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Risks of Eating Shellfish-Seafood and Aquatic Life

Molluscan shellfish are defined as oysters, clams, and mussels. They pose risks that are different from fish and crabs. We have developed a program to protect consumers, because molluscan shellfish are filter feeders and often eaten raw. Molluscan shellfish harvest areas are classified on shellfish harvest maps. These maps show areas that are:

  • Approved,
  • Conditionally approved,
  • Restricted, or
  • Prohibited for harvest.

Approved and conditionally approved harvest areas open or close based on:

  • Rainfall,
  • River flow,
  • Bacteriological results,
  • Presence of biotoxins (e.g. red tide), or
  • Illness investigations linked to a harvest area.

We open or close approved and conditionally approved  . We do this through a marine order.

Restricted and prohibited areas are classified based on levels of fecal pollution, human pathogens, or contaminants. We issue a marine order to classify restricted or prohibited areas. You should have a current shellfish classification map before harvesting molluscan shellfish. This will help you find the approved and conditionally approved harvest areas.

You may go to our classification map page to view the most current maps. You can also call us at 512- 834-6757. You can find the status of shellfish harvest areas from the shellfish status page.

You can also call the Seafood and Aquatic Life Group at 512-834-6757 or by calling a24-hour, in-state only, toll-free phone number 800-685-0361.

Buying Shellfish

Buy and use ONLY raw oysters, clams, mussels, or whole or roe-on scallops as shellstock (in-the-shell) or shucked shellfish (removed from the shell) that come from certified interstate shellfish shippers.

Do not buy molluscan shellfish from any source not listed in the FDA’s Interstate Certified Shellfish Shippers list. This includes avoiding recreational or commercially-licensed shellstock harvesters or any other source not listed. Do not buy shellfish that:

  • Aren’t properly labeled or tagged,
  • On arrival do not have an internal meat temperature of:
    • 50º F (10º C) or less for shellstock, or
    • 45º F (7º C) or less if shucked.

You should check shellstock tags and shellfish labels when you get them. Follow these steps:


Look for the Following Information on Tags or Labels 

Shellstock Container Tags

  • Name, address and certification number of the certified shipper
  • Original shipper's certification number (if different from above)
  • Date of harvesting
  • The most precise identification of the harvest location as is practicable including the two-letter state abbreviation. When the molluscan shellstock has been in wet storage in a dealer's operation, the tag shall state: "THIS PRODUCT IS A PRODUCT OF (Name of State) AND WAS WET STORED AT (Facility Certification Number) FROM (Date) TO (Date)".  
  • Quantity and type of shellfish (e.g., 1 sack oysters), and the following statement in bold capitalized type on each tag
    • "THIS TAG IS REQUIRED TO BE ATTACHED UNTIL CONTAINER IS EMPTY AND THEREAFTER KEPT ON FILE FOR 90 DAYS"; and, the consumer information statement adopted by the ISSC or its equivalent as approved by the Shellfish Control Authority.

Shucked Shellfish Labels

  • Name, address, and certification number of the packer or repacker
  • On containers of unfrozen product less than one-half gallon, the words "Sell By" or "Best If Used By" followed by the name of the month and the day of the month
  • On containers of one-half gallon and larger, the words "Date Shucked" followed by the date the product was shucked and the date on the lid
  • On frozen product, the words "Best If Used By" followed by the date and frozen shellfish must also be labeled with the words "Frozen", "Individually Quick Frozen", or "IQF" impressed, embossed, lithographed, or otherwise permanently recorded on the container. Stamping is not allowed, except for the date itself
  • STORE shellstock and shellfish properly
    • Separate from all other raw and cooked food
    • Reduce meat temperature as required for shellfish to 45° F within 2 hours of receipt
    • Ensure good air circulation around shellstock
    • Keep off the floor and up on pallets or shelves
    • Maintain lot source identification by tags, labels or record keeping
    • Do not commingle (mix) different lots or species
    • File and retain the tag for 90 days after the container is emptied
    • Keep records that indicate which shellfish are sold or served on which days
  • SELL AND SERVE only live shellstock
    • For oysters, test by tapping open shells with a hard object and discard shellstock which does not close its shell
    • Use a molluscan shell only once as a serving container and only for the oyster that comes in that shell