11/20/2011, Japan Agency for Marine-Earth Science and Technology announced that in April, Cesium from Fukushima dropped from air to the pacific ocean and fell down deep in the sea attached to dead plankton.
4/18~4/30, Japan Agency for Marine-Earth Science and Technology measured cesium from particles which is made of dead plankton or sand, smaller than 1mm, called “Marine snow”.
It was off shore of Polustrov Kamchatka, where is 2,000 km away from Fukushima and 5,000 meters deep in the sea around Ogasawara islands, where is 1,000 km away from Fukushima.
From the ratio of cesium 134 and 137, they judged it was from Fukushima plants. They have not announced the amount of cesium.
(Source)