Can fake whale poo experiment net Australian scientists a share of Elon Musk?s US$100m climate prize?

Scientists and engineers have pumped 300 litres of simulated whale poo into the ocean off Sydney as part of efforts to snag a share of Elon Musk's US$100m prize for capturing and storing carbon.

The team, known as WhaleX, carried out its first open-ocean experiment on Sunday about eight kilometres off Port Botany in New South Wales after gaining clearance from the federal government.

The 12-strong team are racing to carry out a follow-up experiment using up to 2000 litres of the simulated poo - a mix of nitrogen, phosphorus and trace elements - before the end of January.

Tesla and SpaceX founder Musk announced in February he was funding a US$100m competition through the XPrize Foundation to find methods that could safely capture and store carbon dioxide at a scale of a billion tonnes or more a year.

Musk said at the time the competition was not "theoretical" but was looking for teams that could "build real systems that can make a measurable impact and scale to a gigaton level."

WhaleX registered for the four-year competition and will send a report before February hoping to be selected for one of up to 15 "milestone" prizes of U$1m each.

Whale faeces is known as an ocean fertiliser and a food for phytoplankton. When phytoplankton grow and multiply, they absorb carbon. When they die, they sink to the ocean floor taking much of the carbon with them.