Greenpeace experts examine fish samples on the Rainbow Warrior to monitor radiation levels as the ship sails up the eastern coast of Japan on her way to Fukushima in May 2011. Jeremy Sutton-Hibbert / Greenpeace.
There have been a number of news stories recently about the radiation escaping into the ocean at the Fukushima Daiichi nuclear power plant that have raised great concern. Some are worried about how escaping radiation may or may not be affecting ocean eco-systems around the world.
Since Greenpeace has been working on the Fukushima nuclear crisis since it first began in March 2011, we can offer some thoughts on peoples concerns.
We have sampled sealife along the Japanese coastline, both from the Rainbow Warrior and in conjunction with local fishermen and Japan's food cooperatives.
You can find some of the results of our independent measurements onour Radiation Surveys Fukushima webpage.
While we dont have a marine biologist on our team, we have a number of radiation specialists whose findings and assessments we share with scientists and academic researchers.
There are many reasons to be concerned about the continuing impacts of the disaster on people and the environment. These include the ongoing leaks of contaminated water from the damaged Fukushima reactors into the ground and ocean, the unresolved issue of how to reliably store huge volumes of contaminated water, as well as the massive amounts of radioactive material produced by the decontamination efforts in FukushimaPrefecture.
Then there is the plight of over 100,000 evacuees. Their lives are in limbo. After nearly three years, they still have not received proper compensation from either the government or the corporations responsible for the accident.
Many people have been exposed to significantly elevated levels of radiation. Thousands of square kilometers have been contaminated and will be for many decades to come by radioactive fallout from the accident.
Then there are the challenges of dismantling the whole crippled nuclear power plant whose melted reactors still have lethally dangerous nuclear fuel inside them.
These alone are enough to conclude that the situation is really,reallybad.
However, there are also stories that exaggerate the risks and create news of potential catastrophies that are well beyond reality. Given that people's trust in public authorities has been shaken (and not without a reason!), one can often find alarming but unconfirmed information on social media.
Most recent have been the stories of rumours about ongoing nuclear reactions inside the crippled Fukushima reactors and vast radioactive contamination of the Pacific Ocean and US West Coast.
We have checked these stories and our conclusion is clear: these are not stories based in fact. For example, while unprecedented amounts of radioactive cesium have ended up in the Pacific Ocean, significantly contaminating sediments and fisheries along the Japanese coastline, there is no plausible mechanism that could transport significant levels of contamination across the Pacific to reach beaches in the US or Australia.
Yes, there are detectable traces of those radioactive isotopes in US waters, but they are at very low levels, and their contribution to radiation doses is far below the natural background radiation level.
This does not necessarily mean they are completely safe (no radiation dose is low enough to be 100% safe), but the additional risks they present to living organisms, including humans, are negligible. Certainly, these levels are not causing radiation sickness, deformities or mass deaths of ocean life.
That is why we continue to focus on the big post-Fukushima problems in Japan itself.This is where you can occasionally still catch a fish whose contamination exceeds the official standards.
While the frequency of such catches has indeed fallen since 2011, they still occur and send a reminder of the ongoing risks and need for precautionary measures when it comes to seafood from Japan's northeastern coastline.
But to repeat: the idea that contamination from Fukushima presents a risk to the coastal waters and their ecosystems of the US or Australia is seriously over-stretched.
(Follow what Greenpeace does about the Fukushima nuclear crisis on this blog, where we also publisha twice weekly digest of news from the region. Also follow us on Twitter at@nukereaction.)