The total global live biomass has been estimated at about 550 billion tonnes carbon,[1] most of which is found in forest trees.
Shallow aquatic environments, such as wetlands, estuaries and coral reefs, can be as productive as forests, generating similar amounts of new biomass each year on a given area.[2]

Biomass is the mass of living biological organisms in a given area or ecosystem at a given time. Biomass can refer to species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community. It can include microorganisms, plants or animals.[3] The mass can be expressed as the average mass per unit area, or as the total mass in the community.

How biomass is measured depends on why it is being measured. Sometimes, the biomass is regarded as the natural mass of organisms in situ, just as they are. 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. In some applications, biomass is measured as the mass of organically bound carbon (C) that is present.

In 2018, Bar-On et al. estimated the total live biomass on Earth at about 550 billion (5.5×1011) tonnes C,[1] most of it in plants. In 1998 Field estimated the total annual net primary production of biomass at just over 100 billion tonnes C/yr.[4] The total live biomass of bacteria was once believed to be as much as that of plants[5], but recent studies estimate it to be much smaller.[1][6][7][8][9] The total number of DNA base pairs on Earth, as a possible approximation of global biodiversity, is estimated at (5.3±3.6)×1037, and weighs 50 billion tonnes.[10][11] Anthropogenic mass (human-made material) is expected to exceed all living biomass on earth at around the year 2020.[12]

Ecological pyramids

An energy pyramid illustrates how much energy is needed as it flows upward to support the next trophic level. Only about 10% of the energy transferred between each trophic level is converted to biomass.

Main article: Ecological pyramid

An ecological pyramid is a graphical representation that shows, for a given ecosystem, the relationship between biomass or biological productivity and trophic levels.

An ecological pyramid provides a snapshot in time of an ecological community.

The bottom of the pyramid represents the primary producers (autotrophs). The primary producers take energy from the environment in the form of sunlight or inorganic chemicals and use it to create energy-rich molecules such as carbohydrates. This mechanism is called primary production. The pyramid then proceeds through the various trophic levels to the apex predators at the top.

When energy is transferred from one trophic level to the next, typically only ten percent is used to build new biomass. The remaining ninety percent goes to metabolic processes or is dissipated as heat. This energy loss means that productivity pyramids are never inverted, and generally limits food chains to about six levels. However, in oceans, biomass pyramids can be wholly or partially inverted, with more biomass at higher levels.

Terrestrial biomass

     Relative terrestrial biomasses
of vertebrates versus arthropods

Terrestrial biomass generally decreases markedly at each higher trophic level (plants, herbivores, carnivores). Examples of terrestrial producers are grasses, trees and shrubs. These have a much higher biomass than the animals that consume them, such as deer, zebras and insects. The level with the least biomass are the highest predators in the food chain, such as foxes and eagles.

In a temperate grassland, grasses and other plants are the primary producers at the bottom of the pyramid. Then come the primary consumers, such as grasshoppers, voles and bison, followed by the secondary consumers, shrews, hawks and small cats. Finally the tertiary consumers, large cats and wolves. The biomass pyramid decreases markedly at each higher level.

Changes in plant species in the terrestrial ecosystem can result in changes in the biomass of soil decomposer communities.[13] Biomass in C3 and C4 plant species can change in response to altered concentrations of CO2.[14] C3 plant species have been observed to increase in biomass in response to increasing concentrations of CO2 of up to 900 ppm.[15]

Ocean biomass

See also: Marine life

Ocean or marine biomass, in a reversal of terrestrial biomass, can increase at higher trophic levels. In the ocean, the food chain typically starts with phytoplankton, and follows the course:

Phytoplankton → zooplankton → predatory zooplankton → filter feeders → predatory fish

Ocean food web showing a network of food chains
Biomass pyramids
Compared to terrestrial biomass pyramids, aquatic pyramids are inverted at the base
Prochlorococcus, an influential bacterium

Phytoplankton are the main primary producers at the bottom of the marine food chain. Phytoplankton use photosynthesis to convert inorganic carbon into protoplasm. They are then consumed by zooplankton that range in size from a few micrometers in diameter in the case of protistan microzooplankton to macroscopic gelatinous and crustacean zooplankton.

