What is depicted in the scheme shown below?

(N/A) The scheme illustrates an aquatic food chain.
It demonstrates the $10 \%$ law of energy transfer,which states that only $10 \%$ of the energy available at one trophic level is transferred to the next higher trophic level.
In this example:
- Phytoplankton $(400 \text{ kJ})$ $\rightarrow$ Zooplankton $(40 \text{ kJ})$
- Zooplankton $(40 \text{ kJ})$ $\rightarrow$ Smaller fishes $(4 \text{ kJ})$
- Smaller fishes $(4 \text{ kJ})$ $\rightarrow$ Big fish $(0.4 \text{ kJ})$
Each step shows a $10 \%$ transfer of energy from the previous level.