RECREATIONAL

SEAFOOD SAFETY

A Guide for Marine Recreational Fishing

"Most seafoods available tothe U.S. public are urholesomeand unlikely to cause illness inthe consumer."

� institute of MedicineNational Academy of Sciences

Report of Seafood SafetyMay 1991

Seafood SafetyA Guide for Marine Recreational FishingCover photo by R. Epstein

Design ck Layout byDenise M. Prodigo

Publication Date:

September 1991

CONTzm s

8-9

.1G

.11

13

Introduction. 2

Seafood Health Risks in

Perspective . .............3Consumption of Raw Seafoods

Eating Raw Fish or Shellfish.........4-7Seafood from Specific Locations

CigiiateraTetrodo toxin.

RedTide

MishandlingScombroid Poisoning. 12Cross-Contamination of Ready-

To-Eat Seafood.

Chemical Pollutants

Recreational Health Risks.........14-15

Maintaining Quality in the CatchHandling. ...................16-17Cleaning. ....17Icing.....................................18-19

Contacts for Additional

Information.

Recreational Seafood Safety waswritten by:

Dr. Steven Otwell

Sea Grant Seafood SpecialistFood Science and Human Nutrition Dept.University of FloridaGainesville, Florida

Frank Lawlor

Sea Grant Extension AgentPalm Beach County Extension OQicePalm Beach Gardens, Florida

creational fishing produces asignificant portion of all the edible fishand shellfish harvested annually in Flor-ida. Current estimates by the NationalAcademy of Sciences suggest the nation-wide recreational catch co@tributes

more than 20 percent of the annualamount of' seafoods consumed in the

United States. These estimates em'pha-size the importance of protecting b&hthe quality of the catch and the qualityof our inland and coastal waters.

Sport-caught seafoods from marinewaters offer many noted nutritionalattributes, The basic benefits of highquality, easily digested protein and lowfat content are accompanied by a fullcomplement of minerals, vitamins andthe unique, healthful omega-3 fatty ac-ids. Recent studies have linked seafood

consumption with a variety of healthbenefits including decreased risk fromcardiovascular disease. These benefits

further enhance the enjoyment of recrea-tional fishing.

The vast majority of recreationallycaught seafoods are wholesome and safeto eat. Nevertheless, as for aH foods,there are some health risks associated

with consumption of certain types fromcertain locations, and there is thechance that mishandling of the catchcan create a health risk. The intent of

this brochure is to outline some of thy,more problematic concerns in order toavoid and prevent seafood-borne ilknesses from the recreational ca~ in

Florida. Likewise, this advjee sold en-courage concern for m@inkai9ieg thsv~quality of Florida's water..

SEAFOOD HEALTH RISKS

IN PERSPECTIVE

Through the last decade, reported ill-nesses from seafood consumption have aver-aged less than 10 percent of all the types ofreported foodborne illnesses. In 1989, theCommissioner for the U.S. Food and Drug Ad-ministration stated, "...fish is by far the saf-est source of muscle protein available."When problems do occur, they are usuallycaused by contaminants present prior to cap-ture or due to mishandling of the catch. Forthese reasons, a significant portion of the an-nually reported seafood-borne illnesses in-volve a recreational catch and/or at homepreparation.

Illnesses associated with seafood

consumption can be grouped intofour general categories:

~ consumption of raw seafoods,~ eating certain types of seafood

from certain locations,~ mishandling, and~ chemical pollutants.

Avoidance and prevention of these prob-lems require common sense and awareness ofthe potential causes.

CONSUMPTION OF

Eating raw 6sh or sheHfish is themost frequent cause of seafood-borne ill-nesses. These raw foods carry bacteria andother contaminants that may be harmful toconsumers. This eating preference is of par-ticular concern for consumers with healthconditions that impair their health defensesystems.

Live oysters and clams filter enormousamounts of water to obtain food. This samewater may contain potentially harmful typesand amounts of bacteria and virus that canconcentrate and survive in the shellfish. Mis-handling of the recreational harvest can fur-ther contribute to the growth and survival ofbacteria.

Similarily, some live fish can carry para-sites which are part of the natural ecology ofthe marine environment. In most instancesthese marine parasites are not harmful to hu-mans and are simply destroyed by human di-gestion. Although the occurrence of a marineparasite infection in humans from eating rawfish is very rare, the unpleasant thought ofeating a parasite is enough reason for caution,

Raw oysters are delicious, bvt they can containharmful bacteria.

RAW SEAFOODS

tl I ll RIP~

R APPAOVED

Rl PROHIBITED

H CONDITIONALLY APPROVED/

C p

The Florida Department of Natural Resources des-ignates waters that are "approved" for shellfish har-vesting. By restricting shellfish harvesting to theseareas, the quality and purity of the product can begreatly enhanced for consumers.

