Radio active tuna sand

Yum yum bumblebee tuna... No more tuna sand if you cannot find the cans made before March.

The bulk of the debris will likely not be radioactive, as it was presumably washed out to sea during the initial tsunami - before much radioactivity had leaked. But this shows the power of the currents from Japan to the West Coast.

Of course, fish don't necessarily stay still, either. For example, the Telegraph notes that scientists tagged a bluefin tuna and found that it crossed between Japan and the West Coast three times in 600 days:

That might be extreme, but the point is that fish exposed to radiation somewhere out in the ocean might end up in U.S. waters.
(http://www.washingtonsblog.com/2011/06/radioactive-fish.html)