Iron-rich whale poo makes ocean more productive

Sunday, January 9, 2011

MELBOURNE - A new study has revealed that iron-rich whale faeces make the oceans more productive.cientists from the Australian Antarctic Division, based in Hobart, have been testing the hypothesis that enormous amounts of iron excreted by whales are similar to liquid manure, reports the Age.

This fertiliser helps phytoplankton grow, which in turn helps support a wide number of marine species including those eaten by humans.

Whales take the iron into their systems by eating massive quantities of krill, a shrimp-like crustacean.

But because whales produce blubber rather than muscle, they don’t need iron in their diet - so it passes out in their excrement.

In the days before industrial whaling there were millions of the mammals in the waters around Antarctica in the summer providing the iron to keep the ecosystem productive.

But molecular biologist Simon Jarman, with the Australian Antarctic Division, said now that whale populations had dropped to levels of just 2 to 3 percent of former numbers, there was not enough iron in the Southern Ocean.

“Removing whales from the ecosystem has probably made the whole ecosystem less productive,” said Jarman.

“‘We know there used to be a lot more fish,” he added.

To test their theories the scientists had to find areas where whales were feeding, and then be ready with a fine mesh net to scoop up the faeces.

“They will defecate eventually. ‘You can notice it fairly easily, it’s a big event,” said Jarman.

“It could be as much as half a tonne in one go, but no one has ever been actually able to measure it,” he added.

“It floats on the surface for a little while, but you have to get it as quickly as you can before it sinks,” said Jarman. (ANI)

Filed under: Science and Technology

will not be displayed