|Almost all daily activities
involve some risk. Individuals attempt to manage risks by gathering
information that will help them make informed choices that are
appropriate for their own values, needs, preferences, and life-style.
Although Americans enjoy one of the safest food supplies in the
world, health risks may still be associated with some foods. For
seafood, potential health risks are related either to specific
fish or shellfish or to the way they are handled, stored, or prepared.
Several studies have
helped put seafood safety issues into perspective. A 1991 study
by the National Academy of Sciences concluded that "most
seafood available to the U.S. public are wholesome and unlikely
to cause illness." The study did, however, identify areas
of risk and priority needs for research and education, and it
recommended improvements in the seafood surveillance system.
The FDA also recently
reviewed seafood safety issues and concluded that "the
vast majority of seafood in the marketplace is safe to eat,
and overall, American shoppers can be confident that the fish
they buy will provide a healthful meal." A recent FDA study
estimated that the risk of illness from seafood was 1 illness
from seafood in 250,000 servings. The same study estimated a
risk of about 1 illness in every 25,000 servings for chicken.
agree that the seafood supply generally meets acceptable safety
standards, potential health risks can be associated with bacterial
or viral contamination, naturally occurring toxins, and chemical
The following information is provided to help you understand
specific seafood safety issues and avoid potential risks.
Most food safety
experts believe that improper food handling is the most important
safety concern and the leading cause of food-borne illness in
the United States. Seafood is one of the most perishable foods,
and proper handling, and preparation are essential to maintain
quality and ensure safety. All raw foods contain bacteria, which
can grow and multiply rapidly if food is left for several hours
at room temperature. Observe the following handling tips to
maintain seafood quality and avoid illness:
Keep seafood cold
at all times. Always keep seafood at a temperature as close
to 32*F as possible. Get seafood home as quickly as possible.
Store fresh seafood in the coldest part of the refrigerator
(meat or vegetable compartment or on open shelves close to the
back) and frozen seafood in the freezer, and keep it there until
Don't transfer bacteria from one food or food contact surface
(your hands, utensils, knives, cutting boards) to another when
handling, storing, or preparing seafood. Thoroughly wash your
hands, utensils, containers, and any food preparation surfaces
after touching or preparing raw seafood, meat, or poultry.
Store raw seafood
in leakproof containers or bags when possible. Prevent seafood
from dripping or splashing onto other foods and prevent seafood
from being contaminated by other foods.
Handle and store
raw and cooked seafood separately. It's especially important
to prevent raw foods from touching, dripping, or splashing onto
foods that won't be cooked again before being eaten.
Cook seafood properly
to ensure safety. Most experts suggest cooking seafood to an
internal temperature of at least 145*F. A temperature of 160*F
or higher is recommended to kill bacteria, but excessive exposure
to high temperatures can easily cause seafood to be overcooked
and become dry and tough. Properly cooked fish should be opaque,
moist, and flake easily.
Cool cooked seafood
as rapidly as possible. When preparing large amounts of cooked
seafood (such as a large pot of clam chowder), put the cooked
product into small, shallow containers, which will cool faster
in the refrigerator.
Thaw seafood properly.
Frozen seafood should be thawed in the refrigerator or under
cold continuously running and draining water. Never thaw seafood
in warm or standing water or at room temperature - environments
that allow bacteria to grow.
Eating Raw Seafood
is traditionally eaten raw, even though eating raw foods is
considerably riskier than eating cooked foods. Cooking seafood
properly is necessary to destroy disease-causing organisms that
occur naturally or that can be introduced during handling, storage,
or preparation. When seafood or any other food is eaten raw
or partially cooked, the risk of illness is significantly increased.
