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I've rewritten this to fit better with the plankton page, and corrected some inaccuracies:

  • fungi are decomposers not photosynthesisers, so are not phytoplankton.
  • plankton do not 'hover', which implies an active process, but drift passively in the water column.
  • primary production is a term for the cumulative amount of carbon fixed per area over a period of time by phytoplankton.
  • some oceanic ecosystems are supplied by chemical energy from hydrothermal vents.

I've commented out some stuff about zooplankton and food chains - this should go in a zooplankton page. Agree?

There's a lot more I can add, which I will do in time...

Tonderai 20:52, 28 Nov 2003 (UTC)

== Page appears to have some vandalism. == it iz very dumb Ref to "stew fish peoplee" which doesn't look very scientific...

Fixed it - Vsmith 12:13, 17 July 2005 (UTC)

Atmosphereic Oxygen production Smackdown: Rainforest vs. Phytoplankton[edit]

This article says that phytoplankton produce approximately 98% of atmospheric oxygen. but the rainforest article says 40%. Which is right? How does the rain forests and phytoplankton relate to the carbon cycle? Can someone add to this article (or potentially the phytoplankton article) or add links to the correct source?

Good catch! This is a pretty common occurrence in presenting numbers and percentages and speaks directly to why we need to cite sources when writing articles that present such numerical "facts". Although we can trace by history who put that in, the point is, the contributer either pulled it out of his/her ass or got it from somewhere. It is not the kind of information that most scientists would have first-hand knowledge of. I will delete until a source can be provided. - Marshman 04:18, 3 September 2005 (UTC)
I figure it is important since I often hear the phytoplankton number tossed around by people who are more or less opposed to preserving the Rainforest. Thanks for the help!
Of course if a person thinks a good reason NOT to preserve the rainforewst is because phytoplankton produce all the oxygen we need, they won't be swayed by facts. But I understamnd your point - Marshman 23:54, 5 September 2005 (UTC)

Phytoplankton increasing global climate[edit]

hi,I was just reading an article that suggested that Phytoplankton are helping increase global climate, because they absorb radiation from the sun. I feel this information should be added to the article.

Increase global climate? You'll have to be clear about what you mean (for instance, you and I absorb radiation from the sun when we're outside during the day). I think what you mean is that they uptake carbon dioxide (from the ocean, but this exchanges with the atmosphere), so may have a role with respect to atmospheric CO2 and climate. It is almost certainly the case, however, that the terrestrial biosphere (trees, grasses, etc.) will have much more of a role in climate change in the future. Have a look at the carbon cycle article. Cheers, --Plumbago 09:40, 19 January 2006 (UTC)
My understanding is that phytoplankton cause global cooling because they reduce the amount of carbon dioxide in the atmosphere. —Preceding unsigned comment added by (talkcontribs)
Nthey are plants ope. They are not responding to increased CO2 as they are not limited by its availability. They are limited, primarily, by the availability of nutrients, which are ultimately supplied from deep water, and so may be affected by increased ocean stratification through warming. As it happens, the situation on land is very different. There, plants rely on the atmosphere for CO2 and generally obtain it at the expense of water. Anthro increases in atmospheric CO2 have made it easier for land plants to get hold of it, increasing their growth. So, while oceanic uptake of anthro CO2 is primarily via physico-chemical mechanisms, on the land uptake by biological processes is the primary mechanism. Of course, as the world warms up, processes such as respiration, which return CO2 to the atmosphere, will increase in rate, and several model studies suggest that the uptake of CO2 by the land will actually reverse within the current century. Some of this stuff is covered at biological pump and at primary production. Cheers, --Plumbago 08:25, 1 September 2006 (UTC)

Greek word[edit]

In the article Plankton it is written as πλανκτον. In this article, πλαγκτν. Which one is correct?

