China’s State Oceanic Administration states on August 15, 2011 that that radiation from Japan’s Fukushima nuclear power plant has spread to the East China Sea, with damaging radioactive cesium-137 and -134, as well as strontium-90 being among the substances found.

http://english.cntv.cn/program/newshour/20110815/104046.shtml
http://economictimes.indiatimes.com/news/international-business/china-says-japanese-n-plant-leak-contaminated-
its-sea-waters/articleshow/9622240.cms