Question

The image shows a food web in an Arctic ecosystem.

Rising temperatures in the Arctic Ocean can lead to large die-offs of phytoplankton, which are autotrophs. What would most likely happen in an Arctic ecosystem if the phytoplankton population decreased?

A)the populations of all other organisms in the food web would decrease because there would be less energy available in the ecosystem.
B)the populations of krill and zooplankton would decrease, but no other organisms would be affected.
C)the populations of all other organisms in the food web would increase because there would be more energy available in the ecosystem.
D)the populations of zooplankton and krill would increase, but no other organisms would be affected.

Answer 1

The answer is A, because the phytoplankton is the foundation of this food web. Without your foundation, "the building will begin to crumble".

Answer 2

Answer: A)the populations of all other organisms in the food web would decrease because there would be less energy available in the ecosystem.

A food chain is a linear sequence of transfer of food and energy when one organism is consumed by other organisms. A food web is an interconnection of different food chains. One organism is dependent upon other organism for it's food requirement. In the given situation, the decline in the phytoplankton population will initially cause decline in the population of krill and zooplanktons but finally may also affect the population of other organisms which feed upon krill and zooplanktons. Therefore, the energy distribution in the food web will also be affected.