World Notes HIGH SEAS

When Soviet patrol boats seized a fleet of North Korean fishing vessels operating in the restricted northern Pacific early last month, the Soviets themselves were caught by surprise. The twelve ships flying North Korean flags in fact belonged to Japan, and most of the crewmen under arrest were Japanese.

Moscow and Tokyo have an agreement that limits the annual catch Japan can take from those waters. According to Japanese investigators, the Shoho Fisheries Co. struck a deal with a North Korean fishing outfit to lease Japanese boats and market the catch, rigging the ships with Korean flags to circumvent the Japanese quota.

Soviet fisheries officials denounced the scheme as "malicious poaching." But neither Japan nor the Soviet Union wants to turn the case into a major issue while they try to improve relations. Soviet authorities have informally indicated that they will soon release most of the 169 fishermen detained at Shikotan Island.