Fish caught off the coast of Japan following the Fukushima nuclear disaster are still contaminated, bringing speculation that leakage from the reactors has not been fully stopped. If true, it could threaten area marine life for decades to come.
A recent article in Science reveals that 40 per cent of bottom-dwelling marine species show cesium-134 and 137 levels above normal.
In examining the data, collected by Japan’s Ministry of Agriculture, Fisheries and Forestry, the article’s author Ken Buesseler, a marine chemist at the Woods Hole Oceanographic Institution in Massachusetts, discovered that the levels of contamination in most fish have not declined a year after the March 2011 tragedy. August samples of bottom feeders had cesium levels some 250 times the level the Japanese government considers safe.
“The numbers aren’t going down. Oceans usually cause the concentrations to decrease if the spigot is turned off,”Buesseler told the Associated Press in an interview. “There has to be somewhere they’re picking up the cesium.”
“Option one is the seafloor is the source of the continued contamination. The other source could be the reactors themselves,” he said.
Radioactive cesium is a human-made radioactive isotope produced through nuclear fission of the element cesium. It has a half-life of 30 years, making it extremely toxic.
Contaminated fish have a huge impact on the Japanese population, as the country ranks highest among per capita consumption of seafood.
Most marine species from the Fukushima coastline are banned from the domestic market and export.
But in July this year, Russia acknowledged that it faced a threat from fish caught off its coast near Japan.