Red Tide Gambierdiscus toxicus Vibrio vulnificus
Meridith Byrd
Gulf of Mexico Coastal Ocean Observing System
Recreational Boaters Workshop
May 28, 2009

Noctiluca sp. bloom, Southern California
Alexandrium sp. bloom
Penn Cove, Coupeville, WA www.serc.carleton.edu
Karenia brevis bloom, Charlotte Harbor, FL www.fiu.edu

Texas Red Tide: Karenia brevis
• Dinoflagellate
• single-celled algae
• plant and animal traits
• two flagella (locomotion)
• 15 μm in length (2000 per inch)
Tracy Villareal, UT Marine Science Institute
San Jose Island Oct 3, 2006 photo courtesy TDSHS

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• 8 major red tides since 1986
• 60 million fish killed
• 2006 most recent bloom
• Major blooms in late summer or fall
• start in the Gulf, currents transport bloom to shore
Once inshore can last days to months
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• Ship channels
Estuarine areas Port Mansfield, 1999
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• Manmade harbors
Subdivision canals
• Jetties

 San Jose Island
 Matagorda Island
 Cedar Bayou
 Mustang Island
 Padre Island
 Aransas Bay
 Redfish Bay
 Mesquite Bay
 Corpus Christi Bay
 22% gulf menhaden
 21% Atlantic bumper
 14% worm eel
 11% gulf whiting
 9% mullet
 8% pinfish / pigfish
 7% ladyfish
 5% Atlantic croaker
3% hardheads, red drum, snook, sand trout, jacks, snapper, others

Where does it come from?
Resident population in Gulf of Mexico.
What causes a bloom to end?
Low salinity (20 ppt)
Cold water (59 o F)
How often do blooms occur and why?
Florida: yearly
Texas: ~5 years Padre Island Oct 5, 2005

October 13, 2005
Corpus Christi Bay
Water discoloration easily seen from the air.

commons.wikimedia.org
TPWD photo www.nepa.gov
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Neurotoxin: damages or destroys nerve tissue enters through fishes’ gills attacks central nervous system: paralysis accumulates in fishes’ organs
• seabirds, dolphins, turtles accumulates on seagrasses
• green sea turtles, manatees

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Brevetoxin in shellfish concentrates in filter-feeding shellfish (oysters, mussels, clams, whelks)
• toxin levels can remain elevated for weeks to months
• toxin heat-stable, NOT destroyed by cooking
• Neurotoxic Shellfish Poisoning
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• lips, tongue go numb or tingle
GI symptoms dizziness reversal of hot and cold sensations
• Fish and crustaceans do not typically cause NSP

Texas Department of State Health Services
(TDSHS)
• Responsible for seafood safety.
• Criteria for bay closures:
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• Cell counts > 5000 cells per liter
Any detectable levels of toxin in shellfish
• Reopening bays can take weeks to months after red tide has dissipated
TDSHS photo
Maryland DNR photo

Brevetoxin: Human Health Effects
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Aerosols cause:
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• skin irritation coughing sneezing itchy, watery eyes runny nose wheezing, shortness of breath
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Symptoms depend on:
Cell concentration
Wind direction
Wind velocity
Wave action

Calm day: lessened symptoms
Rough surf: severe effects even with low cell numbers

www.tpwd.state.tx.us/hab/redtide

www.dshs.state.tx.us/seafood/default.shtm
“seafood”

To report a suspected red tide:
281-842-8100
512-389-4848
(TPWD 24 hr line)

Ciguatera Fish Poisoning: a New Concern in the
Northwestern Gulf of Mexico big thanks to Tracy Villareal, UTMSI and Andy Reich, FL Dept of Health

Ciguatera Fish Poisoning
• seafood toxicity that produces gastrointestinal, neurological, and cardiovascular symptoms
• can be fatal
• most cases are less severe although recovery may take weeks to years
• has no laboratory test - it is a diagnosis of exclusion
• over 400 species of tropical fish reported to be ciguatoxic
Halstead, 1967 slide courtesy Tracy Villareal, UT Marine Science Institute