Zooplankton comprise the second level in the food chain, and includes small crustaceans, such as copepods and krill, and the larva of fish, squid, lobsters and crabs.

In turn, small zooplankton are consumed by both larger predatory zooplankters, such as krill, and by forage fish, which are small, schooling, filter-feeding fish. This makes up the third level in the food chain.

A fourth trophic level can consist of predatory fish, marine mammals and seabirds that consume forage fish. Examples are swordfish, seals and gannets.

Apex predators, such as orcas, which can consume seals, and shortfin mako sharks, which can consume swordfish, make up a fifth trophic level. Baleen whales can consume zooplankton and krill directly, leading to a food chain with only three or four trophic levels.

Marine environments can have inverted biomass pyramids. In particular, the biomass of consumers (copepods, krill, shrimp, forage fish) is larger than the biomass of primary producers. This happens because the ocean's primary producers are tiny phytoplankton which are r-strategists that grow and reproduce rapidly, so a small mass can have a fast rate of primary production. In contrast, terrestrial primary producers, such as forests, are K-strategists that grow and reproduce slowly, so a much larger mass is needed to achieve the same rate of primary production.

Among the phytoplankton at the base of the marine food web are members from a phylum of bacteria called cyanobacteria. Marine cyanobacteria include the smallest known photosynthetic organisms. The smallest of all, Prochlorococcus, is just 0.5 to 0.8 micrometres across.[16] In terms of individual numbers, Prochlorococcus is possibly the most plentiful species on Earth: a single millilitre of surface seawater can contain 100,000 cells or more. Worldwide, there are estimated to be several octillion (1027) individuals.[17] Prochlorococcus is ubiquitous between 40°N and 40°S and dominates in the oligotrophic (nutrient poor) regions of the oceans.[18] The bacterium accounts for an estimated 20% of the oxygen in the Earth's atmosphere, and forms part of the base of the ocean food chain.[19]

Prokaryotic biomass

Prokaryotes are dived in two domains: bacteria and archaea. The global biomass of bacteria is far greater than the global biomass of archaea.[1] There are typically 50 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water[citation needed]. In a much-cited study from 1998,[5] the world prokaryotic biomass had been mistakenly calculated to be 350 to 550 billions of tonnes of carbon, similar to the amount of carbon in plants.[1][5] More recent studies of seafloor microbes cast considerable doubt on that; one study in 2012[6] reduced the calculated microbial biomass on the seafloor from the original 303 billions of tonnes of C to just 4.1 billion tonnes of C (range 1.5-22 billion tonnes), reducing the global biomass of prokaryotes to 50 to 250 billion tonnes of C. Further, if the average per-cell biomass of prokaryotes is reduced from 86 to 14 femtograms C,[6] then the global biomass of prokaryotes was reduced to 13 to 44.5 billion tonnes of C, equal to between 2.4% and 8.1% of the carbon in plants.

A census published by the PNAS in May 2018 gives for bacterial biomass ~70 billion tonnes of carbon, of which ~60 billion tonnes are found in the terrestrial deep subsurface.[1] Additionally, it estimated the global biomass of archaea at ~7 billion tonnes of carbon. A later study by the Deep Carbon Observatory project published in 2018 gives a smaller figure of 23 to 31 billion tonnes of carbon globally,[20] with roughly 70% found in the deep subsurface.[7][8][9] The estimated number of prokaryotic cells globally was estimated to be 11-15 × 1029. The authors of the May 2018 PNAS article reviewed their estimate in 2019 to around 30 billion tonnes of carbon as well.[21]

These estimates convert global abundance of prokaryotes into global biomass using average cellular biomass figures that are based on limited data. Recent estimates used an average cellular biomass of about 20-30 fgC per cell.[1][20][22]

Geographic location Number of cells (× 1029) Billion tonnes of carbon
Open ocean
1.7[5][6] to 10[5]
Ocean subsurface
(Assuming 21 fgC per cell)[20]
Terrestrial soil
3.7[5][6] to 22[5]
Terrestrial subsurface
2 to 6[20]
4 to 12
(Assuming 21 fgC per cell)[20]

