German government halts ocean-seeding experiment

A controversial Indo-German experiment in the Southern Ocean has been suspended by the German science ministry, to allow for an independent assessment of the project's environmental impact.

The German research vessel Polarstern was on its way to fertilise a patch of the Southern Ocean with iron in an effort to create a carbon sink when it received notification of the decision.

Polarstern, an icebreaker operated by the Alfred Wegener Institute for Polar and Marine Research, left Cape Town on January 7 with a team of 48 scientists on board.

The ship is still heading for the study area, an eddy northeast of South Georgia, but the Institute said that the team would start the experiment, known as LOHAFEX, only if the independent evaluation produces no objections.

LOHAFEX, a joint project with India’s National Institute of Oceanography, entails fertilising a patch of 300 km2 with 20 tons of dissolved iron sulphate in order to trigger the rapid growth of phytoplankton.

These tiny single-celled algae take up CO2 dissolved in seawater and convert the carbon into biomass, prompting the ocean’s surface layer to absorb replacement CO2 from the atmosphere to restore equilibrium.

The research team plans to monitor the impact of the phytoplankton bloom on the marine environment, and to study the fate of the biomass.

If it sinks to the ocean floor, the carbon it contains might be sequestered for centuries, which could help mitigate climate change.

Uncertainty about this process, however, and about the effects on marine ecosystems, has meant that large-scale ocean fertilisation is not currently thought to be scientifically justified.

ETC Group, an international civil society organisation based in Canada, claims that LOHAFEX violates a de facto global moratorium on ocean fertilisation adopted at a meeting of the UN Convention on Biological Diversity in May 2008, and later by parties to the London Convention of the International Maritime Organisation – the treaty governing the dumping of wastes at sea.

However, the moratorium applies to large-scale commercial schemes, and allows for approved scientific research in coastal waters.

The Alfred Wegener Institute says that the team’s own evaluations show that LOHAFEX would not damage the environment.

The surface-water iron concentrations reached during the experiment would be lower than natural iron levels in coastal marine waters, the Institute said. And the waters to be fertilised, although located offshore, contain coastal plankton species adapted to high iron concentrations.

Emma Waghorn

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