The aim of our experiment is to manipulate a speck of ocean in a natural manner in order to study and quantify the processes which shape the ever-changing, yet poorly-understood ocean ecosystems. Adding trace amounts of iron to a patch of the Southern Ocean is like watering a patch of drought-stricken landscape: plants spring to life, start growing and feeding the animals and microbes depending on them for sustenance. The analogy is not far-fetched: just as water evaporated from the oceans rains over the land and turns it green, so iron carried by dust blown off the continents settles over the ocean with a similar effect. This exchange of Gaian proportions between the continents and oceans must have persisted ever since the land was colonised by plants, some 600 million years ago. Whereas the effects of watering on land have been known since many millennia, the effects of enhancing plant growth in the vast oceans are still poorly understood. This is because we have yet to understand oceanic plant life – the minuscule unicellular algae of the phytoplankton that grow suspended in the sunlit surface layer – the way we understand the grasses, bushes and trees around us. Carrying out experiments in the real world, instead of just observing it, is a powerful tool to gather the necessary information.
Each of the dozen experiments (5 in the Southern Ocean) carried out over the past 15 years has yielded information interesting enough to be published in leading scientific journals and commented on in the science pages of newspapers. Unfortunately, albeit understandably, given its implications, attention has focussed on a single aspect of these experiments (the feasibility of carbon sequestration), and overlooked the fundamental insights on the functioning of ocean ecosystems they have also provided, not to mention the new questions they have raised.
All experiments have stimulated growth of the phytoplankton species present in the fertilised patch, but so far, only a single group known as diatoms, whose cells are encased in ornate, geometrically symmetrical shells made of glassy silicon, have increased their cell numbers and dominated biomass of the experimental blooms. The same diatoms also dominate natural blooms in productive regions, from the poles to the tropics, including the North Sea, although the reasons why the smaller, faster-growing cells of various other algal groups also present do not build up their cell numbers, are still under debate. The most likely explanation is that the diatoms are better protected, hence survive longer than the other algae which are cropped as fast as they grow, like a well-mowed lawn, by the gamut of grazers and pathogens present in the plankton. This grazer-control hypothesis of phytoplankton has been lurking in the background for decades as it can only be tested adequately by experiments such as ours which are subject to natural densities of predators and pathogens impossible to simulate in the laboratory, no matter how large the containers used. It is answers to these kinds of questions that LOHAFEX, if successfully carried out, will also provide.

All experiments have led to advances in our understanding of plankton dynamics and their effect on the chemistry of their environment. Our undertaking will corroborate or refute interpretations acquired from previous experiments and, in addition, provide a wealth of new information. We have on board teams of scientists from reputed institutes eager to bring their expertise and latest instruments to bear on documenting the changes our fertilisation will elicit on the biodiversity and production of the ocean. The information acquired from this controlled experiment will be used to interpret the reams of puzzling data gathered so far by observations of the ocean at large, ranging from microscopic evaluation of drops of water sampled by research ships, to the ocean-wide images of the sea surface provided by satellites.

We spent most of last week heading for the region north and east of the island of South Georgia because it is under the influence of coastal waters and likely to respond differently to iron addition than the oceanic waters studied in previous experiments. We intend carrying out our experiment in a stable eddy formed by meandering of the frontal jets that drive the mightiest current in the ocean – the vast, eastward flowing Antarctic Circumpolar Current –which shields the Antarctic ice cake from the warming waters of lower latitudes. Locating the fertilised patch in a stable eddy with a closed core will prevent its being drawn into filaments and merged with the surrounding waters. These eddies are visible in satellite images of sea-surface height (altimeter) daily updated on the web. They show a number of eddies in the selected region but many of them are too dynamic and short-lived for our experiment. We inspected one which lay on the way last week and found it lacking in silicic acid, the raw material of which the diatom shells are made. However, its circulation structure appeared promising. We are now engaged in comparing the structures and contents of different eddies further to the West.

Of the 30 Indian scientists on board, many are young students for whom this is their first direct contact with European culture and traditions. After the initial phase of getting to know each others’ ways (the stewardesses now know how to serve vegetarian Indian meals and interpret Indian body language expressed by head-wagging, and the Indians on their part have learned how to make German beds), the crew is charmed by the gentle friendliness of the smiling Indians who in turn, are overwhelmed by the efficiency and readiness of the crew to help as much as they can. In short, the mood on board is excellent and has not been tainted by the uncertainty now haunting our mission. On the contrary, it has served to strengthen the bonds between us and raise the high level of motivation to even greater heights, now that we know that we are performing our mission in the public limelight.

All our activity is being documented by a diligent camera man, working for a major German TV channel, whose persistent presence has not detracted from his popularity but has taught us to overlook his activity and stopped us from performing like Bollywood actors when the lights are on. Not to say we are not watching Bollywood films when time allows….

Food is important in an arduous mission like ours which could become monotonous after the first few weeks of novelty wear off, but we are lucky to have a talented Goan cook working in the kitchen, helping the two skilled German cooks and baker, one of whom received training in Indian cooking before the voyage. Indian and European cuisine is served at all meals and we are all enjoying the wide variety of excellent food. The Indian vegetarians are getting to appreciate fresh German bread and cheese and many Germans have dal, rice and curry at every meal.

We send you all warm greetings from a ship full of eager scientists bracing themselves for the tasks ahead in this remote, inhospitable corner of the globe,

Wajih Naqvi and Victor Smetacek