Eutrophication is when the environment of an
aquatic system becomes enriched with nutrients leading to a rapid growth of
aquatic plant life. When this happens, algae, plankton, and microorganisms that
are favour this condition will become large in quantity and they can take over.
Eutrophication can be caused by the discharge
of inorganic fertilisers such as nitrates and phosphates from agricultural
lands into rivers and lakes. Next, it can also be caused by untreated sewage
from the sewage treatment plants. Lastly, eutrophication can also be caused by
discharge of animal wastes into lakes and ponds.
BOD or otherwise known as biochemical oxygen
demand refers to the amount of oxygen that is required by aerobic biological
organisms to break down organic matter. The level of water pollution can be
easily measured by using BOD.
there is a large amount of organic matter in the water, the quantity of aerobic
bacteria needed to break down the waste is also high. Consequently, the
biochemical oxygen demand level will also be high.
Usually, the BOD level is an indication of the
level of water pollution. A high amount of dissolved oxygen will have a lower
BOD level, which indicates the good quality of the water. A low amount of dissolved oxygen will have a
higher BOD level which indicates the poor quality of the water.
CAUSES OF EUTROPHICATION
Eutrophication can be caused by natural causes
or even human activities. Among the natural causes that leads to eutrophication
are seasonal flooding, where the water washes up the nutrients to rivers, lakes
Fertilizer is one of the manmade causes that
leads to eutrophication. The fertilizers are used for farming purposes or even
for gardening purposes. Fertilizers often contain nitrogen, phosphorus and
potassium. These nutrients can easily be washed away to the nearest water
source causing a sudden rise in the nutrient value of the water source.
Untreated sewage can also be a major factor
hat causes eutrophication. Sewage often contains a high level of chemical
nutrients that may trigger eutrophication. Lastly, concentrated animal food is
also one of the causes as it is high I nitrogen and phosphorus. When the animal
food or their waste is released near a water source such as rivers and ponds,
it will cause eutrophication.
HOW IT OCCURS
nutrient content which has been deposited to the water source will cause the
aquatic plant such as phytoplankton to grow and increase in number rapidly,
which eventually result in algae bloom. The algae bloom will cause a change to
the normal ecosystem functions.
EFFECTS OF EUTROPHICATION
the effect of eutrophication is that it threatens the survival of aquatic
organisms like fish. This is because some algae produce toxins which are
harmful for consumption by living organism. The marine animals that feed on the
algae, they will die. Other land animals or birds that consume this tainted
water will also face the same consequences.
algal bloom which is highly toxic will also cause humans water and food sources
to be unusable. The water will no longer be appropriate to be used as drinking
water or even for other domestic purposes.as a result this may poison humans to
death or it may cause diseases such as diarrhoea. Furthermore, the marine
products such as fish, clams and seaweeds will no longer be safe for
consumption. In a way, if left out of control, this may even lead to
endangerment of marine products.
when algae and aquatic plants die they will encourage the growth of detritus.
The decomposition of detritus may use up all of the oxygen available in the
water source and hence resulting in the increase in the biochemical oxygen
demand. Many aquatic organisms will die as there is insufficient amount of
oxygen to live on.