Researchers from the Australian Antarctic Division found that the naturally iron-rich whale excrement encourages growth of algae, therefore drawing more carbon dioxide from the atmosphere.
Advocates of “geo-engineering” have suggesed dumping iron filings in the sea to ‘fertilise’ the oceans but this offers a more natural process.
Steve Nicol, who helped carry out the research, said a larger population of baleen whales would boost the productivity of the whole Southern Ocean ecosystem and could improve the absorption of carbon dioxide, blamed for global warming.
“The plants love it and it actually becomes a way of taking carbon out of the atmosphere,” he said.
Mr Nicol said the idea to research whale droppings came from a casual pub chat among Antarctic scientists in Australia’s island state of Tasmania.
He exlained that iron is micronutrient in the Southern Ocean that helps algae bloom at the surface, which in turn absorbs carbon dioxide.
When krill eat the algae, and whales eat the krill, the iron ends up in whale droppings, and the iron levels are kept up in surface waters where it is most needed for more algae rather than sinking to the bottom.
“The system operates at a high level when you have this interaction between the krill, the whales and the algae and they maintain the system at a very high level of production. So it’s a self sustaining system,” he said.
He said it was not yet known how much excrement it would take have a significant impact on the Southern Ocean.
His findings come as the International Whaling Commission prepares to meet to update the law on the protection of whales. It is feared the law will be changed to allow the killing of whales in the Southern Ocean for the first time in 25 years.