Talk:Phytoplankton

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 Phytoplankton is within the scope of WikiProject Plants, an attempt to better organize information in articles related to plants and botany. For more information, visit the project page.
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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)

Contents

[edit] Page appears to have some vandalism.

Ref to "stew fish peoplee" which doesn't look very scientific...

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

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

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)

[edit] Phytoplankton increasing global climate

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 164.107.166.168 (talk • contribs)
Nope. 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)

[edit] Greek word

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)

[edit] For Robespierrester

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 (En). Retrieved on 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)

[edit] Disappearing?

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)

[edit] As a nutritional supplement

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)

[edit] Ocean acidification

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