Transcript Eutrophication 5.4

5.4 EUTROPHICATION
Connor
What is it?
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excessive richness of nutrients (especially
phosphates and nitrates) in a lake or other body of
water, frequently due to runoff from the land, which
causes a dense growth of plant life and death of
animal life from lack of oxygen.
Occurs in slow moving rivers and lakes primarily
Eutrophic means well nourished
When effects are undesirable it is considered a
form of pollution
The Processes of Eutrophication 5.4.1
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Fertilizer run-off and sewage
discharge flow into the body of
water
Run-off builds up at the bottom of
the body of water
Excess promotes plant growth
(primarily algae)
High level of organic matter and
decomposing organisms deplete
available oxygen in the water
Causes the death of other organisms
ie. fish
Over time the increased amount of
sediment can raise the bed of the
lake/river and allowing plants to
colonize the edges eventually turning
the area into dry land (in some
cases)
Impacts of Eutrophication
5.4.2
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Species diversity decreases and the dominant biota changes
The animal and plant life of a particular region, habitat, or
geological period
Plant and animal biomass increase
Turbidity increases
Turbidity is the amount of particulate matter that is suspended in
water
Rate of sedimentation increases, shortening the lifespan of the lake
Anoxic conditions may develop
Anoxic waters are areas of sea water, fresh water or groundwater
that are depleted of dissolved oxygen
Pollution Management Strategies
5.4.3
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Implement research and monitoring programs for
eutrophication
Raise awareness of eutrophication
Implement regulations to reduce nutrient losses
Create incentives to encourage nutrient reducing
actions ie. tax subsidies
Preserve and restore natural bodies of water that
are affected by eutrophication
Create institution to enforce policies and regulations
Example: Toxic Water in Toledo
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What happened? Sewage
from treatment plants and
fertilizer from farms were
discharged into the lake
causing an algae bloom
The bloom was close
enough to the city’s intake
valve that the water being
sent to the city was toxic
rendering it undrinkable
Regulations have been set
but officials have not
mandated any restrictions
as of yet.
Links
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Animated video
NatGeo Eutrophication Video
Eutrophication Song
BBC Bitesize Eutrophication
Sources
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BBC
USGS
Lenntech
WRI
NBC Toledo Water Crisis