Last update September 10, 2015
"Due to continuing growth in global shipping and no regulations regarding particles emissions over the open ocean, the input of potentially bioavailable iron from ship plumes is likely to increase during the next century. The model results suggest suggest that deposition of soluble iron from ships in 2100 contributes 30–60% of the soluble iron deposition over the high‐latitude North Atlantic and North Pacific".
in which Jeff Hecht writes:
GEOENGINEERING is being tested - albeit inadvertently - in the north Pacific. Soot from oil-burning ships is dumping about 1000 tonnes of soluble iron per year across 6 million square kilometres of ocean, new research has revealed.
Fertilising the world's oceans with iron has been controversially proposed as a way of sucking carbon dioxide out of the atmosphere to curb global warming. Some geoengineers claim releasing iron into the sea will stimulate plankton blooms, which absorb carbon, but ocean processes are complex and difficult to monitor in tests.
"Experiments suggest you change the population of algae, causing a shift from fish-dominated to jellyfish-dominated ecosystems," says Alex Baker of the University of East Anglia, UK. Such concerns led the UN Convention on Biological Diversity (CBD) to impose a moratorium on geoengineering experiments in 2010.
The annual ship deposition is much larger, if less concentrated, than the iron released in field tests carried out before the moratorium was in place. Yet because ship emissions are not intended to alter ocean chemistry, they do not violate the moratorium, says Jim Thomas of the ETC Group, a think tank that consults for the CBD. "If you intentionally drove oil-burning ships back and forth as a geoengineering experiment, that would contravene it."
"suggest that deposition of soluble iron from combustion sources contributes more than 40% of the total soluble iron deposition over significant portions of the open ocean in the Southern Hemisphere".
Atmospheric Processing of Combustion Aerosols as a Source of Bioavailable Iron
One more study:
Added May 3 (My emphasys)
September 10, 2015 (2)
(This may be related to the anthropogenic bioavailable iron from combustion)
Southern Ocean carbon sink bounces back with renewed vigour, study says
Sep 2015, 19:00 by Robert McSweeney - The Carbon Brief http://www.carbonbrief.org/blog/2015/09/southern-ocean-carbon-sink-bounces-back-with-renewed-vigour/
Delivery of anthropogenic bioavailable iron from mineral dust and combustion aerosols to the ocean
July 22, 2015
Natural aerosols explain seasonal and spatial patterns of Southern Ocean cloud albedo
Science Advances 17 Jul 2015: Vol. 1, no. 6, e1500157 DOI: 10.1126/sciadv.1500157
June 16, 2015