In the aftermath of the 2011 tsunami off the coast of Japan, the Fukushima Dai-ichi nuclear power plant released cesium-134 and -137 and several other radioactive elements into the ocean at unprecedented levels. To this day, more than 50,000 people in Japan cannot return to their homes due to the radioactive contamination level on land. Although Fukushima is 5000 miles from the west coast of North America, ocean currents are still able to carry the containments towards the US some three years later. Shockingly however, no US federal agency is currently supporting the monitoring of ocean radioactivity in coastal waters that is causing high public concern. Dr. Ken Buesseler, of the Woods Hole Oceanographic Institution, is a marine scientist who increases scientific and public understanding of the sources, fates, and consequences of natural and human-made radioactive elements in the environment like the contaminants coming from Fukushima. Dr. Buesseler and his team are able to measure how contaminated the ocean is and measure the levels in the fish that inhabit them but also, they are trying to answer when fish will be safe to eat and how quickly contaminants either mix and move offshore with ocean currents or are buried near the coast. His efforts included leading an international  rapid response cruise off Japan shortly after the disaster and continued studies to track ongoing radioactivity leaks from the nuclear power plant site. Since January 2014, more than 250 seawater samples have been collected from San Diego to Alaska and Hawaii shores by citizen-scientists and crowd-funding has been used to analyze them (http://OurRadioactiveOcean.org).

Over the past 50 years, natural and anthropogenic radionuclides have been instrumental in addressing many important questions in oceanographic research. Yet knowledge gaps remain regarding their spatial and depth distributions and the temporal evolution of many radionuclides of importance to both oceanographic and human health issues. Dr. Buesseler's combination of expertise to apply radioactive isotopes to study marine processes and to address human health concerns is rare. His rigorous research therefore has an incredible impact on both the scientific community and the global community at-large. In fact, in 2011, he was noted as the ocean scientist with the highest number of top citations by the Times Higher Education for the decade of 2000-2010 thus supporting the innovative nature, accessibility and high impact of his research. Thus, Dr. Buesseler's research is necessary for understanding the health ramifications of radioactive elements within our oceans that can affect millions of people across the globe, as well as advancing our understanding of basic ocean processes, using radioactive elements as "tracers" to study the rates of ocean mixing and currents, how fast marine sediments sink and are buried, and uptake of carbon and nutrients in marine ecosystems.

Current research includes:

• Citizen-scientist Campaign: In January 2014, Dr. Buesseler launched a crowdfunding citizen-scientist campaign (OurRadioactiveOcean.org) to empower the public to support and sample for cesium isotopes in ocean waters. Using some of the most sensitive methods available, he and his team can "fingerprint" in any sample how much additional radioactivity has been added by Fukushima.

• Global Climate: Dr. Buesseler and his team are looking at the capacity of the ocean to store some of the carbon dioxide greenhouse gases we release as we burn fossil fuels to better understand the ocean's role in global climate. The faster carbon is taken up by marine algae and sinks into  the deep ocean, the more thorium-234 it carries with it, so by measuring this natural radionuclide, he and his team can say something about the larger carbon cycle.

• Research Cruises: Dr. Buesseler and his team participate in several week-long research cruises each year covering all the world's oceans, including the Atlantic, Pacific, Indian, Mediterranean, Black Sea, and oceans around Antarctica, and in the Arctic.