Microcystis Blooms

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Microcystis Blooms

• Causes, Problems, and Solutions
• By Bernie Coates

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What is it?

• Microcystis is a blue-green algae (cyanobacteria)
  commonly found in nutrient rich freshwater. Its
  blooms are being found more frequently and its
  associated toxins are cause for worldwide concern.

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Causes

• Microcystis blooms are usually caused by
  eutrophication (nutrient enrichment) of the water
  body. Typically the limiting nutrient is
  phosphorous. Blooms can be encouraged by
• Fertilizer runoff from fields, golf courses, and
  urban lawns
• Untreated, or partially-treated, domestic sewage
• Liberation of phosphorous from the lake or pond
  bottom under reducing conditions
• The presence of Microcystis can actually increase
  the liberation of phosphorous from the sediments
  thereby accelerating bloom growth (Xie, Xie,
  Tang, 2000).

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Some Microcystis Blooms
Photo from Experimental Lakes Area in Manitoba,
Canada
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Unknown Pond
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Lake Mokoan, Victoria, Australia
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Balgavies Loch, Dundee, Scotland, 1981
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Grandview Garden Park, Beijing
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Problems

• Microcystis contain toxins known as microcystins.
  These toxins can cause fish kills and in some
  instances have resulted in human casualties.
• There are several other cyanobacteria species
  that produce microcystins including
• Anabaena
• Oscillatoria
• Nostoc
• Hapalosiphon
• Anabaenopsis

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• Microcystins are hepatotoxins.
• Acute toxicity is the main concern with
  Microcystins. The compound attacks the liver
  causing hemorrhaging and liver failure.
• The threat to human health is of great concern
  since long-term exposure to relatively low doses
  could encourage the development of liver tumors.

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Occurrences

• In February 1996 sixty patients with kidney
  failure died and 66 others were rendered ill in a
  hemodialysis clinic in Caruaru, Brazil, when
  untreated turbid water contaminated with
  Microcystis was used for dialysis during a water
  shortage.

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Occurrences

• A large epidemic in Brazil involving human
  deaths occurred in 1988. Over 2,000 residents
  suffered from gastroenteritis over an 8-week
  period, with 88 deaths. An epidemiologic
  investigation implicated drinking water from a
  reservoir, even water that had been boiled before
  use. Infectious agents, metals or toxins were not
  found however, the cyanobacterium genera
  Anabaena and Microcystis were found in great
  quantities in untreated water from the reservoir.
  Algal toxins were not assayed, but the
  circumstantial evidence strongly implicated the
  cyanobacteria as the cause.

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Chemical Solutions

• Limit influx of nutrients to the water by more
  efficient fertilizer application techniques.
• Dredging lakes and ponds where there are high
  amounts of phosphorous tied up in the sediments.
• Application of aluminum sulphate and copper
  sulfate in combination (Hullebusch, Delutat,
  Chazal, Baudu, 2002) .

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Non-chemical Solutions

• Non-chemical means of control was achieved using
  barley straw extract made from decomposed barley
  straw. Experiments produced a 10-fold decrease in
  Chlorophyll a levels (Ball, Williams, Vincent,
  and Robinson, 2001) .
• Ultraviolet (UV) radiation in small doses prior
  to bloom development inhibits reproduction.
  Additionally, UV increases the specific gravity
  of the cells thereby limiting their ability to
  remain in suspension, which effectively stops the
  Microcystis from photosynthesizing (Alam, Otaki,
  Furumai, Ohgaki, 2001).

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Other Solutions

• Bank filtration
• Ozonation
• Reverse osmosis
• Activated carbon treatment

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Acknowledgements
Xie, L.Q., Xie, P., Tang, H. Enhancement of
dissolved phosphorous release from sediment to
lake water by Microcystis bloomsan enclosure
experiment in a hyper-eutrophic, subtropical
Chinese lake. Environmental Pollution.
200312391-399. Hullebusch, E., Deluchat, V.,
Chazal, P., Baudu, M. Environmental impact of
two successive chemical treatments in a small
shallow eutrophied lake Part I II. Case of
aluminum sulphate. Environmental Pollution.
2002120617-634.
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Acknowledgements
Ball, A., Williams, M., Vincent, D., Robinson,
J. Algal growth control by a barley straw
extract. Biosource Technology.
200177177-181. Alam, M., Otaki, M., Furumai,
H., Ohgaki, S. Direct and indirect inactivation
of Microcystis aeruginosa by uv-radiation. Wat.
Res. No. 4. 2001351008-1014.
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And NowFor Something Completely Different
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Yukio Yamada

• A Leader in Phycology in Japan Considered to be
  the founder of modern Japanese phycology

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Yamadas Background

• Born in 1900 in Kyoto Japan
• Entered Daiichi High School in 1918
• In 1921, Yamada entered the Botanical Institute
  of the Faculty of Science at the Imperial
  University of Tokyo
• Professor Bunzo Hayata convinced Yamada he should
  study algae

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Positions Held

• Professor of Taxonomic Botany for the Faculty of
  Science at Hokkaido University in Sapporo
• First director of the Institute of Algological
  Research
• Member of the University Senate and Dean of the
  Faculty of Science at Hokkaido University
• Founded and served as president of the Japanese
  Society of Phycology
• President of the International Phycological
  Society

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Primary Contributions

• Detailed taxonomic, morphological and floristic
  accounts of red, brown and green algae from Japan
• Described nearly 200 new taxa of marine algae
• Floristic Studies of marine algae from Taiwan
• Life history studies of various marine algae,
  especially Chlorophyta
• Mentor for almost 50 graduate students

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Acknowledgement

• Garbary, David J., and Michael J. Wynne, eds.
• Prominent Phycologists of the 20th Century.
• Hantsport, Nova Scotia Lancelot Press
  Ltd.,1996.