Some raw products that have been implicated in human infection
are: ceviche (fish and spices marinated in lime juice); lomi
lomi (salmon marinated in lemon juice, onions and tomato); poisson
cru (fish marinated in citrus juice, onions, tomatoes and coconut
milk); salmon roe; sashimi (chunks of raw fish); sushi (pieces
of raw fish with rice and other ingredients); green herring
(lightly brined herring); drunken crabs (crabs marinated in
wine and peppers); cold-smoked fish; and, undercooked grilled
shellfish, like clams and oysters, are commonly eaten raw or
partially cooked. Because of where they live, how they feed,
and how they're eaten, they could contain bacteria or viruses
that can cause illness.
Bivalves live in
coastal areas close to the shore. Bacteria and viruses from
human and land animal sources can be carried into coastal waters
with runoff from the land, in sewage discharges, or from other
sources. These shellfish, which obtain food by pumping water
through their digestive system and filtering out small organisms,
may collect bacteria and viruses from the water in which they
live. People can ingest these organisms when they eat these
products raw. For these reasons, potential health risks associated
with eating raw bivalve shellfish are usually directly related
to the quality of the waters from which they were harvested.
The FDA and coastal
state governments oversee the National Shellfish Sanitation
Program, which sets standards for waters in which shellfish
are grown and requires those waters be tested regularly. The
program is designed to ensure that shellfish are harvested from
certified waters and meet safety standards. Because of this
program, large amounts of raw clams and oysters are eaten each
year without incident.
illnesses, however, still occur. Many of the reported illnesses
are believed to be the result of "bootlegging" or
the illegal harvesting of shellfish from uncertified waters.
Coastal states have greatly increased penalties for bootleggers,
and the FDA has made the elimination of bootlegging a priority.
Other illnesses result from bacteria which are natural summertime
inhabitants of clean (unpolluted) coastal waters. When present
in shellfish waters, these bacteria, which include Vibrio cholera,
Vibrio parahaemolyticus, and Vibrio vulnificus, can accumulate
in molluscan bivalves. Although the bacteria do not affect the
health of the shellfish, they can cause illness in humans consuming
raw or undercooked bivalves. Individuals whose physical health
is weakened by certain preexisting medical conditions are considered
"at risk" for contracting Vibrio vulnificus infections.
Vulnificus infections are serious, causing death in 46% of people
who contract them. Therefore, some states like Louisiana and
California require warnings on raw bivalve packages and on menus
of restaurants serving raw bivalve shellfish. Raw or partially
cooked bivalves should not be eaten by anyone with one or more
of the "at risk" conditions. At risk conditions include
compromised immune systems, AIDS, cancer (especially during
chemotherapy), liver disease, diabetes, hemochromatosis, chronic
kidney disease, inflammatory bowel disease, steroid dependency,
achlorhydria, and other stomach problems. Additional high-risk
individuals include alcoholics, infants, pregnant women, the
elderly, and people on antacid therapy.
The following tips
can help healthy individuals who choose to eat raw bivalve molluscan
shellfish reduce potential risks:
clams, oysters, and mussels from a licensed, reputable dealer.
If you harvest clams, oysters, or mussels yourself, obey all
posted warnings and verifY with local authorities that the waters
are certified for shellfish harvesting.
Don't use dead shellfish, whose shells don't close tightly when
tapped or agitated. (Soft-shell clams can't completely close
their shell, but should move when touched.)
Handle and store shellfish properly. Keep shellfish cool and
damp. Rinse when necessary to remove dirt or debris, but avoid
prolonged contact with freshwater, drastic temperature changes,
and airtight containers. Don't allow other foods to drip on
shellfish during storage, and prevent contamination by using
clean containers and utensils for storage, preparation, and
serving. Food handlers should wash their hands with warm, soapy
water before and after preparing and serving shellfish.
Consider cooking shellfish properly to reduce potential risks
further. The FDA recommends that live oysters, clams, and mussels
be steamed for 4 to 9 minutes or that they be placed in boiling
water and cooked for 3 to 5 minutes after the shells have opened.
