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April 18, 2014

United States

Florida—David Flushing Responds to Question
about Radiating Shrimp


In the first week of April 2014, the Food and Drug Administration (FDA) approved the radiation of crustaceans—shrimp, prawns, crabs and lobsters—to control pathogens and extend shelf life.  The new rule covers raw, frozen, cooked, partially cooked, shelled, dried and ready-to-cook crustaceans.


On April 15, 2014, in his report on FDA’s approval, John Sackton, editor and publisher of, an online, subscription-based, fisheries news service, mentioned that Crystal Seas Oysters, which fishes, processes and markets oysters, radiates live, in-shell oysters.  Crystal Seas’ webpage says the radiation treatment eliminates Vibrios to undetectable levels in live oysters, while keeping the oysters “cold from reef to table”.


Shrimp News: On April 17, 2014, I posted the following question to this webpage: Does anyone know if live shrimp broodstock and postlarvae could be radiated to eliminate Vibrios and possibly EMS?  Presumably, the shrimp produced from the process would not need to carry the radiation symbol, especially if only the broodstock were radiated.


David Flushing (, one of the pioneers of shrimp farming in the Western Hemisphere, responded: “Irradiation destroys living cells.  If Crystal Seas is not killing their oysters, then they may be shortening their market ‘shelf life’ by damaging cells needed to remain alive.”


“But Shrimp News’ question whether live shrimp broodstock and postlarvae could be radiated to eliminate Vibrios and possibly EMS, is interesting.  It appears more likely that irradiation treatment sufficient to kill bacteria and virus would also kill critical live cells and possibly damage DNA.  If so, then raising treated postlarvae to an adult market-size shrimp might be problematic.”


“Nevertheless, tweaking irradiation dosage and methodology makes the possibility interesting.”


“The Centers for Disease Control and Prevention (CDC), on its page Irradiation of Food, states:”


The high-energy ray is absorbed as it passes through food, and gives up its energy.  The food is slightly warmed.  Some treated foods may taste slightly different, just as pasteurized milk tastes slightly different from unpasteurized milk.  If the food still has living cells, (such as seeds, or shellfish, or potatoes) they will be damaged or killed just as microbes are.  This can be a useful effect.  For example, it can be used to prolong the shelf life of potatoes by keeping them from sprouting.  The energy can induce a few other changes.  At levels approved for use on foods, levels of the vitamin thiamine are slightly reduced.  This reduction is not enough to result in vitamin deficiency.


Shrimp News: This morning, I called Crystal Seas and asked a company representative if the oysters were still alive after the radiation process, and the answer was “Yes”.


Sources: 1. Email to Shrimp News International from David Flushing.  Subject: Shrimp News Q on Radiation.  April 17, 2014.  2. Bob Rosenberry, Shrimp News International, April 18, 2014.

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