Tag Archives: Our Radioactive Ocean

Most Recent Measurements of Fukushima Derived Isotopes in the Northeast Pacific Ocean

By Jay T. Cullen

Satellite measurements of ocean temperature (illustrated by color) from July 28th to August 4th and the direction of currents (white arrows) help show where radionuclides from Fukushima are transported. Large scale currents transport water westward across the Pacific. Upwelling along the west coast of North America in the summertime brings cold deep water to the surface and transports water offshore. Circles indicate the locations where water samples were collected. White circles indicate that no cesium-134 was detected. Blue circles indicate locations were low levels of cesium-134 were detected. No cesium-134 has yet been detected along the coast, but low levels have been detected offshore. (Woods Hole Oceanographic Institution)
Satellite measurements of ocean temperature (illustrated by color) from July 28th to August 4th and the direction of currents (white arrows) help show where radionuclides from Fukushima are transported. Large scale currents transport water westward across the Pacific. Upwelling along the west coast of North America in the summertime brings cold deep water to the surface and transports water offshore. Circles indicate the locations where water samples were collected. White circles indicate that no cesium-134 was detected. Blue circles indicate locations were low levels of cesium-134 were detected. No cesium-134 has yet been detected along the coast, but low levels have been detected offshore. (Woods Hole Oceanographic Institution)

The purpose of this post is to report on new results coming out the crowd-funded Our Radioactive Ocean program headed up by Dr. Ken Buesseler of Woods Hole Oceanographic Institution. This post is part of an ongoing series dedicated to scientific inquiry into the impact of the triple meltdowns at Fukushima on the health of the North Pacific Ocean and residents of the west coast of North America. Measurements of the cesium radioisotopes 134-Cs (half life ~ 2 years) and 137-Cs (half life ~30 years) were made on samples collected on a transect between Monterey Bay CA and Dutch Harbor AK this summer. Because of its relatively short half life 14-Cs serves as an unequivocal tracer of Fukushima contamination in the environment. Fukushima derived 134-Cs was detected at offshore stations with a maximum activity of ~ 2 Bq/m^3 and total 137-Cs activities of ~7 Bq/m^3 of seawater. Measurements have yet to detect 134-Cs in nearshore waters sampled up and down the North American west coast. These activities of Cs are orders of magnitude below levels thought to pose a measurable risk to human health or marine life, according to international health agencies.


For a primer on radioactivity in the ocean and the units used to discuss radioactive elements in the environment please visit this post.

A press release from WHOI regarding these new results can be found here and details about sampling locations and activities of Cs detected are available here.

At a great majority of sites sampled along the coast and offshore the activity of 134-Cs is below detection limit (~legacy contamination resulting from atmospheric weapons testing in the 20th century. Similar to previous work by Dr. John Smith of the Department of Fisheries and Oceans Canada the presence of the contaminated plume of seawater owing to releases from Fukushima can be detected in offshore stations (150 – 1500 km) with levels of 134-Cs approaching 2 Bq/m^3 and total 137-Cs (bomb + Fukushima) of about ~7 Bq/m^3. These levels of 137-Cs are similar to levels in the North Pacific Ocean that were present in 1990 owing to the combined effects of Chernobyl and weapons testing fallout as shown in the figure below.

Activity of 137-Cs in the North Pacific after Povinec and others (2013) http://www.biogeosciences.net/10/5481/2013/bg-10-5481-2013.html with arrows indicating the impact of Chernobyl, 2008 137-Cs activity in the Irish Sea and 2014 levels offshore of western North America post Fukushima for comparison.
Activities of these isotopes were about 10 million fold higher in coastal waters near the Fukushima Dai-ichi nuclear power plant off Japan in the weeks following the beginning of the disaster in March and April 2011 when rates of release and seawater concentrations were at their peak. Current releases from the plant support seawater activities on the order of 10’s-100’s of Bq/m^3 within 2 km of the plant site. The highest activities associated with the most contaminated seawater from Fukushima are predicted to travel across the North Pacific with prevailing currents and arrive in North American waters between this year and next. These offshore activities of Fukushima derived 137-Cs of ~ 5 Bq/m^3 exceed predicted activities of ~3 Bq/m^3 suggesting that offshore activities are likely reaching near peak values. The measurements being made by the international scientific community will undoubtedly help to improve our understanding of mixing and transport in the oceans.

