Question

In most terrestrial ecosystems the production pyramid has the same shape as the biomass pyramid – there is more production and biomass in the primary producers than in the primary consumers. In some aquatic ecosystems the biomass pyramid can be inverted because.

Answer 1

In some aquatic ecosystems, the biomass pyramid can be inverted because the biomass of organic matter at lower tropic level is lesser than the organic matter biomass at higher tropic level.

This is because phytoplankton are smaller than their consumers who are zooplanktons. Zooplankton is smaller than secondary consumer krills and small fishes and these small fisher are smaller than tertiary consumers like shark, killer whales.

Short life span of lower trophic level organisms is also a reason for lower biomass at lower trophic levels. This makes the pyramid of biomass inverted in some aquatic ecosystems.