Harmful Algal Blooms HABs by alicejenny


									               Harmful Algal Blooms
             Oceans and Human Health
                MBF 573 / EPH 584
   General characteristics: toxins, distributions
   Organisms: distributions, role of environment
   Response: clay (?)

"..and all the waters that were in the river were turned to blood.
And the fish that was in the river died and the Egyptians
could not drink of the water of the river and there was
blood through all the land of Egypt."        Exodus 7: 19-21
Toxic syndromes associated with marine algal toxins: (see Van Dolah, 2000)

Type           Genera           Vector           Toxin                Pharmacologic target

PSP1         Alexandrium sp.    Shellfish        Saxitoxins           Voltage-dependent
             Gymnodinium sp.                                          Na channel site 1
             Pyrodinium sp.

NSP2         Karenia sp.        Shellfish        Brevetoxins          Voltage-dependent
                                                                      Na channel site 5

ASP3         Pseudo-nitzschia   Shellfish        Domoic acid          Glutamate receptors

DSP4         Dinophysis          Shellfish       Pectenotoxins        Ser/Thr protein
             Prorocentrum                        Okadiac acid         phosphatases
                                                 Yessotoxins          (tumors)

CFG5         Gambierdiscus       Reef fish       Ciguatoxins          Voltage-dependent
                                                                      Na+ channel site 5

             Pfiesteria           Water          None/free radical    Direct fish consumption

         Shellfish Poisoning, 2Neurotoxic SP, 3Amnesic SP, 4Diarrhetic SP,
5Ciguatera Fish Poisoning
   Saxitoxin                  Brevetoxins
(PSP -guanidines)               (NSP)
                            Blocks Na+ channels

                      Ciguatoxin (CFP)
                      Opens Na channels

                    Okadaic acid (DSP)

                    Domoic acid (ASP)
How are Na channels affected ? (example: NSP)

          Images above from http://www.bigelow.org/hab/toxin.html

                                                          Brevetoxin PbTx-2

  Further information is at http://www.rsmas.miami.edu/groups/niehs/science/redtide.htm
An increased global incidence
of Harmful Algal Blooms
(HABs) between 1970 -1999:



1. Southward expansion

2. Increased occurrences
Coastal Problems in the United States:
         1972 to present


   DSP occurrence

   Enhanced PSP distribution

Nontoxic algal effects:

   Pfeisteria hysteria

   Anoxia (low oxygen)

   Macroalgal blooms
Possible Link to Eutrophication:

Hong Kong Harbor:
Relationship of HAB
occurrence and
population growth.
Concurrently N and P
increased 25- and

      Seto Inland Sea, Japan.
      Improved nutrient
      management in early 1970s
      reduced HAB occurrence
      as N, P declined

                             Pseudo-nitzschia sp. in cores
                                (potential for ASP)

Elevated nutrient inputs from
Mississippi River coincide with
elevated diatoms in coastal
Louisiana sediments
Economic Impacts:
• Public health
• Fisheries
• Recreation
• Management/Monitoring
Estimated Annual Economic Impact from HABs in the USA
  (data from 1987 – 1992 presented as year 2000 dollars)
                                        Pfiesteria piscicida:
                                        Nontoxic, non-
                                        photosynthetic peridinioid

                                        US: Middle east coat estuaries

                      Hypotheca         Kills fish by consumption
                                          (first report 1988 in Tilapia
                                               aquaculture - NCSU)

Cell diameter ≈ 20µ

See Text Chapter 16: Vogelbein et al.
   Proposed 24 life cycle stages; in reality, life cycle is much simpler

Red = toxic; yellow = ?, blue = nontoxic
Ciguatera Fish Poisoning: Subtropical waters, Caribbean, Pacific
                 Chapter 14: Bienfang et al

                                                                               Cell diameter
                                                                               80 – 90 µm

 Gambierdiscus australes http://www.nmnh.si.edu/highlight/sem/highlight/dinos/21.htm)
 Gambier Islands (French Polynesia): food webs & biomagnification
CFP: „cigua‟ (Spanish Antilles, turban snail)

    • Settles on macroalgae in reef environments.
    • Precursors to ciguatoxins consumed by grazing fish.
    • Effect biomagnified up the food chain.
CFP Symptoms analogous to type E botulism, scombroid poison,
                           org-PO4 poisoning

