Amnesic shellfish poisoning

Amnesic shellfish poisoning (ASP) is an illness caused by consumption of the marine biotoxin called domoic acid.[1] In mammals, including humans, domoic acid acts as a neurotoxin, causing permanent short-term memory loss, brain damage, and death in severe cases.

This toxin is produced naturally by marine diatoms belonging to the genus Pseudo-nitzschia and the species Nitzschia navis-varingica.[2] When accumulated in high concentrations by shellfish during filter feeding, domoic acid can then be passed on to birds, marine mammals, and humans by consumption of the contaminated shellfish.[3][4][5][6][7][8][9][10]

Although human illness due to domoic acid has only been associated with shellfish, the toxin can bioaccumulate in many marine organisms that consume phytoplankton, such as anchovies and sardines. Intoxication by domoic acid in nonhuman organisms is frequently referred to as domoic acid poisoning.

Symptoms and treatment

In the brain, domoic acid especially damages the hippocampus and amygdaloid nucleus.[1] It damages the neurons by activating AMPA and kainate receptors, causing an influx of calcium. Although calcium flowing into cells is a normal event, the uncontrolled increase of calcium causes the cell to degenerate.[11] Pulido (2008).[12]

Gastrointestinal symptoms can appear 24 hours after ingestion of affected molluscs. They may include vomiting, nausea, diarrhea, abdominal cramps, and haemorrhagic gastritis. In more severe cases, neurological symptoms can take several hours or up to 3 days to develop. These include headache, dizziness, disorientation, vision disturbances, loss of short-term memory, motor weakness, seizures, profuse respiratory secretions, hiccups, unstable blood pressure, cardiac arrhythmia, and coma.

People poisoned with very high doses of the toxin or displaying risk factors such as old age and renal failure can die. Death has occurred in four of 107 confirmed cases. In a few cases, permanent sequelae included short-term memory loss and peripheral polyneuropathy.

No antidote for domoic acid is known, so if symptoms fit the description, immediate medical attention is advised. Cooking or freezing affected fish or shellfish tissue does not lessen the toxicity. Domoic acid is a heat-resistant and very stable toxin which can damage kidneys at concentrations that are 1/100th of those that cause neurological effects.


ASP was first discovered in humans late in 1987, when a serious outbreak of food poisoning occurred in eastern Canada.[1][13] Three elderly patients died and other victims suffered long-term neurological problems. Because the victims suffered from memory loss, the term "amnesic" shellfish poisoning is used.[14] The story made front-page newspaper headlines.

Epidemiologists from Health Canada quickly linked the illnesses to restaurant meals of cultured mussels harvested from one area in Prince Edward Island, a place never before affected by toxic algae. Mouse bioassays on aqueous extracts of the suspect mussels caused death with some unusual neurotoxic symptoms very different from those of paralytic shellfish poisoning toxins and other known toxins. On December 12, 1987, a team of scientists was assembled at the National Research Council of Canada laboratory in Halifax, Nova Scotia. Integrating bioassay-directed fractionation with chemical analysis, the team identified the toxin on the afternoon of December 16, just 4 days after the start of the concerted investigation.[15][16]

Possible animal effects

On June 22, 2006, a California brown pelican, possibly under the influence of domoic acid,[17] flew through the windshield of a car on the Pacific Coast Highway. The phycotoxin is found in the local coastal waters.

Since March 2007, marine mammal and seabird strandings and deaths off the Southern California coast have increased markedly. These incidents have been linked to the recent and dramatic increase of a naturally occurring toxin produced by algae. Most of the animals found dead tested positive for domoic acid.

According to the Channel Islands Marine and Wildlife Institute,[18] "It is generally accepted that the incidence of problems associated with toxic algae is increasing. Possible reasons to explain this increase include natural mechanisms of species dispersal (currents and tides) to a host of human-related phenomena such as nutrient enrichment (agricultural run-off), climate shifts, or transport of algae species via ship ballast water."

