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Shellfish Safety

Shellfish Consumer Protection

Steamed Hard Clams

Contaminated shellfish can make the consumer ill. The regulatory program administered by DEC's Shellfisheries Section is intended to make sure that clams, oysters, mussels and scallops harvested and offered for sale in wholesale commerce in New York State are safe for people to eat.

How do shellfish get contaminated?

Shellfish can become contaminated if they live in polluted water. Shellfish pump water around their bodies to obtain oxygen and filter out tiny plants and animals for food. This filtering may also pick up disease-causing microorganisms (bacteria, viruses and certain dinoflagellates) that can be eaten with the shellfish.

How does DEC protect shellfish consumers?

  • Classifying shellfish harvest areas: Each year DEC collects and examines thousands of water samples to make sure the shellfish growing areas are clean enough to allow the harvest of uncontaminated clams, oysters, mussels and scallops. If water quality is not up to New York State and national standards, DEC closes the area to shellfish harvesting.
  • Keeping commercial shellfishermen informed: Through a harvester licensing program, DEC keeps commercial harvesters informed about openings or closings of growing waters. In this way, harvesters can be sure that they are taking shellfish from clean waters.
  • Monitoring wholesalers: Under a wholesaler licensing program DEC inspects wholesalers to make sure that they handle, process and ship shellfish under strict sanitary conditions. Food inspectors check for cleanliness, assure that appropriate temperatures are maintained and that shellfish are properly packed for shipping. Shellfish samples are periodically analyzed for contaminants. In addition, DEC makes sure that shellfish are identified and tagged as to type, harvest area, quantity, wholesale shipper and date of shipment. Shellfish that are not tagged may be embargoed.

What other state agencies are involved?

The Department of Health (DOH) oversees food sanitation in restaurants.

The Department of Agriculture and Markets (A&M) is responsible for food sanitation in grocery stores and fish markets.

What happens if DEC finds violations?

Generally DEC Food Inspectors work with the wholesaler to rectify the violations. The inspectors explain to the wholesaler the importance of following proper procedures in the processing and storing of shellfish. In the case of repeated violations or severe violations the DEC may take steps that lead to the suspension or revocation of the wholesaler's permit following a hearing.

What does DEC do if shellfish cause an illness?

In the event of shellfish-borne illness, DOH asks DEC to identify the original shipper. Shellfish dealers' records are examined to trace the path of the shellfish back to the original shipper, the shellfish harvester, and the harvest area. If the shipper is located in New York State, DEC determines whether the shipper has violated state shellfish sanitation regulations. If the shellfish came from out-of-state, DEC notifies the U.S. Food and Drug Administration and the regulatory agency of the other state. DEC cooperates with DOH and A&M to find and destroy other shellfish from the contaminated shipment.

What are the results of the program?

The frequency and severity of shellfish-borne illness have decreased.

In the early 1920's an outbreak of typhoid fever, caused by contaminated shellfish from New York waters, sickened more than a thousand people in Washington D.C., Chicago and New York. The disease killed at least 150 people. Consumers lost confidence in shellfish and the shellfish industry was adversely affected nationwide.

Since that time, incidences of public illness from eating contaminated shellfish have been sporadic. Two recent instances in New York State, in 1961 and 1982, involved shellfish apparently tainted with an intestinal virus. Although people became sick, the illnesses were generally of short duration and no deaths were reported. There has been a very low incidence of shellfish-related illness recorded in New York State in recent years.

Closing polluted waters to shellfish harvesting has a long history in New York State. Today, approximately 200,000 acres, about 17% of the state's total growing waters, are closed to harvesting because sampling shows the waters are not clean enough. DEC conservation officers patrol closed areas to prevent illegal shellfish harvesting.

Can we ever make use of shellfish from closed areas?

Because shellfish can purge themselves of contaminants when immersed in unpolluted water, it is possible to take shellfish from a closed area and make them safe for people to eat.

The main ingredients in the cleansing process are clean sea water and time. The following are three processes that make it possible to use shellfish from closed areas:

  1. Conditional certification - In some closed growing areas water is polluted at predictable and short periods of time. A good example is an area closed because of contamination from land runoff following a rainstorm. After a rainstorm, the area is closed for seven days to allow shellfish to flush out possible contamination. On the eighth day the area is opened and remains open to shellfish harvesting until the next rainstorm occurs and the cycle begins anew.
  2. Transplanting - Shellfish are moved from a closed area to an open area where they must remain until self-cleansing is complete (a minimum of 21 days) and then they may be harvested. This requires a permit from DEC.
  3. Depuration - Shellfish from closed areas are placed in tanks of flowing disinfected sea water for a cleansing time of at least 48 hours. This process is conducted under strict DEC permit conditions governing the bacteria content, salinity, flow rate and temperature of the sea water. Depurated shellfish are tested to see if they are fit for public consumption before sale.

These three processes allow the use of a valuable marine resource under conditions that protect public health.

New York's Role in National Shellfish Sanitation

The Interstate Shellfish Sanitation Conference

various bivalve mollusks
The term shellfish refers
to bivalve mollusks such as
clams, oysters, and mussels.

New York State takes many steps to provide protection to consumers of shellfish. New York is a founding member of the Interstate Shellfish Conference (ISSC) (link leaves DEC's website). This organization is made up of shellfish producing and shellfish receiving states, the Food and Drug Administration (FDA), the Environmental Protection Agency (EPA), the National Marine Fisheries Service (NMFS) and the shellfish industry. A number of foreign nations that ship raw shellfish products into the United States also participate. ISSC members meet regularly to review shellfish sanitation issues and promote uniform shellfish safety standards for all members to conform to. These uniform shellfish safety standards are embodied in the National Shellfish Sanitation Program (NSSP), a set of detailed guidelines that specify how members handle shellfish safety issues and provide satisfactory protection for the consumers of bivalve shellfish. DEC implements New York State's shellfish sanitation program in accordance with the guidelines of the NSSP.

The National Shellfish Sanitation Program

The National Shellfish Sanitation Program (link leaves DEC's website) establishes uniform requirements for the handling of all raw bivalve molluscan products. All ISSC members must follow these guidelines for handling all raw shellfish products entering in interstate commerce on the wholesale level.

The NSSP guidelines describe in detail how participants must evaluate water quality (examine water samples for evidence of harmful bacteria, viruses, or algae) in shellfish harvesting areas. The guidelines also specify how the shellfish industry must handle shellfish and observe the appropriate sanitary requirements. These guidelines are vital to ensure proper sanitary conditions are maintained, from harvesting to shucking, packing, processing and shipping. The NSSP also specifies uniform requirements for participants' laboratories that examine water and shellfish samples and how frequently the states' law enforcement programs should patrol uncertified (closed) shellfish beds. All these guidelines are important to ensure that steps are taken to provide the consumer with a shellfish product that is free of potential pathogens.

The NSSP's minimum requirements are set forth in the "Guide for the Control of Molluscan Shellfish" which is written in a format that may be directly adopted as regulation by participants. The FDA oversees the NSSP by conducting annual evaluations of all participating states and foreign nations to assure that the minimum requirements of the NSSP are implemented uniformly by all member states and nations.

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