The German research vessel Polarstern is making way from Cape Town towards the Southwest Atlantic Sector of the Southern Ocean where scientists intend to dump iron into the ocean in an experiment to determine the effects of fertilizing algae growth on the ecology and carbon uptake. The ship carries an international team of scientists from Germany, India and Chile. The cooperative project is named LOHAFEX, after the Hindi word for iron, LOHA, and FEX for Fertilization EXperiment. The experiment entails spreading 20 tons of iron sulphate over 300 square kilometers of ocean. Some raise charges of "rogue" science while others laud controlled research they believe warranted by the urgency of climate change. What can be learned and what could go wrong?What Can be Learned?
After spreading the iron, the Polarstern will collect water samples with special equipment like the rosette shown here. Five experiments have been conducted in these waters, two by Polarstern in 2000 and 2004. This time, more parameters will be studied for longer, and the area to be fertilized is expected to be more productive because it contains colonies of phytoplankton carried in on coastal currents. Scientists hope to learn:
- if the decline of Antarctic penguins, seals and whales are due to dropping supplies of the tiny ocean shrimp, krill, in response to declining plankton levels;
- whether enhanced phytoplankton growth has the potential to isolate a gigaton, or one trillion kilograms, of carbon dioxide every year;
- the impact of the phytoplanktion growth on the ecology of surrounding areas, and
- the fate of the phytoplankton, which is beneficial only if it sinks to the ocean depths, dragging carbon down with it.
What Could Go Wrong?
Naysayers paint nightmare scenarios, pointing to past failures in eco-tinkering. Iron fertilization could alter marine food chains, dramatically changing the balance of species. Out of control plankton blooms could block sunlight needed by coral reefs or create ocean dead zones. In a terribly ironic turn of events, iron fertilization could even produce greenhouse gases more potent than carbon dioxide, such as nitrous oxide and methane.
A typical diatom, Chaetoceros sp., and a phytoplankton community three weeks after fertilization. Image: AWI
Furthermore, skeptics have estimated that the maximum carbon sequestration potential from ocean fertilization is 1 billion tons, or 15% of total carbon dioxide emissions, not sufficient to justify taking risks with the oceanic ecosystems. They argue that energies are better focused on renewables and reducing emissions, and ocean fertilization distracts from the real work to be done.
The truth is, there is not enough data available to make a good decision. And while few scientists are ready to embrace large scale oceanic tinkering, few would argue that controlled and measured experimentation should not be one front in addressing a challenge that itself poses nightmare scenarios beyond our wildest imaginations. Additional support accrues to projects conducted by respected, independent scientists rather than commercially motivated projects with an eye on the estimated US$100 billion value of carbon credits from ocean sequestration.
More on Polarstern:
LOHAFEX: An Indo-German iron fertilization experiment
International Team Of Scientists To Test South Atlantic Carbon Sink In 2009
Hot Spot Sight-Seeing
More on Iron Fertilization of Oceans:
Ocean Iron Fertilization Test in South Atlantic Given Go Ahead
Think Ocean Geo-Engineering is a Good Idea? Think Again, Scientists Urge
Where We Stand on Iron Fertilization
German Scientist Outlines Massive Iron Fertilization Plan to Save the Antarctic
What Would Be the Side Effects of Iron Fertilization?