Manley, who studies kelp and seaweed, was also receiving phone calls from people worried about radiation in the ocean shortly after the accident. He contacted Kai Vetter, a researcher and professor at the University of California, Berkeley, who had already started a project monitoring the air for radiation after the accident.
They formed a group called Kelp Watch in the wake of the accident. The group involved 52 marine scientists taking kelp samples at sites ranging from Kodiak Island off the coast of Alaska, to Baja California, in Mexico, and as far east as Hawaii. To date, they have found no detectable levels of radioactive isotopes in kelp or seaweed tissue. Vetter told CNBC that they are certain there is some radiation from Fukushima in the kelp, but the levels are so low their equipment has not been able to detect it.
The radiation Buesseler was measuring in the Pacific was orders of magnitude smaller than what would be required to cause the aforementioned sea life die-offs in the Pacific.
Separate research from NOAA and other groups has tentatively connected some of these deaths to toxins released by plankton blooms — products likely of unusually warm ocean water common during El Nino. In any event, Buesseler said, if the levels were high enough to lead to die-offs around the Pacific, there would have to be greater marine life losses close to Japan, and there haven't been.
Radioactivity is everywhere, and most of it is naturally occurring.
"We are living in a radioactive world, and we are exposed to it all the time," Vetter told CNBC.
And to a certain extent, humans can handle it. However, radiation can be carcinogenic — sun exposure can cause skin cancer, for example. But small amounts of sun exposure are not necessarily harmful, and the body has repair mechanisms to handle damage. It is also important to keep radiation from specific sources in perspective.