Compare these 2 ponds, the bottom
one experiencing eutrophication.
When lakes, streams
and estuaries are
organic matter can
become a water
problem and as a
process can be
However, humans in their everyday activities
can exacerbate the process:
Point sources (can locate the cause)
Sewage treatment plant discharges
Storm sewer discharges
Non-point sources (can’t locate the cause,
Agricultural runoff (fertilizer, soil erosion)
1. Fertilizer flows into water
2. Increased plant growth on the surface
3. Decreased light in lower levels of water,
4. Plants in lower levels of water
to die, causing….
5. Decay using up O2 and increasing
6. Death of fish and other animals.
LACK OF OXYGEN
GROWTH OF BACTERIA
DEATH OF PLANTS
GROWTH OF PLANTS
ADDITION OF NITRATES
Eutrophication process in 6 stages
Before increases in nutrients:Before increases in nutrients:
These fish died due to Eutrophication
removing the oxygen.
Photo 1: Algal bloom in a lake.
Algal bloom in a lake.
due to lack
of oxygen in
or "harmful algal
are toxic to
Blue Baby Syndrome - An illness that begins when
large amounts of nitrates in water are ingested by
an infant and converted to nitrite by the digestive
system. He nitrite then reacts with ox hemoglobin
(the oxygen-carrying blood protein) to form
metheglobin, which cannot carry oxygen. If a large
enough amount of metheglobin is formed in the
blood, body tissues may be deprived of oxygen,
causing the infant to develop a blue coloration of
their mucous membranes and possibly digestive
and respiratory problems. This condition is also
known as methemoglobinemia.
Eutrophication can be avoided by using
minimal required amounts of chemical
fertilizers or better still do away with them and
use natural ones instead. Be sure not to have
the fields close to the water bodies. Take
extra care while using fertilizers during
monsoons as due to run - off, they get
transmitted to the water bodies. Then , they
can cause blockage of water ways, death of
marine life n breakage of food chain.