Bicycle around the carbon cycle: Tiny Diatoms could offset global warming.

Bicycle around the carbon cycle: Tiny Diatoms could offset global warming.

About half the photosynthesis on earth occurs at sea, where tiny phytoplankton such as diatoms “fix” atmospheric carbon dioxide by converting it into organic matter. About 15% of this eventually sinks to the ocean depths, along with the diatom skeletons.

A 13-year study recently reported in PNAS revealed an unexpected and previously undocumented late summer deep sea sequestration of carbon by a symbiotic combination of cyanobacteria and diatoms. Although diatoms are tiny (about 30 could fit into the width of a human hair), their glass-like skeletons are heavy, so that when they die they take carbon out of the surface water, locking it into deep ocean sediments. Scientists speculate that the increase in day length could be a cue for the diatoms to begin sinking en masse, usually around August.

Carbon dioxide levels are higher now than the past 2.1 million years. Natural carbon sequestration by diatoms offers a welcome source of remediation.

Paper (open access):http://www.pnas.org/content/109/6/1842.full

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14 Responses to Bicycle around the carbon cycle: Tiny Diatoms could offset global warming.


  1. If somebody wants to research, there was a thesis on those diatoms by a scientist at Leiden university (nl) in about1992! (got his book!)


  2. Check wikipedia, lot of research links!


  3. Thanks Rajini Rao! You post more science in one post than NASA posts in a week 🙂

  4. Rajini Rao says:


    Shaker Cherukuri , diatoms can run out of micronutrients in the ocean. I came across a plan to seed more iron, which is difficult to come by in the ocean and needed for diatom reproduction. This could increase numbers of diatoms and so that they can sequester even more carbon dioxide.


  5. Is it possible to implement cynobacteria and diatoms cultivation in local water bodies other than oceans? If this is viable then the amount of reducing carbon dioxide will increase besides by oceans.


  6. i really fall in love with u, u do give me a lots ide on my work. i kind of admire what u have posted so far.

  7. Rajini Rao says:


    P. Murali Krishna , not sure if diatoms grow in fresh water, perhaps Chris Mallory knows more. On the other hand, diatoms can stick tenaciously to artificial (man made) structures in water to form a slimy, hard to remove coating. This is called biofouling. I’m guessing that we would not want them to grow in small bodies of water.

  8. Rajini Rao says:


    I’m happy to be labeled a scientist anywhere and anytime 🙂 The original list is a good one, but has only the early adopters of G+ and is overdue for an update. So many of us here now!

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