This toxin is produced naturally by marinediatoms belonging to the genusPseudo-nitzschia and the speciesNitzschia 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 canbioaccumulate in many marine organisms that consumephytoplankton, such asanchovies andsardines. Intoxication by domoic acid in nonhuman organisms is frequently referred to asdomoic acid poisoning.
In the brain, domoic acid especially damages thehippocampus andamygdaloid nucleus.[1] It damages theneurons by activatingAMPA andkainate receptors, causing an influx ofcalcium. Although calcium flowing into cells is a normal event, the uncontrolled increase of calcium causes the cell to degenerate.[11][12]
ASP was first discovered in humans late in 1987, when a serious outbreak of food poisoning occurred in easternCanada.[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]
Epidemiologists fromHealth Canada quickly linked the illnesses to restaurant meals of cultured mussels harvested from one area inPrince Edward Island, a place never before affected by toxic algae. Mousebioassays on aqueous extracts of the suspect mussels caused death with some unusual neurotoxic symptoms very different from those ofparalytic shellfish poisoning toxins and other known toxins. On December 12, 1987, a team of scientists was assembled at theNational Research Council of Canada laboratory inHalifax,Nova Scotia. Integrating bioassay-directed fractionation with chemical analysis, the team identified the toxin on the afternoon of December 16, only four days after the start of the concerted investigation.[15][16]
According to the Channel Islands Marine and Wildlife Institute,
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.[18]
^abcClark, 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.PMID10485519. Archived from the original on 2011-08-11. Retrieved2008-08-13.
^Bates, S. S.; Trainer, V. L. (2006). "The Ecology of Harmful Diatoms". In Granéli, E.; Turner, J. (eds.).Ecology of Harmful Algae. Ecological Studies. Vol. 189. Heidelberg: Springer-Verlag. pp. 81–93.doi:10.1007/978-3-540-32210-8_7.ISBN978-3-540-74009-4.
^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.ISBN978-0-12-372584-4.
^Bargu, S.; Smith, E.; Ozhan, K. (2011). "Toxic DiatomPseudo-nitzschia and its Primary Consumers (Vectors)". In Seckbach, J.; Kociolek, P. (eds.).The Diatom World. Springer. pp. 493–512.ISBN978-9400713260.
^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.Bibcode:2012MMamS..28..237B.doi:10.1111/j.1748-7692.2011.00480.x.
^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.Bibcode:2012Phyco..51..168L.doi:10.2216/11-37.1.S2CID55094773.
^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.Bibcode:2012HAlga..14..271T.doi:10.1016/j.hal.2011.10.025.hdl:1912/5118.
^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.ISBN978-0-8138-2700-1.
^Bates, S. S.; et al. (1989). "Pennate diatomNitzschia 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.
^Bird, C. J.; Boyd, R. K.; Brewer, D.; Craft, C. A.; de Freitas, A. S. W.; Dyer, E. W.; Embree, D. J.; Falk, M.; Flack, M. G.; Foxall, R. A.; Gillis, C.; Greenwell, M.; Hardstaff, W. R.; Jamieson, W. D.; Laycock, M. V.; LeBlanc, P.; Lewis, N. I.; McCulloch, A. W.; McCully, G. K.; McInerney-Northcott, M.; McInnes, A. G.; McLachlan, J. L.; Odense, P.; O'Neil, D.; Pathak, V.; Quilliam, M. A.; Ragan, M. A.; Seto, P. F.; Sim, P. G.; Tappen, D.; Thibault, P.; Walter, J. A.; Wright, J. L. C.; Backman, A. M.; Taylor, A. M.; Dewar, D.; Gilgan, M.; Richard, D. J. A. (1988). Identification of domoic acid as the toxic agent responsible for the P.E.I. contaminated mussel incident: a summary of work conducted at the Atlantic Research Laboratory of the National Research Council, Halifax, between 13 Dec. 1987 and 11 Jan. 1988 (Report). National Research Council of Canada. Atlantic Research Laboratory.doi:10.4224/23000874.
