SoMAS professor Nicholas Fisher, Ph.D., and postdoctoral scholar Zofia Baumann and Daniel Madigan of Stanford measured the levels of two radioactive isotopes of cesium in bluefin tuna caught in

August 2011 off the coast of San Diego, California. Pacific bluefin tuna spawn in the western Pacific and many migrate in their first or second year to the waters of the eastern Pacific. Analyzing the radionuclide content in top marine predators such as bluefin tuna should provide unequivocal evidence of migratory routes and timing of these animals, the researchers concluded.

Such information would complement other migratory tracking tools and be useful for management and conservation of key fisheries and possibly other endangered species. The findings also demonstrate the interconnectedness of distant eco-regions, where events in one can be linked to findings in another region, even thousands of miles away.