 An intensive naval search by the U.S. with assistance of Japanese and Korean vessels was carried on in a area of the strait just north of Moneron Island.In 1956 the Soviet government proposed that a causeway be built at the Tartar Strait to block cold water from flowing into the Sea of Japan therefore raising the temperature in areas around the Sea of Japan.The Russians claimed it would raise the temperature of the Sea of Japan by an average of 35 °F (19.5 °C).