Good question. The first one seems to be a literal translation (π = pi = p; λ = lambda = l; ...; ν = nu = n), but the second seems to include γ (= gamma = g?), so seems to be wrong. However, I'm not entirely convinced by the literal translation either. According to a mates' PhD. thesis the name derives from the Greek for "wandering" (πλανκτος = planktos?), and was introduced by Victor Hensen in 1887. I don't have a proper reference for this, but I thought I'd best mention it in case someone else does. Hope this helps. Cheers, --Plumbago 10:32, 20 June 2006 (UTC)
Had a word with my mate, and he confirms that "planktos" is the root. He cites Victor Hensen via Thurman (1997, Introductory Oceanography, Prentice Hall College, New Jersey, USA, ISBN 0132620723). I'll make the appropriate changes. Cheers, and well spotted! --Plumbago 08:30, 21 June 2006 (UTC)
In Classical Greek orthography, the the nasal obstruent is velarized before a velar, therefore it is represented with γ. So, the form with gamma is correct. I have edited the article accordingly. CRCulver 21:24, 5 August 2006 (UTC)

For Robespierrester[edit]

Before doing any more revert please address the points below.

  • The reference with liink you provided is not responding when clicking on it.[1]
  1. ^ James Russell. "Live Phytoplankton". Retrieved 16 Dec 2006. Phytoplankton is a term that encompasses the autotrophic sector of aquatic microorganisms. Phytoplankton serves as the base of the marine food chain, providing a critical ecological function for all aquatic life. Most phytoplankton species are not classified as plants, despite their photosynthetic capabilities. Rather, these creatures are classified as protists, a phylogenetically more primitive organism 
  • The reference you are giving does not provide anything besides the general definition and quoting from a volatile web site is not what Wikipedia calls a valid source (please read Wikipedia litterature about that)
  • Why did you remove the last external link out (Plankton*Net) which is a real scientific resource ?

--Daniel Vaulot 19:46, 23 December 2006 (UTC)

The link works perfectly for me... what do you mean by not responding?
Can you provide me with a link to this piece of literature that says this site would not be a valid source?
Also, I did not mean to delete any other source, perhaps this was a result of the reversions and put into effect someone else's edits.
This definition is important because it covers a common misconception and also explains how broad this term really is.
The lines above have been added by Robespierrester (not signed though)

I have tried many times from France the link you provide and I was never able to reach the site. Second the quote is just a definition of phytoplankton and there is no need to use a quote from a commercial web site. Instead modifiying the definition and quoting from a book or from a scientific paper would be OK. --Daniel Vaulot 16:24, 5 January 2007 (UTC)


Is it true that phytoplankton populations are on the decline (and thus that the Earth's future atmospheric oxygen level is at risk)? Badagnani 06:44, 25 July 2007 (UTC)

The simple answer is "no". While phytoplankton abundance certainly varies, and there are good reasons to expect their numbers to fall somewhat in the future as the ocean stratifies because of global warming, I've never heard anyone question the future of Earth's oxygen atmosphere (and I work as a professional oceanographer). I'd love to know where this oxygen story comes from: the split in global primary production between land and ocean slightly favours land ecosystems (but the split is more pronounced on a per unit area basis because there's less than half as much land as there is ocean; see primary production). Given that almost all fixed carbon is respired back to CO2 (consuming O2) it's not at all obvious where the idea that that ocean's are "responsible" for our oxygen comes from. Further (and I'm treading well outside my expertise here), as I understand it (see this graphic), the majority of fossil fuel carbon has a terrestrial source, suggesting that geologically net primary production (that is, the extremely long-term balance between primary production and respiration) has been dominated by terrestrial production. Anyway, I'm going off on one now, so I'll stop!  ;-) Hope this helps. Cheers, --Plumbago 08:32, 25 July 2007 (UTC)

See this page and do a CONTROL-F search for "phytoplankton." Badagnani 09:04, 25 July 2007 (UTC)

Oh I've seen statements about this before, but not in reliable sources (this one certainly isn't reliable). I don't really keep on top of trends in phytoplankton, but I'm aware that there is some evidence for a recent decline. My understanding is that natural (i.e. non-anthropogenically forced) variability is not well-quantified, so that any declines observed may simply be part of a multi-year cycle. It's not something I work on myself, but I don't see fellow scientists rushing to study declining phytoplankton numbers, and I interpret that to mean it's not "interesting" (i.e. is most likely boring variability). Cheers, --Plumbago 09:14, 25 July 2007 (UTC)

As a nutritional supplement[edit]

This page mentions a nutritional supplement called "Marine Phytoplankton"]. Is this for real? If so, human consumption of phytoplankton for medicinal purposes should be added to the article. Badagnani (talk) 08:26, 19 December 2007 (UTC)

