It might seem straight out of science fiction, but this story is real – radioactive tuna could be swimming in an ocean near you.
A new study found that after last spring’s Fukushima nuclear accident, Pacific Bluefin tuna caught off of San Diego appear to have been contaminated by radioactive materials from last spring’s nuclear accident in Japan.
The March 2011 earthquake and subsequent tsunami led to the meltdown of the Fukushima nuclear plant in central Japan. Even now, the only way to enter the zone 20 kilometers around the plant is with special government permission. After the accident, tests showed that concentrations of radioactive Cesium in coastal waters increased up to 10,000-fold.
This study, published in the Proceedings of the National Academy of Sciences, found the same radioactive Cesium in 15 Bluefin tuna specimens caught outside of San Diego. The fish tested showed a 10-fold increase from normal Cesium concentrations, well below the safety limit established by Japanese Ministry of Agriculture, Forestry, and Fishes.
Bluefin are a highly migratory species – they spawn in the West Pacific near Japan, then, once they have matured, may travel more than 9,000 miles to the East Pacific and the California coast. They’re such strong swimmers that the trip only takes a few months.
During the course of this trip, the radioactive concentration fell as the fish grew and the Cesium decayed. If they had tested tuna from Japan, the radiation would be expected to be up to 15 times more concentrated, according to Daniel Madigan, Zofia Baumann, and Nicholas Fisher, the co-authors of the study.
Monterey Bay Aquarium’s Seafood Watch already lists bluefin as a species to avoid due to severe overfishing and high mercury levels. They’re highly valued as sushi fish, which has led to a steep decline in their populations in both the Atlantic and Pacific oceans. Bluefin tuna are slow to mature, and are often caught before they have a chance to reproduce. Oceana is currently working to protect bluefin tuna from overfishing.
The Fukushima nuclear disaster, sparked by the earthquake and tsunami that devastated Japan last March, has led the Japanese government to embrace a safer energy source: offshore wind.
Japan seeks to expand its wind energy capacity and compete with European markets in the brand new field of floating offshore wind technology. The country plans to build a pilot floating wind farm with six 2-Megawatt turbines, and then scale up to 80 floating turbines off the Fukushima coast by 2020.
While offshore wind has begun to be used in Europe, to date, it has been dependent on shallow enough water to stabilize the foundation. There is currently an international race to develop floating offshore wind farms, which are the next big step in offshore wind energy as they will allow for offshore wind development even in deeper water.
Floating offshore wind designs are being field tested in the North Sea and Portugal. (Check out this video describing how one type of floating wind turbine is designed and deployed.) Floating wind farms consist of large floating structures that support a spinning turbine, the base of which can be tethered to the ocean floor.
It uses a ballast system to transfer water between pillars to keep the platform stable even in very high seas. The floating farms are assembled on land and then can be towed out to sea to be placed in deeper water locations that have stronger and steadier winds. The ability to place offshore wind farms into deeper waters along with their lack of concrete bases and increased mobility reduces their environmental impact while increasing their production of clean energy.
Japan has responded to the Fukushima disaster in the way that the U.S. should respond to the Gulf of Mexico oil spill disaster – by aggressively pursuing safer, more environmentally friendly energy sources that will allow us to phase out the older and more dangerous ones.