Energy Loss Between Trophic Levels
Losses of energy
- Not all energy is transferred from one trophic level to the next
- Approximately, only 10% of the energy of each trophic level is passed on to the next
- This is why food chains are rarely made up of more than six trophic levels – the total amount of energy available eventually becomes too small to support another trophic level
Energy/biomass is lost at each trophic level for several reasons
- Losses of energy are due to:
- Organisms rarely eat every part of the organism they are consuming – some of the biological material of plants and animals may be inedible (eg. many predators do not consume the bones of their prey)
- Not all the ingested material is digested and absorbed, some is egested as faeces
- Energy is used for movement
- Energy is used to generate heat
- Energy is used for metabolic processes
- Some absorbed material is lost as waste:
- Carbon dioxide and water are waste products of respiration
- Water and urea are the waste products in the urine, which is produced when proteins are broken down
