A Japanese coast guard vessel left a southern port on yesterday to take part in a joint marine survey with South Korea in waters claimed by both countries, Japan's coast guard said.
The joint survey that will run from Oct. 7 to Oct. 14 is part of efforts to defuse a long-simmering row between Japan and South Korea over the Sea of Japan islets -- called Takeshima in Japanese and Dokdo in Korean.
The coast guard vessel left early yesterday, counting three South Korean researchers among the 30 Japanese staff and crew.
All are charged with determining the level of radioactivity from nuclear waste that was dumped there over many years by the Soviet Union, a Japanese Coast Guard official said on condition of anonymity, citing departmental policy.
A representative from the International Atomic Energy Agency (IAEA) -- the UN's nuclear watchdog -- was also on board.
A South Korean coast guard ship also left that country's southern port of Busan later yesterday.
It was to join the survey, carrying three Japanese researchers, four South Korean experts and an IAEA official, said Suh Young-sang, an official with South Korea's National Fisheries Research and Development Institute.
The two survey vessels will separately collect seawater and soil samples from six spots, including three near the islets and exchange data and analysis afterward, the official said.
It would take approximately eight months to complete a report based on the findings of the survey, he said.
South Korea and Japan separately conducted a similar survey in 1994-1995, with the cooperation of Russia and the IAEA.
From the 1950s to the 1990s, the Soviet Union dumped radioactive waste off its eastern port of Vladivostok, according to news reports, which did not say what the waste consisted of.
In April, South Korea dispatched over 20 gunboats to fend off an attempt by Japan to survey the same waters.
South Korea views such surveys as efforts to bolster Tokyo's territorial claims. Japan eventually canceled the survey.
Seoul and Tokyo have long been at odds over ownership of the rocky outcroppings, which are effectively controlled by Seoul.
The area surrounding the contested islets is believed to contain an abundance of fish and possibly other undersea resources.