LOHAFEX was an experiment to add iron to the ocean, planned by the Council of Scientific and Industrial Research in India and the Helmholtz Association in Germany. The goal was to test if adding iron would cause algae to grow rapidly and capture carbon dioxide from the air. Although algae did grow, the bloom was not as large as expected. Most of the algae were eaten by tiny sea animals instead of sinking to the bottom of the ocean, so very little carbon dioxide was removed from the atmosphere for a long time. This result made it harder to use ocean iron fertilization as a way to reduce carbon dioxide emissions.
Background
The experiment was based on an agreement signed on October 30, 2007, by Dr. T. Ramaswami, Director General of CSIR, and Dr. Juergen Mlynek, President of the Helmholtz Foundation in Germany. This agreement focused on cooperation in marine sciences and was signed during the visit of German Chancellor Angela Merkel to India. The experiment was led by the CSIR-National Institute of Oceanography (NIO) in Goa, India, and the Alfred-Wegener Institute for Polar and Marine Research (AWI) in Bremerhaven, Germany. Scientists from Chile, France, Spain, and the United Kingdom also participated. The German research ship Polarstern was used during its ANT XXV/3 cruise. The experiment was jointly directed by Wajih Naqvi of CSIR-NIO and Victor Smetacek of AWI. Weekly reports about the expedition were published on the AWI website.
Course of the experiment
A cyclonic eddy located at 48 degrees south, 16 degrees east was chosen for the experiment. The study started on India's Republic Day, which is 26 January 2009. Scientists spread 10 tonnes of ferrous sulfate dissolved in seawater over an area of 300 square kilometers. This area was observed for 38 days to study how adding iron affects ocean chemistry and marine life. A second similar amount of iron was added two weeks later. Scientists expected that adding iron would cause algae to grow rapidly, which could help remove carbon dioxide from the air.
The research ship departed from Cape Town on 7 January 2009. The expedition lasted 70 days and ended on 17 March 2009 in Punta Arenas, Chile.
Opposition and protests
After several organizations raised concerns, the German government stopped the experiment. Environmental groups were worried that a man-made algal bloom could harm the ocean's ecosystem. Critics said that the long-term impacts of adding nutrients to the ocean could not be seen in short-term studies. Others were concerned that large experiments to change the environment might lead to big changes in ecosystems. The German government sent the plan to scientists and legal experts for review. Both groups supported the project, and the experiment was allowed to continue.
Prior experiments
LOHAFEX was not the first experiment of its kind. In 2000 and 2004, similar amounts of iron sulfate were released from the same ship during the de:EisenEx experiment. Ten to twenty percent of the algal bloom died and sank to the sea floor. This process removed carbon from the atmosphere, achieving the planned carbon sink effect.
Results
During the LOHAFEX experiment, iron fertilization caused an algal bloom, but the increase in chlorophyll, which shows how much plant life was present, was smaller than in earlier studies. The algal bloom helped zooplankton grow, as these tiny animals eat the algae. Zooplankton are then eaten by larger sea creatures. This means adding iron to the ocean can help rebuild fish populations that have been reduced by overfishing, because it supports the growth of marine life that removes carbon dioxide from the atmosphere. Increasing the amount of plant life in the ocean through large-scale iron fertilization could lead to more marine life.
Unlike other experiments, such as EisenEX, the zooplankton in LOHAFEX consumed most of the algae. This left little organic carbon to sink to the ocean floor. As a result, the iron added during the experiment did not help store carbon dioxide from the air in the deep ocean.