When you want, or need, to know more than the superficial, such as when you are
where there is no access to a physician.
Prototypically: Medicine at Sea
This medical information is provided for education purposes only. I am making no attempt to practice medicine over the internet. This is being written to give some basic knowledge for those that are physically isolated from access to professional medical care, such as sailors at sea. This is to help in deciding whether an emergent medical condition exists, how to initially deal with it, and whether evacuation is needed. It is by no means exhaustive or meant to replace personal medical attention. Please do not contact me regarding your personal condition. Over the years I have received many emails from people asking for help with their personal chest pain, or whatever. Sometimes they write during acute pain. This is ridiculous. You can't practice medicine over the internet. If I find their email, after it has been filtered by my spam filter, it may be days or weeks later. My response, if any, will be to contact their regular provider. Even a bad doctor in person is better than an email. Please use this information in the spirit in which it is intended.
Sincerely, Mark R. Anderson, M.D.
my other interests
Poisonous Sea Life v.2.4
© Mark R. Anderson, M.D. 2000
Updated Dec. 12, 2004
There are a myriad of sea life poisonings. Some are lethal. Some a mere nuisance. I've chosen to summarize these in order from most 'primitive' species to more complex.
This information is not meant to be exhaustive. It is, however, intended to provide enough information for the laymen who needs it to determine what the risks are. In addition, advice on prevention, first aid and when to seek help is included.
Coelenterates include sea anemones, hydroids, hard and soft corals and free swimming jellyfish. These invertebrates sting by injecting the victim (usually fish) with a dart-like barb that shoots out from its coiled position in a venom sac. Each jellyfish has thousands of these. This is why sea anemone tentacles feel somewhat sticky. It's fortunately primarily some jelly fish that can penetrate skin enough and be toxic enough to be a real problem. There are also anemones that can significantly sting. Symptoms are immediate burning pain followed by red or violet welts that may be in lines along where the tentacle contacted the skin. Severe stings may later ulcerate the skin followed by slow healing. Severe asthma-like attacks can occur along with cardiovascular collapse. Delayed rashes and joint pains and even blurred vision have occurred. The nematocysts aren't very big, so wearing clothing while swimming will provide some protection.
If stung, the first action, after removal for the water, is to inactivate the stinging apparatus, (nematocysts). I've read confliction literature regarding this. Some recommend alcohol. Others, e.g. Goldfrank, states that alcohol may actually discharge nematocysts and should be avoided. Vinegar is commonly recommended. Even urine has been recommended. Vinegar is supposed to help with Portuguese Man-O-War stings, but some say will aggravate Sea Nettles. Nettles respond best to baking soda. If tentacles remain attached to the skin, cover them with shaving cream, baking soda or flour. After a few minutes, a dull edge (e.g. a credit card) can be scraped along the skin to dislodge the tentacles. A meat tenderizer paste may also be helpful, but shouldn't be used on anyone allergic to papaya. A meat tenderizer wet paste applied promptly can osmotically remove toxin, (as can a salt paste) but the meat tenderizer (which contains the enzyme papain) breaks down the protein components of the toxin. Persistent pain may respond to immersion in hot water, e.g. 110-115 deg. F. for a half hour. Antihistamines may help.
Portuguese Man-o-war (Physalia)
These pale blue, bell-shaped jellyfish that have a sail along the top are common in Florida and the Gulf of Mexico. Tentacles may be almost invisible and trail as much as 10 ft. (3.3 m) from the body. Others say 100 ft.. Stay clear. Tentacles detached from the body by waves are still capable of stinging for up to three months. They are quite toxic and deaths have occurred if a victim receives multiple stings.
Sea wasp or Box jellyfish (Chironex)
This is the most deadly and venomous of all stinging marine life. It's usually in Australian and SE Asian waters but can be found in open ocean. Each jellyfish has enough venom to kill several adults. The overall fatality rate is as high as 20% of those stung and due to low blood pressure, muscle spasm, respiratory paralysis or cardiac arrest. Death can occur within 30 seconds of envenomation. Similar, but less deadly species include Chiropsalmus and Carybdea. Australia is certainly the most dangerous area for these stings. An antivenin is available.
Fire coral (Millepora)
This is not a true coral, but rather a hydra. It is often misidentified as a seaweed. The burning and welts are the same and the treatment is the same. Welts may last for several weeks and leave a pigmented scar.
