Construct a pyramid of biomass starting with phytoplankton. Label three trophic levels. Is the pyramid upright or inverted? Justify your answer.

The pyramid of biomass starting with the phytoplankton is an inverted pyramid.

This is because the biomass of fishes (SC) exceeds the biomass of Zooplanktons (PC) which in turn exceeds the biomass of phytoplanktons (PP).