CONSUMPTION OFQ�m' x::cA/AO: . a>@;jki~,.'

Live shellfish, clams and oysters shouldonly be taken from 'approved' coastal waters, Acontinuous coastal water monitoring and approvalprogram is conducted by the Florida Departmentof Natural Resources FDNR!. Advice and mapson "approved shellfish waters" are available fromlocal FDNR offices or cooperating city and countyhealth departments. Approved waters apply toall clams and oysters whether they are to be eatenraw or cooked, and also apply to scallops if theyare to be eaten raw and whole viscera and mus-cle!.

Consumers with compromised health condi-tions that impair their health defense systemsshould not eat raw shellfish! Despite regulatorymonitoring and approval of waters, certain bacte-ria which can infect compromised consumers maybe present on raw oysters or clams, One exampleis Vibrio v ulmficus which has caused death in con-sumers who are in the so-called 'health risk cate-

gories,' These bacteria are easily destroyed bythorough cooking.

All raw shellfish must be stored in refrigera-tion to slow or minimize bacterial growth. Directstorage in ice is not recommended as it may kill

RAw SEAFoODS

the shellfish. Dead shellfish, those that remaingaping open even when tapped, should not beeaten. Live shellfish have a better flavor and less

chance to cause illness. The recommended stor-age for live shellfish is 'indirect' icing in a cooleror box with insulation towels, paper! that pre-vents direct contact with the ice. While the melt-

ing ice provides an essential moist atmosphere,the shellfish should not be exposed or immersedin the melted water. Freshwater exposure cankill marine shellfish.

Some ra~ marine fish can contain para-sites often called 'worms' or 'cysts,' Those visibleabout the gut or surface of the fish muscle can beeasily removed with a knife. Ones that are not re-moved are easily destroyed by customary cooking.

An added safety measure for consumers desir-ing raw fish or sushi is to place the seafood in fro-zen storage ideally below O' F for at least 48hours prior to serving!. This technique kills theparasites. Much of the desired raw fish qualitycan be retained by rapid freezing methods such aspacking fillets in a thin, 1-inch layer and then lay-ing them in frozen storage with ample cold air ex-posure. Frozen fillets should be slowly thawed inrefrigeration �2-38'F!.

t health defense systems include:

~ any person receiving immunosup-pressive drugs

~ steroid dependency as used forconditions such as chronic

obstructive pulmonary disease!,~ achlorhydria a condition in

which the normal acidity of thestomach is reduced or absent!,and

~ medicines thai reduce stomachacid.

SEAFOOD FROM

Ciguatera is a form of seafood poisoningcaused by natural toxins that can occasionally befound in certain marine fish from specific tropi-cal reef waters. The natural toxins are formed bymicroplankton and accumulate in the food chain.Potentially any tropical marine fish participatingin a food chain with ciguatoxin could becomeciguatoxic, but documented illnesses and some re-cent analyses indicate some fish are more sus-pect, In the Caribbean region, the fish with theworst reputations are � amberjacks and otherjacks, moray eels and barracuda. Other fish withconcerned reputations are hogfish, scorpion 6sh,certain triggerfish, and some snappers and grou-pers.

Because of their feeding habits, barracuda arelikely to be ciguatoxic and should not be eaten.

SPECIFIC LOCATIONSCiguatera is most common in certain true

tropical reef areas as in the Caribbean region.Ciguatoxic fish cannot be detected by appear-ance, taste or smell. Raw and cooked whole fish,fillets or parts have no signs of spoilage, discolora-tion or deterioration. The toxins present cannotbe completely destroyed or removed by cooking orfreezing.

Unfortunately, the documentation, verifica-tion and utility of a reliable ciguatoxic fish list isseriously compromised by the diversity of fish spe-cies and variable nomenclature. For example, lo-cal fishermen may refer to a variety of fish as"jacks" or "snappers" when they are actually amackerel, ~mme or other species. Certain spe-cies of snapper and grouper are never implicatedin ciguatera, yet their popular reputation suffersfrom species misidentification.

Selecting smaller fish, which are likely to ac-cumulate less toxin, offers limited guidance dueto variable sizes per species. Particularly largefish of any tropical species from Caribbean reefzones should be avoided, Likewise, barracuda isa reef fish eater that is not recommended for con-sumption.

Learning about potential ciguatoxic areasand fish remains the best method for avoidingthis unusual form of food poisoning. Consumerspurchasing tropical marine fish known to occurabout reef waters should patronize reputabledealers and restaurants. Vacationers and experi-enced recreational fishermen should exercise cau-tion in areas of concern for particular tropicalfish.

