Radioisotopes Tracking Tuna Migration

Understanding the movement of Fukushima-derived radioactivity through marine ecosystems may come down to getting a better handle on the tiniest of creatures—the microscopic plankton that take up so much volume in the sea. But one species that has become emblematic of the disaster is a shimmering giant: the Pacific bluefin tuna. Bluefin tuna born before the Fukushima disaster did not have elevated levels of cesium-134, but those caught in August 2011 did. (Illustration by Eric S. Taylor, © Woods Hole Oceanographic Institution)