Questions and answers on fishery products(Inspections on Radioactive Materials)

A. The Radioactive materials released into the sea are carried by the ocean currents, while being diluted with enormous amount of seawater, and eventually settle on the sea bottom. 

Ministry of Education, Culture, Sports, Science and Technology (MEXT) and Tokyo Electric Power Company (TEPCO) have been monitoring the concentration of radioactive materials in the seawater and sea bottom soil around and offshore the Fukushima Daiichi Nuclear Power Plant. The results of the monitoring have shown that the concentration of radioactive materials in the seawater is on a downward trend. The trend of radioactivity level will be kept under close monitoring to determine its impacts on fishery products. 

A. Radioactive materials may fall into freshwater environments such as lakes and rivers directly from the atmosphere.  Further, radioactive materials once fallen on adjacent mountains and lands may be brought into the freshwater environments by rainwater inflow and through groundwater.

As of 9 March, radioactivity level exceeding the Provisional Regulation Value has been detected in ayu sweetfish, land-locked salmon, Japanese dace, Japanese smelt, whitespotted char and farmed willow gudgeon. 

Inspections of freshwater fishery products will be continued at a sufficient scale.

A. In accordance with the “Basic Policy for Inspections on Radioactive Materials in Fishery Products” established by the Fisheries Agency, sampling and inspections are being conducted for fish species living at surface, middle column and bottom of the sea on a weekly basis, at the major fishing ports in Fukushima and neighboring prefectures.

A.  Fish bodies gradually excrete radioactive materials that have been taken in the bodies from seawater and feed, as in the case of potassium and other non-radioactive minerals. Previous studies show that concentration of radioactive cesium in marine fish can rise up to 5-100times higher than that in surrounding seawater, partly because of the effect of food chain. Cesium concentration in fish bodies corresponds to that in surrounding seawater. When concentration in surrounding seawater is at a low level, cesium concentrated in fish bodies is gradually excreted, and decreased by half within around fifty days. Monitoring on concentration of radioactive materials in seawater is equally important to inspections on radioactive materials contained in fishery products. 

For freshwater fish, it is known that the excretion of radioactive materials takes longer time than marine fish. Inspections of freshwater fishery products will be continued at a sufficient scale.

A. Inspections on radioactive materials will be continued for a wide range of marine species, including demersal and benthic species such as flounders, cod, shellfish, sea cucumber and shrimps. In addition, careful monitoring of the results of the inspections on bottom seawater and soil will be continued.

A. Inspections on radioactive materials have been conducted for a wide range of fishery products mainly in nine (9)prefectures, from Hokkaido to Kanagawa. As of 9 March, 7348 samples have been inspected, and radioactivity exceeding the Provisional Regulation Value has been detected in the following species:

For these fish species, either distribution is restricted in accordance with the instruction by the Government of Japan (e.g. Japanese sandlance taken offshore Fukushima Prefecture, and wild land-locked salmon taken in certain parts of Fukushima Prefecture), or fishing activities are restricted in accordance with the official requests made by the prefectural governments. 

 In addition there are no operations of any coastal and trawl fisheries in the sea area off Fukushima Prefecture currently.

A. Sampling inspections will be continued at the main landing ports on a weekly basis for migratory fish species such as skipjack tuna, chub mackerel and Pacific saury that migrate widely, including through the sea area offshore Fukushima Prefecture.  The results will be announced in a prompt manner.

When it is expected that such species migrate offshore Fukushima Prefecture, sampling by a research fishing vessel should be conducted prior to commercial operations. Commercial operations will be allowed only after the result of the analysis is confirmed to be below the Provisional Regulation Value. Further, inspections continue to be conducted once a week at the main landing ports after resuming fisheries operations in order to confirm safety of fishery products.

A. As there are no fishery operations currently in the sea area near the Fukushima Daiichi Nuclear Plant of Tokyo Electric Power Company, no fishery products from this area are distributed to the markets. 

With regard to the sea area offshore adjacent prefectures of Fukushima, research sampling should be conducted prior to commercial operations. Commercial operations will be allowed only after the result of the analysis is confirmed to be below the Provisional Regulation Value. Further, inspections continue to be conducted once a week at the main landing ports after resuming fisheries operations in order to confirm safety of fishery products.