5 years after Fukushima, Pacific Ocean radiation normal again

4 Jul 2016

It’s been five years since Fukushima became the latest byword for a nuclear disaster, but how much radiation remains in the Pacific Ocean after so many years?

The 9.0 magnitude earthquake that occurred off the coast of Japan was not only one of the largest ever recorded, but one which was heralded as having a detrimental effect on the planet itself following the meltdown at the Fukushima nuclear power plant.

As the tsunami crippled the plant’s ability to cool itself, resulting in the meltdown, one of the largest dumps of nuclear waste in the world’s oceans occurred, causing concerns that nuclear seas would not only kill natural life in the Pacific Ocean but spread it to surrounding shores.

The Japanese government immediately began restrictions of certain foodstuffs in the region in the weeks and months following contamination, with reports of high levels of radiation detected off the US coast in 2015.

Now, five years later, in 2016, a review of the Pacific Ocean by the Scientific Committee on Oceanic Research analysed 20 studies on radiation levels in the ocean and it has shown that they are rapidly returning to normal levels.

Less than 1pc above limit

Citing one example, co-author of the review, Pere Masque, said: “As an example, in 2011, about half of fish samples in coastal waters off Fukushima contained unsafe levels of radioactive material.

“However, by 2015, that number had dropped to less than 1pc above the limit.”

That’s not to say all is rosy in Fukushima, however, as this same review has analysed data that shows that the seafloor and harbour near the plant remains highly contaminated, with Masque admitting that measurements will need to continue there for many years to come.

This was determined following analysis of caesium levels along the coasts of the Pacific and North America as the nuclear power by-product is an effective way of measuring radiation levels in water.

Mt Bandai and Inawashiro Lake, Fukushima image via Shutterstock

Colm Gorey was a senior journalist with Silicon Republic