Volcanic ash contains Iron and many other trace metals and also some Silica. Sahara dust contains Silica, Phosphorus, Iron and other trace metals.
So dosing ONLY Iron is not a complete solution.
Unfortunate that the discussion is not going beyond Iron Fertilization.
The key issue is the objective of Ocean Fertilization, it is to grow Diatom Algae.
Growing Diatoms in the 12 mile zone from the coast will be extremely beneficial and
this will demonstrate that growing Diatoms is beneficial.
Growing Diatoms using the Nutrients in Sewage and Fertilizer runoff
is the best solution to prevent the bloom of Cyanobacteria and Dinoflagellates / Red Tides.
Sewage and Fertilizer runoff is causing Algal Blooms, eutrophication, hypoxia, etc.,
in coastal waters and Lakes, this is the reason why most people are skeptical about Ocean Fertilization.
So any Ocean Fertilization solution has to first demonstrate that it can solve this problem.
Coastal waters have all the inputs required for phytoplankton growth - N, P, K, Si, Fe, etc.,
and Algae do bloom, but these algal blooms are causing problems.
We need to grow Diatoms and demonstrate that they are the solution to Nuisance and Harmful Algal Blooms.
Regards
Bhaskar
Director
Kadambari Consultants Pvt Ltd
Hyderabad. India