Sky-High Radiation Found in Fukushima Fish

[FBaggins]

62. Sure it would.

In this case you replace the dilution of a concentration of contamination across of growing volume of water... with a fish that leaves the area of contamination for an area without it. The effect is the same.

The fish involved in this story is obviously one that stays near (and feeds in) an area on the sea bottom where large amounts of contamination settled. If it were a migratory fish, it wouldn't stay in the area of contamination.

and high levels were discovered in tuna in CA.

Only if you redefine "high" to mean something entirely different from how everyone else reads it. Total radioactivity was indistinguishable from other tuna, but the amount attributable to Cesium was something like 5bq/kg (when 1bq/kg is more common). This is a truly insignificant figure by any estimation... so calling it "high" is a bit disingenuous.