Fukushima diary reports, citing TEPCO, that this is a most realistic estimate where free floating material (fish larvae, algae, phytoplankton, zooplankton…) present in the sea water near the damaged Fukushima Daiichi nuclear power station plant could have gone since the earthquake on March 11th.
They warn in capital letters that this is not a representation of the radioactive plume concentration but nothing more and nothing less that their best estimate of where the Fukushima radioactive debris may be in the said months:
However they also say that TEPCO monitoring indicated radiation higher than the legal limit (in Japan?) during the months after the accident. So be warned.