Echinoderms include sea urchins, starfish and sea cucumbers. Most starfish are not venomous. The exception is the Crown of Thorns (Acanthaster planci). Incapable of attacking, a careless brush against it causes many deep painful punctures. Envenomation may lead to vomiting and paralysis. It's found throughout the IndoPacific.
Sea urchins sometimes have venom glands at the ends of their spines and their tiny feet (pedicellariae). Poisoning can lead to vomiting, cramps, red swelling, numbness, incoordination, fainting and breathing difficulties. A more typical problem though are the punctures themselves. Some urchins have thin brittle spines a foot long. They may penetrate deeply and break off deep in muscles or even inside joints. Nasty infections can develop. Joint infections can destroy the joint.
Punctures and venomous stings from crown of thorns starfish and sea urchin stings, are likely to be helped by hot water, (as hot as can be tolerated without scalding) for up to 90 min. or more. Whether to remove embedded spines depends on location, evidence of infection or persistent pain. This can be complicated surgery. Bits close to the skin will likely pus out as an abscess forms and then drains. Any puncture wound demands up to date tetanus immunization. The tetanus bacterium has been found in sea water. A tetanus booster every ten years is considered adequate for general protection, but a booster should be given after five years if the wound is a deep puncture, contaminated with dirt, or a crushed or very jagged wound.
Sea urchins can also be toxic by ingestion. They are considered a delicacy in the Caribbean and the Orient. The gonads are the toxic part and can cause excess salivation, abdominal pain, vomiting and diarrhea. Some people also eat starfish which has been reported to cause vomiting.
Mollusks include gastropods (snails), pelecypods (clams), scaphopods (tusk shells), and cephalopods (octopi, squid and nautili), chitins and sea slugs.
Shellfish allergy is one of the more common true food allergies. True allergy symptoms include hives (raised itchy red welts that form over large areas of the body that tend to change over a period of minutes to hours), swelling that develops around the eyes and lips, swelling of the throat (possibly leading to difficulty swallowing or even breathing), and wheezing shortness of breath. Hives are very irritating but it's the throat and breathing symptoms that can get severe enough to even endanger your life. The severe reactions usually develop within an hour or so of eating the food. Hives can develop hours to a day later. The severe reactions are treated with adrenaline (Epinephrine) injections, antihistamines and steroids such as predisone. The adrenaline is most important in a life-threatening situation.
There are many types of bacterial food poisonings that can be caused by eating shellfish, (particularly clams), especially if they are eaten raw. Generally these "poisonings" are not true toxins but rather infections caused by ingesting these bacteria live. They generally cause a gastroenteritis syndrome such as vomiting, cramps, and diarrhea. Treatment is prevention of dehydration, a clear liquid diet and possibly antibiotics. Antibiotics are more likely to be needed if there is bloody diarrhea.
There are several varieties of serious shellfish poisonings. These are generally due to clams that have become poisonous due to their life style as filter feeders. They filter out and concentrate plankton that are toxic. The plankton cause the famous red tides when they bloom in extreme cases. Don't trust your eyes as to whether toxin is present.
Paralytic Shellfish Poisoning (PSP). This is a true toxin that is concentrated in the flesh of filter feeding marine life, such as clams. The toxin comes from certain dinoflagellate plankton, (Protogonyaulax sp.) that are more likely to overgrow in the summer months. The toxin is heat stable, i.e. it is NOT destroyed by cooking. Your only way to know whether it is present is by lab testing followed by health or fisheries department posting of shellfish beds. Some clams retain the toxin in their flesh and remain poisonous for up to 2 yrs. after they feed on the plankton. Symptoms range from mild tingling, that may occur as early as 30 min. after ingestion, up to paralysis and death by being unable to breathe. Deaths that occur are usually within the first 12 hours. Gastrointestinal symptoms are less common. Vomiting should be induced at the onset of early symptoms, (to get any remaining shellfish out of the stomach), followed by prompt medical attention because the victim may need to be put on a respirator if the poisoning turns out to be severe. Prevention is the key. The early time to onset of symptoms, around 30 min., is a clue to the diagnosis.
