European Ocean Biodiversity Information System

The large-scale experiment EIFEX (European Iron Fertilisation Experiment) was conducted in the Antarctic Circumpolar Current to find out whether organic matter produced by algae is converted back into the greenhouse gas carbon dioxide in the surface layer or whether a substantial portion sinks out to the deep ocean which would mean long-term removal of carbon dioxide from the atmosphere. The nine-week experiment was organised and led by the AWI. On board were 53 scientists from 14 institutions and three companies from seven European countries and South Africa. The fertilisation was carried out 2200 km southwest of Cape Town. The team released a solution of iron sulphate in the propeller wash while Polarstern drew ever wider circles around a reference buoy. Seven tonnes of iron sulphate were necessary to fertilise an area of 150 km2 with a diameter of 14 kms. The resulting chemical and biological processes were measured round the clock by the team of experts.