Download presentation
Presentation is loading. Please wait.
Published byGladys Stafford Modified over 9 years ago
1
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
2
THE HARMFUL ALGAL BLOOM Red tides do not mean poison
3
Alexandrium cantenella Dinoflagellate microalgae Generally eastern Pacific Chain forming Dinoflagellate microalgae Generally eastern Pacific Chain forming WHERE DOES IT COME FROM?
4
Anchorage Fairbanks Juneau Ketchikan Sitka Kodiak Island Baranof Island Prince of Wales Island Kachemak Bay Seward ALASKA PSP OUTBREAK LOCATIONS PSP OUTBREAK LOCATIONS
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 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 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 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 Species High Toxicity Carbamate Toxins Moderate Toxicity Decarbamoyl Toxins Low Toxicity N-Sulfacarbamoyl Toxins Toxic algae GTX-III, STX B1, C2 Blue mussel GTX-III, GTXII, STX C1, C2, B1 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 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 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 CYST FORMATION Young Germling New Motile Cell Girdle Gametes Pellicle cyst Planozygote Gamete Fusion Sulcus Hypnocyst Vegetative Cell Division Theca plate Alexandrium Life Cycle
13
PLANKTON CYCLES IN THE MARINE WATERS OF ALASKA PLANKTON CYCLES IN THE MARINE WATERS OF ALASKA
14
OTHER NON-TOXIC ALGAE CAN CAUSE A RED TIDE
15
EFFECTS OF WIND AND CURRENTS TWO POSSIBILITIES EFFECTS OF WIND AND CURRENTS TWO POSSIBILITIES Wind River Current Freshwater plume Intense Red tide High toxicity
16
SYMPTOMS OF PSP FROM 143 CASES IN ALASKA FROM 1973-94 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
20
BUTTER CLAM/LITTENECK CLAM COMPARISON BLASHKE ISLANDS Date Butter clams Littleneck clams 13-Jan-0062472 14-Sep-0011234 03-Oct-0064533 11-Oct-0055433
21
LITTLENECK CLAM Seldovia Bay 8/19/97
22
BUTTER CLAM PSP Seldovia Bay 8/19/97 6/2/99 2/26/98 5/15/98 1/20/99
24
IS YOUR LIFE WORTH 11¢ Blue mussels can become toxic in half an hour. The FDA limit is 80 g
25
9/16/85 7/30/90 8/20/97 9/28/008/08/03 8/04/05 80 ug BLUE MUSSEL PSP Seldovia Bay
26
MOVEMENT OF THE TOXIN Algae Viscera and Gills Muscle Gonad
27
WHERE AND HOW MUCH? LocationDateAdductorVisceraGillsGonadsMantel AkhiokJune352,298221301340 Izhut Bay July584,9455041,361243 Swikshak Sept.<322,862-44641 Toxin Distribution in Weathervane Scallop
28
ALTERNATIVE TESTING? The Jellet Biotek Altert Kit TM 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
29
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 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
30
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 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
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.