Tuna Fish from Pacific Ocean is Radioactive Contaminated by Fukushima Nuclear Fallout

With many of the long term effects from the Japanese Fukushima Daiichi nuclear power plant disaster still ahead of us, a serious consideration should be made regarding the food chain and the possible radioactive contamination thereof. In this example, let's look at Tuna fish. Is it safer to buy canned tuna now, before possible contamination into its food chain?

They spawn in the Western Pacific between Okinawa and the Philippines and the Sea of Japan and they migrate over 6,000 nautical miles to the Eastern Pacific, eventually returning back to their birth waters to spawn again.
What do Tuna eat?

Tuna mostly eat small fish ranging from 1.5 inches up to 6 inches. Tuna will also eat squid, and very occasionally will consume crustaceans.
The small fish that tuna will eat include skipjack herring, flying fish, lancetfish, puffer fish, triggerfish and rabbitfish.