Global biomass

External image
image icon Visualizing the biomass of life

Estimates for the global biomass of species and higher level groups are not always consistent across the literature. The total global biomass has been estimated at about 550 billion tonnes C.[23][1] Most of this biomass is found on land, with only 5 to 10 billion tonnes C found in the oceans.[23] On land, there is about 1,000 times more plant biomass (phytomass) than animal biomass (zoomass).[24] About 18% of this plant biomass is eaten by the land animals.[25] However, in the ocean, the animal biomass is nearly 30 times larger than the plant biomass.[26][dubious ] Most ocean plant biomass is eaten by the ocean animals.[25]

name number of species date of estimate individual count mean living mass of individual percent biomass (dried) total number of carbon atoms global dry biomass in million tonnes global wet (fresh) biomass in million tonnes
November 2022
8 billion[27]
50 kg
(incl children)[28]
4.63 billion adults
62 kg
(excl. children)[32]
1.3 billion[33]
400 kg
1.75 billion[34]
60 kg
24 billion
2 kg
107–108 billion[36]
3×10−6 kg
(0.003 grams)
1.3×106 billion[37]
3 g
0.486 g
10−6–10−9 kg
1×1031 cells[1]
23,000[7] – 70,000[1]

Humans compose about 100 million tonnes of the Earth's dry biomass,[46] domesticated animals about 700 million tonnes, earthworms over 1,100 million tonnes,[37] and annual cereal crops about 2.3 billion tonnes.[47]

Biomass by life form
Humans and their livestock represent 96% of all mammals on earth in terms of biomass, whereas all wild mammals represent only 4%.[1]

The most successful animal species, in terms of biomass, may well be Antarctic krill, Euphausia superba, with a fresh biomass approaching 500 million tonnes.[43][48][49] As a group, the family of lanternfish are among the most populous vertebrates, with some estimates suggesting that they may have a total global biomass of 550–660 million tonnes, accounting for up to 65% of all deep-sea fish biomass.[50] However, as a group, the small aquatic invertebrates called copepods may form the largest animal biomass on earth.[51] A 2009 paper in Science estimates, for the first time, the total world fish biomass as somewhere between 0.8 and 2.0 billion tonnes.[52][53] It has been estimated that about 1% of the global biomass is due to phytoplankton.[54]

According to a 2020 study published in Nature, human-made materials, or anthropogenic mass, outweigh all living biomass on earth, with plastic alone exceeding the mass of all land and marine animals combined.[55][12]

Global rate of production

Globally, terrestrial and oceanic habitats produce a similar amount of new biomass each year (56.4 billion tonnes C terrestrial and 48.5 billion tonnes C oceanic).

Net primary production is the rate at which new biomass is generated, mainly due to photosynthesis. Global primary production can be estimated from satellite observations. Satellites scan the normalised difference vegetation index (NDVI) over terrestrial habitats, and scan sea-surface chlorophyll levels over oceans. This results in 56.4 billion tonnes C/yr (53.8%), for terrestrial primary production, and 48.5 billion tonnes C/yr for oceanic primary production.[4] Thus, the total photoautotrophic primary production for the Earth is about 104.9 billion tonnes C/yr. This translates to about 426 gC/m2/yr for land production (excluding areas with permanent ice cover), and 140 gC/m2/yr for the oceans.

However, there is a much more significant difference in standing stocks—while accounting for almost half of total annual production, oceanic autotrophs account for only about 0.2% of the total biomass. Autotrophs may have the highest global proportion of biomass, but they are closely rivaled or surpassed by microbes.[56][57]

Terrestrial freshwater ecosystems generate about 1.5% of the global net primary production.[58]

Some global producers of biomass in order of productivity rates are

Producer Biomass productivity
Ref Total area
(million km2)
Ref Total production
(billion tonnes C/yr)
Swamps and marshes 2,500 [2] 5.7 [59]
Tropical rainforests 2,000 [60] 8 16
Coral reefs 2,000 [2] 0.28 [61] 0.56
Algal beds 2,000 [2]
River estuaries 1,800 [2]
Temperate forests 1,250 [2] 19 24
Cultivated lands 650 [2][62] 17 11
Tundras 140 [2][62] 11.5-29.8 [63][64]
Open ocean 125 [2][62] 311 39
Deserts 3 [62] 50 0.15

