Monday, March 30, 2009

Ocean fertilisation experiement fails

The notion of mass iron fertilisaiton of the oceans as a means of mitigating human induced climate change has taken a significant plunge.

New Scientist reports that the controversial Indian-German Lohafex expedition fertilised 300 square kilometres of the Southern Atlantic with six tonnes of dissolved iron. The iron triggered a bloom of phytoplankton, which doubled their biomass within two weeks by taking in carbon dioxide from the seawater. Dead bloom particles were then expected to sink to the ocean bed, dragging carbon along with them.

Instead, the bloom attracted a swarm of hungry copepods. The tiny crustaceans graze on phytoplankton, which keeps the carbon in the food chain and prevents it from being stored in the ocean sink. Researchers from the Alfred Wegener Institute for Polar and Marine Research reported that the copepods were in turn eaten by amphipods, which serve as food for squid and fin whales. Keeping carbon in the food chain increases the complexity of the process meaning that it may be difficult to control and obtain successful storage. Also ocean fertilisation could potentially increase incidence of harmful blooms and contribute to acidification.

New Scientist article on ocean fertilisation


  1. Well it was one of the possible outcomes I guess, and I would hope it had been taken into account. A significant enough set back for it not to be attempted again in the near future.

    As Jessica raised earlier about the right of humans to be altering these environments, this quite clearly shows that they should not as they do not know how the environments will respond to human stimuli.

  2. Another example, i suppose, of the dangers of oversimplifying experiments as a representation of a far more complex system.