Editing Antarctic krill (section)

===Biological pump and carbon sequestration===
[[File:Krillspitballkils3.jpg|thumb|''In situ'' image taken with an [[ecoSCOPE]]. A green spitball is visible in the lower right of the image and a green fecal string in the lower left.]]
Krill are thought to undergo between one and three vertical migrations from mixed surface waters to depths of 100&nbsp;m daily.<ref>{{cite journal |author1=Geraint A. Tarling |author2=Magnus L. Johnson |title=Satiation gives krill that sinking feeling |journal=[[Current Biology]] |volume=16 |issue=3 |pages=83–84 |year=2006 |pmid=16461267 |doi=10.1016/j.cub.2006.01.044|doi-access=free |bibcode=2006CBio...16..R83T }}</ref> The krill is a very untidy feeder, and it often spits out aggregates of [[phytoplankton]] (spitballs) containing thousands of cells sticking together. It also produces fecal strings that still contain significant amounts of [[carbon]] and [[glass]] shells of the [[diatom]]s. Both are heavy and sink very fast into the abyss. This process is called the [[biological pump]]. As the waters around [[Antarctica]] are very deep ({{convert|2000|-|4000|m|disp=or}}), they act as a [[carbon dioxide sink]]: this process exports large quantities of carbon (fixed [[carbon dioxide]], CO<sub>2</sub>) from the biosphere and [[Carbon Sequestration|sequesters]] it for about 1,000&nbsp;years.
[[File:Pelagiczone.svg|thumb|378x378px|Layers of the Pelagic Zone which contains organisms that make up an ecosystem. Antarctic Krill  are part of this ecosystem.]]
If the phytoplankton is consumed by other components of the pelagic ecosystem, most of the carbon remains in the upper layers of the ocean. There is speculation that this process is one of the largest biofeedback mechanisms of the planet, maybe the most sizable of all, driven by a gigantic biomass. Still more research is needed to quantify the Southern Ocean ecosystem.