Neurotoxic Shellfish Poisoning (NSP) is usually due to Ptychodiscus brevis (formerly Gymnodinium) concentration.. It is similar to, but distinct from PSP. The time to onset is usually around 3 hrs. (range 15 min. to 18 hrs.). Tingling and other sensory changes occur such as hot and cold temperature reversals. In addition there may be muscle aches, vertigo, clumsiness, abdominal pain, vomiting, diarrhea, headache, shakes, difficulty swallowing, slow pulse and dilated pupils. The GI and nerve symptoms start together and last from 1 to 72 hrs. Treatment is supportive. Respiratory difficulty is rare. Brevitoxin is also heat stable. It can also lead to cough and wheezing, which has been known to occur by toxin getting into the air from wave action along the beach during red tides.
Then there is Amnestic Shellfish Poisoning (ASP). This is caused by domoic acid, concentrated in clams feeding on the plankton Nitzschia pungens. It can also affect crabs by being concentrated in their gills so avoid eating crab internal organs, which some recipes call for and is common in Asian cultures. Symptoms are often delayed around 5 hrs. (15 min. to 38 hrs.) and consist 1st of GI symptoms, possibly followed by confusion, coma, seizures, and shock from low blood pressure and slow heart rate. Death can occur at a rate of about 2% (generally in the elderly) and there can be permanent brain damage. Ten percent of victims suffer long term memory problems and/or muscular and sensory problems. Treatment is supportive only. The toxin is not as heat stable as the PSP toxin but, again, is NOT adequately destroyed by cooking. A major outbreak occurred in Canada in 1987 from commercially cultivated mussels on Prince Edward Island. The poison has also been found in Pacific NW waters since 1991. Regular monitoring is now done.
Japanese shellfish poisonings:
There are several types of poisonings that have been found in Japan. Oyster poisoning caused by venerupin from plankton has a high fatality rate. Callistin poisoning causes an allergic type reaction. Adalone poisoning comes from Japanese seaweed and causes a rash triggered by sunlight. Red whelk poisoning causes paralysis and is frequent in Japan.
Naturally poisonous mollusks:
The shellfish poisonings discussed above are due to a toxin getting into the shellfish. There a few mollusks that are naturally very poisonous. The Blue-Ringed Octopus (Hapalochlaena maculosus) is a mollusk, a cephalopod and is quite poisonous. It contains tetrodotoxin (see Fugu poisoning) and at least 8 other toxins. Symptoms include burning, numbness, local loss of blood supply, and spreading nerve symptoms that can lead to difficulty swallowing or speaking, blurred vision, coma and cardiovascular collapse or respiratory failure. Treatment is supportive and likely to require intensive medical care. Hot water to the bite doesn't help.
Cone shells (Conidae) are tropical snails that generally live in shallow waters in and around coral reefs. They are very attractive and may sell for large sums. There are approximately 400 species, and 18 have been reported venomous. About 6 species are especially toxic. Conus geographicus can get up to 6 in. long and is very toxic. A few deaths have been caused by cone shells, but death from envenomation is not common.
The venom apparatus is a long thin proboscis that can be extended several inches from the narrow end of the cone, adjacent to the siphon that is thicker and also extends from that end. The proboscis is very flexible and muscular so it can bend around in all directions. Inside the body of the snail, in a muscular venom bulb, are stored a 'quiver' of radular teeth that are tiny hollow harpoons. When the cone is about to strike, a tooth is transferred to the end of the proboscis. Venom is forcefully injected through the tooth. I think the tooth stays in the victim. I believe it to be made of calcium carbonate so it would show up on detailed xrays as a thin line several mm in length.
Since the proboscis comes out of the narrow end of the cone shell, it's safest to pick them up by the fat end. If the proboscis bends around to strike, a strike into a fingertip would be common. The snail doesn't have eyes on the proboscis so it can't really be aimed, such as to preferentially go under the fingernail. All live cone shells should be considered potentially venomous and should be picked up wearing thick gloves.
As to symptoms, the venom is a neurotoxin. There would be immediate local pain like a wasp sting followed by local redness and swelling, which usually resolves within an hour. Either loss of sensation, or hypersensitivity can follow, along with blue discoloration from poor blood supply to the area. Swelling can last several weeks. Serious cases cause general muscle weakness, paralysis, hoarse voice, difficulty swallowing, double vision, slurred speech and difficulty breathing. There may be nausea but not generally other gut symptoms. Symptoms usually resolve within 6-8 hrs. but respiratory support may be needed. The rare deaths are caused be respiratory arrest.
