Are iron fertilisation experiments in the ocean necessary from a scientific perspective?

Stefan Hain: Yes, because there are still several gaps in our scientific knowledge on the past, present and future role of this essential element on organisms, the entire food web and the carbon cycle. Hypotheses and assertions of a more or less scientific nature exist. However these can only be checked in the laboratory or using models to a limited extent, because the natural processes and interactions in the sea are far too complex for this. It is only possible to test individual organisms in the laboratory, but not the interaction of several factors. The way relationships of organisms alter with respect to each other in the food web and the material flow, in other words how the system changes, also goes unrecorded. The extremely different results of previous experiments in the field have shown how little we know about the marine system. In addition ocean fertilisation is being considered as a possible way of extracting carbon dioxide from the atmosphere, thereby combating climate change.  The efficacy of the method and the associated risks are being hotly debated, however. Targeted and controlled experiments are needed to create a scientifically sound basis on which decisions can be made.

Do scientific iron fertilisation experiments damage the environment?

Stefan Hain: No serious researcher will intentionally cause damage to the environment. Therefore all experiments that the Alfred Wegener Institute has conducted were preceded by many years of planning and painstaking considerations.  In the case of EIFEX and LOHAFEX we intentionally fertilised small ocean eddies.  Their water masses have only little exchange with the surrounding sea. All previously conducted iron fertilisation experiments were also on a small scale and no negative effects were determined. Whether any damage to the marine environment could occur in the case of repeated, widespread fertilisation remains a matter of speculation – it has not been possible until now to investigate this.

Do legally binding national or international regulations currently exist on iron fertilisation experiments and how do you classify these as environmental policy spokesman of the Alfred Wegener Institute?

Stefan Hain: Several international organisations such as the Convention on Biological Diversity have delivered opinions and recommendations on the subject of ocean fertilisation. The London Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter (1972 and 1996 Protocol Thereto) banned commercial ocean fertilisation experiments in the year 2008. At the same time all countries were agreed that controlled, legal scientific basic research on the subject should be permitted and is needed to improve our knowledge on the carbon cycle and relevant processes in the sea. Two years later a framework was passed under this Convention that is drawn on for the assessment and approval of proposals for scientific research experiments on ocean fertilisation. It also applies to Germany.  However owing to its extensive requirements and conditions, it is hardly possible for even an institute with the size and capacity of the Alfred Wegener Institute to comply with the requirements of this assessment guide. It would no longer be possible today to carry out experiments such as EIFEX and LOHAFEX.

Does the continuation of ocean fertilisation experiments still have any useful purpose at all, and does the Alfred Wegener Institute plan any more experiments of this kind?

Stefan Hain: If we really want to understand how material flows in the ocean function under different climate conditions, if we want to check hypotheses, laboratory tests and forecasting models, then we need in situ experiments of this kind. All previous scientific results, including those currently published by EIFEX, suggest that only a small part of the annual carbon dioxide emissions would be extracted from the cycle even with widespread iron fertilisation. Therefore our principal objective must still be to reduce these carbon dioxide emissions. However if governments feel compelled to use iron fertilisation of the ocean as an additional measure to reduce the carbon dioxide cycle in the atmosphere, we must be able to make a sound scientific assessment of the possible impact and risks of ocean fertilisation. Previous experiments, such as those conducted by the Alfred Wegener Institute, have contributed greatly to this. Currently we are in the process of completely evaluating the data from past iron fertilisation experiments. If new questions arise from their findings, it will be necessary to consider whether and how these can be answered – for example using an experimental research approach.

Thank you for the interview

(Sina Löschke/Folke Mehrtens)