SEAFOOD FROM

Pufferlish may contain a potentially lethal toxin.

Puffivfkek P~:v,''"e>'t,>',>'t~ PIP!

Tetrodotoxin can be used in reference to a

rare, but potentially severe illness that can resultfrom consumption of a small group of fish � thepufferfish or so-called blowfish or balloonfish. Cer-tain species of pufferfish have been known to pro-duce this toxin which can be stored in the viscera

or edible muscle of the fish. If consumed, thistoxin can cause a potentially lethal conditionknown as "fugu poisoning" in some oriental coun-tries.

The edible muscle from pufferfish is tastyand many species are eaten, yet most consumersare not able to distinguish the potentially danger-ous vs. safe species. For example, in Floridathere are six to eight species of pufferfish andstudies have shown some of these species can pro-duce toxins. Experience and training are neces-sary to properly distinguish the species. Forthese ~ns, the safest recommendation is donot eat pufferfish caught in Florida.

10

SPECIFIC LOCATIONS

Florida's Red tides are produced by mas-sive ~ewths of certain types of microplanktonthat kill fish and contaminate filter-feeding mol-luscan shellfish like clams. The toxins producedby these plankton are persistent in raw, frozenand cooked forms. Likewise, the toxins can be air-borne in rough coastal surf and if inhaled cancause respiratory and eye irritation.

.I~r';~.:7 ~il'r~"~ Se' fef v�

Do not harvest shellfish or dying fish fromknown regions of red tide. Occurrence is typicallyseasonal spring and early summer! along Flor-ida's southwest coast, yet cases have been re-corded out of season and in nearshore regions ofthe east and Gulf coasts of Florida. Consult re-gional offices of public health and the Florida De-partment of Natural Resources for advisories.Toxic regions will recover after the plankton andtoxins dissipate,

Red tides are caused by the sudden and intensegrowth of thi s and other types of micropiankton,This natural phenomenon can cause serious sea-food quality problems whereverit occurs.

MISHANDLING

Seembeei@ I eisemin gP~owem:

Scombroid poisoning is a type of foodintoxication caused by the consumption ofscombroid and scombroid-like marine fish spe-cies that have begun to spoil with the growthof particular types of bacteria. Fish most com-monly involved are members of the Scombri-dae family tunas and mackerels!, and a fewnon-scombridae relatives bluefish, dolphin ormahi-mahi, and amberjacks!. A few addi-tional species have been implicated, but theyare of less concern relative to popular fish con-sumption. The suspect toxin is an elevatedlevel of histamine produced by bacterialbreakdown of substances in the muscle pro-tein. The potential toxins are not destroyedby freezing, cooking, smoking, pickling or can-ning.

Seem5r @id PeisemimgPPPURAHoR:

Potential scombrotoxic fish belong to aparticular group of species that have begunto spoil due to mishandling after catch.These species should always receive specialcare in handling, washing, and proper icing,refrigeration or immediate freezing to pre-vent bacterial growth and spoilage, Studieshave demonstrated that, depending on theweather and location, toxic histamine levelscan be generated within 12 hours sometimeswithin as little as 2 hours! if the catch is notplaced on ice or refrigerated. Thus, speciesof concern left lying on a warm deck, dock, orbeach are likely to produce histamine andcould cause serious illness.

12

TH@ CATcH

RPA87-To-ZAt Scc fGQ6Concern:

Cross-contamination of ready-to-eatseafoods refers to contamination by bacteriathat, if allowed to grow, could pose a healththreat. Potentially harmful bacteria. cancome from the immediate surroundings,other foods, and/or individuals handling thefoods. The prefix "cross" means that clean orready-to-eat items have come in contact witha surface or food that harbors the harmfulbacteria. A typical example of cross-contami-nation is preparing and storing cooked sea-foods like boiled crab and shrimp in the samecontainer previously used for raw seafoods orother uncooked foods,

Ready-to-eat seafoods should always behandled carefully to reduce any potentialtransfer of bacterial contaminants fromother foods, particularly raw seafoods. Keepraw or live seafoods separate from cookedseafoods. Do not store seafoods in a mannersuch that the raw items could drip or drainon the cooked items during storage or han-dling. Do not package cooked seafoods in thesame materials, boxes, wrapping, etc., as pre-viously used for raw seafoods. Storage tem-peratures must be maintained near orpreferably below 35'F. Do not handle cookedseafoods with knives, towels, cutting boardsor containers that have not been thoroughlywashed after any previous contact with rawseafood s.