Treatment should be immediate immersion in hot (110-115° F) water for 30 minutes. Usually symptoms resolve within an hour but observation for severe symptoms should be done for several hours. Rarely is ventilatory support needed. I know of no antivenin available.
Stonefish and other bony fish with poisonous spines
Venomous punctures and stings from scorpaenidae fish such as stonefish (Synanceja horrida), catfish, and Pterois sp. (scorpion, surgeon, lion, turkey, zebra, and tiger fish), are likely to be helped by hot water, (as hot as can be tolerated without scalding) for up to 90 min. or more. These fish are found in the Gulf of Mexico, Pacific and Indian oceans.
Generally punctures from the spines of these fish cause severe burning pain and swelling within seconds. Stonefish can also cause severe cardiovascular collapse. The stonefish is known to prefer to attack humans rather than swim away. (Nasty bugger isn't it?) The pain can be so severe as to cause the diver to lose consciousness, and then it intensifies for several hours! Early systemic symptoms include vomiting, sweating and passing out. Later severe reactions include heart irregularities, angina (heart pain), trouble breathing from fluid seeping into the lungs, convulsions and paralysis may develop. Obviously, aside from promptly applying heat, you should get the victim to prompt medical attention. Again consider a tetanus booster.
The weeverfish lives in muddy and sandy bottomed bays in the temperate waters of the eastern Atlantic, Mediterranean and European coastal waters. It's a small (10-50 cm) fish that burrows into the bottom leaving only its head exposed. Problems occur when stepped upon. The sharp spines are capable of penetrating a leather boot. There's immediate burning or crushing pain that increases and spreads up the leg. the area becomes red, swollen and later black and blue. The swelling can involve the entire limb and last for months. Systemic symptoms can also develop, including shock and seizures.
Stingrays are generally peaceful bottom feeders. Nevertheless, about 1800 ray envenomations occur annually in the USA, generally by being accidentally stepped upon. Eleven species occur in the USA. They have a tail barb that reflexively jabs anything it contacts. Flesh is easily penetrated and significant lacerations can result. Stingrays inject a toxin that breaks down with heat. For the initial wound, let it bleed freely and wash it out with sea water. Remove any visible debris. Wash it out some more with clean water. Then apply the heat at 110-115° F.
A large and diverse group of bacteria can infect these wounds. Vibrio sp. (and V. vulnificus in particular) infections should be covered by antibiotic treatment. Third generation cephalosporin type antibiotics are generally considered appropriate for these infections. Oral antibiotics of this group include cefixime (Suprax) and ceftibuten (Cedax). A common injectable antibiotic of this class is ceftriaxone (Rocephin). None of these are routine or cheap antibiotics. They should be reserved for infections and not used prophylactically. The cleanliness of these wounds is most important to minimize the substantial risk of infection.
The toxin affects nerves, vessels and circulation. Pain is out of proportion to the degree of injury. The wound may become blue or gray and then later red, black and blue and finally some tissue may die. Systemic symptoms, if they occur, include cramps, weakness, shakes, passing out, collapse from low blood pressure, paralysis and even convulsions.
Ciguatera fish poisoning is caused by a toxin from a dinoflagellate plankton that is concentrated up the food chain. The specific toxic plankton is not always present so whether a fish will be toxic or not varies with time. Free swimming pelagic fishes aren't a problem, but those that feed on reef fish may be, if the plankton is present. Symptoms begin between 2 and 30 hrs. after ingestion, (average around 6 hrs) and in 2/3 of people begin with vomiting and/or diarrhea. This is actually beneficial in that it helps your body clear itself of the toxin. This is followed by the nerve symptoms, e.g. sensory changes, weakness, burning sensations, muscle aches. There may be the peculiarity of hot objects feeling cold and vice versa. Neurologic symptoms can be severe. Fortunately it is not as often fatal as it used to be. Fatalities occur due to respiratory failure. Adequate medical care can support breathing until symptoms subside. This is probably why there have been no documented ciguatera deaths in the U.S.A..
Treatment is usually supportive. IV mannitol has been found to reduce neurologic and muscular symptoms but not affect the GI symptoms. It is self-limited, but can take months or even years before all symptoms resolve. Usually, however, the symptoms subside over several days.
Moral: Eat lower on the food chain and/or get local knowledge. There is now a test kit (CiguaCheck) that is available for home use, but I've no experience with it.