Shellfish should be cooked in small batches to ensure thorough
cooking. Shucked shellfish should be boiled or simmered for
at least 3 minutes or until edges curl, fried in 375oF oil for
at least 3 minutes, broiled 3" from heat for 3 minutes,
or baked for 10 minutes at 450oF.
Raw fish dishes such
a sushi and sashimi and uncooked marinated dishes like ceviche
have become popular in the United States. Disease causing bacteria
and viruses don't normally occur in the muscle of a whole fish,
or the part that is usually eaten. However, fish fillets and
steaks can be contaminated by improper handling. Because raw
fish dishes aren't heated to a temperature that would normally
kill bacteria, only high quality or sushi grade products should
be used. If you choose to eat raw or uncooked fish, purchase
the fish from reputable establishments that have high standards
for quality and sanitation.
tapeworms, flatworms, and roundworms), which occur naturally
in some fish, are another potential safety concern when raw
fish are eaten. The National Academy of Sciences found that
human parasitic infections from seafood are rare in the United
States, and as yet there is no evidence of a significant increase
due to the growing popularity of raw fish dishes. While sushi
chefs are trained to detect and remove parasites, home chefs
can eliminate potential health risks from parasites only by
proper cooking or freezing.
Cooking fish to an
internal temperature of at least 145oF for at least 1 minute
will kill parasites. Dead parasites are not harmful when ingested
but may be aesthetically unappealing. Even though preparing
raw fish dishes at home is not encouraged, if you choose to
do so use frozen fish. The FDA recommends that fish intended
for raw consumption be frozen to an internal temperature of
-4oF for 7 days or at -3oF internal temperature for 15 hours
to kill parasites. The Food Code recommends these freezing conditions
to retailers who provide fish intended for raw consumption.
The seafood industry
inspects fish and removes parasites using a procedure called
candling. Even the most diligent operations, however, may not
find all parasites. Always conduct a quick visual check of your
food before you cook it to avoid unpleasant surprises. Most
retailers will replace products if parasites are found.
be produced by naturally occurring marine algae and can accumulate
in fish and shellfish that inhabit the same marine environment.
Unlike bacteria and parasites, toxins are not destroyed by cooking.
There are five recognized fish poisoning syndromes in the United
States caused by marine species consuming toxic algae: ciguatera
fish poisoning (CFP), paralytic shellfish poisoning (PSP), neurotoxic
shellfish poisoning (NSP), diarrhetic shellfish poisoning (DSP),
and amnesic shellfish poisoning (ASP). To reduce potential health
risks, purchase seafood from reputable sources, handle it properly,
and exercise caution when eating fish and shellfish that you've
caught in unfamiliar waters.
Ciguatoxin is a marine
toxin that can accumulate in some tropical saltwater reef fish,
and poisoning can occur when those fish are eaten. Commercial
fishers are generally able to avoid areas that contain ciguatoxic
fish. Recreational anglers who aren't familiar with local fishing
areas are more likely to catch toxic fish unknowingly. More
than 90 percent of the reported cases of ciguatoxin poisoning
in the United States from 1978 to 1987 occurred in Puerto Rico,
Guam, the Virgin Islands, and Hawaii. Visitors to tropical areas
should patronize only reputable dealers and restaurants and
should be prudent about the recreationally caught reef fish
The four types of
shellfish toxins are produced by marine algae during periods
of excessive growth, or "blooms." A common algae bloom
is the "red tide." Waters in which shellfish are harvested
are monitored and tested, and waters are closed to shellfish
harvesting when toxins that can cause illness are likely to
be present. To minimize the risk of illness further, individuals
who harvest their own shellfish should check with local authorities
and heed all warnings regarding shellfish harvesting restrictions.
Escolar, puffer fish,
and whelk may contain naturally occurring toxins that do not
involve marine algae. Escolar (Lepidocybium flavobrunneum and
Ruvettus pretiosus) contains a strong purgative oil, called
gempylotoxin. FDA advises against importation.
