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Re: Cyano Preliminary Results
On Tue, 5 Jan 1999, Neil Frank wrote:
> >From: "Dixon, Steven T. (Exchange)" <stdixon at ben_bechtel.com>
> >Subject: Cyano Preliminary Results/long
> >First and foremost, green water and cyanobacteria are completely
> >different animals. <G> What we refer to as green water is not bacteria
> >at all, but unicellular algae. Karen pointed this out last week,
> >apparently to no avail.
> Green water and cyanobacteria are not necessarily different. Some "green"
> water _can_ be caused by unicellular species of cyanobacteria (blue green
> algae). The blue green algae that we usually think about is Oscillatoria
> and Lyngbya (the stuff which forms sheets).
I might add...
Not only can green water be caused by blue greens as well as green and
other algae, there also are probably hundreds if not thousands of
individual species that might cause it. Different species are different
sizes and have different requirements for light, nutrients, current, and
different defenses against predation. That might explain some of the big
variation we see in the conditions and cures for green water outbreaks.
Given that Neil can identify our normal cyanophyte plagues as probably
Oscillatoria or Lyngbya, can anyone produce a study indicating that
Oscillatoria and/or Lyngbya are capable of fixing nitrogen? I think our
oft-repeated statement that low nitrogen levels or low N:P ratios promote
cyanophyte outbreaks is based partly on the factoid that some cyanophytes
can fix nitrogen. I'd like to see more specific information.
In brittly dry and sunny Albuquerque.