Hello, Dan, I think we are in really deep water here. The marine scientists are just beginning to understand what's going on with open ocean phytoplankton. I was captivated by work being done by Irina Marinov and others at Woods Hole while she was a post-doc there, showing how other nutrients have a critical role in how iron is used. She is now at U. of Penn. _http://www.sas.upenn.edu/earth/marinov_r.html_ (http://www.sas.upenn.edu/earth/marinov_r.html) I think to really understand the goings-on with phytoplankton, it would be good to talk with someone like her or dig into the recent literature. I think she was involved (not sure) with showing how the toxic blooms are connected with insufficient dissolved silica in the water. Natural surface fertilization usually involves application of iron-rich silica, say from dust storms or colloidal minerals from glaciers. (That's my understanding, could be way off) Silica shifts the productivity into diatoms which are the bottom rung of the ocean food chain. As far as I know, no OIF experiments involved adding finely-divided silica with the iron. I am very concerned about the acidification of sea water since silica solubility decreases with decreasing pH. I wonder if this has a bearing on the falling oxygen concentration in sea water and the more frequent hypoxia events in recent decades. My personal view is that ocean productivity is the real key to practical geoengineering by way of CO2 removal. But you will find many that would disagree. Ernie Rogers In a message dated 3/15/2010 3:15:42 P.M. Mountain Daylight Time, [email protected] writes:
A PNAS paper was released today commenting on studies finding domoic acid in some of the samples from previous OIF projects. A variety of articles have commented. http://www.nature.com/news/2010/100315/full/news.2010.124.html http://www.nytimes.com/2010/03/16/science/16obiron.html http://news.discovery.com/earth/geoengineering-carbon-sequestration-phytopla nkton.html I commented here: http://climos.com/note_detail.php?pid=174 A PNAS paper released today which looks at domoic acid (DA) production in past OIF experiments has concluded that DA was increased in some of the projects. Though the conclusions from the paper itself were relatively conservative... "Although there remain uncertainties in extrapolating our results to large oceanic scales, the findings establish potential consequences for developing toxic phytoplankton blooms in pelagic ecosystems, which so far have not been adequately investigated." Headlines have ranged from the dramatic "Ocean Geoengineering Scheme May Prove Lethal", and at the NY Times, the oddly phrased, "A Risk of Poisoning the Deepest Wells" to the more subdued, "Carbon-capture scheme could cause toxic blooms". All fail to explore the obvious. Namely, that phytoplankton underpin open ocean productivity, that this productivity relies on iron, and that when iron-fed naturally occurring blooms happen, they likely favor--in certain regions--Pseudonitzschia or other DA producers. In short, we know that the availability of iron drives much of the oceanic carbon cycle. If DA is produced by artificially stimulated OIF blooms, it is likely produced during natural ones as well. Moving forward, we need to understand exactly how deep-ocean phytoplankton respond to iron--be it naturally or artificially supplied, whether and in what situations DA is produced, and how the ecosystem is or is not already adapted to this. If it occurs naturally, are organisms that live there used to blooms containing DA? In past climate cycles, when productivity in the deep ocean was much greater, was DA characteristic as well? These are questions that remain unresolved and need well defined research programs to address. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
