Early results from the LOHAFEX experiment suggest that very little carbon was sequestered because the phytoplankton bloom did consist of diatoms. Diatoms have silica shells that both resist predation by copepods and cause the diatoms to sink rapidly upon their death. Unfortunately, LOHAFEX fertilized a patch of ocean very low in silica content. Prior ocean fertilization experiments, including the 2004 EiFEX experiment led by the same Dr. Victor Smetacek of LOHAFEX, had more silicic acid and observed much higher rates of carbon sequestration.
Coverage can be found at
New Scientist article
and the BBC article
Dr. Ken Coale comments in the BBC article:
But Kenneth Coale, director of Moss Landing Marine Laboratories in California, who has led several iron fertilisation experiments, said the initial burst of phytoplankton growth was consistent with previous findings.
"To date we've conducted experiments in what amounts to 0.04% of the ocean's surface," he told BBC News.
"All have indicated that iron is the key factor controlling phytoplankton growth, and most have indicated that there is carbon flux (towards the sea floor) - this is one that didn't."
A key aim for the future, he said, was to understand better the various ecosystems contained in the ocean in order that fertilisation could be conducted in areas containing the "right" kinds of organism.