Puffer fish, or fugu,
which may contain tetrodotoxin, may not be imported except under
strict certification requirements and specific authorization
from FDA. Poisonings from tetrodotoxin have usually been associated
with the consumption of puffer fish from waters of the Indo
Pacific ocean regions. However, several reported cases of poisonings,
including fatalities, involved puffer fish from the Atlantic
Ocean, Gulf of Mexico, and Gulf of California. There have been
no confirmed cases of poisonings from Spheroides maculatus but
there is still reason for concern.
Tetramine is a toxin
that is found in the salivary glands of Neptunia spp., a type
of whelk. The hazard can be controlled by removing the glands.
Histamine or scombrotoxin
is caused by improper fish handling rather than by naturally
occurring marine algae. Histamine or scombrotoxin is produced
when fish such as tuna, mackerel, bluefish, mahi-mahi, and amberjack
begin to spoil. When these fish are exposed to temperatures
that allow rapid bacterial growth, histamine is formed, which
can cause an allergic-like reaction when the fish is eaten.
This illness, called histamine or scombroid poisoning, isn't
severe for most people, but it can be uncomfortable. Because
histamine is not destroyed by cooking, this illness must be
prevented by handling and cooling fish properly. Histamine can
be rapidly produced when fish are allowed to remain on the deck
of a fishing boat or a dock for long periods in warm weather.
Recreational anglers should plan ahead and have plenty of ice
available to keep their catch cold. When purchasing fish, avoid
products that are not adequately chilled. Store fish at temperatures
as close to 32oF as possible, and avoid exposing it to warmer
temperatures for a long time.
risks from chemical contaminants in fish have been more difficult
to quantify. The long-term health effects of PCBs, mercury,
and pesticides have not been clearly demonstrated in humans,
but there is evidence that exposure to these chemicals over
time may affect reproduction, growth and development in children,
and lifetime cancer risk. Recreational and subsistence anglers,
pregnant women, and children who eat large amounts of sport
fish caught from contaminated waters are at greatest risk.
The FDA sets action
and tolerance levels for chemicals that are suspected to pose
a potential health threat. These levels are intended to protect
consumers from food-borne chemical hazards. Federal and state
government agencies monitor contaminant levels in fish and shellfish.
When levels exceed tolerance or action levels, contaminated
bodies of water are closed to commercial fishing or an individual
species of fish is banned from the commercial marketplace.
in most commercial species that have been tested are well below
established limits. Ocean species that spend their entire life
far from the shore are less likely to have contaminants than
those that stay in near-shore areas. Large predatory fish that
live for a long time, like swordfish, shark, albacore tuna, tilefish, and king mackerel can accumulate higher
levels of contaminants such as mercury. These species are tested
more frequently to ensure that the commercial supply meets government
Twenty percent of
the fish and shellfish eaten in the United States are harvested
by individuals for their personal consumption. Recreational
and subsistence anglers may catch fish from waters that are
known to contain elevated levels of chemical contaminants, even
though commercial fishing in those waters is banned. Those individuals
who consistently consume fish from contaminated waters are at
levels in recreational fish exceed the tolerance or action limits,
health authorities issue fish consumption advisories, which
advise anglers, and higher-risk individuals to limit their consumption
of certain types and sizes of fish or from specific bodies of
water. In Georgia, advisories are produced by the state Department
of Natural Resources (DNR) and published in their Guidelines
for Eating Fish from Georgia Waters (see "Catching Your
Own Seafood" chapter).
The following guidelines
can help individuals concerned about chemical contaminants in
fish and shellfish manage potential health risks:
Eat a variety
of different fish and shellfish.
Avoid eating excessive amounts of any single type of fish or
Avoid eating the internal organs of fish, the tomalley of lobsters,
and the mustard of crabs. They can contain significantly higher
amounts of contaminants than the flesh.
When catching your
own fish, check and follow all applicable health advisories.
Advisories are available from local and state health departments,
and state fisheries agencies like the Georgia Department of
Natural Resources (DNR).