POLLUTANTS

waters. The warning concerned the detectionof methyl-mercury in shark muscle at an av-erage level of 1.48 ppm parts per million!while the current federal alert level is 1.G

ppm. This health advisory included guide-lines for the amount of shark certain individu-

als should eat. This recent warning realizedthat the detected level did not warrant undue

alarm. Consumption should simply be lim-ited. This recent warning is typical of numer-ous advisories for marine pollutants aroundthe world. These warnings incorporate a sig-nificant risk assessment to assure consumer

safety.Fishermen should be mindful of future

advisories, carefully distinguishing official re-leases from publicity and local reports. Thestate authority for public health advisories isthe Florida Department of Health and Reha-bilitative Services. These advisories can be

accessed through local, city and countyhealth departments.

Official advisories attempt to account forvariations in contaminants, predicted con-sumption patterns and probable long-termconsequences. Fishermen should not general-ize about advisories on one fish, containinantor area. Contaminated fish from one area do

not imply that the same fish from other areasor other fish in the same area are also con-

taminated. Environmental contamination, interms of seafood safety, is usually a site spe-cific problem.

MAINTAINING QUALITY

Proper handling should begin whenlanding the fish. Always try to minimizebruising caused by contact with hard sur-faces decks, gunwales, etc.!. If possible, apadded surface should be provided in thearea of the boat where the fish are landed.

The fish should be washed immediately,either with a simple hosing down, if avail-able, or by bucket rinses to remove slime andspoilage bacteria. The wash water can beclean seawater. However, the washingshould not be done near harbors, marinas,large boat bilging, or any suspect area.When in doubt, use potable water.

If fish remain exposed to the sun and theair on deck or shore, summertime tempera-tures and solar insulation can cause qualityproblems in less than one hour. However,simply chilling seafood can prevent qualitydeterioration and reduce the health riskswhich can result from elevated tempera-tures. Proper icing can be accomplished witha little advance planning and some relativelyinexpensive equipment.

The most effective chilling method avail-able to recreational anglers on a one-day tripis the use of a brine slush solution. This is

simply made by adding clean sea water to ice

eilual portions by weight! in a water proofcontainer. Immediately after washing, thefish alive or dead! should be immersed inthe brine slush and kept there until ready todress at the end of the trip!. Care should betaken when making up the brine slush toavoid using sea water contaminated with oil,fuel or dirt and slime. The slush should be

checked periodically to ensure it still con-tains ice.

Cleaning:

Clean fish as soon as possible after catch-ing them. Scientists say that fish tissue is al-most sterile but the skin surface and viscera

contain many types of bacteria. The skinslime and viscera also provide food for bacte-rial growth. Avoid rough treatment whilecleaning the fish. Gouges or wounds in theflesh are openings which may allow thespread of bacteria. Gut the fish with asmooth, not excessively long, belly cut andleave no blood or viscera in the body cavity.Thoroughly wash all cleaned fish and ice im-mediately with fresh, clean ice. Do not dipcleaned fish in the original brine slush. Donot immerse cleaned fillets in a prolongedfreshwater soak which could dilute and re-

duce meat flavor and texture.

MAINTAINING 'QUALITY

Both crushed or flaked freshwater ice

.are good for rapid chilling of cleaned fish.Fish stored in crushed or flakes of ice remain

moist and glossy and do not dry out as fastas fish placed in refrigerated storage withoutice.

Each vessel operator should decide howmuch ice is needed for each fishing trip bytaking into account the length of the trip,water and air temperatures, and as nearly aspossible, the size of catch expected. It's bet-ter to throw out ice than fish at the end of a

trip,

In general, fish stored in coolerswill be well-chilled when:

. three �! inches of ice covers thebottom of the box;

~ fish are laid in the cooler and

mixed with ice, and the contentsare covered with another layer ofice three inches deep.

~ the cooler contains one pound ofice for each pound of fish stored init.

After unloading, throw out all remainingice to prevent bacterial buildup between

For general advice and specific in-formation on harvestable shellfish wa-ters and red tides write:

Florida Department of Natural ReeourcesShellfish Environmental Asemsment SectionMail Station 205

3900 Commonwealth Blvd.

Tallahassee, FL 32399

For information on obtaining publichealth advisories from state agenciesand locaVcounty health programs, write:

State Health OfhceFlorida Dept. of Health 4 Rehabilitative Services1317 pinewood Blvd.

Tallahassee, FL 32399-0200

Edueatienel Imformetien:

For general advice and related pub-lications, contact your local county ex-tension office or write:

florida Sea Grant College PmgramBuilding 803, Rm.4University of FloridaGainesville, FL 32611-0341