This website is selling it as powder or capsules. Badagnani (talk) 08:27, 19 December 2007 (UTC)

A number of companies market it as a nutritional supplement. (talk) 11:21, 29 June 2013 (UTC)

While this might be the case, unless there are solid sources supporting such medicinal use, we shouldn't be an advertising forum for potentially questionable products. Companies selling those already have their own marketing budgets. --PLUMBAGO 06:43, 30 June 2013 (UTC)

Ocean acidification[edit]

The effects on phytoplankton of increasing ocean acidification should be mentioned in the article. Badagnani (talk) 16:27, 28 January 2008 (UTC)!

hi olivia loyde love jace coby —Preceding unsigned comment added by (talk) 02:16, 16 November 2009 (UTC)

Why you insist to change the name of Persian Gulf?![edit]

 With all respect to the author of this article and those who have helped through the project,I should say you have done something bad and insulted geography science!By the way,the right name for what you have called "Arabian Sea" is "Persian Gulf". Please make it correct.

regards Ehsan Amozegar — Preceding unsigned comment added by (talk) 07:17, 11 October 2011 (UTC) Is the picture in the gallery the one that you are reffering to? I do believe that it shows both the Persian Gulf and the Arabian Sea. — Preceding unsigned comment added by ARandomFilipino (talkcontribs) 08:05, 7 November 2011 (UTC)

I've removed the offending photo. --Epipelagic (talk) 08:55, 7 November 2011 (UTC)

"As a side note ..."[edit]

In the section Ecology, first paragraph:

"As a side note, one of the more remarkable food chains in the ocean – remarkable because of the small number of links – is that of phytoplankton-feeding krill (a crustacean similar to a tiny shrimp) feeding baleen whales."

This sentence seems a bit awkward. Also: this seems more like a subjective statement.

Bhoya (talk) 21:56, 29 March 2012 (UTC)

Reference 4 is a dead link[edit]

Can someone who knows how to do this please update this dead link? (talk) 20:18, 5 January 2013 (UTC)

Atmospheric oxygen[edit]

I've just removed the assertion "Thus phytoplankton are responsible for much of the oxygen present in the Earth's atmosphere – half of the total amount produced by all plant life", and wanted to briefly expand on my reasoning. Basically, the source does not (strictly) support this statement. It says "Phytoplankton produce half of the oxygen generated by plants on Earth", but does not say anything about the source of oxygen in the Earth's atmosphere. For instance, if all of the oxygen produced by oceanic phytoplankton is consumed in short order by oceanic heterotrophs (and there are still uncertainty about whether the oceans are net heterotrophic or autotrophic), then it's arguable that they contribute little to the atmosphere. Contributions of oxygen to the atmosphere are driven by an imbalance between its production (through photosynthesis) and its consumption (through respiration), where a consistent bias in production over consumption would result in net oxygen accumulation - as well as organic carbon retention. And as the article on fossil fuel notes, most of the proven reserves are derived from terrestrial plants (in the form of coal), which is suggestive of land plants being more important over the long term than phytoplankton. All that said, it's not unlikely that my reasoning is wrong here, but before my change is reversed I'd suggest that we need a stronger source than a NASA publicity piece only tangentially related to this point. Cheers, --PLUMBAGO 10:03, 16 July 2014 (UTC)

Oceanography vs Limnology[edit]

I think perhaps there should be some sort of division between ocean phytoplankton and freshwater phytoplankton. While they're certainly all important, this article seems to focus on the oceans more than freshwater (there's only one mention of blue-green algae, even). Thus, someone searching for phytoplankton with an involvement in limnology is likely not to find the answers they need. Could someone correct this? Maybe divide the ecology section into two, and add to the freshwater explanation? — Preceding unsigned comment added by Sailor7sakura (talkcontribs) 20:34, 26 February 2015 (UTC)

Perhaps a freshwater section would suffice? It could explain what the key differences are between marine and freshwater phytoplankton. But it needs to be done carefully as (IMHO) they have more in common with each other than they have differences. Anyway, you seem to know what you're talking about, so have a go at writing something. Cheers, --PLUMBAGO 11:21, 27 February 2015 (UTC)