November 2021

The biomass of life on earth


The biomass of life on earth

The term biomass means the total weight or quantity of a certain species, or order of species. In this article we are going to look at the vast biomass of different things on the planet, and how we make up such a really small part of it as humans.

So far, we know that there are around 8,7 million species on the planet. When we break down this composition it really does become rather fascinating. We measure the biomass by the amount of carbon each organism contains. Carbon is the main component that makes up every organism.

Let’s have a look at the numbers: These numbers are measured in gigatons ( 1 000 000 000 kg = 1 gigaton).

  • Marine arthropods are invertebrate animals with segmented bodies and exoskeletons. They includes crabs, lobsters and shrimps their total weight is around 1 gigaton.
  • More than 33 000 fish species make up 0.7 gigatons.
  • Annelids which include earthworms, leeches and ragworms make up around 0.2 gigatons.
  • Arthropods (terrestrial) which include spiders, centipedes, butterflies etc. make up 0.2 gigatons.
  • Molluscs (snails, squids and octopus) make up 0.2 gigatons.
  • Cnidarians (jellyfish, sea anemones, corals etc) make up 0.1 gigatons.
  • Livestock (cows, pigs, chickens) make up 0.1 gigatons.
  • Humans, a surprisingly small amount of biomass at only 0.06 gigatons.
  • Nematodes (they are classified as insects and include roundworms, eelworms, and parasitic species such as ascaris) make up 0.02 gigatons.
  • Wild animals make a very small amount of biomass (this would have been a lot more two centuries ago) at only 0.007 gigatons.
  • Wild birds only make up 0.002 gigatons.

With all this said, we are by far the most advanced species on the planet, and it is shown that we have a lot of other species weight to carry on our shoulders.

By Quentin Swanevelder
Field Guide