In popular culture

In the TV series Elementary episode "The Red Team" (original air date January 31, 2013), a witness is intentionally poisoned with domoic acid.

In the "Bad Fish" episode of Get a Life (original air date: February 2, 1992), Sharon and Gus get amnesia after eating bad shellfish, and Chris seizes the opportunity to convince them that they are his best friends.

Domoic acid poisoning may have caused an August 18, 1961 invasion of thousands of frantic seabirds in Capitola and Santa Cruz, California.[19] Director Alfred Hitchcock heard about this invasion while working on his adaptation of the Daphne du Maurier novelette "The Birds" for his feature film The Birds (1963), and asked the Santa Cruz Sentinel for any further news copy as "research for his new thriller."

See also


  1. ^ a b c Clark, R. F.; Williams, S. R.; Nordt, S. P.; Manoguerra, A. S. (1999). "A Review of Selected Seafood Poisonings". Undersea and Hyperbaric Medicine. 26 (3): 175–184. PMID 10485519.
  2. ^ "Archived copy". Archived from the original on 2016-09-17. Retrieved 2012-05-17.CS1 maint: Archived copy as title (link) Nitzschia navis-varingica]
  3. ^ Bates, S. S.; Trainer, V. L. (2006). "The Ecology of Harmful Diatoms". In Granéli, E.; Turner, J. (eds.). Ecology of Harmful Algae. Ecological Studies. 189. Heidelberg: Springer-Verlag. pp. 81–93. doi:10.1007/978-3-540-32210-8_7. ISBN 978-3-540-74009-4.
  4. ^ Bejarano, A. C.; van Dola, F. M.; Gulland, F. M.; Rowles, T. K.; Schwacke, L. H. (2008). "Production and Toxicity of the Marine Biotoxin Domoic Acid and its Effects on Wildlife: A Review" (pdf). Human and Ecological Risk Assessment. 14 (3): 544–567. doi:10.1080/10807030802074220.
  5. ^ Trainer, V. L.; Hickey, B. M.; Bates, S. S. (2008). "Toxic Diatoms". In Walsh, P. J.; Smith, S. L.; Fleming, L. E.; Solo-Gabriele, H.; Gerwick, W. H. (eds.). Oceans and Human Health: Risks and Remedies from the Sea. New York: Elsevier Science. pp. 219–237. ISBN 978-0-12-372584-4.
  6. ^ Lefebvre, K. A.; Robertson, A. (2010). "Domoic Acid and Human Exposure Risks: A Review". Toxicon. 56 (2): 218–230. doi:10.1016/j.toxicon.2009.05.034. PMID 19505488.
  7. ^ Bargu, S.; Smith, E.; Ozhan, K. (2011). "Toxic Diatom Pseudo-nitzschia and its Primary Consumers (Vectors)". In Seckbach, J.; Kociolek, P. (eds.). The Diatom World. Springer. pp. 493–512. ISBN 978-9400713260.
  8. ^ Bargu, S.; Goldstein, T.; Roberts, K.; Li, C.; Gulland, F. (2012). "Pseudo-nitzschia Blooms, Domoic Acid, and Related California Sea Lion Strandings in Monterey Bay, California". Marine Mammal Science. 28 (2): 237–253. doi:10.1111/j.1748-7692.2011.00480.x.
  9. ^ Lelong, A.; Hégaret, H.; Soudant, P.; Bates, S. S. (2012). "Pseudo-nitzschia (Bacillariophyceae) Species, Domoic Acid and Amnesic Shellfish Poisoning: Revisiting Previous Paradigms". Phycologia. 51 (2): 168–216. doi:10.2216/11-37.1.
  10. ^ Trainer, V. L.; Bates, S. S.; Lundholm, N.; Thessen, A. E.; Cochlan, W. P.; Adams, N. G.; Trick, C. G. (2012). "Pseudo-nitzschia Physiological Ecology, Phylogeny, Toxicity, Monitoring and Impacts on Ecosystem Health". Harmful Algae. 14: 271–300. doi:10.1016/j.hal.2011.10.025.
  11. ^ Ramsdell, J. S. (2007). "The Molecular and Integrative Basis to Domoic Acid Toxicity". In Botana, L. (ed.). Phycotoxins: Chemistry and Biochemistry. Cambridge, MA: Wiley-Blackwell. pp. 223–250. doi:10.1002/9780470277874.ch13. ISBN 0-8138-2700-0.
  12. ^ Pulido, O. M. (2008). "Domoic Acid Toxicologic Pathology: A Review" (pdf). Marine Drugs. 6 (2): 180–219. doi:10.3390/md20080010. PMC 2525487. PMID 18728725.
  13. ^ Bates, S. S.; et al. (1989). "Pennate diatom Nitzschia pungens as the primary source of domoic acid, a toxin in shellfish from eastern Prince Edward Island, Canada". Canadian Journal of Fisheries and Aquatic Sciences. 46 (7): 1203–1215. doi:10.1139/f89-156.
  14. ^ Todd, E. C. D. (1993). "Domoic Acid and Amnesic Shellfish Poisoning: A Review". Journal of Food Protection. 56 (1): 69–83.
  15. ^ Quilliam M. A.; Wright J. L. C. (1989). "The Amnesic Shellfish Poisoning Mystery". Analytical Chemistry. 61 (18): 1053A–1060A. doi:10.1021/ac00193a002. PMID 2802153.
  16. ^ "Identification of Domoic Acid at National Research Council's Atlantic Lab" (pdf). Retrieved 9 May 2012.
  17. ^ Possibly drunk bird hits windshield Archived November 4, 2012, at the Wayback Machine
  18. ^ Domic Acid Information and History Archived May 13, 2009, at the Wayback Machine
  19. ^ Bargu, S.; Silver, M. W.; Ohman, M. D.; Benitez-Nelson, C. R.; Garrison, D. L. (2012). "Mystery behind Hitchcock's Birds". Nature Geoscience. 5 (1): 2–3. doi:10.1038/ngeo1360.

