LIVE OYSTERS

8. LIVE OYSTERS
If handled carefully, live oysters can survive out of water for a week. Prior to shipment, fouling materials should be removed from the live oysters. Live oysters grown in suspended culture systems tend to have thinner shells than those grown on bottom, so extra care in packaging is advised. The area of harvest should always be considered when developing a shipping protocol. Sometimes, live oysters harvested from submerged beds sometimes must be “hardened” prior to shipping. Since these live oysters have not been exposed to the periodic dry conditions in the intertidal zone, they will sometimes gape when exposed to air. This holding process (hardening) sometimes takes as much as three weeks. Gaping reduces the shelf life, quality of the product, and customer satisfaction. If the live oysters are cleaned and placed in mesh bags in the intertidal zone where they are acclimated to periods of dryness for several weeks, repeated exposure to air will strengthen the adductor muscle that closes the shell. This can reduce the amount of gaping and can strengthen the product to undergo shipping. Live oysters from colder waters should be tested for Paralytic Shellfish Poisoning (PSP) as well as any additional tests that may be required by the importing country. Generally 50 pound boxes are preferred for shipping live oysters in order to avoid damaged shells. A padding material, possibly newspapers can be used in the bottom of the box. A plastic liner is added. Live oysters are then placed in the box in layers with the cup side down. This helps to retain the liquid. Live oysters are layered in this manner to about 2 inches from the top of the box. Additional padding is placed around the top and sides of the live oysters. The plastic liner is then folded over the top of the live oysters and a coolant (gel packs) is placed on top. As usual, gel packs should not come into direct contact with the product since the shells may rupture the gel pack or the product can become over-chilled. For added protection, the gel packs can be wrapped in newspaper. 39
The box should not be completely sealed since live oysters require air circulation. Markings on the packing box should indicate that it contains live product and should have up arrows.

In the United States, the size and format of the packing box labels are specified by the rules of the Interstate Shellfish Sanitation P r o g r a m . Most importing countries require that oysters and other m o l l u s c a n shellfish be managed under an equivalent program.