As a consequence of the magnitude 9.0 earthquake occurred  about 130 km off the Pacific coast of  Japan’s main island Honshu and subsequent tsunami hitting the east coast of Japan on 11 March 2011 the Fukushima Nuclear Power Plants (NPPs) were severely damaged and radioactive material was released to the atmosphere as well as to the ocean.


  To assess radiologic consequences of releases of radioactivity due to global fallout as well as FDNPP accident a Northwestern Pacific development of a compartment model based on POSEIDON-R was initiated from 2012. The model initially used a pelagic fool-chain which consists of phytoplankton zooplankton, Crustacean, Mollusk, non-piscivorous fish, piscivorous fish and Algae.


  Validation of the pelagic food-chain model showed that the benthic food chain plays an important role as the sea water contamination is reduced, We have been currently extending the dynamic biota model with pelagic and benthic food-chains as shown below.