External links

Boquerones en vinagre

Boquerones en vinagre are a type of appetizer or tapa found in Spain. The central ingredient of the dish is the boquerones, fresh anchovies. The fillets are marinated in vinegar or a mixture of vinegar and olive oil, and seasoned with garlic and parsley. It is commonly served with beer or soft drinks, and rarely with wine.

Canadian Reference Materials

Canadian Reference Materials (CRM) are certified reference materials of high-quality and reliability produced by the National Metrology Institute of Canada – the National Research Council Canada. The NRC Certified Reference Materials program is operated by the Measurement Science and Standards portfolio and provides CRMs for environmental, biotoxin, food, nutritional supplement, and stable isotope analysis. The program was established in 1976 to produce CRMs for inorganic and organic marine environmental analysis and remains internationally recognized producer of CRMs.

Diarrhetic shellfish poisoning

Diarrhetic shellfish poisoning (DSP) is one of the four recognized symptom types of shellfish poisoning, the others being paralytic shellfish poisoning, neurotoxic shellfish poisoning and amnesic shellfish poisoning.

As the name suggests, this syndrome manifests itself as intense diarrhea and severe abdominal pains. Nausea and vomiting may sometimes occur too.

DSP and its symptoms usually set in within about half an hour of ingesting infected shellfish, and last for about one day. A recent case in France, though, with 20 people consuming oysters manifested itself after 36 hours. The causative poison is okadaic acid, which inhibits intestinal cellular de-phosphorylation. This causes the cells to become very permeable to water and causes profuse, intense diarrhea with a high risk of dehydration. As no life-threatening symptoms generally emerge from this, no fatalities from DSP have ever been recorded.

Domoic acid

Domoic acid (DA) is a kainic acid analog neurotoxin that causes amnesic shellfish poisoning (ASP). It is produced by algae and accumulates in shellfish, sardines, and anchovies. When sea lions, otters, cetaceans, humans, and other predators eat contaminated animals, poisoning may result. Exposure to this compound affects the brain, causing seizures, and possibly death.

