What is trophic efficiency equal to?
Trophic-transfer efficiency can be decomposed into consumption efficiency, assimilation efficiency, and production efficiency. Multiplying CE × AE × PE follows the successive fate of production: the fraction ingested, the fraction of ingested material absorbed, and the fraction of assimilated energy converted into consumer production. Because each term is a proportion below or equal to one, their product is smaller than any unconstrained input. Respired energy and unconsumed or egested material account for the major reductions. Substrate stoichiometry links carbon processing to nutrient demand
Ref: Fundamentals of Ecology, Odum & Barrett, 5th Ed., Ch. 3