Algae are the producers in Yellowstone trophic levels which can be eaten by fish which is a primary consumer. The grizzly bear which is a secondary consumer or carnivores feed on these fish and when the grizzly bear die, fungi which is a decomposer feeds on the grizzly bear and release nitrogenous substances which can be used by the algae for its growth and development. Only 10% of energy is transferred from on trophic level to another whereas the remaining 90% are released in the form of heat energy.