A. Symptoms:
1. Gastrointestinal: vomiting, abdominal pain, nausea, diarrhea
    few days (Caribbean)

2. Neurological: numbness/tingling, dizziness, hot/cold perception
   weeks, months, years (Pacific)

B. Characteristics:

CTX is toxic to adult humans at pg quantities and fish cannot be “purified” of CTX

Death rare: occurs by respiratory shock when fish live, viscera are eaten

Treatment: mannitol infusion @ 0.5 – 1.0 g/kg body weight (opens swelling at nodes)

Reports of ≈ 50,000 cases/annum but likely under-reported 10-fold
Detritivores on reefs and carnivores: can retain CTX for > 30 months.
  (parrotfish, jacks, barracudas, groupers, snappers, moray eels, surgeonfish)
                        West Coast HABs (PSP, ASP):

Alexandrium catenella (Whedon & Kofoid) (Paralytic SP)

                        Pseudo-nitzschia sp. (Amnesic SP)
PSP: Saxitoxin (STX from Saxidomus giganteus, Alaskan butter clam)


  In both cyanobacteria (Lyngbya) and dinoflagellates, 28 analogues
  Water soluble (fats uptake across GI tract)
  Acts to block voltage sensitive Na Channels –same site as terodotoxin
  Symptoms: tingling mouth, digits; GI tract (usual suspects) and paralysis
  Several cases from Indian River Lagoon, FL due to toxic puffer fish
                       Pyrodinium bahamense
Pseudo-nitzschia sp.
  Identified in 1987 as source of ASP from maritime Canada
  Domoic Acid heat-stable, water soluble
  Competes with glutamate for binding site in neurons

See Chapter 12: Trainer et al.

Siliceous frustule
NW Native Americans reliance on shellfish:

Creation myths: escape from shellfish

Food: dried horse clam

Ceremonial rites
Canadian First Nations Heiltsuk: 50% of
all commercial harvests are by First
Nations people.

ORHAB Program: Quileute
• rapid screening for PSP
• domoic acid dipstick
• NWFSC & Jellett Biotek

 California tribes
 prohibited shellfish
 harvesting when
Alexandrium fundyense,
Paralytic Shellfish Poisoning (PSP) in
eastern US coastal waters

   Cysts (overwinter)

                                         Vegetative (spring, summer)
Spring-Summer 2005 HAB event in New England coastal waters
                       clams, quahogs, mussels, scallops,
                           oysters mainly in summer

Timing of runoff and
                                                        Strong winds can
weak winds influence
                                                        terminate blooms
bloom initiation
                                                        in the fall.
Alexandrium in the Gulf of Maine


                         Karenia brevis: Florida red tide organism

Brevetoxin PbTx: 12 congeners
 brevanol – Dan Baden lecture
        Life cycle of Karenia brevis

                  Diel cycles occur of vertical migration.

                  Seasonality and cross-shelf distributions1.


Offshore initiation

 1Walsh,  et al., 2002. A numerical analysis of landfall of the 1979 red
 tide of Karenia brevis along the west coast of Florida.
       FMRI Weekly bulletin: microscopic cell counts
       (2005 Spring-summer K. brevis outbreak on FL west coast)

Mote Beach Conditions Report: Residents and visitors without Internet access
may also access the report by calling 941-BEACHES (941-388-5223).

Reports issued at 10 a.m. and 3 p.m. daily.
The information is date and time stamped so
the public knows how recent a report is.
           NOAA HAB Bulletins: monitoring and prediction

Target Study Area
                                          2005 Florida West
                                           coast Karenia bloom

                                          Feb 11 HAB Bulletin

Brevebuster: automated optical
 detection system (absorbance of
 pigment spectra in situ).

Gary Kirkpatrick, Mote Marine Lab
Autonomous Underwater Vehicle
 (AUVs) equipped with brevebuster

Oscillates in water column
Slocum glider
  Webb Research Woods Hole MA
Deployments days -weeks
A frequent question is ”Can HABs be controlled”?


        Korean aquaculture:            HAB
        Clay treatments reduced
        fish losses in pens
        from $100M to $1M

Mote Marine Lab and WHOI
are evaluating clay flocculation
to reduce K. brevis cell
concentrations in Sarasota Bay.

Wind, turbulence may
determine if deleterious
effects occur in benthos

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