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1 RED TIDES By Stella Angeli Back ground taken from: http://biology.unm.edu/ccouncil/Biology_203/Images/Protists/dino1.gif

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. Picture taken from: www.whoi.edu/redtide/www.whoi.edu/redtide/

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) Background taken from: http://www.hkredtide.org/eng/images/Figure_1AlgalGrowthfactor.jpg

4 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 Background taken from: http://bp2.blogger.com/_QCWLAhyamfg/SDdrNx9eEpI/AAAAAAAAEc4/zj533-WqzLk/s1600-h/dead+fish.jpg Effects

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 Treatment in humans Filter masks(asthmatic symptoms) Intravenous fluids Antiemetics Asthma Medications : Albuterol, Dipheniramine, Cromolyn, Prednisone, Brevenal,bronchodilators

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. Background taken from: http://www.marine.usf.edu/microbiology/images/k-brevis-scan.jpg

7 Karenia brevis Classification Kingdom: Alveolata Phylum: Dinophyta Class: Dinophyceae Order: Gymnodiniales Background taken from: www.whoi.edu/redtide

8 Shared defining characters Picture taken from: http://dinos.anesc.u-tokyo.ac.jp/plankton/figure/Karenia_brevis.jpg Kingdom: Protista Flagella Chloroplasts Nucleus Single cells Phylum: Dinophyta Chloroplasts Spiraling swimming motion 2 flagella Nucleus Theca Grooves

9 Shared defining characters Picture taken from: http://dinos.anesc.u-tokyo.ac.jp/plankton/figure/Karenia_brevis.jpg Class: Dinophyta Apical plate Sulcus Thecal surface Chloroplasts Oval shape Ridges Order:Gymnodiale Order:Gymnodiales Sulcus located in the intermediate region of the cingulum Apical grooves Chloroplasts Fucoxanthin Cingulum Nucleus

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 Background taken from: http://www.liv.ac.uk/hab/Data%20sheets/k_brev/fig4.htm

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 Picture taken from: http://www.floridamarine.org/images/articles/17864/17864_3359.jpg

12 Karenia brevis detector “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) Picture taken from: http://coolgate.mote.org/socool/images/BreveBuster.jpg

13 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. 2005. 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. 1995. 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


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