Radiation
The background level of radiation in oceans and seas varies around the globe. Measured in atomic disintegrations per second (Becquerels) of cesium-137 in a cubic meter of water.
Fukushima Radiation
On March 11, 2011, a magnitude 9.0 earthquake 80 miles off the northeast coast of Japan triggered a series of tsunamis that struck nearby shorelines and the Fukushima Daiichi nuclear power plant.