Manual of Naval Preventive Medicine
Chapter 1: Food Service Sanitation
Section IV: Inspection of Food Items

1-26. Inspection of Fish and Shellfish (Seafood).

Department of the Navy
Bureau of Medicine and Surgery

1. The USDC is responsible for all in-plant quality assurance inspections for Federal agency food acquisitions of seafood in the United States. All such products prepared in the United States and purchased for use in general messes and private messing facilities ashore and afloat must originate from plants under the supervision of the USDC and be marked with the USDC stamp to be acceptable. Processed seafood for clubs, messes, exchanges and commissaries must also originate from sources under USDC inspection; however, displaying the Federal inspection marks on the product label for commercial trade is voluntary rather than mandatory as with meat and poultry (mandatory inspection is expected to occur in the near future). Therefore confirmation of "approved sources" should be made by assigned veterinary personnel when the Federal inspection marks are not on the commercial product label.

2. Each container of unshucked shell stock (shellfish, oysters, clams, mussels) procured for Navy and Marine Corps use must be identified by an attached tag that states the name of the original shell stock shipper, the kind and quantity of shell stock, and an official certificate number issued according to the law of the jurisdiction where it originated. Fresh and frozen shucked shellfish must be packed in nonreturnable packages identified with the name and address of the original shell stock shipper, shucker, packer, or repacker, and the official certification number issued according to the law of the jurisdiction of its origin. Shell stock and shucker shellfish must be kept in the container in which they were received until they are used.

3. Fish must be checked carefully. Refrozen fish must not be used; that is, fish that have been frozen, thawed, and then frozen again. Fish that has been refrozen will have soft, flabby flesh, and a sour odor, and will be off-color; the wrapping paper may become moist, slimy, and discolored. The bottom of the box may be distorted.

4. Fresh fish have bright red gills, prominent clear eyes, and firm elastic flesh. Stale fish are dull in appearance, have cloudy and red bordered eyes and soft flesh; finger impressions are made easily and remain when digital pressure is released. Fish caught over the side at sea must not be consumed unless there is absolute certainty that they are not poisonous since cooking does not destroy the poisonous alkaloid in fish which can cause violent illness or death.

5. Fresh crustaceans (lobster and crab) must be alive to be accepted. Quality fresh whole lobster cannot be obtained after any period of storage. It should be purchased as a live product and it will remain satisfactory as long as it is alive and the flesh is not shrunken. When inspecting crab, lobster, or shrimp, the edible portion should be examined by organoleptic procedures to determine fitness for human consumption.