The Effect of Temperature on Algal Blooms

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The Effect of Temperatureon Algal Blooms

• Dr. Scott Sowell
• Senior Seminar
• April 23, 2013

2
Introduction

• Algal blooms are potentially dangerous events
  that can have negative environmental consequences
• Happen more and more often
• Can cause fish kills, human respiratory problems,
  and reduce water quality
• Living near the St. Johns
  River, those of us in Jacksonville have an
  ethical responsibility to be aware of this
  problem.

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Relevant Literature

• Inorganic nutrients (N, P, and K) are limiting
  factors for plant growth (Albert, 1998 Smith,
  2012 Thomas, 2009)
• Anthropogenic sources (e.g., agricultural runoff
  or municipal wastewater) unnaturally increase
  these nutrients (Johnson, 2002, Klein, 2004)
• Plant populations increase (algal bloom) then die
  off, resulting in high rates of decomposition
  and dangerous hypoxic conditions (Newton, 2000
  Marlow, 1999 Zeiler, 2000).

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Relevant Literature

• Cultural eutrophication of our local waterways
  can have both immediate and long-lasting effects
  (Dalonega, 2001 Ellington, 2002 Frazier, 2000)
• Temperature and other abiotic factors have been
  known to slow down algal bloom (Conrad, 2000
  Dutton, 2005 Hodges, 1999).
• Temperature is one such abiotic factor that can
  affect algal blooms (Keys, 1999 Salmon, 2007)
• Certain species of algae have different ranges of
  tolerance for temperature (Dalonega, 2001 Evans,
  2008)

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Methods

• Grew 20 cultures of three different species of
  cyanobacteria (green algae) in separate
  containers
• Each container was maintained at a certain
  temperature (2 at each of ten temperatures 20?C
  20, 22, 26, 28, 30, 32, 34, 36, 38, 40
• Microscopic counts were taken of each culture
  every day for 30 days

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Algae Cultures Counts
Counting Algae on Microscope
Algae Culture Bottles
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Results
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Results

• The majority of algal cells demonstrated a range
  of tolerance of 24-32 ?C
• All temperatures below 24?C or above 32?C
  resulted in minimal or no algae growth
• This was true for all species except for C.
  laticeps that had a higher range of tolerance
  into the upper temperatures

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Discussion

• To mitigate the effects of an algal bloom,
  temperatures should be regulated below 24 ?C or
  above 23 ?C
• This would not be true for C. laticeps that
  demonstrated an extended range of tolerance into
  the upper temperatures
• This also points to warnings that springtime
  local temperatures are most conducive to algal
  blooms