See also


  1. ^ a b c d e f g h i j k Bar-On YM, Phillips R, Milo R (June 2018). "The biomass distribution on Earth". Proceedings of the National Academy of Sciences of the United States of America. 115 (25): 6506–6511. Bibcode:2018PNAS..115.6506B. doi:10.1073/pnas.1711842115. PMC 6016768. PMID 29784790.
  2. ^ a b c d e f g h i Ricklefs RE, Miller GL (2000). Ecology (4th ed.). Macmillan. p. 192. ISBN 978-0-7167-2829-0.
  3. ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "biomass". doi:10.1351/goldbook.B00660
  4. ^ a b Field CB, Behrenfeld MJ, Randerson JT, Falkowski P (July 1998). "Primary production of the biosphere: integrating terrestrial and oceanic components". Science. 281 (5374): 237–40. Bibcode:1998Sci...281..237F. doi:10.1126/science.281.5374.237. PMID 9657713.
  5. ^ a b c d e f g h i Whitman WB, Coleman DC, Wiebe WJ (June 1998). "Prokaryotes: the unseen majority" (PDF). Proceedings of the National Academy of Sciences of the United States of America. 95 (12): 6578–83. Bibcode:1998PNAS...95.6578W. doi:10.1073/pnas.95.12.6578. PMC 33863. PMID 9618454.
  6. ^ a b c d e Kallmeyer J, Pockalny R, Adhikari RR, Smith DC, D'Hondt S (October 2012). "Global distribution of microbial abundance and biomass in subseafloor sediment". Proceedings of the National Academy of Sciences of the United States of America. 109 (40): 16213–6. Bibcode:2012PNAS..10916213K. doi:10.1073/pnas.1203849109. PMC 3479597. PMID 22927371.
  7. ^ a b c Deep Carbon Observatory (10 December 2018). "Life in deep Earth totals 15 to 23 billion tons of carbon -- hundreds of times more than humans - Deep Carbon Observatory collaborators, exploring the 'Galapagos of the deep,' add to what's known, unknown, and unknowable about Earth's most pristine ecosystem". EurekAlert!. Retrieved 11 December 2018.
  8. ^ a b Dockrill, Peter (11 December 2018). "Scientists Reveal a Massive Biosphere of Life Hidden Under Earth's Surface". Science Alert. Retrieved 11 December 2018.
  9. ^ a b Gabbatiss, Josh (11 December 2018). "Massive 'deep life' study reveals billions of tonnes of microbes living far beneath Earth's surface". The Independent. Retrieved 11 December 2018.
  10. ^ Landenmark HK, Forgan DH, Cockell CS (June 2015). "An Estimate of the Total DNA in the Biosphere". PLOS Biology. 13 (6): e1002168. doi:10.1371/journal.pbio.1002168. PMC 4466264. PMID 26066900.
  11. ^ Nuwer R (18 July 2015). "Counting All the DNA on Earth". The New York Times. New York. ISSN 0362-4331. Retrieved 18 July 2015.
  12. ^ a b Elhacham, Emily; Ben-Uri, Liad; et al. (2020). "Global human-made mass exceeds all living biomass". Nature. 588 (7838): 442–444. Bibcode:2020Natur.588..442E. doi:10.1038/s41586-020-3010-5. PMID 33299177. S2CID 228077506.
  13. ^ Spehn, Eva M.; Joshi, Jasmin; Schmid, Bernhard; Alphei, Jörn; Körner, Christian (2000). "Plant diversity effects on soil heterotrophic activity in experimental grassland ecosystems". Plant and Soil. 224 (2): 217–230. doi:10.1023/A:1004891807664. S2CID 25639544.
  14. ^ He, Jin-Sheng; Bazzaz, Fakhri A.; Schmid, Bernhard (2002). "Interactive Effects of Diversity, Nutrients and Elevated CO2 on Experimental Plant Communities". Oikos. 97 (3): 337–348. doi:10.1034/j.1600-0706.2002.970304.x. ISSN 0030-1299. JSTOR 3547655.
