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Fukushima radiation present in Bering Sea, researchers say — but no cause for concern

Radioactive materials from the Fukushima incident eight years ago have arrived in the Bering Sea. State epidemiologists say the levels are extremely low and do not present a health concern.

Even though the contaminants are here, KNOM reports on why they are at levels below concern and how St. Lawrence Island residents have helped monitor them the whole way.

Several years after a Fukushima nuclear power plant was damaged in 2011, Gay Sheffield, with Alaska Sea Grant, says St. Lawrence Island residents started sending her five-gallon water samples, which she has shared with a larger research team.

“It doesn’t have to be frozen or anything. I mean, if you’re looking for radioactivity, I guess the good news is it’s going to be there whether it’s frozen or not. The sample was then sent to the Woods Hole Oceanographic Institution.”

The idea was to determine when Bering Sea coastal communities would see evidence of Fukushima contaminants, even in very small concentrations. Based on their knowledge of ocean currents, passed from generation to generation, St. Lawrence Island residents expected it to happen at some point.

Gambell resident Eddie Ungott wasn’t reachable by phone, but via a written statement he said he volunteered to collect samples, to help test Fukushima-related contamination in the water, with Sheffield every fall.

Multiple attempts to contact Ungott by phone were unsuccessful due to poor phone service in Gambell.

Ungott knew the Japanese currents 4,000 miles away would come to St. Lawrence Island, but he says he needed to know how it would affect the marine mammals his community hunts for subsistence. Sheffield wants to help Ungott answer that question for himself and the region.

According to Sheffield, small amounts of radioactive Cesium-137 have been found in these water samples since they started testing in 2015.

However, state epidemiologists say those levels and the 2018 results continue to be thousands of times too low to pose any health concerns. 2.4 becquerels per cubic meter was the level observed from the sample, while the Environmental Protection Agency (EPA) considers water levels of cesium-137 of up to 7,400 becquerels per cubic meter to be safe to drink.

Now, for the first time, Sheffield says, the latest results released in March showed the contaminants were at levels higher in the Bering Sea than they were before the 2011 nuclear disaster. So, scientists at Woods Hole said there was no mistaking: the elevated contamination was from Fukushima.

“It sounds like a small increase, I think the word was ‘uptick,’ to go from 2.0 to 2.4. But the ocean is very large, and their equipment is very precise.”

For several years, the nonprofit Woods Hole Oceanographic Institution has been testing the water samples provided by Sheffield and Ungott.

Dr. Ken Buesseler, a senior scientist with Woods Hole, studies radioactive elements in the world’s oceans and has been focused on Fukushima contaminants since 2011.

Cesium-137 is a radioactive isotope, which Buesseler says travels through ocean currents and behaves like potassium or salt. Since the initial release at Fukushima, the Cesium levels detected in the Pacific Ocean have decreased by about 15 percent, due to its half-life of 30 years. Meanwhile, Cesium-134, another radioactive isotope released from Fukushima, has a shorter half-life of two years, so Dr. Buesseler explains it is almost impossible to detect levels of that contaminant at this point in the Pacific Ocean.

He says partnering with Sheffield, Ungott, and other citizen scientists through a crowdfunding model has been beneficial for this project.

“We went from essentially a map of the west coast of North America, Alaska, and Hawaii, with no data, no results, to address the public concern, with now something like 500 data points, including in the Bering Sea. So, we’ve been able to then enlist people to help us, and as we do that, I think we’ve been able to educate people on what those levels really mean.”

Buesseler wants to reassure people that, despite the contamination, they can continue boating in the ocean, do their normal, water-based activities, and still eat the seafood without concern.

“What we have to watch out for is either being too dismissive of people’s concerns — and that’s often why the government will argue, ‘why bother measuring, because the levels are so low,’ which I don’t think is the correct response, because that doesn’t address their concern — or being too alarmist, people saying, ‘stay out of the ocean because there is Cesium there,’ and I think that’s also not the right response, because the levels are quite low.”

Buesseler along with other scientists reiterate that there is no reason to be concerned about the small amount of Fukushima contaminants contained in the Bering Sea, nor will be there cause for concern in the future as these radioactive levels will continue to diminish as time passes.

Seth Danielson, an oceanographer with the University of Alaska–Fairbanks, studies the motion of the ocean. He explains how the ocean currents and boundary flows brought Cesium-137, in extremely low levels, to the Bering Sea, almost eight years after the Fukushima nuclear event.

“This is the likely pathway that the contaminants from Fukushima made it up into the Northern Bering Sea. They followed the relatively swifter currents around the rim of the Gulf of Alaska, through the Aleutian Passes, into the Bering Sea, and then around the rim of the Bering Sea shelf. This is the boundary, the continental slope between the shallow shelf and the deep depth of the Central Bering Sea Basin.”

Danielson explains that, as more time passes, the contaminants will become more and more diluted in Alaskan waters. However, the currents will continue to move them through the Bering Sea.

“If you’re finding Fukushima waters near St. Lawrence Island, it’s extremely likely they are also going farther north into the Arctic.”

There are two pathways for dilution. Danielson says one is for swiftly flowing features distributed along the continental slopes, known as eddies, to mix the waters carrying Cesium-137 and other radioactive isotopes with the ambient Bering Sea waters. The other is the materials can diffuse, like when you put a little container of perfume in the corner of a room. The perfume will volatilize, and you’ll be able to smell it all the way across the room because it is diffusing out through the air. The same thing happens in the ocean water.

For about 20 years, Danielson has been studying the currents of the Bering Sea, and some of his research has included traditional knowledge, which he says is a benefit to his work. Sheffield would say the same is true in this case.

With their contributions to this worldwide project, she hopes Ungott and other Bering Strait regional residents will feel empowered.

“Based on the knowledge, the expert knowledge in our region, they knew to expect it. They took action. They found what they were looking for, and they have presented to the rest of the world… They’ve documented where the Fukushima plume is and that it has now entered Arctic waters.”

Sheffield says if the public wants to see more testing of Fukushima contaminants in the Bering Sea, then her and Eddie Ungott will try to gather more water samples later this year.

The years’ worth of data from the water samples and analysis of that information can be accessed for free at

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