Eutrophication is a process where bodies of water become over-enriched with minerals and nutrients which induces excessive growth of algae. This disrupts water quality and the balance of aquatic life. Humans exacerbate eutrophication through activities like sewage discharge, agricultural runoff, and atmospheric deposition which introduce fertilizers and other nutrients into bodies of water. Eutrophication follows stages including growth of plants due to nutrient addition, then algal blooms, followed by lack of oxygen as decomposers use up oxygen and plants die off.

1. …..EUTROPHICATION
By-HIMANSHU JAIN
JUNIOR

2. When lakes, streams
and estuaries are over
fertilized, excessive
production of aquatic
organic matter can
become a water
quality
problem and as a
result the
eutrophication
process can be
enhanced!
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3. However, humans in their everyday activities
can exacerbate the process:
Point sources (can locate the cause)
 Sewage treatment plant discharges
 Storm sewer discharges
 Industrial discharges
Non-point sources (can’t locate the cause,
it’s everywhere)
 Atmospheric deposition
 Agricultural runoff (fertilizer, soil erosion)
 Septic systems
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4. Eutrophication: a process
by which a body of
water progresses from its
origin to its
extinction. This process
happens in stages.
BEFORE EUTROPHICATION
AFTER EUTROPHICATION
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5. LACK OF OXYGEN
GROWTH OF BACTERIA
DEATH OF PLANTS
SUFFOCATION
GROWTH OF PLANTS
ADDITION OF NITRATES
Eutrophication process in 6 stages
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6. fe rtilis e rs
s e w a g e
(liq u id d o m e s tic
a n d in d u s tria l w a s te )
m in e ra ls
e s p . n itra te s
m in e ra ls
e s p . p h o s p h a te s
e u tro p h ic a tio n
a lg a l b lo o m
c o m p e titio n
fo r lig h t
c o n s u m e rs c a n ' t
c o n s u m e fa s t e n o u g h
d e a d p la n ts d e a d a lg a e
Theprocessof
Eutrophication
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7. c o m p e titio n
fo r lig h t
c o n s u m e rs c a n ' t
c o n s u m e fa s t e n o u g h
d e a d p la n ts d e a d a lg a e
d e tritu s
m o re d e c o m p o s e rs
u s e u p o x y g e n
b y a e ro b ic re s p ira tio n
rial
The process of Eutrophication cont.
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8. Biochemical Oxygen Demand (BOD).
This measures the rate of oxygen consumption by a
sample of water, and therefore gives a good
indication of eutrophication. A high BOD means lots
of organic material and aerobic microbes, i.e.
eutrophication
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9. JUNIOR

10. Before increases in nutrients:
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11. Acceleration of eutrophication :
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12. Results of eutrophication :
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13. JUNIOR

14. JUNIOR

15. Photo 1: Algal bloom in a lake.
Photo 1: Algal bloom in a lake.JUNIOR

16. Photo 2: Overgrowth of floating aquatic plants.
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17. Photo 3: Lake Biwa, the largest lake in Japan during
summer time showing overgrowth of aquatic plants.JUNIOR

18. Photo 4:
Fish
mortality
due to lack
of oxygen in
an
Indonesian
lake.
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19. Put in order the stages of Eutrophication!
LACK OF OXYGEN
GROWTH OF BACTERIA
DEATH OF PLANTS
SUFFOCATIONGROWTH OF PLANTS
ADDITION OF NITRATES
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