Experimental Iron Fertilisation of the Oceans

From 1993-2002, 7 scientific expeditions fertilised small patches of the major HNLC areas of the world with iron.

(Key below. SoFex (H) and SEEDS (G) both seeded 2 separate areas in the same expedition, while (J), Planktos, was a private venture with no results publicly available. Although promised them via private e-mail, none appeared.)

The first 2 experiments (IronEx I and II, A and B) were the simplest, but gave stunning results - largely because the clearly-visible reaction was seen for the first time. The clear blue oceans turned into "pea-soup" for miles, and experimenters could smell the change.

Check image under "The Practice" to see the ocean "Before and After" within: Summary.htm

Later expeditions comprised international teams of 100's of scientists, studying different aspects of biogeochemistry.

From the 100's of papers detailing experimental results, it is clear that:

• Iron is indeed a limiting nutrient in HNLC areas. In SEEDS, fertilisation produced a 40-fold chlorophyll increase.
• Additional carbon dioxide is drawn-down from the atmosphere by resultant phytoplankton blooms
• Other gases are produced (e.g. DMS), and other limiting nutrients (nitrates and phosphorous) are used up.
• Marine communities change. In the South, diatoms are favoured over flagellates, and in the North, centric diatoms over pennate.

What has *not* been found is any proof that any additional carbon sinks to the ocean floor and gets buried, thus entering long-term storage.

My own summary of the experimental results can be accessed at: http://www.bbm.me.uk/FeFert/experiments.htm

Future experiments

The Alfred Wegener Institute plan a follow-up to their EisenEx project, the European Iron Fertilisation EXperiment (EIFEX). Its main aim is to 'understand the functioning of pelagic ecosystems'. It is scheduled for January 20th - March 26th 2004, in approximately the same area as EisenEx.

Summary

A professional summary of the experiments to date:

References

Diatom Image from 'The effect of in situ iron addition on the sinking rates and export flux of Southern Ocean diatoms', Waite and Nodder, Deep Sea Research Part II, Topical Studies in Oceanography, Volume 48, issues 11-12, 2001. Accessed from Science Direct: http://www.sciencedirect.com

Summary Table adapted from US JGOFS Newsletter October 2002 (page 9) http://usjgofs.whoi.edu/general_info/vol121.pdf

Home Page Home.htm

Overview and Introduction: Introduction.htm

Alternative Views and Motivation: Alternative.htm

Evidence of Natural Iron Fertilisation Evidence.htm

** Current page ** Experiments.htm

FAQ - Will it Work? etc FAQ.htm

Solution and Conclusion Solution.htm