  15. ^ Drag, David W; Slattery, Rebecca; Siebers, Matthew; DeLucia, Evan H; Ort, Donald R; Bernacchi, Carl J (12 March 2020). "Soybean photosynthetic and biomass responses to carbon dioxide concentrations ranging from pre-industrial to the distant future". Journal of Experimental Botany. Oxford University Press (OUP). 71 (12): 3690–3700. doi:10.1093/jxb/eraa133. ISSN 0022-0957. PMC 7475242. PMID 32170296.
  16. ^ Kettler GC, Martiny AC, Huang K, Zucker J, Coleman ML, Rodrigue S, Chen F, Lapidus A, Ferriera S, Johnson J, Steglich C, Church GM, Richardson P, Chisholm SW (December 2007). "Patterns and implications of gene gain and loss in the evolution of Prochlorococcus". PLOS Genetics. 3 (12): e231. doi:10.1371/journal.pgen.0030231. PMC 2151091. PMID 18159947.
  17. ^ Nemiroff, R.; Bonnell, J., eds. (27 September 2006). "Earth from Saturn". Astronomy Picture of the Day. NASA.
  18. ^ Partensky F, Hess WR, Vaulot D (March 1999). "Prochlorococcus, a marine photosynthetic prokaryote of global significance". Microbiology and Molecular Biology Reviews. 63 (1): 106–27. doi:10.1128/MMBR.63.1.106-127.1999. PMC 98958. PMID 10066832.
  19. ^ "The Most Important Microbe You've Never Heard Of".
  20. ^ a b c d e f Magnabosco, C.; Lin, L.-H.; Dong, H.; Bomberg, M.; Ghiorse, W.; Stan-Lotter, H.; Pedersen, K.; Kieft, T. L.; van Heerden, E.; Onstott, T. C. (October 2018). "The biomass and biodiversity of the continental subsurface". Nature Geoscience. 11 (10): 707–717. doi:10.1038/s41561-018-0221-6. ISSN 1752-0908. S2CID 133768246.
  21. ^ Bar-On, Yinon M.; Milo, Ron (April 2019). "Towards a quantitative view of the global ubiquity of biofilms". Nature Reviews Microbiology. 17 (4): 199–200. doi:10.1038/s41579-019-0162-0. ISSN 1740-1534. PMID 30792541. S2CID 67789580.
  22. ^ Griebler, Christian; Mindl, Birgit; Slezak, Doris; Geiger-Kaiser, Margot (26 June 2002). "Distribution patterns of attached and suspended bacteria in pristine and contaminated shallow aquifers studied with an in situ sediment exposure microcosm". Aquatic Microbial Ecology. 28 (2): 117–129. doi:10.3354/ame028117. ISSN 0948-3055.
  23. ^ a b Groombridge B, Jenkins MD (2000) Global biodiversity: Earth’s living resources in the 21st century Page 11. World Conservation Monitoring Centre, World Conservation Press, Cambridge
  24. ^ Gosh, Iman (20 August 2021). "Misc All the Biomass of Earth, in One Graphic". Visual Capitalist. Retrieved 16 December 2021.
  25. ^ a b Hartley, Sue (2010) The 300 Million Years War: Plant Biomass v Herbivores Royal Institution Christmas Lecture.
  26. ^ Darlington, P (1966) "Biogeografia". Published in The Great Soviet Encyclopedia, 3rd Edition (1970–1979).
  27. ^ Nations, United. "Day of 8 Billion". United Nations. Retrieved 9 July 2023.
  28. ^ Hern, Warren M. (September 1999). "How Many Times Has the Human Population Doubled? Comparisons with Cancer". Population and Environment. 21 (1): 59–80. doi:10.1007/BF02436121. JSTOR 27503685. S2CID 86671730 – via JSTOR.
  29. ^ Jéquier, E.; Constant, F. (February 2010). "Water as an essential nutrient: the physiological basis of hydration". European Journal of Clinical Nutrition. 64 (2): 115–123. doi:10.1038/ejcn.2009.111. ISSN 1476-5640. PMID 19724292. S2CID 205129670.