Early European explorers reported sickness from eating fish
1511 Atlantic Ocean
1601 Indian Ocean
1606 Pacific Ocean after Halstead 1967
Typically associated with coral reefs on islands
Outbreaks are poorly understood
Multiple routes through food web to predators
(Kelly et al. 1992) slide courtesy Tracy Villareal, UT Marine Science Institute

Harmful Algal Bloom Food-borne Illnesses
Documented FATALITIES
Amnesic Shellfish Poisoning (ASP)
Paralytic Shellfish Poisoning (PSP)
Ciguatera
Venerupin Shellfish poisoning (VSP)
Clupeoid Fish Poisoning
REALLY UNPLEASANT (no known fatalities)
Diarrhetic Shellfish Poisoning (DSP)
Neurotoxic Shellfish Poisoning (NSP) slide courtesy Tracy Villareal, UT Marine Science Institute

Have you had ciguatera?
Fish eaten, followed by these symptoms within 72 hours
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Some of these: abdominal pain vomiting diarrhea nausea
AND http://www.cdc.gov/nceh/ciguatera/instructions.htm
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1 of these: slow heartbeat numbness, burning, or pricking around the mouth, sensation of temperature reversal slide courtesy Tracy Villareal, UT Marine Science Institute

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extremity numbness tingling, pricking, burning, or creeping on the skin pain in the joints, muscle pain malaise (not feeling right) itching headache dizziness metallic taste visual disturbances toothache, feeling of loose teeth slide courtesy Tracy Villareal, UT Marine Science Institute

Ciguatera: Poorly Understood
• 50,000 - 500,000 people affected annually around the globe (Fleming et al. 1998)
• significant under-reporting
• difficulties confirming cases and no laboratory test
• CDC estimates only 2%-10% cases reported in the US
• 32% of MDs in a ciguatera-endemic area
(Dade County, FL) could not diagnose it
• only 17% knew the correct treatment (McKee et al. 2000)
• 95% of the medical costs associated with algal toxins in the U.S. are due to ciguatera slide courtesy Tracy Villareal, UT Marine Science Institute

Case study: 1999
Amberjack served in a Chicago restaurant led to a cluster outbreak of 21 cases only 2 were diagnosed with ciguatera
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Diagnoses included allergies multiple sclerosis rheumatologic diseases dental abnormality
Specialists in urology, infectious disease, rheumatology and odontology had been consulted.
slide courtesy Tracy Villareal, UT Marine Science Institute

• Few documented cases, no public perception of a threat
• Fish migration behavior a factor
• toxin possibly acquired elsewhere, transported seasonally
• Significant human activity in the Gulf is altering habitat, particularly in the northern Gulf
• no oil production platforms before 1942
• now there are about 4000
• possibly the largest artificial reef complex in the world.
• Historically tied to island complexes, not continental shelves
• Gambierdiscus toxicus has been found on platforms along the continental shelf slide courtesy Tracy Villareal, UT Marine Science Institute

Rigs, Coral Reefs, Artificial Reefs
G. toxicus -
Present on platforms and
Sargassum fish migrations www.aslo.org
Coral reef Artificial Reef Oil rig
Villareal et a. 2007 slide courtesy Tracy Villareal, UT Marine Science Institute

2007: change in type of ciguatoxic fish and number of cases
• A highly publicized case in Galveston, TX created a local media frenzy
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• Other cases started to surface: TX-AL
Increased awareness slide courtesy Tracy Villareal, UT Marine Science Institute

Within 50 miles of Flower Gardens amberjack barracuda king mackerel yellow jack horse-eye jack
Within 10 nautical miles of Flower Gardens blackfin snapper dog snapper marbled grouper hogfish gag grouper scamp yellowfin grouper

Ciguatera Fish Advisory

Ciguatera Brochure slide courtesy Andy Reich, Florida Department of Health

The genus
V. cholerae
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• Naturally-occurring bacteria
~ 3 dozen species
Not all cause illness in humans
Oceans, brackish water worldwide
Warm temperatures
V. parahaemolyticus
V. vulnificus slide courtesy Kirk Wiles, Texas Department of State Health Services

