The proportion of energy transferred from one trophic level to the next is known as trophic level transfer efficiency or ecological efficiency. The Ten Percent law states that 'net production at one trophic level is generally only 10% of the net production at the preceding trophic level'. In this example, the producer contains 6000 units of energy. 10% of this will be transferred to the primary consumer, i.e. 600 units. In turn, 10% of this energy will be transferred to the secondary consumer i.e. 60 units.
