Causative Organism: Karena spp.

Morphology/taxonomy: (7*, 22)

Approximate Size: 18–32 um in length, 18–48 um in width, and 10–15 um in thickness (7)

Mode of Activity: Binds with high affinity to site 5 of the voltage-dependent sodium channel α-subunit (2, 8)

Toxicity: MUs: 4.0 μg brevetoxin-2 (19*, 21)

Geographic range: 10o N - 40o N.  Blooms of K. brevis are predominant in the Gulf of Mexico and Caribbean Sea, but brevetoxin outbreaks have been recorded in North Carolina and Delaware (19*, 20)

Species:

Karena brevis is the prominent species known to produce brevetoxin. (7, 19)*

Impacts of Toxin

Marine Food Web:

Blooms of K. breves has been attributed to massive fish kills (13, 17,19*), death of waterfowl (12), and marine mammals (15, 16, 19*)

Economic:

Closing of clam beds to harvesting have occurred during brevetoxin outbreaks, but current guidelines do not limit the consumption of fillets from healthy finfish harvested during or after a red tide bloom (18, 19*)
The tourism industry suffers considerable economic loss during K. brevis blooms(23*, 25)

Human Health

Name of Malody: neurotoxic shellfish poisoning (NSP) (23)

Symptoms:
Consumption: Symptoms usually resolve in 2-3 days after ingestion and include tingling of the mouth and extremities (paraesthesia), dizziness, muscle paralysis, nausea, vomiting, diarrhoea, chills, motor incoordination, double vision, hot-cold flashes, low blood pressure (hypotension), cramps, abnormal heart rhythm (arrhytmias), double vision, bronchoconstriction, and paralysis. (5, 6*)
Inhalation: Upper and lower respiratory irritation, burning of eyes, nose, and throat, and can induce asthma attacks in susceptible individuals. (3, 4)*

Incidents: (18*)

*and references cited therein.  **MU (mouse unit): the amount of crude toxin that will kill a 20-gm in 15 minutes, or the LD50 of the population in 24 hours

References

1. K. A Steidinger et al., “Bloom dynamics and physiology of Gymnodinium breve with emphasis on the Gulf of Mexico,” Physiological ecology of harmful algal blooms (1998): 135–153. 
2. F. M Van Dolah, “Diversity of marine and freshwater algal toxins,” in Seafood and freshwater toxins: pharmacology, physiology, and detection. L. M Botana, Ed. (New York: CRC, 2008): 19–43. 
3. L. C Backer et al., “Recreational exposure to aerosolized brevetoxins during Florida red tide events,” Harmful Algae 2, no. 1 (2003): 19–28. 
4. Y. S Cheng et al., “Characterization of red tide aerosol on the Texas coast,” Harmful Algae 4, no. 1 (2005): 87–94. 
5. L. C Backer et al., “Marine phycotoxins in seafood,” Toxins in food (2005): 155–189. 
6. N. Vilarino et al., “Use of Biosensors as Alternatives to Current Regulatory Methods for Marine Biotoxins,” Sensors 9 (2009): 35-40. 
7. Allison J. Haywood et al., “Comparative Morphology and Molecular Phylpgenetic Analysis of Three New Species of the Genus Karenia (Dinophyceae) from New Zealand,” Journal of Phycology 40, no. 1 (2004): 165-179. 
8. Robert E. Gawley et al., “The relationship of brevetoxin `length' and A-ring functionality to binding and activity in neuronal sodium channels,” Chemistry & Biology 2, no. 8 (August 1995): 533-541. 
9. Yuzuru Shimizu et al., “Structure of brevetoxin A (GB-1 toxin), the most potent toxin in the Florida red tide organism Gymnodinium breve (Ptychodiscus brevis),” Journal of the American Chemical Society 108, no. 3 (1986): 514-515. 
10. K. C. Nicolaou et al., “Total Synthesis of Brevetoxin B. 3. Final Strategy and Completion,” Journal of the American Chemical Society 117, no. 41 (1995): 10252-10263. 
11. Yong-Yeng Lin et al., “Isolation and structure of brevetoxin B from the "red tide" dinoflagellate Ptychodiscus brevis (Gymnodinium breve),” Journal of the American Chemical Society 103, no. 22 (1981): 6773-6775. 
12. D. J Forrester et al., “An epizootic of waterfowl associated with a red tide episode in Florida,” Journal of Wildlife Diseases 13, no. 2 (1977): 160. 
13. Gordon Gunter et al., “Catastrophic Mass Mortality of Marine Animals and Coincident Phytoplankton Bloom on the West Coast of Florida, November 1946 to August 1947,” Ecological Monographs 18, no. 3 (1948): 309-324. 
14. S. L Purkerson-Parker et al., “Brevetoxin derivatives that inhibit toxin activity,” Chemistry & Biology 7, no. 6 (2000): 385–393. 
15. G. D Bossart et al., “Brevetoxicosis in manatees (Trichechus manatus latirostris) from the 1996 epizootic: gross, histologic, and immunohistochemical features,” Toxicologic Pathology 26, no. 2 (1998): 276-282. 
16. V. L Trainer and D. G Baden, “High affinity binding of red tide neurotoxins to marine mammal brain,” Aquatic Toxicology 46, no. 2 (1999): 139–148. 
17. C. Kreuder et al., “Clinicopathologic features of suspected brevetoxicosis in double-crested cormorants (Phalacrocorax auritus) along the Florida Gulf Coast,” Journal of Zoo and Wildlife Medicine 33, no. 1 (2002): 8–15. 
18. A. J Bourdelais et al., “New fish-killing alga in coastal Delaware produces neurotoxins.,” Environmental health perspectives 110, no. 5 (2002): 465. 
19. K. A. Steidinger et al., “Neurotoxic shellfish poisoning due to toxin retention in the clam Chione cancellata,” Harmful Algae (1998): 457–458. 
20. K. A Steidinger and D. G Baden, Toxic marine dinoflagellates, IN Spector, D.L. (Orlando, Fl: Academic Press, 1984). 
21. B. D Gessner, “Impact of toxic episodes: neurotoxic toxins,” Seafood and freshwater toxins: pharmacology, physiology, and detection (2000): 65-90. 
22. http://www.marinespecies.org/aphia.php?p=taxdetails&id=233015
23. Bienfang, P.K. et al., 2011. Prominent Human Health Impacts from Several Marine Microbes: History, Ecology, and Public Health Implications. International Journal of Microbiology, 2011.
24. Fleming, L.E., Backer, L.C. & Baden, D.G., 2005. Overview of aerosolized Florida red tide toxins: exposures and effects. Environmental health perspectives, 113(5), 618.
25. Alcock, F., 2007. An assessment of Florida red tide: Causes, consequences and management strategies, Technical Report.