean Research and Development Institute said in his latest report that the Ulleung Basin has 20 to 30 percent more phytoplanktons than other East Sea areas, due to upwelling, or the surging of cool and nutrient-rich sea water toward the sea surface.

He said that the upwelling mixes cold water from the deep with nutrient salts which are useful in proliferation of microorganisms, creating a rich fishing zone around the islands.

The research also argued that satellite data shows that the waters off the east coast contain up to ten times as much chlorophyll as Japan's coastal sea.