There are folk tests for Ciguatera, but they're probably all useless. This is similar to the various 'tests' for poisonous mushrooms that are known to be useless. In any event, supposedly 'natives', (I know not where), have noted that if the fish is cooked with coconut, the coconut will turn black if the fish is toxic. (Source: "Michael on s/v Lookfar" in Cruising World, Feb. 2000, pg. 8) Some believe that if the fish is cooked with silver, the silver will turn black in the presence of poison. This is known not to be reliable. Yet, there you are, use these 'tests' at your own risk. I wouldn't trust them.
Over 500 species have been reported toxic at one time or other. Here's a list of those most commonly affected.
Sea Bass, especially. Grouper, Snapper, Jack, Barracuda, Moray Eel
Parrotfish, Surgeonfish, Triggerfish, Filefish, Porgie
This type of fish poisoning is due to spoilage of fish that have a high content of histidine in their dark meat. It was originally described in fish belonging to the the Scombroidei suborder which includes tuna, bonito, mackerel, and albacore. Actually, those most commonly affected are nonscombroid fish such as mahi mahi and amberjack. The bluefish of New England has also been implicated. Inadequate refrigeration allows marine bacteria to interact with the histidine in the flesh of the fish and turn it into histamine and saurine, the chemicals responsible for the symptoms. Saurine, by the way, is a name derived from saury, a Japanese dried fish delicacy that often causes poisoning. These chemicals are heat stable so cooking won't destroy the toxin. Since the toxin is the result of spoilage, scombroid poisoning is completely preventable.
The fish MAY taste sharp, pungent or peppery. Symptoms usually develop within minutes, but may delay several hours. They are: intense headache, dizziness, numbness or burning of the mouth, pain or difficulty swallowing and abdominal pain, nausea, vomiting. This is followed by flushed red skin and possibly itching and hives. Swelling may occur, e.g. of the face, along with other allergic type symptoms such as itchy red eyes and nasal congestion. Wheezing may present as acute asthma. Death is rare, and symptoms pass within a day, generally with improvement within a few hours.
There actually is some treatment for this poisoning. Since the symptoms can occur quickly, there may be some benefit from emptying the stomach by inducing vomiting. For this to be worthwhile, vomiting should occur within an hour or so of ingestion. The symptoms aren't due to allergy to the fish, but they resemble allergy because the cause is the histamine, which is also the main chemical intermediary in most allergies. Therefore, you can reduce symptoms by giving H1 type antihistamines, such as chlorpheniramine (Chlortrimeton), diphenhydramine (Benadryl), dimenhydrinate (Dramamine), and promethazine (Phenergan). Antihistamines will work the best if they are injected. Possibly beneficial would be the H2 blockers such as Tagamet, Zantac, Pepcid, and Axid. If there is swelling threatening the victim's airway, or wheezing, then an injection of epinephrine (Adrenalin), and steroids such as prednisone should be given. Also useful would be asthma inhalers such as albuterol.
Assuming that more than one individual is affected by eating the same fish, they can be assured that they are not allergic to fish. If only one person is affected, the diagnosis is somewhat uncertain.
Avoidance: Don't eat tuna and similar species that isn't freshly caught and/or adequately refrigerated.
Other causes of acute flushing due to food include: acute allergic reactions (most common to nuts, eggs, milk, fish, shellfish and peanuts), MSG (Chinese restaurant syndrome, Accent), metabisulfites (preserved wine, salad bars, fruit juice), tyramine (wines, aged cheeses, MAO type antidepressant medications), tartrazine (yellow food coloring and food additives), alcohol (especially certain genetically predisposed Asians and Native Americans).
This serious poisoning is due to improper consumption of puffer like fish such as globe, balloon, blow and toad fish. The toxin has also been found in the blue ringed octopus and in some newts and salamanders that have bright colors and rough skins, in particular the Taricha granulosa found from California to southern Alaska. The toxin is heat stable and mainly in fish skin, liver, ovaries, intestines and possibly muscle.
Symptoms typically occur within minutes. Headache, sweats, numbness and tingling evolves rapidly. Then difficulty swallowing and speaking, vomiting and abdominal pain. Generalized weakness, incoordination, twitching muscles and a progressive paralysis leading to respiratory failure occurs within 4-24 hrs. Death rates may approach 50%.
Treatment is supportive and obviously requires medical facilities.