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Occur naturally in warm coastal waters
• Levels highest April-October
Accumulates in tissues of filter-feeding shellfish
• oysters, clams
• does not affect appearance, taste, odor
• food poisoning if raw or undercooked
Can infect wounds
Serious consequences in at-risk people slide courtesy Kirk Wiles, Texas Department of State Health Services

Gastroenteritis (food poisoning)
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Occurs after consumption of contaminated food, particularly raw oysters
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Vomiting, diarrhea, cramps
Wound infection
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Occurs after a wound comes in contact with seawater containing V. vulnificus
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Swelling, redness, pain
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Often requires surgical debridement, amputation
Primary septicemia
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Occurs following either of above syndromes
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Fever, chills, skin lesions, drop in blood pressure, shock
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50% of cases are fatal slide courtesy Kirk Wiles, Texas Department of State Health Services

At-risk population includes those with:
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Liver disorders (hepatitis, alcoholism, cirrhosis)
• risk of death is 200 times greater than those without
Diabetes
Immunocompromising conditions
• HIV/AIDS
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• Cancer
Autoimmune disorder (lupus)
Hemochromatosis (metabolic iron disorder)
Gastric surgery or take antacids for ulcers slide courtesy Kirk Wiles, Texas Department of State Health Services

People without any risk factors
• May develop short duration gastroenteritis
1 – 3 days after eating affected shellfish
• May develop skin infection 1 – 3 days after having wound contact with saltwater
• Do not develop septicemia
• Have no long-term consequences
• Infections can be treated successfully with antibiotics, if detected early enough slide courtesy Kirk Wiles, Texas Department of State Health Services

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Should never eat untreated raw oysters
Could eat post-harvest treated oysters
• “Processed to reduce V. vulnificus to nondetectable levels”
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• high pressure high temperatures
• freezing temperatures
Should not go in salt water with an open wound
Are 80 times more likely to develop bloodstream infections than healthy people
(U.S. Centers for Disease Control)
The infectious dose for V. vulnificus is not known slide courtesy Kirk Wiles, Texas Department of State Health Services

slide courtesy Kirk Wiles, Texas Department of State Health Services

Examples of wound infections caused by Vibrio
vulnificus.
slide courtesy Kirk Wiles, Texas Department of State Health Services

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Do not contact seawater with open wound.
If you do, wash wound thoroughly with soap and water.
If wound becomes red or inflamed seek medical treatment.
• Do not delay seeking treatment.
slide courtesy Kirk Wiles, Texas Department of State Health Services

hi
Meridith

Vibrio infections in Texas

V. vulnificus Infections in Texas
• Average about 12 cases per year
• Summer consumption of Gulf coast raw oysters
• Some wound infection, septicemia cases
• 8:1 male/female ratio for V. vulnificus infections
• more males eating raw oysters, fishing?
• Average a few deaths per year
• Almost all from V. vulnificus
• Virtually all have one or more risk factors for V. vulnificus infection slide courtesy Kirk Wiles, Texas Department of State Health Services

V. vulnificus Infections in Texas
• Many cases likely not reported
• food poisoning, minor infections
• Case counting by TDSHS depends on:
• Ill person seeking medical attention
• Health care provider must:
• obtain specimen for culturing
• suspect Vibrio
• request specific test
• Laboratory detecting agent in specimen if present
• Laboratory or health care provider reporting to local or state health department
• Numbers of reported cases rise with public awareness slide courtesy Kirk Wiles, Texas Department of State Health Services

FOR MORE INFORMATION: www.safeoysters.org
Sea Grant
Texas Department of State
Health Services (TDSHS)
Kirk Wiles
512-834-6757

TPWD HAB website: www.tpwd.state.tx.us/hab
Meridith Byrd
361-575-6306 meridith.byrd@tpwd.state.tx.us