Lake Erie Eutrophication

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Lake ErieEutrophication

• 1950s - 2000s

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Great Lakes

• Great Lakes basin is home to more than one-tenth
  of the population of the United States and
  one-quarter of the population of Canada.
• Some of the world's largest concentrations of
  industrial capacity are located in the Great
  Lakes region.

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Great Lakes

• Nearly 25 percent of the total Canadian
  agricultural production and 7 percent of the
  American production are located in the basin.
• Fourth seacoast In relation to US and Canadian
  industrial economies.

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Lake Erie

• 12th Largest lake in the world
• Detroit River from Lake Superior, Michigan, Huron
  and represents 95 of current inflow
• Outflow Niagara River to Lake Ontario
• Retention time (shortest) 2.6 years

64 m
7.4 m
29 m
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Lake Erie The Eutrophication Story

• Eutrophication (Eu truly , trophic
  nutritious) Rich in organisms and organic
  material.

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The Results

• 1950-60s -- Explosion of blue-green algae
  population
• 1970s -- much of central basin was anoxic and
  hypoxic due to decaying algae in late summer
  months
• "Dead Sea of North America
• Stress to commercial and sport fisheries
• Beach were closed

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The Source Problem-Phosphorus

• Sewage and Industrial Waste
• Introduction of phosphorus-based detergents post
  WWII.
• 9 million municipal population
• 2 million septic tanks population
• Agricultural Activity - Both Canada and US
• Drainage vast coastal wetlands
• Increased sediment runoff from tilled lands
• Increase phosphorus and nitrogen based fertilizer
  use

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The Solution

• International Joint Commission (IJC) determined
  that eutrophication was occurring as a result of
  the high phosphorus loading entering the lake in
  the 1950 and 1960s.
• 7.5 Billion spent since 1972 to bring into
  compliance with 1.0 mg/L phosphorus abatement
  program.
• Goal is 11,000 metric tons/year phosphorus
• Reduce the phosphorus in household detergents.

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Phosphorus Conceptual Model
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Stella Model
a Death Rate b Decomposition rate c
Utilization (uptake) rate
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Living Organic Phosphorus Stock (L)
input
output
     
L Living Stock I Inorganic Stock
a Death Rate b Decomposition rate c
Utilization (uptake) rate