Other types of fish poisoning
Filefish form aluterin, which causes vomiting and diarrhea. Herring, sprat, sardines and tarpon may contain clupeotoxin which also causes gastroenteritis and neurological symptoms. Ratfish, elephantfish and chimeras may cause decreased level of consciousness. Gemblid poisoning, from snek, mackerel and caster-oil fish causes dramatic purging. Mullet, goatfish and rudderfish can cause hallucinations. Japanese mackerel (sawara) and sea bass (ishingh) and sandfish can be poisonous.
Lampreys and hagfish can cause cyclostome poisoning with GI problems. Their cheek secretions have an anticoagulant toxin that is not destroyed by cooking. Soaking the fish for several hours in brine may reduce the toxicity. The Sea Lamprey (Petromyzon marinus) and the River Lamprey (Lampretia fluviatilis) are considered poisonous. The Sea Lamprey is found on both sides of the Atlantic. The River Lamprey is found in the Baltic Sea, the North Sea, Ireland and France and the rivers into those seas.
Sea snakes occur in the Pacific and Indian Oceans, especially along the coast of SE Asia, in the Malay Archipelago and the Persian Gulf. About 50 species exist, all toxic, of which seven may be fatal to humans. Most are 3-4 ft. (1-1.5 m) long. occasionally longer. No sea snakes live in the Atlantic or Caribbean. Fortunately the majority of these snake bites do not inject toxin because their fangs are short and easily dislodged. Symptoms of envenomation are primarily neurological and develop 3-6 hrs. after the bite. Symptoms may be local or systemic and can include paralysis, respiratory failure, muscle breakdown and kidney failure.
Treatment is primarily stabilization and observation. If there are signs of envenomation, a polyvalent sea snake antivenin (Commonwealth Serum Labs, Melbourne, Australia) can be administered.
Various other rashes and itches can occur after swimming that are collectively called 'swimmer's itch'. There are many causes of this due to microbes, plants and animals. Specific diagnoses include fungal and bacterial infections, sponge poisoning, various coelenterate stings, stinging seaweed (e.g. the blue-green algae M. lyngbyaceus), and others. If you can't figure it out, start by treating the symptoms, e.g. with antihistamines for itching and try to get further medical advice.
This dinoflagellate is causing problems in parts of the Chesapeake Bay. It, and related organisms, have been found all along the SE coast of the USA. There appear to be about 24 life-cycle stages of this organism, some of which are toxic. There has been confusion and conflicting information about what causes what. Reported have been fish die offs, unusual skin lesions on fish and a variety of human complaints thought to be caused by exposure to contaminated water. At the present time, consumption of contaminated sea food is not thought to be causative. Toxins are released into the water when Pfiesteria undergoes a 'bloom' under certain conditions of environmental nutrients. The toxin only lasts for a few hours in the water, though the evidence of its presence, e.g. fish kills, may last for weeks. Human symptoms appear to be caused directly by the toxin. It could be absorbed through the skin, ingested or aerosolized and inhaled. Human complaints include headaches, memory and learning difficulties, rashes, diarrhea and weight loss. The most consistent complaints are a burning sensation of the skin and cognitive difficulties. The human syndrome is called Pfiesteriosis. There is no specific treatment, but it is self-limited, with symptoms resolving within weeks.
There is evidence that water pollution, such as agricultural runoff, may influence the dinoflagellate's life cycle, trigger blooms, and may be why a previously benign organism is now causing problems. Since these conclusions may affect the business of farming, the entire issue has become a political.
Cohen, M.D., Michael Martin , Dr. Cohen's Healthy Sailor Book,, International Marine Publishing Co., © 1983.
Ellenhorn, Matthew J. &Barceloux, Donald G., Medical Toxicology, Diagnosis and Treatment of Human Poisoning, pub'd by Elsevier, © 1988.
EPA Pfiesteria Fact Sheet, http://www.epa.gov/owow/estuaries/pfiesteria/fact.html
Goldfrank , Lewis R., et al, Goldfrank's Toxicological Emergencies, 5th ed., © 1994
Infectious Disease News, Human effects of Pfiesteria remain a mystery, http://www.slackinc.com/general/idn/199906/pfiester.asp
Morris Jr., Glen, Lancet, Dead Fish, Estuarine Water, and Mental Difficulties, August 15, 1998, pp. 532-39.