1. RED TIDES By Stella Angeli
Back ground taken from:

2. What is red tides?
Red tide is a common name for a phenomenon known as algal bloom, that occurs when toxic, microscopic algae in sea water proliferate to higher than normal concentration often discoloring the water red, brown, green or yellow.
World distribution: Mexico, Texas, Florida, South and North Carolina and others.
Most blooms last three to five months and may affect hundreds of square miles.
As the bloom increases the density of red tide organisms increase to several million cells in each liter of sea water, creating visible patches near the water’s surface.
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3. Causes of red tides
The causes of red tides are unclear but experienced scientists have arrived at the conclusion that some specific factors might have caused the phenomenon:
Result of human activities
Coastal upwelling, a natural result of the movement of certain ocean currents
Coastal water pollution
Systematic increase in sea water temperature
Iron-rich dust influx from large desert areas such as the Saharan desert
El Niño events (ocean-atmosphere phenomenon)
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4. Effects
Kills fish, invertebrates such as certain clams and oysters, other marine mammals such as dolphins, and water fowl and other birds.
On humans health problems
Tingling in lips, tongue and throat
Diarrhea, vomiting
Asthmatic symptoms
Temperature ́reversals΄: cold feels hot and vice versa
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5. Elimination and treatment in humans
Researchers at Florida International University in Miami are experimenting with using 640-kilohertz ultrasound waves that create micropressure zones as hot as 3,700 °C. This breaks some water molecules into reactive fragments that can kill algae.
Treatment in humans
Filter masks(asthmatic symptoms)
Antiemetics
Asthma Medications : Albuterol, Dipheniramine, Cromolyn, Prednisone, Brevenal,bronchodilators
Intravenous fluids

6. Which organism causes the red tides?
The organism that causes the red tides is a microscopic alga called Karenia brevis, which produces strong chemical brevetoxins that can harm manatees and many other species of aquatic life.
Initiation and Transport
The initiation of Karenia brevis happens in four stages:
Karenia brevis population is first introduced into an area
Growth, during which the population steadily increases
Maintenance, during which the bloom may be maintained in a circulation feature offshore or moved inshore by wind and currents
Dissipation/termination. Mechanisms that contribute to this stage, such as winds and currents, may disperse the cells, introduce new water masses, or move the bloom to a different area.
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7. Karenia brevis Classification Kingdom: Alveolata Phylum: Dinophyta
Class: Dinophyceae
Order: Gymnodiniales
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8. Shared defining characters
Flagella
Kingdom: Protista
Chloroplasts
Nucleus
Single cells
Chloroplasts
Spiraling swimming motion
Phylum: Dinophyta
2 flagella
Nucleus
Theca
Grooves
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9. Shared defining characters
Apical plate
Sulcus
Class: Dinophyta
Thecal surface
Chloroplasts
Oval shape
Ridges
Sulcus located in the intermediate region of the cingulum
Order:Gymnodiales
Apical grooves
Chloroplasts
Fucoxanthin
Cingulum
Nucleus
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10. Features Karenia brevis is a photosynthetic dinoflagellate.
Cells are squarish in outline and are strongly dorso-ventrally flattened. The girdle is not or only slightly displaced.
Length: 23-24µm
Width: 24-36µm
Depth: 10 to 15 µm
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11. Features (2)
Apical groove- at the anterior part of the cell extending on both the ventral and dorsal sides.
Chloroplast-contains chlorophyll
Cingulum (girdle) -A furrow encircling the cell
Cingular ridges-Longitudinal ridges in the cingulum
Fucoxanthin-A brownish accessory pigment used in capturing energy.
Longitudinal and transverse flagellum-like a rudder, steers the cell-when beating propels the cell.
Nucleus
Sulcus-The longitudinal area on the ventral surface of the cell
Theca (also called cell covering or cell wall)- Multiple membrane layers contains vesicles, bladderlike cavities
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12. Karenia brevis detector
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“Breve Busters optically detect Karenia brevis blooms by comparing light absorption by particles in ambient water to the light absorption fingerprint that is characteristic of K. brevis. That comparison yields a Similarity Index (SI) which is related to the fraction of phytoplankton community biomass contributed by K. brevis. Values of SI below 0.5 indicate less than 10% K. brevis, values over 0.8 indicate greater than 90% K. brevis.” (Sarasota Operations Coastal Ocean Observation Lab)

13. Background is taken from: Dr
Background is taken from: Dr. Barbara’s Kirkpatrick lecture( START Board Member)

14. Programs associated with red tides
- Study what causes HABs and how they can be predicted and prevented
NOS Programs
NOAA Marine Biotoxins Program
IOC Harmful Algal Bloom Programme
ECOHAB program- Florida etc.

15. References
Article from: Environmental health ,Harmful algal bloom, 2008
Article from: Fish and Wildlife Research Institute, Red Tides in Florida
Article from: Laurin Publishing, 'FlowCytobot' Detects Blooms, 2008
Article from: Roth P The microbial community associated with the Florida red tide dinoflagellate Karenia brevis: algicidal and antagonistic interactions. MS thesis. The College of Charleston, Charleston, South Carolina.
Article from: Anderson, D.M ECOHAB: the ecology and oceanography of harmful algal blooms: A national research agenda. Woods Hole Oceanographic Institute.
Article from: Hansen et Moestrup, 1989,Karenia brevis (Davis)
Article from: Earth Observatory,NASA Satellites Detect “Glow” of Plankton in Black Waters,2004
Article from: National Ocean Service, Harmful Algal Blooms,2007
Article from: Ocean World ,Red Tides,2004
Article from : Shifting Baselines Blog, Can Red Tide Make You Sick?,2005
Article from: National Centers for Coastal Ocean Science, Silver Spring,2008, MD., USA
Article from: Journey North, What is red tide?, 2003