Biomass in ecology is the mass of living biological organisms in a given area, or ecosystem, at a given time. Biomass can refer to species biomass, the mass of one or more species, or to community biomass, the mass of all species in the community. It can include microorganisms, plants, or animals. The mass can be expressed as the average mass per unit area, or as the total mass in the community.
For example, in a salmon fishery, the salmon biomass might be regarded as the total wet weight the salmon would have if they were taken out of the water. In other contexts, biomass can be measured in terms of the dried organic mass, so perhaps only 30% of the actual weight might count, the rest being water. For other purposes, only biological tissues count, and teeth, bones, and shells are excluded.
Salmon, combined with all other fish on earth, with over 10,000 species, and global wet biomass is around 2000 million tonnes.
Of the single species, human’s total biomass is about 385 million tonnes. cattle, come in at about 520 million tonnes. Antarctic krill is at 379 million tonnes, Blue whales (pre-whaling) came in at 36 million tonnes but now are at 0.5 million tonnes, and chickens amass 48 million tonnes.
Some of the multiple species are ants (12,649 species) weigh in at 300 million tonnes, termites (2,800 species) at about 445 million tonnes, fish (10,000 species) at 2,000 million tonnes, but I was also surprised by earthworms (7,000 species) come in at a whopping 7,600 million tonnes.
Of all the mammals on Earth the wild ones, like lions, and tigers, and bears, and elephants, and zebras, and antelopes, and kangaroos, (you get it), make up only 4% of all the global biomass. Your pets come in at less than 1%.
- A tonne is a metric unit of mass equal to 1,000 kilograms. It is also referred to as a metric ton to distinguish it from the non-metric units of a short ton (U.S.), and long ton (Imperial). It is equivalent to approximately 2,204.6 pounds, 1.102 short tons, and 0.984 long tons. The official SI unit is the megagram (symbol: Mg), a less common way to express the same mass. [Back]