  30. ^ Freitas, Robert A. Jr.Nanomedicine 3.1 Human Body Chemical Composition Archived 16 April 2018 at the Wayback Machine Foresight Institute, 1998
  31. ^ Greenspoon, Lior; Krieger, Eyal; Sender, Ron; Rosenberg, Yuval; Bar-On, Yinon M.; Moran, Uri; Antman, Tomer; Meiri, Shai; Roll, Uri; Noor, Elad; Milo, Ron (7 March 2023). "The global biomass of wild mammals". Proceedings of the National Academy of Sciences. 120 (10): e2204892120. doi:10.1073/pnas.2204892120. ISSN 0027-8424. PMC 10013851. PMID 36848563.
  32. ^ a b Walpole SC, Prieto-Merino D, Edwards P, Cleland J, Stevens G, Roberts I (June 2012). "The weight of nations: an estimation of adult human biomass". BMC Public Health. 12 (1): 439. doi:10.1186/1471-2458-12-439. PMC 3408371. PMID 22709383.
  33. ^ Cattle Today. "Breeds of Cattle at CATTLE TODAY". Retrieved 15 October 2013.
  34. ^ World's Rangelands Deteriorating Under Mounting Pressure Archived 11 March 2008 at the Wayback Machine Earth Policy Institute 2002
  35. ^ "Archived copy". Archived from the original on 15 February 2009. Retrieved 22 June 2012.((cite web)): CS1 maint: archived copy as title (link)
  36. ^ Embery J, Lucaire E, Karel H (1983). Joan Embery's collection of amazing animal facts. New York: Delacorte Press. ISBN 978-0-385-28486-8.
  37. ^ a b c d Blakemore RJ (2017). "Darwin's win-win for Global Worming?".
  38. ^ Lee KE (1985). Earthworms: their ecology and relationships with soils and land use. Sydney: Academic Press. ISBN 978-0-12-440860-9.
  39. ^ Sum of [(biomass m−22)*(area m2)] from table 3 in Sanderson, M.G. 1996 Biomass of termites and their emissions of methane and carbon dioxide: A global database Global Biochemical Cycles, Vol 10:4 543-557
  40. ^ Pershing AJ, Christensen LB, Record NR, Sherwood GD, Stetson PB (August 2010). Humphries S (ed.). "The impact of whaling on the ocean carbon cycle: why bigger was better". PLOS ONE. 5 (8): e12444. Bibcode:2010PLoSO...512444P. doi:10.1371/journal.pone.0012444. PMC 2928761. PMID 20865156. (Table 1)
  41. ^ a b Jelmert A, Oppen-Berntsen DO (1996). "Whaling and Deep-Sea Biodiversity". Conservation Biology. 10 (2): 653–654. doi:10.1046/j.1523-1739.1996.10020653.x.
  42. ^ Wilson, R. W.; Millero, F. J.; Taylor, J. R.; Walsh, P. J.; Christensen, V.; Jennings, S.; Grosell, M. (16 January 2009). "Contribution of Fish to the Marine Inorganic Carbon Cycle". Science. 323 (5912): 359–362. Bibcode:2009Sci...323..359W. doi:10.1126/science.1157972. PMID 19150840. S2CID 36321414. (This article provides a first estimate of global fish "wet weight" biomass)
  43. ^ a b Atkinson A, Siegel V, Pakhomov EA, Jessopp MJ, Loeb V (2009). "A re-appraisal of the total biomass and annual production of Antarctic krill" (PDF). Deep-Sea Research Part I. 56 (5): 727–740. Bibcode:2009DSRI...56..727A. doi:10.1016/j.dsr.2008.12.007.
  44. ^ Buitenhuis ET, Le Quéré C, Aumont O, Beaugrand G, Bunker A, Hirst A, Ikeda T, O'Brien T, Piontkovski S, Straile D (2006). "Biogeochemical fluxes through mesozooplankton". Global Biogeochemical Cycles. 20 (2): 2003. Bibcode:2006GBioC..20.2003B. doi:10.1029/2005GB002511. hdl:2115/13694. S2CID 18211589.
