Thanks for bringing this point up, I don't remember atmospheric N-fixing by algae being discussed before.
It seems you guessed correctly, at least for the blue-green species known as cyanobacteria: "Some species of blue-green algae do not need much of the nutrient nitrogen present in the water because they take in nitrogen from the air to grow. These ..." www.sjrwmd.com/streamlines/1999winter/fs_algae.pdf ...and the answer to your last question is yes, at least for seaweeds (which don't fix nitrogen from the air I don't think): "For centuries seaweed has been used as fertilizer. ..." en.wikipedia.org/wiki/Algaculture ...but it may be possible to use cyanobacteria to provide seaweeds with nitrogen by symbiosis, judging from the number of hits here: http://www.google.com/search?hl=en&q=symbiosis+cyanobacteria+seaweed&btnG=Google+Search ...so it may well make sense to cultivate both N-fixing and non N-fixing species in symbiosis in a Gyre scheme, using the cyanobacteria as nitrogen providers for the sargassum, or the sargassum as a floating support for the oil rich cyanobacteria depending which way you look at it... Jones will tell us if this makes sense. Michel ----- Original Message ----- From: "Michael Foster" <[EMAIL PROTECTED]> To: <vortex-l@eskimo.com> Sent: Tuesday, April 15, 2008 5:01 AM Subject: Re: [Vo]:CNN video of Vertigro algae factory > Jones wrote: >> >> I "want" them to be accurate (100,000 gallons per >> acre >> of oil and 700,000 pound of algae protein) but I fear >> that they are inflated. > > I had no idea algae were nitrogen fixating organisms, which they would have > to be to produce so much protein. I thought the bulk of the non-lipid > material would be cellulosic. What I'm getting at is that if the algae fixes > nitrogen from the air, it would make an excellent fertilizer for other crops. > Or is this already well-known? > > M.
