On March 11th of 2011, the Tohoku earthquake and the tsunami that followed it led to the Fukushima Daiichi nuclear disaster. Approximately 25,000 people were killed and thousands more were injured in that disaster; many lost their homes and businesses as well. Though the tsunami and nuclear meltdown happened comparatively long ago, life in the Fukushima prefecture is still not back to normal – for people, or for fish. In fact, water off Fukushima is still testing at levels 7.5 million times more radioactive than the Japanese legal limit.
Seafood Safety and the Fukushima Nuclear Disaster
In the wake of the Fukushima nuclear disaster, fish exports from affected waters were halted since seawater was heavily irradiated; to date, an estimated three million gallons of heavily contaminated water has made its way into the ocean. Despite cleanup and repair efforts, radiated water continues to make its way into the Pacific near the Fukushima Daiichi power plant site as the reactors are still overheating and must be cooled with water to prevent a worse disaster from occuring. Now, fisheries experts are questioning whether migratory tuna – which make their way into North American waters – are safe for people to eat.
Japan’s nuclear crisis might seem as if it’s an ocean away from the North American continent, but in reality, tuna leave Japan each spring, arriving in the Pacific Northwest each summer. These large, slow-growing fish have been exposed to some of the world’s most toxic water; the American Fishermen’s Research Foundation is expressing grave concern over the safety of tuna caught annually off the coasts of Oregon and Washington states. Scientists working with the foundation are urging US government officials to test fish prior to allowing tuna products derived from affected fisheries to be released onto the market.
Tiny fish living in the waters off Fukushima have turned up with unsafe levels of Cesium 137 and Iodine 131. Cesium 137 is a radioactive isotope with a half life of about 30.17 years; in March of 2013, fish tested for this substance contained 7,400 times the Japanese government’s limit for safe human consumption. Iodine 131 is also known as radioiodine; it is noted for causing cellular death and mutations, and it has been linked to increased incidents of thyroid cancers.
Scientists who have studied the effects of radiation on fish are concerned because Cesium 137 accumulates in muscle tissue – the portion of the fish that is most often consumed. In addition, they are concerned because fish of different sizes react to exposure to Cesium and other radioactive substances in different ways. Some fish are particularly prone to genetic damage, and some sustain severe reproductive damage, which could potentially affect tuna numbers years from now.
Japan’s fisheries scientists believe affected albacore tuna will become less radioactive over time, saying that the radioactive isotopes the fish have been exposed to will dissipate over time. Though Japan’s fisheries have suffered tremendously in the wake of the Fukushima Daiichi disaster, the US Food and Drug Administration says fish in the US food supply are safe to eat.