Look at an ocean system below. Phytoplankton
produce half of
the world's oxygen.
Shrimp feed on
plankton and also
need oxygen to live.
Salmon feed on
shrimp and need
oxygen to live.
People often eat
salmon. We also
need to breathe
oxygen to live.
What would most likely happen if the number of shrimp increased?

The population of phytoplankton will decrease, hence, resulting in a drop in oxygen production.

Explanation:

This question shows the activities that take place in an ocean habitat. The question is a typical example of a food chain where organisms feed on one another in order to obtain energy.

According to the question, the feeding relationship among the organisms is as follows:

Phytoplankton → Shrimp → Salmon → Humans

Phytoplankton, in this question, is said to produce half of the oxygen used on Earth. Hence, if the population of shrimps increased, it means that the population of phytoplanktons would decrease because there would be more shrimps to feed on them. This decline in the plankton population will cause a reduction in the world oxygen production.