Succession is a process that occurs in natural ecosystems. Describe and explain how ecological succession occurs.
Figure 1 shows percentages of energy transferred from sunlight to a sea urchin in a marine kelp forest ecosystem.

Use Figure 1 to calculate the percentage of sunlight energy that is transferred to the respiration of a sea urchin. Give your answer to 3 significant figures.
In this ecosystem, the net primary productivity of the kelp forest is 48 200 kJ m−2 year−148\,200\text{ kJ m}^{-2}\text{ year}^{-1}48200 kJ m−2 year−1.
Use this information and Figure 1 to calculate the energy lost in faeces and chemical waste of the sea urchins in kJ m−2 year−1\text{kJ m}^{-2}\text{ year}^{-1}kJ m−2 year−1. Give your answer to 3 significant figures.