  45. ^ Garcia-Pichel F, Belnap J, Neuer S, Schanz F (2003). "Estimates of global cyanobacterial biomass and its distribution" (PDF). Algological Studies. 109: 213–217. doi:10.1127/1864-1318/2003/0109-0213.
  46. ^ The world human population was 6.6 billion in January 2008. At an average weight of 100 pounds (30 lbs of biomass), that equals 100 million tonnes.[clarification needed]
  47. ^ FAO Statistical Yearbook 2013: page 130 -
  48. ^ a b Nicol S, Endo Y (1997). Fisheries Technical Paper 367: Krill Fisheries of the World. FAO.
  49. ^ Ross, R. M. and Quetin, L. B. (1988). Euphausia superba: a critical review of annual production. Comp. Biochem. Physiol. 90B, 499-505.
  50. ^ Schwarzhans, Werner; Carnevale, Giorgio (19 March 2021). "The rise to dominance of lanternfishes (Teleostei: Myctophidae) in the oceanic ecosystems: a paleontological perspective". Paleobiology. 47 (3): 446–463. doi:10.1017/pab.2021.2. ISSN 0094-8373. S2CID 233678539.
  51. ^ "Biology of Copepods". Carl von Ossietzky University of Oldenburg. Archived from the original on 1 January 2009.
  52. ^ Wilson RW, Millero FJ, Taylor JR, Walsh PJ, Christensen V, Jennings S, Grosell M (January 2009). "Contribution of fish to the marine inorganic carbon cycle". Science. 323 (5912): 359–362. Bibcode:2009Sci...323..359W. doi:10.1126/science.1157972. PMID 19150840. S2CID 36321414.
  53. ^ Researcher gives first-ever estimate of worldwide fish biomass and impact on climate change, 15 January 2009.
  54. ^ Bidle KD, Falkowski PG (August 2004). "Cell death in planktonic, photosynthetic microorganisms". Nature Reviews. Microbiology. 2 (8): 643–655. doi:10.1038/nrmicro956. PMID 15263899. S2CID 15741047.
  55. ^ Laville, Sandra (9 December 2020). "Human-made materials now outweigh Earth's entire biomass – study". The Guardian. Retrieved 9 December 2020.
  56. ^ Whitman WB, Coleman DC, Wiebe WJ (June 1998). "Prokaryotes: the unseen majority". Proceedings of the National Academy of Sciences of the United States of America. 95 (12): 6578–83. Bibcode:1998PNAS...95.6578W. doi:10.1073/pnas.95.12.6578. PMC 33863. PMID 9618454.
  57. ^ Groombridge B, Jenkins M (2002). World Atlas of Biodiversity: Earth's Living Resources in the 21st Century. BMC Public Health. Vol. 12. World Conservation Monitoring Centre, United Nations Environment Programme. p. 439. doi:10.1186/1471-2458-12-439. ISBN 978-0-520-23668-4. PMC 3408371. PMID 22709383.
  58. ^ Alexander DE (1 May 1999). Encyclopedia of Environmental Science. Springer. ISBN 978-0-412-74050-3.
  59. ^[bare URL PDF]
  60. ^ Ricklefs RE, Miller GL (2000). Ecology (4th ed.). Macmillan. p. 197. ISBN 978-0-7167-2829-0.
  61. ^ Mark Spalding, Corinna Ravilious, and Edmund Green. 2001. World Atlas of Coral Reefs. Berkeley, California: University of California Press and UNEP/WCMC.
  62. ^ a b c d Park CC (2001). The environment: principles and applications (2nd ed.). Routledge. p. 564. ISBN 978-0-415-21770-5.
  63. ^ "Tundra - Biomes - WWF". World Wildlife Fund. Retrieved 5 October 2021.
  64. ^ "Tundra". ArcGIS StoryMaps. 17 January 2020. Retrieved 5 October 2021. the tundra is a vast and treeless land which covers about 20% of the Earth's surface, circumnavigating the North pole.

Further reading