S. Wayne Mobley, Regional Environmental Health Specialist

Shellfish Sanitation Section

North Carolina Department of Environment and Natural Resources

Morehead City, North Carolina

National Shellfish Sanitation Program is a cooperative Federal Drug Administration (FDA), state, and shellfish industry program designed to certify shellfish products that are shipped interstate.

The FDA:

• provides an annual evaluation of state shellfish programs
• Reports to the national conference on the status of each state’s program
• Publishes a monthly list of interstate shellfish shippers certified for shipping shellfish

The shellfish industry:

• Works with seafood plants to assure that they meet certain standards
• Shellfish must be properly labeled
• Maintain records as to origin and disposition of shellfish shipped interstate

The state:

• adopts adequate laws to assure “clean and disease-free” shellfish
• classifies all shellfishing areas
• Patrols coastal areas (through the NC Division of Marine Fisheries)
• Inspects shellfish plants and issues certificates
• any other control measures as needed

Oysters and clams can pump up to 7 gallons of water per hour and, therefore, can concentrate chemical contaminants by X1000 and bacteria by X100

Major threats to the shellfish industry:

• Municipal sewage
• Coastal development
• Marinas
• Agricultural runoff

Shellfish Sanitation Program conducts annual sanitary surveys and must reevaluate the results of these surveys every 3 years.

Through this program areas are classified as

• approved
• Conditionally approved
• restricted

Surveyors take 30 samples in each area for two years and then classify an area. Then these areas are reviewed for their status after 3 years.

The samples are collected year around and the coliform bacterial content of the water is determined. If samples show more than 14 colony forming coliform bacteria in the samples, the area is closed.

Shellfish areas are automatically closed after heavy rains (roughly 1-1 1/2 inches). Contaminated freshwater runoff is a major problem for shellfish.

Recreational water samples are taken by the Shellfish Sanitation Program and this will become a federal mandate in 2002.

The coliform group of bacteria are aerobic or facultative anaerobic, gram-negative, non-spore forming, rod shaped, organisms that ferment lactose and produce gas within 48 hours at 35 degrees Celsius. Fecal coliform bacteria are a subgroup that form gas at 44.5 degrees Celsius.

Marinas are a detriment to water quality and threaten the quality of shellfish

Large “factory farms” are a problem. They also threaten water quality by introducing bacteria.

A red tide struck North Carolina in 1987. At first, scientists and agencies did not know what had happened. People had symptoms such as sneezing and runny nose.

The shellfish beds from Ocracoke Island (outer banks) to the South Carolina line were closed. Cell counts reached six million per liter.

Some shellfish houses went out of business. Some fishermen went out of business too.

The red tide killed large quantities of scallops in NC bays and sounds.

Shellfish diseases

Bacteria: Vibrio vulnificus (life threatening; 65% mortality

Vibrio cholerae

Vibrio parahaemolyticus

Salmonella spp.

Viruses Hepatitis A (rare)

Norwalk agent

Dinoflagellates Gonyaulax tanarensis (red tide)

Gonyaulax catenella (red tide)

Pytchodiscus brevis (red tide)

Harvesting and eating raw oysters in summer lead to high probability of sickness. Texas harvests all year; North Carolina has a season in the cooler months.

Several years ago, North Carolina oysters were decimated by the disease called Dermo

The Shellfish Sanitation Program in North Carolina inspects crabs, oysters, and clams

North Carolina is the number 1 produced of crab meat in the US.

Up to recently, NC was also number 1 in clams. Florida just passed us.

Economic fraud is increasing as cheap non-US crab meat is imported and mixed with US crabmeat and sold as 100% US blue crab.

Tamper-proof lids are now required in North Carolina