High-risk individuals, including pregnant women, nursing mothers,
women of child-bearing age, and children under age 15, should
limit their consumption of species known to have elevated levels
If you choose to eat sport fish that may contain elevated levels
of contaminants, remove skin and trim away fatty areas. Use
cooking methods like grilling or broiling, which allow fats
and juices to drain away.
True food allergies are not very common, occurring in only about
2% of the general population. Seafood allergies have been estimated
at less than one tenth of one percent. True food allergies are
abnormal responses of the body's immune system to certain foods
or food ingredients. Specifically, a protein in the offending
food "fools" the immune system into recognizing it
as a foreign invader. The immune system produces antibodies
to help fight the "invasion." Antibodies bind with
other cells and this complex releases histamines. Histamines
are responsible for allergy symptoms which can range from mild
to severe. Symptoms can affect the gastrointestinal tract (nausea,
stomach cramps, vomiting, diarrhea), skin (localized itching,
hives or rashes, swelling of the lips), and/or respiratory system
(breathing problems). People who already have asthma may be
more likely to have food allergies. Although allergic reactions
are usually mild, some individuals can experience severe symptoms,
like anaphylactic shock, which can cause death.
Allergies to seafood
don't usually go away or diminish with age. In fact, allergic
reactions may become more severe with each subsequent exposure
to the offending food. That's why it's important to recognize
an allergy or have it diagnosed by a medical doctor. The allergy
is managed by avoiding the offending food. There is no cure
for food allergies.
Most allergies are
specific to a certain specie or type of seafood. For instance,
someone who is allergic to finfish, may not be allergic to shellfish
and vice versa. However, if you know for certain you are allergic
to a certain type or specie of seafood, read ingredient listings
on food labels and question restaurant staff carefully before
eating food you suspect contains a potential allergen. Sometimes
very small amounts of the allergen can trigger a reaction. People
who have a history of anaphylactic reactions should carry medication
like epinephrine and know how to self-administer it.
public perception that seafood is not inspected, seafood, like
all other food, is subject to federal, state, and local government
regulations and inspections.
At the federal level,
the FDA is primarily responsible for the regulation of seafood.
The FDA inspects seafood processing plants and imported seafood,
oversees the National Shellfish Sanitation Program, samples
and tests seafood products, and enforces labeling requirements.
The FDA works with the individual states to implement these
Recently, the FDA
has expanded its regulatory program and implemented a new system
for seafood safety control called HACCP (pronounced hassup),
which stands for Hazard Analysis Critical Control Point. Designed
to control potential hazards in food production, HACCP based
systems are already being used by the space program to produce
food for astronauts and the canned food industry. Effective
December 18, 1997, all seafood processors must have HACCP plans
in place and be able to demonstrate it's effectiveness to FDA
inspectors. The U.S. Department of Agriculture is switching
to HACCP regulations in phases for meat and poultry processors
as follows: January 25, 1998 for plants with more than 500 employees;
January 25, 1999 for plants with more than 10 employees; and
January 25, 2000 for plants with less than 10 employees.
State agencies also
conduct regular inspections. In our state,for example, the Georgia
Department of Agriculture inspects and licenses seafood processing
plants, shellfish processors, and distributors, and regularly
inspects retail stores. The Coastal Resources Division of the
DNR monitors molluscan shellfish-growing waters, licenses and
monitors shellfish harvesters, and tests shellfish for chemical
contaminants. The Environmental Protection and Wildlife Resources
divisions of the DNR collect and interpret information about
chemical contaminants in sport fish and other safety concerns,
evaluate health risks, and issue advisories when necessary.
Local health departments also regularly inspect restaurants.
In addition to mandatory
federal and state programs, another federal agency, the National
Marine Fisheries Service, coordinates a voluntary inspection
Changes in the regulatory
system are likely to occur as the public debate on food safety
continues, and both consumers and the seafood industry are likely
to benefit from programs that provide additional cost effective
and practical safety controls.