Low levels of nuclear radiation from the Fukushima plant in Japan have shown up in bluefin tuna nearly 6,000 miles away, off the coast of California. It has been revealed that the 15 fish were caught off the coast of San Diego in August 2011, about 4 months after a tsunami destroyed the Fukushima plant, releasing deadly chemicals into the water.
The fish carried the chemicals considerably quicker than wind or water could have. It took months longer for debris from the plant to start showing up in waters of the U.S. Pacific Northwest and coast of Alaska.
In the 15 tuna tested, trace amounts of cesium-134 and cesium-137 were detected. According to research published in the journal Proceedings of the National Academy of Sciences, the small amounts are not thought to be damaging if consumed by humans. Lead author Daniel Madigan of Stanford University’s Hopkins Marine Station noted that the levels of radioactive materials in the fish were considerably lower than current Japanese safety limits.
Cesium-137 was present in the eastern Pacific region before the Fukushima disaster in April 2011. Cesium-134, however, is produced by human activity and was not present prior to the tsunami hitting the plant.
Since Cesium disperses through water rather than sinking to the bottom, fish easily swim right through it, ingesting it through their gills and by eating plants and other organisms that have already been affected.
Bluefin tuna originate in the western Pacific off the coast of the Philippines and Japan, and some migrate to the east California coast, where a more abundant food supply is available. Judging by the size of the fish, averaging about 15 pounds, researchers concluded they were still young and had likely headed toward California about a month after the accident occurred. As the fish grow, they will excrete Cesium and it will dilute in their bodies, becoming much less potent.
As regular readers of The9Billion will know, Bluefin tuna are rapidly declining and shouldn’t be consumed anyway, even though they are. They’re known for their tender, fatty texture and are popular in sushi restaurants. Maybe now that they’re infected with radiation, however small, they will suffer less as a result of overfishing and plump up their population a bit.
Image CC licensed by Masayoshi Sekimura: Bluefin tuna