Here's why:

* Biomass refers to the total mass of living organisms in a given area.

* Pyramid of biomass represents the amount of biomass at each trophic level.

* Top predators are the organisms at the highest trophic level, meaning they consume other organisms but are not preyed upon by anything else.

Since top predators have fewer individuals than the organisms they prey upon, their biomass is smaller. This results in a smaller base at the top of the pyramid.