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THE HARMFUL ALGAL BLOOM

PARALYTIC SHELLFISH POISONING IN ALASKA By Raymond RaLonde University of Alaska Fairbanks School of Fisheries and Ocean Sciences Alaska Sea Grant Program Marine Advisory Program. THE HARMFUL ALGAL BLOOM. Red tides do not mean poison. Alexandrium cantenella. WHERE DOES IT COME FROM?.

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THE HARMFUL ALGAL BLOOM

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  1. PARALYTIC SHELLFISHPOISONING INALASKAByRaymond RaLondeUniversity of Alaska FairbanksSchool of Fisheries and Ocean SciencesAlaska Sea Grant ProgramMarine Advisory Program

  2. THE HARMFUL ALGAL BLOOM Red tides do not mean poison

  3. Alexandrium cantenella WHERE DOES IT COME FROM? • Dinoflagellate microalgae • Generally eastern Pacific • Chain forming

  4. PSP OUTBREAK LOCATIONS ALASKA Fairbanks Anchorage Kachemak Bay Juneau Ketchikan Sitka Seward Kodiak Island Baranof Island Prince of Wales Island

  5. ABOUT THE TOXIN Saxatoxin • The 24+ toxins are divided into three groups High Toxicity Carbamate Toxins Moderate Toxicity Decarbamoyl Toxins Low Toxicity N-Sulfacarbamoyl Toxins • Toxins change form and toxicity through the food chain Within the algae based on environmental conditions Within the shellfish based on their metabolism Within the final animal that eats the shellfish

  6. WHAT IS PSP? Biotoxin (24+ toxins) • Naturally occurring toxin • One of several marine toxins • Appear to be increasing in frequency • Range is expanding • Deadly toxin (~ 1,000 times that of strychnine) • Sodium channel blocking, blocking nervous transmission

  7. COMPLEX TOXICITY • Toxin Chemistry complex • Algae bloom process not understood • Oceanography complex and variable • Shellfish response differs by species

  8. THE TOXINS AND SHELLFISH Toxin types specified by high, moderate, low toxicity forms Shellfish High Toxicity Moderate Toxicity Low Toxicity Species Carbamate Toxins Decarbamoyl Toxins N-Sulfacarbamoyl Toxins Toxic algae GTX-III, STX B1, C2 Blue mussel GTX-III, GTXII, C1, C2, B1 STX Butter clam STX. GTX-II, GTXIII Littleneck clam dc-STX, dc-GTX-II, dc-GTX-III SXT - Saxitoxin GTX - Gonyautoxin dc-(STX,GTX) Decarbamoyl (Saxitoxin, Gonyautoxin) C(1,2) and B(1,2) - Sulfamate

  9. THE COMPLEX CHEMISTRY OF PSP

  10. MOUSE BIOASSAY THE ONLY APPROVED TEST

  11. TOXICITY WITHIN THE ALGAE • Algae strain (varying toxicity) • Environmental conditions • Temperature • Colder conditions cells are more toxic • Colder conditions less reproduction • Ocean nutrients • Low phosphorus cells are more toxic • High nitrogen more toxin produced • Iron suspected as a requirement for blooms

  12. Alexandrium Life Cycle Vegetative Cell Division Pellicle cyst Theca plate Girdle New Motile Cell Gametes Young Germling Planozygote Gamete Fusion Sulcus Hypnocyst Alexandrium CYST FORMATION

  13. PLANKTON CYCLES IN THE MARINE WATERS OF ALASKA

  14. OTHER NON-TOXIC ALGAE CAN CAUSE A RED TIDE

  15. Current Wind Wind Current River River Freshwaterplume Intense Red tide Freshwater plume Disbursed Red tide Low toxicity High toxicity EFFECTS OF WIND AND CURRENTS TWO POSSIBILITIES

  16. SYMPTOMS OF PSP FROM 143 CASES IN ALASKA FROM 1973-94

  17. WHEN DO PSP OUTBREAKS OCCUR? Outbreaks (1973-94)

  18. ALL COMMERCIALLY SOLD AND FARMED SHELLFISH HAVE BEEN CERTIFIED

  19. BUTTER CLAM/LITTENECK CLAMCOMPARISON

  20. LITTLENECK CLAMSeldovia Bay 8/19/97

  21. BUTTER CLAM PSPSeldovia Bay 8/19/97 2/26/98 5/15/98 1/20/99 6/2/99

  22. IS YOUR LIFE WORTH 11¢ Blue mussels can become toxic in half an hour. The FDA limit is 80 g

  23. BLUE MUSSEL PSPSeldovia Bay 8/20/97 7/30/90 8/04/05 9/16/85 9/28/00 8/08/03 80 ug

  24. MOVEMENT OF THE TOXIN Algae Viscera and Gills Muscle Gonad

  25. WHERE AND HOW MUCH? Toxin Distribution in Weathervane Scallop Location Date Adductor Viscera Gills Gonads Mantel Akhiok June 35 2,298 221 301 340 Izhut Bay July 58 4,945 504 1,361 243 Swikshak Sept. <32 2,862 - 446 41

  26. ALTERNATIVE TESTING?The Jellet Biotek Altert KitTM Pluses • Rapid (one hour) • Accurate when test is negative • No toxic chemicals • Easy to use • Inexpensive • processing kit for 40 samples $120 and $20/test Minuses • Representative sampling • May be too sensitive (measure toxins) • Not FDA approved yet • Don’t know how it will be accepted

  27. PREDOMINANT MYTHS • Only red tides are toxic • This beach has never been toxic • Lip test • Toxic months are only those where there is no “r” • Feed the cat • Cook the shellfish

  28. FOR MORE INFORMATION • Marine Advisory Program • http://www.uaf.edu/MAP/anch/raypubs.html • E-mail me at: afrlr@uaa.alaska.edu • Web Pages • http://www.redtide.whoi.edu/hab/ • http://www.bigelow.org/edhab/ • http://www.wsg.washington.edu/outreach/mas/aquaculture/algalfacts.html

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