Japan: High radioactive cesium concentrations found in plankton off Fukushima shores

From multiple news sources in Japan today:

"Researchers from Tokyo University of Marine Science and Technology collected plankton in waters up to 60 kilometers from the coast of Iwaki City in July. They found 669 becquerels per kilogram of radioactive cesium in animal plankton from waters 3 kilometers offshore."

Details and video at NHK WORLD English.

This is worrisome for many reasons, one of which is that plankton is a primary food for many fish that people in Japan consume. There is concern that this contamination will travel up the food chain.