The activities of radiocesium being detected offshore are well below levels thought to represent significant radiological health risks to marine organisms or residents of the west coast of North America. To this point no 134-Cs from the contaminated plume approaching the coast has been detected in nearshore waters. Ongoing monitoring by programs like Our Radioactive Ocean and its partner program InFORM which are making measurements of contamination in seawater and marine organisms will be key to understanding impacts of the Fukushima on our environment.

MEOPAR Announces Funding for New Ocean Fukushima Radioactivity Monitoring Project

University of Victoria Press Release

Integrated Fukushima Ocean Radionuclide Monitoring (InFORM) Network: A collaborative radiation monitoring network to determine and communicate environmental risks for Canada’s Pacific and Arctic Oceans from the Fukushima-Daiichi nuclear accident

A new marine radioactivity monitoring network that will engage scientists in Canada and the US, health experts, non-governmental organizations—and citizen scientists along the British Columbia coast.

The InFORM Network—which stands for Integrated Fukushima Ocean Radionuclide Monitoring—is being funded by $630,000 over three years by the Marine Environmental Observation Prediction and Response Network (MEOPAR).

Since the 2011 tsunami and Fukushima-Daiichi nuclear disaster in Japan, there’s been widespread concern along the coast of western North America about the potential danger posed by low-level radioactivity crossing the Pacific Ocean.

“There’s great public demand for information about the impact of the Fukushima disaster on the marine ecosystem and on the health of British Columbians,” says Cullen. “Our goal is to provide the public with the best information possible about risks to the environment and their health.”

Research partners in the network include: Woods Hole Oceanographic Institution in Massachusetts; Health Canada; the University of Ottawa; the University of British Columbia; and Fisheries and Oceans Canada (DFO).

Ocean circulation models disagree on the timing and concentrations of radioactive elements expected off BC. The radioactive plume of seawater arrived along our coast in June 2013, and levels detected so far don’t pose a health risk.

“In the next few years, as the highest concentrations from this plume arrive, we need to know what the concentrations are and what kind of risks they pose,” says Cullen. “And we won’t know that unless we monitor the situation properly.”

The network will involve NGOs such as the Clayoquot Biosphere Trust, the Georgia Strait Alliance, the Raincoast Education Society, the Living Oceans Society and the David Suzuki Foundation, which will help with public outreach, information transfer, and recruitment and training of citizen scientists.

The plan is to set up 10 to 15 community sites along the BC coast where volunteer citizen scientists will collect water and seafood samples monthly or bimonthly for analysis.

Those samples will supplement measurements already being taken offshore by DFO and an existing citizen scientist network coordinated by Woods Hole that extends from the Bering Strait to San Diego.

“End-user involvement is a key pillar of this network,” says Cullen. “By engaging directly with the public, we’re inviting those with a stake and interest in marine environmental risk assessment to get involved.”

Cullen says results will be disseminated online and through community town hall meetings up and down the coast. He’s currently setting up an InFORM website, and results will also be posted on the www.ourradioactiveocean.org/ website hosted by Woods Hole.

MEOPAR is a team of Canadian researchers in the natural and social sciences who are trying to better understand and predict the impact of marine hazards on human activities and ecosystems. It’s hosted by Dalhousie University in Nova Scotia and funded by the federal Networks of Centre of Excellence Program.

For more information on the InFORM network, visit www.FukushimaInform.ca and Facebook, follow @FukushimainFORM or contact Jay Cullen at jcullen@uvic.ca.