Marine Biology

 Pyramid of Biomass

Biomass refers to the total weight of the living organisms in a unit area. An ecological pyramid of biomass shows the relationship between biomass and trophic level by quantifying the amount of biomass present at each trophic level. In the pyramid of biomass, there will be a clear cut decrease in the biomass from the lower to the higher trophic levels. Generally, the pyramid of biomass is an upright one (the apex is pointed upwards) in all terrestrial ecosystems. In certain ecosystems like pond ecosystem, the pyramid of biomass is an inverted type of pyramid (apex is pointed downwards). In this type of ecosystem, which contain less amount of biomass of producers and more amount of biomass of consumers (fishes).

Example: An Ocean Food Pyramid: It takes about 2500 pounds (1136 kg) of phytoplankton to support 0.5 pound (0.227 kg) of tuna. The decrease from 2500 to 500 is 80 percent. The other trophic levels in this pyramid are decreased by 90 percent. It is an upright pyramid of biomass.