How did a nuclear reactor fuel element wind up in shrimp?
Fukushima?
Not likely.
If any amount of Cs-137 was in the discharges from Fukushima the Chinese would have had a news blast about it the next day.
China is watching Japanese discharges like a hawk.
Fukushima?
—
Possibly. The shrimp was from Indonesia. The radioactive material from Fukushima would tend to sink to the bottom, where the shrimp feed. The Cesium-137 was detected at 68 Bq/kg, far below the 1,200 Bq/kg threshold for concern.
1 becquerel (Bq) = 1 count per second (cps).
68 Bq (cps) x 60 cpm/cps = 4080 cpm.
Background is ~60 cpm, mildly radioactive (varies depending on the isotope).
From what I remember about rule-of-thumb,
100,000 cpm = 0.1 mrem/hr (Gamma).
1200 Bq = 72,000 cpm, <0.1 mrem/hr, not dangerous unless consumed.
Note: 2.2 pounds of steamed shrimp is good eating.