List of Statutory Instruments of Scotland, 1999

This is an incomplete list of Scottish Statutory Instruments in 1999.

List of Statutory Instruments of Scotland, 2000

This is an incomplete list of Scottish Statutory Instruments in 2000.

List of Statutory Instruments of Scotland, 2001

This is an incomplete list of Scottish Statutory Instruments in 2001.

List of Statutory Instruments of Scotland, 2002

This is an incomplete list of Scottish Statutory Instruments in 2002.

List of Statutory Instruments of Scotland, 2003

This is an incomplete list of Scottish Statutory Instruments in 2003.

List of Statutory Instruments of Scotland, 2004

This is an incomplete list of Scottish Statutory Instruments in 2004.

List of Statutory Instruments of Scotland, 2005

This is an incomplete list of Scottish Statutory Instruments in 2005.

List of Statutory Instruments of Scotland, 2006

This is an incomplete list of Scottish Statutory Instruments in 2006.

Neurotoxic shellfish poisoning

Neurotoxic shellfish poisoning is caused by the consumption of shellfish contaminated by breve-toxins or brevetoxin analogs.Symptoms in humans include vomiting and nausea and a variety of neurological symptoms such as slurred speech. No fatalities have been reported but there are a number of cases which led to hospitalization.


Nitzschia is a common pennate marine diatom. In the scientific literature, this genus, named after Christian Ludwig Nitzsch, is sometimes termed Nitzchia, and it has many species described, which all have a similar morphology.

Paralytic shellfish poisoning

Paralytic shellfish poisoning (PSP) is one of the four recognized syndromes of shellfish poisoning, which share some common features and are primarily associated with bivalve mollusks (such as mussels, clams, oysters and scallops). These shellfish are filter feeders and accumulate neurotoxins, chiefly saxitoxin, produced by microscopic algae, such as dinoflagellates, diatoms, and cyanobacteria. Dinoflagellates of the genus Alexandrium are the most numerous and widespread saxitoxin producers and are responsible for PSP blooms in subarctic, temperate, and tropical locations. The majority of toxic blooms have been caused by the morphospecies Alexandrium catenella, Alexandrium tamarense, and Alexandrium fundyense, which together comprise the A. tamarense species complex. In Asia, PSP is mostly associated with the occurrence of the species Pyrodinium bahamense.Also some pufferfish, including chamaeleon puffer, contain saxitoxin, making their consumption hazardous.


Pseudo-nitzschia is a marine planktonic diatom genus containing some species capable of producing the neurotoxin domoic acid (DA), which is responsible for the neurological disorder known as amnesic shellfish poisoning (ASP). Currently, 52 species are known, 26 of which have been shown to produced DA. It was originally hypothesized that only dinoflagellates could produce harmful algal toxins, but a deadly bloom of Pseudo-nitzschia occurred in 1987 in the bays of Prince Edward Island, Canada, and led to an outbreak of ASP. Over 100 people were affected by this outbreak after consuming contaminated mussels; three people died. Blooms have since been characterized in coastal waters worldwide and have been linked to increasing marine nutrient concentrations.

Shellfish poisoning

Shellfish poisoning includes four (4) syndromes that share some common features and are primarily associated with bivalve molluscs (such as mussels, clams, oysters and scallops.) These shellfish are filter feeders and, therefore, accumulate toxins produced by microscopic algae, such as cyanobacteria, diatoms and dinoflagellates.


A toxin is a poisonous substance produced within living cells or organisms; synthetic toxicants created by artificial processes are thus excluded. The term was first used by organic chemist Ludwig Brieger (1849–1919), derived from the word toxic.Toxins can be small molecules, peptides, or proteins that are capable of causing disease on contact with or absorption by body tissues interacting with biological macromolecules such as enzymes or cellular receptors. Toxins vary greatly in their toxicity, ranging from usually minor (such as a bee sting) to almost immediately deadly (such as botulinum toxin).


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