Use the following scenario to answer the next following question(s):

You and your friends go to the beach for vacation. You all walk down to the beach to go swimming. When you get there, you see the water is murky and green, and there are algae blooms floating on top.

Reference: Ref 6-3

If it is excess nutrients which are feeding the algae blooms and lowering the oxygen content in the water, that process is called:
A. nutrient cycling.
B. nitrification.
C. eutrophication.
D. hypoxia.

Eutrophication refers to a situation in which the aquatic environment becomes excessively enriched with nutrients. This leads to algal blooms in aquatic habitats such as lakes. These nutrients come from Fertilisers used in farming, which find their way into water bodies through run-off thereby increasing nutrient levels.

Excess nutrients causes phytoplankton to grow and reproduce at an alarming rate resulting in algal blooms. This bloom disrupts the balance in the ecosystem leading to many problems.

The algae may end up using all the oxygen in the water, causing oxygen shortage for aquatic life. Some of the algae may die, their decay may lead to further oxygen depletion. As oxygen is depleted, aquatic organisms may also begin to die.